Patent Publication Number: US-2018036869-A1

Title: High torque ratchet wrench

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to wrench tools, and more particularly, to a high torque wrench. 
     2. Description of the Related Art 
     As shown by  FIG. 1 , a traditional ratchet wrench comprises a wrench body  1 , a ratchet wheel  3 , a direction switching member  5 , and a ratchet block  6 . The wrench body  1  includes a head  2  and a handle. The head  2  is provided with a first cavity  2   a , a second cavity  2   b , and a third cavity  2   c  between the first cavity  2   a  and the second cavity  2   b . The center of the third cavity  2   c  is included in the first cavity  2   a . The ratchet wheel  3  is disposed in the first cavity  2   a  and peripherally provided with plural teeth  4 . The direction switching member  5  is pivotally disposed in the second cavity  2   b . The ratchet block  6  is disposed in the third cavity  2   c  and between the ratchet wheel  3  and the direction switching member  5 , so as to be engaged with the teeth  4 . When the direction switching member  5  is optionally moved between a first position and a second position, the ratchet block  6  is correspondingly engaged with the teeth  4 . 
     Recently, the requirement toward the torque provided by a ratchet wrench is higher for stably outputting a higher torque value. However, during the manufacturing process of the ratchet wrench, different components are usually supplied by different factories; also, manufacturing accuracy of the same component model made by each factory are not identical. Therefore, when assembling the components, an inaccuracy often occurs between the held face of the ratchet block  6  and the inner wall of the third cavity  2   c , such that a gap exists between the teeth  4  and the ratchet block  6 . As a result, the teeth  4  and the ratchet block  6  are prevented from being completely matched with each other, producing an instable torque output. 
     If a stable high torque output is required, the inaccuracy tolerance of each component against other components shall be accurately calculated, so as to maintain a tight adherence between the held surface of the ratchet block  6  and the inner wall of the third cavity  2   c , whereby there is substantially no gaps existing between the teeth  4  and the ratchet block  6 , and a stable high torque output is achieved. 
     However, in order to increase the manufacturing accuracy of each component, not only the cost is higher, but also the different accuracy standards provided by different factories shall be considered. Therefore, unless an integrated production line is applied, a ratchet wrench with stable high torque output is difficult to be achieved. 
     Thus, the issue of stably outputting a high torque without increasing the present assembling method and process needs to be resolved. 
     SUMMARY OF THE INVENTION 
     For improving the aforementioned issues, embodiments of the present invention disclose a high torque ratchet wrench. By use of two torque blocks disposed on two sides of the ratchet block, when the ratchet block is engaged with the ratchet wheel, a lateral side of the ratchet block is pushed by the torque block. With one side of the torque block is formed in an arc shape, a biasing effect thereof is provided, such that the torque block biasedly moves to an appropriate position along the rotation of the ratchet wheel, whereby the a surface of the ratchet block remains being pushed by the torque block. Therefore, the gap between the relative components due to manufacturing inaccuracy is eliminated. The structural tightness is enhanced, and the high torque output is stably provided. 
     For achieving the aforementioned objectives, embodiments of the present invention provide a high torque ratchet wrench, comprising: 
     a main body including a handle and a head, the head provided with a first cavity, a second cavity connected with one side of the first cavity, and a third cavity disposed between and connected with the first cavity and the second cavity; 
     a ratchet wheel rotatably disposed in the first cavity and peripherally provided with plural teeth; 
     a direction switching assembly movably disposed in the second cavity; 
     a ratchet block movably disposed in the third cavity and between the ratchet wheel and the direction switching assembly, the ratchet block having two opposite sides thereof provided with a first held surface and a second held surface, wherein the direction switching assembly optionally moves between a first position and a second position, such that the direction switching assembly forces the ratchet block to engage the ratchet wheel; and 
     two torque blocks disposed in the third cavity and facing the ratchet block, wherein when the direction switching assembly is at the first position or the second position, the first held surface or the second held surface of the ratchet block is correspondingly pushed by one of the torque blocks. 
     With such configuration, the objective of the present invention is that by use of the torque blocks pushing the ratchet block, a tooth portion of the ratchet block is engaged with the teeth without gaps therebetween, so as to enhance the tightness of the engagement between the ratchet block and the ratchet wheel. As a result, during the rotation operation of the present invention, a high torque is stably output. Therefore, the engagement between the components is improved and the high torque output is achieved without increasing the manufacturing accuracy of different components and the cost and time of doing so or varying the overall producing process. Also, the structural strength of the ratchet wrench provided by the present invention is higher than the traditional ratchet wrench, so that the service life of the ratchet wrench provided by the present invention is enhanced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially sectional view of a known ratchet wrench. 
         FIG. 2  is a perspective view of a ratchet wrench in accordance with an embodiment of the present invention. 
         FIG. 3  is an exploded view of the ratchet wrench in accordance with an embodiment of the present invention. 
         FIG. 4  is a partial schematic view of an embodiment of the present invention, illustrating the first held surface pushed by the torque block. 
         FIG. 5  is another partial schematic view of an embodiment of the present invention, illustrating the second held surface pushed by the torque block. 
         FIG. 6A  is another partial schematic view of an embodiment of the present invention, illustrating the torque block biasedly moved. 
         FIG. 6B  is another partial schematic view of an embodiment of the present invention, illustrating the torque block biasedly moved to an appropriate position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The aforementioned and further advantages and features of the present invention will be understood by reference to the description of the preferred embodiment in conjunction with the accompanying drawings where the components are illustrated based on a proportion for explanation but not subject to the actual component proportion. 
     Referring to  FIG. 2  to  FIG. 6B , a ratchet wrench of an embodiment of the present invention comprises a main body  10 , a ratchet wheel  20 , a direction switching assembly  30 , a ratchet block  40 , two torque blocks  50 , a resilient member  60 , and a cover  70 . 
     The main body  10  includes a handle  11  and a head  12 . The head  12  is provided with a first cavity  121 , a second cavity  122 , and a third cavity  123  passing therethrough. One side of the first cavity  121  is connected with the second cavity  122 . The third cavity  123  is disposed between and connected with the first cavity  121  and the second cavity  122 . The center of the third cavity  123  is included in the first cavity  121 . Two sides of the third cavity  123  are disposed with a groove  124 , respectively. 
     The ratchet wheel  20  is rotatably disposed in the first cavity  121  and peripherally provided with plural teeth  21 . The ratchet wheel  20  includes a driving portion  22 , wherein the central axis of the driving portion  22  is arranged in axial alignment with the center of the first cavity  121 . 
     The direction switching assembly  30  is movably disposed in the second cavity  122  and movable between a first position and a second position. The direction switching assembly  30  includes a direction switching member  31  and a pushing member  32 . The direction switching member  31  is transversely provided with a housing  311 , and the pushing member  32  is received in the housing  311 . The user turns the direction switching member  31  to switch the direction. Furthermore, the pushing member  32  includes a spring  321  and a pushing plate  322 . The spring  321  resists against a part between the pushing plate  322  and the housing  311 . In an embodiment of the present invention, the pushing plate  322  is formed in an E shape. The pushing plate  322  is provided with a transverse rod  323 , and the spring  321  is mounted around the transverse rod  323 . 
     The ratchet block  40  is movably disposed in the third cavity  123  and placed between the ratchet wheel  20  and the direction switching assembly  30 . Two opposite sides of the ratchet block  40  are provided with a first held surface  41  and a second held surface  42 . A front side of the ratchet block  40  is provided with a tooth portion  43 ; a rear side of the ratchet block  40  is provided with a resisting face  44 . The first held surface  41  and the second held surface  42  respectively face two grooves  124 . The tooth portion  43  is allowed to be engaged with the teeth  21 , and the resisting face  44  is pushed by the pushing plate  322 . 
     When the direction switching assembly  30  optionally moves between the first position and the second position, the tooth portion  43  of the ratchet block  40  is engaged with the teeth  21 , such that the ratchet wheel  20  rotates in clockwise or counterclockwise direction, whereby the user fastens or loosens a screw or bolt. 
     The two torque blocks  50  are movably disposed in the two grooves  124 , respectively. Two opposite sides of each torque block  50  are provided with a received side  51  and a resisting side  52 . Also, the top surface of each torque block  50  is provided with a combining bore  53 . The received side  51  is matched with and attached to the inner wall of the corresponding groove  124 . The resisting side  52  protrudes from or flushes with two sides of the groove  124 . As shown by  FIG. 4 , when the direction switching assembly  30  is at the first position, the first held surface  41  is pushed by the resisting side  52  of the torque block  50  on the right side of  FIG. 4 ; when the direction switching assembly  30  is at the second position, the second held surface  42  is pushed by the resisting side  52  of the torque block  50  on the left side of  FIG. 5 . 
     In addition, in an embodiment of the present invention, the first held surface  41  and the second held surface  42  are flat-shaped, while the received side  51  is arc-shaped and the resisting side  52  is flat-shaped. When the resisting side  52  of one of the torque blocks  50  pushes the first held surface  41  or the second held surface  42 , the arc-shaped received side  51  provides a biasing effect upon the torque block  50 , such that the torque block  50  biasedly move to an appropriate position along the rotation of the ratchet wheel  20 , whereby one of the first held surface  41  and the second held surface  42  remains being pushed by the corresponding resisting side  52 , as shown by  FIG. 6A  and  FIG. 6B . Therefore, the gaps between relative components due to inaccurate manufacturing process are eliminated, and the structural tightness is enhanced. 
     In an embodiment of the present invention, the resilient member  60  is formed in a reversed U shape. The resilient member  60  includes a connecting shaft  61  and two feet  62 . The two feet  62  are fixed in the two combining bores  53 . The resilient member  60  connects the two torque blocks  50  through the connecting shaft  61  and limits the torque blocks  50  in the two grooves  124 , so as to prevent the two torque blocks  50  from being detached from the two grooves  124 . Also, in the embodiment of the present invention, the resilient member  60  is disposed at a height which is higher than the height at which the ratchet block  40  is disposed in the third cavity  123 , such that the resilient member  60  does not interfere with the ratchet block  40  when the direction switching assembly  30  optionally moves between the first position and the second position. 
     A cover  70  is fastened at the head  12  and covers the first cavity  121 , the second cavity  122 , and the third cavity  123 . The cover  70  includes a through hole  71 , through where the driving portion  22  protrudes. Also, an O-ring  80  is mounted between the driving portion  22  and the cover  70  for preventing the cover  70  from being detached from the driving portion  22 . 
     Referring to  FIG. 3  to  FIG. 4 ,  FIG. 6A , and  FIG. 6B , the direction switching member  31  is at the first position. When the user turns the direction switching member  31  to the position on the right side of the drawings, the tooth portion  43  is engaged with the teeth  21 , and the user is able to grasp the handle  11 , thereby driving the ratchet wheel  20  in counterclockwise direction to fasten or loosen a screw or bolt. In addition, the torque block  50  on the right side of the drawings is biasedly moved to an appropriate position along the rotation of the ratchet wheel  20 , such that the first held surface  41  maintains being pushed by the corresponding resisting side  52 . Therefore, gaps between relative components due to manufacturing inaccuracy are eliminated, so that the tooth portion  43  is completely engaged with the teeth  21  without gaps, thus increasing the tightness between the ratchet block  40  and the ratchet wheel  20  and stabilizing the high torque output. 
     Referring to  FIG. 2 ,  FIG. 5 ,  FIG. 6A , and  FIG. 6B , the direction switching member  31  is at the second position. When the user turns the direction switching member  31  to the position on the left side of the drawings, the tooth portion  43  is engaged with the teeth  21 , and the user is able to grasp the handle  11 , thereby driving the ratchet wheel  20  in clockwise direction to fasten or loosen a screw or bolt. In addition, the torque block  50  on the left side of the drawings is biasedly move to an appropriate position along the rotation of the ratchet wheel  20 , such that the second held surface  42  maintains being pushed by the corresponding resisting side  52 . Therefore, gaps between relative components due to manufacturing inaccuracy are eliminated, so that the tooth portion  43  is completely engaged with the teeth  21  without gaps, thus increasing the tightness between the ratchet block  40  and the ratchet wheel  20  and stabilizing the high torque output. 
     To sum up, the high torque ratchet wrench provided by the embodiment of the present invention, by use of the torque blocks  50  biasedly moved to the appropriate position along the rotation of the ratchet wheel  20 , the first held surface  41  or the second held surface  42  remains being pushed by the corresponding resisting side  52 , such that gaps between relative components due to manufacturing inaccuracy are eliminated. As a result, the tooth portion  43  is completely engaged with the teeth  21 , thus increasing the tightness between the ratchet block  40  and the ratchet wheel  20 , thereby providing a stable high torque output. Therefore, the stable high torque output is achieved without increasing the manufacturing accuracy of different components and the cost and time of doing so or varying the overall producing process. Also, the structural strength of the ratchet wrench provided by the present invention is higher than the traditional ratchet wrench, so that the service life of the ratchet wrench provided by the present invention is enhanced. 
     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.