GB2311052A - Support for a spare wheel using two parallel cables - Google Patents

Abstract

A winching device for supporting a spare wheel beneath a vehicle body comprises a wheel-engageable support 111 and a winch mechanism comprising a pulley wheel 140 having at least two peripheral annular channels 143a, 143b and at least two cables 121a, 121b received in the respective channels, whereby the support is held by each cable so that the support is still held if one cable fails. The support comprises a tubular member 113 having a shoulder 119, a bearing member slidable in the tubular member and a compression spring 116 in the tubular member between the shoulder and the bearing member. The two cables extend through the tubular member and carry respective bearing heads 122a, 122b which bear on the bearing member. A cable guide 300 may be provided adjacent the pulley wheel.

Description

WINCHING DEVICE This invention relates to a winching device, in particular a winching device for carrying a vehicle spare wheel.

In some vehicles, it is usual to support a spare wheel beneath the body of the vehicle. The spare wheel is held, in a stowed position, with the tyre pressed against formations of the body, by means of a winching device holding a single support cable for the spare wheel under tension.

The winch can be operated, by means of a detachable handle, to lower the spare wheel on the cable to an accessible position. The device includes a pulley mounted to a bracket, the cable being wound on the pulley.

The winching device incorporates an eccentric gear mechanism, which provides a self-locking action, whereby a force exerted on the cable should not cause rotation of the pulley. The pulley should be rotatable only by rotation of an actuating shaft, designed to be engaged by the handle.

Winching devices of this type are disclosed in GB-A-1506244, GB A-2235911, US-A-4625947 and EP-A-0491513.

In addition to the self-locking gear mechanism, EP-A-0491513 discloses a safety arrangement for preventing the stowed wheel from accidentally falling to the ground if suspension by the cable accidentally fails (e.g. the cable snaps).

The safety arrangement comprises a safety hook pivotally connected to the bracket and gravitationally urged to a position such that if the cable accidentally breaks, the hook prevents the wheel from falling to the ground.

The hook is automatically released by engagement of the gear mechanism with the handle to actuate the mechanism.

Although this safety arrangement works well, it is relatively expensive and therefore increases the manufacturing costs of the winching device.

It would be desirable to provide a winching device that is cheaper, and yet still has a safety device for preventing a wheel from being released into a dangerous state, if cable suspension fails.

US-A-3952894, published 1976, discloses a winch comprising a rotatable shaft, provided with three axially spaced flexible cables having end hooks for attachment to at spaced points around a wheel. It is clear that, if any one cable broke, the wheel would be released and no safety device is provided.

US-A-4029297, published 1977, discloses a winch comprising two radially spaced independently mounted pulley wheels and two respective winch cables for holding a load at spaced points. The pulley wheels are driven by a common drive, but they are interlinked, so that one can be driven without the other to adjust one of the cables relative to the other for maintenance of balance.

This arrangement is very expensive and clearly unsuited to the mounting of a vehicle wheel. It would also provide an unbalanced load, if a cable were to break.

The present invention provides a winching device comprising a winching device for supporting a spare wheel beneath a vehicle body, the device comprising a wheel-engageable support, including a tubular member having a shoulder, a bearing member slidable in the tubular member, compression means in the tubular member between the shoulder and the bearing member, at least two parallel winch cables extending through the tubular member and carrying respective bearing heads which bear on the bearing member, a winch mechanism comprising a pulley wheel having at least two peripheral annular channels, the cables being secured to the pulley wheel and received in the respective channels, whereby the support is held by each cable, so that the support is still held if a cable fails, the winch mechanism including actuable means and gear means for rotating the pulley wheel to raise or lower the support by means of the winch cables, the bearing head and the bearing member, the winch mechanism including a locking mechanism for resisting reverse rotation of the pulley.

Reference will now be made to the following figures in which: Fig 1 is a side sectional view of the winching device of EP-A-0491513; Fig 2 is an exploded view showing the eccentric gear mechanism and pulley of the device of EP-A-0491513; Fig 3 is a side sectional view of the preferred embodiment of a winching device of the present invention; and Fig 4 is an exploded view showing components of an eccentric gear mechanism and pulley of the device of Fig 3.

Referring now to Figs 1 and 2, there are shown parts of the prior art winching device of EP-A-0491513, the disclosure of which is incorporated herein by reference. Details of the support frame and eccentric gear mechanism disclosed in this document apply in particular to the preferred embodiment of the winching device of the present invention.

Briefly, the prior art device includes a pulley 40 formed from rivetted parts to define first and second sides 41,42 with an annular channel 43 therebetween. A first gear 45 is secured to the first side 41 of the pulley and has a central aperture defined by internal gear teeth 46.

The pulley is rotatably mounted on a pin defining a hub 48.

The first gear forms part of an eccentric gear mechanism including a second gear 50, having outer gear teeth 51, and rotatably mounted on an eccentric part 52 of a drive member 53. The drive member has a noncircular hole 54, with flats, and is non-rotatably engaged on a corresponding part 55 of the hub 48.

The gear mechanism includes a torque plate 56 having an aperture 57 formed complementary to the second gear and receiving this gear, so that the torque plate is non-rotatably connected to the gear. The torque plate has an arm 58, whose end is formed with an elongate slot 60, extending radially of the second gear 50. The slot engages with a rivet 61 secured to a support body 25.

Rotation of the hub 48 causes rotation of the drive member 53 with accompanying eccentric motion of the eccentric part 52. The torque plate 56 prevents rotation of the second gear 50, so that the first gear 45 is caused to rotate around the second gear. This motion causes rotation of the pulley 40 and winding of the cable 21 on the pulley. The torque plate resists rotation of the pulley 40 under the force exerted by tension in the cable 21.

The rivet 61 is one of four bolts or rivets 61 to 64 used to secure a casing 65 to the support body 25.

The hub 48 is located between the back of the support body 25 and an apertured block 70 on the front of the casing 65, by a flange 48b. The block has a non-circular socket 71 for receiving an insertable tool (not shown) for rotating the block 70. The block is mounted on the noncircular part 55 of the hub 48, so that the hub is also rotated, the block defining actuating means. The block carries a flared guide 72 to assist location of the tool.

A spring 90 is provided. This is a bent wire spring having an eye 91 at one end. The opposite end forms a loop 92 from which a free end portion 93 extends. The eye 91 engages one of the casing rivets 63 and the loop engages another casing rivet 64 to hold the spring in position in the casing 65.

The free end portion 93 resiliently engages the torque plate 56 and urges the first gear 45 into mesh with the second gear 50. This arrangement takes up tolerances in the construction and ensures that vibration does not cause any reverse motion of the gears, with consequent release of tension in the winch and release of a spare wheel, in use.

A safety arrangement is also provided in the prior art device. This comprises a safety hook 80 pivoted at 81 to the bracket 25 and gravitationally urged to hook-engage in an aperture 82 in the tube 13 of the suspension device. If suspension by the cable 21 fails, the hook prevents the suspension device from falling. An aperture 83 in the sleeve 31,35 permits engagement of the hook with the tube. The hook is gravitationally urged to the engagement position.

The hook is automatically released by insertion of the tool to actuate the mechanism. The hub 48 has an axial bore slidably receiving a release pin 85, which extends into the socket 71. The pin engages the hook 80 and is urged by the tool to pivot the hook out of engagement with the tube.

In the prior art winch a single cable 21 is attached to the pulley, within the channel 43, and is wound on the pulley in order to tension the cable.

The present invention, on the other hand, has a pulley (Figs 3 and 4) having two axially adjacent, peripheral channels 143a, 143b, each receiving a respective cable 121a, 121b that is attached at one of its ends to the pulley 140. The parallel cables pass through a bearing member 112 and the opposite end of each cable 121a,121b has a bearing head 122a, 122b bearing on the member 112. The bearing member is slidable in a tubular member 113 attached to a support plate 111 for securance to a vehicle wheel. The tubular member 13 has a shoulder 119 and a compression spring 116 extends between the shoulder and the bearing member. The cables extend through the tubular member and the bearing member. The cables thereby resiliently support a vehicle wheel by means of the bearing heads 122a, 122b, the bearing member 112, the spring 116, tubular member 113 and the support 111.

The cables 121a, 121b extend through respective, adjacent apertures 200a,200b in a guide plate 300 adjacent to the pulley wheel 140. The cables 121,121b are of the same length and each cable 121a,121b is sufficiently strong to support the weight of the carrier plate 111 and a spare wheel by itself.

The winch of the present invention avoids the need to use a complex hook and catch safety arrangement as in the prior art device.

Instead, the safety feature is provided by the two cables 121a,121b. If one of the cables 121,121b breaks or becomes detached from its pulleys when a wheel is carried by the plate 111 in a stowed (i.e. winched) position, the wheel will remain in a secure position because it remains suspended from the winch, in the stowed position, by the other cable.

Although two cables have been shown, it is possible to provide more cables, e.g. three, so that if one cable breaks, the other two cables can support the weight of the wheel and plate. The latter two cables can have a combined strength that enables the cables to support the weight between them. Alternatively, each cable can have sufficient strength to support the weight by itself.

Claims (3)

1. A winching device for supporting a spare wheel beneath a vehicle body, the device comprising a wheel-engageable support, including a tubular member having a shoulder, a bearing member slidable in the tubular member, compression means in the tubular member between the shoulder and the bearing member, at least two parallel winch cables extending through the tubular member and carrying respective bearing heads which bear on the bearing member, a winch mechanism comprising a pulley wheel having at least two peripheral annular channels, the cables being secured to the pulley wheel and received in the respective channels, whereby the support is held by each cable, so that the support is still held if a cable fails, the winch mechanism including actuable means and gear means for rotating the pulley wheel to raise or lower the support by means of the winch cables, the bearing head and the bearing member, the winch mechanism including a locking mechanism for resisting reverse rotation of the pulley.

2. A winching device according to Claim 1, including a cable guide member adjacent to the pulley wheel and having adjacent apertures receiving the parallel cables.

3. A winching device substantially as herein described with particular reference to Figs 3 and 4 of the accompanying drawings.