Abstract:
Among other things, an open-ended wrench comprises a wrench head defining an opening to receive a work piece. The wrench head comprises a first jaw including at least a first surface to engage with a surface of the work piece, a second jaw including a first curved surface facing the opening, and a plate mounted on the second jaw and movable relative the second jaw. The plate comprises at least a second surface to engage with another surface of the work piece. The plate also comprises a second curved surface engaging the first curved surface and being slidable against the first curved surface.

Description:
TECHNICAL FIELD 
       [0001]    This description relates to an open-ended ratchet wrench. 
       BACKGROUND 
       [0002]    There are many occasions when it is desirable to apply a torque to a work piece (such as nuts, bolts, and in-line hydraulic fittings) in order to, for example, rotate the work piece with respect to a threaded member. Two well-known tools for rotating work pieces are ratchet wrenches and open-ended crescent wrenches. Ratchet wrenches are typically close-ended devices that completely encircle the work piece and are thus installed on the work piece from the top (or bottom, depending upon the orientation of the work piece). Open-ended wrenches can be installed from the side of the work piece. 
         [0003]    Open-ended wrenches are useful in small work spaces where there may only be sufficient room to install the wrench from the side. In some situations, confined work spaces may provide insufficient space to accommodate the ratchet mechanism of close-ended ratchet wrenches. Open-ended wrenches are also useful in tightening/loosening in-line fittings of hydraulic or fuels lines, which are configured to receive a wrench from the side. 
       SUMMARY 
       [0004]    In one aspect, the description features an open-ended wrench comprising a wrench head defining an opening to receive a work piece. The wrench head comprises a first jaw including at least a first surface to engage with a surface of the work piece, a second jaw including a first curved surface facing the opening, and a plate mounted on the second jaw and movable relative the second jaw. The plate comprises at least a second surface to engage with another surface of the work piece. The plate also comprises a second curved surface engaging the first curved surface and being slidable against the first curved surface. 
         [0005]    The opening is partially enclosed and there is an entrance between the first jaw and the plate to enable the work piece to be received. The first and the second curved surfaces have the same curvature. The second jaw further comprises a supporting member extending from the first curved surface towards the opening. The plate includes a proximal end and a distal end, and the plate comprises plate members that are separated by an open space at the proximal end and joined at the distal end. The supporting member of the second jaw is accommodated in the open space between the plate members of the plate. The supporting member comprises a slot and the wrench head further comprises a pin to be fastened to the plate members and to pass through the slot to attach the plate to the second jaw. The slot has a length that enables the pin to move within the slot. The slot is oriented so that the movement of the pin causes the second curved surface to slide against the first curved surface without disengaging the first and the second curved surfaces. The pin moves within the slot without contacting the supporting member. Each plate member includes a slot and the wrench head further comprises a pin to be fastened to the supporting member and to pass through the slots of the plate members. Each slot of the plate member has dimensions larger than the dimensions of the pin. The wrench head further comprises a spring having a first end attached to the wrench head and a second end to engage the plate. The first and the second surfaces are planar surfaces. The first jaw and the plate define a six-point design. The first and the second surfaces are corrugated. The first jaw and the plate define a twelve-point design. The first jaw is stationary relative to the second jaw. 
         [0006]    In another aspect, the description features a method of making an open-ended wrench. The method comprises providing a base for a wrench head, the base including a first jaw and a second jaw that partially enclose an opening, the second jaw including a first curved surface facing the opening; and mounting a plate onto the second jaw, the plate being movable relative to the second jaw. Mounting the plate comprises engaging a second curved surface of the plate with the first curved surface of the second jaw, the second curved surface slidable against the first curved surface. Mounting the plate can further comprise engaging a spring attached to the base with the plate. Mounting the plate can further comprise fastening a pin to the plate and passing the pin through a slot defined in the second jaw, the pin movable within the slot. 
         [0007]    Another aspect describes an apparatus comprising an open-ended wrench having an opening between a first jaw and a movable plate mounted on a second jaw and means for loading a work piece from an entrance between the first jaw and the movable plate into the opening. The movable plate is in a locked state and has a curved surface engaging and slidable against a curved surface of a second jaw. The curved surface of the movable plate slides against the curved surface of the second jaw to move the movable plate away from the locked state and increase a width of the entrance to load the work piece. After the work piece is loaded, the curved surface of the movable plate slides against the curved surface of the second jaw to allow the movable plate to return towards the locked state to grasp the work piece. 
         [0008]    In another aspect, the description features an apparatus comprising means for loading a work piece into an opening defined by a first jaw and a movable plate mounted on a second jaw of an open-ended wrench. The work piece has at least a first surface to engage a surface of the first jaw and a second surface to engage a surface of the movable plate. The movable plate has a curved surface engaging a curved surface of the second jaw. The apparatus also includes means for turning the loaded work piece in a driving direction to into a first position. The work piece and the movable plate remain stationary relative to the first and the second jaw. The apparatus also includes means for ratcheting the loaded work piece in a ratcheting direction. The work piece remains stationary relative to the first position and to the movable plate At least a portion of the surface of the first jaw disengages the first surface of the work piece and the curved surface of the movable plate slides against the curved surface of the second jaw. 
         [0009]    In another aspect, the description features an open-ended wrench comprising a first stationary jaw, a movable plate mounted on a second stationary jaw, a pin retaining the movable plate on the second stationary jaw, and means for transmitting forces from the movable plate to the second stationary jaw without having the force passing through the pin. Surfaces of the first stationary jaw and the movable plate partially surround an opening to receive a work piece in the open-ended wrench. 
         [0010]    The details of one or more examples are set forth in the accompanying drawings and the description below. Further features, aspects, and advantages will be apparent from the description, drawings, and the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0011]      FIGS. 1 ,  5 , and  6  are schematic top views of open-ended ratchet wrenches engaging a work piece. 
           [0012]      FIG. 2  is a perspective view of an open-ended ratchet wrench. 
           [0013]      FIG. 3A  is a perspective view of a portion of the open-ended ratchet wrench. 
           [0014]      FIG. 3B  is a perspective view of a movable plate. 
           [0015]      FIG. 3C  is a schematic back view of a movable plate. 
           [0016]      FIG. 4  is a schematic cross-sectional view of an open-ended wrench. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Referring to  FIG. 1 , an open-ended ratcheted wrench  1  includes an elongated handle  6  and a head  2  defining an opening  3 . A work piece  5  can be loaded, e.g., inserted, into the opening  3  along a direction y that is substantially in line with a longitudinal axis of the elongated handle  6 . Such a loading is sometimes called loading from the side. Examples of the work piece  5  can include, e.g., a head of a bolt, a nut, or an in-line fitting. When loaded, portions of one or more surfaces of the work piece  5  engage one or more work piece engaging surfaces, e.g., surfaces  13 ,  15 ,  17 , of the head  2 . A user (not shown) can turn, e.g., within the x-y plane, the handle  6  to apply forces or torque to the work piece  5  through the engaged surfaces  13 ,  15 ,  17 . The work piece  5  can turn around a center  19  (center of the work piece, or CW). The user can turn the handle  6  back (counterclockwise, in a resetting direction R) and forth (clockwise, in a driving direction D) continuously to turn the work piece  5  in the driving direction D, without unloading the work piece  5  from the opening  3 . The operational mechanism of the wrench  1  is further discussed with respect to  FIGS. 5 and 6 . 
         [0018]    Referring to  FIGS. 1 ,  2 , and  3 A- 3 C, the open-ended wrench  1  has its structure shown. The head  2  includes a pair of stationary jaws  4 ,  8  connected to the handle  6 . In some implementations, the stationary jaws  4 ,  8 , and the handle  6  are formed, e.g., machined, as an integral member, e.g., in a solid piece. The jaw  4  includes an inner work piece engaging surface  13  facing the opening  3 . The work piece engaging surface  13  is stationary relative to the wrench  1 . The jaw  8  supports a movable plate  14  that carries the movable work piece engaging surface  15 ,  17 . The work piece engaging surfaces  13 ,  15 ,  17  can be flat ( FIG. 1 ) or corrugated (FIGS.  2  and  3 A- 3 C). 
         [0019]    Referring to  FIG. 1 , when the work piece  5  is fully loaded in the opening  3  of the wrench  1 , the work piece engaging surfaces  13 ,  15 ,  17  engage the work piece  5  at an arc  51  (shown in dotted lines) of 270 degrees. The adjacent work piece engaging surfaces, e.g., surfaces  15 ,  17 , meet at corner  31  with an angle of 120 degrees. The wrench  1  in  FIG. 1  can accommodate hexagonal work piece  5  in a standard or 60 degree rotated position. Such an arrangement of the work piece engaging surfaces corresponds to a so-called six point design, because it will accommodate a six cornered hexagonal work piece. The work piece engaging surfaces  13 ,  15  have dimensions to engage opposing surfaces of the work piece  5  along the entire length of the surface. Surfaces  13 ,  15  are further divided into sections  13   a , 13   b  and  15   a ,  15   b . When the handle  6  is turned in a driving direction, torque is transmitted to work piece  5  through surface sections  13   a ,  15   a ,  17 . When handle  6  is turned in a ratcheting direction, work piece  5  remains stationary and pressure through surface sections  13   b ,  15   b  causes the moving plate  14  to partially disengage the surfaces  13 ,  15 . 
         [0020]    Referring to FIGS.  2  and  3 A- 3 C, the work piece engaging surface  13 , is cut with a notch  40  and surface  15  is cut with notch  42  to accommodate a work piece in a 30 degree rotated position. The wrench  1  thus is a so-called twelve point design because it can accommodate a hexagonal work piece in both a standard and a 30 degree rotated position. The work piece engaging surface  13  includes facets  13   a ,  13   b , separated by the notch  40 . The notch  40  includes facets (or surfaces)  40   a ,  40   b  meeting at the corner  31 . Each facet (or surface)  13   a ,  40   b ,  40   a ,  13   b  meets with an adjacent facet (or surface) at an angle of 120 degrees. Other angles can also be used. 
         [0021]    The work piece engaging surface  15  includes facets  15   a ,  15   b  separated by the notch  42 . The notch  42  includes facets (or surfaces)  42   a ,  42   b  meeting at the corner  31 . Each facet (or surface)  15   a ,  42   b , 42   a ,  15   b ,  17  meets with an adjacent facet (or surface) at an angle of 120 degrees. Other angles can also be used. When the wrench  1  captures the work piece  5  in a standard position and the handle  6  is turned in a driving direction, torque is applied to the work piece  5  through facets  13   a ,  15   a ,  17 . When the wrench  1  captures the work piece  5  in a standard position and the handle  6  is turned in a ratcheting direction, work piece  5  remains stationary and pressure to facets  13   b ,  15   b  causes the moving plate  14  to at least partially disengage the surfaces  13 ,  15 . The facet  17  is connected to an overhanging member  28  facing the opening  3 . 
         [0022]    When the wrench  1  captures work piece  5  in a 30 degree rotated position and the handle  6  is turned in a driving direction, torque is transmitted to the work piece  5  through facets  40   a ,  42   a . When wrench  1  captures the work piece  5  in a 30 degree rotated position and the handle  6  is turned in a ratcheting direction, work piece  5  remains stationary and pressure to surface  42   b  causes the moving plate  14  to at least partially disengage the surfaces  13 ,  15 . Referring to  FIGS. 2 ,  3 A, and  3 B, the movable plate  14  slides over a keel  16  of the jaw  8 . A curved outer surface  18  of the movable plate  14  engages a curved inner surface  27  of an outer member  23  of the jaw  8 . The curved outer surface  18  can slide along the inner surface  27  without disengagement. In some implementations, the outer member  23  of the jaw  8  can have the same thickness w as the jaw  4 . The keel  16  extends between the inner surface  27  of the jaw  8  and the jaw  4 , e.g., the overhanging member  29 . The keel  16  has a thickness t that is a fraction of, e.g., about ⅓, the thickness w of the outer member  23  and is located, for example, at the center of the width w. The inner surface  27  is separated into two portions by the keel  16 , each having a width of, e.g., about ⅓, thickness w of the outer member  23 . In some implementations, the jaw  8  is larger and more curved than the jaw  4 . The jaw  8  can also protrude from the handle  6  more than the jaw  4  does to accommodate the movable plate  14 . 
         [0023]    The movable plate  14  has a configuration that allows it to fit onto the jaw  8 . For example, the plate  14  can be arcuately shaped or kidney shaped, and elongated. The movable plate  14  includes a solid, distal end  33  and a slotted proximal end  35  ( FIGS. 3B and 3C ), and can have a thickness q that is substantially the same as the thickness w of the jaw  8 . The slotted proximal end  35  includes two plates  35   a  and  35   b  separated by a space  45 . 
         [0024]    When assembled onto the jaw  8 , each plate  35   a ,  35   b , of the movable plate  14  sits on either side of the keel  16  and the keel  16  is accommodated in the space  45 . Both the curved surface  18  of the movable plate  14  and the curved inner surface  27  of the jaw  8  have the same curvature and are parts of a curved surface (or arc) that is centered about a center  39  of the movable plate  14  (CMP  39 ). The CMP  39  is offset from the center of the engaged work piece (CW 19 ) ( FIG. 1 ). When the movable plate  14  moves, surface  18  slides along the curved inner surface  27  and the two surfaces  18 ,  27  remain engaged. The keel  16  provides strength to the jaw  8  and prevents the movable plate  14  from shifting away from the jaw  4  during loading and operation of the work piece  5 . The CMP  39  is offset from the CW  19  so that moveable plate  14  moves down towards handle  6  and away from CW  19  during ratcheting. 
         [0025]    In addition to the work piece engaging surface  15 , the movable plate  14  includes a cusp-shaped projection  28  near its distal end that provides the work piece engaging surface  17 . The surface  17  extends at an angle of 120 degrees relative to they axis towards the opening  3 . The projection  28  is short so as not to protrude excessively into the opening  3 . The moveability of the plate  14  and the small size of projection  28  allow the wrench  1  to load the work piece  5  from the side. The additional engaging surface  17  provided by the projection  28  allows the wrench  1  to engage the work piece  5  well. For example, if the work piece  5  is made of a soft material, e.g., brass or aluminum, it is desirable to capture as many surfaces of the work piece  5  as possible. 
         [0026]    The movable plate  14  is secured to the jaw  8  using a pin  10  ( FIG. 1 ,  FIGS. 3A-3C ) that passes though an arcuate-shaped slot  12  in keel  16  and openings  37   a ,  37   b  in the plates  35   a ,  35   b  of the movable plate  14 . The pin  10  can be secured to the movable plate through the openings  37   a ,  37   b  so that the movement of the pin  10  results in the movement of the movable plate  14 . The arcuate-shaped slot  12  has an upper curved surface  12   a  and a lower curved surface  12   b . Both curved surfaces  12   a ,  12   b  are co-centered with the curved surfaces  18 ,  27  at the CMP  39 . The slot  12  is larger than the pin  10  which can therefore move between the curves  12   a ,  12   b  from one proximal end  12   c  to a distal end  12   d  of the slot  12 , e.g., without contacting any surface of the slot  12 . The movable plate  14  can be directed to move around the CMP  39  by the movement of the pin  10 . 
         [0027]    The work piece engaging surfaces of the jaw  4  and the moving plate  14  are laterally spaced from each other by a suitable distance to define the central opening space  3  for receiving the work piece  5 . The space provided between the jaw  4  and the movable plate  14  can allow the work piece  5  to rotate with respect to the stationary jaws  4 ,  8  during ratcheting while remaining confined between the jaws  4 ,  8  (further discussed below). The wrench  1  does not have to be withdrawn from work piece  5  to rotate around the CW  19  of the work piece  5  during the ratcheting action. 
         [0028]    Referring to  FIG. 4 , a spring  24 , e.g., a coil spring, is positioned in the base of the wrench head  2  at the distal end of the handle  6 . One end  41  of the spring  24  is captured within a drilled hole  26  in the wrench head  2  and retained by a plug  32 . The other end  43  of the spring  24  engages the pin  10  and exerts a force F on the pin  10  to push the movable plate  14  towards the opening  3 . Spring  24  extends into the slot  12  and engages the portion of the pin  10  that is exposed in the open space  45  between the plates  35   a ,  35   b  ( FIG. 3C ). The plates  35   a  and  35   b  can be shaped and sized, e.g., elongated, to cover the slot  12 , to prevent disengagement of the spring  24  and the pin  10 , and to protect the spring  24  from dirt or debris. 
         [0029]    When no other external forces (other than forces existed in the wrench  1 ) are applied to the movable plate  14 , the spring force F pushes the pin  10  to rest at the distal end  12   d  of the slot  12 . The wrench  1  is in a fully locked position without engaging the work piece  5 . When the work piece  5  is held between the jaw  4  and the moving plate  14 , the pin  10  is pushed away from the distal end  12   d  of the slot  12 . In some implementations, the dimensions of the slot  12  and the properties of the spring  24 , e.g., the spring constant, are selected such that during the operation on the work piece  5 , the pin  10  does not substantially contact any surface  12   a - 12   d  of the slot  12 . No substantial torque resulting from moving or turning the work piece  5  is transferred through the pin  10  to the jaws  4 ,  8 . The pin  10  is used to retain the movable plate  14  and prevent it from falling out of head  2  of the wrench  1 . Substantially all forces and torque are transferred through the engaged surface  18  of the movable plate  14  and the surface  27  of the jaw  8 . The pin  10  is manufactured and used in the wrench  1  to endure prolonged wear. 
         [0030]    The work piece  5  can be loaded by sliding the wrench  1  onto the work piece  5  from the side. Initially, an end  45  of the work piece  5  has a width S that is larger than the opening P of head  2 . The user can force the work piece  5  to move forward towards the opening  3  by pushing the movable plate  14  against the spring force F. For example, the moving plate  14  and the pin  10  can be pushed downwards around the CMP  39  to make room for the work piece  5  to enter the space  3 . The spring  24  then pushes against the pin  10  and the movable plate  14  returns to the locked state to grasp the loaded work piece  5 . 
         [0031]    Referring to  FIGS. 5 and 6 , the driving ( FIG. 5 ) and ratcheting ( FIG. 6 ) operations of the wrench  1  are shown. The user can drive the work piece  5  by continuously turning the wrench handle  6  alternately in the driving direction D (clockwise,  FIG. 5 ) and the ratcheting direction R (counterclockwise,  FIG. 6 ) without withdrawing the wrench  1  from the work piece  5 . During the turn in the driving direction D, the work piece  5  turns and the movable plate  14  remains stationary relative to the stationary jaws  4 ,  8 . During the turn in the ratcheting direction R, the work piece  5  is stationary and the movable plate  14  slides towards the wrench handle  6 . 
         [0032]    Referring to  FIG. 5 , the work piece  5  is loaded in the opening  3  of the wrench  1 . When the user turns the wrench  1  in the driving direction D (clockwise), the stationary jaws  4 ,  8  receive a torque from the user&#39;s operation to rotate in the driving direction D. The jaw  4  transfers the torque directly to the work piece  5  through the engaged work piece engaging surface  13   a  and the surfaces of the work piece  5  to rotate the work piece in the driving direction D. On the opposite side of the jaw  4 , the jaw  8  transfers rotating torque through the surface  27  to the surface  18  of the moving plate  14 . The work piece engaging surfaces  15   a ,  17  of the movable plate  14  then transfer a torque onto the work piece  5  to rotate the work piece in the driving direction D. The turning of the wrench  1  urges the movable plate  14  to move with respect to the stationary jaws  4 ,  8  in a direction opposite to the direction D. This urged motion is prevented by the engagement of the surface  18  against the surface  27  of the jaw  8 . The movable plate  14  remains in the locked state and is stationary with respect to the jaws  4 ,  8 . The torques transferred from the jaw  4  and the movable plate  14  turns the work piece  5  in the driving direction D. 
         [0033]    In the 12 point wrench shown in  FIGS. 3 and 5 , when the work piece  5  is in a 30 degree rotated position, torque is transferred to the work piece  5  through the surface  40   a  of jaw  4  and  42   a  of moving plate  14 . 
         [0034]    Referring to  FIG. 6 , the wrench  1  is rotated in a ratcheting direction R (counterclockwise). The surfaces of the work piece  5  exerts a force on the engaged surface  15   b  of the movable plate  14 . The force pushes the movable plate  14  against the spring  24  ( FIG. 4 ). The pin  10  slides downwards towards the proximal end  12   c  of the slot  12  and the plate  14  slides downwards along the surface  27  of the jaw  8 . The space  3  between the stationary jaw  4  and the movable plate  14  increases, which allows the wrench  1  to ratchet around the work piece  5 . 
         [0035]    In the 12 point configuration with the work piece  5  in a 30 degree rotated position, the surface of the work piece  5  exerts forces to the movable plate  14  through the surface  42   b  when the wrench  1  is rotated in a ratcheting position. 
         [0036]    When the handle  6  is first rotated in the ratcheting direction R, the pin  10  moves through slot  12  towards the proximal end  12   c , and the surface  18  slides against the surface  27  of the jaw  8 . The movable plate  14  moves from the locked state ( FIG. 5 ) to an unlocked state. Therefore, as the handle  6  is rotated in the ratcheting direction R, the movable plate  14  rotates spirally with respect to the stationary jaws  4 ,  8 . The spiraling motion of the movable plate  14  is constrained by the movement of the pin  10  and the surface  18  against the surface  27 . 
         [0037]    The location of the CMP  39  and the orientation of the slot  12  and the surfaces  18 ,  27  are chosen so that the movable plate  14  can move downwards and outwards relative to the work piece  5 . The wrench  1  can rotate around the work piece  5  during the ratcheting operation and yet still have sufficient clearance, so that the corners of work piece  5  do not bind against the work piece engaging surfaces  13 ,  15 . The surfaces  13 ,  15 ,  17  of the movable plate  14  and the jaw  4  slide over the surfaces of the work piece  5 , allowing the work piece to remain stationary. 
         [0038]    In the six-point design shown in  FIG. 1 , approximately 60 degrees of handle rotation is required to ratchet the jaw  4  and the movable plate  14  around one corner  49  of the hexagonal work piece  5 . As each corner of the work piece  5  passes across the flat surface  15  into an adjacent cusp  31 , the spring force on the movable plate  14  from the spring  24  causes the movable plate  14  to return to the position shown in  FIG. 5 . In the twelve-point design shown in other figures, only 30 degrees of rotation is required before corners of the work piece  5  have moved into an adjacent cusp  31  on the jaw  4  and/or on the moving plate  14 . 
         [0039]    The driving and ratcheting directions R and D can be reversed by turning the wrench about they axis by 180 degrees, so that in a top view, the jaw  4  is on the right side of the work piece  5 . In this arrangement, the driving direction D is counterclockwise and the ratcheting direction R is clockwise. 
         [0040]    Components of the wrench  1  can be readily manufactured and assembled. Materials suitable for use in the components of the wrench  1  include tool steel, hardened steel, or others. Different components, e.g., the stationary jaw  4 ,  8 , and the movable plate  14  can be made of the same or different material(s). The wrench  1  can be scaled up or down in size and enlarged or miniaturized with respect to standard and metric sized open-ended wrenches. In some implementations, the stationary jaws of the wrench can receive movable plates having different sizes to provide openings  3  with different sizes. A movable plate with a suitable size can be selected and assembled with the jaws of the wrench to accommodate work pieces having a particular size and shape without use a different wrench. 
         [0041]    Still other embodiments are within the scope of the following claims. 
         [0042]    For example, the wrench may have an elongated plate with more or fewer work piece engaging surfaces. The movable plate and the stationary jaws can have other shapes. The slot and pin may be reversed, so that the pin is defined in the keel and the slot is defined in the proximal end of movable plate. 
         [0043]    The wrench handle does not have to be in line with or in the same plane as the jaws. For example, the handle may be offset relative to the jaws by an acute angle in the plane of the jaws, out of the plane of the jaws, or both. The wrench handle and the jaws may be made of separate pieces and connected by a wrist pin. The adjustment of the pin may allow pivoting of the handle upwards or downwards with respect to the plane of the wrench head. The wrench handle may be curved or may have other shapes. 
         [0044]    The wrench may have a shortened handle embedded with a square hole to accommodate a torque wrench, e.g., which is known as a crowfoot design. 
         [0045]    The wrench may have a wrench head, for example, the wrench head  2 , on both ends of the wrench handle. Each wrench head can have a first and a second jaws and a movable plate mounted on the second jaw. The first jaw and the movable plate include work piece engaging surfaces that define an opening to receive work pieces. The wrench head on one end of the wrench handle can include an opening having a different size and/or shape than an opening included in the wrench head on the other end of the wrench handle. The two different openings can receive work pieces having different sizes or shapes. 
         [0046]    Other than a coil spring, a flat spring, a flexure, or other types of springs that can engage with the pin and control the movement of the movable plate. The spring may be fixed to the wrench handle or the wrench head in other ways. 
         [0047]    Other open-ended ratchet wrenches are described in U.S. Pat. Nos. 5,456,143, 5,829,327, 6,223,630, and 7,024,971, the entire contents of which are incorporated herein by reference. One or more components of the wrench described in these U.S. patents may be combined with, or incorporated into, the wrench described herein. 
         [0048]    A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made. 
         [0049]    Other embodiments not specifically described herein are also within the scope of the following claims.