US3008530A - Apparatus for filling bags - Google Patents

Description

Nov. 14, 1961 E. JENSEN APPARATUS FOR FILLING BAGS 5 Sheets-Sheet 1 Filed April 10, 1957 g INVENTOR I, 6468 iZZAL ATTORN Yf Nov'. 14, 1961 E. JENSEN APPARATUS FOR FILLING BAGS 3 Sheets-Sheet 2 Filed April 10, 1957 FIG. 4

Nov. 14, 1961 E. JENSEN APPARATUS FOR FILLING BAGS 5 Sheets-Sheet 5 Filed April 10, 1957 ATT 3,008,530 APPARATUS FOR FILLING BAGS Ejler Jensen, Copenhagen-Valby, Denmark, assignor, by mesne assignments, to F. L. Smidth & Co., New York, N.Y., a corporation of Delaware Filed Apr. 10, .1957, Ser. No. 652,052 Claims priority, application Great Britain Apr. 16, 1956 6 Claims. (Cl. 177-78) This invention relates to apparatus for filling bags with a predetermined quantity of finely divided material in pulverulent' or granular form. More particularly, the invention isconcerned with a novel apparatus for the stated purpose, in which the material is supplied to valve bags under automatic control from a stationary source and the filling operation is started and the filled bags are released by cam-controlled means. The invention may be advantageously employed in the form of a machine having units for filling a plurality of bags simultaneously, since, in such a machine, the cams for the several units can be mounted on a common cam shaft, so that the opertaing cycles of all the units are of the same duration and can be maintained in the proper relation to one another.

At the present time, there are two forms of apparatus in general use for filling valve bags and, in both types of apparatus, the material in a tank is rendered fluent by air and'flows through a filling spout into the bag, which is suspended on the spout. The flow to each spout is controlled by a combined weighing and filling unit, which also serves to discharge the bag from the spout when it is full. In one of the forms of apparatus, the tank rotates, so that the operator remains in one place and mounts the empty bags on the spouts as they mOVe past him. While this type of apparatus has a large filling capacity, in that a single operator can tend as many as twelve spouts, it is expensive to manufacture and an apparatus of so large a capacity is not always required. In the other form of apparatus, the tank is stationary and the operator moves back and forth along a line of spouts to mount bags thereon as required. To enable one operator to tend as many spouts as possible and thus obtain maximum results from the apparatus, the operating cycles of the units should be of the same duration and inter-related. Heretofore, in such a machine, the operation of each unit has been controlled by the weighing mechanism in the unit through an electric relay system and these systems are complicated and require operator with special training.

The present invention is directed to the provision of an apparatus for filling bags, in which a stationary tank is used and supplies the material to a plurality of automatic weighing units, by which predetermined amounts of material are introduced into the bags. in an apparatus embodying the invention, each filling unit includes means for starting flow into a bag and means for releasing the filled bag from the filling spout and these separate means are controlled by respective cams with all the cams for the units of the machine mounted on a common shaft. As a result, the operating cycles of all the units are of the same duration and, by proper setting of the cams on the cam shaft, the cycles of the several units proceed out of phase, so that the operator can move along the line of spouts and mount bags on the spouts successively as required.

In apparatus of the type described, it has been found United States Patent that the bags can be most accurately filled when the 3,008,530 Patented Nov. 14, I961 form of apparatus embodying the invention, such twostage filling is carried out and cam-controlled means start the filling in each stage and determine the rate of filling in the second stage, while the end of each stage is brought about by meansresponsi-ve to the weight of the filled bag.

In filling apparatus including a stationary tank, it is common to provide a rotary stirring mechanism and the apparatus in the invention includes such stirring means driven synchronously with the cam shaft. The mechanism is so constructed and operated as not to restrict flow from the tank into any filling spout at the instant that such flow is permitted.

In the operation of the apparatus of the invention, filling starts automatically under cam control and, in some instances, an operator may be unable to place a bag on a spout before the cam means starts the supply of material to that spout. To avoid the discharge of material through a spout which does not carry a bag, the machine is provided with means responsive to the presence of a'bag on each spout and acting in the absence of a bag to prevent the mechanism permitting flow to the spout from functioning. 1

In the new-machine, the bag being filled in each unit is released from the spout of that unit by cam action at a particular point in the cycle of operation of the unit. It sometimes happens that, at the time when a bag should be released from its spout, the bag is not full. To insure that only full bags are released from their spouts, each unit of the machine includes a mechanism responsive to the mechanism controlling flow and preventing the release means from releasing a bag whenever the flowcontrol means permits flow.

For a better understanding of the invention, reference may be made to the accompanying drawings, in which FIG. 1 is a view in front elevation of one form of apparatus embodying the invention with parts omitted;

FIG. 2 is a sectional view of the machine on the line 2--2 of FIG.1;

FIG. 3 is a fragmentary vertical sectional view showing the flow control means on a larger scale than employed in FIG. 2 and in different relative positions;

FIG. 4 is a fragmentary sectional view on approximately the line 22 of FIG. 1 and showing the filling spout in a position to release a filled bag;

FIG. 5 is a fragmentary sectional view illustrating one of the cams; I

FIG. 6 is a fragmentary view similar to FIG. 2 and showing means for preventing flow in the absence ofa bag; and

FIG. 7 is a view similar to FIG. 2 of a modified form of the apparatus. v

The apparatus shown in' the drawings comprises a horizontal vessel or tank 10 with a plurality of weighing and filling units 11 disposed along the tank at a uniform spacing. Material to be introduced into the bags by the units is supplied in fluidized condition to the tank '10 from a source of supply, such as a silo, through a pipe 12. The material is maintained fluidized in the tank by air supplied to the interior of the tank through a porous wall 13 from an air chamber 14, to which'an air pipe 15 leads. The air is diffused into the material within the tank and the maintenance of the fluidized condition of the material is assisted by a stirring device, which'is madeup. ofpaddles 16 mounted radially on a central shaft '17 extending lengthwise through the tank. The shaft carries a set of paddles in each space between adjacent filling .units 11 and the ends of corresponding paddles of the sets are connected by rods 18 extending lengthwise through thetank. One end of the shaft extends out of the tank and carries a gear 19, by which the shaft is continuously rotated during the operation of the apparatus. Air'issuing'from the material in the tank may escape'through a"dis'charge'pipe"20.

Each filling unit 11 comprises a frame 21 connected to the lower ends of a pair of vertically movable rods 22. Near one end, the frame'has a tubular section 23 forming a vertical passage, into which extends the lower end of aflexible rubber pipe 24 depending from a fitting 25 attached to the wall of'tank to encircle an opening through the wall of the tank near the bottom thereof. A shaft 26 is mounted to extend transversely in frame 21 and a bell- crank having arms 27, 28 is pivotally mounted on the'shaft with the arms attached at their ends to a filling spout '29 with a discharge section 30 atone end.

The other end of the spout and the lower end of tubular 'forms a. continuation of the passage through the section.

The flow of material through pipe 24 to spout 29 is controlled by a roller 33 mounted between legs on a flanged head 34 on a rod 35. The rod is freely movable .in an opening in a housing 36 carried by a bracket 37 attached to the underside of the-wall of tank 10 and the rod is urged to move the roller toward the pipe by a spring 38 encircling the rod and bearing at one end against housing 36 and, at the other, against the flanged 'head 3.4. 'The fitting '25 carries an abutment 39 on the opposite side of pipe 24-from the roller and, when the roller is in the extreme left-hand position (FIG. 3), the roller collapses the pipe 24 against the abutment, so that no flow through the pipe can take place.

The movements of the roller of each unit are under the control of two mechanisms, one of which includes a cam 40 on a shaft 41 extending lengthwise ofthe machine and carrying at one end a gear .42, which meshes with gear 19, the gears being of such sizethat the shaft 41 is driven in synchronism with shaft 17 but at a different speed. The cam 40 has a relatively long high are 40a and a shorter arc 40b of less height, which lies between two dips 40c, 40d, respectively, at the ends of arc 40a. A lever 43 pivotally mounted onabracket attached to the .wall of tank 10 carries at oneend of one arm :a roller 44, which bears against the .surface'of cam 40, anda spring 45 connected to the other arm-of the'lever and to a fixed point acts on the lever to hold roller 44 in contact with the cam. -An arm 46 is pivotally mounted on the lower end of lever 43 and, .for this purpose, the arm is provided with a boss 47, which encircles a pin 48 carried by; lever 43. The bossis formed-with anabutment engageable by a projection 49 on .a rod .50 pivotally mounted on a pin 51 at the end of rod 35 remote from roller 33. So long as lever '46.is prevented from counterclockwise movement relative to lever 43, the engagement of the projection 49 on rod 50 with the abutment, on

boss 47 is effective to prevent endwise movement of the rod. When cam-40 is so disposed as to permit ,roller 44 to move from arcs 40a-or 40b toward shaft 41, lever 43 may swing clockwise and'the rods 50 and 35 may move to the left as .shown in FIG. 3, so that'roller33 acts on pipe 24=to reduce or'stop' theflow of material through that pipe.

A latch 52'is pivotally,mounted on'the lower-endof arm 46 and its upper endnormally engages a pin 53 on the arm. The lower end,of-the latch:is:engageable with anadjustable stop:screwr,54 on :a-bracket 55 attached to frame 21 and, -when:the frame is in :the :normalyupper position, as shownin FIGS. '2 and 3,:the stop-screw lies .to theright of the lower endofllatch52. The spring 38 acting on rods35 and-50' tends to move them tothe left, so-that roller '33=willcollapse pipe 24 and cut off flow therethrough, andthe engagementof projection 49 ton-rod '50 with the abutment on boss 47 tends to-swing :arm 46 counter-clockwise. Such' movement of the arm beam.

'52 with'stop'screw'54 when'the frame is up, but, when the frame moves down, so that the abutment 54 is free of latch 52, rods 35 and 50 can move to the left, so that the roller cuts off flow through pipe 24 regardless of the position of lever 43 as determined by cam 40.

The frame 21 ispart of a Weighing mechanism and the rods 22 attached to the frame are pivotally mounted at one end of a weighing beam 56 ('FIG..2), which is supported on a knife edge bearing 57 on a bracket 58 extending upward 'from the top of the tank wall. A weight 59 attached to the other end of the beam counterbalances the frame 21 and its associated parts, so that the weight and frame are in balance in the absence of a bag on the end section 30 of the filling spout 29. Atthe lower end of Weight 59, there is a hook 60 for supporting an additional weight 61 corresponding to the desired gross weight of each filled bag.

As previously pointed out, it is advantageous to fill each bag in two stages with the main feed in the first stage occurring at a rapid rate and a dribble flow into the bag taking place in the second stage. In the apparatus of the invention, the frame 21-moves downwardly when the bag is nearly filled and such downward movement releases latch 52, so that rods 35 and 50 can be moved by spring 38to cause the roller 33 to cut off the flow.

Thereafter, the frame 21 is caused to rise, so that latch 52 is re-engaged with stop 54. At the same time, cam 40 acts through arm 43 and rods 50 and 35 to cause the roller to permitflow at a reduced rate through pipe 24. The

frame 21 moves downwardly again to cut off flow, when the desired weight of material'has enteredthe bag, and thereafter release of the filled bag occurs.

In order-to carry out the operations described, each unit of the machine is provided with a lever 62 pivotally mounted on bracket 58 and pivotally connected at one end to a rod 63 carrying a weight 64 corresponding to the weight of materiaLto be introduced into a bag by dribble flow. Rod63 extends through a bracket 65 connected to rods '22 and has a flange 66, which may rest upon the bracket. The other end of lever 62 carries a roller 67 engageable with a cam 68 on shaft 41. Cam 68 has a long are 68a of relatively small radius, a shorter arc 68b of larger radius, and a projection 68c of still larger radius atthe trailing end of arc68b. When frame 2 1 is in its upper position and bracket 65 has engaged flange 66 on rod 63 and moved the rod upward to swing lever 62 clockwise, the roller 67 is opposite to but out of contact with the arc 68a onpthe cam. 1 Under such conditions, the weight 64 acts on frame 21 and on the end of. beam 56 in opposition to weights 59 and 61 acting on the other end of the Inthat situation, frame 21 willmove downward when the weight of the bag and its contents plus weight -64 just'exceeds weight 61, that is, when the weight of the bag and contents just exceeds the weight to be introduced into the bag at the high rate.

A pawl 69 is pivoted at one end on a shaft 70 carried by a frame 21 and the other endof the pawl has a recess for receiving a roller 71 carried at the end of an arm 72 attached to the bell-crank 27, 28. When the. roller is seated in the recess, the filling spout is prevented from counter' clockwise movement. The pawl has a lug 69a, which is engageable by-a hook at the lower end of rod 63. When roller 67 on arm 62 is in contact with are 68b of cam 68, arm 62 is swung clockwise to raise rod 63 sufficiently to move the flange 66 out of engagement with bracket 65 attached'to arms 22. Under such conditions, the weight 64 is without effect and, while roller 67 is in contact with arc'68b, the filling of the bag is being completed at the reduced rate. When the projection'68c engages roller 67 on arm 62, the arm is swung so that the hook'63a engages the lug 69a on pawl 69 and the pawl is raised clear of the roller 71 on arm 72. When this occurs, the filling spout 29 is swung counterclockwise by the weight of the filled bag thereon to the position shown in'FIG. 4 and remains in that position, until the bag slides off the end section 30 of the spout, whereupon the spout is swung back to its initial position by weight 32.

In order to hold a bag on section 30 of the spout during the filling operation, a bell-crank 73 is pivotally mounted on a shaft 74 carried by frame 21. A pad 75 is adjustably mounted on one arm of the bell-crank and the other arm carries a screw 76 engageable with a cross-bar 77 on frame 21 and adjustable to vary the angular position of the bell-crank on shaft 74. When the spout 29 is in normal position with its upper curved end in engagement with the curved surface at the bottom of the tubular section 23 on frame 21, the pad 75 rests in contact with the upper surface of end section 30 of spout 29 and acts with a wedging action to clamp a bag telescoped over section 30 tight ly in place on the latter.

Because of inertia, the flow of material into a bag does not stop the moment the beam 56 reaches a balanced condition and it is, therefore, desirable that the frame 21 start to move downward a little ahead of the time when flow is to be cut off at the end of each stage. For this purpose, a small weight 78 is mounted on an extension of one rod 22. As the weight acts against weights 59 and 61, it tends to cause flow to stop before the desired amount of material has been introduced into a bag in either stage. The size of weight 78 is determined experimentally, so that it counteracts the inertia effect.

It is desirable to enable the operator to cut off flow of material to the filling spout of any unit, if he has not had time to place a bag upon the spout before the flow is about to start. For this purpose, a lever 79 is pivotally mounted in bracket 37 and has an end extending forwardly, so that it is accessible at the front of the machine. The other end of the lever lies beneath rod 50, and, by rocking the lever, the rod can be swung to free its projection 49 from the abutment on boss 47 on arm 46. As soon as the projection is disengaged from the abutment, the spring 38 can move rods 35 and 50, so that roller 33 collapses the tube 24 and cuts off flow.

In the operation of the apparatus, the operator telescopes a valve bag over the end section 30 of the filling spout 29 at a time when the upper end of the spout is held against the lower end of tubular section 23 of frame 21 by counter-weight 32 and flow through pipe 24 is cut off by roller 33 clamping the pipe against abutment 39 under the pressure of spring 38. At this time, the frame 21 is in its upper position with stop 54 in the path of latch 52 on arm 46 and roller 44 on arm 43 rising out of dip 40d on cam 40. The are 68a on cam 68 lies opposite roller 67 on lever 62 and, since frame 21 is in the up position, the bracket 65 on the frame engaging flange 66 on rod 63 has caused the rod to rise and swing arm 62, so that its roller 67 is out of contact with are 68a. As the bag is telescoped over the end section 30 of the spout, it passm beneath the pad 75 on bell-crank 73 and is clamped tightly in position. When the roller 44 has moved out of dip 40d on cam 40 and reaches arc 40a, lever 43 is swung counter-clockwise and, in this movement, the abutment on boss 47 on arm 46 acts on the projection 49 on rod 50 to move rods 50 and 35 to the right (FIG. 2) against the action of spring 38, so that roller 33 wholly releases pipe 24 and fiow at full speed throught the pipe commences. As the lever 43 moves counter-clockwise, the engagement of latch 52 with pin 53 on arm 46 and with stop 54 results in a clockwise movement of arm 46 relative to lever 43. As a result, the abutment on boss 47 is effective to act on the projection and cause the endwise movement of the rods. The discharge of material from the tank through pipe24 and the filling spout 29 into the bag now proceeds at a high speed, until the bag has received the quantity to be introduced in the first stage. At this point, the frame 21 moves down under the weight of the bag, so that stop 54 disengages the lower end of latch 52. The arm 46 can then swing counter-clockwise and the spring 38 acts on head 34 on rod 35 to move that rod and 6 rod 50 to the left (-FIG. 2), so that the roller 33 closes tube 24 and cuts off flow. In such movement of the rods, the projection 49 on rod 50 in engagement with the abutment on boss 47 on the arm 46 swings the arm counterclockwise.

Just after the flow of material in the first stage is terminated as described, the arc 68b on cam 68 moves into engagement with roller 67 on arm 62 and this causes the arm to swing clockwise, so as to raise rod 63 and disengage its flange 66 from the bracket 65 on arms 22 connected to frame 21. This renders the weight 64 on rod 63 ineffective and the weights 59 and 61 cause the beam 56 to swing and the frame 21 to rise. As the frame starts to rise, the dip 40c on cam 40 moves beneath the roller 44 on lever 43 and this permits the spring 45 to move the lever, so that the lower end of latch 52 on arm 46 will lie to the left of stop 54, when the frame 21 is in its up position, and the arm will be held against counter-clockwise movement relative to lever 43. Just after the frame 21 reaches the end of its up ward movement, the arc 40b on cam 40 moves into engagement with roller 44 and this causes lever 43 to be swung counter-clockwise. In such movement, arm 46 moves with lever 43 and the abutment on the boss 47 on the arm acts on the projection 49 on rod 50 and causes rods 50 and 35 to be retracted against the action of spring 38. As the radius of are 40!) on cam 40 is less than the radius of arc 40a, the movement of lever 43 by are 40a effects only a partial retraction of roller 33 from pipe 24, so that the pipe is only partly opened and flow through the pipe takes place at a reduced rate.

Flow at the lower rate through pipe 24 continues until the weight of the bag and contents equals weight 61 less the small weight 78, whereupon the beam 56 swings and frame 21 again moves down. As soon as such downward movement starts, the stop 54 moves away from the end of latch 52 and spring 38 moves rods 35, 50 to cause the roller 33 to cut off flow. Directly thereafter, the projection 680 on cam 68 swings lever 62 to raise pawl 69 and release arm 72 attached to bell-crank 27, 28. The filling spout 29 then swings counter-clockwise under the weight of the bag to a position, in which the end section 30 is free of the pad 75 on bell-crank 73. The bag is then free to slide off the filling spout. As soon as this occurs, the frame 21 starts to rise and, as it does so, roller 44 enters dip 40d in cam 40 causing lever 43 to be swung clockwise, so that the latch 52 on arm 46 carried by the lever lies to the left of stop 54. Such movement of arm 43 permits spring 38 to hold rods 35, 50 to cause roller 33 to cut off fiow through pipe 24 and, while the flow is thus stopped, the operator mounts another bag on the end section of the filling spout. As roller 44 rides out of dip 40d and upon arc 40a, lever 43 is moved to retract rods 35 and 50 and cause the roller 33 to disengage tube 24, so that flow therethrough at the maximum rate is permitted. Immediately after projection 68c has passed out of contact with roller 67, the roller lies opposite the arc 68a on the cam and, in this stage, the lever 62 occupies a position such that weight 64 is acting on frame 21 against weights 59, 61. When the roller 44 starts its movement along arc 40a of cam 40, a filling cycle has been completed and the cycle is repeated throughout the operation of the machine.

The modified construction in FIG. 6 avoids the necessity of manual manipulation of the lever 79 to shut off flow when no bag has been placed on the filling spout following the release of the filled bag. In the modified construction, a bell-crank lever 80 is pivotally mounted on bracket 37 and has one end adapted to engage rod 50 and swing it upward, so that the projection on the rod will be released'from the abutment on the boss 47 on arm 46 and the rod can be moved to the left by spring 38 to cause roller 33 to shut off flow through tube 24. The other arm of the bell-crank 80 carries a plate 81 lying opposed to one end of a rod 82, which is movable in a bracket 83attached to frame 21 and has its other end pivotally attached to one end of a lever 84 pivoted on the frame. The other arm of lever 84 carries a weight 85 tending to swing the lever clockwise and the end of this arm carries a roller 86 engageable with a bag mounted on the filling spout. When a bag is in position on the spout, it swings lever 84, so that rod 82 is retracted and bell-crank 80 is without effect on rod 50. When no bag is on the spout, lever 84 swings to move rod 82 and the rod causes bell-crank 80 to swing to raise rod 50 and free its projection from the abutment on'the boss 47 on arm 46. The spring 38 can then move rod 50 and rod 35 attached thereto to cause roller 33 to close pipe 24 and cut off flow therethrough.

In the operation of the apparatus, the cam 68 of each unit releases the bag from the filling spout of that unit at a particular time in each filling cycle and, if the pipe 24 should become clogged or the supply of material should give out while a filling operation is proceeding, the bag being filled might not contain the correct weight at the time the cam functions to release the bag. To avoid suchan occurrence, features shown in FIG. 7 illustrating a modified apparatus may be employed.

In the FIG. 7 construction, the rod 63 is replaced by a rod 87 having a section 88 pivotally mounted at its lower end and having a hook 88a at its lower end and a bend 88b above the hook. An extension 89 is attached to rod 35 to project beyond abutment 39 and an arm 90 is connected to the extension and is provided at its free end with a lug 90a. Whenever a bag is completely filled and frame 21 moves down, the rod 35 is moved by spring 38, so that the roller 33 clamps tube 24 and stops flow therethrough. In such movement of rod 35, the arm 90 is moved to the left, so that its lug 90a is out of the path of travel of the bend 88b on the end section 88 of rod 87. Accordingly, when the projection 680 on cam 68 engages the roller 67 on the end of arm 62 and moves that arm clockwise, the hook 88a on the end section 88 of arm 87 can engage the lug 69a on pawl 69 and raise the pawl to permit the filling spout 29 to swing clockwise and release the bag. If, however, the bag is not filled and arm 35 has not been moved to the left by spring 38, the lug 90a on arm 90 will lie in the line of movement of the bend 88b on the section 88 of arm 87. Accordingly, when projection 680 on cam 68 acts to cause lever 62 to swing clockwise and raise arm 87, the bend 88b on the end section of arm 87 will engage lug 90a onex-tension 90 and arm 87 will be swung laterally by engagement with the lug, so that the hook 88a on section 88 will pass by lug 69a on pawl 69 and the pawl will not be rocked to free the filling spout. The bag will, accordingly, remain on the spout and its presence will indicate to the operator that it has not been properly filled.

It will be understood from the foregoing that the cam 40 controls the fiow of material from the tank to the filling spout through the valve made up of pipe 24 and roller 33 and cyclically varies the adjustment of the valve. When the high arc 40a of the cam is on operative position in. relation to the roller 44 on lever 43, the roller 33-is retracted, so that the flow'at the maximum rate through tube 24 can take place. When the roller 44 on arm 43 enters dip 40c, roller 33 shuts off flow through tube 24 entirely and when roller 44 is on the low arc 40b of the cam,.roller 24 permits flow at a reduced rate through tube 24. When roller 44 is in dip 40d in the cam, flow through tube 24 is again wholly cut off" by roller 33. If the apparatus were-constructed for single stage filling, cam 40 would have only a high are corresponding to 40a and a singlevdip correspondingto one of the dips 40c, 40d.

The effectiveness of cam 40 in varying the adjustment of the flow valve 24, '33 depends on the connection of lever 43 to rod 50. This connection is made through the abutment on boss 47 on arm 46 and the projection 49 on the rod and the connection functions effectively only when rod 50 is in its down position and arm 46 is held against counter-clockwise movement relative to lever 43 by engagement of latch 52 on the arm with stop 54 carried by bracket 55 attached to frame 21. When the frame moves down under load to release latch 52, cam 40 is no longer effective to determine the adjustment of the flow valve and, similarly, the effectiveness of the cam in determining the valve setting is destroyed, when rod 50 is raised, as by lever 79, to raise its projection 49 from boss 47 on arm 46.

The cam 68 controls the release of the bag from the filling spout by controlling the means which hold the spout in place and prevent it from swinging under the weight of the loaded bag. Cam 68 also performs the secondary function of controlling the effectiveness of weight 64, which acts in cooperation with the partially loaded bag to terminate the first stage of filling. By rendering weight 64 inoperative at the proper time in the cycle, cam 68 makes it possible for weights 59, 61 to raise the frame 21, so that the second stage of filling can be initiated by the low arc 40b on cam 40. If the machine were constructed to fill bags in a single stage, the arc 68b would be omitted from cam 68 and the cam would have only projection 68c acting once per cycle to raise rod 63 and make pawl 69 inoperative to hold the spout against swinging under the weight of the loaded bag.

It will be understood that the manual means for cutting off flow and the means for the same purpose responsive to the absence of a bag on the filling spout, which are shown in FIGS. 2 and 6, respectively, are used alternatively. The means shown in FIG. 7 for preventing discharge of a partly filled bag may be used with either the manual or automatic flow cut-offs, as desired.

I claim:

1. An apparatus for filling a bag with finely divided material, which comprises a weighing beam, a frame supported by one arm of the beam for vertical movement, a spout mounted on the frame and adapted to enter a bag, the spout being movable between a position in which it is capable of supporting a bag and a position in which it is inoperative to support a bag, means for holding the spout in bag-supporting position, counterweighing means acting on the beam and urging it to hold the frame in an upper position, means for supplying material to the spout, including a valve having a movable element adjustable to vary the rate of feed of the material through the spout to a bag thereon and biased toward closed position, cam-actuated means operating to hold the valve alternately in full open and partially open positions to provide a rapid main feed and a slower dribble feed, means operable by the descent of the frame to disable the valve-holding means, the valve thereupon closing, and a second cam-actuated means operating in timed relation to the valve holding means to increase the effectiveness of the counterweighing means at the end of a main feed to cause the frame to rise and re-activate the valve holding means, the second cam-actuated means acting at the end of a dribble feed to disable the spout-holding means, a connection between the movable element of the valve and the valve holding means, and means on the frame operable'when the frame is up to render the connection operative and to disable the connection when the frame is down, said connection between the valve-holding means and the movable element of the valve including a lever, a latch mounted on the lever, and a stop on the frame engageable by the latch when the frame is up to make the latch operative to hold the lever in effective position, the removal of the stop from contact with the latch on descent of the frame making the latch and lever inoperative and disabling the connection.

2. The apparatus of claim 1, in which the cam of the valve-holding means is constructed to swing the lever.

9 when the frame rises, to place the latch in operative relation to the stop and establish the operativeness of the connection.

3. The apparatus of claim 1, in which the spout lies at the front of the apparatus, the connection between the valve-adjusting means and the movable element of the valve lies at the rear of the apparatus, and means are provided for permanently disabling the connection, said means including a member acting on part of the connection and extending to the front of the apparatus.

4. An apparatus for filling a plurality of bags with finely divided material, which comprises a vessel elongated horizontally and having a plurality of bottom discharge openings spaced along it, a valve controlling flow through each opening, a weighing beam disposed above the vessel at each opening, a filling spout at each opening for supporting a bag and directing into it material issuing through the opening, means for connecting each spout to depend from one arm of the beam above the opening, at which the spout lies, the spout being movable relative to the connecting means between positions, in which it is operative and inoperative, respectively, to support a bag, means for holding each spout in bag-supporting position, counterweighting means acting on each beam and urging it to hold its spout in an upper position, means for adjusting each valve to increase and decrease its opening in accordance with a cycle, each valve-adjusting means including a cam, means operable by the descent of each beam for rendering inoperative the means for adjusting the valve controlling flow through the opening below the beam, and means operating cyclically to render each spout-holding means inoperative, the cyclically operating means including a cam, a single shaft extending lengthwise of the vessel and carrying the cams of all the valve-adjusting means and of all the means rendering the spout-holding means inoperative, and means for rotating the shaft.

5. The apparatus of claim 4, in which the pairs of cams at the respective openings are mounted in such different angular positions on the shaft that the cycles of operation at the openings are out of phase.

6. The apparatus of claim 5, which includes a shaft within the vessel, stirring means on the shaft, said means including elements movable past the openings adjacent thereto, and means for connecting the shaft to the cam shaft, the connecting means causing the shaft within the vessel to rotate in such relation to the cam shaft that said elements are remote fro-m each opening, through which material is being discharged.

References Cited in the file of this patent UNITED STATES PATENTS 1,078,971 Thomas Nov. 18, 1913 1,634,538 Fegely July 5, 1927 1,713,023 Bushman et al May 14, 1929 1,739,061 Cleaves Dec. 10, 1929 1,903,188 Middelboe Mar. 28, 1933 2,009,408 Middelboe July 30, 1935 2,039,257 Middelboe Apr. 28, 1936 2,101,232 Augustin Dec. 7, 1937 2,770,439 Stafford et al Nov. 13, 1956

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