GB1588839A

GB1588839A - Reeling systems

Info

Publication number: GB1588839A
Application number: GB1762678A
Authority: GB
Original assignee: Ferranti PLC
Current assignee: Ferranti International PLC
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-04-29

Description

(54) IMPROVEMENTS RELATING TO REELING SYSTEMS (71) We, FERRANTI LIMITED, a Com- pany registered under the Laws of Great Britain, of Hollinwood in the County of Lancaster, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to the reeling of wires or ropes onto winch drums.

The desirability of uniform layering of wires or the like reeled onto a winch drum have long been recognised. In conventional crane arrangements where a wire extends between a sheave at one end of a long boom and a winch drum at the other end layering occurs freely where the ends of the winch drum subtend an angle of 10 or 20 with the remote end of the boom. With such geometry, over a large part of the drum length the wire encounters the drum substantially normally to the axis of rotation of the drum. At the ends of the drum, bounded by flanges, the cable makes a small angle of 10 or so from the normal against the reeling direction so that as the wire encounters the flange it tends to climb onto the final turn of the layer and form the first turn of a further layer.

The situation is more difficult where such a long operation between the sheave and drum is unobtainable, for instance as commonly found on a deck winch. To cater for such arrangements proposals have been made to perform what may be called "power reeling" in which the wire is constrained to pass over a sheave located a short distance from the drum and which sheave is caused to reciprocate parallel to.

the axis of the drum to layer the wire thereon. The most common form of drive for the sheave is a screw thread whose pitch is related to the diameter of the wire and is driven at a speed related to that of the drum through gearing from the winch. The sheave maintains the wire normal to the axis of the drum at all times as it forms the layers, changing direction of travel at drum ends to form new layers. If any changes in wire diameter or wear in the screw or gearing throws the sheave out of synchronisation with the drum layering becomes uneven and apart from inefficient wire storage on the drum wire jams can result.

An arrangement for controlling the angle of fleeting a wire or rope, that is, the angle made to the normal to the drum axis, in reeling and which overcomes many of the drawbacks of drum speed related systems has been described in British Patent Specification No. 1,393,193. In the arrangement therein described wire is passed between guide pulleys mounted on a carriage movable parallel to the axis of the winch drum under the action of a ram. The position of the ram is controlled by sensors, contacting the wire between the pulleys and the winch drum. The sensors detect deviation from a preset value of the angle made by the wire between the pulley and drum and the normal to the drum axis, that is, the fleeting angle, causing the pulley to be moved by the ram to restore the angle.The angle is maintained at a small value against the reeling direction to ensure the successful formation of a subsequent layer when the ends of the drum are reached. It will be appreciated that the sense of the angle must be changed depending on the sense of the reeling and that the sensor must be adjusted accurately to the preset values of angle, that is, one for each direction, and means to effect such adjustment is exposed to abuse in operation.

Furthermore, the guide pulleys are constrained to move parallel to the winch drum axis and in order to pass the wire at an angle to the normal to the drum axis these pulleys must be rotatable about axes perpendicular to winch drum axis thereby limiting the arrangement to use with wire which is substantially in the plane of the fleeting angle.

In many applications, such as deck winching it is possible for the whole wire to be in a horizontal plane even though the angle, in the plane, at which the wire approaches the winch may vary widely; such a situation is envisaged by the aforemcntioned specification No. 1,393,193.

There are situations however where the wire must approach the reeling arrangement from out of the plane containing the reeling arrangement and drum requiring the wire to be passed around a sheave or pulley rotatable about an axis in a parallel to the plane containing the axis of the drum bcfore entering the reeling arrangement. Where there is adequate space to mount the sheave sufficiently far from the movable pulleys of the reeling arrangement the arrangement described in the aforementioned specification is satisfactory but where space is restricted the arrangement is inadequate.

it is an object of the present invention to provide an arrangement for reeling wire or the like which mitigates some or all of the disadvantages of known systems.

According to the present invention an arrangement for reeling wire or the like onto a drum comprises a substantially planar four-arm linkage having a fixed base arm extending parallel to the axis of the drum, a pair of joining arms pivotally attached to the base arm at points symmetrically disposed about a point corresponding to the centre of the drum and a support arm pivotally connected to, and between, the other ends of the joining arms, a sheave, over which wire passes to the drum, carried by the support arm and rotatable about an axis parallel to the arm the linkage being arranged such that when wire is fed by the sheave onto the centre of the drum the plane of the sheave is normal to the axis of the drum and the joining arms are inclined towards each other so as to converge away from the drum towards an imaginary point in the plane of the sheave, remote from the linkage, about which imaginary point the plane of the sheave is caused to rotate during motion of the linkage, such that as wire is fed to either end of the drum the plane of the sheave is inclined to a normal to the axis of the drum at a fleeting angle suitable to start a further layer of wire, and control means responsive to the detection of deviation of that portion of wire between the sheave and the drum out of the plane of the sheave to cause the linkage to be pivoted to move the sheave so as to be coplanar with the wire.

Where the lengths of the base and support arms are of the same order of magni tticle as the length of the winch drum the joining arms may be inclined towards each other by the fleeting angle desired at each end of the drum.

The angles may be chosen in practice such that when the plane of the sheave intersects the centre of the drum the joining arms are equally but oppositely inclined to the plane of the sheave at an angle in the range 10 to 10, and preferably 10.

The control means may include sensor means carried by the support arm between the sheave and the drum and responsive to the detection of deviation between the direction of the wire between the sheave and the drum and the plane of the sheave to produce a signal indicative of the sense of the deviation. The sensor means may comprise a fork arranged to straddle the wire and signal producing means responsive to movement of wire passing through the fork transversely to the direction in which the wire extends between the sheave and the drum.

The fork may contact the wire and be moved thereby. The signal producing means may comprise switching means and may be electrical, pneumatic or hydraulic. The signal producing means may altematively produce a signal proportional to the deviation, either hydraulically, pneumatically, or electrically.

The control means may apply a force to the rod by means of a double acting hydraulic ram.

The control means may then include a source of hydraulic pressure and a control valve responsive to signals from the sensor means to apply hydraulic pressure to the ram in such a sense as to move the linkage to reduce deviation in the sensor means.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings; in which: Figure 1 is a perspective view of a reeling arrangement according to the present invention and a drum onto which wire is reeled.

Figure 2 is a plan view of the reeling arrangement of Figure 1 showing the control means and with the arrangement symmetrically disposed for reeling onto the centre of the drum, Figure 3 is a plan view of the reeling arrangement, similar to Figure 2 but showing the disposition of parts when reeling onto one end of the drum, Figure 4 is a diagrammatic plan view of the reeling arrangement shown in Figures 1 to 3 to illustrate the motion of the sheave by the linkage, and Figure 5 is a diagrammatic plan view similar to Figure 4 but showing an alternative construction of linkage.

Referring to Figure 1 a winch drum 10 is mounted for rotation about an axis 11 by drive means (not shown) to pull in, and store. a wire cable 12, the wire being guided onto the drum by reeling arrangement 13. The reeling arrangement comprises a substantially planar four-arm linkage 14 comprising a fixed base arm 15 extending parallel to the axis 11 of the drum, a pair of joining arms 16, 17 extending from the base arm 15 towards the drum and freely jointed to the base arm at points symmetrically disposed about a centre point 151 of the arm corresponding with the centre of the drum axis. The other ends of the arms 16, 17 are pivotally joined to a support arm 18. The support arm 18 carries a sheave 19 over which the wire 12 passes to the drum.

The sheave 19 is freely rotatable about an axis 20 extending parallel to the arm 18.

The linkage is movable by control means comprising a double acting hydraulic ram 21 shown pivotally connected to the arm 16 and sensor means 22 carried by the support arm 18.

Referring now to Figure 2, when the linkage is symmetrically disposed the support arm 18 and axis 20 of the sheave are parallel to the base arm and drum axis and the plane of the sheave 19 is normal to the drum axis 11 such that wire is reeled from the sheave onto the centre of the drum. In this position the joining arms 16, 17 are arranged to converge towards each other away from the drum and if extended would meet in the plane of the sheave at an imaginary point 23 remote from the arrangement as illustrated by the broken lines.

The control means shown in Figure 2 comprises a double acting hydraulic ram 21 arranged to receive hydraulic fluid under pressure from a source (not shown) by way of pipe 24 and valve 25. Fluid from the ram is returned to a sump (not shown) by way of pipe 26. Pipes 27 lead from the valve to the ram and the valve is operated by solenoids 28 to be closed or open to the passage of fluid according to the supply of signals to the solenoids. The control means also comprises sensor means 22. The sensor means comprises a fork 29 arranged to straddle the wire 12 connected by a rod 30 to signal producing means 31.The signal producing means 31 comprises a bidirectional electric switch which switches on electrical supply 32 between two output lines 33 and 34 depending on the sense of any deviation of the fork 29 from a neutral position caused by movement of the wire 12 transversely to its direction of motion towards the drums. The lines 33;and 34 are connected to solenoids 28 such that if the wire moves in an upwards direction in the Figure due to reeling on the drum and out of the plane of the sheave 19 the valve 25 is operated to cause the ram 21 to push the arm 16 in the same upward direction. When the sheave has moved such that the cable is again in the plane of the sheave the switch 31 has moved with respect to the fork to the neutral position and the valve 25 turned off.Any overshoot or movement in the opposite direction causes the valve 25 to be energised oppositely and the arm 16 pulled by ram 21.

Because the position of the sheave is controlled the wire is effectively reeled onto the drum freely, located by adjacent turns on the drum the control means functioning to maintain it such that the cable always leaves the sheave 19 in the plane of the sheave and appears to emanate from the imaginary point 23.

As the cable reels orito the drum it will be appreciated that it moves upwards in the view of Figure 2 and the control means causes the sheave 19 to be moved upwards also. Movement of the sheave is however constrained by the geometry of the linkage and the plane of the sheave is effectively pivoted about the imaginary point 23 as shown in Figure 3. Now the control means ensures that the wire leaves the sheave in the plane thereof and if this plane is inclined to the normal to the drum axis by an angle suited to fleeting the cable approaches the drum at this angle, say a, and when the flange prevents further reeling a new layer is started. As the new layer forms successive turns of cable move in a downwards direction in the Figures and the control means causes the sheave to follow until reversed, when the other flange is reached.

Thus it will be seen that the geometry of the linkage is arranged so that the plane of the sheave moves between maximum angles to the normal to the drum axis of * a, which as stated earlier are in practice each about 10.

It will be appreciated that the angles made by the arms 16, 17 to the base arm 15 do not matter providing they converge to the point 23.

In practice for a drum length of about 0.5 metres and a fleeting angle of 10 the distance of the imaginary point 23 from the drum will be just under 15 metres so for elements of the linkage 14 of the same order of magnitude as the drum length compared with the distance from the point 23 the arms 16 and 17 may each be inclined to the normal to the base arm 15 by the fleeting angle ce of 10 to give satisfactory results.

Figure 4 shows diagrammatically that as the linkage moves and the sheave 19 translates the sheave 19 follows a path centred on the mid-point of the base arm 15, the support arm being shown for different positions by broken lines. It will be seen however that the plane of the sheave 19 actually pivots about the imaginary point 23 to which the joining arms 16, 17 converge.

Figure 5 illustrates that it is in fact possible for the shorter arm more remote from the drum corresponding to 15 in Figures 1 to 4 to be the support arm provided the joining arms still converge away from the drum. The sheave now moves along a path centred on the mid-point of the arm nearer the drum but the plane of the sheave is still effectively pivoted about the imaginary point.

It will be appreciated that in the control means shown in Figure 2 several variations may be employed both in respect of the sensor means and the valve 25. The sensor means, instead of effecting a switching action may provide proportional control signal to the valve 26 and the signals, whether switched or proportional, may be hydraulic or pneumatic instead of electrical. Similarly the sensor detects deviations by mechanical displacement; suitable signals may be provided by other forms of sensors such as optical or electromagnetic in which physical contact with the wire is avoided and sudden changes in its diameter less likely to cause damage to the sensor.

Furthermore the motion imparted to the linkage by ram 21 may be applied, for instance, at the joint between arm 16 and arm 15 by a rotary motor, hydraulic or electrical.

In all of the above arrangements it will be appreciated that when the arrangement is assembled it requires no setting up in the sense that the control means does not require to have adjustments made to incorporate the fleeting angle in the sensor means, control being independent of the fleeting angle which varies throughout the reeling.

Also the arrangement is able to accept wire approaching from outside the plane in which it travels between the reeling arrangement and the drum.

The shcave as described above it attached directly to the support arm. The sheave may be part of a buffer arrangement for absorbing sudden! changes in tension in the cable.

The buffer arrangement may comprise a hydraulic ram cylinder fixed to the support arm 18 and a piston slidable in the cylinder, against hydraulic resistance, carrying the sheave 19. The cylinder may extend towards the base arm 15 so that the combined arrangement takes up little further space than the simple reeling arrangement.

WHAT WE CLAIM IS:- 1. An arrangement for reeling wire or the like onto a drum comprising a substantially planar four-arm linkage having a fixed base arm extending parallel to the axis of the drum, a pair of joining arms pivotally attached to the base arm at points symmetrically disposed about a point corresponding to the centre of the drum and a support arm pivotally connected to, and between, the other ends of the joining arms, a sheave, over which wire passes to the drum, carried by the support arm and rotatable about an axis parallel to the arm the linkage being arranged such that when wire is fed by the sheave onto the centre of the drum the plane of the sheave is normal to the axis of the drum and the joining arms are inclined towards each other so as to converge away from the drum towards an imaginary point in the plane of the sheave, remote from the linkage, about which imaginary point the plane of the sheave is caused to rotate during motion of the linkage, such that as wire is fed to either end of the drum the plane of the sheave is inclined to a normal to the axis of the drum at a fleeting angle suitable to start a further layer of wire, and control means responsive to the detection of deviation of that portion of wire between the sheave and the drum out of the plane of the sheave to cause the linkage to be pivoted to move the sheave so as to be coplanar with the wire.

2. A reeling arrangement as claimed in claim 1 in which the lengths of the base and support arms are of the same order of magnitude as the length of the winch drum and the joining arms are inclined towards each other by the fleeting angle desired at each end of the drum.

3. A reeling arrangement as claimed in claim 2 in which when the plane of the sheave intersects the centre of the drum the joining arms are equally but oppositely inclined to the plane of the sheave at an angle in the range -1-0 to 1-r- .

4. A reeling arrangement as claimed in claim 3 in which the angle is 1 .

5. A reeling arrangement as claimed in any one of the preceding claims in which the control means includes sensor means carried by the support arm between the sheave and the drum and responsive to the detection of deviation between the direction of the wire between the sheave and the drum and the plane of the sheave to produce a signal indicative of the sense of the deviation.

6. A reeling arrangement as claimed in claim 5 in which the sensor means comprises a fork arranged to straddle the wire and signal producing means responsive to movement of wire passing through the work transversely to the direction in which the wire extends between the sheave and the drum.

7. A reeling arrangement as claimed in claim 5 in which the fork is in contact with the wire and the signal producing means is responsive to movement of the fork caused by the wire.

8. A reeling arrangement as claimed in claim 6 or claim 7 in which the signal producing means comprises switching means operable to produce a signal when the fork has moved a predetermined distance.

9. A reeling arrangement as claimed in claim 6 or claim 7 in which the signal producing means comprises a transducer operable to produce a signal having a magnitude proportional to the deviation.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. still effectively pivoted about the imaginary point. It will be appreciated that in the control means shown in Figure 2 several variations may be employed both in respect of the sensor means and the valve 25. The sensor means, instead of effecting a switching action may provide proportional control signal to the valve 26 and the signals, whether switched or proportional, may be hydraulic or pneumatic instead of electrical. Similarly the sensor detects deviations by mechanical displacement; suitable signals may be provided by other forms of sensors such as optical or electromagnetic in which physical contact with the wire is avoided and sudden changes in its diameter less likely to cause damage to the sensor. Furthermore the motion imparted to the linkage by ram 21 may be applied, for instance, at the joint between arm 16 and arm 15 by a rotary motor, hydraulic or electrical. In all of the above arrangements it will be appreciated that when the arrangement is assembled it requires no setting up in the sense that the control means does not require to have adjustments made to incorporate the fleeting angle in the sensor means, control being independent of the fleeting angle which varies throughout the reeling. Also the arrangement is able to accept wire approaching from outside the plane in which it travels between the reeling arrangement and the drum. The shcave as described above it attached directly to the support arm. The sheave may be part of a buffer arrangement for absorbing sudden! changes in tension in the cable. The buffer arrangement may comprise a hydraulic ram cylinder fixed to the support arm 18 and a piston slidable in the cylinder, against hydraulic resistance, carrying the sheave 19. The cylinder may extend towards the base arm 15 so that the combined arrangement takes up little further space than the simple reeling arrangement. WHAT WE CLAIM IS:-

1. An arrangement for reeling wire or the like onto a drum comprising a substantially planar four-arm linkage having a fixed base arm extending parallel to the axis of the drum, a pair of joining arms pivotally attached to the base arm at points symmetrically disposed about a point corresponding to the centre of the drum and a support arm pivotally connected to, and between, the other ends of the joining arms, a sheave, over which wire passes to the drum, carried by the support arm and rotatable about an axis parallel to the arm the linkage being arranged such that when wire is fed by the sheave onto the centre of the drum the plane of the sheave is normal to the axis of the drum and the joining arms are inclined towards each other so as to converge away from the drum towards an imaginary point in the plane of the sheave, remote from the linkage, about which imaginary point the plane of the sheave is caused to rotate during motion of the linkage, such that as wire is fed to either end of the drum the plane of the sheave is inclined to a normal to the axis of the drum at a fleeting angle suitable to start a further layer of wire, and control means responsive to the detection of deviation of that portion of wire between the sheave and the drum out of the plane of the sheave to cause the linkage to be pivoted to move the sheave so as to be coplanar with the wire.

4. A reeling arrangement as claimed in claim 3 in which the angle is 1 .

10. A reeling arrangement as claimed in

any one of claims 7 to 9 in which the signal is electrical.

11. A reeling arrangement as claimed in any one of claims 5 to 10 in which the control means includes a double acting hydraulic ram by way of which a force may be applied to the linkage.

12. A reeling arrangement as claimed in claim 11 in which the control means includes a source of hydraulic pressure and a control valve responsive to signals from the sensor means to apply hydraulic pressure to the ram in such a sense as to move the linkage to reduce the deviation in the sensor means.

13. A reeling arrangement as claimed in any one of the preceding claims in which the sheave is part of a buffer arrangement for absorbing sudden changes of tension in the wire, the buffer arrangement comprising a hydraulic ram cylinder fixed to the support arm of the linkage and a hydraulic ram piston movable within the cylinder and arranged to support the sheave.

14. An arrangement for reeling wire or the like onto a drum substantially as herein described with reference to, and as shown by, Figures 1 to 4 or Figure 5 of the accompanying drawings.