US2561306A - Gripper for the tops of bags, sacks, and the like - Google Patents

Description

y 17, 19.51 I H. ANDERSON 2,561,306

GRIPPER FOR THE TOPS OF BAGS, SACKS AND THE LIKE Filed April 10, 1947 2 Sheets-Sheet 1 I l C9 28 ?E o m 2 8 I l8 2 l2 IL )3 54 80 I4. I 76 58 11 o o [H a 44 o o a 52 INVENTOR HELMER ANDERSON BY W ATTY

July 17, 1951 GRIPPER FOR THE TOPS OF BAGS,

Filed April 10, 1947 H. ANDERSON SACKS AND THE LIKE 2 Sheets-Sheet 2 HELMER ANDERSON Patented July T7, 1951 GRIPPER FOR THE TOPS OF BAGS, SACKS, AND THE LIKE Helmer Anderson, Minneapolis, Minn., assignor to General Mills, Inc., a corporation of Delaware Original application May 13, 1943, Serial No. 486,918. Divided and this application April 10, 1947, Serial No. 740,689

This invention relates to grippers for holding sheets by their upper edges, such as the open tops of bags, sacks, and the like.

An object of this invention is the provision of means for readily gripping the open opposite top sides of the sack or bag, particularly paper bags, preferably at the center so as to hold the same suspended vertically.

Another object is to provide gripping means which will increase the grip due tothe weight of the bag and contents.

Still another object is the provision of gripping members which are eccentrically mounted with respect to each other so that a straight downward pull on the sheet gripped tends to move the gripping members toward each other thereby bringing them closer together and increasing the grip on the object.

These, and other objects as will hereinafter appear, are accomplished by this invention which is fully described in the following specification and shown in the accompanying drawings, in which Figure 1 is a partial side elevation showing the top of a machine embodying this invention;

Fig. 2 is an end elevation of the same;

Fig. 3 is a partial enlarged vertical elevation of the bag grippers showing the gripper plates in process of gripping a bag but not locked at the entering end of the machine; and

Fig. 4 is the same with the gripper plates locked and about to be released at the head end of the machine.

This is a division of my copending application, Serial No. 486,918, filed May 13, 1943, entitled, Compacting Flour in Bags, now Patent No. 2,419,330.

The embodiment herein illustrated comprises four vertical corner posts or standards I I, I2, I3, and I4 which are secured at the bottom to a base not shown and at the top to a top casting I5.

A carriage I5 is slidably mounted at these four corners on the four vertical posts and may be raised and lowered thereon by means of four screw-threaded shafts I8 which are threaded through suitable blocks 20 on the sides of the carriage and are journalled in bosses 22 inthe sides of the top casting I5. These shafts are provided at their tops with bevel gears 24 which mesh with bevel gears 26 on shafts 28 which are connected by suitable similar sprockets 30 which in turn are connected by a chain 3 I. One of the shafts 28 is provided with a crank handle 32 as shown in Fig. 2. By turning this the carriage I6 may be raised and lowered as desired with a parallel motion. I

11 Claims. (Cl. 248-99) A motor M is preferably mounted on the top casting I5 and has a belt for driving the mechanism as shown in the original application of which this is a division. It is not necessary, however, that this drive be shown herein as it forms no part of the present invention.

A head shaft 49 (Fig. 1) is suitably journalled in bearings 42 in the carriage I5 and carries a bevel gear 44 which is driven by a bevel gear 46.

The latter is an integral part of a sleeve 48 which I is journalled in a vertical bearing 50 and which is internally splined to receive a splined shaft 52 which is driven in any suitable manner. While the shaft 52 rotates, it has substantially no endwise movement, whereas the sleeve 48 and. bevel gear 46 move up and down with the carriage I6. Motion is thus transmitted to the head shaft 49 and this shaft drives spaced sprockets 54 in a counterclockwise direction and which in turn drive the spaced chains 56 which pass around the tail sprockets 58 which are mounted on a suitable shaft 60, the tension in the chain 56 being adjusted by means of adjusting screws 92.

Flights I0 are carried on the chains 56 as shown particularly in Figs. 3 and 4, and each flight is provided with two laterally extending rollers 12 at each end which are journalled on suitable pins I4. These rollers roll on parallel tracks I6 above and I8 beneath, which in turn are carried on suitable brackets 89, 82 respectively from the carriage I6.

Plain gripper jaws 95, 96 are carried by levers 91, 98 which in turn are carried on shafts 99, I00 suitably journalled in the flight Ill. On similar shafts IOI, I92 are mounted other levers on which are carried corrugated gripper jaws I03, I04. The jaw I93 is pivotally mounted at I95 on a bell-crank I06 which in turn is pivotally mounted at I91. The opposite end of the bell-crank is pivotally connected to a short eyebolt I08 which passes through a lever I09 and is adjustably secured by means of lock nuts IID. This eyebolt is normally pressed inwardly by means of a compression spring III. The pin I9! is carried on the lower end of a lever IIZ which is rotatably mounted on the shaft IUI and carries a shoulder H3 against which the upper end of the corrugated gripper jaw I03 is slidable and suitably guided. The upper end of the lever H2 is pivotally connected to a link II4 by means of a pin I I5. The opposite end of the link I I *4 is pivotally connected to the upper end of the lever 98 by means of a pin I I6.

The levers 91 and I I2 are caused to oscillate in opposite directions by means of meshing seg- H mental gears. The upper end of'the corrugated gripper jaw I03 is held against the shoulder II3 by means of a spring Ill. The levers 98 and H2 are normally urged in a clockwise direction by means of a tension spring I I8.

The link H4 is hollow and has an adjustable locking block II9 mounted therein and adjustably secured by means of bolts I20. This block has a shoulder I2I which is adapted to be engaged by the outer end of a locking finger I22 mounted on a shaft I23 which is suitably journalled in the flight 10 and which carries a release lever I24.

The operation of this intermittent feed bag gripper is as follows. With the jaws 95, 9B. and I03, I04 separated, as shown in- Fig. 2, the bag or object to be gripped is raised as shown in dotted lines in Fig. 1 in which position the top of the bag comes between open operating pairs of gripping jaws at the two sides of the bag. A latching lever I30, whose construction and operation will later be described, presses the link II4 to the left thereby rocking the levers 91 and H2 toward each other and moving the locking jaws into adjacent position as shown in Fig. 3. A further movement of the link I I will cause the gripping jaw I03 to slide down with respect to the jaw- 95, as shown in Fig. 4, thereby causing an ear I25 to slide down over the inclined upper portion I25 of the jaw Q5, thereby firmly locking together the jaws st and Iiit. A further movement of the link IM under pressure of the lever I30 will cause the bell-crank I05 to rock in a clockwise direction about the pin I? thereby lowering the jaw I03 with respect to the jaw 95 as shown in Fig. 4. At the same time the shoulder I2I passes beyond the locking finger I22 which lifts into position behind the shoulder I2I by the action of spring mm which is attached to the end of a depending arm on the lever I24, thereby locking the parts of the gripper in gripping position. At the same time the lever 08 moves to grip the top: of the bag between the grippers 9B and H34 in the same way and by a similar system of levers which are largely duplicate parts and hence have not been described in detail.

The weight or" the bag serves to further tighten the hold of the grippers on the bag. Thisis accomplished by making the jaws slidable with respect to each other and by roughening or corrugating the inner surface of the outer or movable jaw W3 while the inner surface of the jaw 95 is smooth. The movable jaw will tend to move with the paper. Thus, the jaw I 03 is pivotally mounted on thebell-crank Iiitwhich swings about the pin [37. Any downward movement of" the jaw I03, as shown by the difierence in positions of the jaws 95 and I03 in Figs. 3 and l results in a toggle action of the bell-crank Hi8 which brings a much greater pressure between the jaws 9:: and I03. The inside of the jaw is made smooth to prevent damage to the inner liner of multi-wall bags which are often of much thinner material than the outer Walls of the bag. The corrugations on the jaw Hi3 are not sharp enough to cut or tear the outer walls.

The mechanism for locking and unlocking the grippers is fully described inmy original application Ser. No. 486,918 and will not be duplicated herein. It consists primarily of a lever I30: (Fig. 3) which forces the locking block H9 to the left when the latter reaches a predetermined point in its travel thereby closing. the pairs of gripper jaws 05; I63 and 06, I0 1 on has top or other object placed between. them. The gripper. jaws are firstopen wide as shown in Fig. 2 andas- 4 the flight I0 comes beneath the center line of the tail sprockets 58 the lever I30 forces the gripping jaws nearly closed as shown in Fig. 3 and then into the fully closed position of Fig. 4 wherein the lockingfinger I22 is held on the shoulder I2 I.

the flight approaches the head end of the machine a lever I60 strikes the release lever I24 releasing the finger I22 while the spring II8 of Fig. 4 returns the gripper jaws to the open position shown in Fig. 2. This releases any bag or other object held by the grippers.

While the foregoing description and drawings apply particularly to gripping the opposite top edges of bags, it is apparent this gripper is not necessarily limited to this particular application.

Thus, it will be seen I have provided a simple but efficient means for gripping the open top of a bag or other flat object held between the grippers.

While I have shown and described but. a single embodiment of my invention, it is to be understood that it is capable of many modifications Changes, therefore, may be made which do not depart from the spirit and scope of my invention as disclosed in the appended claims.

I claim:

1. In mechanism of the class. described, means for gripping and suspending a bag by its top comprising pairs of gripper jaws, the inner jaws being smooth and the outer jawsv roughened tomore firmly grip the bag, the jaws of each pair being pivotally mounted so that the jaws approach each other as the outer jaw moves down.

with respect to the inner jaw whereby the weight of the bag tends to cause said jaws to more firmly grip the bag.

2. In mechanism of the class described, means for gripping and suspending a bag by its top comprising pairs of gripper jaws, the inner jaws being smooth and the outer jaws being roughened, the outer jaw being provided with an overhanging ear adapted to engage an inclined upper portion of the inner jaw, the jaws of each pair being pivotally mounted with respect to each. other so that the weight of the bag tends to cause the outer roughened jaw to slide down with respect to the. other so that the overhanging lip engages the inclined upper portion of the inner jaw to provide a wedging action to increase the grip: of the. jaws on the bag.

3. In. mechanism of. the class described, means for gripping and suspending a bag by its top comprising pairs of gripper jaws, the inner jaws being smooth and. the outer jaws being roughened, the outer jaw being provided with an overhang,- ing ear adapted to engage an inclined upper portion of the inner jaw, the jaws of each pair being pivotally mounted with respect to each other so that the weight of. the bag tends to cause theouter roughened jaw to slide down with respect to the other so that the overhanging lipengages the inclined upper portion of the inner jaw to provide a wedging action to increase the grip of the jaws on the bag, the jaws of each pair being, pivotally mounted so that the jaws approach each. other as the outer jaw moves down with respect to the inner jaw whereby the weight of the bag tends to cause saidjaws to more firmly grip the bag.

4. In mechanism of the class described, means; for gripping and suspending a fiat object by itstop comprising a frame, a primary lever pivotally.- mountedthereon and having at its lower end afirst gripping jaw, a. secondary lever pivotally mounted eccentrically to the primary lever. and-- hingedly carrying a gripping jaw, the two levers being geared to oscillate in opposite directions to open and close the gripping jaws, and means operably connected to the primary lever for locking the same in a position to grip a flat object between the gripping jaws.

5. In mechanism of the class described, means for gripping and suspending a flat object by its top comprising a frame, a primary lever pivotally mounted thereon and having at its lower end a first gripping jaw, a secondary lever pivotally mounted eccentrically to the primary lever and hingedly carrying a bell-crank at its elbow, the lower leg of the bell-crank being pivotally connected to a second gripping jaw, the upper leg of the bell-crank being pressed by a spring that tends to urge the second gripping jaw toward the first gripping jaw, the two levers being geared to oscillate in opposite directions to open and close the gripping jaws, and means operably connected to the primary lever for locking the same in a position to grip a flat object between the gripping jaws.

6. In mechanism of the class described, means for gripping and suspending a fiat object by its top comprising a frame, a primary lever pivotally mounted thereon and having at its lower end a first gripping jaw, a secondary lever pivotally mounted eccentrically to the primary lever and hingedly carrying a bell-crank at its elbow, the lower leg of the bell-crank being pivotally connected to a second gripping jaw, the upper leg of the bell-crank being pressed by a spring that tends to urge the second gripping jaw toward the first gripping jaw, the two levers being geared to oscillate in opposite directions to open and close the gripping jaws, and means operably connected to the primary lever for locking the same in a position to grip a flat object between the gripping jaws, the first jaw being smooth while the second jaw is roughened so that downward movement of the object gripped between the jaws moves the bell-crank and second jaw downward relatively to the first jaw to cause a greater grip between the jaws.

7. In mechanism of the class described, means for gripping and suspending a flat object by its top comprising a frame, a primary lever pivotally mounted thereon and having at its lower end a first gripping jaw, a secondary lever pivotally mounted eccentrically to the primary lever and hingedly carrying a bell-crank at its elbow, the lower leg of the bell-crank being pivotally connected to a second gripping jaw, the upper leg of the bell-crank being pressed by a spring that tends to urge the jaws toward each other, means on said jaws tending to urge the upper end of the second gripping jaw toward the first gripping jaw, the two levers being geared to oscillate in opposite directions to open and close the gripping jaws, and means operably connected to the primary lever for locking the same in a position to grip a flat object between the gripping jaws.

8. In a mechanism of the class described, means for gripping and suspending a bag by its top comprising a pair of gripper jaws, one jaw pivoted below the point of gripping contact so that as the jaw moves downwardly it will approach the opposing jaw, thereby more tightly gripping the bag as the bag moves downwardly.

9. A mechanism of the class described, means for gripping and suspending a flat object by its top comprising a frame, means mounted thereon carrying a first gripping jaw with a gripping face, carrying means mounted on the frame and being movable from a non-gripping to a gripping position, a jaw carrying member pivotally connected to said carrying means, a second gripping jaw having a gripping face abutting said first jaw face in gripping position, said second jaw hingedly connected to the jaw carrying member to permit self-alignment of the jaw faces in gripping position, and spring means urging the jaw carrying member to pivot in a direction to move the second gripping jaw toward the first.

10. In a mechanism of the class described, means for gripping and suspending a bag by its top comprising a first and second jaw with opposing gripping faces, the first jaw having an upper inclined surface opposite the face and being fixed when in gripping position, a pivotal carrying member connected to the lower portion of the second jaw and pivoted to cause movement of said lower portion toward the first jaw when the jaw moves downwardly while in gripping position, and an overhanging ear carried by the upper edge of the second jaw adapted to engage the inclined upper surface of the first jaw to provide a wedging action to increase the grip of the jaws on the bag as the second jaw moves downwardly with respect to the first.

11. A mechanism of the class described, means for gripping and suspending a flat object by its top comprising a frame, means mounted thereon carrying a first gripping jaw with a flat gripping face, a second gripping jaw having a fiat gripping face, and jaw carrying means mounted on the frame and movable to carry said second jaw from non-gripping position to gripping position against said first jaw, the sec; ond jaw being hingedly connected to said jaw carrying means at a point intermediate opposing edges of the gripping face to permit selfalignment of the faces of the first and second jaws in gripping position.

HELMER ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 141,186 Thomas July 22, 1873 440,073 Tryon Nov. 4, 1890 1,019,366 Sargent Mar. 5, 1912 2,332,002 Neuman Oct. 19, 1943

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