US2381505A

US2381505A - Packaging machine

Info

Publication number: US2381505A
Application number: US444624A
Authority: US
Inventors: Arthur W Lindholm
Original assignee: Pneumatic Scale Corp
Current assignee: Pneumatic Scale Corp
Priority date: 1940-04-04
Filing date: 1942-05-27
Publication date: 1945-08-07
Anticipated expiration: 1962-08-07

Description

FIP8Z1 EX REEERENCE XR 293819 505 1 v Aug. 1,1945.

EXAMWER 3 Sheets-$haet 1 ENCE EXAMIMH "250-201, CROS'SREEER I- A. W..LINDHOLM 2,381,505

- manque ucanm Original Filed April 4, 1940 3 Sheets-Sheet 2 Mill/Ill/l/l/l/l/l/l/l/l/l/l/l/I"Ag/ll 1 Ill/II In VENT-5Q can; 4r. AWL wk ww g 2 5-0 2 0 1 CROSS REEERENCE ER l- 1945 A. w. LINDHOLM 2,381,505

- PACKAGING ucnma Original Filedlpril 4, 1940 3 Sheets-Sheet a Patented Aug. 7, 1 945 PACKAGING MACHINE Arthur W. Lindhoim, Milton, Masa, assignor to Pneumatic Scale Corporation, Limited, Quincy, Masa, a corporation of Massachusetts Original application April 4, 1940, Serial No. 327,755. Divided and this application May 27.

1942, Serial No. 444,624

11 Claims.

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an object to provide a novel and improved packaging machine having a material supply hopper from which the material is withdrawn to be packaged and in which provision is made for maintaining a substantially constant level or material in the supply hopper including control mechanism for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 maxithe claims at the end of this specification. In

the drawings the invention has been illustrated as embodied 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. 5 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 The successive loads of material thus withdrawn may be formed in various known manners as by weighing or measuring.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 be n 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 weighins. the machine is provided with a material S pp y hopper II to which material is delivered by a conveyer I! from any suitable source of ,sup-

, D 17. and from which the material is withdrawn by suitable material feeding mechanism, inditonitrestingupononeendoiascalebeam general, the illustrated weighing machine may include an intermittently operated package moving mechanism including package pusher arms 20 mounted upon an endless chain 22 adapted to move a. carton onto the scale pan 2 of the scale beam it during one period of operation, and control mechanism, indicated generally at '26, adapted to open and close the shutters 2!, ll of the material feeding mechanism it during another period of operation. In the automatic weighing machine the cartons are supplied to the machine upon an inlet conveyer 32 and successive cartons are transferred onto a platform 34 into. the path of the pusher arms 20 by a transfer member 85. As fully described in the Howard patent above referred to, the machine is controlled to operate in successive cycles through connections actuated by the movement of the scale beam it whereby the shutters 28. are closed and the package moving cycle of operation is initiated when the scale makes its weight. Thereafter when the package moving cycle has been completed, the shutters 28, ID are again opened to permit the material to flow by gravity into afresh carton delivered onto the scale. The

- cated generally at ll, to be introduced into a carmaterial feeding mechanism It maybe provided with the usual stirrers it. 38 to facilitate the flow.of the material therethrough. As herein shown, the machine may be driven by an electric motor ll through its pulley 42 connected by a belt 45 to a drive pulley It on the machine. As will behereinafter described. the electric motor It forms part of a circuit arranged to be opened to stop the machine when the weight of the material in the supply hopper ialls below a predetermlned minimum amount.

From the description thus far, it will be observed that the material is withdrawn from the supply hopper it by the feeding mechanism It, the material falling by gravity through the bottom of the hopper as it is required by the feeding mechanism. In the embodimentof the invention, as illustrated in Fig. 1, the discharge end 4! of the hopper is loosely inserted into the top of the feeding mechanism, forming a telescopic con ered with relation to the feeding mechanism in accordance with the weight of the material in the hopper as will be described.

As illustrated in Fig. 1, one form of mechanism for conveying the material from its source and delivering it to the supply hopper may comprise .the conveyer l2 whichmay include a conduit ll having an inlet 82 and an outlet It and through which an endless conveying element It is arranged to run. The conveying element rims over an idler II at one end or the conduit and a driven sprocket it 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 I having a pinion .4 in mesh with a gear 5 fast on the sprocket shai't ll. The electric motor 62 forms part of a circuit arranged to be opened to stop the conveyer wh'en 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 sumcient to state that the conveying element It when moved through the conveyer casing operates to convey the material in a continuous stream from the inlet 2 to be discharged through the outlet 54.

As herein illustrated, see Fig. l, the material supply hopper ll may be supported upon compression springs II, coiled about, studs I2 extending from a platform II, the latter being supported by rods ll depending from the fioor above. The platform It is provided with an opening ll through which the lower portion of the hopper extends. The studs 12 are slidingly fitted through bearings It provided in a flanged portion 82 of the hopper III. Thus, the hopper is free to move vertically under the influence oi the weight of the material in the hopper.

Provision is made for controlling the operation of the supply conveyer I2 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 82 includes a switch ll having a stationary contact I! and a movable contact II, the latter being pivotally mounted in the switch supporting bracket 22 attached to the stationary platform II. The switch is normally held in its closed position as illustrated in Fig. 1, by a common spring 24 extended between the switch arm 96 and a similar switch arm 28 forming part of a similar switch I" included in a circuit "2 leading to the machine motor 40. A switch arm engaging stud Ill vertically and adJustably mounted in a bracket I" is secured to the side of the hopper It, and normally, when the hopper is filled with the normal amount oi material, the

I02 at contacts'lll, III, thereby stopping the machine motor ll. When the required amount of material has been delivered to the hopper by the conveyer I2,'the contacts I, III will be restud m is disposed between the two arms as, u I

without engaging either. In operation, it the hopper I0 is filled above a predetermined height, the additional weight or the material will cause the hopper to descend. The stud I will then engage the arm I. andopenthe circuit 84 at the contacts 88, to .thereby stopping the conveyer motor 62 and consequently stopping the delivery of the material to the hopper. During the operation oi the machine, continued withdrawals of material from the hopper will cause the hopper to rise under the influence of the springs II and the

contacts

88, 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 I2 fails to replenish the material withdrawn from the hopper, continued withdrawal or material will cause the hopper to become abnormally light, and when this occurs, the springs II will raise the hopper and the stud III! will engage the arm II and openthe circuit established to again start the weighing machine. Thus, a substantially constant level of material is maintained in the hopper ll through the use 0! the limiting switches 28, Ill operated by vertical movement of the hopper eflected by the relative weight or the material therein. The usual cutout switches H2, H4 may be provided in the circuits N, "2 respectively, in order to permit operation of the conveyer I2 or the weighing machine without going through the limiting switches, when such operation is necessary.

Referring now to Figs. 2 and 3, modified forms of the mechanism for delivering material to the supply hopper II -are herein illustrated. In Fig. 2, a vibratory feeder II is employed. Material is delivered through a funnel III from a source of supply onto the vibratory i'eeder which is operated through a vibratory motor I" to deliver the material into the hopper II. The vibratory motor I2. is provided with leads I22, I24 which may be included in the circuit 24 in p ace of the motor 62 in order to start and stop the vibration of the vibratory motor I20 in accordance with the amount of material in the hopper II, as above described, whereby the feed of the material into the hopper may be thus controlled.

Another modification oi the mechanism for delivering material to the supply hopper II, as illustrated in Fig. 3. may comprise a tunnel I2 through which the material may fiow by gravity irom the source of supply into the hopper II. As herein shown, the funnel I2 is provided with a gate or shutter I28 which may be operated by a solenoid I having leads I32, I which may be connected in the circuit 24, 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 mechanism may include a fixed supply hopper I" having light sensitive cells I42. I cooperating with light sources I, Ill respectively, mounted at diilerent levels in the hopper. The light sensitive elements are enclosed in casings Iil, I52 secured to the outside of the hopper and are provided with condensing lenses I, III secured to the inner wall of the hopper for concentrating the rays of light from the light sources onto the photo-electric cells. The light sources are likewise enclosed in suitable casings I", I and are protected from the material in the hopper by glass panels "2, I.

The hopper is provided with a cover I" and material may be delivered through an otiset opening I81 therein, as shown in Fig. 5. The material may be delivered by a conveyer I6! which may be driven by a motor ill, the latter being diagrammatically shown in the wiring circuit in Fig. 4. Power is supplied to the motor through the main leads I12, I14 through a solenoid operated switch I". When the material in the hopper rises above the level of the upper light sensitive cells I42 it will intercept the light ray from the source I and as a result, a relay mechanism which may be of any well-known type indicated at I18 becomes operative to actuate the solenoid I" to open the circuit to the conveyer motor I'll at the switch I'll to thereby terminate 2,ss1,sos

the delivery of material to the hopper. Continued withdrawals of material from the hop-' per will lower the level therein to again expose the photo-electric cell I 42 to the ray of light I46 whereupon the switch I15 will again be closed to start the conveyer I88.

The photo-electric cell I42 is'connected to the relay I18 by the leads I82, I. Leads I85, I" connect the main leads to the relay. The solenoid I80 is connected to the relay by leads I81, I89. The source of light I is supplied with current through the leads I00, I92. In operation, the relay I" is adapted to close the circuit within the relay to operate the solenoid Ill when the light ray to the photo-electric cell I4! is cut oil. 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 isv disposed in an offset position so thatthe incoming stream of material will not operate to cut 03 the light ray. On the other hand, should the material in the hopper become depleted below the level of the lower light sensitive cell I, to expose the cell to the ray of light from the source I, a relay mechanism It! will become operative to actuate a solenoid I96 to open the circuit to the machine motor II! at the switch 2". As herein shown, power is supplied to the motor I from the main leads I12, I14 and through leads 202, Ill. The connections to the relay I include the leads "8. 208 from the main leads, the leads III, 2I2, to the photo-electric cell I and the leads 2", ill to the solenoid I. The light source I is connected to the power supply through leads us, 2". Normally. when the light source is cut oil by the material in the hopper, the switch 200 will remain closed to drive the machine. However, when the photo-electric cell I is exposed to the light the relay III will operate to energize the solenoid I 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 In, I.

- 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 sbeam to the end that errors in weights which hav 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, flied April 4,

Having thus described the invention what is claimed is:

1. A packaging machine having in combination, material feeding means, a sup y 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 eii'ect 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 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 eifect 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 substantialiy less amount.

' 3. 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 fail 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 eflect 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 verticaliy 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 forming 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 successi loads of the material withdrawn from the su ly hopper through said conduit, and control means for maintaining a substantially constant level of material-in said supply hopper whereby to eflect a substantially uniform fravitational 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,

5. A packaging machine having in combine 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 latter becomesnlled in excess of apredetermined 75 gravity. means for forming successive loads of I 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 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 difl'erent 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 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.

8. A packaging machine having incombination 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 now 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 operativehr 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.

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 latterto 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 termihating 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 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 delivcry 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.

11. 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 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.

ARTHUR W. LINDHOLM.