US3645301A

US3645301A - Bag venting device for valve bag filling machines

Info

Publication number: US3645301A
Application number: US80568A
Authority: US
Inventors: Erwin M Lau
Original assignee: Black Products Co
Current assignee: Amcor Flexibles North America Inc
Priority date: 1970-10-14
Filing date: 1970-10-14
Publication date: 1972-02-29
Anticipated expiration: 1989-02-28
Also published as: GB1356053A; CA940496A

Abstract

A pair of fingers are located immediately below the spout. They are mounted on a vertically sliding yoke, which has side rails engaging in grooves formed in vertical guides. The guides are mounted on the plate which supports the spout, one guide on each side of the spout. An air cylinder pushes the yoke down so that the fingers will engage the valve opening of a bag suspended from the spout and stretch the opening to permit air to escape from the bag. The fingers when extended also clamp the bag to the spout.

Description

United States Patent Lau [ 1 Feb. 29, 1972 BAG VENTING DEVICE FOR VALVE BAG FILLING MACHINES Erwin M. Lau, Bolton, 111.

Black Products Co., Chicago, 111.

Oct. 14, 1970 Inventor:

Assignee:

Filed:

Appl. No.:

U.S.Cl. ..l4l/68, 141/93, 141/310, 141/314 Int. Cl. ..B65b 3/10, B65b 3/ 17 Field of Search 141/10, 50, 52, 67, 68, 93, 141/114, 285-310, 311-317, 390

References Cited UNITED STATES PATENTS Andreas ..141/310 Andreas ..141/3 10 Primary Examiner-Houston 8. Bell, Jr. Attorney-label Baker York and Jones [57] ABSTRACT A pair of fingers are located immediately below the spout. They are mounted on a vertically sliding yoke, which has side rails engaging in grooves formed in vertical guides. The guides are mounted on the plate which supports the spout, one guide on each side of the spout. An air cylinder pushes the yoke down so that the fingers will engage the valve opening of a bag suspended from the spout and stretch the opening to permit air to escape from the bag. The fingers when extended also clamp the bag to the spout.

7 Claims, 6 Drawing Figures PATENTEDFEB 29 I972 SHEET 1 BF 2 IN VEN TOR ERWIN M. LAU W ATT'YS.

PATENTEDFEBZS I972 SHEET 2 BF 2 IN VEN TOR ERWIN M. LAU egfl /w ATTYS.

BAG VENTING DEVICE FOR VALVE BAG FILLING MACHINES material, such as plastic, it is necessary to vent the bag in order to permit the filling air to escape.

The means for causing the material to be packed to flow horizontally from the chamber in the bag filling machine through the spout and into the bag requires the use of considerable amounts of air. In the case of powders and certain flaky and granular materials, the material is fluidized to cause this horizontal movement. With other granular materials, including pellets, fluidizing may not be necessary because the a pressure in the chamber is effective to move the material horizontally through the spout. In some cases an air jet located in the chamber, close to the outlet, is used to set the material in motion. In all of these flow imparting arrangements, there is considerable amount of filling air which passes through the spout with the material and which must be removed from the bag.

It has previously been proposed to use a double spout, the annular space between the inner and outer spout sewing as .a vent passageway.

In the case of granular materials, the particle size of which approaches the width dimension of the annular space, the particles may be blown into the vent passageway and become jammed therein.

Other disadvantages of the double spout arrangement are that the overall diameter of same is so large with respect to the 4 valve opening of the bag as to impede rapid bag placement on the spout, and no matter how large the overall diameter, the inner filling tube will be of a smaller diameter, the inner filling tube will be of a smaller diameter than the outer diameter of a more rapid filling and looser fitting single spout.

According to my invention, I provide a pair of fingers which lie adjacent a single spout of a diameter such that the valve opening of the bag can be fitted over the same very rapidly. Then, after the bag is in place, the fingers are shifted away from the spout to stretch the valve opening downwardly to provide a space or vent passageway beneath the spout through which the filling air can be vented.

The space or vent passageway is of generally rectangular cross section of substantial dimension; if any material particles should become lodged therein, they would drop to the floor upon removal of the bag.

By providing an actuator, such as an air cylinder which puts a definite loading on the fingers, the venting mechanism also serves as a bag clamp. Thus my invention provides a single mechanism which both vents the bag and holds it in place on the spout. In order to develop the proper clamping force, I mount the finger assembly in guides so that the fingers will remain parallel to the spout axis when in extended position. Thus the clamping action is distributed uniformly along the length of the flap or sleeve of the valve opening.

Other objects, features, and advantages of my invention will become apparent as the description proceeds. In the drawings:

FIG. 1 isa side elevation of a portion of a bag filling machine embodying my invention;

FIG. 2 is an enlarged side elevation view of the bag venting means shown in FIG. 1 taken along line 2-2 of FIG. 4;

FIG. 3 is a front-view of FIG. 2;

FIG. 4 is a plan view of FIG. 2 along line 4-4 of FIG. 2 with certain parts omitted for the sake of clarity, and the spout being shown only in broken lines;

FIG. 5 is an enlarged detail plan view of the finger means; and

FIG. 6 is a vertical section taken alongline 6-6 of FIG. 5.

With reference now to FIG. 1, the bag filling machine comprises the machine framework 10 which supports a chamber 11 adapted to receive the material to be fed into the bags. A bag supporting spout l2 communicates with the lower end of the chamber 11 and is mounted at the upper end of a spout supporting frame 13. The spout supporting frame may also serve as a support for other equipment not shown, such as a 7 bag saddle.

The spout supporting frame 13 is connected at 130 to suitable scale mechanism 14, such as that shown in my eopending application, Ser. No. 799,356, filed Feb. I4, 1969, now US. Pat. No. 3,540,539 Since the spout supporting frame 13 has relative vertical movement with respect to the machine framework 10, a flexible connection is provided between the spout I2 and the chamber 11 in the form of a rubber tube 15.

A valve-type bag 16 is slipped over the spout 12 to receive 1 material located in the chamber 11.

Means are provided to cause material to flow horizontally through the tube 15 and spout 12 into the bag 16. Such means are shown by way of example in FIG. I as a fluidizing pad 17 located in the lower part of the chamber 1 I, and connected to a filling air supply pipe 18, but it is understood that other means such as an air jet or air pressure applied to the top of the chamber may be substituted.

A spout valve in the form of an air actuated pinch valve 19 engages the rubber tube 15 to cut off the flow of fluidized material through the spout when the contents of the bag reach a predetermined weight, such as pounds.

The spout supporting frame 13 includes a spout mounting plate 20 having a collar 21 which surrounds the spout 12. The spout 12 extends through the opening provided by the collar and is centered in the opening by spacers 22.

Bracket 23 extends upwardly from the spout mounting plate 20 and carries an air cylinder 24 thereon. Vertical guides 25 extend forwardly from the plate 20, as shown in FIG. 4.

My invention provides finger means 26 which extend forwardly from the plate 20 and which is adapted to be received with the valve opening 27 of the bag 16 along within the spout 12 when the bag is placed on the spout. The construction of the valve opening varies with different types of bags, but generally it is either a flap or a separate sleeve which is designed to flatten out as the bag fills up and is removed from the spout so as to provide a closure for the opening. For the purpose of illustrating the operation of my invention, the separate sleeve type of valve opening is shown herein, which appears as a dot and dash line rectangle in FIG. 2.

Finger mounting means in the form of a yoke 28 is located between the guides 25 and confined to vertical movement thereby. In the normal position, the finger means 26 are located adjacent the spout 12 to facilitate entry within the valve opening 27 of the bag. The air cylinder 24 has a piston 1 rod 29 the lower end of which is secured to the top of the yoke 28. When the air cylinder 24 is operated, the yoke 28 and the finger means 26 are moved downwardly into the dotted line position shown in FIGS. 2 and 3, so that the valve opening 27 is stretched into its open position to permit venting of air from the bag as hereinafter described.

The yoke 28 also includes side rails 30 which are engaged by grooves 31 in the guides 25. Each side rail 30 has an inwardly extending horizontal arm 32 for supporting the finger means 26. As shown in FIG. 4, the finger means is a U-shaped structure made of rod stock having two legs 33 and a connecting portion 34. The arms 32 at their inner ends provide a half round concave edge which receives the inner end of each of the legs 33, which are welded thereto, thus providing a rigid mounting for the finer means 26.

The valve opening 27 is placed over the spout l2 and the finger means 26 whet latter is in its solid line position, as shown in FIGS. 2 and 3. A stop plate 41 mounted at the lower end of the yoke 28 defines the proper position of the bag on the spout. valve opening pinch valve removed from As soon as the bag filling cycle is initiated by the opening of the pinch valve 19, the control means governing the air supply to the pinch valve also supplies air to the connection 35 at the top of the air cylinder 14 to actuate same into the lowered dotted line position shown in FIGS. 2 and 3. Thus a space 36 is provided in the lower part of the valve opening 27, the space being defined by the lower surface of the spout 12 and the legs 33 of the finger means 26. The filling air is vented through this space 36. Then at the conclusion of the bag filling cycle, as determined by the tripping of the scale means 14, the pinch valve 19 is closed, and actuating air is supplied to the lower connection 37 of the cylinder to elevate the piston rod and the finger means 26 back to the normal position. This permits the bag to be removed from the spout l2.

The throw of the piston 29 is greater than the vertical dimension of the space 36 so that the size of the valve opening 27 determines the extent of the downward movement of the finger means 26. Thus the force applied to the piston, which may be of the order of 100 to 150 pounds, is, in turn, applied to the sleeve forming the bag opening 27. This force, if uniformly distributed along the length of the sleeve 27 is sufficient to hold the bag in position on the spout without tearing the sleeve or other part of the valve opening 27. The reaction of the sleeve on the finger means would ordinarily develop a torque on the piston rod and finger assembly which would tilt same and concentrate the clamping for at the front edge of the valve opening 27, and possibly tear same. In the construction shown, this is avoided by the sliding engagement between the side rails 30 of the yoke and the groove 31 of the guides which takes up the torque and maintains parallelism between the finger legs 33 and the spout axis in all positions. To summarize the foregoing, the air pressure provides a definite loading on v the fingers which not only stretches the valve opening but also clamps the bag on the spout, eliminating the need for a separate bag clamp. Then, as the material flows through the spout and into the bag, the filling air flows out through the space or passageway 36, and through the collar 21 into a dust collector 42 (FIG. 1) located on the framework just behind the collar 21. I

At the conclusion of the bag filling operation, when the pinch valve 19 is closed, there will be a certain amount of material contained within the spout, and some of this drops off into the bag 16.

Due to the concavity of the lower edge 40 of the spout as projected on a horizontal plane, the amount of this dribble will vary from time to time in a random manner when packing granular materials and pellets.

I have found that a greater uniformity in the amount of dribble which occurs can be maintained if the connecting portion 34 of the finger means serves as a partial barrier or dam at the end of the spout 12. Thus the material within the spout will tend to seek an angle of repose with respect to the top of the dam, as indicated by the dotted line 38 in FIG. 6. To this end, the connecting portion 33 of the finger means 26 is partially slabbed as shown at 39 in FIGS. 5 and 6 to closely overlie the lower edge 40.

lclaim:

I. In a bag filling machine having a chamber, a horizontally extending bag filling spout adapted to receive the valve opening of a valve bag, said spout being connected with the lower part of said chamber, means for supplying filling air to said chamber to cause material in the lower part of said chamber to flow horizontally through said spout and into a bag suspended therefrom, spout valve means for controlling the flow of material through said spout, and mounting means for said spout, the combination of horizontal finger means extending forwardly from said spout mounting means, means mounting said finger means for vertical movement between a first position located adjacent said spout and a second position in which said finger means is spaced away from said spout, and actuating means operative, when a bag is positioned on said spout and said spout valve means is opened, to move said finger means from said first position into said second position in which said finger means engage the valve opening of said bag and stretch same to permit said filling air entrained in the material flowing through said spout to escape from said bag through the space between the surface of said spout and said finger means.

2. A bag filling machine as claimed in claim I which includes fluidizing means located in the lower part of said chamber and connected to said fillin air supply means.

3. Bag venting means for a bag illmg machine having a chamber, a horizontally extending bag filling spout adapted to receive the valve opening of a valve bag, said spout being connected with said chamber, means for causing material in said chamber to fiow horizontally through said spout and into a bag suspended therefrom, means for controlling the flow of material through said spout, and mounting means for. said spout, comprising guide means on said spout mounting means, yoke means slidably mounted in said guide means, horizontally disposed finger means mounted on said yoke means and extending forwardly therefrom beneath said spout, and actuating means operative, when a bag is positioned on said spout, to move said yoke from a normal position in which said finger means are adjacent said s ut to downwardly displaced position in which said finger means engage the valve opening of said bag and tension same to provide a passageway through which said bag may be vented.

4. Bag venting means as claimed in claim 3 in which said finger means comprises two horizontally disposed rod like finger elements.

5. Bag venting means as claimed in claim 4 in which said rod like finger elements comprise the legs of a U-shaped member, the connecting portion of which is horizontally disposed and when in normal position overlies the lower edge of the open end of said spout to provide a dam therefor.

6. Bag venting means for a bag filling machine having a chamber, a horizontally extending bag filling spout adapted to receive the valve opening of a valve bag, said spout being connected with the lower part of said chamber, means for causing material in the lower part of said chamber to flow horizontally through said spout and into a bag suspended therefrom, spout valve means for controlling the flow of material through said spout, and a mounting plate for said spout, comprising guide means on said spout mounting plate providing oppositely disposed grooves, yoke means slidably mounted in said grooves, a pair of horizontally disposed fingers mounted on said yoke means and extending forwardly therefrom beneath said spout, and pneumatic actuating means operative, when a bag is positioned on said spout and said spout valve means is opened, to move said yoke from a normal position in which said fingers are adjacent said spout to a downwardly displaced position in which said fingers engage the valve opening of said bag and tension same to provide beneath said spout a passageway through which said bag may be vented, said tension causing said bag opening to engage the upper surface of said spout with a force sufficient to maintain said bag in position on said spout until said tension is relieved.

7. Bag venting means as claimed in claim 6 in which said spout mounting plate includes a collar at least partially surrounding said spout and spaced therefrom, spacer means between said spout and said collar, and dust collector means located behind said collar so that the air vented from said bag will flow through said collar and into said dust collector means.

Claims

1. In a bag filling machine having a chamber, a horizontally extending bag filling spout adapted to receive the valve opening of a valve bag, said spout being connected with the lower part of said chamber, means for supplying filling air to said chamber to cause material in the lower part of said chamber to flow horizontally through said spout and into a bag suspended therefrom, spout valve means for controlling the flow of material through said spout, and mounting means for said spout, the combination of horizontal finger means extending forwardly from said spout mounting means, means mounting said finger means for vertical movement between a first position located adjacent said spout and a second position in which said finger means is spaced away from said spout, and actuating means operative, when a bag is positioned on said spout and said spout valve means is opened, to move said finger means from said first position into said second position in which said finger means engage the valve opening of said bag and stretch same to permit said filling air entrained in the material flowing through said spout to escape from said bag through the space between the surface of said spout and said finger means.

2. A bag filling machine as claimed in claim 1 which includes fluidizing means located in the lower part of said chamber and connected to said filling air supply means.

3. Bag venting means for a bag filling machine having a chamber, a horizontally extending bag filling spout adapted to receive the valve opening of a valve bag, said spout being connected with said chamber, means for causing material in said chamber to flow horizontally through said spout and into a bag suspended therefrom, means for controlling the flow of material through said spout, and mounting means for said spout, comprising guide means on said spout mounting means, yoke means slidably mounted in said guide means, horizontally disposed finger means mounted on said yoke means and extending forwardly therefrom beneath said spout, and actuating means operative, when a bag is positioned on said spout, to move said yoke from a normal position in which said finger means are adjacent said spout to downwardly displaced position in which said finger means engage the valve opening of said bag and tension same to provide a passageway through which said bag may be vented.