Description:
BACKGROUND OF THE INVENTION
This invention relates to a feed mechanism for machinery such as metallic can body trimmers, the feed mechanism being of the type operating on an automatic continuously repeating cycle to contact an article such as a can body at a feed station of a conveyor system, transport the can body to a working in this case a trimming station, retain the can body at the trimming station during open end trimming thereof, and return the now trimmed can body to the feed station for reconveyance away from the feed station for feed mechanism recycling with the next can body. More particularly, according to certain of the principles of the present invention, this invention includes a pusher mechanism for automatically carrying out the article or can body feed, working or trimmer positioning and retraction cycling having means incorporated therein positioned for sensing obstructions to proper article or can body movement in the pusher mechanism feed stroke and causing a partial axial collapse of the pusher mechanism, as well as preferably a pusher mechanism shut down in the event such an obstructing force is encountered. According to certain other of the principles of the present invention, the present invention may include a particular manner of providing a vacuum supply to the pusher mechanism required for vacuum gripping of the article or can body during at least a portion of the feed, working or trimmer positioning and retraction cycling in such a manner that a ready vacuum supply will always be available without the need for an extensive period of exhausting vacuum lines so as to provide the maximum of desired control of the article or can body during such cycling by the pusher mechanism.
Various prior forms of feed mechanisms for machinery such as metallic can body trimmers have heretofore been provided including various forms of pusher mechanisms required to transport untrimmed can bodies from feed to trimming stations and then frequently back to the feed station after the trimming operation has been completed. For instance, untrimmed can bodies may be positioned by conveyor means at a trimmer feed station and are engaged at one end thereof by the pusher mechanism for transportation, open end first to a trimming station for engagement over a trimming mandrel. A trimming operation is then performed on the can body open end with the can body ultimately being transported, preferably by vacuum gripping, back to the feed station for ultimate conveyance from the trimmer.
Obviously, for economic feasibility, the operation of the trimmer must be at relatively high speeds which means that the operation of the pusher mechanism must likewise be at relatively high speeds. Keeping in mind that the can body trimming operation is a metal trimming or cutting operation and must be performed in a relatively exacting fashion with complex and expensive metal cutting tools, the problems are further complicated by the fact that when the can body is transported to the trimming station by the pusher mechanism, the can body must be exactly and precisely telescoped over the trimmer mandrel so that the trimming operation can be successfully carried out. Thus, with the high speeds and relatively complex equipment involved, it can be readily understood that if any obstructing forces are encountered by the pusher mechanism and can body at the feed station between the feed and trimming stations and during the insertion of the can body over the trimmer mandrel, disastrous results can result involving expensive equipment and tool repair, as well as the loss of production time.
For instance, if the can body fed to the feed station is wrongly positioned, engagement thereof by the pusher mechanism and attempted movement thereof from the feed station can create an obstructing force sufficient to prevent pusher mechanism proper movement. Furthermore, the encountering of a foreign object by either or both of the pusher mechanism and can body between the feed and trimming stations can result in a relatively large obstructing force being exerted thereby. Equally as important, if the can body to be trimmed is damaged in transit to the trimming station or is improperly positioned on the pusher mechanism upon arrival at the trimming station, the relatively delicate operation of quickly telescoping the can body over the trimmer mandrel cannot be properly carried out, again presenting the possibility of many forms of obstructing forces against both the pusher mechanism and the can body. Any of the foregoing obstructing forces created can result in the severe damage to the pusher mechanism and the trimmer mechanism including the tooling thereof.
Thus, a relatively complex problem is presented as to just how to minimize the possibility of such damage occurrence. Mechanical aptitude dictates that sensing of improper positioning of a can body at the feed station and improper positioning of a can body in final trimming position at the trimming station can be relatively simply accomplished through standard sensing devices such as limit switches and the like. The major problem presented is just how to sense the encountering of obstructing forces by the pusher mechanism and can body during movement between the feed and trimming stations and during the telescoping of the can body over the trimmer mandrel into proper trimming position. It is this latter, more complex problem that is uniquely and efficiently solved by application of the principles of the present invention.
Another troublesome problem commonly encountered in the use of pusher mechanisms of metallic can body trimmers has been just how to effeciently provide a vacuum supply to the pusher mechanism at the vacuum cup on the leading end of the pusher rod in order that proper vacuum gripping of the can body being transported may take place at the exact desired time period. Depending on the particular form of pusher mechanism as well as the trimming mechanism correlated therewith, it may be desirable to vacuum grip the can body immediately after completion of the trimming operation for the withdrawal thereof by the pusher mechanism back to the feed station. At the same time, it may be desirable to establish vacuum gripping between the pusher mechanism and can body immediately at the feed station during initiation of the overall cycling and maintain such vacuum gripping throughout the overall cycling of feed, trimming and return to the feed station.
In any case, with the relatively complex, high speed operation, the vacuum supply reaction must be of minimum interval implementation. This is particuarly important in modern metallic can body trimmers where the cycling is reduced to a minimum of time interval. Furthermore, by the reduction of vacuum implementation time to a minimum, it is possible to reduce the requirements of vacuum supply to a minimum so as to minimize the costs and capacity of vacuum supply equipment. Again, it is to the solution of these vacuum supply and vacuum gripping problems to which certain of the principles of the present invention are directed.
OBJECTS AND SUMMARY OF THE INVENTION
It is, therefore, an object of this invention to provide a feed mechanism for machinery such as metallic can body trimmers wherein, according to certain of the principles of the present invention, through a unique pusher mechanism construction and related controls therefor, constant sensing for any damaging obstructing forces is maintained by inherent components of the pusher mechanism immediately upon contact of the pusher mechanism with the article or can body to be trimmed at the feed station, during such contact between the feed and working body to be trimmed by the pusher mechanism onto the trimming mandrel at the trimming station. Furthermore, upon such damaging obstructing force being sensed, the pusher mechanism automatically partially collapses so as to aid in minimizing any possibility of damage to the pusher mechanism and other machinery or trimmer components including those at the working or trimming station. For instance, a damaging obstructing force may be encountered by improper feed positioning of a particular untrimmed can body at the feed station including damaged or deformed can bodies, or such obstructing force may be created by a foreign object in the path of the pusher mechanism and untrimmed can body between the feed and trimming stations, or such obstructing force may be created by improper positioning of the untrimmed can body with the pusher mechanism causing an improper telescoping of the untrimmed can body with the trimming mandrel at the trimming station, all of which will be sensed automatically and cause the partial collapse of the pusher mechanism.
It is a further object of this invention to provide a feed mechanism for machinery such as metallic can body trimmers having the foregoing automatically collapsible pusher mechanism features wherein the entire pushing force of the pusher mechanism against the untrimmed can body necessary for engaging the can body at the feed station and transporting the same to the trimming station for telescoping over the trimming mandrel is preferably transmitted through a collapsible axial pressure reacting means such that when an obstructing force of predetermined sufficient magnitude is exerted tending to resist the can body and pusher mechanism movement, the pressure reacting means will collapse minimizing consequent damage to the various involved components as well as permitting a period of time for the operation of the equipment to be shut down. In the preferred form, the collapsible pressure reacting means is a fluid, preferably pneumatic cylinder transmitting driving forces therethrough to the pusher mechanism components engaging the can body, such driving forces being transmitted directly through the gases within the pneumatic cylinder. When the obstructing forces of sufficient magnitude are encountered, therefore, resistence to pusher mechanism and can body movement causes a collapse of the pneumatic cylinder through the compression of the gases therein minimizing, if not completely eliminating, serious damages to the various rigid parts.
It is still a further object of this invention to provide a feed mechanism for machinery such as metallic can body trimmers which not only senses damaging obstructing forces being encountered as hereinbefore set forth, such sensing being in the form of the pusher mechanism at least partially collapsing, but at the same time, such collapse of the pusher mechanism may be further sensed as to the increased pressure generated by such collapse. By such increased pressure sensing, it is possible to accomplish one or both of exhausting excess fluid pressure from the cylinder and/or automatically shutting down operation of the trimming equipment, in either case, through appropriate controls actuated thereby. For instance, where the sensing and collapsing cylinder incorporated therein is a pneumatic cylinder as in the preferred form, the encountering of the obstructing force exceeding the determined pressure of the gas within the pneumatic cylinder will cause a collapse of the cylinder by compressing the gas to higher pressures. This increase in pressure of the cylinder contained gas above a predetermined set maximum can then be further sensed to actuate appropriate controls for terminating operation of the trimming equipment while also exhausting at least the excess pressure.
It is also an object of this invention to provide a feed mechanism for machinery such as metallic can body trimmers incorporating a pusher mechanism wherein, according to certain other principles of the present invention, the necessary vacuum involved with the pusher mechanism at least during the retraction of the worked article or trimmed can body from the working or trimming station and movement thereof back to the feed station is fully controlled immediately adjacent the point of contact between the pusher mechanism and the article or can body. The result is that there are no extensive vacuum lines to be exhausted at the time the vacuum gripping of the article or can body by the pusher mechanism so as to minimize the requirements of vacuum supply. Furthermore, minimizing the space to be evacuated in order to produce the vacuum gripping, reduces the time for such vacuum gripping actuation increasing the timed actuation control of the vacuum and increasing the overall efficiency of the trimming equipment by permitting exact timed vacuum gripping control.
It is still an additional object of this invention to provide a feed mechanism for machinery such as metallic can body trimmers incorporating the pusher mechanism and the vacuum gripping of the article or can body as hereinbefore set forth wherein the unique structure of the pusher mechanism makes the same easily adaptable for full vacuum control of the article or can body throughout the entire movement and trimming cycle thereby maintaining the maximum control of the article of can body movement by the pusher mechanism so as to reduce the possibility of improper article or can body positioning and improper working or trimming thereof by the working or trimming mechanism. Again in the preferred form, the vacuum gripping of the can body by the pusher mechanism is implemented immediately upon the pusher mechanism contact with the untrimmed can body at the feed station and this vacuum gripping is maintained throughout the movement of the untrimmed can body to the trimming station, the actual metal trimming of the can body and the movement of the now trimmed can body back to the feed station. The actual vacuum control may also be incorporated directly in the ejector mechanism of the pusher mechanism so that when the untrimmed can body is first contacted by the pusher mechanism causing a withdrawal of the ejector mechanism the vacuum is automatically implemented, and when the trimmed can body is returned to the feed station by the pusher mechanism and the ejector mechanism actuated, the vacuum is automatically closed off, thereby ensuring the exact timed control of the vacuum supply in performing its can body gripping function without the need for additional timing and control equipment.
Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawings which are for the purpose of illustration only.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a metallic can body trimmer incorporating a preferred embodiment of the principles of the present invention;
FIG. 2 is a top plan view looking in the direction of the arrow 2--2 in FIG. 1;
FIG. 3 is a fragmentary vertical sectional view looking in the direction of the arrows 3--3 in FIG. 2;
FIG. 4 is an enlarged fragmentary, horizontal sectional view looking in the direction of the arrows 4--4 in FIG. 1 and showing a pusher mechanism incorporated in the trimmer of FIG. 1, the pusher mechanism being in fully withdrawn or retracted position;
FIG. 5 is an enlarged, fragmentary, vertical sectional view looking in the direction of the arrows 5--5 in FIG. 4 and showing the pusher mechanism still in fully retracted position;
FIG. 6 is an enlarged, fragmentary, vertical sectional view looking in the direction of the arrows 6--6 in FIG. 4 and showing the pusher mechanism still in the fully retracted position, but a can body positioned for contact thereby;
FIG. 7 is a fragmentary, vertical sectional view taken from the right hand portion of FIG. 6, but showing the pusher mechanism in fully retracted position immediately after the ejection of a trimmed can body thereform;
FIG. 8 is an enlarged, fragmentary, vertical sectional view looking in the direction of the arrows 8--8 in FIG. 2 and showing a can body positioned over the trimming mandrel by the pusher mechanism as during a trimming operation;
FIG. 9 is an enlarged, vertical sectional view looking in the direction of the arrows 9--9 in FIG. 8;
FIG. 10 is a fragmentary, horizontal sectional view looking in the direction of the arrows 10--10 in FIG. 9;
FIG. 11 is a vertical sectional view looking in the direction of the arrows 11--11 in FIG. 10;
FIG. 12 is a fragmentary, vertical sectional view looking in the direction of the arrows 12--12 in FIG. 10;
FIG. 13 is an enlarged, vertical sectional view looking in the direction of the arrows 13--13 in FIG. 8;
FIG. 14 is a fragmentary, vertical sectional view looking in the direction of the arrows 14--14 in FIG. 13;
FIG. 15 is a fragmentary, vertical sectional view looking in the direction of the arrows 15--15 in FIG. 14;
FIGS. 16, 17, 18, 23 and 27 are diagrammatic views showing the pusher mechanism in various progressive stages of movement from fully retracted position through the movement thereby of an untrimmed can body at the feed station to the trimming station and movement of the trimmed can body from the trimming station back to the feed station with the feed mechanism ejecting the same therefrom;
FIGS. 19, 20, 21 and 22 are diagrammatic views looking in the direction of the arrows 19--19 in FIG. 18 and showing the actual can body trimming operation; and
FIGS. 24, 25 and 26 are schematic views similar to those of FIGS. 19 through 22, but showing the scrap disposal operation.
DESCRIPTION OF THE BEST EMBODIMENT CONTEMPLATED
Referring to the drawings an embodiment of an overall metallic can body trimmer assembly is shown in FIGS. 1, 2 and 3, and includes an overall usual main frame generally indicated at 30 supporting and housing, in some cases, various working component assemblies necessary for an operable overall trimmer assembly. For purposes of convenience of description, the trimmer assembly will be described generally immediately below and the description will then be segregated into the individual working component assemblies for a specific description of each of these assemblies, finally followed by a general description of overall trimmer operation. The individual component assemblies or sub-assemblies to be specifically described are a feed and positioning mechanism assembly generally indicated at 32, a trimming mechanism assembly generally indicated at 34 and a scrap disposal assembly generally indicated at 36.
Returning to the overall trimmer assembly generally, electrical power is fed to the trimmer assembly through an electrical control panel 38 and into the main frame 30 through an enclosing electrical conduit 40. A compressed air supply is similarly fed into the main frame 30 and presented for those components requiring the same in the usual manner and as will be hereinafter specifically described particularly relative to the feed and positioning mechanism assembly 32. The main frame 30 also houses the principal electrical motor and connecting gearing systems necessary for the driving of the various component assemblies of the trimmer assembly, the operable connections therebetween being in the usual manner and as will be more clearly understood from the following specific descriptions.
The various parts and components of the trimmer assembly are formed of the usual materials and in the usual manner, all well known to those skilled in the art, except as specifically hereinafter pointed out. Furthermore, although a specific preferred embodiment of the various mechanisms is shown in the drawings and hereinafter described, it is not intended to limit the principles of the present invention to the specific embodiment. Rather the principles of the present invention should be broadly construed within the limitations defined by the following claims.
FEED AND POSITIONING MECHANISM ASSEMBLY
Referring particularly to FIGS. 1 through 8 of the drawings, the feed and positioning mechanism assembly 32 includes a generally vertical infeed guide 42 for feeding a continuous series of drawn and wall ironed untrimmed metallic can bodies 44 having closed ends 46 and open ends 48 downwardly for one at a time reception in pockets 50 of a rotatable star wheel 52. The untrimmed can bodies 44 are, at this stage and from the formation standpoint, substantially finished except for the final wall trimming operation which trims the can bodies to desired length. Furthermore, the untrimmed can bodies 44 are preferably formed of appropriate metals such as aluminum, tinplate and black iron, and have wall thicknesses in the order of 0.008ths inches thick, being useable for containing beverages, for instances, such as beer and soft drinks.
The star wheel 52 is of usual timed indexing form appropriately driven by means well known to those skilled in the art and timed for proper operation in relationship to the operation of the various other components as will be hereinafter described. As shown, the star wheel 52 rotates about a horizontal axis and moves the untrimmed can bodies 44 in timed indexing movement, counterclockwise as shown in FIG. 3 in two indexing steps to a feed station generally indicated at 54 where each particular can body is sensed by a proximity sensor 56 of usual form and in the usual manner to be sure that a can body is at the feed station for permitting operation of the other components of the assembly. As will be apparent from a later description, the particular untrimmed can body 44 at the feed station 54 is removed therefrom for trimming and then is returned as a wall trimmed can body 58 with the progressive indexing movements of the star wheel 52 in two such indexing movements releasing the trimmed can bodies 58 into the downwardly angled outfeed guide 60, where the trimmed can bodies move downwardly by gravity into an appropriate receptacle or other conveying equipment (not shown).
At the feed station 54, the untrimmed can bodies 44 are retained by the star wheel 52 with the cylindrical axis thereof horizontal, the closed ends 46 to the left and the open ends 48 to the right as shown. Preferably axially aligned with the feed station 54 is a pusher mechanism generally indicated at 62 and shown in detail in FIGS. 4 through 6. The pusher mechanism 62 in retracted position is fully to the left of the feed station 54 (FIGS. 2, 5 and 6) but is movable axially to an extended position through the feed station 54 and the appropriate pocket 50 of the star wheel 52 and ultimately to a trimming station generally indicated at 64, the trimming station, as well as a trimming mandrel 66 at said station, being a part of the trimming mechanism assembly 34 to the hereinafter described.
As shown in FIGS. 4 through 6, the pusher mechanism 62 includes an axially extending, stationary vacuum tube 68 rigidly secured in communication with a vacuum supply tube 70 at its left hand end. A vacuum flow sensor 72 is connected in communication with the interior of the vacuum supply tube 70 (FIG. 5) for sensing the continued flow therein in the usual manner and is electrically connected to appropriate controls for interrupting or shutting down operation of the trimmer in the event of sensing a continuous flow of vacuum as will be hereinafter more completely described. The vacuum tube 68 terminates at its right hand end spaced axially from the feed station 54 in an ejector stop 74, although the opening of the vacuum tube communicates centrally therethrough opening to the right of the ejector stop (FIG. 6).
A pusher tube 76 telescopes the vacuum tube 68, being axially reciprocal thereon through appropriate bearings. At the left hand end, the pusher tube 76 terminates in a radially outwardly enlarged cylinder abutment collar 78, and at the right hand end, the pusher tube terminates spaced axially beyond the right hand end of the vacuum tube 68 in a radially enlarged vacuum cup 80, open to the right. A vertically upwardly extending guide 82 is secured to the cylinder abutment collar 78 and is, in turn, upwardly received into a guide block 84 slideably guided axially in a guide slot 86 for aiding and guiding the axial reciprocal movements of the pusher tube 76.
An ejector 88 is axially slideably mounted within the vacuum cup 80 and the right hand end of the pusher tube 76, and includes a vacuum opening 90 therein opening axially to the right within the opening of the vacuum cup 80 and opening radially spaced from the ejector left hand end into the pusher tube 76. Thus, when the ejector 88 is moved to the left, as shown in FIG. 6, fully within the vacuum cup 80, the vacuum opening 90 thereof is exposed to the vacuum tube 68 and vacuum is supplied therethrough to the vacuum cup 80. When, however, the ejector 88 is moved fully forwardly or to the right projecting from the vacuum cup 80 as shown in FIG. 7, the vacuum opening 90 is closed off by the vacuum cup so that there is no vacuum flow therethrough and the vacuum tube 68 is closed off, all in a manner and for a purpose to be hereinafter described.
Directly forwardly or to the right of the cylinder abutment collar 78, the pusher tube 76 is telescoped by a fluid cylinder 92, preferably a pneumatic cylinder, which is spaced outwardly from the pusher tube and is appropriately sealed at opposite ends thereof on the pusher tube for axial slideable movement relative thereto. Such slideable sealing of the cylinder 92 at the forward or right hand end thereof, is constituted by a piston 94 secured to the pusher tube 76. At the rearward or left hand end of the cylinder 92, the interior thereof is connected in communication with a fluid supply line 96 for supplying fluid, preferably gaseous fluid such as air, under pressure to the cylinder. Also communicating into the cylinder 92 preferably at the fluid or air supply line 96 is a pressure sensor 97 and a dump valve 99, the pressure sensor 97 being for sensing fluid or air pressure within the cylinder above a predetermined pressure and having electrical connection to the main controls of the trimmer for interrupting operation of the same upon such higher predetermined pressure being sensed, and the dump valve 99 being for exhausting air pressure from the cylinder at least above said predetermined pressure, these again being for a purpose to be hereinafter described.
As best seen in FIG. 4, the rearward end of the fluid or pneumatic cylinder 92 is pivotally connected at opposite sides thereof to toggle driving arms 98 arranged such that from the position shown in FIG. 4, forward pivoting of the driving arms 98 urges the cylinder 92 forwardly or to the right and opposite pivoting of the driving arms urges the cylinder rearwardly or to the left. The pivotal stroke of the driving arms 98 is arranged so that with fluid, preferably air or some other gaseous fluid, in the cylinder 92 under pressure, preferably in the order of 40 pounds per square inch, forward pivoting of the driving arms 98 will move the cylinder axially forwardly and through the piston 94 and contained air pressure within the cylinder, will move the pusher tube 76 axially forwardly from its fully retracted position at the left of the star wheel 52 forwardly to the right through the star wheel and to the trimming station 64, with opposite movement of the driving arms 98 retracting the pusher tube or rod rearwardly to the left back to fully retracted position by abutting engagement of the cylinder with the cylinder abutment collar 78 on the pusher tub or rod. The reciprocal movement of the pusher tube 76 is, therefore totally through the fluid or air cushion or pressure within the cylinder 92 and if the pusher tube should meed an obstacle producing an obstructing force sufficient to exceed the pressure within the cylinder, the cylinder can collapse by compressing the air therein, that is, the cylinder being positively driven can continue forward movement to the right while the pusher tube becomes stationary causing the piston thereof to compress the air within the cylinder. Furthermore, by sensing the pressure of the air within the cylinder 92 through the pressure sensor 97 at the air supply line 96, when the pressure within the cylinder reaches a predetermined higher pressure indicating the obstructing force of sufficient magnitude, the entire trimmer can be automatically shut down, while at the same time, the dump valve 99 will exhaust air pressure above the predetermined higher pressure at least for cylinder pressure to stay below the predetermined higher pressure or lower.
The pusher tube or rod 76 is, therefore, guarded through this collapsing axial pressure reacting cylinder arrangement of the cylinder 92 against severe damage in the event an intervening obstructing force of sufficient magnitude is met during pusher rod forward movement at the feed station 54, between the feed station and the trimming station 64 or at the trimming station until the pusher rod is fully extended. Such an obstructing force of sufficient magnitude could be caused by improper positioning of an untrimmed can body 44 at the feed station 54 or a damaged or deformed can body being so positioned, some obstruction accidentally entering the space between the feed and trimming stations 54 and 64, some obstruction on the trimming mandrel 66 of the trimming station 64 preventing an untrimmed can body 44 being smoothly telescoped over such trimming mandrel by the pusher rod 76, or an untrimmed can body 44 being improperly positioned carried by the pusher rod 76 so that it is not positioned to be smoothly telescoped over the trimming mandrel 66 at the trimming station 64. Any of these or other obstructions could cause a sufficient obstructing force to cause collapse of the cylinder 92 and this would automatically terminate operation of the trimmer preventing serious damage to the pusher tube or rod 76 or various other components at the trimming station 64 to be hereinafter described, as well as automatically cause exhausting or dumping of excess higher air pressure preventing serious damage to the cylinder 92.
Also, it will be noted that the positioning relationship between the vacuum tube 68 and the pusher tube 76 is such that when the pusher tube is fully retracted or fully to the left as shown in FIG. 7, the ejector 88 contacts the ejector stop 74 on the vacuum tube 68 and is forced forwardly or to the right relative to the vacuum cup projecting therefrom as shown. When, however, the pusher tube 76 is in any extended position relative to the vacuum tube 68, that is, sufficient that the vacuum cup 80 carries the ejector 88 away from contact with the ejector stop 74 of the vacuum tube 68, the ejector is free to move rearwardly or to the left relative to the vacuum cup and a slight resistance or rearward movement will cause such rearward movement of the ejector. This will place the ejector 88 in its rearward position relative to the vacuum cup 80 as shown in FIG. 6.
In operation of this feed and positioning mechanism assembly 32 or this portion of the trimmer, starting with the pusher tube 76 in fully retracted position as shown in FIG. 6, the star wheel 52 indexes positioning an untrimmed can body 44 at the feed station 54 already for movement to the trimming station 64 for the trimming operation on the open end 48 thereof. At this time, the vacuum cup 80 is spaced from the untrimmed can body 44 and the ejector 88 is abutting the ejector stop 73 on the end of the vacuum tube 68 closing the ejector vacuum opening 90 and projecting axially forwardly or to the right from the vacuum cup. This, of course, is the ejecting position of the ejector 88 in which the ejector was automatically placed upon the pusher tube 76 returning to its fully retracted position at the termination of the immediately preceding cycle.
At this stage, therefore, with the pusher tube 76 in fully retracted position ready for the start of a complete cycle, the vacuum supply to the vacuum cup 80 is shut off or closed by the ejector 88 through the automatic positioning thereof and this vacuum control is immediately adjacent the vacuum cup. Furthermore, both the vacuum cup 80 and its internal ejector 88 are slightly spaced axially rearwardly from, but exactly axial aligned with the untrimmed can body 44 that has been moved into the feed station 54. Air pressure of approximately 40 psi is contained within the cylinder 92 so that an air cushion of determined pressure is maintaining the proper positioning between the cylinder and the pusher tube 76 with the rearward end of the cylinder axially abutting the cylinder abutment collar 78 on the pusher tube.
Starting a cycle, the driving arms 98 begin forward pivotal movement to the right as shown in FIG. 4, moving the cylinder 92 axially forward carrying the pusher tube 76 axially forward. The axially projecting ejector 88 first contacts the closed end 46 of the untrimmed can body 44 and since the rearward end of the ejector has moved axially away from the ejector stop 74 of the vacuum tube 68, the resistance of the untrimmed can body moves the ejector axially rearwardly telescoping the same fully within the vacuum 80. Virtually simultaneously, the vacuum cup 80 contacts the closed end 46 of the untrimmed can body 44 and with the ejector 88 spaced axially rearwardly relative to the vacuum cup 80, a vacuum supply is received from the vacuum tube 68 through the now open ejector vacuum openings 90 and into the vacuum cup 80, thereby vacuum gripping the untrimmed can body 44. This effective vacuum action takes place virtually instantaneously with the rearward telescoping of the ejector 88 and the opening of the vacuum openings 90 since no lengthy vacuum lines are required to be exhausted in view of the vacuum control being immediately adjacent the vacuum cup 80.
Continued forward or feed stroke movement of the pusher tube 76 forces the untrimmed can body 44 with its open end 48 first from its nesting in the star wheel 52 at the feed station 54 axially to the trimming station 64 and ultimately over the trimming mandrel 66 to the position shown in FIG. 8. In this pushing movement of the pusher tube 76, complete control of the untrimmed can body 44 is maintained by the described vacuum gripping thereof and as the untrimmed can body is forced to completely telescope the trimming mandrel 66, the final fully extended positioning of the cylinder 92 by the driving arms 98 is slightly beyond that necessary for the pusher tube 76 to fully telescope this untrimmed can body 44 over the trimming mandrel 66. This, therefore, moves the cylinder 92 slightly axially forwardly relative to the pusher tube 76 to the positioning of the pusher tube piston 94 shown by the phantom line 100 and the positioning of the cylinder abutment collar 78 of the pusher tube shown at phantom line 102 in FIG. 5 thereby slightly compressing the air within the cylinder and maintaining axial pressure against the untrimmed can body 44 to maintain telescoped positioning thereof on the trimming mandrel 66. Although this increase in pressure within the cylinder 92 will be sensed by the cylinder pressure sensor 97, it is not a sufficient increase to cause the cylinder pressure sensor to interrupt or shut down operation of the trimmer or the dump valve 99 to exhaust excess air pressure.
After the can body trimming operation, to be hereinafter described, the driving arms 98 begin to pivot rearwardly carrying the cylinder 92 rearwardly abutting the cylinder abutment collar 78 of the pusher tube 76 to likewise begin movement of the pusher tube rearwardly, this being the start of the return or retraction stroke. Due to the vacuum gripping of the vacuum cup 80, the now trimmed can body 58 is withdrawn from the trimming mandrel 66 and the trimming station 64. The pusher tube 76 thereby moves the trimmed can body 58 from the trimming station 64 back to the feed station 54 renested within the star wheel 52, the pusher tube approaching the end of its retraction stroke and its fully retracted position.
As shown in FIG. 7, as the pusher tube 76 is finally moved into its fully retracted position in this retraction stroke, the ejector 88 contacts the vacuum tube ejector stop 74 which moves the ejector forwardly relative to the vacuum cup 80 causing the ejector to contact the closed end 46 of the trimmed can body 58. As the pusher tube 76 finally moves in to its fully retracted position, the ejector 88 forces the trimmed can body 58 axially from vacuum gripping by the vacuum cup 80 while simultaneously closing off the vacuum supply to the vacuum cup from the vacuum tube 68 through the relative ejector forward movement. The trimmed can body 58 therefore, is now free of control by the pusher tube 76 and the star wheel 52 may be indexed to bring the next untrimmed can body 44 into the feed station 54 ready for the cycling of the mechanism.
As hereinbefore alluded to, if the untrimmed can body 44 and pusher tube 76 during the forward or feed stroke should meet one of the various possible obstructing forces hereinbefore described, the pusher tube forward movement may be stopped with the forward movement of the cylinder 92 continuing. If this obstructing force is sufficient to overcome the 40 psi pressure within the cylinder 92, the cylinder will begin to collapse, that is, relative axial movement between the pusher tube and the cylinder, thereby increasing the cylinder internal air pressure. Once this cylinder internal air pressure reaches a predetermined amount, say by relative movement between the pusher tube 76 and cylinder 92 to the phantom line positioning of the pusher tube piston 94 as shown at 103 in FIG. 6, the cylinder pressure sensor 97 senses this increased pressure to the predetermined pressure and automatically, through usual electrical connections, shuts down the trimming equipment while the dump valve 99 exhausts the excess air pressure. This, thereby, guards the trimming equipment against extensive damage.
Furthermore, if the pusher tube vacuum cup 80 ever wrongly contacts an untrimmed can body 44, or the can body closed end 46 is split or broken from improper forming, or for this or some other reason loses its vacuum gripping of the can body at any time throughout the cycling when there should be vacuum gripping by the vacuum supply being open, the resulting unusual continuous vacuum flow will be sensed by the vacuum flow sensor 72 and the pusher mechanism 62 and/or the entire trimmer shut down. Thus, this provides a further safety feature preventing component damage or improper operation.
TRIMMING MECHANISM ASSEMBLY
The trimming mechanism assembly 34 is shown in general trimmer location in FIGS. 1 and 2, and is best seen in detail in FIGS. 8 through 15. Generally, the prime components of the trimming mechanism assembly 34 or those components which actually perform the metal trimming of an untrimmed can body 44 are an outer annular anvil or cutter ring 104 having a radially extending cutting surface 106 and an internal trimmer knife 108 having a radially extending cutting surface 110, these components in can body trimming position being shown in FIGS. 10, 12 and 14. Furthermore, important to certain of the principles of the present invention, the cutter ring 104 is stationary, as is the untrimmed can body 44 during the trimming operation, while the trimmer knife 108 is rotatable about its central knife axis, the knife and its axis are rotatable about a central axis of the trimming mandrel 66 and the untrimmed can body 44 being trimmed, and is radially movable outwardly to the trimming position shown as well as movable radially inwardly of the walls of the untrimmed can body, all of which is accomplished by structure to be described immediately below.
In addition to the components hereinbefore pointed out, the trimming mechanism assembly 34 includes a main drive gear 112 rotatably driving a cutter and nipper frame 114 turning on the main frame 30 and rotatable about the central axis of the trimming mandrel 66. The cutter and nipper frame 114 terminates at the left as shown or at the trimming mandrel 66 first in an externally threaded scrap removal cylinder 116, a portion of which lies radially inwardly of the scrap disposal assembly 36, and finally in an end cap 118 which telescopes and journals a portion of the trimming mandrel 66 (FIGS. 10, 12 and 14). The trimmer knife 108 is secured to a knife shaft 120 in a manner to be hereinafter particularly described, with the knife shaft being freely journalled within a knife frame 122, which, in turn, is pivotally connected to the cutter and nipper frame 114 by securement to an axially pivotal control rod 124 pivotal on the cutter and nipper frame 114 (FIGS. 13, 14 and 15). As shown in FIGS. 14 and 15, the right end of the knife frame 122 is mounted on the right end of the control rod 124 and although the left end of the control rod is shown in FIG. 14 removed to expose other important parts of the mechanism, the left end of the knife frame 122 is similarly connected to the control rod.
Thus, the trimmer knife 108, knife shaft 120 and knife frame 122 are pivotally mounted on the cutter and nipper frame 114 for outward and inward and pivotal movement of the trimmer knife relative to the cutter and nipper frame about the axis of the control rod 124 which is widely offset from the central axis of the cutter and nipper frame. At the same time, the cutter and nipper frame 114 is rotatable about its central axis corresponding with the central axis of the trimming mandrel 66 being driven by the main drive gear 112 and carrying the trimmer knife 108 through the knife shaft 120 and knife frame 122 in this rotatable movement about the trimming mandrel central axis. In this manner, the trimmer knife 108 which is freely rotatable about its own central axis may be pivoted from its inner position inwardly of the stationary cutter ring 104 and an untrimmed can body 44 projecting through said cutter ring radially outwardly to cutting or trimming position extending radially through the untrimmed can body and against the cutter ring for rotation about the cutter ring to trim the entire circumferential length of the untrimmed can body. At the same time, the trimmer knife 108 may be retained inwardly in its retracted position free of the cutter ring 104 while still being constantly rotated about the central axis of the trimming mandrel 66 by the main drive gear 112 and the cutter and nipper frame 114.
The pivotal control of the trimmer knife 108 between its inward retracted and outward cutting or trimming positions is regulated by the mechanism shown in FIGS. 8, 13 and 14, such mechanism including a control arm 126 pivotal about the control rod 125 at one end and having a cam follower 128 rotatably mounted at the other end. The cam follower 128 bears outwardly against an internal cam surface 130 of a separately rotating cam ring 132, the cam ring being constantly rotatably driven by a cam gear 134 (FIGS. 8 and 14) at a different speed than the cutter and nipper frame 114 rotation, but about the central axis of the trimming mandrel 66. Intermediate the length of the control arm 126, an axially extending wedge 136 having an angled wedge surface 138 is received axially through an appropriate notch of the control arm and bears radially inwardly against the outer circumferential surface of the knife frame 122 so that the pivotal positioning of the trimmer knife 108, knife shaft 120 and knife frame 122 about the axis of the control rod 124 is determined by the control arm cam follower 128 and the cam ring internal cam surface 130. As shown in FIG. 13, the knife frame 122 is resiliently urged and maintained against and controlled by the wedge 136 through a radially movable plunger 140 mounted on the cutter and nipper frame 114 urged radially inwardly by a coiled spring 142.
Thus, the cam ring 152 controls the outward and inwardly pivoting of the trimmer knife 108 while this trimmer knife is being constantly rotated about the central axis of the trimming mandrel 66 through the cutter and nipper frame 114. With the particular form of internal cam surface 130 on the cam ring 132 and the particular form of trimmer of the present invention, the cam ring 132 constantly rotates two complete revolutions for every three complete revolutions of the constantly rotating cutter and nipper frame 114 about the central axis of the trimming mandrel 66 so that the trimmer knife 108 is pivoted outwardly into can body trimming position for one revolution of the cutter and nipper frame 114 and is pivoted inwardly free of any can body trimming action for two revolutions of the cutter and nipper frame. Therefore, three revolutions of the cutter and nipper frame 114 constitutes a cycle of the trimmer of the present invention.
As shown in FIGS. 14 and 15, the wedge 136 radially between the control arm 126 and the knife shaft 120 is connected to the end of an axially extending cam positioning rod 144, the opposite end of said rod being threadably engaged in an adjustment dial 146 rotatable in the end of the knife frame 122. With such structure, rotation of the adjustment dial 146 in one direction will move the wedge 136 axially in one direction relative to the control arm 126, and rotation of the adjustment dial in the opposite direction will move the wedge axially opposite relative to the control arm. Since the wedge 136 contacts the control arm 126 through the angled wedge surface 138, this axial adjustment movement of the wedge will move the knife shaft 120, knife frame 122 and trimmer knife 108 radially inwardly and outwardly relative to the central axis of the trimming mandrel 66. In this manner, therefore, the radial penetration of the trimmer knife 108 through the walls of the untrimmed can body 44 and relative to the outer stationary cutter ring 104 can be adjustably controlled.
It has been found that with the trimmer components as shown and described, penetration of the walls of the untrimmed can bodies 44 by the trimmer knife 108 to one-half to three-quarters thickness of the walls will produce a satisfactory trimming operation. It is preferred, however, to penetrate the can body walls completely and approximately one-thousandth inches radially beyond by the trimmer knife 108 where the can walls have a metal thickness of approximately eight-thousandths inches to insure a satisfactory can body trimming operation.
Referring to FIGS. 12 and 14, and more particularly to the unique mounting of the trimmer knife 108 on the knife shaft 120, it will be noted that the trimmer knife is annular and presents the radial cutting surface 110 thereof axially against the cutting surface 106 of the cutter ring 104, that is, to the left as shown in FIGS. 12 and 14. The end of the knife shaft 120 is provided with a mounting cap 148 having a radially extending mounting surface 150 axially facing the trimmer knife cutting surface 110. In the assembly as shown, the trimmer knife 108 is selectively removably tightly secured to the mounting cap 148 with the trimmer knife cutting surface 110 tightly axially abutting the mounting cap mounting surface 150, and the mounting cap 148 is, in turn, selectively removably tightly secured abutting the end surface of the knife shaft 120.
Thus, since the knife shaft 120, although controllably movable radially inwardly and outwardly during the cycling for movement of the trimmer knife 108 between its inward retracted and outward trimming positions as hereinbefore described, always remains in a set axial positioning or always extends the same set axial distance or extent. With the mounting cap 148 in the assembly always tightly abutting the end surface of the knife shaft 120 and the trimmer knife cutting surface 110 in the assembly always abutting the mounting cap mounting surface 150, the important trimmer knife cutting surface 110 will always extend radially in the same axially located radial plane or at the same exact axial location. This means that with the described assembly, the trimmer knife cutting surface 110 will always be at the exact same axial location regardless of the axial thickness of the trimmer knife 108.
The importance of the foregoing relative to the mounting of the trimmer knife 108 is that during use of the trimmer, the cutting surface 110 of the trimmer knife 108 repeatedly requires surface grinding since this is the portion of the trimmer knife with the cutting surface 106 on the cutter ring 104 that is performing the can body wall metal trimming operation. When regrinding of the cutting surface 110 of the trimmer knife 108 is required, it is merely necessary to remove the mounting cap 148 from the knife shaft 120, remove the trimmer knife 108 from the mounting cap 148, regrind the trimmer knife cutting surface 110, and reassemble the various components as described, which, most importantly, will position the reground trimmer knife cutting surface 110 at the exact same axial location and regardless of the trimmer knife 108 now being slightly axially narrower. Using the trimmer knife cutting surface 110 as the mounting reference surface as described through axial abutment of this trimmer knife cutting surface against a mounting surface always axially located at the exact same axial location, such mounting surface being the mounting cap mounting surface 150, the trimmer knife 108 in its unique assembly with the mounting cap 148 is always quickly removable and replaceable after trimmer knife cutting surface 110 grinding without the danger of altering the alignment of the trimmer knife cutting surface with the required matching cutting surface 106 of the cutter ring 104. The removal and replacement of the trimmer knife 108 can, therefore, be accomplished in a minimum of time, a far less time than has heretofore been possible with prior trimmer constructions.
A somewhat similar unique and advantageous mounting of the stationary cutter ring 104 on the main frame 30 is also provided according to the principles of the present invention as is best seen in FIGS. 10 and 12. As shown, the cutter ring 104 presents its radially extending and axial facing cutting surface 106 axially against the trimmer knife cutting surface 110 when the trimmer knife is in its outward can body wall trimming positioning. Thus, if the cutting surface 110 of the trimmer knife 108 is always in a set predetermined axial position, the facing cutting surface 106 of the cutter ring 104 must likewise always be at an exact predetermined axial positioning.
As shown, axially opposite the cutter ring cutting surface 106, the cutter ring 104 is secured axially abutting a generally L-shaped cross-section, mounting ring 152, a radially outwardly extending leg portion of the mounting ring radially outwardly of the cutter ring 104 also axially abutting a compensating spacer ring 154. The compensating spacer ring 154 is, except for its abutments, axially slideable relative to both the cutter ring 104 and the mounting ring 152 extending axially radially adjacent portions of both. Intermediate the cutter ring 104, the compensating spacer ring 154 axially abuts a register ring 156 telescoping and radially outwardly abutting an axial portion of the cutter ring 104.
The register ring 156 by its inward radial abutment with the cutter ring 104 radially positions the cutter ring in exact location relative to the other components at the trimmer station 64, and is, in turn, radially outwardly recess registered with the main frame 30. At the same axial side of the register ring 156 with which it abuts the compensating spacer ring 154, the register ring axially abuts a register spacer ring 158 which, in turn, axially abuts the main frame 30, the register ring 156 and register spacer ring 158 being secured to the main frame 30. To complete the unique mounting assembly of the cutter ring 104, a clamping ring 160 is secured axially abutting the main frame 30 with a portion extending radially inwardly into axial alignment with a portion of the mounting ring 152, there being radially adjustable clamping studs 162 extending axially through the clamping ring 160 and adjustable tightly axially against the mounting ring 152.
With this described assembly and with the various components remaining with their exact same respective sizes, the cutter ring 104 will always be positioned in the exact same radial and axial location, and particularly, the cutting surface 106 of the cutter ring 104 will always be positioned in the same axial location or radial plane and relative to the cutting surface 110 of the trimmer knife 108 with which it must cooperate to accomplish the can body wall metal trimming operation. Obviously, the cutter ring 104 will always be retained in the same radial location by the register ring 156, but more important for purposes of the present invention, the cutter ring cutting surface 106 will always be retained in the same axial location and relative to the trimmer knife 108 by the cutter ring clamping to the mounting ring 152, the abutment of the mounting ring with the compensating spacer ring 154 and the abutment of the compensating spacer ring with the register ring 156 which is clamped in a pre-determined axial position on the main frame 30. If nothing is altered, this exact axial positioning of the cutter ring cutting surface 106 will remain by the tight clamping of the clamping studs 162 of the clamping ring 160 against the mounting ring 152, but just as with the cutting surface 110 of the trimmer knife 108, the cutting surface 106 of the cutter ring 104 requires grinding and if all of the other components of the assembly remain the same, the grinding of the cutter ring cutting surface 106 will move this cutting surface axially away relative to the trimmer knife cutting surface.
Thus, according to the principles of the present invention and with the unique assembly shown and described, when the cutter ring 104 is removed for grinding the radial cutting surface 106 thereof, the compensating spacer ring 154 is also removed and a radially extending surface thereof is ground an exact equivalent amount. For convenience, it is preferred to form the cutter ring 104 and the compensating spacer ring 154 with the exact same axial dimensions so that these two rings can be positioned with the compensating spacer ring 154 telescoping the cutter ring 104 on the same grinder and with the radially extending surfaces thereof radially aligned so that the grinding of the cutter ring cutting surface 106 will automatically grind the aligned radially extending surface of the compensating spacer ring 154 the exact same amount. In any event, with the exact same grinding of the cutter ring cutting surface 106 and one of the radially extending surfaces of the compensating spacer ring 154, when the various components of the assembly are reassembled and axially clamped by the clamping studs 162 of the clamping ring 160, the now reground cutting surface 106 of the cutter ring 104 will be returned to its exact same axial position and relative to the cutting surface 110 of the trimmer knife 108. Therefore, the realignment of the cutting surface 106 of the cutter ring 104 after regrinding is automatic with this unique assembly, and the disassembly, grinding and reassembly may be accomplished without time consuming realignment being necessary and the overall operation can be conducted in far less time than has heretofore been possible with prior trimmer constructions.
In operation of the trimming mechanism assembly 34 constituting a portion of the trimmer of the present invention, the pusher tube 76 of the pusher mechanism 62 as previously described telescopes an untrimmed can body 44 over the trimming mandrel 66 at the trimming station 64 into the position shown in FIGS. 8, 10, 12 and 14, but during this untrimmed can body telescoping, although the untrimmed can body extends through the cutter ring 104, the trimmer knife 108 is in its radially inward retracted position by the cam follower 128 of the control arm 126 contacting a portion of the internal cam surface 130 of the cam ring 132 which is of maximum radial dimension. Once the pusher mechanism 62 completes this axial telescoping of the untrimmed can body 44 over the trimming mandrel 66 into position extending through the cutter ring 104, the pusher mechanism retains the untrimmed can body axially against the trimming mandrel 66 with the described slightly increased air pressure of the pneumatic cylinder 92, and also preferably the vacuum gripping from the vacuum cup 80 as likewise described. Since the pusher tube 76 including its vacuum cup 80 of the pusher mechanism 62 are non-rotatable, this axial pressure against and vacuum gripping of the untrimmed can body 44 retains both the untrimmed can body and the trimming mandrel 66 stationary throughout the trimming operation which, particularly with the stationary cutter ring 104, adds greatly to the accuracy and efficiency of the trimming operation.
Immediately following the final positioning of the untrimmed can body 44 over the trimming mandrel 66, the cam follower 128 of the control arm 126 arrives circumferentially at and moves radially inwardly onto the lesser radial dimensioned portion of the internal cam surface 130 on the cam ring 132 thereby forcing the knife frame 122 and knife shaft 120 pivotally radially outwardly carrying the trimmer knife 108 radially outwardly to initially pierce the walls of the untrimmed can body 44 in the manner shown in FIGS. 10, 12 and 14. Since the cutter and nipper frame 114 is continuously rotating about the central axis of the trimming mandrel 66 and relative to the main frame 30, as the trimmer knife 108 pierces the walls of the stationary untrimmed can body 44 it is carried circumferentially around the can body walls in approximately one complete circumference, it being pointed out that one complete circumferential movement of the trimmer knife 108 would not be required in view of the fact that the trimmer knife is circular so as to span a circumferential distance. This circumferential movement of the trimmer knife 108 with the trimmer knife cutting surface 110 acting against the stationary cutter ring cutting surface 106 will sever the desired can body wall portion from the can body open end 48 ultimately resulting in a scrap ring 164 being formed by the severed can body wall portion which is disposed of in a manner to be hereinafter described. Immediately after the severing of the scrap ring 164 from the untrimmed can body 44 so as to form the trimmed can body 58, the pusher mechanism 62 through the previously described vacuum gripping withdraws the now trimmed can body 58 from the trimming mandrel 66 and from the trimming station 64 returning it to the feed station 54 while the trimmer knife 108 is retracted radially inwardly as controlled by the internal cam surface 130 of the cam ring 132.
SCRAP DISPOSAL ASSEMBLY
The general location of the scrap disposal assembly 36 in the overall trimmer assembly is shown in FIGS. 2, 8, 10 and 14, and the particulars thereof are shown in detail in FIG. 11. Referring particularly to FIG. 11, the scrap disposal assembly 36 includes preferably diametrically opposite nipper assemblies generally indicated at 166 mounted on the cutter and nipper frame 114 and, therefore, constantly rotatable with the cutter and nipper frame about the central axis of the trimming mandrel 66 at an axial location axial adjacent the cutting surface 106 of the cutter ring 104. The nipper assemblies 166 are, therefore, radially outwardly of a portion of the externally threaded scrap removal cylinder 116 previously described (FIG. 14) and extend generally radially outwardly from the location of the scrap rings 164 being severed from the untrimmed can bodies 44 at the trimming station 64.
As shown in FIG. 11, each of the nipper assemblies 166 is substantially the same and each includes a frame portion 168 secured to the cutter and nipper frame 114 so as to be stationary relative to said frame, although constantly rotatable therewith about the central axis of the trimming mandrel 66. A nipper actuator 170 is pivotally connected to each of the frame portions 168 normally urged resiliently outwardly by springs 172 against the frame portions 168 and controlled in the limits of their inward and outward movements by pins 174 received through the nipper actuators and through enlarged openings 176 of the frame portions. The nipper actuators 170 have radially outwardly facing and generally circumferentially extending camming surfaces 178 axially aligned with an actuating roller 180 movable by appropriate controls well known to those skilled in the art upwardly and downwardly below the cutter and nipper frame 114 at this nipper assembly location.
An actuator pin 182 is mounted in each of the nipper actuators 170 peripherally abutting outer ends of radially inwardly extending and radially reciprocal nipper rods 184 radially slideably received through the frame portions 168. The nipper rods 184 are retained generally radially movable with the pivotal movements of the nipper actuators 170, but slightly pivotal relative thereto, by keeper pins 186 of the nipper actuators 170 received through notches 188 of the nipper rods 184. The inner or cutting ends of the nipper rods 184 upon pivotal movement of the nipper actuators 170 and radial inward and outward reciprocation of the nipper rods 184, slide radially along scrap positioners 190 circumferentially covering scrap slots 192 of the scrap positioners when the nipper rods 184 are moved inwardly and being free and radially outwardly of the scrap slots when the nipper rods are moved outwardly. As shown in FIG. 11, the scrap slots 192 extend circumferentially through the scrap positioners 190 and as shown in FIGS. 12 and 14, such scrap slots open axially at least in the axial direction toward the cutter ring 104 which is the axial direction from which the untrimmed can bodies 44 are inserted over the trimming mandrel 66 and through the cutter ring.
Thus, as best seen in FIGS. 11 and 12, as the untrimmed can bodies 44 are moved to the trimming station 64 and telescoped fully over the trimming mandrel 66 ready for the trimming operation as hereinbefore described, the wall portions at the open ends 48 of the untrimmed can bodies are at least partially axially received in the scrap slots 192 of the nipper assemblies 166, the actuating roller 180 at this time being in its lowered position and the trimmer knife 108 being in its inward retracted position. At this time, the scrap positioners 190 being secured to the frame portions 168 are constantly rotating about the central axis of the trimming mandrel 66 with the cutter and nipper frame 114 and during such movement, the untrimmed can bodies 44 remain stationary as described while the scrap positioners 190 rotate with the end portions of the untrimmed can bodies remaining in the scrap slots 192. This relative movement continues during the outward camming of the tirmmer knife 108 and the axial can body trimming operation to produce the now trimmed can bodies 58 and the scrap rings 164.
Immediately upon a trimming operation being completed on a particular untrimmed can body 44 producing a particular scrap ring 164, however, this scrap ring 164, being free of the stationary now trimmed can body 58, now rests fully on and begins rotation with the nipper assemblies 166. At this time the actuating roller 180 is moved upwardly from the position shown in full lines to the position shown in phantom lines in FIG. 11. As the first of the constantly rotating nipper assemblies 166 arrives at the actuating roller 180, the actuating roller rolls circumferentially along the nipper actuator camming surface 178 pivoting the nipper actuator 170 radially inwardly and moving the nipper rod 184 inwardly to slide radially along the scrap positioner scrap slot 192 severing the scrap ring 164 at this particular location. As soon as that nipper assembly 166 moves circumferentially beyond the location of the actuating roller 180, the nipper actuator 170 pivots back radially outwardly withdrawing the nipper rod 184.
Ultimately the other nipper assembly 166 carrying the now rotating scrap ring 164 therewith arrives at the location of the actuating roller 164 therewith arrives at the location of the actuating roller 180 and the same severing operation is repeated with the actuating roller 180 being lowered downwardly to its non-actuating full line position of FIG. 11 after the second severing or nipping operation. Thus, each particular scrap ring 164 is severed or nipped into two separate pieces in one complete revolution of the nipper assemblies 166, each nipper assembly performing its scrap severing or nipping operation at a different time spaced by one half revolution of the cutter and nipper frame 114. Furthermore, as the scrap ring 164 is cut into the separate pieces, these pieces are immediately thrown outwardly by centrifugal force away from the can body trimming components due to the scrap ring rotation. Referring to FIGS. 1 and 2, the severed portions of the scrap ring 164, after expending of the centrifugal force, fall downardly by gravity into the scrap chute 194 and ultimately therethrough outward of the trimmer into an appropriate receptacle.
The purpose of the peripheral threading of the scrap removal cylinder 116 which lies radially inwardly of the nipper assemblies 166 and is constantly rotating with the cutter and nipper frame 114 is for the purpose of tending to move the scrap ring 164 axially away from the stationary cutter ring 104 and further into the scrap slots 192 of the scrap positioners 190, if at any time after separation from the can, the scrap ring does not attain the rotational speed of the cylinder 116, such as if the scrap ring or any portion of it adheres to or is thrown into the stationary cutter ring 104. In other words, this threaded peripheral surface of the scrap removal cylinder 116 is threaded in the direction such that the threads appear to thread axially away from the particular now trimmed can body 58 and toward the closed sides of the scrap slots 192 in the scrap positioners 190 during the constant rotation of the cutter and nipper frame 114 so that the particular scrap ring 164, while it is stationary or rotating at less speed than the scrap removal cylinder 116 and becomes disoriented so as to contact this cylinder, tends to be urged toward and more deeply into the scrap slots 192 effectively positioning the scrap ring fully within the scrap slots for severing thereof and tending to prevent the scrap ring or resulting severed scrap pieces from moving in the opposite axial direction where they could interfere with the various can body trimming components and positioning surfaces. Also, this threaded peripheral surface of the scrap removal cylinder 116 which is constantly covered with oil during operation of the trimmer forms an oil break preventing the several scrap pieces from sticking thereto and allowing the same to separate from the cylinder 116 by centrifugal force or gravity and to fall downwardly into the scrap chute 194.
OVERALL OPERATION OF TRIMMER
Referring to the diagrammatic views of FIGS. 16 through 27, a single overall cycle of the trimmer will be described which is complete in exactly three revolutions of the cutter and nipper frame 114, as previously pointed out.
Starting with FIG. 16, the star wheel 52 has indexed and is positioning an untrimmed can body 44 at the feed station 54 axially aligned with the pusher mechanism 62. The pusher tube 76 of the pusher mechanism 62 is fully withdrawn or retracted so as to be fully to the left as shown, and the ejector 88 has contacted the ejector stop 74 forcing the ejector to extend into ejecting position projecting from the vacuum cup 80. Thus, the pusher tube 76 is exactly in its fully retracted position and reversing ready to start a cycle.
As shown in FIG. 17, the pusher tube 76 has started its feed stroke and the vacuum cup 80 thereof has contacted the closed end 46 of the untrimmed can body 44. During this contact of the pusher tube vacuum cup 80 with the untrimmed can body 44, the can body closed end 46 as well as the pusher tube momentum has forced the ejector 88 rearwardly, or to the left, relative to the vacuum cup, so that the ejector vacuum opening 90 is open into communication with the vacuum tube 68. This, thereby, immediately causes tight vacuum gripping of the pusher tube vacuum cup 88 of the untrimmed can body 44.
As shown in FIG. 18, the pusher tube 76 continues its forward feed stroke movement to the right pushing the untrimmed can body 44 from the star wheel 52 and telescoping the untrimmed can body fully over the trimming mandrel 66 at the trimming station 64. It will be noted that to this point in the cycle, although the cutter and nipper frame 114 is continously rotating, the trimmer knife 108 remains retracted radially inwardly and the nipper assemblies 166 remain inactive not actuated. The axial telescoping of the untrimmed can body 44 over the trimming mandrel 66 at the trimming station 64 by the pusher tube 76 has, however, inserted the untrimmed open end 48 of the untrimmed can body 44 through the cutter ring 104 and into the scrap positioners 190 (FIGS. 24, 25 and 26) of the nipper assemblies 166. The untrimmed can body 44 and trimming mandrel 66 remain circumferentially stationary held by the vacuum gripping and axial pressure of the pusher tube 76, the cutter ring 104 remains at all times stationary, and the retracted trimmer knife 108 and non-actuated nipper assemblies 166 continue to rotate in view of the continuous rotation of the cutter and nipper frame 114.
As shown in FIG. 19, immediately upon the FIG. 18 positioning of the untrimmed can body 44 at the trimming station 64, the trimmer knife 108 begins to be cammed radially outwardly toward the wall of the untrimmed can body 44, the trimmer knife and nipper assemblies 166 continuing to rotate, but the nipper assemblies remaining non-actuated by the lowered position of the actuating roller 180. In FIG. 20, the trimmer knife 108 has moved fully radially outwardly piercing the wall of the untrimmed can body 44 acting against the cutter ring 104 (FIG. 18) and starting to produce the scrap ring 164 by the can body trimming operation. In FIG. 21, the trimmer knife 108 has partially circumferentially rotated to continue the can body trimming operation and in FIG. 22, the trimmer knife 108 has completed its one circumferential revolution fully severing the scrap ring 164 from the open end 48 of the untrimmed can body 44 ready for trimmer knife radially inward retraction and with the actuating roller 180 moving upwardly into position for actuating the nipper assemblies 166.
As shown in FIG. 24, as the trimmer knife 108 moves radially inwardly, the first of the nipper assemblies 166 with the scrap ring 164 now rotating therewith arrives at the now raised actuating roller 180 so that as this nipper assembly passes the actuating roller, the camming surface 178 of the nipper actuating 170 contacts the actuating roller forcing the nipper rod 184 radially inwardly past the scrap positioner 190 cutting or nipping one side of the scrap ring 164. The continuous rotation of the cutter and nipper frame 114 causes the same actuation of the second nipper assembly 166 as shown in FIG. 25, so that the cut or nipped portions of the scrap ring 164 fall downwardly away from the trimming mechanism and scrap disposal assemblies 34 and 36. Immediately thereafter, as shown in FIG. 26, the actuating roller 180 is withdrawn downwardly into non-actuating position.
While the nipping action of the scrap ring 164 by the scrap disposal assembly 36 was taking place, the pusher mechanism 62 was being actuated to carry out its retraction stroke to the left and through the vacuum gripping thereof, the withdrawal of the now trimmed can body 58 from the trimming station 64 to the feed station 54. As shown in FIG. 23, the pusher tube 76 has just withdrawn the trimmed can body 58 fully into the star wheel 52, and as shown in FIG. 27, the ejector 88 has ultimately contacted the ejector stop 74 moving the ejector axially forwardly relative to the vacuum cup 80 causing the vacuum supply to the vacuum cup to be cut off or terminated and the ejector contacting the closed end 46 of the trimmed can body 58 rejecting the trimmed can body from the pusher mechanism 62. The pusher mechanism 62 has, therefore, now completed its retraction or withdrawal stroke and is in position ready for the start of the next cycle, while the star wheel 52 begins its indexing movement to carry the trim can body 58 away from the feed station 54 and position the next untrimmed can body 44 at the feed station as in FIG. 16, thereby completing the cycle.
Although the unique feed mechanism principles of the present invention have been illustrated and described herein in relation to a metallic can body trimmer, it is not intended thereby to limit the principles of the present invention to trimmers or other can making equipment alone. It is obvious to those skilled in the art that the improvements of the present invention are applicable to many forms of equipment of various types so that the scope of the present invention should be broadly construed.