ADJUSTABLE SPANNERS

Abstract: The invention provides an adjustable spanner having one fixed jaw (11) and one movable jaw (12), the fixed jaw being mounted on or formed integrally with the body or handle (10) of the spanner, and the movable jaw being arranged to slide in the body or handle of the spanner relative to the fixed jaw; in which the movable jaw (12) is provided with a first set of serrations (15) and a locking member (17) provided with a second set of serrations (16) is movably mounted in the body of the spanner to move between a locking position in which said second set of serrations engage wih said first set of serrations to lock the movable jaw (12) in an operative position, and a release position in which the second set of serrations are clear of said first set of serrations to allow adjusting movement of the movable jaw; wherein releasable locking means (21) is provided for locking the locking member (17) positively in said locking position.

Description: ADJUSTABLE SPANNERS This invention relates to an adjustable spanner. Adjustable spanners were well known to have one jaw of the spanner fixed to a handle, and a second jaw of the spanner adjustable relative to the first by means of a screw threaded device embodied in the handle. The adjustment of such spanners is a time consuming operation, and the inevitable amount of slack or backlash between the screw mechanism and the movable spanner jaw, means that they rarely make a positive engagement on the faces of a hexagonal nut in the fashion of a fixed spanner. It is an object of the present invention to provide an adjustable spanner which alleviates these disadvantages. Accordingly, the present invention provides an adjustable spanner having one fixed jaw and one movable jaw, the fixed jaw being mounted on or formed integrally with the body or handle of the spanner, and the movable jaw being arranged to slide in the body or handle of the spanner relative to the fixed jaw; in which the movable jaw is provided with a first set of serrations, and a locking member provided with a second set of serrations is movably mounted in the body or handle of the spanner to move between a locking position in which the second serrations engage the first serrations to lock the movable jaw in an operative position, and a release position in which the second serrations are clear of the first serrations to allow adjusting movement of the movable jaw. Releasable locking means is provided for locking the locking member positively in said locking position. Preferably the locking member is slidably mounted in said body or handle to move in a direction transverse to the direction of movement of the movable jaw. Preferably the locking means comprises a pin movably mounted in the body or handle for movement between a locking and a release position, said pin having a cam surface adapted to engage said locking member and urge it towards the movable jaw on movement of the pin between its locking and release positions. Preferably the pin of the locking means is slidably mounted in said body or handle. The pin may be of circular cross-section, in which case the cam surface is a tapered portion on the surface of the pin. The pin may be of rectangular cross-section, in which case the cam surface is an inclined portion on one side thereof. In another arrangement, the pin is rotorably mounted in the body or handle, in which case the cam surface is a surface cut into the periphery of the pin. Preferably the locking member is resiliently biased away from the movable jaw by means of a spring. Preferably the first and second sets of serrations have a pitch distance corresponding to the increments in the size of the nuts to be turned by the spanner. Preferably a scale arrangement is provided between the fixed and movable jaws so that the setting of the spanner may be indicated. In order to promote a fuller understanding of the above and other aspects of the present invention, an embodiment will now be described, by way of example only, with reference to the accompanying drawings, in which; Figure 1 snows a- side view in part cross-section of a spanner embodying the invention, Figure 2 shows an external view of the spanner of Figure 1 , Figure 3 shows a top view of the spanner of Figure 1, Figure 4 shows a view similar to Figure 1 of a further spanner embodying the invention, Figure 5 shows a top view of the spanner of Figure 4, Figure 6 shows a part cross-section on the line VI-VI of Figure 4, Figure 7 shows a view similar to Figure 1 of a further spanner embodying the invention, Figure 8 shows a top view of the spanner of Figure 7, Figure 9 shows a detail of the locking means of Figure 7, Figure 10 shows a cross-section on the line XX-XX. - - Figure-11 -shows-a-view-similar to Figure 1 of a further spanner embodying the invention, Figure 12 shows a top view of the spanner of Figure 11, Figure 13 shows a detail of the locking member of the spanner of Figure 1 , and Figure 14 shows a cross-section on the line XIV-XIV of Figure 13. The spanner shown in Figures 1, 2 and 3 of the accompanying drawings, comprises a handle 10 having a fixed spanner jaw 11 formed integrally therewith, and a movable spanner jaw 12 which is freely slidable in the body of the spanner which is formed integrally with the handle 10. The movable jaw 12 has a "keyhole" shaped projection 13 which moves in a correspondingly shaped slot 14 formed in the body of the spanner adjacent to fixed jaw 11, in conventional manner per se. A rear surface of the movable jaw 12 is provided with a first set of serrations 15 which can be engaged by a corresponding second set of serrations 16 which are formed on a locking member 17. The locking member 17 is slidably mounted in a suitable aperture 18, which is formed in the body of the spanner, so as to be movable in a direction transverse to the direction of movement of the movable jaw 12, between a locking position with the first set of serrations in engagement with the second set, and a release position with the first set of serrations clear of the second set. It can be seen that with the locking member in such locking position, the movable jaw 12 is securely locked in a position to fit a chosen nut size, while with the locking member in such release position, the movable jaw 12 may be freely adjusted to a chosen nut size. The serrations 15 and 16 which are naturally of matching pitch, are preferably chosen in pitch to correspond either to inch size or metric size increments of nut sizes upon which the spanner is to be used. The movable jaw 12 may also be provided with an engraved pointer 19 which moves against a scale 20 provided on the fixed jaw or body of the spanner (see Figure 2), so that the movable jaw may be set to a given nut size for use. Locking means indicated generally at 21 is provided in the body of the spanner to releasably engage and retain the locking member 17 in the locking position with its serrations 16 in engagement with the serrations 15 of the movable jaw 12 of the spanner. In this embodiment the locking means 21 comprises a pin 22 which is slidably mounted in the body of the spanner 10 for movement, in a direction transverse to that of the locking member 17, and generally parallel with that of the movable jaw 12. The pin 22 is provided with a cam surface in the form of a tapered portion 23 which is arranged to engage a projection 24 formed on the back of the locking member 17. Thus it can be seen that downward movement, as seen in the drawings, of the pin 22, between a release position and a locking position, will cause the locking member 17 to move into its locking position in engagement with the movable jaw 12 and lock it in that locking position. The taper 23 can be made "self-locking" so that moderate force on the top of the pin 22 will achieve a firm locking of the movable jaw 12, which may be enhanced by a light tap in the top pin 22. A shoulder 25 is provided around the top of the pin 22 arranged to engage a shoulder 26 formed in the body of the spanner to prevent the pin 22 moving into the body of the spanner beyond the distance necessary for secure locking. A necked portion 27 is formed on the pin 22 immediately below the tapered portion 23 to provide a recess so that when the tapered pin is moved upwards, as seen in the drawings, the locking member 17 is released and the projection 24 may be received in the recess, allowing free movement of the movable jaw 12 with the serrations out of engagement. The locking member 17 may be assembled in the body of the spanner through a suitable aperture in a side face which is subsequently covered by a cover plate 28, as shown in Figure 2. A stop screw 29 may be provided in the body of the spanner to engage in a corresponding slot 30 in the movable jaw 12, to prevent the movable jaw from falling completely out of the spanner when the locking member 17 is released. The engagement of the stop screw 29 in the slot 30, which occurs at wide or large settings of the spanner, also helps to transmit torque forces from the handle to the movable jaw, thus promoting the rigidity of the spanner in use at large settings. Thus it can be seen that the embodiment provides an adjustable spanner which can be firmly locked in a chosen adjusted position to accommodate a given nut size, by the simple expedient of moving the pin 22 into a locking position, with a suitable tap from a hammer if necessary. Further, on release of the pin 22, with a suitable tap from a hammer if necessary on the bottom end, the adjustable jaw is released and can be easily adjusted to a chosen size. Once the movable jaw is locked by means of the pin 22 and locking member 17, the adjustable spanner behaves as if it was a solid spanner and thus alleviates the disadvantages of previous adjustable spanners as discussed above. Figures 4, 5 and 6 show a further spanner embodying the invention which is generally similar to that of Figures 1, 2 and 3; and where parts have a generally common design or purpose to those of Figures 1, 2 and 3, they have been given the same reference numbers. In this arrangement, the pin 22 is of rectangular cross-section and slides in a corresponding cross-section slot in the body of the spanner. The tapered portion 23 of the previous embodiment is replaced by an inclined cam surface 40, while the recessed or necked part 27 of the previous embodiment is replaced by a recess 41. In this embodiment a compression coil spring 42 is provided to be active between a shoulder formed in the body of the spanner and a pin 43 provided in the locking member 17 adjacent the projection 24, thus to bias the locking member 17 into its release position. In other respects the embodiment of Figures 4, 5 and 6 operates in an exactly similar fashion to that of Figures 1, 2 and 3. Figures 7, 8, 9 and 10 show a further spanner embodying the invention which is generally similar to that of Figures 1, 2 and 3; and where parts have a generally similar design or purpose to those of Figures 1 , 2 and 3, they have been given the same reference numbers. In this embodiment the axially moving pin 22 is replaced by a rotatable pin 50. The rotatable pin 50 is axially located in the body of the spanner by means which are known per se and not shown in the drawings, and is rotatable through a small angle X by means of a handle 51. The tapered surface 23 of Figures 1, 2 and 3 is replaced by a cam surface 52 formed in a notch in the peripheral surface of the pin 50, which engages the projection 24 to urge the locking member 17 into engagement with the movable jaw 12. The cam surface 52 terminates in a recess 53 which corresponds to the recess 27 in the embodiment of Figures 1 , 2 and 3. The locking member 17 is biassed out of engagement with the movable jaw 12, by means of a spring 54 in a similar manner to that of the embodiment of Figures 4, 5 and 6. In other respects, the embodiment of Figures 7, 8, 9 and 10 operates in an exactly similar fashion to that of Figures 1, 2 and 3. Figures 11, 12, 13 and 14 show a yet further spanner embodying the invention; and where parts have a generally similar design or purpose to those of Figures 1, 2 and 3, they have been given the same reference numbers. In this embodiment, the slidable locking member 17 of the embodiments of Figures 1, 2 and 3 is replaced by a rotatable locking member 60 which is axially located for rotation in the body of the spanner. The locking member 60 is of generally circular cross-section and is axially retained in a bore in the body of the handle by means of a screw 61. The locking member 60 is rotatable through a small angle X in the body of the spanner by means of a small handle 62. The locking member 60 is formed around part of its periphery, with a second set of serrations 63 which correspond in purpose to the serrations 16 on the locking member 17 of Figure 1. Adjacent the serrations 63 around the periphery of the locking member 60, is a recessed or cut-away portion 64. The first set of serrations 15 on the movable jaw 12 are made accurate in form to wrap round the second set of serrations 16 on the locking member 60, which last are also accurate in form being formed on the cylindrical surface of the locking member. In use, the locking member 60 may be rotated by the handle 62 to a locking position in which the first set of serrations 63 engage the second set of serrations 15 on the movable jaw 12, to lock the movable jaw in position, and a release position in which the cut-away portion 64 allows clearance for the second set of serrations 15 on the movable jaw 12, thus allowing the movable jaw to be adjusted to a fresh position. When the jaw has been adjusted, the locking member 60 is moved back to bring the first set of serrations 63 into engagement again. In other respects the embodiments of Figures 11 , 12, 13 and 14 operates in an exactly similar fashion to that of Figures 1, 2 and 3. Thus it can be seen that the present invention in its various embodiments, provides an adjustable spanner which can be firmly locked in position to accommodate a given nut size, while providing for the simple and convenient adjustment of the spanner to suit various nut sizes.

Claims: CLAIMS 1. An adjustable spanner having one fixed jaw (11) and one movable jaw (12), the fixed jaw being mounted on or formed integrally with the body or handle (10) of the spanner, and the movable jaw being arranged to slide in the body.or handle of the spanner relative to the fixed jaw; in which the movable jaw (12) is provided with a first set of serrations {15.) and a locking member (17) provided with a second set of serrations (16) is movably mounted in the body of the spanner to move between a locking position in which said second set of serrations engage with said first set of serrations to lock the movable jaw (12) in an operative position, and a release position in which the second set of serrations are clear of said first set of serrations to allow adjusting movement of the movable jaw; wherein releasable locking means (21) is provided for locking the locking member (17) positively in said locking position. 2. An adjustable spanner as claimed in Claim 1, wherein said locking member is slidably mounted in said body or handle to move in a direction transverse to the direction of movement of the movable jaw (12). 3. An adjustable spanner as claimed in Claim 1 or 2, wherein said locking means (21) comprises a pin (22,50) movably mounted in said body or handle for movement between a locking and a release position, said pin having a cam surface (23,40,52) adapted to engage said locking member (17) and urge it towards the movable jaw (12) on movement of the pin between its locking and release positions. 4. An adjustable spanner as claimed in Claim 3, wherein said locking member (17) is provided with a projection (24) arranged to engage said cam surface (23,40,52). 5. An adjustable spanner as claimed in Claim 4, wherein said pin is provided with a recess (27,41,53) arranged to receive said projection (24) when said locking member (17) and said pin (22,40,50) are in their release positions. 6. An adjustable spanner as claimed in Claim 3, 4 or 5, wherein said pin (22,40) is slidably mounted in said body or handle. 7. An adjustable spanner as claimed in Claim 6, wherein said pin (22) is of circular cross-section and said cam surface is a tapered portion (23) of the surface of the pin. 8. An adjustable spanner as claimed in Claim 6, wherein said pin (40) is of rectangular cross-section and said cam surface is an inclined portion (40) on one side thereof. 9. An adjustable spanner as claimed in Claim 6, 7 or 8, wherein said pin (22,40) is provided with a stop (25) to prevent over-tightening of the locking means (21). 10. An adjustable spanner as claimed in Claim 3, 4 or 5, wherein said pin (50) is rotorably mounted in said body or handle. 11. An adjustable spanner as claimed in Claim 10 wherein said cam surface is a surface 52 cut into the periphery of said pin (50). 12. An adjustable spanner as claimed in any preceding claim, wherein said locking member (17) is resiliently biased away from said movable jaw by means of a spring (42). 13. An adjustable spanner as claimed in any preceding claim, wherein said first (15) and second (16) sets of serrations have a pitch distance corresponding to the increments in size of the nuts to be turned by the spanner. 14. An adjustable spanner as claimed in any preceding claim, wherein a scale (20) is provided on said fixed or movable jaw and a pointer (19) is provided on said movable or fixed jaw respectively, whereby the spanner setting may be indicated.

Inventors: HARRISON IAN AUSTIN, HARRISON, IAN, AUSTIN
Applicants: HARRISON IAN AUSTIN, HARRISON, IAN, AUSTIN
Application year: 1992
Main classification: B25B13
IPC codes: B25B13