GB2109348A

GB2109348A - Apparatus for coiling strip

Info

Publication number: GB2109348A
Application number: GB08133377A
Authority: GB
Inventors: Kenneth Thomas Lawson
Original assignee: Head Wrightson Machine Co Ltd
Current assignee: Head Wrightson Machine Co Ltd
Priority date: 1981-11-05
Filing date: 1981-11-05
Publication date: 1983-06-02
Also published as: GB2109348B

Abstract

Strip metal is coiled by engaging the leading end with a mandrel until the frictional forces between the coiled strip and the mandrel are sufficient to allow the strip to be coiled by rotating the mandrel. Two pairs of pincer arms (13) and (14), which support a chain of rollers (15) enclose the mandrel and engage the leading end. The right-hand ends of arm (13), as seen in Fig. 1, are joined in by a shaft (18) which supports piston rods (21, 22) which cooperate with cylinders (23) and (24) pivoted at (25) to a shaft (28) which joins the upper ends of arms (14). Arm (14) has attached to it a stop member (29) which limits the clockwise rotation of arm (14) (as seen in Fig. 1) about the shaft (16). The anti-clockwise movement of arm (13) is limited by a bearing pad (30) mounted on the sloping upper surface of the end of carriage (10). The extreme or open positions of the two arms are shown in chain dotted line and the closed position of the two arms in which the chain with its rollers grips the mandrel (31) is shown in firm line. A single chain is employed with rollers which may be as wide or wider than the strip (37) or which extend substantially over the full width of the widest strip to be coiled or which may be appreciably smaller, say 1 DIVIDED 2 to 2/3 of the full width of the widest strip to be coiled around the mandrel 31. The rollers are grooved and engageable with the mandrel. <IMAGE>

Description

SPECIFICATION Apparatus for coiling strip This invention relates to apparatus for coiling strip materials such as metal strip.

Strip materials such as metal strip are usually stored in the form of coils. In the production of metal strip therefore, the finished strip is usually wound on to a cylindrical mandrel. When the coil has reached a convenient size, the strip is sheared, the coil is removed from the mandrel and a new coil is started.

In order to form the initial turns of the coil, the strip must be held in engagement with the mandrel until the frictional forces between the coiled strip and the mandrel are sufficient to allow the strip to be coiled by rotating the mandrel.

One conventional device which is used to form the initial turns of a coil comprises a flexible belt in the form of a C-shaped loop which is wrapped around the mandrel. The sheet is fed between the mandrel and one end of the loop and is guided by the loop into a coil around the mandrel. When such devices are used to form coils of metal strip, the belt is subject to rapid wear and therefore requires frequent replacement.

Broadly in accordance with the present invention we provide apparatus for coiling strip material in which the strip is guided around a cylindrical mandel or tension reel by means of a set of rollers mounted for rotation about axes parallel to the axis of the mandrel and which are engageable with the surface of the mandrel, the rollers being linked together in a chain and the ends of the chain being supported by a pair of hinged or pivoted jaws or pincer arms.

Preferably a single chain of rollers is employed and the rollers extend over a substantial proportion of the full width of the mandrel or of the strip to be coiled. Preferably the rollers extend over half to two thirds of the width of the mandrel or of the maximum width of the strip.

The jaws may be opened and closed by means of an operating device such as a hydraulic or pneumatic piston and cylinder device interconnecting the jaws or pincer arms.

Stops may be provided to limit the movements of the jaws. For example movement of the lower jaw may be limited by abutment of a stop on the jaw against a fixed surface. By using appropriate stops a single operating device or a spaced pair of operating devices, inter-connecting the two jaws may be used both to open and close the jaws and to position the jaws in a vertical plane to encompass a mandrel.

Closing of the jaws enables the chain of rollers to be wrapped around the mandrel or tension reel.

Preferably the chain and pincer arms are pivotally mounted on a movable carriage which may be moved on rails.

In the accompanying drawings: Figure 1 is a side elevation of an apparatus for coiling strip embodying the invention; Figure 2 is an elevation seen in the direction of the arrow A in Fig.1; Figure 3 is an enlarged side elevation of a combined link and guide plate joining a pair of adjacent rollers forming part of the apparatus; Figure 4 is a plan view of portions of the two rollers and the combined link and guide plate shown in Fig. 3; Figure 5 is a section on the line 5-5 which is shown in Fig. 4; and Figure 6 is a hydraulic circuit diagram of part of a hydraulic control system for the apparatus.

In Figs. 1 and 2 the apparatus is shown supported on a carriage 10 which is capable of travelling along rails 11 on wheels 2. The apparatus comprises two pairs of jaws or pincer arms 1 3 and 1 4 which support a chain of rollers 1 5. The arms 1 3 and 14 are pivoted on a shaft 1 6 supported in bearing plates 1 7 from the carriage 10.

The right-hand ends of arm 13, as seen in Fig. 1 are joined by a shaft 1 8 to which are welded two pairs of piston rod supports 1 9 and 20 respectively supporting piston rods 21, 22 which cooperate with cylinders 23 and 24 pivoted at 25 to respective plates 26 and 27 attached to a shaft 28 which joins the upper ends of arms 1 4. Arm 1 4 has attached to it a stop member 29 which limits the clockwise rotation of arm 14 (as seen in Fig.

1) about the shaft 16.

The anti-clockwise movement of arm 1 3 is limited by a bearing pad 30 mounted on the sloping upper surface of the end of carriage 10.

The extreme or open positions of the two arms are shown in chain dotted line in Fig. 1 and the closed position of the two arms in which the chain with its rollers grips the mandrel 31 is shown in firm line.

The chain consists of a series of links 32 which connect together the outer ends of a series of small rollers 33.

One end of the chain is attached to arm 14 or the extension 1 4a thereof by a larger diameter roller 35 and the other end of the chain is supported by a large diameter roller 36. Roller 35 is journaled in the extensions 1 4a of arms 1 4 and roller 36 is journaled in the ends of arms 13.

Thus it is seen that a single chain is employed with rollers which may be as wide or wider than the strip 37 (seen in Fig. 1) or which extend substantially over the full width of the widest strip to be coiled or which may be appreciably smaller, say + to 2/3 of the full width of the widest strip to be coiled around the mandrel 31.

As may be seen more clearly in Figs. 3, 4 and 5 the chain rollers 33, 35 and 36 are all grooved at 33a and guide pieces 39 which extend between the rollers 33, 35 and 36 and form part of the construction of the link assembly, have protrusions 38 which fit between the grooves 33a of the rollers.

The guide pieces 39 help to direct the leading end of strip 37 between successive rollers. The leading end of the strip must be prevented from fouling against the leading edges of the guide pieces 39 and this is achieved by eliminating the gap between the roll and the guide pieces by permitting the guide pieces to fit within the grooves in the roll.

In use the carriage 10 is moved into position and the chain of rollers is placed round the mandrel or tension reel drum 31. The drum is driven and whilst forming the initial wraps of the coil is made to rotate slowly and the lead end of strip 37 is fed between the rolls 35 and 33 and the mandrel 31 to start a new coil. After several wraps of the strip 37 have been wound round the mandrel 31 the torque exerted on the mandrel by the drive is increased so as to develop a suitable recoiling tension in the strip and then the pincer arms 13, 14 are opened and the carriage 10 retracted away from the mandrel 31 so that the coil can build up to a large diameter. The pincer arms 1 3,14 and chain of rollers do not exert a net horizontal or vertical force on the mandrel which would tend to overload the mandrel.There are of course inward loads from each of the rollers but no net unbalanced horizontal or vertical load which would tend to bend the mandrel. At the same time no net horizontal or vertical load builds up on the carriage itself.

As the number of turns of the coil builds up the rolls 33 will move apart and the arms 1 3 and 14 will open slightly. By allowing the carriage to move freely at this stage, the pincer arms will pivot slightly about the mounting on the carriage and at the same time the position of the carriage will change slightly to accommodate the build up of the roll.

The chain rolls will be brought into contact with the mandrel before the strip enters with only very light contact load.

As compared with using a number of chains, a single chain with single wide roller has a number of advantages. Firstly, if there were several chains it will be necessary to ensure that all the chains were uniformly tensioned. Secondly, a single chain covering the full width of the mandrel ensures that no problem arises when narrow strips are being rolled. If a number of chains were used there would be a risk that the edges of the coil of the narrow strip might foul against one of the outer chains.

Although a single hydraulic piston cylinder arrangement may be used it is advantageous to use a pair of piston cylinder arrangements as shown in Fig.2. But in principle a single operator is all that is required. It is not necessary to have a separate piston and cylinder arrangment to adjust the height or position of the pincers. Since the pincer arms are arranged so that the chain engages fully round the mandrel the arms become self adjusting onto the roll as the piston cylinder is operated.

Stops 29 and 30 are provided to ensure that, when the arms are in the open position as the wrapper approaches the mandrel prior to starting a new coil, the rollers 35 and 36 can move freely past the mandrel without fouling. By using a single jack or pair of jacks to close the pincer arms together it is possible to ensure that the chain rollers exert the correct loads on the mandrel or tension reel drum, load applied by the rolls is determined by the geometry of the wrapper and the load exerted by the jacks.

In previous proposals a number of jacks have been used to position the chain round a tension wheel drum, control the load supplied to the chain, and to control the vertical position of the arms in space. These jack loads are not independent and have to be controlled with regard to one another. In the design in accordance with the present invention this problem is avoided.

As can be seen from Fig. 6 which shows the hydraulic control circuit for the jacks which wrap the chain around the mandrel and exert a tension on the chain, when the strip enters between the mandrel and the rolls and thus forces the arms 1 3 and 14 apart, oil is prevented from leaving the jack or piston cylinder arrangement by the non-return valve and so pressure will be developed in the oil which will tend to increase the forces on the chain rolls. This will aid in driving the strip round the drum. A pressure relief valve is included in the hydraulic circuit which is preset so that oil pressure will not exceed a predetermined value so that the loads exerted by chain rollers are not excessive.

Valve 1 3 is opened so that oil flows to the piston side of the jacks 21, 22. A pressure reducing valve 11 is set at low pressure so that the load exerted by the chain on the mandrel is very low. 5 is non-return valve.

When the strip enters the wrapper, which it is able to do fairly easily, because of the low tension, then the chain rolls are forced away from the mandrel. The strip thus tends to force the jaws of the wrapper apart and thus the actuating jacks 21, 22 are made to retract slightly.

Oil is not able to flow from the piston sides of the jacks because of the non-return valve 5, but there is another pressure relisf valve 6 which can be adjusted over a wide range of pressures from 0 - 2000 psi. Pressure would be adjusted during commissioning so that a suitable high tension was developed in the chain to help bend the leading end of the strip and help form it around the mandel during the initial stages of coiling. When a sufficient number of wraps (say 4 to 5 for instance) had been formed on the mandrel, then the load on the motor driving the mandrel would be increased so as to apply a significant tension to the strip approaching the mandrel and once a sufficient tension had been established, then the chain wrapper would be retracted out of the way.

The chain wrapper jaws are released by operating valve 1 3 to apply pressure to the piston rod side of jack and valve 2 would also be actuated to allow oil to flow unrestricted from the piston side of the jack.

As described above, the chain wrapper is mounted on a carriage which is retracted to a position remote from the tension reel. The carriage and chain wrapper are brought into operation by actuation of a jack moving the carriage. Once in position the jacks controlling the jaws of the wrapper are actuated to grip the mandrel and when this has been done a valve (not shown) is actuated so as to permit the carriage to move freely and take up any position dictated by the geometry of the roller chain which is now clamped around the mandrel. When coiling is completed the carriage is retracted to its non-operating position.

The apparatus illustrated in the drawings is particularly suitable for use in coiling metal strips such as cold strip steel of 0.005 inches to T of an inch in thickness on mandrels which are normally 20" to 3" in diameter.

Similar apparatus with more robust construction could be used to coil thicker metal strip and with appropriate selection of materials of construction such a wrapper could be used for hot strip.

The apparatus might also be used in coiling material such as plastic sheet, thick paper, corrugated cardboard and similar materials where it is necessary to provide means to start the strip on a mandrel so as to commence a coil.

Claims

1. Apparatus for coiling strip material in which the strip is guided around a cylindrical mandrel or tension reel, the apparatus comprising means for guiding the strip, in the form of a set of rollers mounted for rotation about axes parallel to the axis of the mandrel and engageable with the surface of the mandrel, the rollers being linked together in a chain and the ends of the chain being supported by a pair of hinged or pivoted jaws or pincer arms.

2. Apparatus according to claim 1 in which said set of rollers comprises a single chain of rollers and the rollers extend over a substantial proportion of the full width of the mandrel or of the strip to be coiled.

3. Apparatus according to claim 2 and in which the rollers extend over half to two thirds of the width of the mandrel or of the maximum width of the strip.

4. Apparatus according to any preceding claim and comprising an operating device in the form of a hydraulic or pneumatic piston and cylinder device interconnecting the jaws or pincer arms by which the jaws may be opened and closed.

5. Apparatus according to any preceding claim in which stops are provided to limit the movements of the jaws.

6. Apparatus according to claim 5 in which movement of the lower jaw is limited by abutment of a stop on the jaw against a fixed surface.

7. Apparatus according to any of claims 1 to 5 in which by use of appropriate stops a single operating device or a spaced pair of operating devices, interconnecting the two jaws are enabled both to open and to close the jaws and to position the jaws in a vertical plane to encompass a mandrel.

8. Apparatus according to any preceding claim in which the chain and pincer arms are pivotally mounted on a movable carriage.

9. Apparatus according to claim 8 and in which said carriage is movable on rails.

10. Apparatus for coiling strip according to claim 1 in which the pivoted arms have a common pivot axis and one of the arms has a pivoted extension the pivoted extension and one end of the other arm being interconnected by a piston and cylinder arrangement and the movement of both arms being limited by stops.

11. Apparatus for coiling strip according to claim 10 in which the pivoted extension and one end of the other arm are intercon nected by a piston and cylinder arrangement and the movement of both arms being limited by stops.

1 2. Apparatus for coiling strip material substantially as hereinbefore particularly described and as illustrated in the accompanying drawings.

11. Apparatus for coiling strip material substantially as hereinbefore particularly described and as illustrated in the accompanying drawings.

CLAIMS (5 Jan 1983)

1. Apparatus for coiling strip material in which the strip is guided around a cylindrical mandrel or tension reel, the apparatus comprising means for guiding the strip, in the form of a set of rollers mounted for rotation about axes parallel to the axis of the mandrel and engageable with the surface of the mandrel, the rollers being linked together in a chain and the ends of the chain being supported by a pair of hinged or pivoted jaws or pincer arms, and in which the pivoted jaws or pincer arms have a common pivot axis.

10. Apparatus for coiling strip according to claim 1 in which one of the arms has a pivoted extension the pivoted extension which supports one end of the chain.