GB2306935A - A winch assembly with safety catch - Google Patents

Abstract

A winch assembly includes a winching mechanism with a shaft 171 extending to a point remote from the winch housing and a safety catch with a cranked arm 25 pivotally mounted to the housing with a release mechanism adjacent to and supporting the shaft to release the catch while the mechanism is operated. The release mechanism preferably comprises a sleeve 180 which surrounds the shaft and is moved by a tool which engages the shaft to move the arm against a bias spring 200 which normally forces the catch towards the engaged position.

Description

WINCH The present invention relates to a winch including a safety catch and a release member to displace an arm of the safety catch from a catch position.

EP-A-0612653 discloses a winch comprising a winching mechanism and a safety catch in a common housing. A winch cable is provided for suspending a vehicle spare wheel in a stowed position under a vehicle chassis. The safety catch operates to prevent the wheel from lowering to the ground in the event that the suspension by the cable fails, e.g. by breaking. In order to do this, the catch is normally in an operative position to prevent lowering of the wheel to the ground. When it is desired purposely to lower the wheel from the stowed position, a tool is inserted into a socket and over a hub of the winching mechanism and rotated in order to apply a drive force to the winching mechanism to cause unwinding of the cable.Insertion of the tool in the socket automatically moves the safety catch from the operative position to a retracted position in which the catch does not prevent lowering of the wheel to the ground.

There is a problem, however, with the apparatus disclosed in EP-A-0612653, because the safety catch must be sited in the same general location on the vehicle as the winching mechanism. This is because movement of the catch from the operational position is dependent upon physical contact of the catch with the tool as the latter is inserted onto the hub of the winching mechanism. It is necessary to mount the winching mechanism at a location on the vehicle above a suitable position for stowing the spare wheel. This makes access to the winching mechanism, to lower the spare wheel, difficult.

EP-A-0501644, US-A-5188341 and WO 94/07735 disclose winches in which the safety catch is sited at the same location on the vehicle where the drive force is applied to operate the winching mechanism. These winches also have relatively complex release members to move the catch from the operational position.

The present invention enables, when required, mounting of the safety catch on the vehicle at an accessible location remote from the location where the drive force is applied to operate the winching mechanism. The catch release mechanism of the winch of the present invention also has a relatively simple construction.

The present invention provides a winch comprising a body; a winch cable device including a winch cable connected with suspension means for suspending a vehicle wheel from the cable; a winching mechanism connected to the cable for raising and lowering the suspension means, the winching mechanism including an actuating shaft that extends transversely relative to the cable and has an end portion that is remote from the cable and is engageable by a tool to rotate the actuating shaft; a safety catch including an arm pivotally mounted on the body, the arm being biased to a catch position in which the arm is located to catch the winch cable device, the safety catch including a release member attached to the arm and adjacent to and supporting the shaft, the release member extending to a position adjacent said end portion of the shaft so as to be engaged, in use, by the tool and moved thereby axially relative to the shaft to move the arm, against the bias, to a position in which the arm is displaced from the catch position; and guide means for mounting remote from the body for slidably receiving and supporting the release member.

Reference is now made to the following figures in which: Figure 1 is a prior art winch having a safety catch in a retracted position, as disclosed in EP-A-0612653; Figure 2 shows detail of the safety catch of the winch of Figure 1, but in the operational position; and Figure 3 shows a winch in accordance with an embodiment of the invention.

The winch 10 disclosed in EP-A-0612653 comprises a wheel bracket 11, which is used in a conventional manner to bolt to a vehicle spare wheel (not shown), for stowing the wheel under a vehicle chassis (not shown). The bracket 11 is suspended by a suspension device from a winch cable 14. The winch 10 comprises a casing which includes an elongate, cylindrical housing 22 having a space 23. A guide assembly 32 including a cup-shaped plate 19 is suspended from the cable 14 and extends across the space 23 to the housing wall 24. The winch cable is fastened to a self-locking winch mechanism 31 which is actuable by rotation of an actuating shaft 71.

A safety catch is provided comprising an arm 25 pivotally attached at a pivot point 26 to the outside of the casing, the pivot point 26 being intermediate the ends 27, 28 of the arm 25. The arm 25 has a catch portion in the form of a hook 29 at one end 28.

In the prior art arrangement, as shown in Figs 1 and 2, the arm 25 is biased by a return spring 200 to an operable position in which the hook 29 projects through an opening 30 in the housing wall 24 and into the space 23.

In use, a tool (not shown) is engaged with a hexagonal hub 70 on the shaft and rotated, thereby rotating the actuating shaft, unwinding the winch cable 14 and lowering the bracket 11 from the vehicle chassis. The arm 25 is moved from the operable position to a retracted position (Fig. 1) against the bias, when the tool is engaged on the hub 70. The tool engages the end part 27 of the arm to effect this movement. In the retracted position, the hook 29 is retracted from the opening 30, so that the hook is clear of the space 23 and the cup-shaped plate 19 is free to move past the opening 30 as the winch cable is unwound. The guide assembly 32 acts to guide longitudinal movement in the housing 22.

In the event of failure of the cable, the wheel bracket 11 moves away from the vehicle chassis and the cup-shaped plate 19 moves in the space 23 towards the hook 29 that occupies the space 23. Engagement of the hook 29 and the plate 19 limits further movement of the wheel bracket 11.

Reference is now made to an embodiment of the present invention as in Figure 3, which shows a winch. This winch is substantially as disclosed in EP-A-0612653, except for the winching mechanism, which is modified according to the present invention, as shown in Figure 3.

The modified winching mechanism 131, which can be self-locking, includes an elongate actuating shaft 171 that extends in a direction away from the cable 14 to a position remote from the casing to which the safety catch arm 25 is pivotally mounted. The shaft 171 terminates in a hexagonal hub 170 at its end remote from the cable 14.

A release member 180, in the form of a sleeve or tube surrounds the shaft 171 and extends from the end part 27 of the catch arm 25 to the end of the hub 170 remote from the cable 14 (phantom line "X" in Fig 3).

In an alternative embodiment (not shown) the release member 180 extends to a position short of the end of the hub 170 remote from the cable. In addition, the release member 180 need not be in the form of a tube or sleeve, and need not surround the shaft 171. In addition, the release member 180, may be integrally moulded with the arm 25, which provides savings in manufacturing costs of the winch.

The release member 180 is movable relative to the shaft 171.

Preferably, the shaft 171 is supported inside the release member 180 by a bushing (not shown) to provide a bearing surface for movement of the shaft 171 relative to the release member 180.

The release member 180 is supported by being slidably received by at least one support 210, which enables movement of the release member 180 relative to the shaft 171. The support may be mounted on the vehicle chassis remote from the winch casing. The support 210 acts as a guide, guiding the movement of the release member 180 relative to the shaft 171.

As in the winch of EP-A-0612653, the arm 25 is biased to an operable position (not shown in Fig 3) in which the hook 29 projects through the opening 30 in the housing 22 and into the space 23.

In order to wind or unwind the cable of the winch of the present invention (Fig 3), a tool (not shown) is engaged with the hub 170, which causes the release member 180 to be pushed away from the hub 170 and towards the cable 14 to the position shown in solid line in Fig 3. As the release member 180 is being pushed, it pushes the end part of the arm 27 towards the cable, thereby moving the arm 25, against the bias of return spring 200, to a position in which the hook 29 of the arm 25 is retracted from the opening 30, as shown in Fig 3. The tool is rotated while the release member 180 is used to hold the hook 29 in this retracted position.

When the cable 14 has been wound or unwound as appropriate, the tool is disengaged from the hub 170 and the end part 27 of the arm 25 moves away from the cable 14 under the bias of the return spring 200, thereby causing the end part 27 to push the release member 180 away from the cable 14 and to the end of the hub 170 remote from the cable (phantom line in Fig 3). The movement of the arm 25 under the bias also causes the hook 29 to move into the opening 30 to the operable catch position.

The winch of the present invention has the advantage that the hub 170 is located remote from the cable 14 and safety catch, so that the drive forces for the winching mechanism are inputted at a location remote from the cable and catch. The winch also has a relatively simple construction.

Claims (5)

1. A winch comprising a body; a winch cable device including a winch cable connected with suspension means for suspending a vehicle wheel from the cable; a winching mechanism connected to the cable for raising and lowering the suspension means, the winching mechanism including an actuating shaft that extends transversely relative to the cable and has an end portion that is remote from the cable and is engageable by a tool to rotate the actuating shaft; a safety catch including an arm pivotally mounted on the body, the arm being biased to a catch position in which the arm is located to catch the winch cable device, the safety catch including a release member attached to the arm and adjacent to and supporting the shaft, the release member extending to a position adjacent said end portion of the shaft so as to be engaged, in use, by the tool and moved thereby axially relative to the shaft to move the arm, against the bias, to a position in which the arm is displaced from the catch position; and guide means for mounting remote from the body for slidably receiving and supporting the release member.

2. The winch of Claim 1, wherein the release member extends substantially to the end of the shaft that is remote from the cable.

3. The winch of any preceding Claim 1 or 2, wherein the release member includes a sleeve surrounding the shaft.

4. The winch of any preceding claim, wherein the release member is integrally moulded with the arm.

5. A winch substantially as herein described with reference to Fig 3.