Patent Publication Number: US-2017361434-A1

Title: Ratchet wrench having positioning mechanism

Description:
TECHNICAL FIELD 
     The present invention relates to a ratchet wrench and, in particular, to a ratchet wrench having a positioning mechanism, whereby a rotary head is free to rotate by some certain angles and can be fastened quickly in a radial direction. 
     BACKGROUND 
     The ratchet wrench is a common hand tool for tightening operations. The ratchet wrench can be used flexibly and can move back and forth freely to tighten or loosen blots, nuts, or the likes, so it replaces a traditional wrench in many situations. 
     The ratchet wrench includes a head portion, a bar extending outwardly from the head portion, and a drive head disposed on the head portion. The drive head is drivingly associated with objects, e.g. nuts and bolts, by means of a variety of sleeves in different sizes. A user simply needs to hold the bar to swing it, and the objects can be loosened or tightened. However, the conventional ratchet wrench is often limited by a dead corner or a tiny space, and thereby the drive head of the ratchet wrench cannot fasten the objects smoothly. In solution, there is a ratchet wrench with a drive head rotatable with respect to the bar. However, the ratchet wrench with the rotatable drive head has a complicated structure for fixing the drive head, and its inconvenient operations cannot meet the market&#39;s expectations. 
     SUMMARY 
     It is an object of the present invention to provide a ratchet wrench with a positioning structure, whereby a rotary head can be fastened or released quickly by radially pushing a locking button. 
     Accordingly, the present invention provides a ratchet wrench with a positioning structure, comprising a drive bar, a rotary head and a locking button. The drive bar includes a fork arm, a fork opening formed at the fork arm, an axial hole communicating with the fork opening, and a radial hole communicating with the axial hole. The rotary head is pivotally connected to two ends of the fork arm, the rotary head includes a round housing, a ratchet apparatus disposed inside the round housing, a plurality of positioning recesses disposed on the round housing, and a pivot axis passing through the rotary head and the two ends of the fork arm, wherein the pivot axis is perpendicular to the radial hole. The locking button includes a locking rod disposed in the radial hole and a latch bar disposed in the axial hole. The locking rod is radially movable in association with movement of the latch bar, and the latch bar is engaged with or released from any of the positioning recesses. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will become more fully understood from the detailed description, and the drawings given herein below is for illustration only, and thus does not limit the disclosure, wherein: 
         FIG. 1  is a perspective view according to a first embodiment of the present invention; 
         FIG. 2  is a partial cross-sectional view according to the first embodiment of the present invention; 
         FIG. 3  is another perspective view according to the first embodiment of the present invention; 
         FIG. 4  is a partial cross-sectional view of  FIG. 3 ; 
         FIG. 5  is still another perspective view according to the first embodiment of the present invention; 
         FIG. 6  is a partial cross-sectional view of  FIG. 5 ; 
         FIG. 7  is a cross-sectional view according to a second embodiment of the present invention; 
         FIG. 8  is another cross-sectional view according to the second embodiment of the present invention; 
         FIG. 9  is a cross-sectional view according to a third embodiment of the present invention; and 
         FIG. 10  is another cross-sectional view according to the third embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Detailed descriptions and technical contents of the present invention are illustrated below in conjunction with the accompany drawings. However, it is to be understood that the descriptions and the accompany drawings disclosed herein are merely illustrative and exemplary and not intended to limit the scope of the present invention. 
     Referring to  FIGS. 1 to 4 , the present invention provides a ratchet wrench  100  having a positioning mechanism, comprising a drive bar  120 , a rotary head  200 , and a locking button  250 . In the present embodiment, the ratchet wrench  100  preferably includes an operation handle  110  for receiving the drive bar  120 . By quickly rotating the operation handle  110  when the ratchet wrench  100  is in an upright state or by moving back and forth the operation handle  110  when the ratchet wrench  100  is in a horizontal state, the rotary head  200  tightens or loosens an object (not illustrated). 
     The drive bar  120  includes a fork arm  130 , a fork opening  150  formed at the fork arm  130 , an axial hole  160  communicating with the fork opening  150 , and a radial hole  170  communicating with the axial hole  160 . The fork arm  130  includes two forks (not labelled); the fork opening  150  is formed between the two forks. The rotary head  200  is pivotally connected to two ends of the fork arm  130 . The rotary head  200  includes a round housing  210  and a ratchet apparatus (not illustrated) disposed in the round housing  210 , a plurality of positioning recesses  220  disposed on the round housing  210 , and a pivot axis  230  located at the rotary head  200  and passing through the two ends of the fork arm  130 , wherein the pivot axis  230  is perpendicular to the radial hole  170 . 
     The rotary head  200  further includes an output element  240  in a rectangular shape protruding from one end of the round housing  210 , a positioning ball  242  at one side surface of the output element  240 , and a ratchet apparatus (not illustrated) connected to the rectangular output element  240 . A variety of sleeves (not illustrated) in different sizes can be engagedly assembled to the output element  240  by means of the positioning ball  242  of the output element  240 , so as to tighten or loosen the object. 
     In the present embodiment, the drive bar  120  further includes two supporting bolts  132 , an enlarged end  140  and a bar body  142 . The supporting bolts  132  are inserted through the two ends of the fork arm  130  respectively and are pivotally connected between the round housing  210  and the fork arm  130 . The pivot axis  230  is an imaginary line passing through an axle center of each supporting bolt  132 , so that the rotary head  200  is freely rotatable about the pivot axis  230  at the fork opening  150  to certain angles, e.g. from 0 to 270 degrees. The enlarged end  140  is disposed between the fork arm  130  and the bar body  142 . A size of the enlarged end  140  is greater than a size of the bar body  142 . The axial hole  160  and the radial hole  170  are preferably disposed in the enlarged end  140 , and therefore the ratchet wrench  100  of the present embodiment has better strength and provides superior operation quality. 
     Furthermore, the positioning recesses  220  at least includes a first positioning recess  222  disposed on a top of the round housing  210  and a second positioning recess  224  disposed at each of two opposite sides of the round housing  210 . The first positioning recess  222  and the second positioning recess  224  form an included angle of  90  degrees therebetween, so that a user can operate the ratchet wrench  100  in an upright state, i.e. a central axis  244  of the output element  240  is parallel to a rotation axis  144  of the drive bar  120 , or alternatively in a horizontal state, i.e. the central axis  244  of the output element  240  is perpendicular to the rotation axis  144  of the drive bar  120 . The rotation axis  144  is preferably a central line of the drive bar  120  and/or the operation handle  110 . 
     The locking button  250  includes a locking rod  260  disposed in the radial hole  170  and a latch bar  270  disposed in the axial hole  160 . The locking rod  260  is radially movable in association with movement of the latch bar  270 , so that the latch bar  270  can be engaged with or released from any of the positioning recesses  220 . As shown in  FIGS. 1 and 2 , the locking button  250  includes a locking spring  280  for automatically restoring the locking rod  260 , and the latch bar  270  axially move at the same time to protrude out of the axial hole  160 . At this moment, the ratchet wrench  100  is in a locked state/position. 
     In the present embodiment, the radial hole  170  is preferably a blind hole, one end of the locking spring  280  is connected to a bottom of the locking rod  260 , and the other end of the locking spring  280  is in contact with a bottom of the blind hole. When the locking rod  260  radially moves from the locked position (as in  FIG. 2 ) to a released position (as in  FIG. 4 ), the latch bar  270  can be moved to retract from the fork opening  150  to be released from the positioning recess  220 . At this point, the locking spring  280  shown in  FIGS. 3 and 4  are compressed under the action of a force, and the ratchet wrench  100  is in the released state/position. 
     One side of the locking rod  260  corresponding to the axial hole  160  includes a locking recess  252  and a release recess  254  adjacent to the locking recess  252 . When the locking rod  260  is radially movable in the radial hole  170 , the latch bar  270  is allowed to move axially in the axial hole  160 . In other words, when the locking rod  260  moves, one end of the latch bar  270  slides to contact the locking recess  252  or the release recess  254 . The other end of the latch bar  270  is engaged with or released from any positioning recess  220 . A depth of the locking recess  252  is preferably less than a depth of the release recess  254 . 
     The latch bar  270  includes a first bar  272 , a second bar  274  connected to the first bar  272 , and a compression spring  276  connected to the first bar  272  or the second bar  274 . The axial hole  160  of the drive bar  120  includes a first hole  162  and a second hole  164 . The first bar  272  is disposed in the first hole  162 , and the second bar  274  is disposed in the second hole  164 , wherein a diameter of the first bar  272  is larger than a diameter of the second bar  274 , so that the compression spring  276  can receive the second bar  274  easily. Moreover, an end portion of the first bar  272  has a shape corresponding to a shape of each of the positioning recesses  220 , e.g. an arc shape or other suitable shape, so as to be engaged with each positioning recess  220  correspondingly. 
     Two ends of the compression spring  276  are preferably connected to the first bar  272  and a bottom end of the first hole  162 , so that the latch bar  270  keeps having an elastic force to protrude out toward the fork opening  150 . When a button portion  262  of the locking button  250  is pressed, the locking rod  260  moves from the locking recess  252  to the release recess  254 , and the latch bar  270  obtain a space for moving to the release recess  254 . Consequently, a user can easily and rapidly rotate the rotary head  200  to a desired positioning recess  220 . At this moment, the compression spring  276  recoils automatically to be engaged with the positioning recess  220 . 
     In the present embodiment, the locking button  250  can keep a normal close state. The locking rod  260  keeps staying in the locking recess  252  under the action of the locking spring  280 , so that the latch bar  270  protrudes out of the axial hole  160  to be engaged with a corresponding one of the positioning recesses  220 . 
     In the embodiment shown in  FIGS. 1 and 2 , the latch bar  270  of the locking button  250  is preferably engaged with the first positioning recess  222 , so that the user can operate the ratchet wrench  100  in its upright state to tighten or loosen the object. That is to say, the central axis  244  of the output element  240  of the rotary head  200  is parallel to the rotation axis  144  of the drive bar  120  for quick rotation operation. 
     Referring to  FIGS. 3 to 6 , if in some work environments, the user has to operate the ratchet wrench  100  in its horizontal state or in a similar state. By pressing the locking rod  260  of the locking button  250 , the latch bar  270  moves from the locking recess  252  to the release recess  254 . At this point, the latch bar  270  is still engaged with the positioning recess  220  under the action of the compression spring  276 . When the user rotates the rotary head  200  to the second positioning recess  224  or other suitable positioning recess, the compression spring  276  recoils to make the latch bar  270  automatically return to be engaged with the corresponding positioning recess  220 , and then the user can release the locking rod  260 . After the user releases the locking rod  260 , the locking spring  280  recoils to push the locking rod  260  to move from the release recess  254  to the locking recess  252 , so the latch bar  270  can be engaged with the second positioning recess  224  or other corresponding positioning recess  220 , so as to fasten the rotary head  200 . 
     Referring to  FIGS. 7 and 8  showing a second embodiment, the second embodiment is different from the first embodiment in that the locking rod  260  and the latch bar  270  have different structures. As shown in the drawings, one side of the locking rod  260  corresponding to the latch bar  270  includes a first inclined surface  264  and a release recess  268  connected to the first inclined surface  264 , and the latch bar  270  includes a second inclined surface  278  movable along the first inclined surface  264 . The locking rod  260  includes a button portion  262  protruding out of the radial hole  170 , so that the user can press the locking button  250  to operate the same easily. The button portion  262  is preferably integrally formed with the locking rod  260 . However, in other different embodiment, the button portion  262  can also be a part assembled to the locking rod  260 . 
     When the user presses the button portion  262  of the locking rod  260 , the locking rod  260  releases the latch bar  270  and moves relatively to the release recess  268 , so the latch bar  270  is axially movable to the release recess  268 . As shown in  FIG. 8 , by the user&#39;s rotating the rotary head  200 , the round housing  210  or the positioning recess  220  rotatably pushes the latch bar  270 , so the latch bar  270  moves toward the bar body  142  until the rotary head  200  is rotated to the desired positioning recess  220 . However, in other different embodiment, the compression spring in the foregoing embodiment can be employed to enhance reliability of automatic engagement of the latch bar  270  with the positioning recess  220 . 
     On the contrary, upon the user&#39;s releasing the locking rod  260 , the locking spring  280  recoils to push the locking rod  260  to an original position (as in  FIG. 7 ). At this moment, the first inclined surface  264  of the locking rod  260  pushes the second inclined surface  278  of the latch bar  270 , so the latch bar  270  axially protrudes out of the axial hole  160  to be engaged with the corresponding positioning recess  220 . 
     Referring to  FIGS. 9 and 10  showing a third embodiment, the third embodiment is different from the previous two embodiments in that the locking spring  280  is disposed in a different place, and the locking rod  260  and the latch bar  270  have different structures. As shown in the drawings, the drive bar  120  includes an accommodating recess  180  in communication with the radial hole  170 . The locking spring  280  is disposed in the accommodating recess  180 . The radial hole  170  accommodating the locking rod  260  can be a through hole or a blind hole, and the present invention is not limited in this regard. One end of the locking spring  280  is connected to a bottom end of the latch bar  270 , and the other end of the locking spring  280  is in contact with a bottom of the accommodating recess  180 . The accommodating recess  180  is disposed corresponding to the axial hole  160 . The locking spring  280  includes, but not limited to, a compression spring. 
     The locking rod  260  includes a first inclined surface  264  and a limiting portion  266  adjacent to the first inclined surface  264 . The latch bar  270  includes a through hole  271  for insertion of the limiting portion  266  and a second inclined surface  278  movable along the first inclined surface  264 . In the present embodiment, when the user presses the button portion  262  of the locking rod  260 , the first inclined surface  264  of the locking rod  260  pushes the second inclined surface  278  of the latch bar  270 , so the latch bar  270  moves axially toward the accommodating recess  180  until the latch bar  270  is released from the positioning recess  220 . A size of the button portion  262  of the locking rod  260  is greater than a size of the latch bar  270 , so the latch bar  270  can limit the button portion  262  from keeping moving radially. 
     As shown in  FIG. 10 , the user can rotate the rotary head  200  easily until the rotary head  200  is rotated to the desired positioning recess  220 . After the user&#39;s releasing the locking rod  260 , the locking spring  280  recoils and pushes the locking rod  260  to the original position (as shown in  FIG. 9 ). At this moment, the second inclined surface  278  of the latch bar  270  pushes the first inclined surface  264  of the locking rod  260 , so that the button portion  262  of the locking rod  260  protrudes out of the radial hole  170 . At the same time, the latch bar  270  axially moves to protrude out of the axial hole  160  to be engaged with the corresponding positioning recess  220 . Since the limiting portion  266  of the locking rod  260  can be engaged at one side of the latch bar  270 , a radial moving distance of the locking rod  260  is limited. 
     Therefore, the present invention is easy to operate and has a simple structure. By pressing the locking rod  260  of the locking button  250 , rotating the rotary head  200  to the desired positioning recess  222 ,  224 , and then releasing the locking button  250 , the purpose of quickly fastening the rotary head  200  can be achieved. 
     It is to be understood that the above descriptions are merely the preferable embodiment of the present invention and are not intended to limit the scope of the present invention. Equivalent changes and modifications made in the spirit of the present invention are regarded as falling within the scope of the present invention.