GB2143795A

GB2143795A - A winding drum assembly

Info

Publication number: GB2143795A
Application number: GB08418830A
Authority: GB
Inventors: Udo Gersemkey; Erich Klar
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1983-07-26
Filing date: 1984-07-24
Publication date: 1985-02-20
Also published as: GB2143795B; GB8418830D0

Abstract

A cable 11 is reeled onto and off a drum 6 through a guide 17 which is supported and movable parallel to the drum axis on a pair of chains 24. The chains circulate around pairs of chain wheels 25,25a, the wheels 25 being rotated by gearing 15 driven from the drum. The drum has a cable lifting block 9 to raise the cable above the level of the first layer upon completion thereof. A cable return block 10 may be provided. <IMAGE>

Description

SPECIFICATION A winding drum assembly Federal German specification DE-OS 28 36 036 discloses a winch drum for winding a cable into several layers. However, it is possible for the cable to pile up on the drum end piece once one layer has been wound and then to collapse in an uncontrolled manner at any time, causing the load to drop somewhat owing to the instantaneous reduction in the effective winding diameter.

The present proposal is for a drum which enables the cable to be raised perfectly to start forming an outer layer once one layer has been wound, the cable being deflected into the opposite direction and reliably guided to form the next layer without cable grooves. To this end, use is made of a guide member which has a cable-lifting block, and a cable guide which can be moved parallel to the drum and can change its direction of movement. The cable-lifting block lifts the cable into the outer layer and the cable guide prevents the cable from piling up in an uncontrolled manner in the outer layer. The diversion of the respective outer layer can be initiated by a reversing block which is associated with the cable-lifting block and is preferably fixed to the end piece.The block can be tested at various positions on the end piece until it is found that winding takes place most satisfactorily.

The cable guide may be connected to the drum by way of a drive system which, preferably, employs a system of chains. The cable guide can be provided with a respective trunnion for two adjacent roller chains which are guided around chain return wheels, of which at least one pair lies with its outer tangent approximately below the return end of the cable drum. As the cable guide is joined in its centre to the chain by a journal, the cable guide is slowly halted in its movement along the cable drum as the cable guide passes in the region of the tangents of the chain return wheels. This stopping and slow restart operation is necessary since two layers are wound on top of each other at the end of the cable groove. It also assists the deflection of the cable into the new winding direction owing to the oblique tension occurring at this point.To keep this oblique tension within limits, care should be taken to avoid chain wheels of too great diameter.

The cable guide may have lateral plates which are joined together by webs, opposing upper and lower rollers being provided which are parallel to the drum and rest on the cable. The upper rollers are small guide rollers and serve only to stabilize the position of the cable guide while the lower rollers are large cable rollers which act as deflecting rollers when oblique tension is applied and therefore have a sufficiently great diameter to meet the specifications for the cable diameter.

The chain return wheels lying beneath the cable lifting block are mounted on shafts so that the cable guide can be guided between the chain wheels.

The other chain return wheels can be mounted on a continuous shaft. If the cable is wound in more than two layers, the chain return wheels must also be mounted on separate shafts to permit passage of the cable guide. The path of the cable guide can be limited in its direction of movement by a limit switch at the end facing the cable-lifting block. If the cable is wound in more than two layers, a counter which switches off the motor in good time before the end position is provided instead of the limit switch.

In the drawings: Figure 1 is a side view of a winch drum assembly, Figure 2 is an end view of the assembly, Figure 3 shows to a larger scale the cable guide visible in Figure 2, Figure 4 is an end view to a larger scale of the drive gearing shown in Figure 1, Figure 5 shows the end piece of the winch drum to a larger scale, looking radially on the drum, Figure 6 is an axial view of the drum shown in Figure 5.

Referring to the drawings, a framework 1 supports a platform 2 with rails 2a and a base frame 3 for a winch drum 6 driven through gearing 5 from a motor 4. The drum may be used to wind-up and pay-out a cable, rope or chain, referred to herein collectively as cables. The cable may be used for any known purpose, for example to support a load hook. The surface of the drum has a helical fluting 8 to receive the cable. At one end the drum has an end piece 7 in the form of a disc or plate, adjacent which is a cable lifting block or wedge 9. As the drum rotates, the first layer of cable is laid down in the fluting, proceeding from left to right in Figure 5. When the cable reaches the end of the fluting, it is raised above the level of the first layer of cable by the wedge 9.

A return block or wedge 10 is secured to the endpiece by bolts 28 screwed into selected ones of axial bores 29, and serves to cause the cable to be reeled up in the reverse direction as the drum continues to rotate, and to lie neatly against the first layer of cable.

The cable 11 is paid onto and off the drum by way of a cable guide 17 which moves parallel to the axis of the drum at the speed appropriate to the proper reeling and unreeling of the cable, having regard to the pitch of the fluting 8. The guide comprises a frame assembled from side plates 19 connected on their undersides by webs 18. The side plates have bearings for the shafts 20 of a pair of larger diameter, lower guide rolls 21 and smaller diameter, upper guide rolls 22. The rolls 21 have to turn the cable from or into the dirction it occupies beneath the guide into the correct direction for rolling through the upper rolls 22, which present the cable correctly to the drum, and stabilise the position of the cable guide.

The cable guide is supported and movable parallel to the axis of the drum by a mechanism which is driven from the drum itself. The mechanism includes a pair of parallel drive chains 24 trained around the pairs of chain wheels 25 and 25a. The side plates 19 are provided with coaxial pins 23 which engage between links of one run of the chain, and cause the guide to be entrained thereby.

The drive chains 24 are caused to circulate by a gearing 15, the output shaft 16 of which carries the pair of chain wheels 25. The input shaft of the gearing (the rotary elements of which are not shown) carries a chain wheel 13a which is driven through a chain 14 from a chain wheel 13 mounted on or coupled to the shaft of the drum. The gearing serves to reduce the speed of the drum to the correct speed for the chains 24, and to turn this motion through 903.

The apparatus illustrated in the drawings is designed to allow two layers of cable to be laid down on the drum. The chain wheels 25a are mounted on stub shafts to allow the guide to pass from the lower run to the upper run and vice-versa and so carry out a return movement. The pair of wheels 25a are so located that a tangent may be drawn from their outer diameter (on the side remote from the wheels 25) to the wedge 9 as indicated in Figure 1 to ensure that the cable follows the correct path even at the end of the travel of the guide.

Limit switches 27 are arranged at the other end of the path and are operated by the guide when it reaches the end of of its desired travel either along the upper or lower run of the chain. The motor is then switched off before the cable is unwound as far as its point of connection to the drum, or the load hook encounters the guide.

If three or more layers of cable are to be wound onto the drum, the pair of chain wheels 25 must be suitably located and supported on stub shafts to permit the guide to pass from one run to the other at both ends. A modified drive to enable the two stub shafts to be driven is thereby required. In addition, the motor should desirably be controlled from a system which counts the number of revolutions of the drum or passes of the guide. Other arrangements for driving the chains 24 are possible.

In particular, the gearing may be driven from the motor through a separate transmission.

The guide system may be used with other types of drum.

Claims

1. A winding drum assembly, including a drum provided with at least one end piece associated with a cable lifting block, and a cable guide disposed beneath the drum and movable parallel thereto.

2. A drum assembly according to claim 1, wherein the cable lifting block is provided with a return block.

3. A drum assembly according to claim 1 or claim 2, wherein the cable guide is drivably connected with the cable drum.

4. A drum assembly according to claim 3, wherein the drum has a chain wheel for driving (by way of a chain) a chain wheel of gearing, an output shaft of which is coupled with the cable guide.

5. A drum assembly according to claim 4, wherein the cable guide is coupled by means of pins with adjacent chains which circulate around reversing chain wheels, one pair of which is disposed so that a tangent to the wheel surface is substantially in line with the end disc of the drum.

6. A drum assembly according to claim 5, wherein the cable guide includes side plates which are connected together by webs, in which plates are journalled oppositely disposed upper and lower rolls parallel to the drum.

7. A drum assembly according to claim 6, wherein the upper rolls are smaller in diameter than the lower rolls.

8. A drum assembly according to claim 5, wherein the pair of reversing chain wheels disposed beneath the lifting wedge are journalled on stub shafts to permit the passage of the cable guide, the other pair of reversing chain wheels being mounted on the output shaft of the gearing.

9. A drum assembly according to any preceding claim, wherein, for winding the cable in more than two layers, the output shaft is interrupted to permit the passage of the cable guide.

10. A drum assembly according to any preceding claim, wherein a limit switch is provided at the end of the path of the cable guide remote from the cable lifting wedge.

11. A drum assembly according to any preceding claim, wherein, for winding the cable in more than two layers, the motor is provided with a counter.

12. A cable drum assembly substantially as shown in the drawings.

13. A cable drum assembly comprising a cable drum and a guide for feeding the cable to and from the drum, the guide being supported and movable in the direction parallel to the axis of the drum by a pair of chains circulating on respective chain wheels, one pair of which is drivable from the drum or from a drive system for rotating the drum.