Abstract:
A reversible ratchet wrench which uses a pawl that can be moved between a right position and a left position. The pawl is in continuous connection with a rotatable ratchet wheel. The ratchet wheel rotates freely in a clockwise direction when the pawl is in the right position and is fixed to the wrench body when in the left position. The ratchet wheel rotates freely in a counterclockwise direction when the pawl is in the left position and is fixed to the wrench body when in the right position. A drive plate is mounted on the panel and is connected to a mechanism which is manually moved to cause the pawl to move.

Description:
REFERENCE TO PRIOR APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 10/100,798, filed Mar. 18, 2002 entitled RATCHET WRENCH HAVING A SWITCH MECHANISM by the present inventors. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to ratchet wrenches and more particularly to a ratchet wrench that can reverse its direction of operation. 
     2. Description of the Related Art 
     Ratchet wrenches have long been known. A typical ratchet wrench comprises an elongated body which terminates in a head. The head usually includes either a socket or a socket pin. The socket and the socket pin is to be used to apply torque to a fastener to tighten and loosen that fastener. 
     Typically, ratchet wrenches utilize a small pawl which is pivoted to different positions relative to a ratchet wheel. With the pawl in one position, the ratchet wheel will permit the tool to be used to tighten a fastener in a clockwise direction and then slip if the tool is turned in a counterclockwise direction. With the pawl in the other position, the reverse is to occur. 
     One of the problems associated with prior art type of ratchet wrenches is that the mechanism that is used to produce the movement of the pawl is subject to wear, and after a period of time, the mechanism will actually wear out resulting in the ratchet wrench becoming in operative. It would be desirable to avoid this replacement of ratchet wrenches and permit the construction of a wrench which is not readily subject to being worn out. 
     SUMMARY OF THE INVENTION 
     The basic embodiment of the present invention takes the form of a ratchet wrench which is constructed of an elongated body which terminates at one end in a head. Within the head is formed a through opening. A ratchet mechanism is mounted on the head and connects with the through opening. The ratchet mechanism comprises a ratchet wheel mounted in the through opening. The ratchet wheel is rotatable in both a clockwise and counterclockwise direction. A torque applier is connected to the ratchet wheel. The torque applier is for applying a turning force to an exterior object. The ratchet wheel has a series of gear teeth. A pawl is mounted on the head with the pawl having an engagement means which is to engagingly connect with the series of gear teeth. The pawl is movable between a first position and a second position. With the pawl in the first position, the ratchet wheel is not rotatable in the clockwise direction and is rotatable only in the counterclockwise direction. With the pawl in the second position, the ratchet wheel is not rotatable in the counterclockwise direction but is rotatable in the clockwise direction. A drive plate is attached to the pawl and protrudes from the pawl. A switching mechanism is mounted on the head with the switching mechanism connecting with the drive plate. The switching mechanism is movable between a right position and a left position. Locating of the switching mechanism in the right position locates the pawl in the first position and locating of the switching mechanism in the left position locates the pawl in the second position. 
     A further embodiment of the present invention is where the basic embodiment is modified by the through opening formed within the ratchet wheel being of a non-circular configuration. 
     A further embodiment of the present invention is where the basic embodiment is modified by the torque applier comprising a socket pin. 
     A further embodiment of the present invention is where the basic embodiment is modified by the series of gear teeth being formed on the exterior surface of the ratchet wheel. 
     A further embodiment of the present invention is where the basic embodiment is modified by there being a connector engaging with the drive plate and the connector has an internal chamber with the drive plate extending into this internal chamber. 
     A further embodiment of the present invention is where the just previous embodiment is modified by there being formed a thin slit within the body of the connector and it is through this slit that the drive plate extends. 
     A further embodiment of the present invention is where the just previous embodiment is modified by the connector being formed of sheet material in the shape of a box. 
     A further embodiment of the present invention is where the basic embodiment is modified by the switching mechanism being manually operable. 
     A further embodiment of the present invention is where the basic embodiment is modified by the switching mechanism being defined as including a cavity with this cavity being adapted to receive the connector where the connector is movable with the switching mechanism. 
     A further embodiment of the present invention is where the basic embodiment is modified by the switching mechanism including a spring assembly which engages with the drive plate for causing movement of the switching mechanism between the right position and the left position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference is to be made to the accompanying drawings. It is to be understood that the present invention is not limited to the precise arrangement shown in the drawings. 
     FIG. 1 is an exploded (unassembled) isometric view of a first embodiment of ratchet wrench constructed in accordance with the present invention which uses a socket pin as a torque applier; 
     FIG. 2 is an isometric view of the head portion of the ratchet wrench of FIG. 1 in the assembled state; 
     FIG. 3 is a longitudinal cross-sectional view through the assembled ratchet wrench of FIG. 2; 
     FIG. 4 is a transverse cross-sectional view taken along line  4 - 4  of FIG. 3 showing the pawl engaging with the ratchet wheel in a first position; 
     FIG. 5 is a longitudinal cross-sectional view taken along line  5 - 5  of FIG. 3 which is similar to FIG. 4 but showing the pawl engaging with the ratchet wheel in a second position; 
     FIG. 6 is an isometric view of a second embodiment of switching mechanism that is utilized in conjunction with the ratchet wrench of the present invention; 
     FIG. 7 is a view similar to FIG. 4 but where the second embodiment of switching mechanism of FIG. 6 is used; 
     FIG. 8 is a view similar to FIG. 5 but with the second embodiment of switching mechanism of FIG. 6 being used; 
     FIG. 9 is a cross-sectional view similar to FIG. 4 but of a third embodiment of switching mechanism showing the switching mechanism in a first position; 
     FIG. 10 is a view similar to FIG. 9 but showing the second embodiment switching mechanism in a second position; and 
     FIG. 11 is an exploded isometric view of a fourth embodiment of this invention which is similar to FIG. 1 except that a socket is used as the torque applier. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring particularly to the drawings, there is shown in FIGS. 1-5 the first embodiment  20  of reversible ratchet wrench of this invention. The first embodiment  20  has an elongated body  22 . The body  22  is shown cylindrical. However, it is not necessary that the body  22  be cylindrical. For example, the body could be octagonal in shape. The body  22  could also be thin and flat with the lower end of the body being connected to some structure, such as an open end wrench. The upper end of the body  22  is connected to a head  24 . Formed within the head  24  is a through opening  26 . The through opening  26  is cylindrical. There is also a smaller in diameter through opening  28  formed within the head  24 . Internally within the head  24  the through opening  28  connects with the through opening  26  by a connecting passage  30 . Aligned with through opening  28  is an exit opening  29 . 
     A ratchet wheel  32  is mounted within the through opening  26  and is capable of rotational movement there within. The exterior surface of the ratchet wheel  32  forms a continuous series of gear teeth  34 . Fixedly mounted onto the ratchet wheel  32  is a torque applier commonly referred to as a socket pin  36 . The ratchet wheel  32  is mounted about a center shaft  38 . The socket pin  36  is to facilitate connection to an exterior structure that has a recess within which is to be located in a close conforming manner the socket pin  36 . The socket pin  36  is to be used to affect applying torque to the exterior structure by the engagement of the recess and the socket pin  36 . Such application of torque is well known. A common form of exterior structure what is commonly referred to as sockets that can be utilized to affect turning of a fastener. 
     Mounted within the connecting passage  30  is a pawl  40 . Pawl  40  has an upper arcuate surface that includes a plurality of gear teeth  42 . Fixedly mounted onto the back side of the pawl  40  is a drive plate  44 . Drive plate  44  is to extend through slit  46  of a connector  48 . Connector  48  is formed of sheet material which in transverse is of square configuration. Connector  48  will generally be no more than one-quarter to one-half inch in length. Connector  48  has an internal chamber  50 . Connector  48  is to be locatable within a cavity  52  of a switch housing  54 . The switch housing  54  has mounted therein a coil spring  56  which connects with a ball  58 . The switch housing  54  is mounted within through opening  28  and is securely held in position by means of a snap ring  60 . Snap ring  60  rides within groove  61  formed within smaller diametered cylindrical extension  55  which is integral to cylindrical body  57  of switch housing  54 . Extension  55  is located in exit opening  29  and extends exteriorly of head  24 . When in position, the ball  58  is capable of riding within indent  62  or indent  64 . If the ball  58  is located within indent  62 , the angular position of the switch housing  54  is such that the drive plate  44  is moved to the left, as is shown in FIG.  4 . In this position, the left edge of the pawl  40  abuts against wall surface  66  of the connecting passage  30 . If a turning torque is applied to the elongated body  22  in the direction of arrow  68  as is shown in FIG. 4, rotational movement of the ratchet wheel  32  is prevented. This is because the ratchet wheel  32  is locked to the pawl  40  which is pressed against the wall surface  66 . However, if the torque is applied in the direction of arrow  70 , the pawl  40  will turn with the elongated body  22  and slippage will occur between gear teeth  34  and  42 . This slippage produces a chattering action with is termed ratcheting. The pawl  40  will actually deflect slightly as it rides over the gear teeth  34 . This ratcheting action occurs because the right side of the pawl  40  is spaced from the wall surface  72  of the connecting passage  30 . 
     When the switch housing  54  is manually turned by handle  74  clockwise about twenty-five to thirty degrees to the position shown in FIG. 5, the drive plate  44  cants at a different angle which is permitted by the internal chamber  50  of the connector  48 . Also, the pawl  40  is relocated to the right, as is readily apparent when comparing FIG. 4 to FIG. 5 with the result that the pawl  40  will abut against wall surface  72  of the connecting passage  30 . In this position, the ball  58  now connects with indent  64 . When torque is applied to the elongated handle  22  in the direction of arrow  70 , the socket pin  36  is carried with the elongated body  22  with the result that a torque will be applied through the socket pin  36  to an exterior structure. This direction is counterclockwise. Movement of the elongated body in the clockwise position as represented by arrow  68  will result in the pawl  40  deflecting permitting slippage to occur between the gear teeth  34  and  42  because the pawl  40  is spaced from wall surface  66 . Again, there is a ratcheting movement created. 
     Although not shown, there could be an indent located between indent  62  and indent  64 , and when the ball  58  was located within that indent, the pawl  40  would be spaced from both wall surfaces  60  and  72 . This would permit a slipping ratcheting action to occur in both directions  68  and  70 . 
     Ratchet wheel  32  is held in position by a ring  76  which has an internal annular surface  77  which is mounted about annular shoulder  78  of the ratchet wheel  32 . The exterior surface of the ring  76  has an annular groove  80 . A snap ring  82  is to be mounted within the annular groove  80  with this snap ring  82  being also mounted within an annular groove  84  formed within the wall surface of the through opening  26 . The snap ring  82 , in cooperation with the ring  76 , functions to maintain the mounted position of the ratchet wheel  32  within the through opening  26 . 
     Referring particularly to the second embodiment  86  of this invention which shown in FIGS. 6-8 of the drawings, like numerals have been utilized to refer to like parts. However, instead of the drive plate  44  being mounted in conjunction with the connector  40 , cylindrical body  57  of the switch housing  54  is formed with a right angled cutout  88 . Within one wall surface of the right angle cutout  88  is located a small coil spring  90 . A similar coil spring  92  is mounted within the other wall surface of the right angle cutout  88 . Each of the coil springs  90  and  92  are capable of coming into contact with the drive plate  44 . Therefore, when the switch housing  54  is pivoted clockwise, as is shown in FIG. 7, the coil spring  90  will apply pressure against the drive plate  44  and move the pawl  40  against the wall surface  66 . This is the same position as was previously described in reference to FIG.  4 . If the switch housing  54  is now moved clockwise about twenty-five to thirty degrees, the coil spring  90  will be located spaced from the drive plate  44  and the coil spring  92  will then come into contact with the drive plate  44  and function to move the pawl  40  against wall surface  72 . This is the equivalent position to FIG.  5 . The advantage to the structure shown in FIGS. 6-8 is that the connector  48  has been eliminated and, in essence, the structural arrangement simplified. 
     Referring particularly to FIGS. 9 and 10 there is shown the third embodiment  94  of this invention. Again, like numerals have been utilized to refer to like parts. In the third embodiment  94 , the pivotable switch housing  54  has been eliminated and instead there is substituted a lineally movable slider  96  which is slidable within through hole  98 . The slider  96  includes a centrally located cavity  100 . The drive plate  44  is to be located within the cavity  100 . On one sidewall of the cavity  100  is located a coil spring  102 . A similar coil spring  104  is mounted on the opposite sidewall of the cavity  100 . The drive plate  44  is located between the coil springs  102  and  104 . 
     With the slider  96  being moved in the direction of arrow  106  within the through hole  98  of the head  24 , the coil spring  102  will apply pressure against the drive plate  44  and move the pawl  40  against wall surface  66 . This is again similar to FIG.  4 . Usage of the wrench of FIG. 9 will be in the same manner as the wrench was used in FIG.  4 . There is an indent  108  that is formed within the slider  96  that connects with a ball  110  which is spring biased outwardly by a coil spring  112 . The ball  110  will slip within the indent  108  which will tend to hold the slider  96  in this position and prevent accidental movement of the slider  96  when the wrench is being used when in the position of FIG.  9 . 
     When a manual force is applied in the direction of arrow  114  to the slider  96  to cause the slider to be moved to the right, as shown in FIG. 10 with coil spring  104  coming into contact with the drive plate  44  and cause the pawl  40  to be moved against wall surface  72 , the ball  100  would be disengaged from the indent  108  and will ride within indent  116  also formed within the slider  96 . This indent  116  will tend to retain the position of the slider  96  and prevent such from being accidentally moved so that the wrench can be used when in the position of FIG.  10 . 
     Referring particularly to FIG. 11, there is shown a fourth embodiment  118  of this invention, with again like numbers being used to refer to like parts. The only difference of the structure in FIG. 11 when compared to FIG. 1 is that the socket pin  36  is eliminated with a non-circular hole  120  being formed within the interior of the ratchet wheel  32 . Typically, the non-circular hole  120  will have a series of longitudinal grooves formed within the wall surface of the hole  120 . These longitudinal grooves can be defined as serrations with these serrations to connect with a hexagonal head of a fastener, which is not shown. Therefore, a turning movement can be applied to the fourth embodiment  118  which will result in appropriate turning of this hexagonal headed fastener, which is again not shown.