Self-adjusting socket

Abstract

 A multi-socket self adjusting spanner comprises an outer socket (30) having an open end adapted to engage a nut or the like and a closed end, and nested within it a number of inner sockets (31-33) each having an open end adapted to engage a nut or the like, and each slidable within the outer socket (30) and spring-loaded towards the open-end of the outer socket. When a nut of a given size is engaged by the spannner all those sockets which are smaller in size than the nut are pushed back within the outer socket (30) and all those which are larger than the nut surround and engage the nut. Each inner socket (31-33) has its open end recessed slightly from the open end of its outer neighbour so that the spanner centers easily on a nut. The inner sockets (31-33) may have, to provide extra strength and the spring rate of the springs (40-42) urging the inner sockets towards their operating position varies so that the outermost inner socket (33) has a stiff spring (42) and the innermost socket (37) the weakest spring (40), the other springs having strengths varying progressively between these. The inner sockets (31-33) are mounted on a central rod (34) which is attached at one end to the outer socket (30) and the rod maybe slidable longitudinally of the outer socket so as to allow spanner to cope with the greater thickness of nut. Each of the springs (40-42) is disposed coaxially around the rod (34) and the movement of the inner sockets (31-33) is limited by shoulders (35-37) formed on the rod.

Description

[0001] This invention relates to a self-adjusting socket and to an adjustable socket spanner which in use entirely or substantially surrounds a nut or the head of a bolt or other threaded fixing member for the purpose of tightening or loosening the same.

[0002] Sockets and ring spanners are generally preferred by engineers because they engage a nut or bolt head at the greatest number of points in operation. Further, currently used ring spanners and sockets are not adjustable so that an engineer needs a lot of them if he is to feel properly equipped.

[0003] To reduce this difficulty it has been proposed in the prior art to provide a socket with a number of tubular inserts which are open at both ends and slidable within the socket between working and non-working positions. The idea is that the socket is placed over a nut and adjusts itself by reason of those tubular inserts which are too small to embrace the nut being pushed out of the way and those which are just large enough to embrace the nut doing so.

[0004] In prior proposals, the inserts are spring urged towards the position of use and are stopped there by having out-turned lips by which they rest upon each other. Further, it has been found that it is desirable to have some manually adjustable retaining means which keeps a selected number of the inserts in the position of use and prevents them sliding away therefrom, against the spring force. However, prior proposals have generally been notable for their complexity and expense in potential manufacture with the result that few, if any, are known to have been commercialised.

[0005] The aim of the present invention is to reduce the above difficulties and provide a self-adjusting socket or spanner which is more readily and cheaply assembled.

[0006] According to the present invention, there is an adjustable socket device comprising: an outer socket, open at one end and closed at the other and shaped to engage a nut or the like; a plurality of inner sockets geometrically similar to and disposed within the outer socket, each inner socket being a sliding close fit within one of the outer socket and the outwardly adjacent inner socket; springs, having successively increasing spring forces, urging respective ones of said inner sockets longitudinally of said outer socket towards the open end; and a rod disposed within the outer socket and passing through said inner sockets and respective limiting means on said rod effective to limit movement of the inner sockets longitudinally of the outer socket beyond their position of use, the inner sockets being closed at their ends remote from the open end of the outer socket.

[0007] Thus, there is a number of inner sockets, slidable within the outer socket and offering alternative sizes of socket to engage correspondingly sized nuts. The rod passes through the sockets and has one or a plurality of radial enlargements, corresponding to the number of inner sockets, beyond which the sockets cannot pass in a direction outwardly of the outer socket. Springs acting on the inner sockets at one end react at the otherend against the interior of other inner sockets or the interior of the outer socket. The spring forces are so designed that each socket is harder to move into the inner socket than the one next smallest in size.

[0008] The rod can be easily provided with the springs and the inner sockets and then located inside the outer socket, for instance by extending through the top thereof and engaging a nut. Further, the rod can be slidable relative to the outer socket which is particularly useful where large nuts are engaged to prevent interference between the end of the rod and the nut.

[0009] Accordingly, with the invention, an adjustable arrangement is provided without the need for complex and costly retaining means and without the need to bend over retaining lips on the slidable inserts or inner sockets.

[0010] The invention also provides a spanner provided with at least one such device. Such a spanner can include a handle extending from the or each socket device to be manually gripped for the purpose of turning the device. The handle can be integrally fixed, normally perpendicular to the axis of the sockets, or it could be separate from the socket device to engage it in use. The device can be one of several interchangeable socket devices provided in a set to engage nuts, each having projections or shaped parts which are to be engaged with a manually or mechanically operable tool, for the purpose of rotation.

[0011] The invention will be more clearly understood from the following description which is given by way of example only, with reference to the accompanying drawings, in which:-

[0012] Figures l, 2 and 3 are longitudinal sectional views of an embodiment of the invention in three alternative dispositions of use.

[0013] Shown in Figures l, 2 and 3 is a device comprising an outer socket 30 which is closed at one end. The interior of the socket is hexagonal so that it can engage a nut of that shape. A recess is provided in the closed end of the socket at 43. This can take a variety of forms but is preferably square in shape so as to be engaged by a square projection from a handle which is used on this and a number of other similar socket devices. Three slidable inserts or inner sockets 3l, 32, 33 are located within the outer socket 30. Extending through the outer socket 30 is a rod 34 which has a stepped formation and which extends through apertures in the slidable inserts 3l, 32, 33. As can readily be appreciated, the smallest insert 3l is limited from movement beyond the end of the rod by a rim 35 and in succession the inserts 32 and 33 are limited in outward movement by steps 36 and 37. The rod itself is supported within the socket by being threadedly engaged with a nut 38, located in a recess 39, which is shown to be of smaller size than the recess 43. Alternatively recess 39 could be a continuation of recess 43 with the same cross section. The recess 39 has such a cross-sectional shape and size that the nut 38 is a close fit within it. The nut 38 is thereby prevented from rotating with the rod 34 when the rod 34 is screwed into or out of it during assembly or disassembly of the socket. The end 35 of the rod may have a transverse slot enabling assembly and positioning with the use of a screwdriver with the nut 38 being held against rotation in the recess 39. Springs 40, 4l and 42 act respectively on the inner end faces of the inserts 3l, 32, 33 and are between those end faces and next inward adjacent faces of other sockets or of the outer socket 30. These springs have successively increasing spring forces so that 40 is the most easily compressed and 42 the most difficult to compress. Shown slightly exaggerated is the way in which slidable inserts 3l, 32, 33 are stepped back from the orifice of the outer socket 30 as this is found to assist engagement. In use, if a nut to be turned fits within insert 3l the socket is used in the configuration shown in Figure l. If the nut is of a size bigger, as shown in Figure 2, the insert 3l is pushed to the right as shown but because the spring forces of springs 4l and 42 are greater than that of spring 40, these do not move or move only a little and inserts 32 and 33 remain in place. Figure 3 shows the position where all three inserts are moved out of the position of use as the nut if of a size to engage the interior of the outer socket 30.

[0014] It will be seen that the springs 40, 4l, 42 surround the rod 34 which therefore has a locating function in respect of these springs.

[0015] The inserts having closed ends are considerably stronger than the sleeve type of insert previously proposed for multi-fitting sockets. Formation is relatively easy as there is no delicate formation of out-turned lips and the mechanism for preventing movement of the inserts outwardly of the outer socket is simple and easy to effect. The socket is readily assembled, the slidable inserts and springs are threaded on the bolt 34 which is then screwed in as described using the nut 38.

[0016] As shown in Figure 3, where thick nuts are employed these can engage the end of the bolt 34 which is free to move axially of the outer socket so that the nut 38 moves along the recess 39.

[0017] The assembly has the advantage over previous constructions that it would be possible readily to supply alternative sets of inserts, for instance for imperial as opposed to metric sizes or vice versa which would have slightly thinner or thicker walls of inserts and allow a single main socket and a corresponding handle to be used for a still further number of sizes of nuts.

[0018] The different spring forces can be obtained by using the same spring material but having reduced spring diameters as between the springs 40, 4l and 42 which increases the force needed to compress them. Alternatively, more than one spring or, longer springs in a semi-compressed state can be located for instance in place of the spring 42 to as to increase the compressive resistance in respect of the outermost of the slidable inserts.

[0019] The exterior of the outer socket 30 has a hexagonal shape of a standard size so that the exterior of the socket 30 may be engaged and rotated by a conventional ring, socket or open-ended spanner. This feature allows the socket to be used without the need for a specially adapted handle which is specific to the socket.

Claims

1. An adjustable socket device comprising: an outer socket (30), open at one end and closed at the outer and shaped to engage a nut or the like; a plurality of inner sockets (3l-33) geometrically similar to and disposed within the outer socket, each inner socket being a sliding close fit within one of the outer socket and the outwardly adjacent inner socket; characterised by springs (40-42) having successively increasing spring forces, urging respective ones of said inner sockets longitudinally of said outer socket towards the open end; and a rod (34) disposed within the outer socket and passing through said inner sockets and respective limiting means (35-39) on said rod effective to limit movement of the inner sockets longitudinally of the outer sockets beyond their position of use, the inner sockets being closed at their ends remote from the open end of the outer socket.

2. An adjustable socket according to claim l characterised in that said springs (40-42) are disposed between the end walls of their respective socket and the ends of the adjacent larger sockets.

3. An adjustable socket according to claim l or 2 characterised in that the springs (40-42) are coil springs disposed coaxially around the said rod.

4. An adjustable socket according to claim l, 2 or 3 characterised in that the limiting means comprise shoulders (35, 36, 37) formed on the rod (34), there being the same number of shoulders as there are inner sockets, each shoulder defining a junction between portions of the rod having a successively greater diameter, and each inner socket being mounted behind a respective shoulder in a sliding close fit on a respective one of said portions, the movement of a respective inner socket being limited by virtue of its end wall coming into abutment with the said respective shoulder.

5. An adjustable socket according to any preceding claim characterised in that the rod (34) extends through the closed end of the outer socket and threadedly engages a nut (38) to be retained thereby.

6. An adjustable socket according to claim 5 characterised in that the nut (38) is received in a sliding close fit within a recess defined in the closed end of the outer socket.

7. An adjustable socket according to any preceding claim characterised in that the rod (34) is slidable longitudinally of the outer socket.

8. An adjustable socket according to any preceding claim characterised in that the exterior of the outer socket (30) is hexagonal in shape.

9. An adjustable socket according to any preceding claim characterised in that the outer socket (30) is adapted to be fitted to a separate handle, or is formed integrally with a handle.

l0. An adjustable socket according to any preceding claim characterised in that the limiting means (35-39) are adapted, and the length of the inner sockets (3l-33) are such, that the open end of each inner socket is recessed from the open end of the outwardly adjacent socket.

Drawing