GB2075473A

GB2075473A - Feeding sacks or bags

Info

Publication number: GB2075473A
Application number: GB8113780A
Authority: GB
Original assignee: DRG UK Ltd
Current assignee: DRG UK Ltd
Priority date: 1980-05-06
Filing date: 1981-05-06
Publication date: 1981-11-18
Also published as: GB2075473B

Abstract

Sacks, tubes or sack lengths (22, 22') are removed sequentially from the top of a stack (11) horizontally in a direction generally at right angles to their length with the aid of suction heads (17). In the initial stage of movement from the top of the stack there is at least a major component of movement in the direction of the length of the sack, tube or sack length (22, 22') produced by the circular movement of the crossbar (25) supporting the suction heads. The arrangement avoids rolling over of the plies of the top sack during removal from the stack (11). <IMAGE>

Description

SPECIFICATION Feeding sacks or bags This invention relates to a method and apparatus for the purpose of feeding paper or plastic sacks or bags, (referred to hereinafter for convenience as sacks), one by one from the top of a stack of sacks, and for similarly feeding tubes or sack lengths during the manufacture of sacks.

Considerable difficulty has been encountered when attempting to feed sacks, tubes or sack lengths horizontally in their own plane in a direction at right angles to their major dimension (length) such as is required, for example, when feeding sack lengths to a machine for forming a stitched end closure across one end of the length.

The difficulty arises from the fact that the friction beneath the underneath of the top sack length and the top of the next sack length below tends to be sufficiently great that when a horizontal force is applied to the top of the top sack length the sack -length perfqrms a rolling motion with the ply or plies on the top side of the sack length sliding over the ply our plies on the underneath side of the sack length. This effect is pronounced when the sack, tube or sack length has longitudinal side gussets.

It is an object of the present invention to provide an improved method and apparatus for feeding sacks, tubes or sack lengths in which the above difficulty is effectively overcome.

The present invention consists in a method of feeding sacks, tubes or sack lengths one by one from the top of a stack horizontally in a direction generally at right angles to their length, wherein in the initial stage of movement from the top of the stack there is at least a major component of movement in the direction of the length of the sack, tube or sack length.

The invention further consists in apparatus for feeding sacks, tubes or sack lengths one by one from the top of a stack horizontally in a direction generally at right angles to their length, wherein means are provided for applying force in a horizontal direction to the uppermost sack, tube or sack length of the stack such that in the initial stages of movement from the top of the stack there is at least a major component of movement in the direction of the length of the sack, tube or sack length.

In the accompanying drawings: Figure 1 is a diagrammatic plan view of one form of apparatus for carrying out the present invention; and Figure 2 is a diagrammatic section taken a line 2-2 of Figure 1 apparatus of Figure 1.

In carrying the invention into effect, the invention will be described by way of example with reference to the feeding of sack lengths, one by one, from the top of a stack 11 of sack lengths to pairs of horizontal conveyors 12 and 13 for feeding the sack lengths at right angles to the direction of their length onto a stitcher table 14 having a stitching machine (not shown) for providing a sewn end closure at the end of each sack length.

The stack 11 of such lengths rests upon a pneumatic elevator 1 5 having height control so that the top sack length is always at the level of the entry level to conveyors 12 and 13. Further stacks such as stack 11' are delivered when required by conveyor 16, and are fed to the bottom of the stack 11 so that a continuous supply of sacks can be delivered to the stitcher without gaps.

Mounted above the stack 11 are two suction heads 1 7 carried on a crossbar 25 pivotally connected by arms 1 8 to fixed supports (not shown). The crossbar 25 is rotated in a circular orbit by means of a motor 1 9 having a cranked arm 20 pivotally connected to the crossbar 25.

Rotation of the crossbar 25 causes the heads 17 to perform circular orbits of which are shown at 17. Raising and lowering of the suction heads 17 at the appropriate moments is effected by means of solenoids 26.

In operation, a sack length at the top of the stack 11 is initially in the position shown as 22 in Figure 1. The suction heads are lowered onto this sack length when in the positions shown as 1 7 so as to engage the sack near one of the longitudinal margins and, after suction has been applied, arm 20 is rotated to cause the heads to move to the positions shown as 17" and the sack length to be transported to the position shown as 22'.

The suction heads 1 7 can be designed so that as soon as they are attached by suction to the top surface of the top sack they move upwards slightly to lift the sack edge slightly.

It will be appreciated that as the sack length starts to move, it first travels in the direction of its length and this has been found to facilitate separation from the sack length next below by avoiding the rolling motion described above.

Thereafter the suction on one sack length is released and the conveyors 12 and 1 3 feed the sack length with the leading edge 23 of the sack length aligned with the datum line 24 for the stitching machine. The heads 1 7 continue orbiting in a circle until they reach position 1 7 again ready for the next sack length.

It will be appreciated that various alternative motions may be applied to the uppermost sack length provided that in the initial stages of movement from the top of the stack there is at least a major component of movement in the direction of its length.

1. A method of feeding sacks, tubes or sack lengths one by one from the top of a stack horizontally in a direction generally at right angles to their length, wherein in the initial stage of movement from the top of the stack there is at least a major component of movement in the direction of the length of the sack, tube or sack length.

2. A method as claimed in claim 1, wherein initially the sack, tube or sack length is moved in the direction of the length.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Feeding sacks or bags This invention relates to a method and apparatus for the purpose of feeding paper or plastic sacks or bags, (referred to hereinafter for convenience as sacks), one by one from the top of a stack of sacks, and for similarly feeding tubes or sack lengths during the manufacture of sacks. Considerable difficulty has been encountered when attempting to feed sacks, tubes or sack lengths horizontally in their own plane in a direction at right angles to their major dimension (length) such as is required, for example, when feeding sack lengths to a machine for forming a stitched end closure across one end of the length. The difficulty arises from the fact that the friction beneath the underneath of the top sack length and the top of the next sack length below tends to be sufficiently great that when a horizontal force is applied to the top of the top sack length the sack -length perfqrms a rolling motion with the ply or plies on the top side of the sack length sliding over the ply our plies on the underneath side of the sack length. This effect is pronounced when the sack, tube or sack length has longitudinal side gussets. It is an object of the present invention to provide an improved method and apparatus for feeding sacks, tubes or sack lengths in which the above difficulty is effectively overcome. The present invention consists in a method of feeding sacks, tubes or sack lengths one by one from the top of a stack horizontally in a direction generally at right angles to their length, wherein in the initial stage of movement from the top of the stack there is at least a major component of movement in the direction of the length of the sack, tube or sack length. The invention further consists in apparatus for feeding sacks, tubes or sack lengths one by one from the top of a stack horizontally in a direction generally at right angles to their length, wherein means are provided for applying force in a horizontal direction to the uppermost sack, tube or sack length of the stack such that in the initial stages of movement from the top of the stack there is at least a major component of movement in the direction of the length of the sack, tube or sack length. In the accompanying drawings: Figure 1 is a diagrammatic plan view of one form of apparatus for carrying out the present invention; and Figure 2 is a diagrammatic section taken a line 2-2 of Figure 1 apparatus of Figure 1. In carrying the invention into effect, the invention will be described by way of example with reference to the feeding of sack lengths, one by one, from the top of a stack 11 of sack lengths to pairs of horizontal conveyors 12 and 13 for feeding the sack lengths at right angles to the direction of their length onto a stitcher table 14 having a stitching machine (not shown) for providing a sewn end closure at the end of each sack length. The stack 11 of such lengths rests upon a pneumatic elevator 1 5 having height control so that the top sack length is always at the level of the entry level to conveyors 12 and 13. Further stacks such as stack 11' are delivered when required by conveyor 16, and are fed to the bottom of the stack 11 so that a continuous supply of sacks can be delivered to the stitcher without gaps. Mounted above the stack 11 are two suction heads 1 7 carried on a crossbar 25 pivotally connected by arms 1 8 to fixed supports (not shown). The crossbar 25 is rotated in a circular orbit by means of a motor 1 9 having a cranked arm 20 pivotally connected to the crossbar 25. Rotation of the crossbar 25 causes the heads 17 to perform circular orbits of which are shown at 17. Raising and lowering of the suction heads 17 at the appropriate moments is effected by means of solenoids 26. In operation, a sack length at the top of the stack 11 is initially in the position shown as 22 in Figure 1. The suction heads are lowered onto this sack length when in the positions shown as 1 7 so as to engage the sack near one of the longitudinal margins and, after suction has been applied, arm 20 is rotated to cause the heads to move to the positions shown as 17" and the sack length to be transported to the position shown as 22'. The suction heads 1 7 can be designed so that as soon as they are attached by suction to the top surface of the top sack they move upwards slightly to lift the sack edge slightly. It will be appreciated that as the sack length starts to move, it first travels in the direction of its length and this has been found to facilitate separation from the sack length next below by avoiding the rolling motion described above. Thereafter the suction on one sack length is released and the conveyors 12 and 1 3 feed the sack length with the leading edge 23 of the sack length aligned with the datum line 24 for the stitching machine. The heads 1 7 continue orbiting in a circle until they reach position 1 7 again ready for the next sack length. It will be appreciated that various alternative motions may be applied to the uppermost sack length provided that in the initial stages of movement from the top of the stack there is at least a major component of movement in the direction of its length. CLAIMS

3. A method as claimed in claim 1 or 2, wherein the sack, tube or sack length is moved along an arcuate path.

4. Apparatus for feeding sacks, tubes or sack lengths one by one from the top of a stack horizontally in a direction generally at right angles to their length, wherein means are provided for applying a force in a horizontal direction to the uppermost sack, tube or sack length of the stack such that in the initial stages of movement from the top of the stack there is at least a major component of movement in the direction of the length of the sack, tube or sack length.

5. Apparatus as claimed in claim 4, wherein the means for applying a force includes suction heads engageable with the top surface of the uppermost and means for moving the heads initially in the direction of the length of the sack, tube or sack length.

6. Apparatus as claimed in claim 5, wherein means are provided for moving the heads in an arcuate path.

7. Apparatus as claimed in claim 5 or 6, wherein the suction heads are mounted upon a common crossbar..

8. Apparatus as claimed in claim 5, 6 or 7, wherein each head is designed so that as soon as it is attached by suction to the top surface of the top sack, tube or sack length the head is moved upwardly to lift the sack, tube or sack length.

9. Apparatus as claimed in any one of claims 4 to 8, wherein the means for applying a force engages the uppermost sack, tube or sack length adjacent one of the longitudinal margins.

10. Apparatus for feeding sacks or sack lengths, substantially as described with reference to the accompanying drawings.

11. A method of feeding sacks, tubes or sack lengths, substantially as described with reference to the accompanying drawings.