Abstract:
A wrench has a handle integral with a ratchet head that defines a chamber having a generally circular sidewall. An annular rotor has radial teeth about an outer surface thereof and is located in the chamber. The rotor teeth engage a single set of teeth extending radially inward from the chamber sidewall. Preferably, the sidewall teeth will be configured to have substantially equal height. Additionally, the two sides of each sidewall tooth that engage the rotor teeth will be configured to be substantially parallel.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to the art of hand tools, more particularly to a bi-directional wrench which operates without the use of a pawl. 
         [0002]    Many types of wrenches have been provided over the years. Wrenches with ratcheting mechanisms are well known to those in the art. The ratchet mechanism in these wrenches permits the wrench to transmit torque in one rotational direction but allows free movement in the other rotational direction. As a result, a user is able to operate the wrench efficiently without removing the wrench from the nut or other driven component each time it is to be indexed. In some cases, ratchet heads may be mounted at both ends of the wrench, and in others a ratchet head will be mounted at one end of the wrench handle with an open box end provided at the other end. 
         [0003]    Generally speaking, ratchet wrenches utilize a pawl having teeth that engage a rotatable gear (or ratchet wheel). The gear is retained within an opening located in the head of the wrench. The ratchet wheel may define a configured opening to directly engage a nut or to receive a particular insert tool. In other cases, the ratchet wheel may carry a tang for use with a variety of different sized sockets. 
         [0004]    Ratchet wrenches that function without the use of pawls are known in the art. For example, U.S. Pat. No. 5,842,391 to Chaconas, incorporated herein by reference, discloses such a wrench. While many existing pawl-less wrenches exist, there exists room in the art for additional novel constructions. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention recognizes and addresses the foregoing disadvantages, and others, of prior art constructions and methods. 
         [0006]    The present invention provides a wrench having a handle integral with a ratchet head. The ratchet head defines a chamber having a generally circular sidewall. An annular rotor having radial teeth about an outer surface thereof is located in the chamber. The rotor teeth engage a single set of teeth extending radially inward from the sidewall of the chamber. Preferably, the sidewall teeth will be configured to have substantially equal height. Additionally, the two sides of each sidewall tooth that engage the rotor teeth will be configured to be substantially parallel. 
         [0007]    Other objects, features and aspects of the present invention are provided by various combinations and subcombinations of the disclosed elements, as well as methods of utilizing same, which are discussed in greater detail below. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings, in which: 
           [0009]      FIG. 1  is a perspective view of a wrench in accordance with an embodiment of the present invention; 
           [0010]      FIG. 2  is a perspective view of the opposite side of the wrench shown in  FIG. 1 ; 
           [0011]      FIG. 3  is a bottom plan view of the wrench shown in  FIG. 1  with the rotor removed; 
           [0012]      FIG. 4  is a perspective view of a rotor in accordance with an embodiment of the present invention; 
           [0013]      FIG. 5  is side elevation cut-away view of the rotor shown in  FIG. 4 ; 
           [0014]      FIG. 6  is a cut-away perspective view of the wrench shown in  FIG. 1  through line  6 - 6 ; 
           [0015]      FIG. 7  is a bottom plan view of the wrench shown in  FIG. 1  with the washer removed; 
           [0016]      FIG. 8  is a bottom plan view of the wrench shown in  FIG. 1  with the rotor teeth indexing over the bore teeth; 
           [0017]      FIG. 9  is a perspective view of a wrench in accordance with an embodiment of the present invention; 
           [0018]      FIG. 10  is an exploded view showing components of the wrench in accordance with an embodiment of the present invention. 
           [0019]      FIG. 11  is a bottom plan view of the wrench shown in  FIG. 9  with the rotor removed; 
           [0020]      FIG. 12  is a perspective view of a rotor in accordance with an embodiment of the present invention; 
           [0021]      FIG. 13  is side elevation cut-away view of the rotor shown in  FIG. 11 ; 
           [0022]      FIG. 14  is a cut-away perspective view of the wrench shown in  FIG. 9  through line  7 - 7 ; 
           [0023]      FIG. 15  is a bottom plan view of the wrench shown in  FIG. 9  with the washer removed; and 
           [0024]      FIG. 16  is a bottom plan view of the wrench shown in  FIG. 9  with the rotor teeth indexing over the bore teeth. 
       
    
    
       [0025]    Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. 
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0026]    It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions. 
         [0027]    Referring to the drawings, and particularly to  FIGS. 1 ,  2  and  3 , a wrench  10  is shown having a handle  12 , a head  14  and a rotor  16 . The body and rotor may be formed from any suitable material, for example one or a combination of steel, alloy, ceramics, polymers, etc. A first end  18  defines head  14 , and a second end  20  defines handle  12 . Head  14  is integrally formed with handle  12  by a neck  22 , and second end  20  has a bore  24  formed therethrough that allows for easy storage of wrench  10  when not in use. Instead of bore  24 , other means of storing wrench  10  may be provided. One skilled in the art will also recognize that as an alternative to bore  24 , a wrench head could be provided at second end  20 . 
         [0028]    Head  14  has a top surface  26  ( FIG. 1 ) and a bottom surface  28  ( FIG. 2 ) located on opposite lateral sides of the wrench. Referring particularly to  FIG. 3 , head  14  defines a bore  30  that (1) extends between top surface  26  and bottom surface  28  and (2) is bounded by an inner circumferential surface  32 . Bore  30  is an oval shape with a single axis of reflection symmetry about a longitudinal axis  13 . The oval shape of bore  30  is generally defined by a first and a second arc located at either end of the oval, both of which are symmetric about longitudinal axis  13 . The first and second arcs are defined by a radius R 1  and R 2  wherein R 1  is substantially equal to R 2 . A center  42  of the first arc and center  43  of the second arc are offset along longitudinal axis  13  by a distance A. In the preferred embodiment offset distance A is 0.050 inches, R 1  is 0.548 inches, and R 2  is 0.548 inches. 
         [0029]    A series of bore teeth  34  are formed on a portion of inner circumferential surface  32 . With reference to a first bore tooth  36 , each bore tooth has a first surface  38  and a second surface  40  that are substantially parallel to a plane that bisects first bore tooth  36  and intersects first arc center  42 . In one preferred embodiment, first surface  38  and second surface  40  are substantially symmetric about a longitudinal center axis of first square-shaped bore tooth  36 . In one preferred embodiment, bore teeth  34  each have a width of 0.041 inches with 0.066 inches of spacing between adjacent teeth. In some embodiments, first surface  38  and second surface  40  are symmetrical about a longitudinal center axis of the tooth yet angled slightly inward such that the base of the tooth is wider than the tip of the tooth thereby creating a trapezoid-shaped tooth. 
         [0030]    Still referring to  FIG. 3 , bore teeth  34  are arranged sequentially on inner circumferential surface  32  from first tooth  36  to a last tooth  44 . These teeth are of substantially equal height and shape and positioned on bore  30  such that bore teeth  34  are symmetric about longitudinal axis  13 . In one preferred embodiment, five bore teeth each with a height of 0.030 inches are located on the surface of bore  30  adjacent to neck  22  with the centermost tooth bisected by longitudinal axis  13 . U.S. Pat. No. 5,842,391 to Chaconas discloses examples of pawless wrenches that have the head bore teeth located at different positions within the bore and is incorporated by reference herein in its entirety. While the present invention may also include embodiments having only a single bore tooth, a plurality of bore teeth increases the torque loading of the wrench. In order to withstand the sheer forces associated with torquing a workpiece, the height of the bore tooth is preferably 75% of the width of the bore tooth. 
         [0031]    Referring to  FIGS. 4 and 5 , rotor  16  has a first portion  52  defined over a third radius R 3  and a second portion  56  defined over a fourth radius R 4  that is larger than radius R 3 . First portion  52  has rotor teeth  54  that are axially aligned with the rotor&#39;s centerline on the rotor&#39;s outer circumferential surface that are configured to interengage with bore teeth  34 . Each rotor tooth has a first surface  55  that extends generally parallel to the plane that bisect the rotor tooth and intersects the center of rotor  16 . Each rotor tooth as has a second surface  57  that extends generally parallel to the plane that bisect the rotor tooth and intersects the center of rotor  16  such that first surface  55  and second surface  57  are substantially parallel. In some embodiments, first surface  55  and second surface  57  are angled slightly inward such that the base of the tooth is wider than the tip of the tooth thereby creating a trapezoid-shaped tooth. The shape and size of rotor teeth  54  closely resemble the shape and size of bore teeth  34  such that bore teeth  34  interengage with rotor teeth  54 , as shown in  FIG. 7 . 
         [0032]    First portion  52  further defines a first cavity  58  therein that is configured to engage a workpiece. In the embodiment shown in  FIG. 4 , first cavity  58  has a hexagonally shaped cross-section and is formed from a series of substantially planar surfaces  60  separated by curved portions  62 , which prevent the rounding of workpiece corners during torquing. A wall  64  is included between first cavity  58  and the first portion outer circumference and is sized to maintain proper strength qualities for a desired application. Referring specifically to  FIG. 5 , a lip  66  is formed about the outer edge of first portion  52  adjacent an edge  92  of rotor teeth  54 . A tapered portion  68  facilitates positioning of first cavity  58  on a workpiece (not shown). In other embodiments, first cavity  58  can be configured to receive an open socket or other tool for performing a desired function. Still further embodiments are contemplated in which rotor  16  does not have a central opening, but instead carries a tang for receipt in a conventional socket. 
         [0033]    Second portion  56  further defines a second cavity  70  that also is hexagonally shaped and formed from a series of substantially planar surfaces  72  separated by curved portions  74 . While first cavity  58  and second cavity  70  could be configured to engage different-sized workpieces, in the embodiment shown in the figures, the cavities are sized to engage a similarly-sized workpiece. 
         [0034]    Second portion  56  includes a flange  76  having a frictional outer edge surface  78  ( FIG. 4 ). The flange may be formed from any number of materials, and may be a ring press-fitted to the outer circumference of second portion  56  or may be integrally formed with the rotor. Frictional outer edge surface  78  in the Figures is shown as a knurled surface designed to facilitate a user&#39;s rotation of rotor  16  by hand. Other suitable frictional surfaces, such as an elastomeric surface, could be used instead of the knurled surface. Flange  76  is also referred to as a “speed ring” because it allows a user to quickly spin rotor  16  without moving handle  12 . Use of the speed ring is particularly advantageous once a threaded workpiece has been broken loose and only a low amount of torque is necessary to rotate the workpiece, such as during the removal of an oil drain plug. The same would be true when the workpiece is initially threaded during installation of the workpiece. Thus, while the amount of torque the user is able to impart to a workpiece is reduced when using flange  76 , a higher number of rotations of rotor  16  may be accomplished in a shorter time. Second portion  56  also includes a groove  80  ( FIG. 4 ) that receives an O-ring  82 . O-ring  82  is preferably formed of an elastomer or other polymeric material and may be made in different colors to assist in the identification of different size wrenches. 
         [0035]    Still referring to  FIG. 5 , rotor  16  includes a web  84  between first cavity  58  and second cavity  70 . A bore  88  formed through web  84  receives a magnet  86  that retains a workpiece, such as an oil drain plug, within one or both of the cavities. Magnet  86  may be of any suitable shape material, and in one embodiment, magnet  86  is generally cylindrical in shape, formed from rare earth material and is press-fitted into bore  88 . It should be understood that magnet  86  may be formed from two magnets one mounted in first cavity  58  and the other mounted in second cavity  70  proximate web  84 , and may also be formed from other suitable materials, such as ferrite. 
         [0036]    Referring to  FIG. 6 , rotor  16  is partially received within head bore  30 . Bore radii R 1  and R 2  ( FIG. 3 ) are substantially equal to radius R 3 . Since first arc center  42  and second arc center  43  are offset by distance A, rotor  16  can translate along longitudinal axis  13  by a distance substantially equal to distance A. Distance A is greater than the tooth height of rotor teeth  54  and bore teeth  34 . Thus, when the rotor is translated away from the bore teeth there is sufficient free play between rotor  16  and inner circumferential surface  32  to allow the rotor teeth  54  to index over bore teeth  34  while not under torque loading. 
         [0037]    Referring again to  FIG. 5 , a circular washer  90 , having a width W, abuts rotor teeth end  92  and surrounds lip  66  ( FIG. 6 ). Washer width W is selected so that the washer substantially seals the interior of bore  30  from the outside, thereby preventing debris from interfering with the operation of the rotor and bore teeth. In the embodiment shown in  FIGS. 2 and 6 , the outer diameter of washer  90  is approximately equal to second rotor portion radius R 4 . Once first portion  52  is inserted into head bore  30 , and washer  90  is fitted about lip  66 , a circular staking operation is performed upon lip  66  to secure washer  90  on rotor  16  and against bottom surface  28  so that the rotor is secured within head bore  30 . When the rotor is installed in the head bore, a shoulder  94  ( FIG. 4 and 5 ) abuts head top surface  26 . Since radius R 4  is larger than radius R 3 , rotor second portion  56  is sufficiently large to cover the opening created by head bore  30 . Otherwise, debris could enter between first portion  52  and head bore  30 , thereby negatively affecting the performance of the wrench. 
         [0038]    The operation of wrench  10  will now be described with reference to  FIGS. 7 and 8 . Referring first to  FIG. 7 , with rotor cavity  58  mounted on a workpiece, application of force to wrench  10  in the first direction  35  causes translation of rotor  16  relative to bore  30  along longitudinal axis  13 . This translation engages rotor teeth  54  with head bore teeth  34 . In this position, clockwise or counterclockwise rotation of handle  12  causes the rotor teeth  54  to contact bore teeth  34 . Thus, as the wrench is rotated clockwise or counterclockwise, the load applied by handle  12  will be distributed over the surface area of contact between the bore and rotor teeth, thereby imparting rotation to the workpiece in the clockwise or counterclockwise direction. Once a full swing of handle  12  is reached, the handle is rotated in the opposite direction so that rotor teeth  54  pass over bore teeth  34 , as described below. 
         [0039]    Referring now to  FIG. 8 , generally cylindrical rotor  16  is shown in an indexing position wherein application of force to wrench  10  in the second direction  37  causes translation of rotor  16  relative to bore  30  along longitudinal axis  13  thereby disengaging rotor teeth  54  from bore teeth  34 . That is, as handle  12  is rotated in either a clockwise or counterclockwise, neither bore teeth surfaces  38  or  40  bear against rotor teeth surfaces  55  or  57  so that the rotor can index in the opposite direction to that which torque is being applied. This indexing effect allows the head to rotate with respect to the rotor. 
         [0040]    To loosen or tighten a workpiece (assuming the workpiece is right hand threaded), the user orients the wrench such that rotor cavity  58  ( FIG. 6 ) receives the workpiece. In this position, cavity  58  engages the workpiece and the user can apply force in first direction  35  to wrench  10 . Due to the oval shape of bore  30 , such application of force causes translation of rotor  16  within bore  30 . This translation is substantially similar to distance A. The translation of rotor  16  causes rotor teeth  54  to engage bore teeth  34 . The spacing between adjacent rotor teeth is larger than the spacing between adjacent bore teeth which serves to ease interengagement of rotor teeth  54  and bore teeth  34 . Additionally, the spacing helps to avoid binding of the rotor during operation. Once the rotor and bore teeth are interengaged, rotor teeth  54  and the bore teeth  34  remain in contact as rotational torque is applied to the workpiece in the clockwise or counterclockwise direction without the need for continuous application of force in first direction  35 . As a clockwise or counterclockwise direction force is applied to handle  12  that force is translated through bore teeth  34  to rotor  16  be way of rotor teeth  54 . If rotating handle  12  in a clockwise direction, side  38  ( FIG. 3 ) of each bore tooth applies force to the engaged rotor teeth. If rotating handle  12  in a counterclockwise direction, side  40  ( FIG. 40 ) of each bore tooth applies force to the engaged rotor teeth. This force applied to the engaged rotor teeth, and therefore upon rotor  16 , is then translated to the workpiece. Depending on the direction of rotation, the workpiece will rotate and either loosen or tighten. 
         [0041]    When force in direction  37  is applied to wrench  10 , translation of bore  30  will again occur. Such translation causes rotor teeth  54  to disengage from bore teeth  34 . In this disengaged position, the handle can rotate allowing the rotor teeth to index over the bore teeth such that the head rotates with respect to the rotor. Since rotor teeth  54  and bore teeth  34  are not interengaged, force will not be applied to the rotor or workpiece during indexing. Once the handle has been indexed about the rotor, force can again be applied in direction  35  to engage the rotor teeth with the bore teeth so that rotational force can be applied to the workpiece. 
         [0042]    Optionally, when the teeth are disengaged, the use of speed ring  76  can be aid the user in the operation of wrench  10 . While using wrench  10  to loosen a workpiece, once the user breaks the workpiece loose speed ring  76  can be gripped by hand and rotated counterclockwise to remove the workpiece without having to swing handle  12 . Alternatively, if using wrench  10  to tighten a workpiece, once a workpiece is engaged by the wrench, the user may grip speed ring  76  by hand and rotate clockwise to tighten the workpiece to a point in which additional force is needed. 
         [0043]    Referring to  FIG. 9 , a wrench  110  is shown constructed in accordance with another embodiment of the present invention. A handle  112  is integrally formed with a first head  114  and a second head  115 . First head  114  and second head  115  are integrally formed with handle  112  by a neck  122 . One skilled in the art will recognize that as an alternative to either first head  114  or second head  115 , a bore, or other means of storing the wrench, could be provided. Alternatively, first head  114  or second head  115  could define an open end wrench or other tool. The operation and construction of wrench  110  is substantially similar to the embodiments previously discussed, the primary difference is the use of a rotor  116  ( FIG. 10 ). In this embodiment, first head  114  and second head  115  each receive rotor  116 . 
         [0044]    Referring to  FIG. 10 , rotor  116  has a central cavity  158  that defines a twelve-point surface  120  for engaging a nut or other component to be torqued. It should be understood that cavity  158  may define any shaped opening such as a torx shape, square, hexagonal, etc. In other embodiments, central opening  158  can be configured to receive an open socket or other tool for performing a desired function. Still further embodiments are contemplated in which rotor  116  does not have a central opening, but instead carries a tang for receipt in a conventional socket. 
         [0045]    Referring to  FIG. 11 , a series of bore teeth  134  are formed on a portion of inner circumferential surface  132 . With reference to a first bore tooth  136 , each bore tooth has a first surface  138  and a second surface  140  that are substantially parallel to a plane that bisects first bore tooth  136  and intersects first arc center  142 . In one preferred embodiment, first surface  38  and second surface  140  are substantially symmetric about a longitudinal center axis of first square-shaped bore tooth  136 . In one preferred embodiment, bore teeth  134  each have a width of 0.041 inches with 0.066 inches of spacing between adjacent teeth. In some embodiments, first surface  138  and second surface  140  are symmetrical about a longitudinal center axis of the tooth yet angled slightly inward such that the base of the tooth is wider than the tip of the tooth thereby creating a trapezoid-shaped tooth. Bore teeth  134  are arranged sequentially on inner circumferential surface  132  from first tooth  136  to a last tooth  144 . These teeth are of substantially equal height and shape and positioned on bore  130  such that bore teeth  134  are symmetric about longitudinal axis  113 . 
         [0046]    Referring also to  FIGS. 12 and 13 , rotor  116  is defined over a second radius R 7 , and has rotor teeth  154  that are axially aligned with the rotor&#39;s centerline on the rotor&#39;s outer circumferential surface. Rotor teeth  154  are substantially similar to the rotor teeth described previously and are configured to interengage with bore teeth  134  ( FIG. 11 ). 
         [0047]    Wall  164 , between the root of teeth  154  and the inner diameter of rotor  116 , is sized to maintain proper strength qualities for a desired application. First lip  166  is formed about a first outer edge of rotor  116  adjacent an edge  192  of rotor teeth  154 . A second lip  167  is formed about a second outer edge of rotor  116  adjacent an edge  193  of rotor teeth  154 . Tapered portions  168  and  188  facilitate positioning of first cavity  158  on a workpiece (not shown). 
         [0048]    Referring to  FIGS. 11 and 13 , rotor  116  is received within head bore  130 . As with the previous embodiments, bore radii R 5  and R 6  are substantially equal to radius R 7 . Since center of first arc  142  and center of second arc  143  are offset by distance A thereby creating an oval, rotor  116  can translate along longitudinal axis  113  by a distance substantially similar to distance A. Thus, there is sufficient free play between rotor  116  and inner circumferential surface  132  to allow the rotor teeth  154  to index over bore teeth  134  while not interengaged. 
         [0049]    Referring now to  FIGS. 12 ,  13  and  14 , a first circular washer  190 , having a width W, abuts rotor teeth end  192  and surrounds lip  166 . A second circular washer  191 , having a width W, abuts rotor teeth end  193  and surrounds lip  167 . Washer width W is selected so that the washer substantially seals the interior of bore  130  from the outside, thereby preventing debris from interfering with the operation of the rotor and bore teeth. Once rotor  116  is inserted into head bore  130 , and washer  190  is fitted about lip  166 , a circular staking operation is performed upon lip  166  to secure washer  190  on rotor  116  and against top surface  126 . Similarly, once washer  191  is fitted about lip  167 , a circular staking operation is performed upon lip  167  to secure washer  191  on rotor  116  and bottom surface  128  so that the rotor is secured within head bore  130 . 
         [0050]    The operation of the wrench shown in  FIGS. 9-16  is the same as the described for the wrench in  FIGS. 1-8 . Therefore the discussion is not repeated herein. While one or more preferred embodiments of the invention have been described above, it should be understood that any and all equivalent realizations of the present invention are included within the scope and spirit thereof. The embodiments depicted are presented by way of example and are not intended as limitations upon the present invention. Thus, those of ordinary skill in this art should understand that the present invention is not limited to these embodiments since modifications can be made. Therefore, it is contemplated that any and all such embodiments are included in the present invention as may fall within the scope and spirit thereof.