ZA201002968B

ZA201002968B - Wrench

Info

Publication number: ZA201002968B
Application number: ZA2010/02968A
Authority: ZA
Inventors: Anthony Kolb Lloyd
Original assignee: Anthony Kolb Lloyd
Priority date: 2010-01-22
Filing date: 2010-04-28
Publication date: 2012-01-25

Description

; Hii 20 “~ FIELD OF THE INVENTION U1 0 / 0 2 66 9

This invention relates to a wrench or spanner and is particularly concerned with a spanner of the ring type.

BACKGROUND OF THE INVENTION

The conventional ring spanner has the frustrating problem of slipping down the nut or bolt head being tightened or loosened, and more particularly when the tightening or loosening operation is relaxed — when the ring has to be re-aligned with the head in order to draw it up the head again.

Although the conventional ring spanner has a twelve-pointed star internal configuration and thus fits most heads at their corners, there are heads that do not conform with the twelve star configuration and the spanner slips.

It is an object of the present invention to provide a simple wrench that can be used as a wrench or as a ring spanner in many circumstances.

THE INVENTION

According to the invention a wrench includes a handle and an end formation in the form of a ring or open spanner, the end including a spring-loaded pawl adapted to engage a surface of a nut or bolt head and to impart torque for the head to be rotated in a desired direction.

The end formation of the wrench of the invention may preferably comprise a simple ring with a plain inner wall, as distinct from a conventional twelve point ring spanner end formation, or other configurations. This reduces costs of manufacture substantially.

In a preferred form of the invention the pawl is set at an angle to a radius of the end of the wrench or spanner according to the direction required. An angle of 45 degrees to the radius extending through the longitudinally axis of the wrench is preferred. :

‘v i } The wrench may have a slot for accommodating the pawl, the slot including a shoulder or like formation to prevent the pawl exiting the slot under the pressure of the spring.

The slot may be formed during a drop forging manufacturing process and extends inwardly from the outer surface to a position short of the opposite surface. A simple swivelable or the like cover plate may be provided to prevent slipping of the pawl from the slot. in a preferred form of the invention a tool is provided that has its ends as described above in opposite senses — one end for tightening and one end for loosening.

A tool set may be provided with different diameters as with conventional ring spanners except that both ends will be of the same diameter.

The pawl can have a substantial length in the vertical plane having regard to the axis of the tool, consistent with its containment in the slot. The greater the length the greater the torque that can be generated because of the larger contact intersurface involved between the edge of the pawl and the surface of the nut or bolt head.

EMBODIMENT OF THE INVENTION

An embodiment of the invention is described below with reference to the accompanying drawings, in which:

Figure 1 is a cross sectional side view of an end of a wrench according to the invention,

Figure 2 is a plan view thereof, and

Figure 3 is a plan view of a wrench with opposite ends.

In the drawings, an end of a wrench is plain circular and has a slot 10 formed into the end. The slot receives a spring-loaded pawl 12, the spring being indicated by reference 11.

. / ¥ ’ The slot is formed with shoulder 14 that limits the exit of the pawl so that it is not fully ejected by the spring. A swivelable plate 16 may be provided to prevent the pawl : from falling out of the slot.

In use the pawl will abut one vertical side of a hexagon or other shaped nut or bolt head.

It will be appreciated that the tool incorporating the invention may be used as a ratchet wrench.

In Figure 3 the arrangement is repeated at the other end of the wrench, the location of the pawl being in the opposite sense so that the wrench can be used at one end for tightening and the other for loosening.

Claims

CLAIMS: cL

1. A wrench including a handle and an end formation in the form of a ring or open spanner, the end including a spring-loaded pawl adapted to engage a surface of a nut or bolt head and to impart torque for the head to be rotated in a desired direction.

2. The wrench according to claim 1 in which the end formation comprises a simple ring with a plain inner wall.

3. The wrench according to either of the above claims in which the pawl is set at a predetermined angle to a radius of the end of the wrench or spanner according to the direction required.

4. The wrench according to claim 3 in which the angle is of the order of 45 degrees to the radius extending through the longitudinally axis of the wrench.

5. The wrench according to any of the above claims which has a slot for accommodating the pawl, the slot including a shoulder or like formation to prevent the pawl exiting the slot under the pressure of the spring.

6. The wrench according to claim 4 in which the slot is formed from one surface to a position short of the opposite surface.

7. The wrench according to claim 6 in which a swivelable or the like cover plate is provided to prevent slipping of the pawl from the end.

8. A wrench according to any of the above claims in the form of a tool that has its ends in opposite senses — one end for tightening and one end for loosening.

9. A set of tools according to any of the above claims with different diameters.

10. The wrench according to any of the above claims in which the pawl has a substantial length in the vertical plane having regard to the axis of the tool, consistent with its containment in the slot. Dated this 20 day of April 2010 MORRISON FORSTER INC. APPLICANTS’ PATENT ATTORNEYS