GB2146931A - Tool for use in tightening and releasing sunken nuts - Google Patents

Abstract

Sunken nut 16 is tightened onto shaft 30 by inserting plate-like portion 12 of tool 10 between one flat side of the nut 16 and the confronting surface of surrounding hub 28 (e.g. on a commercial vehicle wheel) and turning the tool 10 by means of a socket spanner 24, 26 applied to hexagonal boss 22, the portion 12 turning the nut 16 by pressure on corner 14 as a result of reaction of the tool 10 with the surrounding hub structure. Release of the nut 16 is achieved by corresponding turning of the tool 10 in the opposite direction. The surface of the plate-like portion 12 facing the hub wall may be convex and reversal of the tool then permits expansion of the range of sizes with which the tool can be employed. Other arrangements may be provided for permitting the tool to be turned. <IMAGE>

Description

SPECIFICATION Tool for tightening and releasing sunken nuts This invention relates to a tool for tightening and releasing sunken nuts.

The term sunken nut as used in the present specification means, for example, a nut used in relation to a hub of a commercial vehicle which for securing such hub to a respective end of an axle of the vehicle the nut, when in position, being surrounded by the open end of the hub so that it is difficult to engage the nut with a conventional open-ended or ring spanner, an adjustable wrench or the like.

Normally such nuts are tightened or released by use of tubular spanners such as so-called "boxspanners". Box spanners are unwieldly. They are costly items to purchase and wide range of them are necessary to cope with different sizes of nut.

Moreover, they are not very strong.

It is an object of the present invention to provide a tool which is inexpensive to produce, which is easy to use, and which can cope with sunken nuts of various sizes.

With this object in view the present invention provides a tool for tightening and releasing sunken nuts comprising a plate-like portion fir engaging respective faces of the nut and the hub surrounding the same and, projecting from said plate-like portion, a protrusion by means of which the tool can be engaged to enable the plate to be twisted so as to apply a tightening or releasing movement of the nut by reaction against the hub.

Advantageously, the protrusion is a boss formed integrally with the plate to project approximately from the middle of one edge of the plate-like portion.

This boss may be formed so as to receive a laterally-projecting bar. Alternatively it may be hexagonal or other suitable shape to enable a handled socket to be fitted thereto.

The invention will be described further, by way of example, with reference to the accompanying draw ings, it being understood that the following description is illustrative and not limitative of the scope of the invention. In the drawings: Figure 1 is a perspective view illustrating a preferred embodiment of the tool of the invention.

Figure 2 is a perspective view illustrating the tool of Figure 1 introduced into a wheel hub of a commercial vehicle and a laterally-extending bar or wrench about to be fitted thereto; Figure 3 is a part-sectional elevation corresponding to the line Ill-Ill of Figure 2 and illustrating how the tool is used for tightening a sunken nut within the hub; Figure 4 is a view similar to Figure 3, but illustrating the use of the tool to release the nut; Figure 5is a view comparable with Figures 3 and 4 but illustrating the case where the same tool is used in connection with a smaller sunken nut having a greater clearance between it and the surrounding wheel limb; Figure 6 is a perspective view illustrating a second embodiment of the tool of the invention with its lateral barorwrench;; and Figures 7, 8and 9 are plan views illustrating three different modifications of the embodiment of the tool Figures 1 to 3, which three tools together may form a kit suitable for use in conjunction with a wide range of sunken nuts.

Throughout the various Figures of the drawings, similar reference numerals have been allocated to similar or comparable parts.

The preferred embodiment of the tool of the invention shown in Figures 1 and 2 indicated generally at 10 in the drawings, comprises a front plate-like portion 12 made of a suitable hard alloy such as nickel chrome. The plate-like portion 12 is intended to engage with a respective corner 14 of a nut 16 (see Figure 2) as will be described in more detail in due couse, and as will be seen it is generally rectangular in configuration with one face 18 substantially planar and its other face 20 convex.

Projecting rearwardly from said plate-like portion 12, approximately midway along one of its two sides or edges which increases and decreases in thickness by reason of the plate being convex on the face 20, is a protrusion 22 in the form of a boss which is, in the illustrated example, formed integrally with the platelike portion 12 by reason of the tool having been made by a forging operation. However, the boss 22 may, if desired, be made as a separate part of less expensive but equally strong material as the portion 12, secured to the latter by welding or casting-on.

The boss 22 is, as mentioned, arranged approximately midway along one side of the plate-like portion 12, but as shown it has an overall configuration of width less than the width of the plate-like portion 12 so that it does not overhang the side edges of the latter. Externally, the boss is hexagonal in configurat;on so that it can be engaged by means of a complementary socket 24 (see Figure 2) having a lateral rod or to bar 26 whereby a rotary force or torque can be applied to the tool 10.

The use of the tool for tightening the nut 16, which is sunken within hub 28 of a commercial vehicle wheel (the rest of which is not illustrated), is shown in Figures 1 and 3. In order to tighten the nut 16 on its axle 30 the plate-like portion 12 of the tool 10 is introduced between one of the flat sides of the nut 16 and the inside surface of the hub 28 with the plane surface 18 overhanging the clock-wise disposed corner 14 of said flat side and with the boss 12 protruding from the hub 28 as shown in Figures 2 and 3.

The socket 24 is now fitted to the boss 12 (as will be evident from Figure 2, and force is applied to the bar 26 so that the tool 10 is tended to be rotated about the central longitudinal axis of the box 22, but the effect is achieved, as shown in Figure 3, that the flat face 18 of the plate-like portion 12 pushes against the confronting flat face of the nut 16 and acts particularly against the corner 14, whilst the opposite convex face 20 of the plate-like portion 12 pushes against the inside of the hub 14. The resultant reaction provides leverage strong enough to turn the nut in the direction of the arrow 32 in Figure 3, sufficient to tighten the nut 16 on the axle 30 as strongly as may be required.

Naturally, release of the nut 16 can be achieved by application of anticiockwise force to the tool by way of the towing bar 26 and socket 24 when, as shown in Figure 3, the tool 10 will be shifted in the opposite direction as indicated by the arrow 34 in Figure 4 so as to engage with corner 36 of the nut 16, which corner 36 is next adjacent to the corner 14, thereby to impart an unscrewing movement to the nut 16.

Practical experience shows that very strong tightening on releasing forces can be achieved with the tool.

It will readily be appreciated, particularly from Figures 3 and 4, that the tool illustrated can be employed for tightening and loosening a range of sizes of nuts 16, the largest providing just a sufficient gap between itself and the interior wall of the hub 28 for introduction of the tool, whilst the smallest being such that the contact between the plate-like portion 12 and an associated corner of the nut 16 is adequate for applying a turning force to the nut 16 without spoiling its corners. As can be seen from Figure 5, a reversal of the disposition of the tool so that its planar surface 18facesthe innerwall ofthe hub and the convex surface 20 faces the nut 16 serves to widen the range of sizes of nuts 16 with which a single tool 10 will be effective.

The means provided for enabling the tool 10 to be turned does not have to be an arrangement providing a socket 24 fitting to a boss 22, and the arrangement may, as shown in Figure 6, be such that the boss 20 provided on the tool (either as a separate component or an integral component) is formed as a socket having a non-round (e.g. hexagonal) recess 40 for receiving one end of an angled to bar 42. In this embodiment the plate-like portion 12 is shown as a flat member, but this may be plane-convex as in the arrangement of Figures 1 to 5. Similarly, in the embodiment of Figures 1 to 5, the member 12 may be planar on both its main surfaces.

As has been illustrated generally in Figures 7,8 and 9, in practice it is generally only necessary to have three of the tools substantially of the form illustrated in Figures 1 to 5, each with a plate-like section of a different width, to be able to cope with substantially all of the usual different sizes of nuts on wheel hubs of conventional commercial vehicles.

This compares favourably with the great number of different sizes of box spanner, or of sockets for socket-type spanners, which would otherwise be needed.

The invention is not confined to the precise details of the foregoing and variations may be made thereto within the scope of the invention. Thus, for example, instead of the boss, the rearwardly extending protru sion may be formed by two spaced-apart extensions providing between them a substantially U-shaped gap into which a tool can be inserted for turning the tool of the invention. Other variations are possibie within the scope of the following claims.

Claims (9)

1. A tool for tightening and releasing sunken nuts comprising a plate-like portion for engaging respective faces on the nut and the hub surrounding the same and, projecting from the said plate-like portion, a protrusion by means of which the tool can be engaged to enable the plate to be twisted so as to apply a tightening or releasing movement of the nut by reaction against the hub.

2. A tool as claimed in claim 1 in which the protrusion is a boss formed integrally with the plate to project approximately from the middle of one edge of the plate like portion.

3. A tool as claimed in claim 2 wherein the boss is formed so as to receive a laterally-projecting bar.

4. A tool as claimed in claim 3 wherein the boss is externally hexagonal to enable a socket to be securedly fitted thereto.

5. A tool as claimed in claim 3 wherein the boss has a non-round recess to receive a lateral towing bar.

6. A tool as claimed in any preceding claim wherein he plate-like portion is substantially planar on one fade and is convex on its opposite face.

7. Atool for tightening and releasing sunken nuts substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 5 in Figure 6, in Figure 7, in Figure 8, or in Figure 9 of the accompanying drawings.

8. A set of tools for tightening and releasing sunken units as claimed in claim 1 and characterised in that the plate-like portions of the tools are of different widths.

9. A set of tools for tightening and releasing nuts substantially as hereinbefore described with reference to and as illustrated in Figures 7,8 and 9 of the accompanying drawings.