Abstract:
A coupling for interconnected members uses a pin positioned in holes perpendicular to the axes of the members, where the holes in each are formed and arranged by angular displacement so that the pin rotationally forces the members against one another for an interference fit.

Description:
BACKGROUND OF THE INVENTION 
     This is a continuation in part of my U.S. Pat. No. 4,938,107 issued July 3, 1990 entitled &#34;Wedge Locking Socket Device&#34; which is incorporated by reference herein. In summary my tools are designed to provided advantages of ease of operation, increased utility, ease of maintenance and better value for products used in the typical environment of the mechanic, particularly the automotive mechanic. 
     Earlier embodiments of my inventions involved in part arrangements which could be utilized to effectuate the locking of a drive socket to my tool and the release of that socket for removal or replacement. The &#34;Wedge Locking Socket Device&#34; incorporates improvements in function and economy of production through the camming engagement of a series of retainer balls and a novel wedging control bar to provide wedging between the bar and balls for effectively locking an associated socket and includes a securement portion as a separate structure from an extension shank. The advantage in the use of a wedging control bar is that the forces contributing to retention are increased under load. 
     Advantages of separate securement portion or stub body include greater choices in manufacturing operations and materials, and economies in the aftermarket as where either the securement portion or shank requires repair or replacement. This latter embodiment has been further improved by the use of angularly displaced offset hole in the driving and driven portion and a lateral wedging relation with a pin extended therethrough as will be further discussed in this application to include advantages in the fit between the components, the precision obtainable in operation, the &#34;feel&#34; to the user and improvements in manufacture. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective cut away view of my socket locking extension. 
     FIG. 2 is a sectional view of an embodiment in which a separate securement structure is attached to a drive shank. 
     FIG. 3 is a sectional view of the angularly offset coupling taken at a transverse line 3--3. 
     FIG. 4 is a sectional view of the angularly offset pin coupling corresponding to FIG. 3 with a rolled pin disengaged. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates a socket locking extension with a driven portion (11) extension shank (9) and square or multi-sided driving portion (12). The driving portion (12) fits into a complementary socket (21) for imparting rotational movement. A slot or channel (10) is formed in the surface of the shank and extends into one face or wall of the drive portion (11). 
     A control bar (14) which has an outer surface (13) is carried in a control bar channel. A raised portion or spur (16) extends outward from the outer surface (13) and fits into sleeve (15). The sleeve has internal annular engagement elements or flanges. In this embodiment these constitute an inner annular ring (28) and terminal annular ring (29) of the sleeve defining an annular groove (30) between them. This preferred embodiment does not foreclose the use of other methods of engagement. The forward motion of the sleeve toward the driving end is limited by a circular clip (18) as in prior embodiments. Rearward movement, limited by a limiting collar (52) which engages the rear edge of the sleeve. This collar may be formed as a raised ring portion of the shank material and enables the engagement of a second shank (83) as will be more fully described. In the preferred embodiment the sleeve may be covered with a friction increasing surface pattern such as knurling or other arrangements making the sleeve easy to grip and retract. 
     FIG. 2 shows the securement portion of the tool carried on a truncated body (80) of length sufficient to carry the sleeve (15), provide for the stop portion or collar (52) limiting retraction of the sleeve and is adapted to receive the driving end (81) of a second shank (83) in corresponding recess (82) in the truncated body. Operation of the retainer mechanism carried on the truncated body is unchanged from the embodiments discussed in connection with my co-pending application. The recess for driving the truncated body by the second shank (83) is defined by walls that correspond to the driving portion (81) of the second shank (83). Shanks (9) and (83) are coaxial. 
     The truncated body (80) is attached to the second shank (83) in a semi-permanent manner through the insertion of a pin (84) in a hole or aperture (85) extending through one wall (86) of the truncated body&#39;s recess, through a corresponding hole or aperture (88) in the driving portion (81) of the second shank (83) and through the opposing wall (87) of the driven recess of the truncated body. This pin may be inserted and maintained in place by a compression fit thereby resulting in a unitary extension tool. 
     The use of the arrangement in FIG. 2 permits the use of dissimilar alloy metals in the truncated body and second shank, the use of differential treatment as by heat treating of the respective truncated body and second shank and repair or replacement of either the truncated body or the second shank without requiring replacement of both. A further advantage is that production can be streamlined because of the previous mentioned material and heat treatment flexibility. Related to this is the possibility of using closer tolerance on the truncated body while the second shank only needs such close tolerance where it connects to the truncated body. Further, the truncated body-second shank arrangement permits adaptation of various length extensions which may be more easily conformed to specific consumer needs. The space (90) between the wall (86) of the truncated body and the walls (86) and (87) which form the driving end (81) of the second shank are required by manufacturing tolerances, and are exaggerated here for illustration. 
     FIG. 3. is a sectional view showing the interrelation between the male end of the second shank (83) and the recess of the body or first shank (80). It has been determined that at normal manufacturing tolerances, to permit the longitudinal insertion of the second shank into the recess, using parallel holes in the respective walls and driving portion, and using various pin configurations, an unacceptable degree of &#34;play&#34; is present. Disadvantages the prior art configurations include: inaccuracy in application of calibrated torque, added stress on the pin through repeated cycling of load and no-load conditions, and generally the presence of lost motion in taking up the tolerances in operation. Pressing the pin (84) in place with hole or aperture (85) and hole or aperture (88) angularly offset pre-loads the assembly, forming an interference fit shown where corners (91), (92) and (93), (94) contact. All outside corners of shank (83) contact the walls of recess (82) near the respective inside corners. 
     FIG. 4 shows the first and second shanks in their relative positions prior to pressing the pin (84) in place. The invention uses in the preferred embodiment, a rolled pin (84) which is chamfered at the insertion end (95). Since the truncated body is the element designed for higher precision manufacturing, the hole or aperture (85) through the walls is angularly offset by rotating in a clockwise direction. An interference fit will result when the pin is pressed in place. It has been found that optimum rotation or angular offset (a) should be determined to take up all space or clearance provided for by the maximum range of tolerances specified, and therefor closer tolerances will simply result in a superior fit at slightly greater pre-load. For a typical 3/8&#34; drive standard tool, a 2° rotation is preferred. 
     The rolled pin in particular, has sufficient elasticity or flexibility and strength to both impart the pre-load when pressed in, yet will permit counterclockwise rotation with little adverse effect, the pin either bearing the torque itself, or distorting sufficiently to permit the bearing or contact at outside/inside corner pairs (91), (92), and (93), (94) of the respective walls on one another. A pin of different configuration, such as a solid pin, can perform the function without departing from the invention, providing equivalent performance. 
     The chamfer on the pin end (95) provides for a finished end, and includes centering properties enabling greater ease in the placement and pressing of the pin, and the imparting of the rotation of the second shank within the recess without back lash for greater efficacy. Notwithstanding the preferred embodiment, other pins end shapes, such as a radiused end, or a taper, may perform the function without departing from the invention. 
     In driving the pin through the offset apertures (88), (85) in the shank (83) and the truncated body portion (52) the pin or the tool parts, depending upon their metallurgy, will slightly deform and provide a tight interlock of these parts with each other at the contacting surfaces 91-94 as shown in FIG. 3.