Abstract:
A reversing ratchet wrench especially suited for mass production and having few easily machinable parts. The pawl and driver are provided with overlapping covers which retain the pawl and protect the engaging teeth. The driver cover is flush with the wrench head for added convenience, yet makes no contact because the driver is supported on a driver skirt. Hence, the wrench is highly impact resistant. A unique retaining clip for retaining the driver allows convenient replacement of the pawl cap/reversing lever without removal of the pawl. Likewise, the wrench can be completely disassembled without special tools, thereby facilitating point-of-sale repair.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to hand tools, and more particularly to reversing ratchet wrenches from use with interchangeable socket heads. 
     2. Description of the Background 
     Reversing ratchet wrenches are widely used to apply torque for tightening or loosening nuts and bolts. Conventional wrenches include an elongated handle formed with a head at one end for housing the ratchet mechanism. A ratchet driver is rotatably mounted within the housing in engagement with a toothed pawl. The pawl is selectively engagable by operation of a reversing lever into two driver engaging positions in which the driver is limited to one of clockwise or counterclockwise rotation. 
     The utility of such wrenches largely depends on the design of the reversing ratchet mechanism and the machined head in which it is seated. The design objectives include simplicity and improved manufacturing economy, ease of use, higher strength and durability, conservation of space, protection of internal components, protection of the external reversing lever, and ease of disassembly and repair. 
     U.S Pat. No. 2,978,081 is one example of a ratchet wrench which conserves space while maintaining durability. However, the machining operations necessary to produce the intricate pawl and driver preclude cost-effective mass production. 
     U.S. Pat. No. 4,277,990 discloses a wrench of simpler design which is more suitable for mass production. However, this wrench is exceedingly difficult to disassemble for repairs. 
     U.S. Pat. No. 4,485,700 discloses a wrench design which attempts to minimize both space and cost of manufacture. However, the design incorporates a split ring retainer which hinders disassembly. In addition, both the driver cap and the reversing lever protrude from the wrench head. Consequently, a mechanic cannot easily grip the wrench head to apply pressure while turning. Moreover, the unprotected reversing lever is susceptible to being sheared off and/or inadvertent shifting. The wrench is also prone to clogging by grit and particulates which are drawn between the exposed bearing surfaces. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide a reversing ratchet wrench based on a simple design with few easily machinable parts, the design being especially suited for mass production. 
     It is another object of the invention to provide a more dependable wrench which is also more convenient to use. 
     It is still another object of the invention to provide a highly impact-resistant wrench which is designed to provide inherent protection for all internal parts from clogging by outside dirt and particulates. 
     It is another object of the invention to provide a wrench head design which seats the reversing lever in a recessed pocket, thereby protecting the lever against breakage and inadvertent reversing. 
     It is yet another object of the invention to provide a wrench design which allows convenient disassembly without tools, thereby facilitating point-of-sale repair. 
     According to the present invention, the above-described and other objects are accomplished by providing an improved reversible ratchet wrench. The wrench comprises a unitary gripping handle and head, the head being formed with a cylindrical driver chamber extending between the upper and lower surface, and a cylindrical pawl chamber extending from the upper surface. The driver chamber is rimmed by a driver skirt at the lower surface, and the pawl chamber is closed at the lower surface by a pawl footing which is unitary with the driver skirt. The two chambers communicate along a peripheral area of overlap. A driver is rotatably seated in the driver chamber. The driver further includes a cylindrical ratchet member defined by teeth arcuately spaced around the periphery, a driver cap covering the upper end of the ratchet member and overlying the driver teeth, an annular shank section, and a drive tang extending from the shank for engagement with various sockets. The wrench also includes a retainer for retaining the driver within the driver chamber, and a pawl rotatably seated within the pawl chamber and having teeth selectably engagable with the driver teeth to permit uni-directional rotation of the driver. The pawl also includes a pawl cap covering the pawl teeth and extending into an annular recess between the driver cap and driver toothed-member. Hence, the pawl cap and overlapping driver cap provide a protective cover for the pawl teeth and driver teeth, and the overlying driver cap serves to retain the pawl within the pawl chamber. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects, features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings, in which: 
     FIG. 1 is a perspective view of a wrench body according to the present invention. 
     FIG. 2 is an enlarged version of FIG. 1. 
     FIG. 3 is an assembly diagram of wrench head 10 equipped with the ratchet mechanism of the present invention. 
     FIGS. 4 and 5 illustrate perspective views of the assembled wrench according to the present invention. 
     FIGS. 6 and 7 show a bottom view and top view, respectively, of the assembled wrench according to the present invention. 
     FIG. 8 is a cross-sectional view taken along line A&#39;--A&#34; of FIGS. 6 and 7. 
     FIGS. 9 and 10 illustrate a side view and top view, respectively, of the retaining clip 70. 
     FIGS. 11 and 12 show the manner of insertion of retaining clip 70 according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates a perspective view of a wrench body 2 formed in accordance with the present invention. As shown, a wrench body 2 includes an elongated gripping handle 5, and a head 10 which is adapted to house a ratchet assembly. 
     FIG. 2 is an enlarged view of FIG. 1 which illustrates wrench head 10 more clearly. Head 10 is defined by a generally cylindrical driver chamber 20 and a generally cylindrical pawl chamber 30. Chambers 20 and 30 communicate along an area of overlap. Pawl chamber 30 is substantially closed along the bottom surface of head 10. Driver chamber 20 traverses the upper and lower surfaces of head 10. A peripheral skirt 40, which is formed integrally with head 10, rims the bottom of driver chamber 20. 
     The above-described features which are formed in head 10 are essential to the improved operation of the wrench. Moreover, they are carefully designed to allow machining with a single machine tool. The reversing mechanism is then assembled into head 10. FIG. 3 is a detailed assembly diagram of wrench head 10 equipped with the ratchet mechanism. A narrow bore 32 extends from the rear of pawl chamber 30 at a downward angle into handle 5. The bore 32, which is not is provided with a spring-mounted detent ball of conventional design (not shown). A pawl 50 includes a generally circular pawl cap 52 and unitary reversing lever 56 with an extending stem 54. Stem 54 fits within a toothed member 51, and is keyed thereto such that toothed member 51 can be rotated by reversing lever 56. The rear of toothed member 51 is defined by a dual recess which engages the spring-mounted detent ball protruding from bore 32 (not shown). The front of toothed member 51 is defined by at least two teeth 53 for engaging the peripheral teeth 63 of a unitary driver 60. Toothed member 51 is adapted to fit within pawl chamber 30, and driver 60 is adapted to fit within driver chamber 20. When toothed member 51 is inserted in pawl chamber 30 and driver 60 is inserted in driver chamber 20, pawl teeth 53 engage driver teeth 63 along the area of chamber overlap. Driver 60 is provided with a driver cover 62 extending over driver teeth 63. The driver cover 62 is spaced from toothed section 65 by an annular groove 64 circling therebetween. Driver 60 is also provided with a cylindrical shank section 66 extending from toothed section 63. A second annular groove 67 encircles shank section 66, and a drive tang 68 protrudes from shank section 66 for engaging sockets and other tools. 
     To assemble, the spring-mounted detent ball (not shown) is inserted within bore-hole 32. Pawl 50 is then assembled by attaching pawl cap 52 and reversing lever 56 to toothed pawl member 51. Stem 54 provides a interference fit. Pawl 50 is then brought into engagement with driver 60 such that pawl cap 52 extends into groove 64. Pawl 50 and driver 60 are together inserted within respective pawl and driver chambers 30 and 20 until the bottom of toothed member 51 is seated in bearing relation to the substantially closed bottom of pawl chamber 30, and the toothed section 65 of driver 60 is seated in a bearing relation on driver skirt 40. Shank section 66 of driver 60 extends past driver skirt 40, and protrudes outward therefrom. 
     A retaining clip 70 is then inserted. Retaining clip 70 is provided with a locking C-ring section 72 adapted to fit within annular groove 67 on shank section 66. Retaining clip 70 locks the driver 60 within the driver chamber 20 such that the bottom of toothed section 65 is in bearing engagement with driver skirt 40. A small clearance is maintained on all sides of driver cover 62. This way, driver skirt 40 directly absorbs all downward impacts imparted to driver 60, and upward impacts are transmitted to driver skirt 40 through retaining clip 70. This feature insures superior strength and durability. In addition, this improves the operation of the wrench by limiting the horizontal movement of the driver and eliminating friction which may interfere with the proper engagement of driver 60 and pawl 50. 
     The above assembly confers an additional advantage in that pawl 50 is secured within pawl chamber 30 by the overlapping driver cover 62. Hence, pawl 50 does not require a separate retainer. Moreover, the pawl cap 52 and overlapping driver cover 62 provide a protective seal against grit and particulates which prevents clogging of pawl teeth 53 and driver teeth 63. The bottom surface of wrench head 10 is similarly sealed by closed pawl chamber 30 and driver skirt 40. 
     In operation, the spring-mounted detent ball (not shown) biases pawl 50 into one of two drive engaging positions. The drive engaging position is manually selected by operation of reversing lever 56. In a first position, pawl teeth 53 engage driver teeth 63 to allow driver rotation in a clockwise direction, while preventing counter-clockwise rotation. In a second position, rotation occurs in a counter-clockwise direction and is prevented in a clockwise direction. 
     FIGS. 4 and 5 illustrate perspective views of the assembled wrench. As shown in FIG. 4, the shank section 66 and drive tang 68 extend from wrench head 10. Driver 60 is clamped in place by retaining clip 70 which fits within the annular groove 67 in shank section 66. The retaining clip 70 is provided with a small detent button 76 which rests within through-bore 59 in wrench head 10. 
     FIG. 5 illustrates a top perspective view of the assembled wrench. The upper surface of wrench head 10 is provided with a raised and contoured margin around its periphery. The margin is contoured around the driver cap 62 so that the driver cap sits flush therein. Likewise, the margin is contoured around the sides of pawl cap 52, however, pawl cap 52 is seated beneath driver cap 62 so that the margin rises slightly above pawl cap 52. At the rear of pawl cap 52 the margin terminates, leaving a recessed shelf upon which reversing lever 56 is seated. Pawl cap 52 sits flush with the shelf. The raised and contoured margin provides superior protection for both the driver 60 and pawl 50, and prevents dirt from besieging the teeth. In addition, the reversing lever 56 is well protected within the confines of the recessed shelf formed by the margin, and is less prone to being sheared off or inadvertantly switched. 
     FIGS. 6 and 7 show a bottom view and top view, respectively, of the assembled wrench. The contoured margin around drive cap 62 and pawl cap 52 is clear from FIG. 7. As shown by the arrow, pawl 50 may be switched by reversing lever 56, and reversing lever 56 may be freely maneuvered within the confines of the recessed shelf formed by the margin. 
     FIG. 8 is a cross-sectional view taken along line A&#39;--A&#34; of FIGS. 6 and 7. As shown, toothed member 51 is rotatably seated within pawl chamber 30 in bearing relation to the substantially closed end. Likewise, driver 60 is rotatably seated within driver chamber 20 in bearing relation to driver skirt 40. Pawl teeth 53 are in direct engagement with driver teeth 63. A small clearance is maintained on all sides of driver cap 62. Thus, all axial forces imparted to driver 60 are transmitted to the driver skirt 40 which is unitary with the wrench head. The driver cap 62 is flush with the margin on wrench head 10. Although the driver cap 62 rotates with the driver 60, a mechanic may freely grip the wrench head 10 without being affected by the rotation. 
     Pawl cap 52 extends beneath driver cover 62 and into the annular recess 64 separating the driver cap 62 from toothed section 65. Pawl 50 is sandwiched between driver cap 62 and the bottom of pawl chamber 30. Hence, a separate retainer is unnecessary. 
     FIGS. 9 and 10 illustrate the retaining clip 70, which comprises a locking C-ring section 72 and a finger tab section 74 with detent button 76. Locking C-ring section 72 further includes opposing resilient fingers adapted to fit within and provide locking engagement with recess 67 and shank section 66 of driver 60. Finger tab section 74 of retaining clip 70 comprises two rearwardly extending tabs designed to provide a finger grip. Detent button 76 is adapted to fit within through-bore 59 of wrench head 10. 
     FIGS. 11 and 12 show the manner of insertion of retaining clip 70. As shown in FIG. 8, retaining clip 70 is preferably inserted transversely onto the shank section 66 of driver 60. Since retaining clip 70 protrudes outward from wrench head 10, the entire operation can be accomplished by hand without the special tools typically required for disassembly of conventional wrenches. Reversing lever 70 is then rotated around shank section 66 until detent button 76 becomes engaged in through-bore 59. At this position the retaining clip 70 is axially aligned with the handle of the wrench, and is completely non-intrusive. 
     At this point the wrench is fully assembled and is completely operational. A primary advantage of the above-described construction lies in the convenient assembly and disassembly of the wrench. Disassembly entails disengaging detent button 76 from through-bore 59, rotating retaining clip 70 until finger tab section 74 extends from the wrench head 10, and pulling retaining clip 70 from the shank section 66 of driver 60. At this point, pawl cover 52 can be conveniently replaced without the need to remove the toothed member 51 from pawl chamber 30. If need be, both driver 60 and pawl 50 may be conveniently removed from within respective pawl and driver chambers 20 and 30. The entire assembly and disassembly operation can be effected manually in minutes. Hence, the wrench is highly serviceable, and repairs may take place at the point of sale rather than a special repair depot. 
     Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiment herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically set forth herein.