US2758765A - Bag filling machine - Google Patents

Description

Filed Jan. 15, 1954 F. L. HOPKINS ETAL BAG FILLING MACHINE 4 Sheets-Sheet 1 II 4 II w= I I I I I I I I 6 I I I I I I l I I 3-2 z II Z9 IFIL 5 zz I I I 30 T I Z9 30 IN V EN TORS' ATZGP/Vffj 14, 1955 F. L. HOPKINS ET AL 2,758,765

BAG FILLING MACHINE Filed Jan. 13, 1954- 4 Sheets-Sheet 2 IN VEN TORS 4, 1956 F. L. HOPKINS ET AL 2,758,765

BAG FILLING MACHINE Filed Jan. 13, 1954 4 Sheets-Sheet 3 I 5a @3 4 I w in E [B v o a 5/ i IN VEN TORS 14, 1956 F. L. HOPKINS ET AL 2,758,765

BAG FILLING MACHINE Filed Jan. 13, 1954 4 Sheets-Sheet 4 ATTOF/VE/J United States Patent Ofiice Patented Aug. 14, 1956 BAG FILLING MACHINE Frank L. Hopkins and Leslie Steinberg, Minneapolis, Minn., assignors to Bemis Bro. Bag Co., St. Louis, Mo., a corporation of Missouri Application January 13, 1954, Serial No. 403,677

'10 Claims. (Cl. 226-59) Our invention relates generally to packaging machines and more particularly to improved devices for filling packages such as bags with granular or powdered material.

More particularly, our invention relates to improvements in bag feeding and filling machines of the type disclosed in the United States Letters Patent to Daniel Belcher et al. No. 2,343,879, granted March 14, 1944.

In the packing of certain granular or powdered materials such as sugar, flour or the like, weighed quantities of material are generally fed to a bag or container by gravity from a weighing hopper through suitable guide means such as a chute or the like. Such material fed in this manner enters the container in a more or less loose condition and requires that the container be jarred or jogged to cause the contents to settle for the most effective packaging thereof. An important object of our invention is therefore the provision of a package filling machine of the type set forth which will deliver material to be packaged to the container in a relatively tightly packed condition whereby to reduce the time consumed in properly settling the material in the container.

Another object of our invention is the provision of a delivery hopper and novel means for packing powdered or granular material in the hopper to a predetermined degree.

Another object of our invention is the provision of novel means for packing said material in the hopper substantially uniformly throughout its depth in the hopper.

A still further object of our invention is the provision of a plurality of movable material packing elements in tandem relationship in a delivery hopper and of novel continuously operated friction driving means for driving said elements whereby, when the material in the hopper has been packed to a predetermined degree, packing movement of said elements will automatically stop.

Still another object of our invention is the provision of a delivery hopper having a discharge opening and novel closure means for said discharge opening against which the material in the hopper is packed before the delivery thereof to a bag or like container, and of novel closure operating means responsive to the presence of a bag in a material receiving position adjacent the discharge opening in the hopper to move said closure away from the dis charge opening to permit delivery of material to the bag by the packing elements within said delivery hopper.

The above and still further highly important objects and advantages of our invention will become apparent from the following detailed specification, appended claims and attached drawings.

Referring to the drawings, which illustrate the invention, and in which like characters indicate like parts throughout the several views:

Fig. 1 is a view in front elevation of a bag filling machine built in accordance with our invention;

Fig. 2 is a view in side elevation of the machine of Fig. 1;

Fig. 3 is an enlarged fragmentary view partly in side elevation and partly in vertical section taken substantially on the line 33 of Fig. 1;

Fig. 4 is an enlarged fragmentary section taken substantially on the line 44 of Fig. 3; and

Fig. 5 is a diagram showing means for operating the closure means of our invention.

In the preferred embodiment of the invention illustrated, a feeding and bag filling machine is shown as comprising a supporting structure 1 comprising side frame members 2 and 3 and suitable bracing including upper and lower cross members 4 and 5 respectively. The supporting structure 1 mounts a pair of like bag filling mechanisms 6 which operate independently of each other but in like manner. The bag filling mechanisms 6 are identical in structure, hence but one thereof will be described in detail. Each of said mechanisms comprises a delivery hopper 7 which is generally circular in cross section and which has a discharge opening 8 at its lower end. Underlying each discharge opening 8 is a bag holding device which is indicated in its entirety at 9 and which supports an open bag in register with the discharge opening 8 of its respective hopper 7. The discharge hopper '7 is adapted to receive a predetermined quantity of powdered or granular material such as flour, sugar or the like by means of a delivery chute 10 from a weighing bucket 11 which forms a part of suitable weighing and dispensing mechanism 12 that is supported by a framework 13 mounted above the machine 1. Such weighing mechanism is clearly shown in the afore-mentioned Belcher et al., Patent 2,343,879. Material is delivered to the weighing bucket 11 from a suitable source such as a supply hopper or the like 14.

The bag supporting mechanism 9 includes a pair of depending blades or shoes 15 and 16 the latter of which is mounted on a shaft 17 for lateral swinging movements toward and away from the former. Such lateral swinging movements may be imparted to the shoe 16 by a reciprocatory pitman arm 18 pivotally connected at one end to a crank arm 19 which is mounted fast on the shaft 17. The shoes 15 and 16 are adapted to project downwardly into an opened bag 20 and frictionally hold the same in an open condition directly below the discharge opening 8 of the delivery hopper 7. A bag-actuated control switch 21 is mounted in a suitable supporting element 22 that is carried by an arm 23 pivotally secured at its upper end to the frame structure 1 as indicated at 24. The switch 21. includes an operating button or the like 25 which is in register with a recess 26 in the shoe 15, which recess is normally covered by a bag 20 when the same is held by the shoes 15 and 16. Thus, when a bag 20 is applied to the bag holding device 9, engagement of the bag by the switch button 25 causes closing of the switch 21 for a purpose which will hereinafter be described. The abovementioned bag holding mechanism and control switch is clearly shown and described in the copending Kindseth et al. application for United States patent filed July 13, l, S. N. 236,526, and entitled Bag Feeding and Filling Machines. Hence, for the sake of brevity, it is not deemed necessary to describe the bag holding mechanism 9 and switch 21 in greater detail.

Bags may be fed to the bag holding mechanism 9 manually if desired, or suitable bag feeding mechanism such as that shown in the Belcher et al. patent aboveidentified or the Kindseth et al. application aboveidentified.

When a filled bag 20 is released from engagement with the bag holding mechanism 9 it is adapted to drop downwardly by gravity to supporting elements 27 which lower the same downwardly onto a conveyor 28 which comprises a plurality of endless conveyor belts 29 running over suitable pulleys 30, see Fig. 1. The conveyor 28 is adapted to deliver filled bags to suitable bag closing and sealing mechanism not shown, or to suitable place of stora ge also not shown. The conveyor 28 as well as the bag supports 27, which lower the bags downwardly to the conveyor 28, in themselves form no part of the instant invention. Preferably however, the supporting members 27, before lowering filled bags from the bag holding devices 9 to the conveyor belts 29, impart a jogging action to the bags whereby to settle the contents thereof. One form of mechanism for raising and lowering the supporting members 27 is fully disclosed in the Kindseth application for United States Letters Patent filed July 12, 1952, S. N. 298,561, and entitled Bag Shaking Mechanism for Bag Filling and Conveying Machines, now Patent No. 2,712,406.

The delivery hopper 7 is frusto-conical in shape, the larger end thereof being at its top and provided with a circumferentially extended radially outwardly projecting flange 31 through which extend machine screws or the like 32 which anchor the delivery hopper 7 to a bracket 33 bolted or otherwise secured to the frame 1, see particularly Fig. 3, The lower delivery end of the chute terminates in an opening 34 in the bracket 33 directly above the open upper end of the delivery hopper 7. The discharge opening 8 at the lower end of the hopper 7 is defined by an annular restricter ring 35 that is riveted or otherwise rigidly secured to the lower end of the hopper 7.

A bracket 36 is rigidly secured to the lower end of the delivery hopper 7 and projects laterally outwardly therefrom. Said bracket 36 defines a guide channel 37 in which moves a gate-like closure element 38 toward and away from an operative position between the hopper 7 and the bag 20 and in a direction transversely of the hopper 7. In its operative position the gate 38 positively shuts off flow of material through the discharge opening 8 of the hopper 7. The closure element or gate 38 is provided at its outer end with an upstanding lug 39 to which is rigidly secured the outer end of apiston rod 40 extending axially from one end of a piston 41 mounted for reciprocatory movements in a fluid pressure cylinder 42 that is rigidly secured to the upstanding outer end portion 43 of the bracket 36. The bracket 36 is supported from the delivery hopper mounting bracket 32 by means of a pair of laterally spaced vertically extending nut-equipped studs 44.

For the purpose of packing or compressing material fed from the weighing bucket 11 to the delivery hopper 7 into a relatively compact mass prior to discharge of said material into the bag 20, I provide a compresser element 45 comprising a pair of compressor sections 46 and 47 in the nature of axially aligned angers. The lower auger 46 extends from the bottom of the hopper 7' upwardly a distance preferably less than one-half the total depth of the hopper 7, the upper auger 47 extending from the top of the auger 46 to the top of the hopper 7. Also preferably and as shown, a third auger flight section 48' is utilized in conjunction with the upper auger 47, said third auger section extending a relatively short distance downwardly from the top of the hopper 7. The lower compressor element or auger 46 is rigidly mounted on a sleeve 49 that is keyed or otherwise rigidly secured to the lower of a shaft 50 which extends axially through the hopper 7 and upwardly through a tubular portion 51 of the bracket 33. The upper compresser elements or augers 47 and 48 are welded or otherwise rigidly secured to the lower end portion of a sleeve 52 which is concentric with and which is telescopically received on the's'haft 50; As shown in Fig. 3, the sleeve 52 is journalled in the tubular portion 51 of the bracket 33 by means of antifriction bearings 53 at the upper end of the bracket 33' and a sleeve bearing 54 at the lower end portion of the bracket 33. and 48 are of such diameters that a relatively small clearanceexists between the peripheral edges of the outer sections and the inner wall surface of the delivery hopper As shown the outer sections 46, 47

4 7. The shaft 50 is rotatable with respect to the sleeve 52 and extends upwardly beyond the upper end of the sleeve 52, its upper end being journalled in antifriction bearings 55 mounted in the upper end of an inverted L-shaped bearing bracket or the like 56 which is bolted or otherwise rigidly secured to the upper end of the mounting bracket 33.

Means for imparting independent rotary movements to the lower and upper auger sections 46 and 47 respectively comprises a continuously rotating driving member in the nature of a pulley or sheave 57 journalled on the upper end of the sleeve 52 through the medium of antifriction bearings 58, and a pair of driven elements 59 and 60 the former of which is operatively coupled to the shaft 50 and the latter of which is operatively coupled to the sleeve 52. The pulley 57 is preferably of the doublegroove type and has running thereover a pair of endless V-belts 61 which also run over a double-groove pulley 62. mounted fast on the shaft 63 of an electric motor 64;

The driven element 59 comprises an annular flange 65 having mounted thereon an annular friction ring 66 which ope'ratively engages one side wall surface 67 of the drive pulley 57. The flange 65 is provided with a hub portion 68 which is axially slidably mounted on a bushing 69 which in turn is keyed to the upper end portion of the shaft 59 for common rotation therewith. A key 78 locks the flange 65 to the bushing 69 for common rotation therewith but permits axial sliding movement therebetween, whereas a set screw 71 locks the bushing 69 to the shaft 50 against relative axial movement between the bushing 69 and the shaft 50. An annular thrust plate 72 is axially slidably mounted on the hub 68 and has interposed therebetween and the flange 65 a plurality of circumferentially spaced coil compression springs 73. An adjusting ring 74 has screw threaded engagement with the threaded upper end 75 of the bushing 69 whereby the yielding bias of the springs '73 may be increased or decreased to vary the frictional pressure between the annular friction ring or shoe 66 and the adjacent side wall surface 67 of the driving pulley 57.

The construction of the driven element 66' is similar to that of the driven element 59 and comprises a flange 76 having an annular friction ring 77 thereon which has frictional driving engagement with the side wall surface 78 on the driving pulley '57 opposite the side wall 6'7 thereof. The flange 76 is provided with a hub 7 9 that is mounted for axial sliding movements on a bushing 80 and which is locked against relative rotation with respect thereto by means of a key or the like 81. The bushing 80 is keyed to the upper end portion of the sleeve 52 as indicated at 82 and a set screw or the like 83 is utilized to positively 'lock the bushing 80 against axial movement with respect to the sleeve 52. An annular thrust plate '84' is mounted for axial sliding movements on the hub 7-9 and has interposed therebetween and the flange 76 a plurality of circumferentially spaced coil compression springs 85, An adjusting ring 86 is screw threaded onto the. threaded outer end 87 of the bushing 80 and is adapted to be manipulated to. vary the bias of the springs and to cause consequent variation in the frictional .en' gagement between the friction ring 77 and the adjacent wall surfacev 78 .of the driving pulley 57.

With the above arrangement, it should be obvious that, when flour or other granular or pulverized material, indicated at X in Fig. 3, is introduced to the delivery hopper 7, such material will be moved by the 'augers to the bottom of the hopper 7 and packed against the gate 38 to an extent where slippage will occur between the driving.

pulley 57 and the driven element 59. At this point the lower auger 46 will stop rotating, and the upper augers 47 and 48 will continue to rotate until such time as the pressure of the material X causes slippage to occur between the driving pulley 57 and the driven element 60. It should be noted that the augers 46 and 47 are rotated at a fairly high rate of speed so that the pressure of the material within the hopper 7 is built up very rapidly to a point where rotation of the augers ceases. Opening of the gate 38 relieves the pressure within the delivery hopper 7 thus permitting immediate feeding rotation of the angers 46 and 47 to eject the material X into the underlying bag 20. Thus the material X, as it is delivered to the bag 20, remains in a relatively tightly packed state and subsequent jogging of the bag to settle the contents therein can be reduced to a minimum. In practice it has been found that the use of the above described structure has reduced such jogging time to approximately one-half of that required when the material is permitted to flow freely into the bag and without first compacting or compressing the material. As above indicated, the extent to which the material X in the hopper is condensed or compacted therein before discharge into the bag is determined by the amount of friction between the driving and driven elements 57 and 59-60 respectively.

As above stated the driving mechanism for the material compressing element 45 is in constant operation during the bag filling process. During this process empty bags 20 are fed in succession to the bag holding mechanism 9. If desired, the bags may be fed manually, but preferably the bags are fed automatically to the bag holding mechanism by suitable devices not shown. Such devices are disclosed in the Belcher et al. patent aboveidentified and the Kindseth et al. application also aboveidentified. The diagram of Fig. illustrates a preferred control arrangement for the operation of the closure element 38 whereby the bags 20 are filled in succession. In Fig. 5 a control circuit is shown as comprising a power lead 88 extending between opposite sides of a two-wire power line 89. The bag-engaging switch 21 is interposed in the lead 88 in series with a manually operated master control switch 90 a cam operated switch 91 and a solenoid coil 92. The switch 91 is operated by a cam 93 mounted on a shaft 94 for common rotation therewith. The shaft 94 may be assumed to be power driven and under continuous rotation. Energization of the solenoid 92 by simultaneous closing of the switches 21, 90 and 91 causes movement of a valve element 95 to a position within a valve housing 96 permitting fluid such as air under pressure to be introduced to a chamber 97 in one end of a reverse valve housing 98 whereby to cause movement of a valve spool 99 therein in one direction against bias of a coil compression spring 100. Air under pressure is supplied by a suitable pump 101 through a conduit 102 leading from the pump to the valve housing 96 and through a second conduit 103 leading from the valve body 96 to the chamber 97 in the reverse valve 98. A conduit 104 delivers air under pressure from the pump 101 to a port 105 in the intermediate portion of the reversing valve 98. Under movements of the spool 99 in opposite directions, the port 105 is alternately registrable with spaced ports 106 and 107 to which conduits 108 and 109 respectively are connected. As shown the conduits 108 and 109 lead to opposite ends of the cylinder 42. The reverse valve 98 is further provided with ports 110 and 111 leading to atmosphere, the arrangement is such, that, when the valve spool is moved to its position of Fig. 5 by introduction of air under pressure to the chamber 97 therein, air under pressure will be supplied to the inner end of the cylinder 42 through the conduits 104 and 109. Air exhausted from the outer end of the cylinder 42 will be delivered to atmosphere through the conduit 108 and the ports 106 and 110. De-energization of the solenoid 92 by opening of the cam-operated switch 91 will shut off air to the valve 96 through the conduit 102 but will permit exhaustion of the air in the chamber 97 through the conduit I03 and an exhaust port 112 in the valve 96. With the chamber 97 in communication with the exhaust port 112 the spring 100 moves the spool 99 upwardly to a point where the port 105 is in communication with the port 106 and the port 107 is in communication with the port 111 thereby causing air under pressure to be introduced to the outer end of the cylinder through the conduit 108 whereby to cause movements of the gate 38 to its operative hopper closing position.

With a bag 20 positioned on the bag holding mechanism 9, and the closure member or gate 38 in its operative position, a predetermined quantity of material X is delivered to the hopper 7 where it is immediately packed downwardly against the gate 38 by the auger sections 46 and 47 for a time interval which is determined by the speed of rotation of the cam 93. When the cam 93 has rotated a predetermined distance, the switch 91 will be closed. This closing of the switch 91 will cause the solenoid 92 to position its valve element so that the reversing valve 98 will cause introduction of air under pressure to the inner end of the cylinder 42 and subsequent opening movement to be imparted to the gate 38. As above indicated as soon as the gate 38 is moved to its open position the packed material X will be ejected from the hopper 7 by the auger sections 46 and 47 into the bag 20 and at a speed greater than that which is present under purely a gravity feed. When the filled bag is released from the bag holding mechanism 9 the switch 21 will again open thereby causing the gate 38 to be moved to its normally closed position. Obviously, if a bag 20 is not present on the bag holding mechanism 9, the gate 38 cannot open. In this event, when material is fed to the delivery hopper 7, the angers 46 and 47 will rotate until pressure of the material X in the hopper causes slippage to occur between the pulley 57 and the driven elements 59 and 60. Thus the material in the hopper will be packed to a predetermined extent regardless of the time interval between material discharging operations.

We have found that by the use of our novel mechanisms herein described, that bags fed to the machine in succession may be filled more satisfactorily and with greater rapidity than heretofore. Rotation of the auger sections within the hopper 7 tend to keep the interior of the hopper in a clean condition.

Our invention has been thoroughly tested and found to be completely satisfactory for the accomplishment of the objectives set forth; and while we have shown and described a preferred embodiment of our feeding and filling machine, it will be understood that the same is capable of modification without departure from the spirit and scope of the invention as defined in the claims.

What we claim is:

1. In a machine for filling containers with granular or powdered material, a hopper having a discharge opening, means for supporting an open container in register with the discharge opening, a closure element for said discharge opening, means for feeding a predetermined quantity of material to the hopper, a rotary compresser element in the hopper, and power operated mechanism including a slippage connection for rotating the compresser element in a direction to apply predetermined feeding pressure to the material in the hopper toward the discharge opening, whereby to pack said material against the closure element and to eject the packed material into said container upon removal of the closure element from the discharge opening.

2. The structure defined in claim 1 in which said compresser element comprises an anger extending longitudinally of the hopper and terminating adjacent the discharge opening.

3. The structure defined in claim 1 in which said slippage connection comprises a rotary driven member operatively coupled to the compresser element and a cooperating rotary driving member having frictional engagement with the driven member, and in further combination with means for varying the degree of frictional pressure of the driving member against said driven member.

4. In a machine for filling containers with granular or powdered material, a generally vertically extended crossisectionally.circular hopper havinga discharge opening in its lower end, means for supporting an opencontainer in register with the, discharge openlngna closure element for said discharge opening, means7for feeding 6. The structure defined in claim. 5' in which said angers are each'carried by adifierentorreofa' plurality of concentric-shafts exten'dingaxially'of the hopper, and

in'which said slippage connection"comp-risesa common driving elementjournalled ononeofsaidshafts" anda plurality of driven elements oneeach" operatively-'coupled' toeach of saidshafts for-c0mmon"rotationthere= with, each of said driven elements having fr'ictionalengagement-with-said common driving element.

7. The structure definedinclaim 6 in'-further"'comhi nation with meansforindependently varying 'the' degree" of frictional pressure between said com'mondriving'el'emerit andeach 'of' said driven elements:

8. In a machine for filling containers with granular or powdered'material, a generally verticallyextendedcross sectionally circular hopper having a discharge *opening in itslower'end, means for supporting an open containerin" register with' the discharge opening; a gate'movable toward" and away from an operative-position between said' discharge opening and the containerandnorm'ally' closing" said discharge opening, power operated meehanism'ineluding a fluid pressure operated cylinder and-piston operatively coupled to said gate to move the samexbetween itsoperative position and in..inoperative position away from said opening, means for feeding, a predetermined quantity of material to the hopper, a pairof'axially.

aligned feeding augers in said hopper, a pair of'concentric shafts extendingaxially ofthe-hopper and'eacli carryinga diiferent one of said augers,sand'pow'er operated'mechanism for imparting independent rotary, movement to. each .of saidaugers to'apply; predeterminedfeed ing pressure to the material'in the hopper in the direction offsaid'discharge.opening, whereby to pack thev material against said gate when said gate is in its operative position and to. eject said packed material'into said? container upon removal'of the gate from the discharge opening, said last-mentioned mechanism including. a pair of. driven elements one eachon one of said-shafts and a common driving element frictionally engaging said'idriven elements.

9. The structure defined in claim 8 in further. combi nation with control means for the gate operating; mechanism, said control means including, acontr'ol switch engageable by a containerv carried by the container supporting means and operative responsiveonly tothepresence of a container in the container. supporting meansto. cause movement of 'said'gate to its inoperative position.-

10. In a machinev for filling containers withgranular. or powderedmaterial, ahopper. having .a discharge opening,,means for supportingan open container in register with the discharge opening, a closure element for. said discharge. opening, means for feeding, a predetermined. quantity of material to the hoppena compresser element in said hopper, and power operated. means=for driving. saidcompresser element in'a direction to. packn-saidlma terial toward the. closure. element, said power. operated means including a device responsiveto accumulation ofi pressure of material. in. the. hopper. to: a. predetermineddegree tocause interruption of packing-movement. of.- the. compresser. element; opening. of said closure: element: causing-release of said pressure, whereby. to cause-material: feeding; movements to be imparted to'- said compressor? element ;to: fill the container;

References. Citedwintthe file: of thislpatent- UNITED STATES PATENTS 876,389 Nickolai Jan; 14; 1908 1,791,611 Borchcrt Feb: 10; 1931* 1,795,312 Mojonnier et' al.- .Mar.'.10,-.l9 -3'1 1,847,690 Hottmann ...Mar; 1, 1932

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