GB2077699A

GB2077699A - Coiler drum with gripper mechanism

Info

Publication number: GB2077699A
Application number: GB8019584A
Authority: GB
Original assignee: Loewy Robertson Engineering Co Ltd
Current assignee: Loewy Robertson Engineering Co Ltd
Priority date: 1980-06-16
Filing date: 1980-06-16
Publication date: 1981-12-23
Also published as: GB2077699B

Abstract

A coiler drum (2) has a gripper mechanism located in a wedge- shaped slot (26, 26) for holding the end of a strip (M). The gripper mechanism consists basically of a pair of jaws (28) which can move in slot (26) between the wider inner part and the narrower outer part and have complementary wedge surfaces in contact with the wedge surfaces of the slot. Spring (30) urge the jaws apart to facilitate insertion of the end of strip (M) between the jaws. When tension is applied to the strip, the end is gripped by the jaws (28) by wedge action, the jaws having moved to the narrower part of the slot. Externally controlled fluid-operated rams (32, 34) may initially act on the jaws (28) to increase the grip. In modifications, the rams (32, 34) may be replaced by springs acting radially on the jaws and the jaws may take the form of rollers. <IMAGE>

Description

SPECIFICATION Coiler drum with gripper This invention relates to a coiler drum of the type used in conjunction with metal rolling mills or strip processing equipment.

In rolling or processing strip material it is customary to use a drum around which the strip is wound after such treatment. Often the same drum is transferred at a later stage to the ingoing side of the mill or other equipment and then the strip is uncoiled from the drum for further rolling or treatment. In use, the leading end of the strip is often fed into a so-called gripper slot in the periphery of the coiler drum where it is gripped between jaws at least until several convolutions of the strip have been coiled, the coiler drum being rotated at such a speed relative to the rolling mill or processing equipment to maintain the strip under tension continuously. The gripping devices known in the art have frequently comprised externally actuated cam-operated arrangements and these have tended to be unduly complicated and expensive to manufacture.

It is an object of this invention to provide a coiler drum for strip, which includes a gripper device which is simple to operate and maintain and which is comparatively inexpensive to produce.

In accordance with one aspect of the present invention, a coiler drum has a gripper mechanism for gripping the leading end of a strip and the gripper mechanism comprises a pair of gripper jaws located in a wedgeshaped slot such that the application of tension to strip between the jaws in a direction tending to withdraw the leading end from the jaws has the effect of urging the jaws towards one another by wege action and therefore of increasing the gripping force of the jaws on the strip. Preferably the slot has wedge faces which converge towards the exterior of the drum and the jaws have corresponding wedge surfaces; alternatively, the jaws may be in the form of rollers.

In order that the leading edge of the strip may be gripped initially by the jaws sufficiently to prevent the strip withdrawing from the jaws when tension is first applied, there may be means for initially forcing the jaws together. Thus, fluid-operated means may act on at least one of the jaws in a direction forcing the jaws together, or there may be means which urge the jaws in wedging direction in the slot.

The invention will be more readily understood by way of example from the following description of coiler drums, in accordance therewith, reference being made to the accompanying drawings, in which Figure 1 is a part-sectional elevation of a coiler drum, Figure 2 is a section on the line ll-ll of Fig.

1, and Figures 3 and 4 are views similar to Fig. 2, but showing two alternative forms of gripper mechanism.

As seen in Fig. 1 a coiler drum 2 is mounted for rotation in bearings 4 and is driven by means including a drive gear 6 keyed at 8 to an extension 10 of the drum.

The drum is formed with a slot 1 2 having tapered side walls 1 4, and a pair of inserts 1 6 are fitted into that slot, being retained by end plates 1 8. A segment member 20 pivoted on pins 22 is shaped to co-operate with the inserts 1 6 to form a guide slot 24. Each of the inserts 1 6 is formed with a tapered recess 26, the two recesses forming a wedge slot communicating with the guide slot 24; a pair of wedge-shaped jaws in the form of gripper bars 28 is loosely positioned within those recesses. A spring 30 at each end of the gripper bars separates the bars 28.Each insert 1 6 is bored to form a cylinder 32 within which slides a piston 34, and the cylinders connect by bores 36, 38, 40 and by a suitable conduit (not shown) to further bores 42, 44, to a rotary connector 46, and thence to a source of compressed air via a suitable valve (not shown).

When it is desired to commence coiling strip material M, the leading end of the strip is fed into guide slot 24 and into the gap between the separated bars 28. The valve controlling the supply of compressed air is then actuated manually or otherwise to cause air to enter cylinders 32 behind pistons 34 thus causing the bars to close on to the leading end of the strip material M. The drum is rotated to wind the strip on to the periphery of the drum, thus creating tension within the strip which in turn tends to pull the gripper bars further into the tapered recess 36, the resulting wedging action causing the bars to grip even more tightly on the strip material.

When tension in the strip is established there is no further need for the bars to be urged towards each other by pistons 34 and the valve which controls the supply of compressed air to the cylinders 32 can be actuated to shut off that supply.

When the drum is used as an uncoiler from which the strip is fed into a rolling mill or other processing equipment, the drum revolves until most of the strip has been paid off into the processing equipment. The drum is then decelerated until only that part of the tail end of the strip M shown in Fig. 2 remains and there is at that stage no tension in the strip. The gripper bars will then generally fall to the wider part of the wedge slot formed by the recesses 26, being urged apart by their springs 30, and the tail end of the strip is thus released. In case the gripper bars remain wedged within the recess at this stage means may be provided to enable the opera tor positively to thrust the gripper bars towards the wider part of the wedge-shaped recess and so release the strip.Such means may include a member 47, at each end of the drum 2, conveniently guided in the end plate 1 8 to abut against a shoulder 29 formed at each end of the bar 28. A sharp blow on the top of the members 47 by a hammer or other convenient means, is sufficient to free the bars 28 from any locking action within the recess 26.

In Fig. 3 the arrangement of wedge bars 28' within the wedge slot formed by tapered recesses 26' in inserts 16' is similar to that shown in Fig. 2, but in this case a pair of springs 50, one at each end of the coiler drum, constantly urges the gripper bars 28 towards the narrow portion of the slot as indicated by the dotted lines 28A. The end of the entering strip M forces the bars 28' downwardly against the action of the springs 50 to separate those bars sufficiently to allow entry of the strip therebetween. Coiling then proceeds as described in the earlier arrangement; the tension applied to strip M, acting in a direction to withdraw the leading end from the coiler drum, has the effect of increasing the grip of the bars 28' on the strip by wedge action, and thus ensuring that the strip will not withdraw from the coiler drum. Means (not shown) are provided at the ends of the inserts to enable the gripper bars to be depressed manually in order to release their grip on the end of the strip when required.

Fig. 4 shows a further alternative where the gripper bars 28 and 28' are replaced by cylindrical rollers 28" which are positioned in recesses 26" formed in the inserts 16". The action of gripping and releasing the end of the strip is in all other respects similar to that shown in Fig. 3.

Claims

1. A coiler drum having a gripper mechanism for gripping an end of a strip, the gripper mechanism comprising a pair of gripper jaws located in a wedge-shaped slot in the drum such that the application of tension to strip between the jaws in a direction tending to withdraw the end from the jaws has the effect of urging the jaws towards one another by wedge action and therefore of increasing the gripping force of the jaws on the strip.

2. A coiler drum according to claim 1, in which the slot in the drum has wedge faces which converge towards the drum exterior and the jaws have corresponding wedge surfaces.

3. A coiler drum according to claim 2, in which there are remotely controlled fluid operated means carried by the drum and engageable with at least one of the jaws for urging the jaws together.

4. A coiler drum according to claim 2 or claim 3, in which spring means are arranged between the jaws, tending to urge the jaws apart.

5. A coiler drum according to claim 1, in which each jaw is a roller.

6. A coiler drum according to any one of claims 1, 2 or 5, in which biasing means carried within the drum act on the jaws in a direction towards the drum exterior to cause the jaws to grip the strip end.

7. A coiler drum substantially as herein described with reference to the accompanying drawings.