DISCONNECT ARRANGEMENT FOR MULTI-UNIT PRINTING PRESS
United States Patent 3691948
A disconnect arrangement for a multi-unit sheet fed press in which one of the transfer cylinder gears is shifted axially out of mesh with the gear on an adjacent cylinder while remaining in mesh with the gear on another adjacent cylinder thereby interrupting the press drive train and permitting individual operation of the units. The cylinders associated with the gears which have been disengaged are so dimensioned and arranged that they may be individually rotated without the grippers on either cylinder interfering with the other cylinder.
US Patent References:
Offset printing press
Barber - June 1935 - 2003798
Multi-colour sheet printing machine
Koch - April 1955 - 2705918
Drive for multicolor press
Harrold - May 1955 - 2707914
PLURAL INDEPENDENTLY OPERABLE MOTOR DRIVE ARRANGEMENT IN PRINTING PRESS
Lee - January 1971 - 3557692
/3606800.html
Treff et al. - September 1971 - 3606800
Offset printing press
Barber - June 1935 - 2003798
Multi-colour sheet printing machine
Koch - April 1955 - 2705918
Drive for multicolor press
Harrold - May 1955 - 2707914
PLURAL INDEPENDENTLY OPERABLE MOTOR DRIVE ARRANGEMENT IN PRINTING PRESS
Lee - January 1971 - 3557692
/3606800.html
Treff et al. - September 1971 - 3606800
Inventors:
Southam, Donald L. (Brecksville, OH)
Weigl, William (Brecksville, OH)
Kacmarcik, Thomas J. (Parma Heights, OH)
Weigl, William (Brecksville, OH)
Kacmarcik, Thomas J. (Parma Heights, OH)
Application Number:
05/130082
Publication Date:
09/19/1972
Filing Date:
04/01/1971
View Patent Images:
Export Citation:
Assignee:
Harris-Intertype Corporation (Cleveland, OH)
Primary Class:
Other Classes:
101/483, 101/248
International Classes:
B41F13/00; B41F7/06
Field of Search:
101/136-145,152-157,174,183,184,185,216-218,232,248,409,410,426
Primary Examiner:
Fisher, Reed J.
Claims:
What is claimed is
1. In a sheet fed multi-unit printing press having a plurality of individual printing units and including a pair of spaced vertical side frames,
2. The press of claim 1 wherein the teeth on the gear on the other of said adjacent cylinders have an axial dimension greater than the teeth of the gear on said transfer cylinder whereby said transfer cylinder gear remains in mesh with said gear on said other adjacent cylinder when shifted axially out of mesh with the gear on said one adjacent cylinder.
3. The press of claim 1 wherein said transfer cylinder, its gear and grippers are all mounted for axial movement as a unitary assembly,
4. The press of claim 1 and further including means operatively associated with said transfer cylinder gear enabling shifting movement of that gear in only one rotated position thereof.
5. The press of claim 2 wherein the axial dimension of said gear teeth on said adjacent cylinder is greater by an amount approximately equal to the distance through which said transfer cylinder gear is shifted.
6. A method of disconnecting and individually operating the printing units of a multi-unit printing press of the type having a plurality of individual printing units supported between a pair of spaced side frames, at least one sheet transfer cylinder journaled on a horizontal axis between said side frames for transferring printing stock from one printing unit to the next and a pair of adjacent cylinders angularly spaced around said transfer cylinder, a train of drive gears for said press with each of said cylinders having a gear at one end thereof constituting a portion of the drive train, all of said cylinders having sets of interdigitating sheet grippers thereon for successively transferring sheets by means of said grippers from one printing unit to the next, motor means for operating said drive train to drive all of the units of said press during the printing operation and auxiliary motor means associated with individual printing units to drive each unit individually, said method comprising the steps of:
7. The method of claim 6 wherein the step of shifting the transfer cylinder gear includes shifting the transfer cylinder axially, said method further including the steps of:
8. The method of claim 7 wherein the step of positioning the grippers comprises rotating the cylinders to a position where the grippers are displaced from a sheet transfer position.
1. In a sheet fed multi-unit printing press having a plurality of individual printing units and including a pair of spaced vertical side frames,
2. The press of claim 1 wherein the teeth on the gear on the other of said adjacent cylinders have an axial dimension greater than the teeth of the gear on said transfer cylinder whereby said transfer cylinder gear remains in mesh with said gear on said other adjacent cylinder when shifted axially out of mesh with the gear on said one adjacent cylinder.
3. The press of claim 1 wherein said transfer cylinder, its gear and grippers are all mounted for axial movement as a unitary assembly,
4. The press of claim 1 and further including means operatively associated with said transfer cylinder gear enabling shifting movement of that gear in only one rotated position thereof.
5. The press of claim 2 wherein the axial dimension of said gear teeth on said adjacent cylinder is greater by an amount approximately equal to the distance through which said transfer cylinder gear is shifted.
6. A method of disconnecting and individually operating the printing units of a multi-unit printing press of the type having a plurality of individual printing units supported between a pair of spaced side frames, at least one sheet transfer cylinder journaled on a horizontal axis between said side frames for transferring printing stock from one printing unit to the next and a pair of adjacent cylinders angularly spaced around said transfer cylinder, a train of drive gears for said press with each of said cylinders having a gear at one end thereof constituting a portion of the drive train, all of said cylinders having sets of interdigitating sheet grippers thereon for successively transferring sheets by means of said grippers from one printing unit to the next, motor means for operating said drive train to drive all of the units of said press during the printing operation and auxiliary motor means associated with individual printing units to drive each unit individually, said method comprising the steps of:
7. The method of claim 6 wherein the step of shifting the transfer cylinder gear includes shifting the transfer cylinder axially, said method further including the steps of:
8. The method of claim 7 wherein the step of positioning the grippers comprises rotating the cylinders to a position where the grippers are displaced from a sheet transfer position.
Description:
This invention relates to a multi-unit sheet fed rotary printing press and, more particularly, to a disconnect arrangement in which a transfer cylinder gear is shifted out of engagement with a gear in the press drive train to permit individual rotation of the press units.
Although the invention will be described with particular reference to a multi-unit three cylinder offset sheet fed press in which a plurality of transfer cylinders are used to transfer a sheet from one unit to the next, it will be appreciated that the invention may be used with any press in which it is desired to disconnect an intergeared cylinder from adjacent cylinders having interdigitated gripper fingers.
In operating multi-unit printing presses, it frequently is necessary or desirable to operate the individual units of the press independently and various disconnect mechanisms have been proposed for this purpose. However, several factors must be considered in designing a suitable disconnect arrangement, among which are the desirability of driving solely through meshing gear teeth during normal printing operation, the need for proper retiming of the units upon reconnect and the avoidance of gripper interference during individual operation of the printing units.
It is an object of this invention to provide a disconnect arrangement for a sheet fed multi-unit printing press having a plurality of individual printing units with a train of drive gears for the press, a sheet transfer cylinder having a gear at one end constituting a portion of the drive train, a pair of adjacent cylinders angularly spaced around the transfer cylinder gear and sets of interdigitating sheet grippers on each cylinder for successively transferring sheets by means of the grippers from one cylinder to the next with each set of grippers being supported on its associated cylinder for pivoting movement between a radially outward position and a radially inward position. In accordance with the invention, actuator means are provided for shifting the transfer cylinder gear axially out of mesh with the gear on one of the other cylinders thereby interrupting the drive train and disconnecting the printing units from each other with the two disengaged cylinders being so dimensioned and arranged that the radially outer position of the grippers on each cylinder clears the periphery of the other cylinder whereby the cylinders may be rotated independently without gripper interference.
In accordance with the preferred form of the invention, one of the adjacent cylinders has a gear which is double the width of the gears on the other adjacent cylinder and the transfer cylinder whereby axial shifting of the transfer cylinder gear maintains that gear in mesh with the double width gear while breaking mesh with the gear on the other cylinder. The preferred embodiment of the invention further contemplates that the transfer cylinder and its grippers will be shifted axially as a unitary assembly with the transfer cylinder gear and that the spacing of the grippers in each of the sets of grippers will be such that the grippers on the transfer cylinder will be interdigitated with the grippers on the adjacent cylinders both before and after axial shifting movement of the transfer cylinder.
Referring now to the drawings wherein like reference numerals indicate like parts in the various views:
FIG. 1 is a schematic illustration in side elevation of a typical multi-unit press in which the principles of this invention may be used;
FIG. 2 is a sectional view taken generally along line 2--2 of FIG. 1;
FIG. 3 is a schematic illustration of the grippers on one of the cylinders and the required clearance to avoid gripper interference;
FIG. 4 is a fragmentary view illustrating the relationship of the transfer cylinder gear with a keeper ring on an adjacent gear;
FIG. 5 is a fragmentary top plan view of the keeper ring.
Referring now more in detail to the drawings, FIG. 1 illustrates a four-color multi-unit sheet fed press, indicated generally by the reference numeral 10, and which includes individual printing units 12, 14, 16 and 18. As is conventional, each of the units includes an appropriate inker mechanism and dampener mechanism indicated generally by the reference numeral 20 together with a plate cylinder 22, a blanket cylinder 24 and impression cylinder 26. A first transfer cylinder 28 is positioned between the impression cylinders of the two units 12,14. A second transfer unit comprising three transfer cylinders 30, 32, 34 is operative to transfer sheets from the second unit 14 to the third unit 16 while another transfer cylinder 36 transfers the sheets between units 16, 18. The transfer cylinders 28 and 36 are conventional in construction and operation so further description of these cylinders is believed unnecessary.
As is conventional, all of the cylinders in the press 10 are intergeared so that a single main drive motor M may be used to drive the first transfer cylinder 28 and thereby all of the other cylinders in the press. The intergeared relationship of the transfer cylinders 30, 32, 34 is illustrated in FIG. 2 wherein it will be seen that each of the cylinders is supported for rotation between a pair of vertical side frames 38. Cylinder 32 is supported in the side frames 38 by a shaft 40 which in turn is supported by suitable bearings at either end thereof. The shaft 40 and the bearings supporting the shaft are slidable in the side frame so that the cylinder 32 may be shifted axially, as will be described hereinafter.
Secured for rotation with each of the cylinders 30, 32, 34 are gears 42, 44, 46, respectively. As is apparent from FIG. 2, the gear 46 is double the width of gears 42 and 44 but the gears otherwise lie in a common plane.
It is contemplated that the transfer cylinder 32 will be disconnected from the press gear drive train thereby dividing the press into two separate pairs of printing units. Disconnect of the transfer cylinder 32 is accomplished by shifting the gear 44 axially out of mesh with gear 42 while remaining in mesh with gear 46. The shifting movement of the gear 44 may be accomplished by various actuator means. One suitable actuator is a double acting hydraulic cylinder, schematically illustrated at 48, which is connected to the shaft 40. Selective actuation of the actuator 48 shifts the shaft 40 to the right, as viewed in FIG. 2, thereby displacing the gear 44 to a position out of mesh with the gear 42. Thereafter, units 12 and 14 may be driven independently of printing units 16 and 18 by separate motors, not shown.
To reconnect the units in the proper timed relationship it is necessary that the gear 44 be brought back into mesh with gear 42 at precisely the same position it occupied upon disconnect. To this end, the gear 42 is provided with a keeper ring 50 on the axial outer face thereof. The keeper ring comprises a generally flat annular plate having a generally circular periphery 52 formed at a radius r 1. The radius r 1 is at least large enough to interfere with the mating gear 44 but is normally axially offset from the teeth of that gear. As shown, the radius r 1 actually corresponds to the outside radius of the gear 42. It will be appreciated that the keeper ring with the radius r 1 radially overlaps the teeth on the gear 44 at the point of mesh between the gears 42,44 and thereby precludes axial shifting movement of the gear 44.
To permit shifting of the gear 44 axially, notwithstanding the radially overlapping relationship between the keeper ring and the gear, there is provided on the periphery 52 a short arcuate interrupted segment 54 which is formed on a radius r 2 and which is slightly greater than the radius of the addendum circle of the gear 44. When the gears 42,44 have been rotated to a position in which the meshing engagement between the two gears precisely corresponds with the arcuate interrupted segment 54, as shown in FIG. 4, the gear 44 may be shifted axially with the teeth of the gear passing through the space provided by segment 54. For a more detailed disclosure of the keeper ring and the manner in which it cooperates with the gears during connect and disconnect, reference may be had to copending application Ser. No. 130,708, filed Apr. 2, 1971, and assigned to the assignee herein.
To facilitate angular alignment of the gear 44 with the arcuate segment 54, each of the gears 42,46 is provided with sensing blocks, not shown, which may be of a conventional construction and which are adapted to cooperate with a pair of sensing probes 58,60. The sensing blocks and probes comprise a part of a conventional proximity switch sensing head. The angular position of the sensing blocks and the probes is such that when the gear 44 and the keeper plate 50 are in the position shown in FIG. 4, the proximity switch sensing mechanism will indicate that the cylinders are in a disconnect or reconnect position. An appropriate circuit may be employed with the switch sensing head so that actuation of the cylinder 48 is prevented except when the proximity switches indicate the cylinders are in the proper rotational position.
In the preferred form of the invention, it is contemplated that the cylinder 32 will be shifted axially as a unit with the gear 44. Accordingly, provision must be made both for avoiding interference between the sets of adjacent gripper fingers on adjacent cylinders as the cylinder 32 is shifted axially and interference between the grippers and the periphery of the adjacent cylinder as the cylinders are individually rotated. As is conventional, the cylinder 30 has a pair of angularly spaced gaps 62 in which sets of grippers 64 are positioned. Similarly, cylinder 32 has a pair of gaps 66 in which grippers 68 are positioned while cylinder 34 has a pair of gaps 70 with grippers 72 positioned therein. FIG. 3 illustrates the manner in which the grippers, for example, grippers 68 are supported on a pivotable shaft 74 whereby the grippers pivot between a radially inward position where they are in engagement with gripper pads or posts 76 and a radially outer position where they are radially spaced from the gripper pads. Each set of grippers is controlled in its movements by spring means, not shown, and a cam and follower arrangement. One such cam and follower arrangement for the grippers 68 is schematically illustrated in FIG. 2 wherein a cam follower 78 is adapted to cooperate with a stationary cam 80 secured to the side frame 38. A similar cam and follower arrangement would be provided for each of the sets of grippers on the other cylinders 30,34.
As is apparent from FIG. 2, the grippers 68 are axially spaced along the cylinder 32 in such manner that they are offset from and interdigitated with the grippers 64 and 72 on the adjacent cylinders 30,34 during normal press operations. As the cylinder 32 is shifted axially, it is necessary that interference between grippers 68 and grippers 64 and 72 be avoided. This may be accomplished by spacing grippers 64,72 an amount x sufficient to accommodate the axial shift of the grippers 68. Thus, gripper 68a, for example, is illustrated as being positioned between the grippers 64,72 on cylinders 30,34 when in the normal position shown in full lines. The spacing x of grippers 64,72 is such that, upon shifting of cylinder 32, gripper 68a moves to a position shown in dotted lines which is still between the adjacent grippers.
On the other hand, if the spacing of grippers 64,72 is less than that required to avoid gripper interference, the keeper ring 50 may be angularly positioned such that cylinder 32 can be shifted axially only in a position such as that shown in FIG. 1 where the grippers on the respective cylinders are angularly offset from each other. In this position of the cylinders, the grippers are not interleaved and the cylinder 32 may be shifted axially without concern for interference of the grippers. However, upon completion of shifting movement of cylinder 32, the grippers 68 must be positioned to be interdigitated with the grippers 72 and 64 so that when the printing units are operated independently, the grippers on adjacent cylinders do not interfere.
In addition to avoiding interference between grippers on adjacent cylinders, it is also necessary to assure that the grippers on one cylinder do not engage the periphery of the next adjacent cylinder. Since cylinders 32 and 34 remain in meshing engagement, these two cylinders continue to operate in timed relationship. In addition, cam follower 78 is constructed such that the operative portion of the follower is axially elongated thereby to maintain operative engagement with the cam 80 in the axially shifted position of cylinder 32. Hence, cylinders 32,34 cooperate in precisely the same manner in the disconnect position as during normal printing operations and interference between the grippers on one cylinder with the periphery of the adjacent cylinder does not present a problem.
However, this is a potential problem for cylinders 30 and 32. Accordingly, each of cylinders 30 and 32 as shown in FIGS. 2 and 3 are reduced in diameter so that there is defined between the two cylinders a relieved space or clearance into which the grippers of both cylinders may open without engaging the periphery of the adjacent cylinder. This condition is illustrated in FIG. 3 wherein, for example, cylinder 32 is illustrated as rotating relative to cylinder 30 and the grippers 68 may move to the dotted line position without engaging the periphery of the cylinder 30.
While the invention has been described with reference to a specific embodiment, it is not intended that either the illustrated embodiment or the terminology employed in describing it is to be limiting; rather, it is intended to be limited only by the scope of the appended claims.
While a double width gear 46 has been illustrated as one means for maintaining operative engagement between the teeth of the gears 44,46, while breaking mesh between gears 42,44, it is to be appreciated that other gearing arrangements for accomplishing the same result may be employed.
With the construction shown, since none of the press cylinders are locked in stationary position while the gear teeth are out of mesh, it is possible to engage and disengage the separate sections of the press while the press is running. Preferably, this would be done at slow speed. If the keeper ring 50 is removed and the gripper finger spacings are such that any given finger stays between two adjacent grippers on the adjacent cylinder in both the engaged and disengaged positions, no part interferences are possible and the shifting of the cylinders can be accomplished without regard to the rotational positions of the cylinders.
On engagement of the separate press sections, the motors can be driven at slightly different speeds until the gear teeth properly align. Sensing means provided to sense this relationship can then be caused to actuate the gears into engagement in the usual manner while the units are being driven. Since interference of parts is impossible, further sensing means can be provided as a final assurance that the gears have correctly entered into mesh. This latter sensing means could be made to provide a control interlock to prevent the feeding of sheets or running of the press at high speed unless re-engagement has been made with the correct teeth in mesh. All of the above may also be made to occur with one press section stopped and the other being turned over at a very slow speed.
Although the invention will be described with particular reference to a multi-unit three cylinder offset sheet fed press in which a plurality of transfer cylinders are used to transfer a sheet from one unit to the next, it will be appreciated that the invention may be used with any press in which it is desired to disconnect an intergeared cylinder from adjacent cylinders having interdigitated gripper fingers.
In operating multi-unit printing presses, it frequently is necessary or desirable to operate the individual units of the press independently and various disconnect mechanisms have been proposed for this purpose. However, several factors must be considered in designing a suitable disconnect arrangement, among which are the desirability of driving solely through meshing gear teeth during normal printing operation, the need for proper retiming of the units upon reconnect and the avoidance of gripper interference during individual operation of the printing units.
It is an object of this invention to provide a disconnect arrangement for a sheet fed multi-unit printing press having a plurality of individual printing units with a train of drive gears for the press, a sheet transfer cylinder having a gear at one end constituting a portion of the drive train, a pair of adjacent cylinders angularly spaced around the transfer cylinder gear and sets of interdigitating sheet grippers on each cylinder for successively transferring sheets by means of the grippers from one cylinder to the next with each set of grippers being supported on its associated cylinder for pivoting movement between a radially outward position and a radially inward position. In accordance with the invention, actuator means are provided for shifting the transfer cylinder gear axially out of mesh with the gear on one of the other cylinders thereby interrupting the drive train and disconnecting the printing units from each other with the two disengaged cylinders being so dimensioned and arranged that the radially outer position of the grippers on each cylinder clears the periphery of the other cylinder whereby the cylinders may be rotated independently without gripper interference.
In accordance with the preferred form of the invention, one of the adjacent cylinders has a gear which is double the width of the gears on the other adjacent cylinder and the transfer cylinder whereby axial shifting of the transfer cylinder gear maintains that gear in mesh with the double width gear while breaking mesh with the gear on the other cylinder. The preferred embodiment of the invention further contemplates that the transfer cylinder and its grippers will be shifted axially as a unitary assembly with the transfer cylinder gear and that the spacing of the grippers in each of the sets of grippers will be such that the grippers on the transfer cylinder will be interdigitated with the grippers on the adjacent cylinders both before and after axial shifting movement of the transfer cylinder.
Referring now to the drawings wherein like reference numerals indicate like parts in the various views:
FIG. 1 is a schematic illustration in side elevation of a typical multi-unit press in which the principles of this invention may be used;
FIG. 2 is a sectional view taken generally along line 2--2 of FIG. 1;
FIG. 3 is a schematic illustration of the grippers on one of the cylinders and the required clearance to avoid gripper interference;
FIG. 4 is a fragmentary view illustrating the relationship of the transfer cylinder gear with a keeper ring on an adjacent gear;
FIG. 5 is a fragmentary top plan view of the keeper ring.
Referring now more in detail to the drawings, FIG. 1 illustrates a four-color multi-unit sheet fed press, indicated generally by the reference numeral 10, and which includes individual printing units 12, 14, 16 and 18. As is conventional, each of the units includes an appropriate inker mechanism and dampener mechanism indicated generally by the reference numeral 20 together with a plate cylinder 22, a blanket cylinder 24 and impression cylinder 26. A first transfer cylinder 28 is positioned between the impression cylinders of the two units 12,14. A second transfer unit comprising three transfer cylinders 30, 32, 34 is operative to transfer sheets from the second unit 14 to the third unit 16 while another transfer cylinder 36 transfers the sheets between units 16, 18. The transfer cylinders 28 and 36 are conventional in construction and operation so further description of these cylinders is believed unnecessary.
As is conventional, all of the cylinders in the press 10 are intergeared so that a single main drive motor M may be used to drive the first transfer cylinder 28 and thereby all of the other cylinders in the press. The intergeared relationship of the transfer cylinders 30, 32, 34 is illustrated in FIG. 2 wherein it will be seen that each of the cylinders is supported for rotation between a pair of vertical side frames 38. Cylinder 32 is supported in the side frames 38 by a shaft 40 which in turn is supported by suitable bearings at either end thereof. The shaft 40 and the bearings supporting the shaft are slidable in the side frame so that the cylinder 32 may be shifted axially, as will be described hereinafter.
Secured for rotation with each of the cylinders 30, 32, 34 are gears 42, 44, 46, respectively. As is apparent from FIG. 2, the gear 46 is double the width of gears 42 and 44 but the gears otherwise lie in a common plane.
It is contemplated that the transfer cylinder 32 will be disconnected from the press gear drive train thereby dividing the press into two separate pairs of printing units. Disconnect of the transfer cylinder 32 is accomplished by shifting the gear 44 axially out of mesh with gear 42 while remaining in mesh with gear 46. The shifting movement of the gear 44 may be accomplished by various actuator means. One suitable actuator is a double acting hydraulic cylinder, schematically illustrated at 48, which is connected to the shaft 40. Selective actuation of the actuator 48 shifts the shaft 40 to the right, as viewed in FIG. 2, thereby displacing the gear 44 to a position out of mesh with the gear 42. Thereafter, units 12 and 14 may be driven independently of printing units 16 and 18 by separate motors, not shown.
To reconnect the units in the proper timed relationship it is necessary that the gear 44 be brought back into mesh with gear 42 at precisely the same position it occupied upon disconnect. To this end, the gear 42 is provided with a keeper ring 50 on the axial outer face thereof. The keeper ring comprises a generally flat annular plate having a generally circular periphery 52 formed at a radius r 1. The radius r 1 is at least large enough to interfere with the mating gear 44 but is normally axially offset from the teeth of that gear. As shown, the radius r 1 actually corresponds to the outside radius of the gear 42. It will be appreciated that the keeper ring with the radius r 1 radially overlaps the teeth on the gear 44 at the point of mesh between the gears 42,44 and thereby precludes axial shifting movement of the gear 44.
To permit shifting of the gear 44 axially, notwithstanding the radially overlapping relationship between the keeper ring and the gear, there is provided on the periphery 52 a short arcuate interrupted segment 54 which is formed on a radius r 2 and which is slightly greater than the radius of the addendum circle of the gear 44. When the gears 42,44 have been rotated to a position in which the meshing engagement between the two gears precisely corresponds with the arcuate interrupted segment 54, as shown in FIG. 4, the gear 44 may be shifted axially with the teeth of the gear passing through the space provided by segment 54. For a more detailed disclosure of the keeper ring and the manner in which it cooperates with the gears during connect and disconnect, reference may be had to copending application Ser. No. 130,708, filed Apr. 2, 1971, and assigned to the assignee herein.
To facilitate angular alignment of the gear 44 with the arcuate segment 54, each of the gears 42,46 is provided with sensing blocks, not shown, which may be of a conventional construction and which are adapted to cooperate with a pair of sensing probes 58,60. The sensing blocks and probes comprise a part of a conventional proximity switch sensing head. The angular position of the sensing blocks and the probes is such that when the gear 44 and the keeper plate 50 are in the position shown in FIG. 4, the proximity switch sensing mechanism will indicate that the cylinders are in a disconnect or reconnect position. An appropriate circuit may be employed with the switch sensing head so that actuation of the cylinder 48 is prevented except when the proximity switches indicate the cylinders are in the proper rotational position.
In the preferred form of the invention, it is contemplated that the cylinder 32 will be shifted axially as a unit with the gear 44. Accordingly, provision must be made both for avoiding interference between the sets of adjacent gripper fingers on adjacent cylinders as the cylinder 32 is shifted axially and interference between the grippers and the periphery of the adjacent cylinder as the cylinders are individually rotated. As is conventional, the cylinder 30 has a pair of angularly spaced gaps 62 in which sets of grippers 64 are positioned. Similarly, cylinder 32 has a pair of gaps 66 in which grippers 68 are positioned while cylinder 34 has a pair of gaps 70 with grippers 72 positioned therein. FIG. 3 illustrates the manner in which the grippers, for example, grippers 68 are supported on a pivotable shaft 74 whereby the grippers pivot between a radially inward position where they are in engagement with gripper pads or posts 76 and a radially outer position where they are radially spaced from the gripper pads. Each set of grippers is controlled in its movements by spring means, not shown, and a cam and follower arrangement. One such cam and follower arrangement for the grippers 68 is schematically illustrated in FIG. 2 wherein a cam follower 78 is adapted to cooperate with a stationary cam 80 secured to the side frame 38. A similar cam and follower arrangement would be provided for each of the sets of grippers on the other cylinders 30,34.
As is apparent from FIG. 2, the grippers 68 are axially spaced along the cylinder 32 in such manner that they are offset from and interdigitated with the grippers 64 and 72 on the adjacent cylinders 30,34 during normal press operations. As the cylinder 32 is shifted axially, it is necessary that interference between grippers 68 and grippers 64 and 72 be avoided. This may be accomplished by spacing grippers 64,72 an amount x sufficient to accommodate the axial shift of the grippers 68. Thus, gripper 68a, for example, is illustrated as being positioned between the grippers 64,72 on cylinders 30,34 when in the normal position shown in full lines. The spacing x of grippers 64,72 is such that, upon shifting of cylinder 32, gripper 68a moves to a position shown in dotted lines which is still between the adjacent grippers.
On the other hand, if the spacing of grippers 64,72 is less than that required to avoid gripper interference, the keeper ring 50 may be angularly positioned such that cylinder 32 can be shifted axially only in a position such as that shown in FIG. 1 where the grippers on the respective cylinders are angularly offset from each other. In this position of the cylinders, the grippers are not interleaved and the cylinder 32 may be shifted axially without concern for interference of the grippers. However, upon completion of shifting movement of cylinder 32, the grippers 68 must be positioned to be interdigitated with the grippers 72 and 64 so that when the printing units are operated independently, the grippers on adjacent cylinders do not interfere.
In addition to avoiding interference between grippers on adjacent cylinders, it is also necessary to assure that the grippers on one cylinder do not engage the periphery of the next adjacent cylinder. Since cylinders 32 and 34 remain in meshing engagement, these two cylinders continue to operate in timed relationship. In addition, cam follower 78 is constructed such that the operative portion of the follower is axially elongated thereby to maintain operative engagement with the cam 80 in the axially shifted position of cylinder 32. Hence, cylinders 32,34 cooperate in precisely the same manner in the disconnect position as during normal printing operations and interference between the grippers on one cylinder with the periphery of the adjacent cylinder does not present a problem.
However, this is a potential problem for cylinders 30 and 32. Accordingly, each of cylinders 30 and 32 as shown in FIGS. 2 and 3 are reduced in diameter so that there is defined between the two cylinders a relieved space or clearance into which the grippers of both cylinders may open without engaging the periphery of the adjacent cylinder. This condition is illustrated in FIG. 3 wherein, for example, cylinder 32 is illustrated as rotating relative to cylinder 30 and the grippers 68 may move to the dotted line position without engaging the periphery of the cylinder 30.
While the invention has been described with reference to a specific embodiment, it is not intended that either the illustrated embodiment or the terminology employed in describing it is to be limiting; rather, it is intended to be limited only by the scope of the appended claims.
While a double width gear 46 has been illustrated as one means for maintaining operative engagement between the teeth of the gears 44,46, while breaking mesh between gears 42,44, it is to be appreciated that other gearing arrangements for accomplishing the same result may be employed.
With the construction shown, since none of the press cylinders are locked in stationary position while the gear teeth are out of mesh, it is possible to engage and disengage the separate sections of the press while the press is running. Preferably, this would be done at slow speed. If the keeper ring 50 is removed and the gripper finger spacings are such that any given finger stays between two adjacent grippers on the adjacent cylinder in both the engaged and disengaged positions, no part interferences are possible and the shifting of the cylinders can be accomplished without regard to the rotational positions of the cylinders.
On engagement of the separate press sections, the motors can be driven at slightly different speeds until the gear teeth properly align. Sensing means provided to sense this relationship can then be caused to actuate the gears into engagement in the usual manner while the units are being driven. Since interference of parts is impossible, further sensing means can be provided as a final assurance that the gears have correctly entered into mesh. This latter sensing means could be made to provide a control interlock to prevent the feeding of sheets or running of the press at high speed unless re-engagement has been made with the correct teeth in mesh. All of the above may also be made to occur with one press section stopped and the other being turned over at a very slow speed.