GB2306936A

GB2306936A - A winch assembly with safety catch

Info

Publication number: GB2306936A
Application number: GB9623180A
Authority: GB
Inventors: Stephen Broadstock
Original assignee: Metallifacture Ltd
Current assignee: Metallifacture Ltd
Priority date: 1995-11-11
Filing date: 1996-11-06
Publication date: 1997-05-14
Anticipated expiration: 2016-11-06
Also published as: GB9623178D0; GB9623180D0; GB2306936B; GB2306935B; GB2306935A; GB9523143D0

Description

1 2306936 1 VEHICLE WHEEL SUSPENSION ASSEMBLY This invention relates to a

vehicle wheel suspension assembly for use with a winching mechanism, wherein the assembly includes a winch cable for suspending a vehicle spare wheel, and a safety catch to prevent lowering of the wheel from a stowed position if the suspension by the cable fails.

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 the suitable position for 2 stowing the spare wheel. This makes access to the winching mechanism difficult.

The present invention enables, when required, mounting of the winching mechanism on the vehicle at a location remote from the spare wheel.

The present invention provides a vehicle wheel suspension assembly for use with a winching mechanism, the assembly comprising a body, a winch cable device including a winch cable, suspension means for suspending a vehicle wheel from the cable, the cable being connectable with a winching mechanism for raising the wheel to, or lowering the wheel from a stowed position, and 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 arm being engaged by the winch cable device which holds the arm against the bias, in a position in which the arm is displaced from the catch position, the arm being movable to the catch position under said bias, if suspension by the cable fails.

The present invention enables the winching mechanism to be mounted at a location remote from the spare wheel, since the winch cable can be routed, e.g. over a pulley, away from the location of the spare wheel to the remotely located winching mechanism, and physical contact of the tool with the catch as in the prior art is not required to move the catch from the operational position. Instead, the cable normally holds the catch away from this position.

Reference is now made to the following figures in which:

3 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, 5 but in die operational position; and Figure 3 shows a winch having a vehicle wheel suspension assembly in accordance with an embodiment of the present invention.

The vehicle wheel suspension assembly shown in Fig 3 forms part of a winch substantially as disclosed in EP-A-0612653.

The winch 10 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 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 4 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.

The catch part of the winch is modified according to the present invention, as shown the winch 100 in Fig 3. A vehicle spare wheel 160 is shown suspended from the cable 114 by a bracket 111 in a manner similar to that of Figs 1 and 2.

The modified safety catch includes a cranked arm 125 pivotally mounted to the housing at a pivot point 126 and projecting through an opening 170 in the housing wall 124. A roller 127 is rotatably provided at an end part of the arm 125 and the arm is formed into a hook 129 at the opposite end part of the arm. The roller engages the cable 114, and the hook.129 faces the cup-shaped plate 119.

A spring 140 biases the arm 125 to the position shown in phantom in Fig.3, in which the hook 129 is in a catch position, to catch a peripheral part of the dome washer 119. The arm is, however, held against the bias so that the hook 129 is in a retracted position. The tensioned cable 114 is engaged by the roller 127 to hold the arm against the bias in this retracted position, in which the hook 129 is free of the plate 119 (solid line in Fig.3).

If suspension of the wheel by the cable 114 fails because the cable breaks (phantom line in Fig. 3) or becomes disconnected from the winching mechanism while the wheel 160 is stowed under the vehicle chassis, the tension on the cable 114 is released. The arm 125 is then no longer held against the bias, and the arm 125 automatically moves under the action of the spring 140 to the catch position in which the hook 129 can catch the plate 119 (phantom line in Fig.3), thereby acting as a safety catch to prevent the spare wheel from dropping to the ground.

The assembly of the present invention has the advantage that the operation of the safety catch is not dependent on the siting of the winching mechanism. Preferably the winching mechanism is mounted on the vehicle at a location remote from the assembly housing, but it is also contemplated that the safety catch and winching mechanism can be provided in the same housing.

As an alternative (not shown) to engaging the roller 127 with the cable 114, the roller could engage part of the guide assembly, which may be modified to facilitate engagement with the roller.

In this embodiment, the arm is biased to the engaged position by 30 gravity and it is envisaged that the spring 140 may be omitted.

6

Claims

1. A vehicle wheel suspension assembly for use with a winching mechanism, the assembly comprising a body, a winch cable device including a winch cable, suspension means for suspending a vehicle wheel from the cable, the cable being connectable with a winching mechanism for raising the wheel to, or lowering the wheel from a stowed position, and 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 arm being engaged by the winch cable device which holds the arm against the bias, in a position in which the arm is displaced from the catch position, the arm being movable to the catch position under said bias, if suspension by the cable fails.

2. The assembly of Claim 1 wherein the arm is held out of the catch position by engagement with the cable.

3. The assembly of Claim 2 wherein the arm includes a roller which engages with the cable.

4. The assembly of Claim 3 wherein the arm is cranked, the roller is located on an end part of the arm and the opposite end part is formed as a catch portion.

5. The assembly of any preceding claim, wherein the winch cable device includes a guide means for guiding the cable on the body during raising and lowering of the wheel, the arm being located in the catch position to catch the guide means.

6. A vehicle wheel suspension assembly according to any preceding 7 claim, in combination with a winch mechanism to which the winch cable is attached.

7. A vehicle winch assembly substantially as herein described with reference to Fig.3.