GB2156765A

GB2156765A - Folding device for closing bags

Info

Publication number: GB2156765A
Application number: GB08504540A
Authority: GB
Inventors: Teodoro Concetti; Giuseppe Concetti
Original assignee: DOBSON PARK ENGINEERING PLC
Current assignee: DOBSON PARK ENGINEERING PLC
Priority date: 1984-02-24
Filing date: 1985-02-21
Publication date: 1985-10-16
Also published as: GB8504540D0; GB8404862D0

Abstract

A folding device for closing open mouthed bags includes a pair of parallel elongate guides (24) spaced apart to define a gap through which the top portion (20a) of a bag is fed to close the sides of the bag together with a marginal portion of the bag protruding above the upper longitudinal edges of the guides, and a folding member (26) mounted for movement relative to the guides, the folding member being movable from a first position whereat it resides to one side of said guides to a second position whereat it envelopes the guides, the folding member in moving from its first position to its second position folding the marginal portion of the bag over one of said guides and thereafter maintaining the marginal portion in its folded condition while the folding member is at its second position. <IMAGE>

Description

SPECIFICATION Folding device The present invention relates to a folding device particularly for use in closing and folding over the tops of open mouthed bags prior to sealing.

According to one aspect of the present invention, there is provided a folding device for open mouthed bags, the device including a pair of parallel elongate guides spaced apart to define a gap through which a bag is fed to close the sides of the bag together with a marginal portion of the bag protruding beyond one longitudinal edge of the guides, a folding member mounted for movement relative to the guides, the folding member being movable from a first position whereat it resides to one side of said guides to a second position whereat it envelopes the guides, the folding member in moving from its first position to its second position being arranged to cause the marginal portion of the bag to be folded over one of said guides and thereafter maintaining the marginal portion in its folded condition when the folding member is at its second position.

According to a further aspect of the present invention, there is provided a filled bag closure apparatus including a conveyor for conveying filled bags having open mouthed tops and a folding device as defined above located above the conveyor with said gap extending in the direction of feed of the conveyor.

Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which: Figure 1 is a schematic perspective view of a device according to the present invention; Figures 2 and 3 are similar view to Fig. 1 but showing the device in different stages of the folding process.

The device 10 of the present invention includes a pair of opposed elongate support members 1 2 which are spaced apart to define a longitudinally extending gap 1 4.

The device 10 is supported on a frame (not shown) so as to be positioned above a conveyor (not shown) along which filled bags 20 are conveyed in the direction of arrow A from a filling station whereat they are filled to a discharge station whereat the filled and sealed bags are removed for storage.

The device 10 is arranged so that the longitudinal gap 1 4 extends longitudinally of the bag conveyor i.e. in the direction of feed of the conveyor and the height of the device 10 above the conveyor is arranged so that a sufficient amount of bag material projects above the support members 1 2 for folding purposes.

A pair of elongate guides 24 are mounted on the support members 1 2 on either side of gap 14 to define an upward extension of the gap 14. The guides 24 serve to support the top portion of the bags during the folding process.

Folding of the top portion 20a of the bags is achieved by an elongate folding member 26 which is generally U-shaped in crosssection. The folding member 26 is preferably pivotally mounted on one of the support members 1 2 and is positioned adjacent the guides 24 so as to be movable between a first position whereat it is remote from the guides 24 (as shown in Fig. 1) and a second position whereat it is positioned above the guides 24 so as to envelope the guides (as shown in Fig.

3).

In use a filled bag is conveyed by the bag conveyor toward the device 1 0. At the leading end of the support members 12, the gap 14 widens to provide a lead-in 1 4a for the top portion 20a of the bag. Each support member 1 2 is provided on its underside with conveying means in the form of a continuous chain or belt 28 and these are located so as to grip and move the top portion 20a of the bag along the gap 14. Each continuous chain or belt 28 is entrained around pulleys 30 one of which is driven by a motor (not shown) at a linear speed which is in synchronism with the bag conveyor. Between pulleys 30a and 30b a bearing block 31 (Fig. 1 only) is provided across which the belt or chain passes. Only one bearing block is shown in Fig. 1 for purposes of clarity.The bearing blocks ensure that the belts or chain maintain grip on the top portion of the bag during its passage along gap 14.

The top portion of the bag initially enters the lead-in 1 4a and the sides of the bag are closed thereby prior to entering the gap 14 when the top portion 20a is located within the gap 14, it is gripped by the continuous belts or chains 28 and is moved along the gap to pass between guides 24. The leading ends 24a of guides 24 are turned outwardly to provide a lead-in for the top upper portion of the bag.

When the leading edge of the top portion of the bag has reached a predetermined position (for instance as shown in Fig. 2) its position is sensed by sensing means, say by a microswitch (not shown) and the folding member 26 is operated. In the drawings, the folding member 26 is shown as being secured to a sleeve 27 which is rotatably mounted on a shaft (not shown) supported on one of the support members 1 2. An arm 34 projects from sleeve 27 and is pivotally connected to a ram 35 of a pneumatic or hydraulic ram and cylinder assembly which on actuation by the microswitch causes the sleeve to rotate to move the folding member 26 from its first position to its second position.

An intermediate position is illustrated in Fig.

2 from which it will be seen that the folding member 26 co-operates with one of the guides 24 to cause the end marginal portion 20b of the top portion 20a to fold over the top edge of said one guide 24. It should be borne in mind that during movement of the folding guide the bag is being advanced along gap 14 and so the leading edge 26a of the folding guide is preferably rounded to present a smooth profile to the bag during its movement to its second position (as seen in Fig. 2).

Accordingly the probability of the edge 26a snagging against the bag material is reduced.

When the folding member 26 reaches its second position, the member 26 maintains the now folded over marginal portion 20b in a folded condition as it emerges from the trailing end of the guides 24.

At location F conventional means for sealing the bag top in its folded condition are preferably mounted on the support members 1 2. For instance, the sealing means may take the form of a sewing head for stitching the bag, or a tape applicator or a half sealing device.

Additionally, a conventional trimming device (not shown) may be mounted on the support members at location T and arranged to cut the top portion 20a to leave a predetermined height of the top portion 20a projecting above the support members 12. In this way, a predetermined width of folded marginal portion 20b is repeatedly produced on successive bags.

Preferably at least the trailing end of the folding member 26 projects below the edge of the folded marginal portion 20b when the folding member 26 is in its second position.

To this end, as illustrated, the folding member 26 is preferably provided with a projection 26b. In this way the projection 26b ensures that the folded marginal portion 20b lies flat against the remainder of the top portion 20a as it emerges from the folding member 26.

A sensor (not shown) is provided to sense when the trailing edge of the top portion of the bag has reached a predetermined position in gap 14 so as to actuate return of the folding member 26 back to its first position.

Claims

1. A folding device for open mouthed bags, the device including a pair of parallel elongate guides spaced apart to define a gap through which a bag is fed to close the sides of the bag together with a marginal portion of the bag protruding beyond one longitudinal edge of the guides, a folding member mounted for movement relative to the guides, the folding member being movable from a first position whereat it resides to one side of said guides to a second position whereat it envelopes the guides, the folding member in moving from its first position to its second position being arranged to cause the marginal portion of the bag to be folded over one of said guides and thereafter maintaining the marginal portion in its folded condition when the folding member is at its second position.

2. A folding device according to Claim 1 wherein the conveying means are positioned on opposite sides of the gap, the conveying means being arranged to grip the bag and move it along said gap.

3. A folding device according to Claim 1 or 2 wherein the guides and conveying means are mounted on a pair of support members, the support members being spaced apart to define a continuation of said gap.

4. A folding device according to Claim 3 wherein the support members extend upstream from the guides in the direction of feed of the bags to define a lead-in portion of the gap.

5. A folding device according to Claim 3 or 4 wherein the support members have a downstream extension extending from the guides in the direction of feed of the bags, means for sealing the folded marginal portion of the bags being mounted on said downstream extension.

6. A folding device according to any preceding claim wherein at least the trailing end of the folding member when in its second position extends beyond the terminal end of the folded marginal portion of the bag.

7. A folding device according to any preceding claim, wherein trimming means are provided at an upstream location from the folding member for trimming the bag being fed through the gap so as to ensure that the marginal portion of the bag protruding beyond the guides is of a predetermined dimension.

8. A folding device according to any preceding claim including sensing means for sensing the presence of a bag when it has been fed a predetermined distance along the gap, the sensing means on sensing the presence of the bag being arranged to operate actuation means for moving the folding member from its first position to its second position.

9. A folding device substantially as described herein with reference to and as illustrated in the accompanying drawings.

10. A filled bag closure apparatus including a conveyor for conveying the filled bags having open mouthed tops, a folding device according to any preceding claim located above the conveyor with said gap extending in the direction of feed of the conveyor.