Patent Publication Number: US-6220123-B1

Title: Structure of a ratchet wrench

Description:
BACKGROUND OF THE INVENTION 
     a) Technical Field of the Invention 
     The present invention relates to a wrench structure, and in particular, to a ratchet wrench capable of providing high torque movement. 
     b) Description of the Prior Art 
     As shown in FIG. 1, a common conventional wrench  10  has a plurality of engaging notches  11  formed as one unit with the wrench  10  and the notches  11  moves together with the wrench  10  to rotate a nut  12 . When the wrench  10  is rotated to a certain degree, as a result of restriction by object around the wrench  10 , the wrench  10  has to be lifted up and placed at the original position and then repeat the process in order to rotate the nut  12 . As a result of repeating engagement and disengagement of the wrench  10  with the nut  12 , the notch  11  of the wench  10  is often dislocated in the process of tightening or loosening of the nut  12 . 
     FIG. 2 is another prior art wrench  10  having a bent structure to provide convenient holding of the handle of the wrench  10  by a user. However, this type of wrench  10  has the drawback as that of FIG.  1  and the wrench  10  is often dislocated from the nut  12 . Besides, the process of tightening and loosening of nut  12  by using this wrench  10  is slow. 
     FIGS. 3 and 4 show another types of wrench  20  having a head portion being provided with a circular opening  201  to contain a ratchet wheel  21 . A cavity  202  is provided to the circular opening  201 , adjacent to the one lateral side of the rod body to contain a restrictive teeth structure  22  and a spring  23 . If the ratchet wheel  21  is to rotate clockwise, as the teeth of the ratchet wheel  21  is in engagement with that of the restrictive teeth structure  22 , and one side of the restrictive teeth structure  22  is restricted by the wall of the cavity  202 , thus, the ratchet wheel  21  cannot rotate clockwise, but the wrench  20  can rotate clockwise to drive the ratchet wheel  21  to rotate the nuts. If the ratchet wheel  21  rotates counterclockwise, as the teeth of the ratchet wheel  21  is in engagement with that of the restrictive teeth structure  22 , and one side of the restrictive teeth structure  22  is restricted by the spring  23  and the spring  23  is compressible, thus, ratchet wheel  21  can rotate freely in a counterclockwise direction, and t e eth-skidding is resulted by the teeth of the restrictive teeth structure  22  with that of the ratchet wheel. 
     The advantage of this wrench  20  is no repeating of engagement and disengagement of the nut  12  with the wrench  20 , and the operation of the wrench  20  is faster. However, if a reverse direction of the nut is required, the wrench  20  has to be changed to another face such that the ratchet wheel  21  can be rotated in a reverse direction. In view of the need of reversing the rotation of the wrench  20 , it cannot be made into the shape of the wrench  10  as shown in FIG. 2 to provide a bent angle so that the application of the wrench  20  is smooth. The drawback is also found in U.S. Pat. No. 5,636,557. 
     FIG. 5 is another ratchet wrench  30  having a ratchet wheel  31  provided with a restrictive teeth structure  32 . Two sides of the restrictive teeth structure  32  are provided with teeth for the engagement with that of the ratchet wheel  31 . The restrictive teeth structure  32  can rotate about a center to a certain degree. The restrictive teeth structure  32  causes the ratchet wheel  31  to produce a single direction rotation. If frequent reverse of direction of rotation is required, the restrictive teeth structure  32  rotates to a certain angle about the center, and at this instance, the teeth at one side of the restrictive teeth structure  32  can engage with the teeth of the ratchet wheel  31  and the restrictive teeth structure  32  causes the ratchet wheel  31  to produce a free rotation. Thus, the rotation of the restrictive teeth structure  32  is used to cause a change of rotation direction. Thus, the wrench having multiple angle shown FIG. 2 can be fabricated. However, this design has other drawback. The engagement of the restrictive teeth structure  32  and the ratchet wheel  31  is depend on a few teeth to provide rotation, if the torque is too great, the restrictive teeth  32  or the engaged teeth of the ratchet wheel  31  may be damaged. U.S. Pat. Nos. 5,884,538, 5,626,062 and 5,782,147 disclose this type of wrench. 
     U.S. Pat. Nos. 5,533,427 and 5,230,262 provides the advantages that shown in FIGS. 3 and 5. In U.S. Pat. No. 5,533,427, the ratchet wheel  40  of the disclosed wrench  10  is in engagement with the restrictive teeth structure  50  which can resist a larger torque. By using the reverse direction control  60 , 70 , the position of the engagement of the restrictive teeth structure  50  with that of the ratchet wheel  40  is changed so as to change the rotation direction of the ratchet wheel  40 . Unlike the wrench in FIG. 3, a reverse of the wrench is required. The wrench  10  can be made into a shape as shown in FIG. 2 to provide smooth use for the user. However, the drawback of such wrench  10  is that the head portion  20  is larger than that shown in FIG. 3 for the reason that the head portion  20  is used to contain the ratchet wheel  40 , a directional control  60  and the restrictive teeth structure  50 . The design principle of U.S. Pat. No. 5,230,262 is similar to that of U.S. Pat. No. 5,533,427. These two patents disclose wrenches with high torque. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to prove structure of a ratchet wrench, wherein the ratchet wrench provides a high torque driving. 
     Further features of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of a conventional wrench. 
     FIG. 2 is a schematic view of a further conventional wrench. 
     FIG. 3 is a schematic view of a further conventional wrench. 
     FIG. 4 is a perspective view of the conventional wrench of FIG.  3 . 
     FIG. 5 shows another schematic view of the conventional wrench. 
     FIG. 6 is a perspective exploded view of the structure of the ratchet wrench of the present invention. 
     FIG. 7 is a sectional view of the combination of the structure of the ratchet wrench of the present invention. 
     FIGS. 8 to  10  are schematic views illustrating the reverse displacement of the restrictive gear. 
     FIGS. 11 and 12 are perspective view of a second preferred embodiment of the present invention. 
     FIGS. 13 and 14 are perspective views of a third preferred embodiment of the present invention. 
     FIG. 15 is a schematic view of a forth preferred embodiment of the present invention. 
     FIG. 16 is a schematic view of a fifth preferred embodiment of the present invention. 
     FIG. 17 is a schematic view of a sixth preferred embodiment of the present invention. 
     FIG. 18 is a schematic view of the ratchet wrench which can combine with a socket in accordance with the present invention. 
     FIGS. 19 and 20 are schematic view showing the ratchet wheel of the present invention. 
     FIG. 21 is a perspective view of the ratchet wrench of the present invention. 
     FIG. 22 is a perspective view illustrating the unidirectional wrench head portion of the present invention. 
     FIG. 23 is a sectional view of the unidirectional movement in accordance with the present invention. 
     FIG. 24 is a perspective view of the ratchet wrench of the present invention. 
     FIGS. 25 and 26 are schematic view of the unidirectional movement of another preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION 
     Referring to FIGS. 6 and 7, there is shown a wrench head  41  having a circular opening  42  to contain a ratchet wheel  50 . A rotating disc  70  is used to cover the opening  42 . A cavity  43  is provided to the circular opening  42 , adjacent to the rod body of the wrench of the present invention to contain a restrictive teeth structure  60 . The bottom end of the cavity  43  is provided with a ball hole  44  to contain a spring  45  and a steel ball  46 , and the steel ball  46  urges against a protruded block  61  of the restrictive teeth structure  60 . 
     The top end of the ratchet teeth  51  of the ratchet wheel  50  is extended to an extension  52  having a relative small diameter, and the extension  52  is provided with a circular groove  53  for the mounting of a fastening ring  80 . 
     The restrictive teeth structure  60  includes a top ratchet teeth  62  and a bottom ratchet teeth  63 , the ratchet teeth  51  of the ratchet wheel  50  corresponds to the bottom ratchet teeth  63  to produce interlinked tightening or free rotation as a result of teeth dislocation. The top ratchet teeth  62  are interlinked with rotational ratchet teeth  73  of the rotating disc  70 . 
     The rotating disc  70  has an inner ring hole  71  which is provided with a circular groove  74  which is corresponding to the circular groove  53  of the ratchet wheel  50  for the mounting of the fastening ring  80 . The end face of the rotating disc  70  is provided with an embossed surface  72  and the bottom surface of the embossed surface  72  is provided with the rotational ratchet wheel  73  which is corresponding to the ratchet teeth  62  of the restrictive teeth structure  60  to drive the restrictive teeth structure  60 . 
     In accordance with the present invention, the pushing force of the spring  45  is used to push the steel ball  46  to urge the side of the protruded block  61  of the restrictive teeth structure  60  such that the restrictive teeth structure  60  holds the ratchet wheel  50  and leans against the wall surface of the cavity  43 . As shown in FIG. 8, the ratchet wheel  50  rotates in a clockwise direction and the restrictive teeth structure  60  is driven to drive accordingly. 
     As the restrictive teeth structure  60  is restricted by the wall of the cavity  43 , if the exerted force becomes larger and larger, the urging force also becomes larger to produce high torque rotational function. When the ratchet wheel  50  rotates in a counter-clockwise direction, the restrictive teeth structure  60  causes a t e eth-skidding phenomenon with the ratchet wrench and the ratchet wheel  50  rotates freely. The important characteristics of the present invention is to change the urging position of the restrictive teeth structure  60  and change the direction of free rotation of the ratchet wheel  50 . 
     Referring to FIGS. 9 and 10, the rotation of the rotating disc  70  drives the ratchet teeth  73  to rotate the ratchet teeth  62  of the restrictive teeth structure  60  and the protruded block  61  urges the steel ball  46 , and the spring  45  to move toward the ball hole  44  until the displacement of the protruded block  61 , and the steel ball  46  urges another side of the protruded block  61 , and the restrictive teeth structure  60  and the ratchet wheel  50  are urged to contact with the other wall of the cavity  43 . Thus, the direction of the restrictive teeth structure  60  is changed, and the ratchet wheel  50  can perform a tightening operation of another direction of rotation or another free rotating operation, and the direction of rotation is totally controlled by the direct driving of the rotating disc  70 . Accordingly, the present invention provides an operation of dual direction to a bolt  21 . In addition, the rod body  47  of the ratchet wrench can be bent to avoid the blockage of the bolt  21 . Thus, the present invention provides a rapid and convenient operation and a larger torque. 
     Referring to FIGS. 11 and 12, there is shown a second preferred embodiment for the directional control. In accordance with the preferred embodiment, the change of directional control of the ratchet teeth is changed by the control of the interlinking block  75 . The interlinking block  75  is provided at the lateral side of the rotating disc  70 , and the relative position of restrictive teeth structure  60  is provided with a recess  64 . The size of the recess  64  is larger than that of the interlinking block  75  in order to avoid the restrictive teeth structure  60  being blocked by the interlinking block  75  when the teeth-skidding phenomena is occurred. The interlinking block  75  riggers the restrictive teeth structure  60  to produce a displacement and the steel ball  46  urges the other side of the protruded block  61 . 
     Referring to FIGS. 13 and 14, there is shown a third preferred embodiment for the directional control. A depression  65  is provided to the restrictive teeth structure  60  and a slot  48  is provided to the cavity  43 . The extended rod  91  of the push button  90  passes through the cavity  43  and engages with the depression  65 . Thus, the push button  90  can directly interlink with the restrictive teeth structure  60  to cause a change of direction of rotation. This restrictive teeth structure  60  does not require the top ratchet teeth  62  and the bottom ratchet teeth  63 , and the rotating disc  70 . 
     Referring to FIG. 15, the rotating disc  70  is provided with an interlinked rod  76  which can be inserted into the depression  65 . When the rotating disc  70  rotates, the restrictive teeth structure  60  is driven to cause a change of direction of rotation. This restrictive teeth structure  60  design does not require the top  62  and the bottom ratchet teeth  63 . 
     Referring to FIG. 16, the rotating disc  70  is provided with an intercommunicated slot  77  having a size which can be inserted into the restrictive teeth structure  60 . When the rotating disc  70  rotates, the restrictive teeth structure  60  is driven to produce a change of direction of rotation. 
     Referring to FIG. 17, an insertion rod  68  can be inserted into the depression  65 , and the rotating disc  70  is provided with the intercommunicated slot  77 . When the insertion rod  68  moves, the insertion rod  68  moves to the other side of the intercommunicated slot  77 . Thus, the restrictive teeth structure  60  is driven to cause a change in the direction of rotation. 
     FIG. 18 shows the implementation of the present invention on a common ratchet wrench or in combination with the socket of the wrench to provide better effectiveness in application. 
     Referring to FIGS. 19 and 20, the steel ball  46  can be designed into a semi spherical shape to urge the restrictive teeth structure  60 , which also can achieve the change of direction of rotation. 
     In accordance with the present invention, if dual direction of rotation is not required, as shown in FIGS. 21,  22 ,  23  and  24 , the head portion of the ratchet wrench  40  is provided with a circular opening  42  to accommodate the ratchet wheel  50 . A cavity  43  is provided to the circular opening  41 , adjacent to the rod body of the wrench  10  contain the restrictive teeth structure  60 . The end terminal of the cavity  43  is provided with a ball hole  44  to contain the spring  45  and the steel ball  46 . The steel ball  46  urges the protruded block  61  of the restrictive teeth structure  60 . Thus, the steel ball  46 , the spring  45  and the restrictive teeth structure  60 , remain no change with respect to their positions. This preferred embodiment can provide a high torque unidirectional wrench. 
     In operation, the ratchet wheel  50  rotates clockwise to drive the restrictive teeth structure  60 . As the restrictive teeth structure  60  is restricted by the wall of the cavity  43 , if the exerted force becomes larger and larger, the urging force also becomes larger to produce high torque rotation function. When the ratchet wheel  50  rotates in a counter-clockwise direction, the protruded block  61  urges the steel ball  46 , and the steel ball  46  is urged by the spring  45 . As the spring  45  is compressible, the restrictive teeth  60  is pressed downward to the steel ball  46 , and the engagement of the restrictive teeth structure  60  and the ratchet wheel  50  is separated. That is, it is similar to the te e th-skidding phenomena and the ratchet wheel  50  rotates freely. Thus, the wrench is restricted to a single direction of rotation. 
     Referring to FIG. 25, a recess portion  66  is provided to the restrictive teeth structure  60  and the steel ball  46  urges the recess portion  66  of the restrictive teeth structure  60 . Thus the above function can also be attained. 
     Referring to FIG. 26, an urging end  67  is provided to the restrictive teeth structure  60  and the steel ball  46  urges the urging end  67 . Thus, the above function can also be achieved. While the invention has been disclosed and described with reference to preferred embodiments, it will apparent that variations and modifications may be made therein, and it is therefore intended in the following claims to cover each such variation and modification as falls within the true spirit scope of the invention.