Socket Wrench Extension

In my co-pending application Ser. No. 502,763, filed June 9, 1983, I disclosed a quick release locking arrangement for a socket wrench extension. That design required manual actuation of the sleeve to mount a socket on the extension. The design did not have push-on mounting capability. In my application Ser. No. 584,512 filed Feb. 28, 1984 I showed a socket wrench extension with a push-on/quick release locking arrangement. While that design provided a function not heretofore available, the construction called for some costly production operations. Accordingly, this invention is directed to reducing the cost of that design while improving the product by way of making it more rugged.

This invention provides a push-on/quick release locking arrangement for a socket wrench extension having a cylindrical body with a square drive end. Transverse offset bores or an inclined bore through the drive end intersects opposed flat faces. Lock balls are mounted in the bore for movement between a lock position in which one of the balls projects from one end of the bore far enough to engage a cooperating cavity in the drive recess of a tool and a release position in which the ball lie within the cross section of the drive end. The end of the bore with the projecting ball is closer to the end of the drive end than is the other end of the bore. An axial groove is provided in the flat face intersected by the other end of said bore. A cylindrical sleeve is mounted on the cylindrical body of the extension. The end of the sleeve remote from the drive end is turned inwardly and a cylindrical slider is fixed in the end of the sleeve closer to the drive end. A spring having a coil captured in a groove in the cylindrical body bears against the slider to bias the slider and sleeve towards the drive end, and a lock tab projects from the slider into the axial groove to overlie the ball when said inturned end of said slider abuts said coil.

This invention also provides an anti-roll feature so the extension will not roll away when laid down.

This invention is an improvement over the slider construction shown in my patent application Ser. No. 584,512 in that the lock tab is part of a slider fixed in the "front" end of a sleeve which is turned in at the "rear" end to capture the biasing spring inside the sleeve. The sleeve per se can be roll formed, machined or molded.

FIG. 1 is an elevation (or plan view) of an extension.

FIG. 2 is a section through an extension engaged with a socket but has the lock between the slider and the sleeve shown in full.

FIG. 3 is a section showing the assembly of the slider in the sleeve.

FIG. 4 is a section showing the assembly of the slider and grip sleeve on the shaft carrying the lock balls.

FIG. 5 is an end view of the slider.

FIG. 6 is a horizontal section on line 6--6 in FIG. 5.

FIG. 7 is a perspective view of the slider.

The extension 10 has a solid round shaft 12 of the desired length. One end of the extension is provided with a recessed driven member 13 which is connected to and driven by the customary handle or impact wrench. The other end of the extension has a square driver 14 dimensioned to fit one of the standard sizes. Driver 14 has a cross bore 16 in which lock means comprising two balls 18, 20 are mounted. The balls are retained by conventional coining operations at each end of the cross bore to reduce the opening to less than the ball diameter. The cross bore is actually two offset cross bores which accept the balls and position the axis of the balls at an angle to a line perpendicular to the axis of the extension. This positions ball 18 closer to the end of the extension so ball 18 will first engage the side 22 of a recess 24 in a socket 26 as the extension moves into the socket recess. The cross bore can be made by drilling two offset holes (as shown) or one inclined hole to house balls 18, 20. The ball axis is angled in either case.

As viewed in the drawings, an axial groove 32 intersects the cross bore. The groove lies in the middle of the flat drive face 34 and has a depth which when added to the length of the cross bore (measured from the bottom of the groove) is equal to the combined diameters of the two balls 18, 20. This permits the balls to lie wholly between the two opposed drive faces when the slider member and sleeve 35 is moved to position the lock tab 36 in an unobstructing position. When the tab 36 is in the obstructing position shown in FIG. 2 ball 18 further from the tab must project to a lock position beyond the flat face of the driver. When the driver is inserted into the recess of a wrench socket the projecting ball 18 will engage a hole 38 in the recess 24 and the tab 36 will be backed up by the opposite wall of the recess to positively lock the socket to the extension until the lock tab 36 is manually withdrawn. A pin having spherical ends could be used instead of the two balls.

When the extension is inserted into the socket 26, the ball 18 will first strike the sloping entry face 22 of the socket. This is a standard sloping face. The ball has to move into the cross bore for the extension to enter the socket. This results in ball 18 pushing ball 20 upwardly (in the drawing) to deflect the tab 36 upwardly where it will project into the path of entry face 22 of the opposite side of the socket recess. Now then, the tab 36 will in turn push the sleeve 35 to the right and clear the space to allow the ball 20 to move into the groove 32 and hence allow ball 18 to move to a non-obstructing position. When ball 18 overlies hole 38 (which could also be a recess in the wall of the socket) spring 46 will push lock tab 36 to the left to occupy the space between ball 20 and the opposing wall and ball 18 engages hole 38 and the socket is locked on the extension.

The present lock tab projects from split slider 40 fixed inside the sleeve 35. The slider 40 is split opposite the portion from which the tab 36 extends. Preferrably this split 43 will be a meandering split shown to minimize passage of dirt into the spring enclosure. The two "sides" of the slider 40 (obviously a cylinder doesn't have sides but if the tab 36 is considered as being at 12 o'clock and the split at 6 o'clock the "sides" at 3 and 9 o'clock are provided with turned out lock tabs 42, 42 which, when brought into registry with cooperating holes 44 in the grip sleeve 35, can engage the holes and lock the slider relative to the sleeve. As the slider is pushed into the sleeve it is squeezed so tabs 42, 42 can enter the sleeve until the tabs can enter holes 44. Then the sides will pop back out to lock the tabs into the sleeve. Before this is done the spring 46 is positioned inside the sleeve as illustrated in FIG. 3 which illustrates the insertion of the slider into the sleeve. Obviously the slider could be withdrawn at this point simply by pulling hard enough to deflect the sides of the split sleeve and pull the slider out. However, the extension end is now inserted (from the spring end of the sleeve) with the balls already in position and retained by coining. Now as the extension moves into position inside the sleeve the far right coil 48 of the spring 46 will snap into the groove 50 in the extension and the sleeve will be limited in its movement to the right relative to the extension by the spring coils going solid. The sleeve can move to the left until the inturned wall 52 of the sleeve engages the spring loop 48 as in FIG. 2. It will be apparent that the extension constitutes a solid back-up to the slider when the parts have been assembled. Thus the slider cannot deflect in to pull the lock tabs 42, 42 out of engagement with the holes 44 in the sleeve. The sleeve assembly is locked onto the extension. It can now be removed only by inserting a small tool and flatening the tabs 42 to clear hole 44.

This arrangement constitutes a great simplification and cost reduction over that of my application Ser. No. 584,512. The grip sleeve now can be a machined part, a roll formed part or can be a molded part. This manner of inserting the slider into the open end of the grip sleeve constitutes a great improvement and cost reduction in addition to providing stronger parts.

The slider can be secured in the grip sleeve in various ways. If the ID of the slider is larger than the body of the extension the sleeve can tilt a little to facilitate pushing the extension into a socket. Instead of the tabs "buttons" can be fixed in a plastic slider to project into holes in the sleeve or the slider can be glued in place, for example.

This improved design retains the same push-on feature of said application. The extension can be pushed onto a socket with a one handed operation. All that is necessary to release a socket is to pull back on the grip sleeve 35 to pull the lock tab away from the ball 20. As a socket on an extension is moved to the work the socket will generally protect against actuating the sleeve in the release direction. As the socket is pulled back engagement of the sleeve with an obstruction will tend to move the slider in the locking direction, not in the release direction. Therefore, the user won't leave the socket behind.

The inturned end 52 of the grip sleeve limits movement of the sleeve to the left when the inturned end 52 engages loop 48 of the spring. The inturned end 52 can be formed by machining, molding, or it can be a ring press forming of the right end of the grip sleeve. The result is the same and the language "inturned end" is meant to embrace all three forms.

This extension embodies a feature not found in the art. The sleeve is provided with 3 circumferentially spaced flats 54 which prevent rolling when the extension is laid down. This avoids the irritating sight (or sound) of the extension rolling away and the problem of relocating it by the user.