GB2454505A

GB2454505A - Spanner with ratchet mechanism

Info

Publication number: GB2454505A
Application number: GB0722029A
Authority: GB
Inventors: Barry John Kittow Roberts
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-11-09
Filing date: 2007-11-09
Publication date: 2009-05-13
Also published as: GB0722029D0

Abstract

The spanner 10 includes a handle portion 11 conjoined to a head portion having an opening 17 adapted to receive a nut 30 to be rotated. At least two moveable members 21 project into the opening, each positioned adjacent an abutment 27. Each moveable member 21 is adapted to engage with the nut 30 when received in the opening 17. Turning of the spanner 10 relative to the nut 30 in one direction moves each moveable member away from its respective abutment, allowing the spanner to turn relative to the nut. However, turning of the spanner in the other direction relative to the nut causes each moveable member 21 to engage the nut 30, and prevent relative turning of the nut relative to the spanner by each moveable member 21 pressing against an abutment 27. The moveable members 21 may be spherical and held within the opening by a retainer. The head of the spanner may have two opposed jaws 13, 14.

Description

SPANNER

The present invention relates to spanners, and in particular a spanner with a ratchet mechanism.

Spanners with ratchet mechanisms are known, for example GB 865,800, discloses an open-ended spanner with a spring-loaded depressible pawl enabling the spanner to be rotated in one direction relative to a nut or bolt-head. A similar device is disclosed in US 5,533,428. US 2,712,259 also discloses an open-ended ratchet spanner with a plurality of spring-loaded pawls, each adapted to engage with a different corner on the nut or bolt-head.

The spring-loaded pawl mechanism used on all three of these prior-art spanners is flawed, and is likely to become damaged or corroded through repeated use. Further, the mechanism is liable to get clogged up with dirt and grease and fail to function properly. The prior art spanners described herein all require a significant number of components, which add to the complexity and therefore cost of their manufacture. As such, none of these devices are effective, and are not available on the market despite having been disclosed as far back as the early 1950's.

The present invention overcomes the disadvantages of the prior art by providing a spanner with a ratchet mechanism that is easy to produce, and is able to withstand heavy use and exposure to dirt and grease without affecting the operation of the mechanism. Furthermore, the relative simplicity of the design of the present invention as compared to the prior art spanners means that cost to manufacture will be reduced. The prior art spanners, due to the presence of small items such as springs integrated within the body thereof, would require high-precision methods of manufacture, which would not necessarily be required for the present invention. The spanner of the present invention could instead be relatively easily and inexpensively produced to a high standard in high volume by an automated assembly process.

According to the present invention there is provided a spanner with a ratchet mechanism, the spanner comprising: -a handle portion; -a head portion conjoined to the handle portion, the head portion having an opening adapted to receive a nut (as defined herein) to be rotated; -at least two moveable members projecting into the opening and each positioned adjacent an abutment, each moveable member being adapted to engage with the nut when received in the opening, wherein turning of the spanner relative to the nut in one direction moves each moveable member away from its respective abutment allowing the spanner to turn relative to the nut, but wherein the turning of the spanner in the other direction relative to the nut causes each moveable member to engage the nut, and prevent relative turning of the nut relative to the spanner by each moveable member pressing against the abutment.

The spanner of the present invention is primarily to be used to tighten or loosen standard hexagonal nuts or bolt-heads (though reference hereinafter will only be made to nuts, both are encompassed as well as anything equivalent), with spanners provided in a range of sizes for different sizes of nut. Of course, a spanner according to the present invention can be adapted for use with nuts or bolt-heads having any number of side faces by increasing the number of abutments and troughs accordingly. Preferably, the opening on the head portion of the spanner will have a profile that corresponds substantially to the shape of the nut or a portion thereof so that the nut may be engaged therein.

In use, when rotated in one direction the moveable members each engage with a separate corner of the nut when the spanner is being rotated relative to the nut, and the moveable member is held in place by being forced against the abutment. When the spanner is rotated in the other direction, the moveable members are moved out of the way by the corners of the nut, so that they pass thereover. Therefore, it is preferred that adjacent each abutment is a trough into which the moveable members can be moved by the nut. Preferably, the abutments and the troughs are formed in the head portion of the spanner.

The shape of the abutments must be suitable to stop the moveable members and prevent them from passing thereover. Ideally the abutments will comprise a flat or slightly concave surface and be positioned substantially perpendicularly to the direction of force of the moveable members when pushed thereagainst. The abutments and troughs within the opening may be produced in a number of ways, such as by moulding or by machining a suitable profile into the spanner head portion during manufacture, Of course, any suitable configuration of abutment and trough which enables the moveable members to be held in place by the nut during rotation in one direction, and be moved out of the way during rotation in the other direction is within the scope of the present invention. Most conveniently each abutment may be formed as one end of the trough.

Preferably the moveable members have rounded edges, because the rounded edge allows the corner of the nut easily to pass thereover in one direction. Spherical balls made from a suitable material such as metal have been found to offer the correct characteristics, Of course, any suitable alternative could be used.

The moveable members are preferably held in place by a retainer in the form of an elongate strip. The retainer is preferably located within the opening, and has an aperture through which part of each moveable member extends, so that they may engage with the nut. So that they will easily engage with the nut, the moveable members are advantageously positioned, before engagement with the nut, next to the abutment and protruding through the aperture. At this position the moveable members are extended inwards i.e. towards the nut, by the greatest amount. The retainer preferably has biasing means, which bias the moveable members to the position against the respective abutment. These biasing means will preferably comprise a resilient tongue portion. This tongue is flexible enough to allow the moveable members to be displaced away from the respective abutment by the corner of the nut. In a preferred embodiment, the tongue is cut from the elongate strip, with the ensuing gap forming the aperture. Any suitable biasing means could be used as an alternative, for example by providing a resilient material such as foam within the trough.

In a preferred embodiment the head portion of the spanner comprises two opposed jaws, which extend to define a nut receiving region and a throat.

The throat allows passage of the nut therethrough into the nut receiving region, rather than the spanner having to be passed axially over the top of the nut, which can be awkward in a confined space. The nut receiving region is of sufficient size to allow free rotation of the nut relative to the spanner, subject to engagement with the moveable members. The throat will advantageously be slightly narrower than the nut receiving region, slightly wider than the distance between opposed side edges of the nut, but narrower than the distance between opposed corners thereof. This means the throat must be correctly aligned with the nut to allow it to pass therethrough to be received in the nut receiving region. Also it enables the throat to be used as a standard spanner should this be required.

The ratchet mechanism of the present invention could instead be applied to a closed-headed spanner.

Whilst a minimum of two abutments, moveable members and troughs are required to suitably engage the nut with the spanner, there is no upper limit on the number of these that can be provided. To ensure an optimum engagement between the spanner and the nut, the opening in the spanner will preferably have four abutments, each with associated moveable members and troughs, which will correspond to four of the corners of the nut. Alternatively, a spanner with a number of moveable members and abutments in excess of the number of corners on the nut could be provided, and this will mean that the user can rotate the spanner a shorter distance before the spanner will engage with a nut. The number of apertures in the elongate retainer will need to equate to the number of moveable members. Alternatively a separate retainer could be used for each moveable member.

So that the invention may be better understood, one embodiment thereof will now be described in detail, by way of example only, with reference to the accompanying drawings wherein: Figure 1 shows a view of the spanner of the present invention engaged with a nut, with the moveable members adjacent the abutments; Figure 2 shows the spanner of Figure 1 engaged with a nut where the corners of the nut are pushing the moveable members away from the abutments; Figure 3 shows the spanner engaged with a nut and with the moveable members recessed to permit rotation of the spanner relative to the nut; Figure 4 shows a perspective view of the retainer of the present invention; and Figure 5 shows the head of the spanner of the present invention without the retainer.

Referring simultaneously to all of the Figures, there is shown a spanner, generally indicated 10. As seen in Figures 1 to 3 in use the spanner can be used for tightening a nut, generally indicated 30. The spanner comprises a handle portion 11 and extending therefrom a head portion comprising opposed jaws 13, 14, which terminate in flat ends 15, 16 respectively. A nut receiving region 17 is defined between the jaws 13, 14, into which in use the nut 30 is received. The nut 30 is a standard hexagonal nut with six identical corners 31 and six identical side faces 32.

Within the nut receiving region 17 are four recesses defined in the spanner jaws 13, 14. Moveable members in the form of four metal spheres 21 are located one in each of these recesses and they are held therein by a retainer, generally indicated 22. These parts together define a ratchet mechanism. Figure 4 shows the retainer 22 in more detail, and it can be seen that the retainer 22 comprises a body portion 23 and end regions 26, the retainer 22 being made out of a flexible but strong metal or plastic material.

Formed by projections bent from the body portion 23 are four resilient tongues 24, and the formation of these creates apertures 25. The apertures 25 are of a size such that a part of each metal sphere 21 can protrude through said apertures 25, but will not completely pass therethrough. The tongues 24 bias the ball bearings 21 up into the aperture 25.

As is more clearly shown in Figure 5, the recesses within the nut receiving region 17 include abutments 27, trough portions 28, slots 29 (which receive the end regions 26 of the retainer 22), and a lip 33 which prevents the retainer 22 from sliding out. In use, when the metal spheres 21 are pushed up against the abutments 27 by the corners 31 of the nut 30, the metal spheres 21 are prevented from further movement in that direction and so the spanner is locked relative to the nut. The troughs 28 are substantially V-shaped and when a metal sphere 21 is pushed into the deepest part of a trough, there is enough room for the corners 31 of the nut 30 to pass unrestrained thereover.

As shown in Figure 1, the retainer 22 is held in place by insertion of the end portions 26 of the retainer 22 into the slots 29, such that the retainer 22 abuts the lip 33 which is on one side of the spanner head. Although not shown here, a plate or functionally equivalent device can be placed on the other side of the spanner head against the other edge of the retainer 22 to hold it in place.

The tongues 24 will bear on the ball bearings 21 and tend to urge then against the abutments 27.

In use, a nut can be located into the nut receiving region 17 by inserting the nut 30 between the jaws 13,14, which define a throat therebetween. The distance between the ends 15, 16 of the jaws 13, 14 is slightly greater than the width across opposed side faces 32 of the nut 30. The end faces 15, 16 can in fact be used to engage with the side faces 32 of the nut in order to rotate said nut 30.

As shown in Figure 1, when the spanner 10 is rotated clockwise (as shown by arrow 40), the corners 31 of the nut 30 engage with the metal spheres 21, which are prevented from further movement in that direction by the abutments 27. When in the position shown in Figure 1, a user will therefore be able to rotate the nut 30 in a clockwise direction.

Figures 2 and 3 show the effect of rotating the spanner 10 in an anticlockwise direction, as shown by arrow 41. When the spanner is rotated in an anti-clockwise direction, the corners 31 of the nut 30 move away from their contact with the metal spheres 21 as shown in Figure 1 and are free to rotate (with respect to the spanner) to the position as shown in Figure 2. The corners 31 then engage with the metal spheres 21, and when sufficient pressure is applied the metal spheres 21 are pushed back against the urging of the tongues 24 so that they sit deeper within the troughs 29. This movement is sufficient for the corners to pass over the metal spheres, as shown in Figure 3 and allow for the rotation of the spanner 10 without rotating the nut 30. Once the corners have passed over, the metal spheres 21 are urged back toward the abutments 27 by their associated tongue 24. Due the sloping nature of the base of each trough 28, as each metal sphere 21 moves toward the respective abutment 27 it projects further out of the trough 28.

To use the spanner of the present invention to rotate a nut in the other direction, the user simply has to turn the spanner over and use it the other way round.

Claims

1. A spanner with a ratchet mechanism, the spanner comprising: -a handle portion; -a head portion conjoined to the handle portion, the head portion having an opening adapted to receive a nut (as defined herein) to be rotated; -at least two moveable members projecting into the opening and each positioned adjacent an abutment, each moveable member being adapted to engage with the nut when received in the opening, wherein turning of the spanner relative to the nut in one direction moves each moveable member away from its respective abutment allowing the spanner to turn relative to the nut, but wherein the turning of the spanner in the other direction relative to the nut causes each moveable member to engage the nut, and prevent relative turning of the nut relative to the spanner by each moveable member pressing against the abutment.

2. A spanner as claimed in claim 1, wherein adjacent each abutment is defined by a side wall of the trough into which each moveable member can be moved to allow free rotation of the spanner relative to the nut or bolt-head in the one direction.

3. A spanner as claimed in claim 1 or claim 2, wherein each abutment is formed in the head portion.

4. A spanner as claimed in any preceding claims, wherein each moveable member has a rounded edge.

5. A spanner as claimed in any preceding claims, wherein each moveable member is speherical. -10-

6. A spanner as claimed in any preceding claims, wherein each moveable member is held within the opening by a single or separate retainer.

7. A spanner as claimed in claim 6, wherein the or each retainer comprises an elongate strip.

8. A spanner as claimed in claim 6 or claim 7, wherein the or each retainer is located within the opening, and has a separate aperture through which part of each moveable member extends.

9. A spanner as claimed in any of claims 6 to 8, wherein the or each retainer has separate biasing means which biases each moveable member toward an abutment.

10. A spanner as claimed in claim 9 wherein the biasing means comprises a resilient tongue portion.

11. A spanner as claimed in any of the preceding claims wherein, the head portion comprises two opposed jaws, which extend to define a nut receiving region and a throat, the throat being of sufficient size allow passage of the nut or bolt-head therethrough.

12. A spanner as claimed in claim 11, wherein the throat is slightly narrower than the distance between opposed corners of the nut or bolt-head.

13. A spanner as claimed in any of the preceding claims, having four moveable members, each one associated with a trough and defining an abutment.

14. A spanner as claimed in claim I and as substantially herein described with reference to and as illustrated in the accompanying drawings.