Abstract:
An adjustable extension for driving tools has a telescoping body. The telescoping body has an outer member which may be driven by a conventional driver, such as a ratchet handle or by a powered driver. The outer member drives a longitudinally extending inner member which is telescoped within the outer member. The inner and outer members have detents or a rack and pawl to firmly position the members at the desired length. The inner and outer members may be spaced to prevent binding of the elements when subjected to heavy torque loads and have stops to limit the telescoping movement of the elements.

Description:
This application is a continuation-in-part of U.S. application Ser. No. 10/223,870, filed Aug. 20, 2002 now abandoned, for Adjustable Extension for Socket Wrenches. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to mechanical tools for driving fasteners and particularly to extensions for tools for driving fasteners. 
   2. Brief Description of the Prior Art 
   It is common to have rod like extensions for tool drivers, such as conventional socket wrenches and the like. Often it is necessary to have a set of extensions of graduated lengths to fit the variety of conditions presented by the particular mechanical arrangement being constructed or repaired. In dealing with a single job it may be necessary to switch extensions several times to complete the work required. 
   As an alternative, a number of adjustable extensions have been considered. The disclosures of the following U.S. patents are incorporated by reference herein: U.S. Pat. Nos. 2,438,633, 2,963,930, 4,344,340, 4,367,663, 4,905,548, 5,033,337, 5,138,911 and 5,927,161. 
   BRIEF SUMMARY OF THE INVENTION 
   In view of the above, it an object of the present invention to provide a non-binding, telescoping adjustable extension for driving tools. Other objects and features of the invention will be in part apparent and in part pointed out hereinafter. 
   In accordance with the present invention, an adjustable extension for socket wrenches is provided. The adjustment is achieved by a telescoping arrangement of the parts of the device that permits the device of the invention to take the place of several extensions of fixed lengths. In addition, the adjustment may be achieved without removing the extension from the driven tool, such as a socket wrench, and from the driver, such as an air wrench, a ratchet driver or other driver such as an Allen key. This function is especially useful if a space in which the work is being performed requires a plurality of extensions as a nut or bolt is tightened or loosened. 
   The telescoping arrangement of parts preferably uses an outer sleeve having a central bore. The sleeve is adapted to be driven by a conventional driver, such as an Allen key, a ratchet handle, an air wrench or the like. A retractable inner connector is received in the central bore and is adapted to telescope to a variety of lengths, as disclosed herein. The retractable inner connector is adapted to move axially along the length of the outer sleeve in a non-binding manner. The retractable inner connector includes a rack which is engaged by a pawl carried by the sleeve. Pawl locks the retractable inner connector in selected telescoping position within the sleeve. 
   The invention summarized above comprises the constructions hereinafter described, the scope of the invention being indicated by the subjoined claims. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated, corresponding reference characters refer to corresponding parts throughout the several views of the drawings in which: 
       FIG. 1  is a perspective view of an adjustable extension in accordance with the present invention with a conventional ratchet driver and socket wrench; 
       FIG. 2  is a cross-sectional view of the device shown in  FIG. 1  taken along the plane  2 — 2  of  FIG. 1 ; 
       FIG. 3  is a fragmentary perspective view of a distal end of the adjustable extension; 
       FIG. 4  is a cross-section taken along the plane  4 — 4  in  FIG. 2 . 
       FIG. 5  is a cross-section taken along the plane  5 — 5  in  FIG. 6 ; 
       FIG. 6  is a cross-section taken along the plane  6 — 6  in  FIG. 3 . 
       FIG. 6A  is similar to  FIG. 6  but showing the pawl released from the ratchet teeth; 
       FIG. 7  is a perspective view of an alternative embodiment of the outer sleeve portion of the invention; 
       FIG. 8  is a perspective view of an alternative stop as used in the outer sleeve shown in  FIG. 7 ; and, 
       FIG. 9  is a partial front plan view of an alternative embodiment of the inner connector of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the drawings more particularly by reference character, as shown in  FIGS. 1 and 2 , reference numeral  10  refers to a conventional ratchet driver. Ratchet driver  10  is positioned in a receiver  11  to indirectly drive a conventional socket wrench  12 . Ratchet driver  10  is connected to socket wrench  12  by an adjustable extension  14 . Adjustable extension  14  has a longitudinally extending inner connector  16  and an outer sleeve  18 , as shown, and receiver  11  is incorporated in the outer sleeve  18 . 
   Inner connector  16  terminates in a distal driving end  20  which may be received in a complementary shaped recess  22  in socket wrench  12 . The shape of recess  22  and distal driving end  20  of inner connector  16  may be square in cross-section. However, it will be appreciated that other shapes may be used; for example, the complementary driving connection may be hexagonal, star shaped and the like. 
   Distal driving end  20  of inner connector  16  may also be provided with a spring biased detent  24  which provides a firm removable connection between distal driving end  20  of inner connector  16  and recess  22  of socket wrench  12 . As is known in the art, recess  22  of socket wrench  12  may have a relieved portion, not shown, which cooperates with spring biased detent  24  to provide a firm removable connection between distal driving end  20  of inner connector  16  and socket wrench  12 . Also as is known in the art, socket wrench  12  has a second recess  26  which has a complementary shape for receiving a cooperating fastener, such as a bolt head or a nut, not shown. 
   A proximal driven end  28  of inner connector  16  also has a driving shape, which in  FIG. 4  is shown as square in cross-section. As described above, this cross-sectional shape may also be of other configurations, such as hexagonal, star shaped, or some other complementary driving shape. Proximal driven end  28  of inner connector  16  may also be provided with a spring biased detent  29  which cooperates with outer sleeve  18  to form a firm removable connection, as described herein. An intermediary portion  30  of inner connector  16  is formed to be narrower than proximal driven end  28  and distal driving end  20  and includes a rack  31 . Rack  31  may encircle intermediary portion  30  or be formed as a longitudinal strip, as shown. In a preferred embodiment intermediary portion  30  of inner connector  16  may be circular in cross-section. 
   As illustrated in the drawings, outer sleeve  18  is substantially tubular, having a cylindrical outer surface  32  and a central cavity  33  which extends longitudinally through outer sleeve  18 . The cross-section of central cavity  33  is complementary to the shape of proximal driven end  28  of inner connector  16 ; that is, the cross-sectional shape of central cavity  33  is generally non-circular. As shown in  FIG. 4 , central cavity  33  is square in cross-sectional shape and has four longitudinally extending inner walls  34 , as shown. However, other complementary driving shapes may be used, including hexagonal, star shaped and others, as described above. It will be appreciated that outer surface  32  of outer sleeve  18  may also be of a non-circular configuration, such as a polygon. 
   The interior of outer sleeve  18  may be smooth or outer sleeve  18  may have one or more recesses  35  formed in the interior of outer sleeve  18 , as seen in  FIG. 4 . Recesses  35  may cooperate with spring biased detent  29  in proximal driven end  28  of inner connector  16  to form a firm removable connection between outer sleeve  18  and inner connector  16 . As an alternative embodiment shown in  FIG. 7 , outer sleeve  18  may have one or more transverse bores  36  which cooperate with spring biased detent  29  in proximal driven end  28  of inner connector  16 . Recesses may also be formed in outer sleeve  18  to cooperate with a spring biased detent  38  in ratchet driver  10 , or in other driving means. The terminal bore  36  adjacent to proximal end  42  of outer sleeve  18  may cooperate with spring biased detent  38  of ratchet driver  10 , or with another conventional driver, not shown. 
   As noted herein, intermediary portion  30  of inner connector  16  may be narrower than proximal driven end  28  and distal driving end  20  of inner connector  16 . When inner connector  16  is received in central cavity  33  of outer sleeve  18  intermediary portion  30  of inner connector  16  is out of substantial contact with outer sleeve  18 . This spaced relationship between outer sleeve  18  and intermediary portion  30  of inner connector  16  permits the inner connector to move freely within outer sleeve  18  to the desired extension length. Further, the spaced relationship between outer sleeve  18  and inner connector  16  provides sufficient compliance to avoid binding, especially when large torque loads are placed on the device of the invention. For example, if there was a close fit along the full extent of inner connector  16  and central cavity  33  of outer sleeve  18 , the distortion from a large torque load could cause inner connector  16  to bind in outer sleeve  18  and potentially jam inner connector  16  in outer sleeve  18 . This jamming could then interfere with the operation of the device by preventing a desired change in the extension length during use. 
   As shown in  FIG. 2 , outer sleeve  18  may have a stop  43  placed in central cavity  33  of outer sleeve  18 . Stop  43  may be cast in central cavity  33  of outer sleeve  18  or formed by other conventional means, such as pressing stop  43  into central cavity  33 . Stop  43  prevents the inner connector from completely telescoping into central cavity  33  and becoming jammed therein. 
   A circular stop  44 , seen in  FIGS. 7 and 8 , may be attached to a distal end  45  of outer sleeve  18 . Circular stop  44  has an opening  48  which receives inner connector  16  therethrough. As shown in  FIGS. 7–8 , opening  48  is circular and is sized to collar intermediary portion  30  of inner connector  16 , but not to bind inner connector  30 . When extension  14  of the invention is fully contracted, distal driving end  20  of inner connector  16  abuts against circular stop  44  and is prevented from fully entering central cavity  33  of outer sleeve  18 . As shown in  FIG. 9 , inner connector  16  may have a modified distal driving end  20 . An abutting member, such as a flange or shoulder  50 , may be added to distal driving end  20  of inner connector  16 . Flange or shoulder  50  abuts against distal end  45  of outer sleeve  18 , or against circular stop  44 , when inner connector  16  is retracted into central cavity  33  of outer sleeve  18 . 
   With reference to  FIG. 8 , circular stop  44  may be formed of a plurality of parts, such as the two elements  52  and  54  to simplify the assembly of extension  14 . Proximal driven end  28  of inner connector  16  is first inserted into central cavity  33  of outer sleeve  18 . Elements  52  and  54  are then attached on distal end  45  of outer sleeve  18  by any conventional means, such as by the use of adhesives, by welding, by using fasteners such as machine screws and so forth. Distal end  45  of outer sleeve  18  may be provided with an upstanding flange, not shown, to encompass the periphery of circular stop  44 , if desired. 
   As shown in the drawings, rack  31  is formed along intermediate portion  30  of inner connector  16 . Rack  31  includes a plurality of teeth  56  and a pawl  58  which fits into one or more of teeth  56 . When teeth  56  are not sloped as shown in  FIG. 6 , pawl  58  prevents either forward or backward movement of inner connection  16 . When teeth  56  are sloped (i.e., ratchet teeth) and depending on the direction of the slope, pawl  58  will allow forward or backward movement of intermediate portion  30  in sleeve  18  but resist movement in the opposite direction. Pawl  58  as shown in the drawings is pivoted on a spring biased axle  60  which is received in a window  62  formed in sleeve  18  near or at distal end  45 . Pawl  58  includes an extension  64  which is notched  66  into sleeve  18 . A spring  68  acting against extension  64  and notch  66  biases pawl  58  into engagement with teeth  56 . To release pawl  58 , as shown in  FIG. 6A , a downward pressure is applied on extension  64  compressing spring  68 . Intermediate portion  30  can then move freely in sleeve  18 . 
   Extension  14  of the invention may be made from conventional durable and sturdy material such as stainless steel, tool steel or tool alloys such as chrome vanadium which does not rust. It may be fabricated by a wide variety of conventional metal working techniques, including but not limited to extruding, machining, casting, forging, welding and combinations of these techniques. 
   In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.