Patent Publication Number: US-2003221521-A1

Title: Ratchet tool having flat head

Description:
FIELD OF THE INVENTION  
       [0001] The present invention relates to a ratchet tool that has no protrusion extending from the head which is able to reach a narrow and deep position. The direction of rotation is changed by pivoting the handle.  
       BACKGROUND OF THE INVENTION  
       [0002] A conventional ratchet tool generally includes a head with a handle extending therefrom and a driving member rotatably received in a hole defined in the head. A recess is defined in an inside of the hole and a bead and a spring are respectively received in the recess so that the bead is engaged with a pawl which has teeth to be engaged with the teeth defined in an outer periphery of the driving member in the head. A control member is connected to the pawl and extends from a surface of the head such that the user may operate the control member to change the position that the pawl is engaged with the driving member and the direction of rotation of the ratchet tool can be changed to output a torque to tighten or loosen an object such as a nut or a bolt. However, the control member extending from the head increases the thickness of the head and the head can not be inserted in a narrow area to reach the object. Furthermore, to drill a recess in the inside of the hole requires special tool which increases the manufacturing cost of the ratchet tool.  
       [0003] The present invention intends to provide a ratchet tool that chooses the direction of rotation by pivoting the handle.  
       SUMMARY OF THE INVENTION  
       [0004] In accordance with one aspect of the present invention, there is provided a ratchet tool which comprises a head having a hole for a driving member being rotatably received therein and an open end. A first recess is defined in a surface in which the hole is defined and a first spring and a first bead are received in the first recess. A cover plate is mounted to the head and a second recess is defined in an underside thereof. A second spring and a second bead are received in the second recess.  
       [0005] A handle has an end pivotably received in the open end of the head and located between the cover plate and the head. Two protrusions extend from two opposite sides of the handle and are respectively engaged with the first bead and the second bead. A pawl is connected to the end of the handle and has two groups of engaging teeth which are engaged with teeth of the driving member.  
       [0006] The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0007]FIG. 1 is an exploded view to show the ratchet tool of the present invention;  
     [0008]FIG. 2 shows the handle is pivoted to the left and the driving member is rotated with the tool clockwise;  
     [0009]FIG. 3 shows the handle is pivoted to the middle position which allows the head to be rotated counter clockwise while the driving member is remained still;  
     [0010]FIG. 4 shows the flexible plate is moved from a tip to a root of one of the teeth in the driving member when the handle is located at the middle position;  
     [0011]FIG. 5 shows that the handle is pivoted to the right and the driving member is rotated with the tool when the tool is rotated counter clockwise;  
     [0012]FIG. 6 shows the position relationship between the protrusions and the two beads when the handle is in the position as shown in FIG. 2;  
     [0013]FIG. 7 shows the position relationship between the protrusions and the two beads when the handle is rotated counter clockwise;  
     [0014]FIG. 8 shows the position relationship between the protrusions and the two beads when the handle is in the middle position, and  
     [0015]FIG. 9 is an exploded view to show that the pawl and the handle are made to be a one-piece member. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0016] Referring to FIGS. 1, 2 and  6 , the ratchet tool of the present invention comprises a head  1  having a hole  111  defined therethrough and an open end in which an end of a handle  5  is to be received. A first recess  116  is defined in a surface  11  in which the hole  111  is defined and a first spring  71  and a first bead  72  are received in the first recess  116 . A U-shaped stepped surface  113  extends from the surface  11  in which the hole  111  is defined and has two threaded hole  112  so that a cover plate  2  is fixed on the stepped surface  113  by bolts  80  which extend through two holes  21  in the cover plate  2  and are threadedly engaged with the two threaded holes  112 .  
     [0017] A driving member  3  is rotatably engaged with the hole  111  and has teeth  32  defined in an outer periphery of the driving member  3 . A polygonal hoe  31  is defined through the driving member  3  so as to be mounted to an object with polygonal head. An end of the driving member  3  is received in the hole  111  of the head  1  and the other end of the driving member  3  is engaged with a hole  22  in the cover plate  2 . A retaining ring  81  is mounted to the end of the driving member  3  extending through the hole  22  in the cover plate  2  and engaged in a groove  114  defined in an inside of the head  11 . A second recess  24  is defined in an underside of the cover plate  2  and a second spring  71 ′ and a second bead  72 ′ are received in the second recess  24 .  
     [0018] The end of the handle  5  is pivotably received in the open end of the head  1  and located between the cover plate  2  and the head  1  by extending a pin  82  through a hole  23  in the cover plate  2 , a hole  52  in the handle  5  and a hole  115  defined in the surface  11  of the head  1 . It is to be noted that the inner diameter of the hole  52  allows the pin  82  to be free rotated in the hole  52 , and a width of the open end of the head  1  is wider than a width of the end of the handle  5 . Two protrusions  53  extend from two opposite sides of the handle  5  and are respectively engaged with the first bead  72  and the second bead  72 ′. A recess  54  is defined in the end inserted in the open end of the head  1 .  
     [0019] A pawl  4  has a convex  43  extending from a first end of the pawl  4  and the convex  43  is engaged with the recess  54  of the handle  5 . Two groups of engaging teeth  41 ,  42  respectively extend from two ends of a second end of the pawl  4 . One of the two groups of engaging teeth  41 ,  42  is engaged with the teeth  32  of the driving member  3 . A flexible plate  6  is inserted in a slit  6  in an intermediate portion of the second end of the pawl  4  and engaged with the teeth  32  in the outer periphery of the driving member  3 .  
     [0020] When the handle  5  is positioned at the left position as shown in FIG. 2, the two sides of the end of the handle  5  contact the insides of the open end of the head  1  at “A” and “B”, and only the engaging teeth  41  are engaged with the teeth  32  of the driving member  3 . The driving member  3  is driven by the engagement of the engaging teeth  41  and the teeth  32  of the driving member  3  and rotated with the rotation of the handle  5  clockwise to output a torque to tighten or loosen an object.  
     [0021] Referring to FIGS. 3, 4,  7  and  8 , when rotating the handle  5  counter clockwise to a middle position, the engaging teeth  41  are disengaged from the teeth  32  of the driving member  3  which is not rotated when the tool is rotated counter clockwise. It is to be noted that the flexible plate  6  is moved from a root of one of the teeth  32  of the driving member  3  to a tip of the tooth  32  and then moves over the tooth  32  and drops to a root of the adjacent tooth  32  of the driving member  3  again. This generates sound of “click, click” when rotating the tool counter clockwise.  
     [0022] Referring to FIG. 5, when changing the direction of rotation of the tool, the user holds the head  1  and pivots the handle  5  to the right (counter clockwise) to force the protrusions  53  move over the two beads  72 ,  72 ′ and the two sides of the end of the handle  5  contact against the insides of the open end of the head  1  at positions “C” and “D”. The pawl  4  is also pivoted and the engaging teeth  42  are engaged with the teeth of the driving member  3 . The driving member  3  is co-rotated with the rotation of the tool in counter clockwise. The head  1  has no protrusion extending from a top or the bottom so that the thickness of the head  1  is slim and is able to reach an object located in a deep and narrow area.  
     [0023]FIG. 9 shows that the pawl and the handle are made to be a one-piece member.  
     [0024] While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.