GB2178134A - Flexible socket construction - Google Patents

Abstract

In an improved flexible socket drive assembly a yieldable biasing means 78 is operative to urge the socket member 18 into coaxial relationship with the input axis of rotation so as to maintain control thereof and prevent potential whipping of the socket member. The socket member itself is specifically adapted to enable quick, easy and relatively inexpensive replacement thereof without requiring the entire apparatus to be discarded. <IMAGE>

Description

SPECIFICATION Flexible socket construction Background and Summary of the Invention The present invention relates generally to an improved socket wrench assembly and more particularly to such a socket assembly which is able to rotatably drive a fastener about an axis lying parallel to but offset from the rotational axis of the torque applying apparatus.

There exist many applications wherein it is not possible to achieve a true axial alignment between the rotational axis of driven and driving members such as for example a bolt or nut to be secured and the torque applying means. Universal joints have been developed which are designed to accommodate an angular offset between the respective members and may be doubled up whereby the respective axis of the driving and driven members may be positioned at other angles with respect to each other. However, conventional universal joints typically comprise two pivot axis offset from each other by 90 interconnecting input and output portions thereof without any means to yieldably or otherwise urge the respective input and output portions into axial alignment with each other.Accordingly, even when only a single universal joint is employed in a manual fastener torquing application, it becomes difficult to maintain adequate control between the driving and driven portions. This difficulty is multiplied when two or more universal joints are interconnected in series. When the driven sockets form a part of automated equipment, it becomes critical to provide arrangements wherein the driven member is maintained under substantially continuous control in order to assure accomplishment of the intended task. Further, while it is important that control of the driven socket be maintained, it is also important that the socket be free to move somewhat so as to easily be axially aligned with the nut/bolt or the like which is to be driven.

An additional consideration which is particularly important with sockets utilized in assembly line operations is replacement costs.

Such sockets are subjected to severe wear under these conditions to the extent that replacement costs become a significant factor.

Accordingly, proper alignment of the socket with the bolt/nut to be driven thereby is important in reducing the wear on the socket and hence extending the useable life thereof.

Further, as the socket tends to be subject to the greatest degree of wear, it is desirable to minimize the costs of replacing same.

The present invention overcomes these problems by providing a socket assembly which includes a socket member movably retained within a housing which in turn is connected to one end of a member forming part of a ball and socket connection, with the other member thereof being connectable to the driving member. A first spring member operates within a surrounding slidable sleeve member to urge the two members forming the ball and socket joint into coaxial position and a second spring acts against the socket member to urge it into a forward position with respect to the housing wherein it is in axial alignment with the two members of the ball and socket joint. The socket member includes projections which are received within slots provided on the housing so as to effect transmission of the rotational forces there through to the fastener being driven.The housing is preferably removably connected to the one member of the ball and socket joint whereby replacement of the socket member may be very easily accomplished. Because both the socket and housing connection and ball and socket connection each allow for simultaneous movement about two perpendicular axis, the resulting socket assembly is able to position both the socket member and driving member in parallel axial radially offset relationship or even a position wherein the driven fastener faces in a direction away from the axis of rotation of the driven member when necessary so as to avoid excessive wear resulting from a non-coaxial engagement between the driven fastener and socket as well as to avoid the need to radially shift the driving means.This is particularly important when automated equipment is employed in securing of the fasteners as it become exceedingly difficult and costly to design such equipment to shift radially to accommodate slight position variations between successive operations. Further, because the respective springs operate to urge the components into overall axial alignment with respect to each other, it is possible to maintain a greater control throughout the operational cycle.

Additional advantages and features of the present invention wili become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.

Brief Description of the Drawings Figure 1 is an exploded view of the improved socket assembly of the present invention; Figure 2 is a section view of the improved socket assembly, the section being taken along a radial plane passing through the axis of rotation; Figure 3 is an end view of the socket member forming a part of the socket assembly of the present invention; Figure 4 is a section view similar to that of Fig. 2 but showing the socket member and drive connecting portion with their rotational axis in parallel offset relationship; and Figure 5 is a fragmentary view of another embodiment of the present invention with por tion thereof broken away.

Description of the Preferred Embodiment Referring now to the drawings and specifically to Figs. 1 and 2, there is illustrated a flexible socket assembly in accordance with the present invention illustrated generally at 10. Flexible socket assembly 10 comprises a drive connector member 12, an intermediate member 14, housing member 16 and socket member 18, all of which are interconnected to form a generally cylindrically shaped elongated assembly.

Drive connector member 12 has a generally cylindrically shaped center shank portion 20 from which a generally spherically shaped ball portion 22 extends in one direction and an enlarged diameter flange portion 24 extends axially from the opposite end. A suitable recess 26 is provided extending axially inwardly into connector member 12 from one end thereof which is designed to accommodate a suitable driving member such as a conventional square projection commonly employed with socket drives. A cross bore 28 extends diametrically through the spherical portion which bore 28 has an increasing diameter as it extends radially outwardly in opposite directions from the center of the spherical portion 22.

Intermediate connector 14 is also generally cylindrical in shape and includes a smaller diameter portion 30 at one end thereof through which a first bore 32 extends axially and a larger diameter portion 34 at the opposite end through which a larger diameter bore 36 extends. Bore 32 is suitably sized so as to mo vably accommodate spherical portion 22 of the drive connector member 12 which is retained therein by means of a pin 38 extending through diametric openings 40 in the sidewalls of the smaller diameter portion 30 and the cross bore 28 in spherical member 22 so as to thereby form a ball and socket connection therebetween.

In order to urge the ball and socket connected drive connector member 12 and intermediate connector member 14 into axial alignment, a helical coil spring 42 is provided positioned in surrounding relationship to an ax ially center shank portion 20 of the drive connector member 12 and bearing at one end thereof against an axially facing shoulder 44 provided between shank 20 and flange portion 24. The other end of spring 42 is received within a bore 46 provided in a sleeve member 48 and bears against an axially facing shoulder 50 defined by a reduced diameter continuation portion 52 of said bore 46. The forward end surface 54 of sleeve member 48 is thus biased against a rearwardly facing surface 56 of intermediate connector member 14 and serves to maintain it in axial alignment with the drive connector member 12.It should be noted that the length of bore 46 within sleeve member 48 is sufficient so as to enable it to extend beyond the shoulder 44 on drive connector member 12 so as to protect spring member 42 from external damage as well as to accommodate relative axial movement therebetween.

Housing member 16 is also generally cylindrical in shape having a hollow interior defined by a first bore portion 58, the outer end of which is threaded and a forwardly extending continuation thereof 60 of a reduced diameter.

A plurality of four generally Z-shaped slots 62 are provided generally equally spaced around the periphery thereof. Each of the slots 62 include a first generally axially elongated portion 64 the rearward end of which opens into the enlarged diameter portion 58, a generally circumferentially extending portion 66 and a second axially extending portion 68 circumferentially offset from portion 64 and interconnected therewith by means of portion 66.

Socket member 18 has a generally rounded outer peripheral surface 69 of a diameter just slightly less than the diameter of reduced diameter portion of bore 60 in housing 16. A plurality of four integrally formed generally equally circumferentially spaced cylindrically shaped projections 70 extend generally radially outwardly from the spherical surface 69 of socket member 16 adjacent the forward end thereof. Projections 70 are suitably sized so as to be received within respective slots 62 in housing 16 and to cooperate therewith to prevent relative rotation therebetween. A suitably sized conventional six or twelve point hex shaped bolt/nut receiving bore 72 is also provided extending axially inwardly from the forward end of socket member 16. An annular groove 74 is provided within bore 72 intermediate its ends within which is seated a resilient member 76 such as for example an 0ring.Member 76 is designed to provide a slight frictional engagement with a nut or bolt inserted into bore 72 so as to retain same during the initial portion of a driving operation.

In order to urge socket member 18 forwardly within housing 16 and into axial alignment with aligned drive connector member 12 and intermediate connector member 14, a second coil spring 78 is provided extending between an axially outwardly facing shoulder 80 provided within intermediate connector member 14 and a ring shaped spring seat member 82 which in turn bears against the axially rearward surface 84 of socket member 18. In this manner, socket member 18 which is free to move within housing 16 will be urged axially forwardly with respect thereto, engagement between the axially forward end of slots 68 and protrusions 70 serving to limit the axial forward movement thereof.

Flexible socket assembly 10 is particularly well suited for use in conjunction with automated assembly line apparatus operative to drive threaded fasteners such as nuts or bolts.

One such type of apparatus is designed to simultaneously drive a plurality of wheel securing lug nuts or bolts to secure a vehicle wheel to an axle assembly. In such apparatus the axle assemblies are positioned relatively accurately with respect to the driving apparatus, however, there often may be slight variations therebetween thus preventing a straight axially aligned driving engagement between the lug nut/bolt and driving socket. For example, in one application, the same driving apparatus is utilized to secure both front and rear wheels.

However, the front wheels are positioned with a positive camber wherein the lug nuts/bolts are angled or face downwardly and the rear wheels are positioned with a negative camber wherein the lug nuts/bolts are angled or face upward. The present invention, however, read ily accommodates such variations via the spring loaded ball and socket joint and spring loaded floating socket member. As best seen with reference to Fig. 4, flexible socket assembly 10 is shown positioned to engage an axially offset nut. As illustrated therein, the rotational axis A of the driving apparatus with which socket assembly 10 is to be utilized will lie in an angled and radially offset relationship to the rotational axis B of socket member 18.Because the socket member 18 is in axial alignment with the axis of the threaded fastener, the possibility of excessive wear between the nut/bolt and bore 72 due to shifting movement thereof is substantially reduced.

Further, this self-aligning feature of the socket assembly also reduces the possibiiity of cross threading engagement of the threaded fastener. It should be noted of course that socket assembly 10 may also easily accommodate a situation wherein the axis of the driven and driving members are positioned in parallel radially offset relationship as well as both coaxial relationship and conventional an gular relationship.

As illustrated, the embodiment shown in Figs. 1-4 is designed to enable quick and easy replacement of the socket member 18 by merely unthreadinhg housing 16 from the forward end of intermediate connector member 14 and thereafter rotating socket member 16 a few degrees so as to move protrusions 70 through the circumferential extending portion 66 of the slot 62 whereby it may then be axially withdrawn from housing 16 via slot portion 64 and a new socket member 16 inserted in like manner. As thus constructed, this embodiment offers very easy and quick socket replacement but may only be utilized in applications requiring a single rotational drive direction as otherwise socket member 16 will not be returned to a full axially forward position.An alternative embodiment is illustrated in Fig. 5 which incorporates a modified housing 16' and socket member 18', it being understood that the remaining components incorporated therein are identical to the components described above.

In the embodiment of Fig. 5, flexible socket assembly 86 incorporates a housing 16' which is substantially identical to housing 16 described above except that in place of generally Z-shaped circumferentially spaced slots 62, housing 16' incorporates four circumferentially spaced axially elongated slots 88.

Similarly, socket member 18' is substantially identical to socket member 18 above except that rather than providing integrally formed protrusion 70 thereon, socket member 18' is provided with a plurality of bores 90 positioned in substantially equally circumferential spaced relationship. A plurality of threaded stud members 92 are also provided which are designed to be received within each of the bores 90. Thus, in order to assemble or replace socket member 18', the socket member is first inserted into housing 16' whereupon the respective studs 92 are inserted through slots 88 and threaded into respective bores 90. Because slots 88 extend only in the axial direction and do not incorporate any circumferentially extending portion such as portion 66 of slots 62, socket assembly 18' is well suited for use in driving fasteners in either direction of rotation.The other features and manner of operation are all substantially the same as described above with reference to flexible socket assembly 10 except that suitable locking means must be provided to prevent unthreading of the threaded connection between housing 16' and connector member 14' such as for example a suitable pin radially pressfitted within aligned openings in housing 16' and connector member 14' or the like. It should be noted, however, that while flexible socket assembly 86 has been described utilizing threaded studs 92 on the socket member 18' to prevent relative rotation between housing 16' and socket member 18', other arrangements may be substituted therefor such as depressible spring loaded protrusion for example. The principle objects to be met by studs 92 in this embodiment are that they be movable into and out of engagement with the closed ended slots 88 in housing 16' so as to allow for replacement of the socket member 18' as well as have sufficient strength to transmit the torque forces from the housing to the bolt/nut driving socket member.

Thus as may now be appreciated the present invention provides a unique flexible socket assembly which is particularly well suited for accommodating situations wherein the axis of rotation of the driving and driven members are radially offset from each other and also offers the advantage of relatively quick and easy replacement of the relatively inexpensive socket member thereby enabling extended use of the remaining components of the assembly.

Claims (12)

1. A flexible compliant socket assembly comprising: a first pair of members movably interconnected by a ball and socket joint, one of said members having means for coupling said socket assembly to a driving tool, a housing member having a bore therethrough connected to the other of said members; a socket member loosely retained within said bore, said socket member having an opening at one end thereof for receiving a portion of a fastener to be torqued thereby; and drive means cooperating between said housing and said socket member for transmitting torque from said driving tool to said socket member whereby said fastener may be torqued.

2. A socket assembly as set forth in claim 1 further comprising first aligning means for urging said socket member into axial alignment with said one of said first pair of members.

3. A socket assembly as set forth in claim 2 further comprising second aligning means for urging said first pair of members into coaxial relationship.

4. A socket assembly as set forth in claim 1 wherein said socket member is retained within said bore and said drive means operates between said housing and said socket member so as to allow said socket member to be simultaneously movable with respect to said housing about two substantially perpendicular axis.

5. A socket assembly as set forth in claim 4 wherein said socket member is also movable axially within said bore.

6. A socket assembly as set forth in claim 5 further comprising biasing means acting between said other of said members and said socket member, said biasing means being operative to urge said socket member toward one end of said housing and into coaxial alignment with said other of said members.

7. A socket assembly as set forth in claim 6 wherein said biasing means comprise a helical coil spring.

8. A socket assembly as set forth in claim 1 wherein said drive means comprise a plurality of circumferentially spaced generally radially extending projections provided on the periphery of said socket member, said projections being received within slots provided in said housing.

9. A socket assembly as set forth in claim 1 wherein said socket member includes means within said opening for frictionally engaging said portion of said fastener.

10. A socket drive assembly comprising: a first elongated housing member having a bore extending longitudinally therethrough and a plurality of circumferentially spaced slots provided on the peripherty thereof; a socket member loosely disposed within said bore, said socket member including a fastener receiving recess in one end thereof and a plurality of generally radially outwardly extending projection spaced around the outer periphery thereof, said projections being received within said slots; a coupling member threadedly connected to said housing member; biasing means extending between said coupling member and said socket member and operative to urge said socket member in coaxial relationship with said coupling member; a drive member having one end connected to said coupling member by means of a ball and socket joint; ; a sleeve member surrounding a portion of said drive member; and second biasing means extending between said sleeve member and said drive member, said biasing means being operative to urge said drive member and said coupling member into coaxial relationship.

11. A socket assembly constructed and arranged to operate substantially as hereinbefore described with reference to and illustrated in the accompanying drawings.

12. A socket drive assembly constructed and arranged to operate substantially as hereinbefore desribed with reference to and as illustrated in the accompanying drawings.