Patent Publication Number: US-2022226975-A1

Title: Dislodgement Alert Structure of Torque Wrench

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a hand tool and more particularly to a dislodgement alert structure of a torque wrench, wherein the dislodgement alert structure includes a dislodgeable element with relatively long turning sides that allow the elastic modulus of an elastic element of the dislodgement alert structure to be reduced. 
     2. Description of Related Art 
     Some hand tools have an adjustable torque mechanism that allows the torque to be applied during operation to be set. A conventional torque mechanism is generally so designed that when the torque applied reaches a preset torque value, an element of the mechanism is dislodged, thereby making a clicking sound to alert the user to the fact that the torque value has been reached, and to warn the user not to operate the hand tool any further. Referring to  FIG. 1 , a conventional torque wrench  10  is provided with a dislodgeable element  11 , a rod  12 , a supporting base  13 , and a tube  14 . The rod  12 , the dislodgeable element  11 , and the supporting base  13  are sequentially arranged in the tube  14 . The dislodgeable element  11  is a cube, all of whose edges are of equal lengths. The rod  12  has a bottom portion provided with a recessed portion  121 . The supporting base  13  has a top side provided with a recessed portion  131  facing the recessed portion  121  and has a bottom portion to which a spring  132  applies an elastic force. The dislodgeable element  11  is provided between the recessed portion  121  of the rod  12  and the recessed portion  131  of the supporting base  13 , with the spring  132  pushing the supporting base  13  and the dislodgeable element  11  toward the rod  12 . When the force acting on the rod  12  is greater than a preset pressure of the spring  132 , the dislodgeable element  11  is pushed by the rod  12  and in turn pushes the recessed portion  131  downward. The recessed portion  121  of the rod  12  will also turn the dislodgeable element  11  such that the rod  12  is moved sideways and hits the tube  14 , thereby making a sound to alert the user. 
     The six sides of the dislodgeable element  11  of the conventional torque wrench  10  have edges of equal lengths. Moreover, when a predetermined torque value is reached, the rod  12  will be displaced, with the recessed portion  121  causing an angular change of the dislodgeable element  11  such that the dislodgeable element  11  is turned between the recessed portion  121  of the rod  12  and the recessed portion  131  of the supporting base  13 . As the pushing force required to dislodge, or turn, the dislodgeable element  11  is not great, the spring  132  must have a relatively high elastic modulus in design so as to prop the supporting base  13  while allowing the dislodgeable element  11  to be dislodged at predetermined torque values. When having a relatively high elastic modulus, however, the spring  132  will be under a relatively great load and may therefore undergo elastic fatigue relatively easily, meaning the precision of the spring  132  is very likely to be lowered after long-term use. Furthermore, when the spring  132  has a relatively high elastic modulus, a user is required to exert a relatively great rotating force in order to adjust, in particular to increase, the torque value, and this reduces the ease of operation. 
     BRIEF SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a dislodgement alert structure in which a dislodgeable block has a greater length in the turning direction than the height of the dislodgeable block, and which allows the load on an elastic element of the dislodgement alert structure to be lowered. 
     To achieve the foregoing objective, the present invention provides a dislodgement alert structure of a torque wrench, wherein the dislodgement alert structure includes a tube, a tool head, a supporting base, and a dislodgeable element. 
     The tube has a receiving chamber that penetrates the front end of the tube. The front-rear direction of the tube is defined as a longitudinal direction, and the lateral direction of the tube is defined as a transverse direction. 
     The tool head has a head portion at the front end and a front recessed portion at the rear end. The front end and the rear end of the tool head are connected by a rod. The tool head is pivotally provided in the receiving chamber of the tube and can be pivoted in the lateral, or transverse, direction of the tube. The head portion is exposed from the tube. The front recessed portion is provided in the receiving chamber. When no force is applied to the tool head, there is a gap between the rod and the periphery of the receiving chamber. 
     The supporting base is provided in the receiving chamber of the tube. The front end of the supporting base is provided with a rear recessed portion facing the front recessed portion. The rear end of the supporting base is provided with an elastic element so that the supporting base can generate an elastic force acting toward the tool head. 
     The dislodgeable element has a front end and a rear end, each of which has a width in the lateral, or transverse, direction of the tube. The dislodgeable element further has a height in the longitudinal direction of the tube. The length of the height is less than the length of the widths. 
     The dislodgement alert structure of the torque wrench is so designed that the widths of the dislodgeable element are increased in length to make it more difficult to turn the dislodgeable element than in the prior art, thereby allowing the elastic element at the rear end of the supporting base to have a relatively low elastic modulus, which not only facilitates torque adjustment, but also reduces inaccurate measurement attributable to a damaged spring. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In order for the examiner to better understand the objectives, features, and intended effect of the present invention, two preferred embodiments are detailed below with reference to the accompanying drawings, in which: 
         FIG. 1  is a sectional view of a conventional torque wrench; 
         FIG. 2  is a sectional view of the torque wrench according to a preferred embodiment of the present invention; 
         FIG. 3  is a partial sectional view of the torque wrench in  FIG. 2 , showing in particular how the tool head, the supporting base, and the dislodgeable element are coupled together; 
         FIG. 4  is a perspective view of the dislodgeable element of the torque wrench in  FIG. 2 ; 
         FIG. 5  is similar to  FIG. 3  except that the dislodgeable element is subjected to a force; 
         FIG. 6  is similar to  FIG. 5  except that the torque applied by the torque wrench has reached a predetermined torque value, causing dislodgement of the dislodgeable element; and 
         FIG. 7  is a perspective view of the dislodgeable element in a second preferred embodiment of the invention, wherein the dislodgeable element has a longer transverse width than its longitudinal depth. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 2  to  FIG. 4 , the torque wrench  20  according to a preferred embodiment of the present invention includes a tube  30 , a tool head  40 , a supporting base  50 , and a dislodgeable element  60 . 
     The tube  30  has a receiving chamber  31  that penetrates the front and rear ends of the tube  30 . The rear end of the tube  30  is pivotally provided with an adjustment handle  32 . The adjustment handle  32  can be rotated at the rear end of the receiving chamber  31  and is provided with an adjusting block  321 . The adjusting block  321  can be moved forward or backward in the receiving chamber  31  as the adjustment handle  32  is rotated. The front end-rear end direction of the tube  30  is defined as a longitudinal direction. The lateral direction of the tube  30  is defined as a transverse direction. 
     The tool head  40  has a head portion  41  at the front end and a front recessed portion  42  at the rear end. The front and rear ends of the tool head  40  are connected by a rod  43 . The rear end of the tool head  40  is provided in the receiving chamber  31  of the tube  30 . The head portion  41  is exposed from the tube  30 . The front recessed portion  42  is provided in the receiving chamber  31 . There is a gap G between the front recessed portion  42  and the peripheral wall of the receiving chamber  31  when the tool head  40  is not subjected to an applied force. A connecting element  44  is inserted through the tool head  40  and the tube  30  so that the rod  43  can be pivoted about an axis defined by the connecting element  44 . The direction of the axis defined by the connecting element  44  is defined as an axial direction. 
     The supporting base  50  is provided in the receiving chamber  31  of the tube  30 . The front end of the supporting base  50  is provided with a rear recessed portion  51  that faces the front recessed portion  42  of the tool head  40 . The rear end of the supporting base  50  is provided with an elastic element  52  in order for the supporting base  50  to generate an elastic force that acts in the longitudinal direction of the tool head  40 . The elastic element  52  has one end abutting against the rear end of the supporting base  50  and the opposite end abutting against the adjusting block  321  of the adjustment handle  32  of the tube  30 . By varying the position of the adjusting block  321  in the receiving chamber  31  of the tube  30 , the length of the elastic element  52  can be adjusted so as to adjust the magnitude of the elastic force applied by the elastic element  52  to the supporting base  50 . The closer the adjusting block  321  is to the supporting base  50 , the greater the elastic force generated by the elastic element  52 . 
     The dislodgeable element  60  is provided between the tool head  40  and the supporting base  50 . Each of the front and rear ends of the dislodgeable element  60  has a contact surface  61  for contact with the front recessed portion  42  of the tool head  40  or the rear recessed portion  51  of the supporting base  50 . The contact surfaces  61  are quadrilaterals each having two widths  611  in the lateral, or transverse, direction of the tube  30  and two depths  612  perpendicular to the widths  611 , wherein the two widths  611  and the two depths  612  have a length L 1  and a length L 2  respectively. In this embodiment, the length L 1  of the widths  611  and the length L 2  of the depths  612  are equal such that the contact surfaces  61  are squares. The dislodgeable element  60  further has a height  62  in the longitudinal direction of the tube  30 . The length H of the height  62  is less than the lengths L 1  and L 2  of the widths  611  and depths  612  of the contact surfaces  61 . The ratio of the length L 1  of the widths  611  to the length H of the height  62  is 1.3-2.5, and so is the ratio of the length L 2  of the depths  612  to the length H of the height  62 . The relatively long widths  611  and depths  612  of the contact surfaces  61  not only contribute to a relatively large area of contact between the dislodgeable element  60  and the front recessed portion  42  and between the dislodgeable element  60  and the rear recessed portion  51 , but also allow the rear recessed portion  51  of the supporting base  50  to push the dislodgeable element  60  toward the tool head  40  such that the tool head  40  is subjected to the elastic force of the elastic element  52 , is thereby kept from pivoting toward either lateral side of the tube  30 , and can therefore apply a predetermined torque to a workpiece (not shown). 
     Before using the torque wrench  20 , referring to  FIG. 5  and  FIG. 6 , the position of the adjusting block  321  in the receiving chamber  31  of the tube  30  can be adjusted with the adjustment handle  32  in order to adjust the compressed length of the elastic element  52 , the goal being for the elastic element  52  to generate an elastic force and thereby push the supporting base  50 , the dislodgeable element  60 , and the tool head  40  as desired. When a force is applied to the torque wrench  20  by a user holding the adjustment handle  32 , the head portion  41  of the tool head  40  can apply a force to, and thereby tighten or loosen, an object such as a workpiece or socket, and in the meantime, the front recessed portion  42  at the rear end of the rod  43  will generate a force that is in the opposite direction of the force applied by the user and acts on the corresponding contact surface  61  of the dislodgeable element  60 . The greater the force applied by the user is, the higher the torque generated by the head portion  41  of the tool head  40  will be, and the greater the opposite-direction force generated by the front recessed portion  42  will also be. As the lengths L 1  and L 2  of the widths  611  and depths  612  of the contact surfaces  61  of the dislodgeable element  60  are greater than the length H of the height  62  of the dislodgeable element  60 , the areas of contact between the contact surfaces  61  and the front recessed portion  42  of the tool head  40  and the rear recessed portion  51  of the supporting base  50  are relatively great. Compared with its prior art counterparts, therefore, the dislodgeable element  60  can better distribute, and is less likely to be turned by, the force applied by the front recessed portion  42 . It follows that the elastic element  52  is allowed to prop the supporting base  50  with a smaller elastic force than in the prior art. That is to say, the elastic element  52  may have a lower elastic modulus than in the prior art. In that case, the adjusting block  321  of the adjustment handle  32  will be subjected to a relatively small elastic force, meaning the elastic force that must be overcome in order to adjust the position of the adjusting block  321 , i.e., to adjust the torque value, will be relatively small, and the adjustment can be made with relatively great ease via the adjustment handle  32 . Furthermore, when the force applied to the head portion  41  is so great as to turn the dislodgeable element  60  between the front recessed portion  42  of the tool head  40  and the rear recessed portion  51  of the supporting base  50 , the front recessed portion  42  generates a lateral force. More specifically, the tool head  40  is pivoted about an axis defined by the connecting element  44  when applying a force, and the front recessed portion  42  pushes, and thereby turns, the dislodgeable element  60  as a result. While doing so, the front recessed portion  42  pushes the rear recessed portion  51  of the supporting base  50  downward through the dislodgeable element  60  and overcomes the elastic force of the elastic element  52  so that the dislodgeable element  60  can be turned between the front recessed portion  42  and the rear recessed portion  51 . When the dislodgeable element  60  is turned, the front recessed portion  42  is also laterally displaced such that a lateral side of the front recessed portion  42  hits the tube  30 , producing a sound that alerts the user to the fact that a preset torque value is reached. Moreover, while the front recessed portion  42  is turning the dislodgeable element  60 , the relatively short length H of the height  62  renders the distance between the lateral force F generated by the tool head  40  and the center of gravity M of the dislodgeable element  60  relatively short, so it is relatively difficult for the lateral force of the front recessed portion  42  to generate a torque high enough to turn, or rotate, the dislodgeable element  60 . Consequently, the elastic element  52  at the rear end of the supporting base  50  may have a relatively low elastic modulus but is still capable of generating an elastic force great enough to support the supporting base  50 . The relatively low elastic modulus also helps prevent elastic fatigue of the elastic element  52  as may otherwise result from the elastic element  52  generating a much greater elastic force and lead to a reduction in precision of the elastic element  52 . 
     It is worth mentioning that the length L 1  of the widths  611  of the contact surfaces  61  is greater than the lateral dimension of the gap G between the tube  30  and the tool head  40 . Therefore, when the dislodgeable element  60  is turned along the direction of the widths  611  and causes the front recessed portion  42  to hit the tube  30 , the angle through which the dislodgeable element  60  is turned is relatively small, and once the force applied by the user is removed, the dislodgeable element  60  can rapidly return to its original position, allowing the user to resume operation, i.e., to apply a force to the torque wrench  20  again. 
       FIG. 7  shows the dislodgeable element in the second preferred embodiment of the present invention. The second preferred embodiment is structurally the same as the previous embodiment except for the dislodgeable element. The identical structures in the two embodiments are indicated by the same reference numeral and will not be described repeatedly. 
     In the second preferred embodiment, the lengths L 1  and L 2  of the widths  611  and depths  612  of the contact surfaces  61  of the dislodgeable element  60  are not equal. The length L 1  of the widths  611  is greater than the length L 2  of the depths  612 , but both the lengths L 1  and L 2  are greater than the length H of the height  62  of the dislodgeable element  60 . In practice, the length L 2  of the depths  612  may also be less than or equal to the length H of the height  62 , and in that case the dislodgeable element  60  remains difficult to turn. 
     The dislodgement alert structure provided by the present invention includes a dislodgeable element whose widths have a greater length than the height of the dislodgeable element, and which therefore will not be easily turned by the reaction force of the tool head. A conventional dislodgeable element, by contrast, has widths equivalent to its height and requires the use of an elastic element of a relatively high elastic modulus to apply an elastic force to, and thereby push, the dislodgeable element. The dislodgement alert structure of the invention allows the elastic element to have a relatively low elastic modulus, which not only makes it easier to adjust the torque setting, but also contributes to protecting the elastic element from damage, extending the service life of the elastic element, and preventing the torque setting from being affected. 
     The embodiments described above serve only to demonstrate, but not to limit, the technical means of the present invention. All equivalent modifications of the invention shall fall within the scope of the patent protection sought by the applicant. The hand tool disclosed herein has a structure that is the first of its kind in the art. The hand tool also provides an improvement of a practical function. Therefore, a patent application for the invention is hereby filed according to law.