Patent Publication Number: US-2017361433-A1

Title: Ratchet wrench with positioning structure

Description:
TECHNICAL FIELD 
     The present invention relates to a ratchet wrench and, in particular, to a ratchet wrench with a positioning structure, which is freely rotatable to certain angles. 
     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 screw blots, screws, or the likes, so it replaces a traditional wrench in many places. 
     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. screw nuts and screw 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. 
     Accordingly, the inventor made various studies to solve the above-mentioned problems, on the basis of which the present invention is accomplished. 
     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 transversely pushing a lock button to move. 
     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 located at the rotary head and passing through the two ends of the fork arm, wherein the pivot axis is parallel 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 transversely movable in association with movement of the latch bar, and the latch bar is engaged with or disengaged from any of the positioning recesses. 
     The present invention further has the following merits. By pushing backwards and forwards or moving reciprocately the locking button, the rotary head can be fastened or released quickly. Therefore, the present invention has the advantages of a simple structure and easy operations. In addition, a retaining structure of the present invention serves to enhance the stability and reliability of the locking button in a locked position or a released position. 
    
    
     
       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 illustrating a ratchet wrench with a positioning structure according to the present invention; 
         FIG. 2  is a partial cross-sectional view illustrating the ratchet wrench with the positioning structure according to the present invention; 
         FIG. 3  is another perspective view illustrating the ratchet wrench with the positioning structure according to the present invention; 
         FIG. 4  is a partial cross-sectional view of  FIG. 3 ; 
         FIG. 5  is still another perspective view illustrating the ratchet wrench with the positioning structure according to the present invention; and 
         FIG. 6  is a partial cross-sectional view of  FIG. 5 . 
     
    
    
     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 relates to a ratchet wrench  100  with a positioning structure. The ratchet wrench  100  comprises 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  which receives 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 . As shown in the drawing, the fork arm  130  includes two forks (not labelled), and the fork opening  150  is formed between 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 parallel 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 . Moreover, the ratchet apparatus is disposed inside the round housing  210 , and a variety of sleeves (not illustrated) in different sizes can be engagedly assembled by means of the positioning ball  242  of the output element  240 , so that the object can be tightened or loosened. The ratchet apparatus is a conventional apparatus, so a detailed description thereof is omitted for brevity. 
     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 two ends of the fork arm  130  respectively and are fixed 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 . In other words, the locking button  250  is also 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 positioning recess  220  is preferably in a shape corresponding to the shape of the latch bar  270 , so as to facilitate engagement of the latch bar  270  with the positioning recess  220 . 
     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 . It is preferable that two ends of the locking rod  260  protrude out of two openings of the radial hole  170 , so as to facilitate the user&#39;s pressing or moving back and forth the locking rod  260 . The locking rod  260  transversely moves from a release position (see  FIG. 4 ) to a locked position (see  FIG. 2 ), so that the latch bar  270  is driven to move to protrude into the fork opening  150  and be engaged with any of the positioning recesses  220 . 
     In the embodiment shown in  FIGS. 2, 4 and 6 , 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 , and the other side of the locking rod  260  includes a first indentation  256  and a second indentation  258 . When the locking rod  260  transversely moves in the radial hole  170 , the latch bar  270  is driven to move axially in the axial hole  160 . In other words, when the locking rod  260  moves, one end of the latch bar  270  is slidable to contact the locking recess  252  or the release recess  254 , and the other end of the latch bar  270  is engaged with or released from any of the positioning recesses  220  of the rotary head  200 , wherein a depth/size of the locking recess  252  is less than a depth/size of the release recess  254 . 
     In the present embodiment, 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  communicating with the first hole  162 . The first bar  272  is received in the first hole  162 , and the second bar  274  is received in the second hole  164 , wherein the first bar  272  has a greater diameter than a diameter of the second bar  274 , so that the compression spring  276  can receive the second bar  274 . Moreover, an end portion of the first bar  272  is in a shape corresponding to the shape of each positioning recess  220 , e.g. having an arc shape or other suitable shape, so as to be engaged with each positioning recess  220  correspondingly. 
     In the present embodiment, 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 as to exert a spring force to force the latch bar  270  to protrude outward in a direction toward the fork opening  150 . When the locking rod  260  of the locking button  250  transversely moves from the release recess  254  to the locking recess  252 , the latch bar  270  is forced by the compression spring to protrude outwardly of the axial hole  160  to be engaged with any of the positioning recesses  222 ,  224 . On the contrary, when the locking rod  260  transversely moves from the locking recess  252  to the release recess  254 , the compression spring  276  recoils to pull back the latch bar  270 . At this point, one end of the latch bar  270  is disengaged from the rotary head  200 , and the other end of the latch bar  270  is in contact with the release recess  254 . Accordingly, the user only needs to moves the locking rod  260  back and forth along a direction of the pivot axis  230  to fasten or release the rotary head  200  quickly. 
     In order to enhance the stability and reliability of the locking button  250  in the locked position or the released position, the present embodiment further includes a retaining structure  280 . The retaining structure  280  is disposed in a retaining recess  180  of the drive bar  120 . The retaining recess  180  is preferably on the same line (not illustrated) as the axial hole  160 , so as to provide a stronger retaining force. The retaining structure  280  includes a retaining element  282  and a retaining spring  284  connected to the retaining element  282 , wherein the first indentation  256  and the second indentation  258  are disposed corresponding to the retaining recess  180 . 
     According to the embodiment shown in  FIGS. 2, 4 and 6 , the first indentation  256  is preferably disposed corresponding to the locking recess  252 , and the second indentation  258  is preferably disposed corresponding to the release recess  254 , so that the locking button  250  can be retained in the lock position or the released position. The retaining element  282  is preferably a spherical rolling ball, an arc-shaped rolling ball, or the likes. The retaining spring  284  is a compression spring, so as to flexibly fasten the locking rod  260  in the first indentation  256  or the second indentation  258 . 
     Please refer to  FIGS. 5 and 6  which are still another perspective view and a partial cross-sectional view illustrating the ratchet wrench with the positioning structure according to the present invention, wherein a center of the output element of the rotary head  200  is perpendicular to the axis of the drive bar  120 . When in some work environments the user has to adjust the central axis  244  of the rotary head  200  to be perpendicular to the rotation axis  144  of the drive bar  120 , the user transversely pushes the locking rod  260  of the locking button  250 , and at the same time the latch bar  270  moves from the locking recess  252  to the release recess  254 . 
     At this point, the rotary head  200  is free to rotate to a position wherein the central axis  244  of the output element  240  is perpendicular to the rotation axis  144  of the drive bar  120 , so that the second positioning recess  224  is aligned with the axial hole  160 . Then, the user pushes in an opposite direction the locking rod  260  of the locking button  250 , so at the same time the latch bar  270  moves from the release recess  254  to the locking recess  252 , and thereby the latch bar  270  is engaged with the second positioning recess  224 . Therefore, an object can be tightened or loosened when the wrench is operated horizontally. 
     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.