Title:
Packaging machine
United States Patent 2381505


Abstract:
This invention relates to a packaging machine. The invention has for an object to provide a novel and improved packaging machine having a material supply hopper from which the material is withdrawn to be packaged and in which I provision is rpade for maintaining a substantially constant level...



Inventors:
Lindholm, Arthur W.
Application Number:
US44462442A
Publication Date:
08/07/1945
Filing Date:
05/27/1942
Assignee:
PNEUMATIC SCALE CORP
Primary Class:
Other Classes:
53/52, 99/DIG.10, 111/38, 198/524, 222/64, 241/34, 250/215, 250/223R, 250/575, 318/480, 414/296
International Classes:
B65B57/14
View Patent Images:



Description:

This invention relates to a packaging machine.

The invention has for an object to provide a novel and improved packaging machine having a material supply hopper from which the material is withdrawn to be packaged and in which I provision is rpade for maintaining a substantially constant level of material in the supply hopper including control mechanism for terminating the delivery of material to the supply hopper when the latter is filled with a predetermined maxi- 1 mum amount of material and for terminating the operation of the packaging machine when the supply of material in the hopper falls below a predetermined minimum amount to the end that a substantially uniform head of material may be I maintained in the supply hopper.

With this general object in view and such others as may hereinafter appear the invention consists in a packaging machine and in the various structures, arrangements, and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification. In the drawings the invention has been illustrated as einbodied in a packaging machine for filling cartons with weighed loads wherein Fig. 1 is a side elevation of such a machine, some of the parts being shown in cross section; Figs. 2 and 3 are detailed views of modified forms of material feeding apparatus to be referred to; Fig. 4 is a sectional side elevation illustrating a modification of the apparatus shown in Fig. 1; and Fig. is a plan view in cross section of the supply hopper shown in Fig. 4.

In general, the present packaging machine embodies a supply hopper for storing a supply ofthe material to be packaged and from which the material flows downwardly through a conduit to be deposited in successive cartons conveyed beneath the same. The successive loads of material thus withdrawn may be formed in various known manners as by weighing or measuring.

Provision is made for maintaining a substantially constant level of material in the material supply hopper in order to maintain the pressure head of the material therein substantially constant during the formation of successive loads being packaged. In this manner inaccuracies in the rate of flow of the material downwardly from the supply hopper through the conduit are avoided and more accurately formed loads are produced.

Referring now the drawings which as above stated illustrate the different features of the invention as embodied in a packaging machine of the type wherein the loads are formed by weighing, the machine is provided with a material supply hopper II to which material is delivered by a conveyer 12 from any suitable source of supply, and from which the material is withdrawn by suitable material feeding mechanism, indicated generally at 14, to be introduced into a carton IS resting upon one end of a scale beam IM.

For purposes of illustration, the invention has been shown as embodied in a commercial weighing machine of the type illustrated and described in the United States patent to Howard, No.

i 1,893,622, January 10, 1933, to which reference may be had for a more complete disclosure of the operation of such weighing machine. In general, the illustrated weighing machine may include an intermittently operated package mov0 ing mechanism including package pusher arms 20 mounted upon an endless chain 22 adapted to move a carton onto the scale pan 24 of the scale beam 18 during one period of operation, and control mechanism, indicated generally at 26, adapted to open and close the shutters 28, 30 of the material feeding mechanism 14 during another period of operation. In the automatic weighing machine the cartons are supplied to the machine upon an inlet conveyer 32 and successive 20 cartons are transferred onto a platform 34 into. the path of the pusher arms 20 by a transfer member 35. As fully described in the Howard patent above referred to, the machine is controlled to operate in successive cycles through 25 connections actuated by the movement of the scale beam It whereby the shutters 28, 30 are closed and the package moving cycle of operation is initiated when the scale makes its weight.

Thereafter when the package moving cycle has 0o been completed, the shutters 23, 30 are again opened to permit the material to flow by gravity Sinto a fresh carton delivered onto the scale. The material feeding mechanism 14 may be provided with the usual stirrers 36, 38 to facilitate the 35 flow, of the material therethrough. As herein shown, the machine may be driven by an electric motor 41 through its pulley 42 connected by a belt 45 to a drive pulley 46 on the machine. As will be hereinafter described, the electric motor A 40 forms part of a circuit arranged to be opened to stop the machine when the weight of the material in the supply hopper falls below a predetermined minimum amount.

Prom the description thus far, it' will be observed that the material is withdrawn from the 45 supply hopper I by the feeding mechanism II, the material falling by gravity through the bottom of the hopper as it is required by the feeding mechanism. In the embodiment of the invention, as illustrated in Fig. 1, the discharge end 48 50 of the hopper is loosely inserted into the top of the feeding mechanism, forming a telescopic connection, to permit the hopper to be raised or lowered with relation to the feeding mechanism in accordance with the weight of the material in 55 the hopper as will be described.

As illustrated in Pig. 1, one form of mechanism for conveying the material from its source and delivering it to the supply hopper may comprise the conveyer 12 which.may include a conduit It 60 having an inlet 52 and an outlet 54 and through which an endless conveying element *5 is arranged to run. The conveying element runs over an idler II at one end of the conduit and a driven sprocket II at the other end, such a conveyer being of a commercial form known in the trade and operating in accordance with the principles disclosed in the United States Redler Reissue Patent No. 18,445, to which reference is made. As herein shown, the conveyer Is driven by an electric motor 12 having a pinion 84 in mesh with a gear Is fast on the sprocket shaft 6I. The electric motor 62 forms part of a circuit arranged to be opened to stop the conveyer when the weight of the material in the hopper exceeds a predetermined maximum, as will be hereinafter described.

For the purpose of the present Invention, it is suffcient to state that the conveying element II when moved through the conveyer casing operates to convey the material in a continuous stream from the Inlet 52 to be discharged through the outlet 54.

As herein illustrated, see Pig. 1, the material supply hopper II may be supported upon compression springs 16, coiled about studs 72 extending from a platform 74, the latter being supported by rods 75 depending from the floor above.

The platform 74 is provided with an opening 71 through which the lower portion of the hopper extends. The studs 72 are slidingly fitted through bearings 80 provided in a flanged portion 12 of the hopper 10. Thus, the hopper is free to move vertically under the influence of the weight of the material in the hopper.

Provision is made for controlling the operation of the supply conveyer 12 and the operation of the weighing machine in accordance with the weight of the material in the supply hopper II as Indicated by the vertical movement of the hopper. As herein shown, a circuit 84 to the conveyer motor 62 includes a switch I1 having a stationary contact II and a movable contact II, the latter being pivotally mounted in the switch supporting bracket 12 attached to the stationary platform 14. The switch is normally held in its closed position as illustrated in Fig. 1, by a common spring 14 extended between the switch arm 96 and a similar switch arm I8 forming part of a similar switch 110 included in a circuit Il2 leading to the machine motor 40. A switch arm engaging stud 114 vertically and adjustably mounted in a bracket I$ is secured to the side of the hopper II, and normally, when the hopper is filled with the normal amount of material, the stud 104 is disposed between the two arms 6I, II without engaging either. In operation, if the hopper 10 is filled above a predetermined height, the additional weight of the material will cause the hopper to descend. The stud 104 will then engage the arm tI and-open the circuit 14 at the contacts 88, 00 .thereby stopping the conveyer motor 62 and consequently stopping the delivery of the material to the hopper. During the operation of the machine, continued withdrawals of material from the hopper will cause the hopper to rise under the influence of the springs 71 and the contacts I8, 90 will be reestablished to again feed material to the hopper.

In the event that the supply of material at its source is depleted, or, if for some other reason, the conveyer 12 fails to replenish the material withdrawn from the hopper, continued withdrawal of material will cause the hopper to become abnormally light, and when this occurs, the springs 71 will raise the hopper and the stud 104 will engage the arm 1I and open the circuit 112 at contacts III, III, thereby stopping the machine motor 41. When the required amount of material has been delivered to the hopper by the conveyer 12, the contacts III, II will be reestablished to again start the weighing machine.

Thus, a substantially constant level of material is maintained in the hopper II through the use of the limiting switches 86, III operated by vertical movement of the hopper effected by the relative weight of the material therein. The usual cutout switches 112, 114 may be provided in the circults 84, 182 respectively, in order to permit operation of the conveyer 12 or the weighing machine without going through the limiting switches, when such operation is necessary.

Referring now to Pigs. 2 and 3, modified forms of the mechanism for delivering material to the supply hopper II are herein illustrated. In Pig. 2, a vibratory feeder III is employed. Material is delivered through a funnel III from a source of supply onto the vibratory feeder which is operated through a vibratory motor 12i to deliver the material into the hopper II. The vibratory motor 120 is provided with leads 122, 124 which may be included in the circuit 84 in place of the motor 62 in order to start and stop the vibration of the vibratory motor 120 in accordance with the amount of material in the hopper 1I, as above described, whereby the feed of the material into the hopper may be thus controlled.

Another modification of the mechanism for delivering material to the supply hopper II, as illustrated in Fig. 3, may comprise a funnel 12i through which the material may flow by gravity 85 from the source of supply into the hopper II. As herein shown, the funnel 126 Is provided with a gate or shutter 128 which may be operated by a solenoid 138 having leads 132, 134 which may be connected in the circuit 84, as above described, to control the feed of the material in accordance with the amount of material in the hopper.

Referring now to Figs. 4 and 5, a modified form of the mechanism for controlling the amount of material in the supply hopper may comprise mechanism for maintaining a substantially constant level of the material therein. As herein shown, such ,hechanism may include a fixed supply hopper 140 having light sensitive cells 142, 144 cooperating with light sources 141, 148 respectively, mounted at different levels in the hopper.

The light sensitive elements are enclosed in casings 160, 152 secured to the outside of the hopper and are provided with condensing lenses 154, 11 secured to the inner wall of the hopper for cons5 centrating the rays of light from the light sources onto the photo-electric cells. The light sources are likewise enclosed in suitable casings III, 111 and are protected from the material in the hopper by glass panels 112, 164.

The hopper is provided with a cover 11 and material may be delivered through an offset opening 167 therein, as shown in Fig. 5. The material may be delivered by a conveyer I1I which may be driven by a motor 170, the latter being diagrammatically shown in the wiring circuit in Fig. 4. Power is supplied to the motor through the main leads 172, 174 through a solenoid operated switch 171. When the material in the hopper rises above the level of the upper light sensitive cells 142 it will intercept the light ray from the source 141 and as a result, a relay mechanism which may be of any well-known type indicated at 178 becomes operative to actuate the solenoid 110 to open the circuit to the conveyer motor 171 at the switch IT7 to thereby terminate the delivery of material to the hopper. Continued withdrawals of material from the hopper will lower the level therein to again expose the photo-electric cell 142 to the ray of light 146 whereupon the switch 175 will again be closed to start the conveyer 188.

The photo-electric cell 142 is connected to the relay I18 by the leads 182, 184. Leads 185, 181 connect the main leads to the relay. The solenoid 180 is connected to the relay by leads 187, 189. The source of light 146 is supplied with current through the leads 190, 192. In operation, the relay 178 is adapted to close the circuit within the relay to operate the solenoid III when the light ray to the photo-electric cell 142 is cut off.

Normally, the photo-electric cell will not operate the relay when it is receiving a sufficient amount of light. As above described, the incoming supply of material to the hopper is disposed in an offset position so that the incoming stream of material will not operate to cut off the light ray.

On the other hand, should the material in the hopper become depleted below the level of the lower light sensitive cell 144, to expose the cell to the ray of light from the source 148, a relay mechanism 135 will become operative to actuate a solenoid 196 to open the circuit to the machine motor 198 at the switch 210. As herein shown, power is supplied to the motor I 8 from the main leads 112, 174 and through leads 202, 204. The connections to the relay 1II include the leads 218, 208 from the main leads, the leads 210,212, to the photo-electric cell 144 and the leads 214, 216 to the solenoid III. The light source 148 is connected to the power supply through leads 218,220.

Normally, when the light source is cut off by the material in the hopper, the switch 200 will remain closed to drive the machine. However, when the photo-electric cell 144 is exposed to the light the relay III will operate to energize the solenoid I18 to open the circuit at the switch 200.

Thus, the level of the material in the hopper is maintained at a substantially constant level, within the limits of the different levels of the light sensitive cells 142, 144.

From the above description, it will be observed that provision is made in the present weighing machine for assuring a substantially constant head of material in the supply hopper whereby the gravitational flow from the hopper is maintained substantially uniform thus effecting a substantially constant impact force upon the scale Fbeam to the end that errors in weights which 'have heretofore accompanied variations in the flow of the material being weighed, may be reduced to a minimum.

This application is a division of my co-pending application, Serial No. 327,755, filed April 4, 1940.

Having thus described the invention what is claimed is: 1. A packaging machine having in combination, material feeding means, a supply hopper to which material is fed by said feeding means, a conduit leading downwardly from the supply hopper and through which material may fall by gravity, means for forming successive loads of the material withdrawn from the supply hopper through said conduit, and control means for maintaining a substantially constant amount of material in said supply hopper whereby to effect a substantially uniform gravitational flow of material from said feeding means, said control means including means for terminating the delivery of material to the supply hopper when the latter becomes filled in excess of a predetermined amount and means for terminating the operation of the load forming means when the hopper becomes depleted below a predetermined and less amount of material.

2. A packaging machine having in combination, material feeding means, a supply hopper to which material is fed by said feeding means, a conduit leading downwardly from the supply hopper and through which material may fall by gravity, means for forming successive loads of the material withdrawn from the supply hopper through said conduit, and control means for maintaining a substantially constant amount of material in said supply hopper whereby to effect a substantially uniform gravitational flow from said feeding means, said control means including means for supporting said hopper adapted to permit the latter to move vertically under the influence of the weight of the material in the hopper, and means operatively connected to said hopper for terminating the delivery of material thereto when the weight of the material in the hopper exceeds a predetermined amount and for initiating such delivery when said weight falls below said amount, and means for terminating the operation of the load forming means when said weight falls below a predetermined but substantially less amount.

3. A packaging machine having in combina0o tion, material feeding means, a supply hopper to which material is fed by said feeding means, a conduit leading downwardly from the supply hopper and through which material may fall by gravity, means for forming successive loads of the material withdrawn from the supply hopper through said conduit, and control means for maintaining a substantially constant amount of material in said supply hopper whereby to effect - a substantially uniform gravitational flow of material from said feeding means, said control means including means for supporting said hopper adapted to permit the latter to move vertically under the influence of the weight of the material in the hopper, a pair of limiting switches adapted to be operated by the vertical movement of said hopper for terminating the delivery of material thereto when the weight of the material therein exceeds a predetermined maximum and for terminating the operation of the load formo ing means when said weight falls below a predetermined minimum.' 4. A packaging machine having in combination, material feeding means, a supply hopper to which material is fed by said feeding means, a conduit leading downwardly from the supply hopper and through which material may fall by gravity, means for forming successive loads of the material withdrawn from the supply hopper through said conduit, and control means for maintaining a substantially constant level of material in said supply hopper whereby to effect a substantially uniform fravitational flow of material from said feeding means, said control means including means for terminating the deU livery of material thereto when the level thereof exceeds a predetermined maximum height and means for terminating the operation of the load forming means when said level is reduced below a predetermined minimum height.

5. A packaging machine having in combination, material feeding means, a hupply hopper to which material is fed by said feeding means a conduit leading downwardly from the supply hopper and through which material may fall by t7 gravity, means for forming successive loads of the material withdrawn from the supply hopper through said conduit, and control means for maintaining a substantially constant level of material in said supply hopper whereby to effect a substantially uniform gravitational flow of material from said feeding means, said control means including photo-electric means responsive to the changes in the level of said material for terminating the delivery of material to said hopper when the level exceeds a predetermined maximum height and for terminating the operation of the load forming means when said level is reduced below a predetermined minimum height.

6. A packaging machine having in combination, material feeding means, a supply hopper to which material is-fed by said feeding means, a conduit leading downwardly from the supply hopper and through which material may fall by gravity, means for forming successive loads of the material withdrawn from the supply hopper through said conduit, and control means for maintaining a substantially constant level of material in said supply hopper whereby to effect a substantially uniform gravitational flow of material from said feeding means, said control means including means for terminating the delivery of material thereto when the level thereof exceeds a predetermined maximum height, and for causing said delivery to be resumed when the material level falls below said maximum height, and means for terminating the operation of the load forming means when the level falls below a different and lower height.

7. A packaging machine having in combination, material feeding means, a supply hopper to which material is fed by said feeding means, a conduit leading downwardly from the supply hopper, means for forming successive loads of the material withdrawn from the supply hopper 4 through said conduit, and control means for maintaining a substantially constant level of material in said supply hopper whereby to effect a substantially uniform gravitational flow of material from said feeding means, said control means 4 including means for terminating the delivery of material thereto when the level thereof exceeds a predetermined maximum height, and for causing said delivery to be resumed when the material level falls below said maximum height, and means for terminating the operation of the load forming means when the level falls below a different and lower height.

8. A packaging machine having in. combination material feeding means for feeding material 6 by graity, a supply hopper located above and in direct communication with said feeding means and from which material is withdrawn, the rate at which material is fed by said feeding means being at least to some extent related to the head 61 of material in the supply hopper, means for delivering material to said supply hopper, and control means for maintaining a substantially constant amount of material in said supply hopper whereby to effect a substantially uniform 65 gravitational flow from said feeding means, said control means including means for supporting said hopper adapted to permit the latter to move vertically under the influence of the weight of the material in the hopper, means operatively 7C connected to said hopper for terminating the delivery of material thereto when the weight of the material in the hopper exceeds a predetermined amount and for initiating such delivery when said weight falls below said amount, and means for terminating operation of said feeding means when said weight falls below a predetermined but substantially less amount.

6 9. A packaging machine having in combination material feeding means for feeding material by gravity, a supply hopper located above and in direct communication with said feeding means and from which material is withdrawn, the rate at which material is fed by said feeding means being at least to some extent related to the head of material in the supply hopper, means for delivering material to said supply hopper, and control means for maintaining a substantially constant amount of material in said supply hopper whereby to effect a substantially uniform gravitational flow of material from said feeding means, said control means including means for supporting said hopper adapted to permit the latter to move vertically under the influence of the weight of the material in the hopper, a pair of limiting switches adapted to be operated by the vertical movement of said hopper for terminating the delivery of material thereto when the weight of the material therein exceeds a predetermined maximum and for terminating the operation of said feeding means when said weight falls below a predetermined minimum.

10. A packaging machine having in combination material feeding means, including a supply hopper provided with a conduit extended downwardly therefrom and through which material may flow by gravity from the hopper, means for delivering material to the supply hopper, and control means for .maintaining a substantially constant amount of material in said supply hopper whereby to effect a substantially uniform gravitational flow from said feeding means, said 0L control means including means for supporting said hopper adapted to permit the latter to move vertically under the influence of the weight of the material in the hopper, means operatively connected to said hopper for terminating the deliv65 ery of material thereto when the weight of the material in the hopper exceeds a predetermined amount and for initiating such delivery when said weight falls below said amount, and means for terminating operation of said feeding means when 0 said weight falls below a predetermined but substantially less amount.

11. A packaging machine having in combination material feeding means including a supply hopper provided with a conduit extended down5 wardly therefrom and through which material may flow by gravity from the hopper, means for delivering material to said supply hopper, and control means for maintaining a substantially constant amount of material in said supply hop3 per whereby to effect a substantially uniform gravitational flow of material from said feeding means, said control means including means for supporting said hopper adapted to permit the latter to move vertically under the influence of the 5 weight of the material in the hopper, a pair of limiting switches adapted to be operated by the vertical movement of said hopper for terminating the delivery of material thereto when the weight of the material therein exceeds a predetermfned maximum and for terminating the operation of said feeding means when said weight falls below a predetermined minimum.

ARTHUR W. LINDHOLM.

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