Snap-on spanner wrench

[57] ABSTRACT

A tool for threading and unthreading a plug member having a grooved nipple; the tool is provided with a member having a bore adapted to receive the nipple; movable ball detent elements are provided about the lower end of the bore for engaging the grooved portion of the nipple; a spring biased movable member disposed about the bore is provided with cam surfaces for urging the ball detent elements into engagement with the groove of the nipple whereby backing off of the tool from the plug is prevented; the movable member is provided with diametrically disposed pins for engaging bores in the face of the plug so that rotation of the movable member will effect rotation of the plug.

Claims, 5 Drawing Figures

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PATENTED SEP 2 6 1972

3,693,484

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3,693,484

SNAP-ON SPANNER WRENCH

BACKGROUND OF THE INVENTION

The present invention relates generally to improvements in spanner wrenches and similar tools and more particularly to novel means for maintaining the tool in operative engagement with the element being manipulated.

The use of spanner wrenches to thread and unthread elements such as studs, caps, plugs or the like in various mechanical assemblies has long been known in the art. Generally, these devices are provided with a plurality of studs or pins so positioned on the tool so as to permit their insertion into bores or sockets formed in the element to be rotated. While the cooperation between the pins and associated sockets has proved more advantageous than the use of the conventional screwdriver or jaw-type wrench, such devices have not proven entirely satisfactory under all conditions of use for the reasons that considerable difficulty has been experienced in initially aligning the pins and sockets to effect their interengagement particularly where the element to be rotated is located in a position where it could not be observed by an individual. Moreover, the tools of the prior art have generally lacked means for maintaining the pins in engagement with the sockets. This has proved to be particularly troublesome in situations where the force of gravity could not be relied upon to maintain such engagement, for example, where the element to be rotated was disposed in a vertical plane or on the underside of an assembly. Another disadvantage of the prior art devices flows from the lack of means for keeping each of the pins of the tool in full engagement with their respective sockets so that when a pin is not fully inserted, bending stresses will be exerted thereon tending to weaken and eventually snap off the pin.

The device of the present invention avoids the foregoing disadvantages by providing means for maintaining the tool in proper engagement with the element at all times during the rotation operation, the engagement and disengagement of which can be effected easily·

SUMMARY OF THE INVENTION

The tool of the present invention is adapted to cooperate with a cap or plug having a flat end face from which a nipple having an annular groove perpendicularly extends. The tool comprises a shaft-like member having an upper portion, the exterior of which is hexagonal in cross-section and a lower portion having a cylindrical bore. Adjacent the open end of the bore there are provided a plurality of circumferentially spaced slots formed therethrough, each having a ball carried therein. The slots are formed to permit the balls to partially project into the bore. A ring-shaped member is disposed about the lower portion of the shaft-like member and is mounted to move longitudinally thereof. The upper interior portion of the ringshaped member is formed hexagonally in cross-section to cooperate with the hexagonal surface of the upper portion of the shaft-like member. A radially interiorly extending flange is provided around the interior wall of the lower portion of the ring-shaped member to function as a cam surface for urging the ball elements into their projecting position. The lower face of the ring shaped member is provided with pins projecting therefrom for cooperation with sockets formed in the face of the plug. Spring means are suitably disposed between a portion of the shaft-like member and the ring-like member to maintain the ring-shaped member in a position where the flange will urge the ball elements into their projecting positions.

With the foregoing arrangement, when the nipple is inserted into the bore of the shaft-like member, the tool will be prevented from moving away from the plug by virtue of the engagement of the ball elements with the groove of the nipple; yet rotation of the tool about its longitudinal axis will be permitted so that the pins of the ring-shaped member may be brought into engagement with the sockets of the plug.

Accordingly, an object of the present invention is to provide a spanner wrench having improved means for preventing the backing off of the tool from the element to be rotated during use.

Another object is to provide a tool having means for facilitating the insertion of the plug engagement pins into the sockets of the associated plug.

A still further object of the present invention is to provide a tool capable of maintaining the pins in engagement with the sockets irrespective of the gravitational force exerted on the tool.

Another object of the present invention is to provide a spanner wrench which is inexpensive to manufacture, yet durable enough to withstand long use.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which:

FIG. 1 is an elevational view partly in section of the tool of the present invention and a plug and nipple for cooperation with the tool;

FIG. 2 is an elevational view partly in section showing the insertion of the nipple into the bore of the tool;

FIG. 3 is an elevational view partly in section illustrating the position of the elements when the nipple is fully inserted into the bore of the tool;

FIG. 4 is an enlarged sectional view in elevation of the ball detent means of the present invention; and

FIG. 5 is a view taken along lines 5—5 looking in the direction of the arrows in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein like reference numerals designate like parts throughout the several views, there is illustrated in FIG. 1 a spanner wrench 10 of the present invention positioned above a cylindrical plug 12 having a flat circular end face 14. A generally cylindrical nipple 16 is attached to the plug 12 at the center of end face 14 and is formed with an annular groove 18. Pin receiving sockets 20 are formed in the end face 14 along a diameter thereof and are equidistantly spaced from the nipple 16. The nipple 16 may be attached to the plug by any suitable means such as threaded connection shown in phantom lines at 22. It will be understood that the illustration of the plug is only by way of example and other elements such as threaded studs, caps, and the like may be adapted for use with the tool of the present invention.

3,693,484

The tool 10 consists of a shaft member 24 having an upper portion with a hexagonally shaped exterior surface as is more clearly shown in the cross-section view of FIG. 5. The lower portion of member 24 is formed with a cylindrical bore 26 having a diameter and longitudinal dimension such that the nipple 16 may be snugly inserted therein. The wall of the bore 26 is provided with a plurality of circumferentially spaced slots 28 therethrough spaced a distance from the opening 26 such that when the nipple is fully inserted into the bore 26, the slots will be positioned adjacent the groove 18 of the nipple 16. Ball bearings, one of which is indicated at 30, are disposed in each of the slots 28. As is mote clearly seen in the enlarged view of FIG. 4, the interior edge of each of the slots 28 is provided with an inwardly tapering circumferential abutment stop 32 provided for the purpose of limiting the extent to which each of the ball bearings projects into the bore 26.

Referring again to FIG. 1, a ring member 34 is disposed about the lower portion of member 24. The upper portion of the interior wall of ring member 34 is hexagonally shaped in cross-section, as shown at 36 in FIG. 5, to interengage with the exterior surface of the upper portion of member 24 so that they may be rotated in unison. A radially interiorly extending flange 38 is formed about the lower portion of the interior wall of ring member 34. A coil spring 40 is located about the lower portion of member 24 having one end engaging shoulder 42 formed on the lower portion of member 24 and its other end engaging one side of the flange 38. A snap ring 44 is disposed in a groove about the exterior wall of the lower portion of member 24 adjacent the opening of the bore 26 to limit the downward movement of ring member 34 under the influence of the spring 40. Shoulder 46 on ring member 34 and shoulder 48 on member 24 are arranged to limit the upward movement of ring member 34 relative to member 24.

Ring member 34 is provided with an end face 50 from which pins 52 project in a direction parallel to the longitudinal axis of the bore 26. The pins 52 are spaced so that they may be brought into registry with the bores 20 formed in the 'end face 14 of plug 12. The pins 52 may be held in place by any suitable means such as by press fitting, a threaded connection, or the like. If desired, the pins may be releasably engaged by the bores in the end face 50 so that they may be replaced easily in the event they become worn or broken.

The operation of the tool of the present invention will now be described with particular reference to FIGS. 2 and 3.

In order to insert the nipple 16 into bore 26, an individual must first grasp member 24 in one hand and move ring member 34 with the other hand back along the lower portion until shoulders 46 and 48 abut each other as shown in FIG. 2. In this disposition, spring 40 will be compressed and flange 38 will no longer obstruct the exterior openings of the slots 28 so that as the nipple 16 is inserted into the bore 26, the top side of the nipple will engage the ball bearings 30 and move them out of the bore to a retracted position. With the elements arranged as shown in FIG. 2, the ball bearings 30 are prevented from falling out of their respective slots 28 by virtue of their engagement with the tapered underside 54 of flange 38. Also, as illustrated in FIG. 2, the ball bearings 30 are being constantly urged against the nipple 16 by virtue of the spring force transmitted through surface 54 which is functioning as a cam surface so that when the slots 28 are positioned adjacent groove 18 of nipple 16, the ball bearings 30 will be moved into engagement therewith while the pins 52 engage end face 14 of the plug 12. Upon the rotation of ring member 34 about the longitudinal axis of the nipple 16, pins 52 will be brought into registry with the sockets 20 whereupon member 34 will snap downwardly into engagement with the end face 14 as shown in FIG. 3. With the elements disposed as illustrated in FIG. 3, it will be noted that surface portion 56 of flange 38 has been moved into contact with the ball bearings 30 to maintain the ball bearings in their projected position in engagement with the groove 18 of nipple 16, thereby preventing longitudinal movement of the tool 10 with respect to the nipple 16. The tool may then be rotated about the longitudinal axis of the nipple 16 to rotate the plug 12 in its bore. A socket 58 is provided in the upper end of member 24 for cooperation with a socket wrench in the event that a greater amount of torque is required to effect removal of the Plug.

Removal of the tool 10 from the plug is accomplished by moving the ring member 34 back to the position shown in FIG. 2 to allow the ball elements to move to their retracted positions.

It will be understood from the foregoing that various modifications in the present invention may be effected without departing from the spirit and scope of the novel concepts as defined in the appended claims.