GB2136393A - Vehicle jack - Google Patents

Abstract

A jack has a support leg (11) on which is pivoted an arm (20) and a screw (25) extends between pivot points (23, 31) on the leg and the arm, the pivot point (23) being defined by a nut (24), so that turning of the screw by a handle (26) brings the arm towards the leg. The arm carries a load shoe (40) having an inverted U-shaped member (41), pivoted at the pivot point (31), and a load-engaging formation (42). An integral portion (46) of the member (41) extends down between the legs of the U and has an aperture (47) receiving the screw, so that the screw controls pivotting of the shoe. Flanges (48) engage the pivot member (31) and a shoulder (47) engages the portion (46) to strengthen the connection. <IMAGE>

Description

SPECIFICATION Vehicle jack This invention relates to a vehicle jack of the type having a support leg provided with a foot, an arm pivoted on the leg, a load-engaging shoe on the arm, a nut on the arm or the leg, and a screw member engaged with the nut and connected between the arm and the leg for raising the arm relative to the leg.

Jacks of this type usually have an arm which projects from only one side of the leg, although it is also known to extend the arm, so that the extended arm and the leg define a scissor arrangement. The first type is disclosed in U.K.

Patent Specification No. 1454847 and the second type is disclosed in U.K. Patent Specification No.

1011933.

The load-engaging shoe takes many different forms according to the formation on the vehicle, which the shoe engages in use. It is common for the shoe to be provided with a channel member for receiving a welded flange of a vehicle body. It is also common for the shoe to be pivoted on the arm to allow angular movement of the arm relative to the shoe, as the jack is being operated with the arm moving towards the leg.

To improve stability, it has previously been proposed to control the pivoting movement.

German AS No. 2621425 discloses an arrangement in which the screw and the shoe are pivoted to the arm by a common pivot pin and a very large shoe is provided, which extends along the screw and is also pivoted to the screw at another location, so that a constant angular relationship is maintained between the screw and the shoe.

The present invention provides an arrangement in which the relationship of the shoe to the screw is maintained and in which the shoe has a particularly simple construction, which can be cheaply produced.

In accordance with this invention, a vehicle jack comprises a support leg provided with a foot, an arm pivoted on the leg, a load-engaging shoe on the arm, a nut on the arm or the leg, a screw member engaged with the nut and connected between the arm and the leg for raising the arm relative to the leg, the shoe comprising a unitary metal pressing of inverted U-section with a portion integral with the base of the U and extending laterally relative to the planes of the legs of the U, pivot means pivotally mounting the legs of the U and the screw member on the arm for angular movement about a common axis, said portion of the shoe having an aperture through which the screw member extends, and a formation on the base of the U for engaging a formation on a vehicle.

The formation on the shoe is preferably defined by a separate member in the form of a metal pressing defining a channel for engaging with the formation of the vehicle, the separate member having crimped tabs securing the member to the base of the U of said unitary metal pressing. The separate member may be of sinuous form.

It is preferred that said portion of the shoe is reinforced by means of an abutment on the screw member at one side of said portion and by a projection on said portion extending to the oppostie side of said portion and engaging with the pivot means. It is also preferred that a pair of such projections are provided and defined by integral portions of said unitary metal pressing.

The abutment on the screw member may be in the form of a collar.

Reference is now made to the accompanying drawings, wherein: Figure 1 is a side elevation of a jack according to the invention; and Figure 2 is a perspective view of a detail of the jack showing the load-engaging shoe.

The jack shown comprises a leg 11 of channel shape having a cranked portion 12 defining a foot.

The base 13 of the foot is shaped to define first and second relatively angled support surfaces 14, 1 5. The first support surface is operative at the initiation of a jacking operation and the jack rolls onto the second support surface when the jack is under load.

Between the ends of the leg, an arm 20, also of channel form, extends into the channel of the leg and is pivoted thereto by a pin 21. The upper end of the leg has a slot 22 in each side wall of the channel in which are pivotally received trunnions 23 of a nut 24, housed between the channel side walls. A screw member 25 engages in the nut and is pivotally mounted at one end of the arm. At the other end, the screw member carries a handle 26, which is pivotally mounted to permit movement to a stowed position.

The screw member 25 extends through a pivot member 30 which is pivotally mounted by trunnions 31 in the channel sides of the arm 20.

The end of the screw member is provided with a bearing arrangement 32, which bears on the pivot member 30.

A load-engaging shoe 40 is mounted on the free end part of the arm 20. The shoe includes a main member 41 in the form of a unitary metal pressing. This main member is of inverted Usection and accommodates the width of the arm 20 between the legs of the U. The trunnions 31 extend through these legs 40a, 40b to pivot the shoe as well as the screw member on the arm 20.

The base 40c of the U carries a sinuous member 42. The ends of this member have tabs 43 which extend through slots in the base 40c and are crimped to secure the sinuous member 42 to the main member 41. The sinuous member defines a channel 44 for engaging with a flange on a vehicle.

The main member 41 includes a wall portion 46 which is an extension of the base 40c but at approximately 900 to the base. The wall portion 46 extends laterally between the planes of the legs 40a, 40b and parallel to the axis of the pivot member 30. The wall portion 46 has an aperture, which loosely receives the screw member 25 extending through the wall portion. This arrangement maintains the angular relationship of the shoe relative to the screw, such that the longitudinal axis of the screw member is perpendicular to a plane extending through the axis of the pivot member 30 and the centre line of the channel 44.

To support the wall portion 46, there is provided a collar 47 on the screw member, which collar abuts one side of the wall portion. The wall portion is supported on the opposite side by projections 48 extending from the wall portion and abutting the pivot member 30. the projections are integral parts of the unitary metal pressing and project from opposite side edges of the wall portion 46.

Claims (6)

1. A vehicle jack comprising a support leg provided with a foot, an arm pivoted on the leg, a load-engaging shoe on the arm, a nut on the arm or the leg, a screw member engaged with the nut and connected between the arm and the leg for raising the arm relative to the leg, the shoe comprising a unitary metal pressing of inverted U section with a portion integral with the base of the U and extending laterally relative to the planes of the legs of the U, pivot means pivotally mounting the legs of the U and the screw member on the arm for angular movement about a common axis, said portion of the shoe having an aperture through which the screw member extends, and a formation on the base of the U for engaging a formation on the vehicle.

2. A vehicle jack according to Claim 1, wherein the formation on the shoe is defined by a separate member in the form of a metal pressing defining a channel for engaging with the formation on the vehicle.

3. A vehicle jack according to Claim 2, wherein the separate member has crimped tabs securing the member to the base of the U of said unitary metal pressing.

4. A vehicle jack according to Claim 1, 2 or 3, wherein said portion of the shoe is reinforced by means of an abutment on the screw member at one side of said portion and by a projection on said portion extending to the opposite side of said portion and engaging with the pivot means.

5. A vehicle jack according to Claim 4, wherein a pair of said projections are provided and defined by integral portions of said unitary metal pressing.

6. A vehicle jack constructed substantially as herein described with reference to the accompanying drawings.