Patent Publication Number: US-11376717-B2

Title: Ratchet wrench

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a ratchet wrench and more particularly, to a ratchet wrench having a smaller-sized driving head. 
     A common ratchet wrench on the market, as shown in FIG. 1 of Taiwan Utility Patent No. M492226, includes a wrench head and a ratchet wheel mounted in the wrench head. The ratchet wheel has a connecting hole for connecting with a connecting post of a pass thru socket tool. In other words, the common ratchet wrench needs to be assembled with an additional socket tool for rotating a bolt or nut. However, the additional socket tool not only increases the size of the wrench head, but also the socket tool may be detached from the connecting hole during operation, causing problems in use. 
     Thus, a need exists for a novel ratchet wrench that mitigates and/or obviates the above drawbacks. 
     BRIEF SUMMARY OF THE INVENTION 
     A ratchet wrench according to the present invention includes a body and a ratchet wheel. The body has a head and a handle connected to the head. The ratchet wheel is rotatably disposed in the head and has a first diameter portion, a second diameter portion connected to the first diameter portion, and a driving portion adapted to connect an object. The first diameter portion defines a first diameter in a radial direction of the ratchet wheel. The second diameter portion defines a second diameter less than or equal to the first diameter in the radial direction of the ratchet wheel. 
     In an example, the body is provided with a through-hole at the head in a height direction. On an inner periphery of the through-hole is formed a first annular slot. The ratchet wheel is rotatably disposed in the through-hole about a rotating axis. On an outer periphery of the second diameter portion is formed a second annular slot faced to the first annular slot. A retainer is engaged in the first and second annular slots. 
     In an example, the through-hole penetrates two opposite sides of the head in the height direction. 
     In an example, the ratchet wrench further includes a ratchet device engaged with the ratchet wheel in alternatively engaging relationship. The body is provided with a compartment interconnected with the through-hole. On the outer periphery of the second diameter portion is formed a ratchet teeth portion, which has a third diameter portion disposed between the second annular slot and the ratchet teeth portion. The third diameter portion defines a third diameter less than the second diameter in the radial direction of the ratchet wheel. The ratchet device is arranged in the compartment and includes a pawl engaged with the ratchet teeth portion. 
     In an example, the ratchet wrench further includes a reverse mechanism adapted to control the engaging relationship between the pawl and the ratchet wheel. The reverse mechanism includes a switch pivotally disposed in the head, and the switch is exposed on the head. 
     In an example, the inner periphery of the through-hole is formed with a large diameter section and a small diameter section connected to the large diameter section. The first annular slot is arranged on the large diameter section. The ratchet wheel further has a fourth diameter portion connected to the second diameter portion. The fourth diameter portion defines a fourth diameter less than the third diameter in the radial direction of the ratchet wheel. An inner diameter of the large diameter section is not less than the second diameter, and an inner diameter of the small diameter section is not less than the fourth diameter. 
     In an example, the driving portion is a hole penetrating two opposite sides of the ratchet wheel in the height direction. The driving portion has a first driving section adapted to connect an object and a second driving section connected to the first driving section. An inner diameter of the first driving section is greater than an inner diameter of the second driving section. 
     In an example, the first driving section is a polygonal hole, and the second driving section is a circular hole. 
     In an example, the driving portion is a hole penetrating one side of the ratchet wheel in the height direction, and the driving portion has a first driving section adapted to connect an object. 
     In an example, the through-hole penetrates one side of the head in the height direction, and the body further has a cover portion covering a side of the through-hole. 
     The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial, perspective view of a ratchet wrench of a first embodiment according to the present invention. 
         FIG. 2  is an exploded, perspective view of the ratchet wrench of  FIG. 1 . 
         FIG. 3  is a cross sectional view of the ratchet wrench of  FIG. 1 . 
         FIG. 4  is a cross sectional view of a ratchet wrench of a second embodiment according to the present invention. 
         FIG. 5  is a cross sectional view of a ratchet wrench of a third embodiment according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-3  show a ratchet wrench of a first embodiment according to the present invention. The ratchet wrench includes a body  10 , a ratchet wheel  20  rotatably disposed in the body  10  about a rotating axis A 20 , a ratchet device  30  engaged with the ratchet wheel  20  in alternatively engaging relationship, and a reverse mechanism  40  adapted to control the engaging relationship between the ratchet device  30  and the ratchet wheel  20 . 
     The body  10  has a head  11  and a handle  12  connected to the head  11 . The body  10  is provided with a through-hole  13  at the head  11  in a height direction, and a compartment  14  interconnected with the through-hole  13 . The head  11  has a first portion  111  and a second portion  112  opposite to the first portion  111  and connected to the handle  12 . Further, the first portion  111  may be disposed at the front end of the head  11  in a length direction. In the embodiment, the through-hole  13  may penetrate two opposite sides of the head  11  in the height direction, and an inner periphery of the through-hole  13  may be formed a large diameter section  131 , a small diameter section  132  connected to the large diameter section  131 , and a first annular slot  133  arranged around the large diameter section  131 . 
     The ratchet wheel  20  is rotatably disposed in the through-hole  13  of the head  11  about the rotating axis A 20  and has a first diameter portion  21 , a second diameter portion  22  connected to the first diameter portion  21 , a third diameter portion  23 , a fourth diameter portion  24  connected to the second diameter portion  22 , and a driving portion  25  adapted to connect an object to be driven. 
     The first diameter portion  21  defines a first diameter D 21  in a radial direction of the ratchet wheel  20 . The second diameter portion  22  defines a second diameter D 22  less than or equal to the first diameter D 21  of the first diameter portion  21  in the radial direction of the ratchet wheel. In the embodiment, the second diameter D 22  of the second diameter portion  22  is less than the first diameter D 21  of the first diameter portion  21 . An outer periphery of the first diameter portion  21  is at least aligned with an outer edge of the first portion  111  of the head  11  in the height direction. Further, the outer periphery of the first diameter portion  21  may be both aligned with the outer edges of the first portion  111  and the second portion  112  of the head  11 . Thus, the special design of the ratchet wheel  20  can allow longer bolts to pass through without the need to assemble the additional socket tool to reduce the size of the head  11  and effectively maintain the structural strength of the ratchet wheel  20 . 
     On an outer periphery of the second diameter portion  22  is formed a second annular slot  221  faced to the first annular slot  133 , and a ratchet teeth portion  222  engaged with the ratchet device  30 . A retainer  26  is engaged in the first and second annular slots  133  and  211  to prevent the ratchet wheel  20  detaching from the through-hole  13 . 
     The third diameter portion  23  is disposed between the second annular slot  221  and the ratchet teeth portion  222  and defines a third diameter D 23  less than the second diameter D 22  of the second diameter portion  22  in the radial direction of the ratchet wheel  20 . The fourth diameter portion  24  defines a fourth diameter D 24  less than the third diameter D 23  of the third diameter portion  23  in the radial direction of the ratchet wheel  20 . Further, an inner diameter of the large diameter section  131  is not less than the second diameter D 22  of the second diameter portion  22 , and an inner diameter of the small diameter section  132  is not less than the fourth diameter D 24  of the fourth diameter portion  24 . 
     In the embodiment, the driving portion  25  is a hole penetrating two opposite sides of the ratchet wheel  20  in the height direction. In other words, the design of the ratchet wheel  20  of the embodiment can be used for a penetrating ratchet wrench. Understandably, the driving portion  25  may also be formed into a convex column shape to directly engage the socket. The driving portion  25  has a first driving section  251  adapted to connect the object and a second driving section  252  connected to the first driving section  251 , and an inner diameter of the first driving section  251  is greater than an inner diameter of the second driving section  252 . The first driving section  251  may be in the shape of a polygonal hole or a petal hole for connecting and driving the object to be driven, and the second driving section  252  may be in the shape of a circular hole or a square hole adapted to be passed by the longer object to be driven. 
     The ratchet device  30  is arranged in the compartment  14  and includes a pawl  31  engaged with the ratchet teeth portion  222  of the ratchet wheel  20 . The reverse mechanism  40  is adapted to control the engaging relationship between the pawl  31  and the ratchet teeth portion  222  of the ratchet wheel  20 . The reverse mechanism  40  includes a switch  41  pivotally disposed in the second portion  112  of the head  11 . Further, the switch  41  is exposed on the second portion  112  of the head  11  for the user to switch. 
       FIG. 4  shows a cross sectional view of a ratchet wrench of a second embodiment according to the present invention. The second embodiment is substantially the same as the first embodiment but is mainly different from the second embodiment by that the driving portion  25   a  may be in the shape of a hole penetrating one side of the ratchet wheel  20   a  in the height direction. The driving portion  25   a  has a first driving section  251   a  adapted to connect an object. In addition, the fourth diameter D 24  is only half of the second diameter D 22 . In other words, the design of the ratchet wheel  20   a  of this embodiment can be used for a non-penetrating ratchet wrench. 
       FIG. 5  shows a cross sectional view of a ratchet wrench of a third embodiment according to the present invention. The third embodiment is substantially the same as the first embodiment but is mainly different from the second embodiment by that the through-hole  13  penetrates one side of the head  11  in the height direction, and the body  10  further has a cover portion  15  covering a side of the through-hole  13 . Therefore, the ratchet wheel  20   b  can correspond to the cover portion  15  without the fourth diameter portion  24  (as shown in  FIG. 2 ) in the foregoing embodiment. In addition, the driving portion  25   b  may be in the shape of a hole but does not penetrate the two opposite sides of the ratchet wheel  20   b , and only penetrates one side of the ratchet wheel  20   b  to have a first driving section  251   b.    
     Conclusively, the above-mentioned embodiment of the present invention provides a ratchet wrench with a smaller-sized drive head, whereby the second diameter D 22  of the second diameter portion  22  being smaller than or equal to the first diameter D 21  of the first diameter portion  21 , the special design of the ratchet wheels  20 ,  20   a ,  20   b  reduces the size of the head  11 , and effectively maintains the structural strength of the ratchet wheels  20 ,  20   a ,  20   b.    
     Although specific embodiments have been illustrated and described, numerous modifications and variations are still possible without departing from the scope of the invention. The scope of the invention is limited by the accompanying claims.