The present invention relates to tools, particularly to spanners/wrenches.

Spanners, or wrenches, are commonly used in the construction industry, and frequently in DIY to tighten or loosen nuts and/or bolts . A conventional spanner comprises a shaft and a jaw section, the jaw section being of a fixed size to engage with a specific size nut/bolt.

A known improvement to the conventional spanner is an adjustable spanner. An adjustable spanner usually comprises a shaft and an adjustable jaw section such that the gape of the jaw section can be adapted to engage with different sizes of nut.

A problem arising with both conventional and adjustable spanners is that, particularly in situations where there is little room for movement of the shaft, the spanner must be removed from the nut and relocated at a different angle such that the nut can be screwed or unscrewed as desired. Furthermore, a user must manually adjust the gape of the jaw section to fit a nut/bolt. Clearly, this takes time for a user to negotiate the removal and relocation of the spanner about the nut and to adjust the gape of the jaw section.

One known solution to the above problems is the provision of a ratchet spanner. A ratchet spanner comprises a shaft and a circular aperture to accommodate a nut/bolt (a ring spanner) . The circular aperture usually has a mobile insert therein having teeth to engage with the nut/bolt which is secured, via a ratchet mechanism, to the body of the spanner. The mobile insert can rotate independently of the shaft of the spanner and can be locked so as to rotate with respect to the body of the spanner in one direction of rotation, but upon counter-rotation remain fixed with respect to the body of the spanner. In this manner, a nut/bolt may be loosened or tightened without disengaging the spanner from the nut/bolt.

A problem encountered with the ratchet spanner, is that because the nut engaging portion is not open-ended, the spanner must be passed entirely over the nut/bolt, yet in some instances there may be obstructions to doing this. Consequently, this spanner is not suitable for all applications.

It is one aim of embodiments of the present invention to address the above mentioned problems and provide a spanner which may be used without having to disengage from the nut/bolt, and avoid the problems associated with ring spanners .

According to a first aspect of the present invention there is provided a spanner comprising a shaft, a jaw section, a locking device and locking device returning means, the jaw section comprising at least one fixed jaw member and at least one movable jaw member, the locking device being operable to lock the distance between the at least one fixed jaw member and the at least one movable jaw member upon application of pressure by a user, the locking device returning means being operable to return the locking device to an unlocked state when pressure is released by a user, wherein the jaw section is operable, in use, to splay and be passed over a nut to substantially encircle said nut.

Preferably, the jaw section is situated toward a first end of the shaft. More preferably, the jaw section is situated substantially at the first end of the shaft.

Preferably, the shaft comprises at least one shaft member. More preferably, the shaft comprises at least two shaft members. Preferably, the at least two shaft members extend from the first end of the shaft toward a second end of the shaft. Preferably, the at least two shaft members are adjacent to one another and preferably of a substantially equal length. Preferably, the at least two shaft members extend along the entire length of the shaft .

Preferably, the at least two shaft members are secured together at a second end thereof preferably toward a second end of the shaft. More preferably, the at least two shaft members are pivotably secured together at a second end thereof, preferably toward the second end of the shaft. Preferably, the at least two shaft members are pivotably secured together at a second thereof at the second end of the shaft. Preferably, the at least two shaft members comprise a fixed shaft member and preferably a mobile shaft member.

Preferably, the jaw section is integral with the shaft.

Preferably, the fixed shaft member incorporates the fixed jaw member. Preferably, the fixed jaw member is situated toward the first end of the shaft. Preferably, the fixed jaw member is situated substantially at the first end of the shaft. Preferably, the fixed shaft member and the fixed jaw member are integrally formed. Preferably, the fixed jaw member is integral with the fixed shaft member at the first end of the shaft.

Preferably, the mobile shaft member incorporates the movable jaw member. Preferably, the movable jaw member is situated toward the first end of the shaft. Preferably, the movable jaw member is situated substantially at the first end of the shaft. Preferably, the mobile shaft member and the movable jaw member are integrally formed. Preferably, the movable jaw member is integral with the mobile shaft member at the first end of the shaft. Preferably, the movable jaw member is fixed to the mobile shaft member, but movable with respect to the fixed jaw member.

In an alternate embodiment, preferably at least one of the at least one fixed jaw member and the at least one movable jaw member comprises an adjustable portion operable to adjust the locked distance between the at least one fixed jaw member and the at least one movable jaw member. Preferably, the embodiment also includes adjusting means operable to adjust the adjusting portion.

Preferably, the adjustable portion comprises an arm of the at least one jaw member. Preferably, the adjustable portion is slidably mounted in a channel of the at least one jaw portion. Preferably, the adjustable portion is operable to adjust the locked gape of the jaw.

Preferably, the adjusting means comprises a cylinder which, preferably, comprises a helical rib about its longitudinal axis. Preferably, the helical rib is adapted to engage with at least one slot formed in the adjustable portion.

Advantageously, rotation of the cylinder causes lateral movement of the adjustable portion thereby adjusting the gape of the jaw section.

Preferably, the movable jaw member comprises engaging means operable to engage with the locking device. Preferably, the engaging means are situated toward a rear side of the movable jaw member with respect to the jaw section. Alternatively and preferably, the mobile shaft member comprises engaging means operable to engage with the locking device. Preferably, the engaging means comprises a recess section.

Preferably, the at least two shaft members are held substantially parallel to one another by a resilient bias, which may be elastic returning means. By elastic returning means it is meant any means which can elastically deform to allow the at least two shaft members to diverge upon the application of pressure, but return the at least two shaft members to their substantially parallel state when the said pressure is released. Thus, the two jaw members are preferably returned to a closed position. Examples of suitable elastic returning means include, but are not restricted to, springs, such as leaf springs and coil springs, elastic bands, plastics which exhibit elastic deformation etc. Preferably, the elastic returning means is a spring, more preferably a coil spring. Preferably, the elastic returning means is situated at a point along the shaft between a mid point of the shaft and the first end of the shaft. Preferably, the elastic returning means is situated toward the first end of the shaft. In an alternate embodiment, the elastic returning means may be situated at a point on the shaft immediately rearwardly of the jaw section.

Preferably, the locking device comprises a locking bar which is preferably situated substantially parallel to the shaft. Preferably, the locking bar extends substantially along the length of the shaft. Preferably, the locking bar is C-shaped in cross section. Preferably, the C- shaped cross section of the locking bar accommodates a portion of the shaft therewithin.

Preferably, the locking bar is adapted to be movable with respect to the shaft. More preferably, the locking bar is adapted to be movable away from, whilst maintaining a substantially parallel alignment with respect to the shaft.

Preferably, the locking device further comprises a locking member. Preferably, the locking member is secured to the locking bar, more preferably, pivotably secured. Preferably, the locking member is secured toward a first end of the locking bar proximal to the first end of the shaft. More preferably, pivotably secured to the first end of the locking bar.

Preferably, the locking member comprises at least one engaging member adapted to engage with the mobile jaw member. Alternatively and preferably, the engaging member is adapted to engage with the mobile shaft member.

Preferably, the lock returning means is operable to force the locking bar away from the shaft, thereby releasing the locking device.

Preferably, the lock returning means comprises at least one spring, more preferably, at least one coil spring. Preferably, the lock returning means is connected to the locking bar and the shaft. Alternatively, the lock returning means may be attached to the locking member and the shaft .

Preferably, the jaw portion is adapted to accommodate a hexagonal nut.

Preferably, the jaw members extend more than half way around the perimeter of a nut/bolt to be gripped.

Preferably, the jaw section can accommodate a nut/bolt of a greater diameter than the opening of the jaw section.

Preferably, the jaw members make an enclosure for a nut/bolt. Preferably, arms of the enclosure enclose more than half of the perimeter of a nut/bolt. Preferably, the enclosure encircles greater than half of the perimeter of a nut/bolt.

From substantially the centre of the enclosure, the jaw members preferably encircle an angle greater than approximately 180°, more preferably, greater than 200' most preferably, between 250° and 300°. According to a second aspect of the present invention there is provided a method of rotating a nut/bolt comprising the step of;

locating a nut/bolt within a jaw section of a spanner in accordance with the first aspect, engaging a locking device of the spanner as defined in the first aspect, and applying a pressure to a shaft of the spanner as defined in the first aspect to rotate the spanner.

In an alternate embodiment, according to a further aspect of the present invention, there is provided a spanner comprising a shaft, a jaw section, a locking device and locking device returning means, the jaw section comprising at least one fixed jaw member and at least one movable jaw member, the locking device being operable to lock the distance between the at least one fixed jaw member and the at least one movable jaw member upon application of pressure by a user, wherein the locking device returning means are operable to return the locking device to an unlocked state when pressure is released by a user.

All of the features described herein may be combined with any of the above aspects, in any combination.

Non limiting examples of embodiments of the present invention will now be described with reference to the accompanying drawings in which:

Figure 1 shows a plan view of a first embodiment of a spanner according to the present invention; Figure 2 shows a plan view of a second embodiment of a spanner;

Figure 3 shows a perspective view from above a second embodiment of a spanner; and

Figure 4 shows a perspective view from below a second embodiment of a spanner.

A first embodiment of a fixed width spanner 102 in accordance with the present invention is shown in Figure 1 having a shaft 104 and a jaw section 106. The spanner 102 is designed for use with a given bolt or nut size. The shaft 104 is split along its longitudinal axis into two shaft members: a fixed shaft member 108 and a mobile shaft member 110. The two shaft members 108, 110, are secured together by a pivot 112 toward an end of the shaft 104 distal to the jaw section 106. The two shaft members 108, 110, are held side by side by a spring 114 mounted part way along the shaft 104 toward the jaw section 106.

The jaw section 106 comprises a fixed jaw member 116 which is integrally formed at one end of the fixed shaft member 108 and a mobile jaw member 118 which is integrally formed at one end of the mobile shaft member 110.

The mobile jaw member 118 has a recess section 126 on a rear face thereof operable to engage with a lug 124, as will be described below.

The spanner 102 further comprises a locking bar 120 which extends substantially the entire length of and is parallel with the shaft 104. The locking bar 120 is attached to the shaft 104 at an end distal to the jaw section 106 by a connecting bar 136 via two connected pivots 138, 140. The first pivot 138 connects the locking bar 120 to the connecting bar 136. The second pivot 140 connects the connecting bar 136 to the fixed shaft member 108. At an end of the locking bar 120 proximal to the jaw section 106 there is a locking portion 122 which is pivotally attached to the fixed jaw member 116 via pivot a 132 and the locking bar 120 via pivot 134. The locking portion 122 has the lug 124 which extends from an end of the locking portion 122 distal to the locking bar 120.

The locking bar is held parallel to and in the plane of the shaft 104 because the locking bar 120 is secured at both ends via pivots to connecting members (connecting bar 136 and locking portion 122), which are in turn both pivotally connected to the fixed shaft member 108. The locking bar 120 is held laterally away from the shaft 104 by springs 128, 130 such that when no pressure is applied to the locking bar 120, it is spaced laterally from the shaft 104.

In the present embodiment of spanner 102, there is also provided a ring spanner 128 integrally formed with the fixed shaft member 108 at an end of the shaft 104 distal to the jaw section 106. The ring spanner 128 could alternatively be a ratchet spanner or conventional spanner as described in the preamble.

As a consequence of the spanner 102 having a fixed jaw member 116 and a mobile jaw member 118, an enclosure formed by the jaw section can encircle more than half of the perimeter of a nut/bolt. As shown in figure 1, from a point substantially in the centre of the enclosure, the enclosure encircles about 270°.

The interior surface of the jaw section has a series of angular protrusions 142 which in use engage with the corners of a nut to allow the jaw section to grip the nut, in the usual way.

When the spanner 102 is gripped by a user the locking bar 120 is pushed from its biased outward position towards the shaft 104, thus causing the locking portion 122 to turn about pivot 132, forcing the lug 124 into the recess section 126 and locking the gape of the jaw section 106 to its active, locked gape.

In use, the jaw section 106 of the spanner 102 is offered to a nut with the locking bar 120 not depressed (in the lower dashed position of figure 1) and with the locking bar 120 on the side of the spanner 102 that will be pushed to rotate the nut. The jaws 116, 118 are not locked and can therefore be slipped over a nut/bolt to substantially encircle the nut/bolt by briefly parting and by pivoting about the pivot 112, to then close again once passed the nut. A user then pushes the spanner 102 in the desired direction of rotation thereby depressing the locking bar 120 and engaging the locking portion 122 (i.e. the lug 124 in the recess section 126) . In this manner, the jaw section 106 is locked in position around the nut and the user can then rotate the nut by rotation of the spanner 102. Note that the more force applied by a user to rotate the spanner 102, the more firmly the locking bar 120 is pressed, thus the more firmly the locking portion 122 is held in place. When a user transfers force to the other side of the shaft, i.e. opposite to the desired direction of rotation of the nut/bolt, the locking bar 120 is released and thus the locking portion 122 returns to the unlocked state because of the spring return force supplied by springs 128,130. In this manner, the grip on the nut within the jaw section is released. Therefore, a user can counter-rotate the spanner 102 without rotating the nut because the angular protrusions 142 within the released jaw section 106 will pass over the corners of the nut without engaging therewith. In this manner, the invention provides an open ended ratchet spanner.

A second embodiment of spanner 202 is shown in figures 2, 3 and 4. The second embodiment has a shaft 204 and a jaw section 206. The spanner is designed for use with a given bolt or nut size. The shaft 204 is split along its longitudinal axis into two shaft members: a fixed shaft member 208 and a mobile shaft member 210. The two shaft members 208, 210, are secured together by a pivot 212 at an end of the shaft 204 distal to the jaw section 206. The two shaft members 208, 210 are held side by side by a spring 214 mounted toward the jaw section 206 of the shaft 204.

The jaw section 206 comprises a fixed jaw member 216 which is integrally formed at one end of the fixed shaft member 208 and a mobile jaw member 218 which is integrally formed at one end of the mobile shaft member 210.

The mobile jaw member 218 has a recess section 226 on a rear face thereof operable to engage with a lug 224, as will be described below. The spanner 202 further comprises a locking bar 220 which extends substantially the entire length of and is parallel with the shaft 204. The locking bar 220 is substantially C-shaped in cross section as is shown in figures 3 and 4 and accommodates a portion of the shaft 204 along its length. The locking bar 220 is attached to the shaft 204 at an end distal to the jaw section 206 by two connecting bars 236 (only one shown) , one at a corresponding position on opposing faces of the shaft 204. The two connecting bars 236 are fixed to the locking bar 220 by pivots 238. The pivot 212 extends through the shaft 204 and secures both connecting bars thereto. At an end of the locking bar 220 proximal to the jaw section 206 there are two locking portions 222 (on opposing faces of the shaft 204) pivotally attached to the fixed jaw member 216 via a pivot 232. The pivot 232 extends through the fixed jaw member and secures both locking portions 222 thereto. In addition, the locking bar 220 attaches to the locking portions 222 via pivots 234 (one on each face of the shaft 204) . The locking portions 222 have the lugs 224 referred to above which extend from an end of the locking portions 222 distal to the locking bar 220.

The locking bar is held parallel to and in the plane of the shaft 204, because the locking bar 220 is secured at both ends via pivots 234, 238 to connecting members (connecting bars 236 and locking portion 222) , which are in turn pivotally connected to the fixed shaft member 208. The locking bar 220 is held laterally away from the shaft 204 by a compression spring 228, such that when no pressure is applied to the locking bar 220, it is spaced laterally from the shaft 204. As a consequence of the spanner 202 having a fixed jaw member 216 and a mobile jaw member 218, an enclosure formed by the jaw section can encircle more than half of the perimeter of a nut/bolt. As shown in figures 2, 3 and 4 from a point substantially in the centre of the enclosure, the enclosure encircles about 270° .

The interior surface of the jaw section 206 has a series of angular protrusions 242 which, in use, engage with the corners of a nut to allow the jaw section to grip the nut, in the usual way.

When the spanner 202 is gripped by a user the locking bar 220 is pushed from its biased outward position towards the shaft 204, thus causing the locking portions 222 to turn about pivot 232, forcing the lugs 224 into the recess sections 226 and locking the gape of the jaw section 206 to its active, locked gape.

In use, the jaw section 206 of the spanner 202 is offered to a nut with the locking bar 220 not depressed, thus the jaw section 206 is not locked and the jaw members can therefore splay and be passed over the nut to substantially encircle it by briefly parting and by pivoting about the pivot 212 . A user then pushes the spanner 202 in the desired direction of rotation thereby pushing the locking bar 220 against the shaft 204 and engaging the locking portions 222 (i.e. the lugs 224 in the recess sections 226) . In this manner, the jaw section 206 is locked in position around the nut and the user can then rotate the nut by rotation of the spanner 202. When the grip on the spanner 202 is transferred to the other side of the shaft, i.e. opposite to the desired direction of rotation, the locking bar 220 is released and thus the locking portion 222 returns to the unlocked state because of the spring return force supplied by the spring 228. In this manner, the grip on the nut within the jaw section 206 is released. Therefore, a user can counter-rotate the spanner 202 without rotating the nut, because the angular protrusions 242 within the released jaw section 206 will pass over the corners of the nut without engaging therewith. In this manner, the invention provides an open ended ratchet spanner.

In a further embodiment, as an adaptation of the first and second embodiment (not shown) , the jaw section is adjustable. This embodiment of the spanner is suitable for use with a number of different size nuts/bolts.

The mechanism by which the spanner is rendered adjustable is well known in the art as it is the same mechanism that is used to render conventional spanners adjustable.

The jaw section is adjustable by virtue of an adjustable portion located on the mobile jaw member. It should be appreciated that the adjustable portion may alternatively be located on the fixed jaw member.

The adjustable portion has an arm which is located opposite the fixed jaw member and a lower cylindrical portion. The lower portion has a number of slots along its length.

The lower section of the adjustable portion is accommodated in a hollow channel formed in the mobile jaw member substantially parallel to the plane of movement of the adjustable portion. The hollow channel comprises an aperture into which adjusting means, in the form of a cylinder having a helical rib along its longitudinal axis, is accommodated. The helical rib of the cylinder is accommodated within the slots of the lower portion of the adjustable portion. By rotating the cylinder, the adjustable portion is moved with respect to the mobile jaw member. In use, the adjustable portion may be adjusted such that the gape of the jaw section, when in the locked configuration, can accommodate different sizes of nuts/bolts. In this manner, the present invention can provide an adjustable, open ended ratchet spanner.

As will be appreciated from the above description and by reference to the accompanying drawings the main differences between the first and second exemplary embodiments are: the position of the resilient bias that holds the two shaft members parallel to one another; the C-shaped cross section of the locking bar 220 in the second embodiment; the number and position of springs on the locking bars 120, 220; and the provision of a ring spanner on the first embodiment.

A spanner made in accordance with the present invention may be used without having to disengage from a nut/bolt and avoids the problems associated with conventional spanners and ring spanners . The spanner can simply be pushed onto a nut causing the jaw section to open without further action from a user. In use, when rotating a nut/bolt, upon counter rotation of the spanner, the jaw portion does not engage with the nut thus allowing the spanner to act as an open ended ratchet spanner. Thus the spanner is very easy to use. Engagement of the spanner on a nut/bolt and rotation of a nut/bolt is particularly easy.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , or to any novel one, or any novel combination, of the steps of any method or process so disclosed.