Patent Publication Number: US-2020282533-A1

Title: Torque wrench

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a torque wrench and, more particularly, to a torque wrench permitting easy adjustment of a torque capacity of the torque wrench. 
     Taiwan Patent No. 1647075 discloses a torque wrench including an outer tube having an axially extending compartment; a driving member having a driving head on an end thereof and a connecting end on another end thereof, with the driving member rotatably mounted to an end of the outer tube, with the connecting end extending into the compartment; a pressing member slidably received in the compartment and connected to the connecting end; a sleeve mounted between the outer tube and the pressing member; and a torque adjusting device mounted to another end of the outer tube opposite to the driving member, with the torque adjusting device configured for adjusting a torque value. 
     However, a significant change in the torque value can be achieved when the torque adjusting device undergoes a large rotational movement. In use, the torque adjusting device may have to be rotated one or even several circles to obtain the target torque value, which is troublesome and time-consuming. 
     Thus, a need exists for a novel torque wrench that mitigates and/or obviates the disadvantages of conventional torque wrenches. 
     BRIEF SUMMARY OF THE INVENTION 
     In a first aspect, a torque wrench according to the present invention includes a body, a driving member rotatably mounted in the body, and a torsion control unit. The torsion control unit includes a stopper, a resilient element, and a push rod. The stopper and the resilient element are received in the body. The stopper includes a first end abutting against the driving member and a second end. The resilient element includes a first U-shaped plate having a first end, a second end, and an intermediate portion between the first end and the second end. The intermediate portion is arcuate and is connected to the second end of the stopper. An opening is defined between the first and second ends of the first U-shaped plate of the resilient element and faces away from the stopper. The push rod is connected to the body and has an end simultaneously abutting against the first and second ends of the first U-shaped plate of the resilient element. 
     In an example, the first U-shaped plate of the resilient element is made of a shape memory alloy. 
     In an example, the first U-shaped plate of the resilient element includes an outer, convex surface facing the stopper and an inner, concave surface facing the push rod. The outer, convex surface and the inner, concave surface have a thickness therebetween. The first U-shaped plate of the resilient element includes a first side and a second side opposite to the first side in a diametric direction perpendicular to a longitudinal axis of the push rod. The first side and the second side have a width therebetween. The width is more than two times the thickness. 
     In an example, the driving member includes an outer periphery surrounding a rotating axis of the driving member. A plurality of positioning grooves is defined in the outer periphery of the driving member and is spaced from each other at regular angular intervals. The first end of the stopper includes a positioning protrusion. The positioning protrusion is releasably engaged in one of the plurality of positioning grooves. 
     In an example, the push rod includes a rod body, a push member, and a knob. The rod body is rotatably received in the body and includes a first end having a first threaded portion. The push member has a second threaded portion in threading connection with the first threaded portion. The push member simultaneously abuts against the first and second ends of the first U-shaped plate of the resilient element. The knob is securely connected to a second end of the rod body opposite to the push member, permitting joint rotation of the knob and the rod body. 
     In an example, the body includes a head and a handle. The head includes a rotating groove extending therethrough. The head includes a compartment in a radial direction of the rotating groove. The compartment intercommunicates with the rotating groove and has non-circular cross sections perpendicular to a longitudinal direction of the compartment. The handle has a first end connected to the head and has a through-hole extending from the first end of the handle through a second end of the handle opposite to the first end of the handle. The driving member is received in the rotating groove. The rod body is received in the through-hole. The stopper and the resilient element are received in the compartment. The push member is received in the compartment and has cross sections perpendicular to the longitudinal direction of the compartment. The cross sections of the push member are identical to the non-circular cross sections of the compartment. The knob is located outside of the through-hole of the handle. 
     In an example, the push rod includes a limiting member mounted around the rod body. The limiting member is disposed on a side of the push member opposite to the resilient element. The push rod includes a pivotal seat mounted around the rod body and securely disposed in the through-hole. The rod body further includes a second end opposite to the first end having the first threaded portion. The second end of the rod body has non-circular cross sections. The knob has a non-circular hole coupled with the second end of the rod body. The handle includes an index at the second end thereof opposite to the head. The knob has a scale along an outer periphery thereof around a longitudinal axis of the rod body. The index points to the scale. 
     In an example, the resilient element further includes a second U-shaped plate and a third U-shaped plate. The second U-shaped plate is sandwiched between the first and third U-shaped plates. Each of the second and third U-shaped plates is made of a shape memory alloy and includes first and second ends and an arcuate intermediate portion between the first and second ends. The first and second ends of the second U-shaped plate abut against the first and second ends of the first U-shaped plate. The arcuate intermediate portion of the third U-shaped plate abuts against the arcuate intermediate portion of the second U-shaped plate. 
     In a second aspect, a torque wrench according to the present invention includes a body, a driving member rotatably mounted in the body, and a torsion control unit. The torsional control unit includes a stopper, a resilient element, and a push rod. The stopper and the resilient element are received in the body. The stopper includes a first end abutting against the driving member and a second end. The resilient element includes a plurality of wavy plates each being annular. The plurality of wavy plates is disposed side by side from a position adjacent to the stopper to another position adjacent to the push rod. The plurality of wavy plates is connected to one another. The resilient element has a first end abutting against the second end of the stopper. The push rod is connected to the body and abuts against a second end of the resilient element opposite to the stopper. 
     In an example, the resilient element is made of a shape memory alloy. 
     In an example, the driving member includes an outer periphery surrounding a rotating axis of the driving member. A plurality of positioning grooves is defined in the outer periphery of the driving member and is spaced from each other at regular angular intervals. The first end of the stopper includes a positioning protrusion. The positioning protrusion is releasably engaged in one of the plurality of positioning grooves. 
     In an example, the push rod includes a rod body, a push member, and a knob. The rod body is rotatably received in the body and includes a first end having a first threaded portion. The push member has a second threaded portion in threading connection with the first threaded portion. The push member abuts against the second end of the resilient element. The knob is securely connected to a second end of the rod body opposite to the push member, permitting joint rotation of the knob and the rod body. 
     In an example, the body includes a head and a handle. The head includes a rotating groove extending therethrough. The head includes a compartment in a radial direction of the rotating groove. The compartment intercommunicates with the rotating groove and has non-circular cross sections perpendicular to a longitudinal direction of the compartment. The handle has a first end connected to the head and has a through-hole extending from the first end of the handle through a second end of the handle opposite to the first end of the handle. The driving member is received in the rotating groove. The rod body is received in the through-hole. The stopper and the resilient element are received in the compartment. The push member is received in the compartment and has cross sections perpendicular to the longitudinal direction of the compartment. The cross sections of the push member are identical to the non-circular cross sections of the compartment. The knob is located outside of the through-hole of the handle. 
     In an example, the push rod includes a limiting member mounted around the rod body. The limiting member is disposed on a side of the push member opposite to the resilient element. The push rod includes a pivotal seat mounted around the rod body and securely disposed in the through-hole. The rod body further includes a second end opposite to the first end having the first threaded portion. The second end of the rod body has non-circular cross sections. The knob has a non-circular hole coupled with the second end of the rod body. The handle includes an index at the second end thereof opposite to the head. The knob has a scale along an outer periphery thereof around a longitudinal axis of the rod body. The index points to the scale. 
     In a third aspect, a torque wrench according to the present invention includes a body, a driving member rotatably mounted in the body, and a torsion control unit. The torsion control unit includes a stopper, a resilient element, and a push rod. The stopper and the resilient element are received in the body. The stopper includes a first end abutting against the driving member and a second end. The resilient element is a bowl-shaped member includes a first end connected to the second end of the stopper and an open second end facing away from the stopper. The bowl-shaped member includes a plurality of slits extending from an annular end face of the open second end towards but spaced from the first end of the bowl-shaped member. The push rod is connected to the body and presses against the annular end face of the open second end of the bowl-shaped member. 
     In an example, the resilient element is made of a shape memory alloy. 
     In an example, the driving member includes an outer periphery surrounding a rotating axis of the driving member. A plurality of positioning grooves is defined in the outer periphery of the driving member and is spaced from each other at regular angular intervals. The first end of the stopper includes a positioning protrusion. The positioning protrusion is releasably engaged in one of the plurality of positioning grooves. 
     In an example, the push rod includes a rod body, a push member, and a knob. The rod body is rotatably received in the body and includes a first end having a first threaded portion. The push member has a second threaded portion in threading connection with the first threaded portion. The push member abuts against the second end of the resilient element. The knob is securely connected to a second end of the rod body opposite to the push member, permitting joint rotation of the knob and the rod body. 
     In an example, the body includes a head and a handle. The head includes a rotating groove extending therethrough. The head includes a compartment in a radial direction of the rotating groove. The compartment intercommunicates with the rotating groove and has non-circular cross sections perpendicular to a longitudinal direction of the compartment. The handle has a first end connected to the head and has a through-hole extending from the first end of the handle through a second end of the handle opposite to the first end of the handle. The driving member is received in the rotating groove. The rod body is received in the through-hole. The stopper and the resilient element are received in the compartment. The push member is received in the compartment and has cross sections perpendicular to the longitudinal direction of the compartment. The cross sections of the push member are identical to the non-circular cross sections of the compartment. The knob is located outside of the through-hole of the handle. 
     In an example, the push rod includes a limiting member mounted around the rod body. The limiting member is disposed on a side of the push member opposite to the resilient element. The push rod includes a pivotal seat mounted around the rod body and securely disposed in the through-hole. The rod body further includes a second end opposite to the first end having the first threaded portion. The second end of the rod body has non-circular cross sections. The knob has a non-circular hole coupled with the second end of the rod body. The handle includes an index at the second end thereof opposite to the head. The knob has a scale along an outer periphery thereof around a longitudinal axis of the rod body. The index points to the scale. 
     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 perspective view of a torque wrench of a first embodiment according to the present invention. 
         FIG. 2  is an exploded, perspective view of the torque wrench of  FIG. 1 . 
         FIG. 3  is a cross sectional view of the torque wrench of  FIG. 1 . 
         FIG. 4  is another cross sectional view of the torque wrench of  FIG. 1 . 
         FIG. 5  is a perspective view of a torque wrench of a second embodiment according to the present invention. 
         FIG. 6  is a top view of the torque wrench of  FIG. 5 . 
         FIG. 7  is a perspective view of a torque wrench of a third embodiment according to the present invention. 
         FIG. 8  is a perspective view of a torque wrench of a fourth embodiment according to the present invention. 
         FIG. 9  is an exploded, perspective view of the torque wrench of  FIG. 8 . 
         FIG. 10  is a cross sectional view of the torque wrench of  FIG. 8 . 
         FIG. 11  is an exploded, perspective view of a torque wrench of a fifth embodiment according to the present invention. 
         FIG. 12  is a cross sectional view of the torque wrench of  FIG. 11 . 
         FIG. 13  is an exploded, perspective view of a torque wrench of a sixth embodiment according to the present invention. 
         FIG. 14  is a cross sectional view of the torque wrench of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIGS. 1-4 , a torque wrench  10  of a first embodiment according to the present invention includes a body  20 , a driving member  30 , and a torque control unit  40 . The body  20  includes a head  21  and a handle  22 . The head  21  includes a rotating groove  23  extending therethrough. The head  21  includes a compartment  24  in a radial direction of the rotating groove  23 . The compartment  24  intercommunicates with the rotating groove  23  and has non-circular (elliptic in this embodiment) cross sections perpendicular to a longitudinal direction of the compartment  24 . The handle  22  has a first end connected to the head  21  and has a through-hole  25  extending from the first end of the handle  22  through a second end of the handle  22  opposite to the first end of the handle  22 . The handle  22  includes an index  26  at the second end thereof opposite to the head  21 . 
     The driving member  30  is rotatably mounted in the rotating groove  23  of the body  20 . The driving member  30  includes an outer periphery surrounding a rotating axis of the driving member  30 . A plurality of positioning grooves  31  is defined in the outer periphery of the driving member  30  and is spaced from each other at regular angular intervals. The driving member  30  includes a driving column  32  protruding from a side thereof. The driving column  32  has square cross sections. A driving groove  33  is defined in another side of the driving member  30  opposite to the driving column  32 . The driving groove  33  is hexagonal in cross section. 
     The torsion control unit  40  including a stopper  41 , a resilient element  42 , and a push rod  43 . The stopper  41  and the resilient element  42  are received in the compartment  24  of the body  20 . The stopper  41  includes a first end abutting against the driving member  30  and a second end. The first end of the stopper  41  includes a positioning protrusion  411 . The positioning protrusion  411  is releasably engaged in one of the plurality of positioning grooves  31 . 
     The resilient element  42  includes a first U-shaped plate  420  made of a shape memory alloy. The first U-shaped plate  420  has a first end  421 , a second end  422 , and an intermediate portion  423  between the first end  421  and the second end  422 . The intermediate portion  423  is arcuate and is connected to the second end of the stopper  41 . An opening is defined between the first and second ends  421  and  422  of the first U-shaped plate  420  of the resilient element  42  and faces away from the stopper  41 . 
     The push rod  43  is connected to the body  20  and has an end simultaneously abutting against the first and second ends  421  and  422  of the first U-shaped plate  420  of the resilient element  42 . The first U-shaped plate  420  of the resilient element  42  includes an outer, convex surface  424  facing the stopper  41  and an inner, concave surface  425  facing the push rod  43 . The outer, convex surface  424  and the inner, concave surface  425  have a thickness D therebetween. The first U-shaped plate  420  of the resilient element  42  includes a first side  426  and a second side  427  opposite to the first side  426  in a diametric direction perpendicular to a longitudinal axis of the push rod  43 . The first side  426  and the second side  427  have a width W therebetween. The width W is more than two times the thickness D. 
     The push rod  43  includes a rod body  431 , a push member  432 , and a knob  433 . The rod body  431  is rotatably received in the through-hole  25  of the body  20  and includes a first end having a first threaded portion  434 . The rod body  431  further includes a second end opposite to the first end having the first threaded portion  434 . The second end of the rod body  431  has non-circular cross sections. The push member  432  has a second threaded portion  435  in threading connection with the first threaded portion  434 . The push member  432  is received in the compartment  24  and has non-circular cross sections perpendicular to the longitudinal direction of the compartment  24 . The push member  432  simultaneously abuts against the first and second ends  421  and  422  of the first U-shaped plate  420  of the resilient element  42 . The knob  433  is securely connected to the second end of the rod body  431  opposite to the push member  432 , permitting joint rotation of the knob  433  and the rod body  431 . The knob  433  has a non-circular hole coupled with the second end of the rod body  431  and is located outside of the through-hole  25 . 
     The push rod  43  includes a limiting member  436  mounted around the rod body  431 . The limiting member  436  is disposed on a side of the push member  432  opposite to the resilient element  42 . The push rod  43  includes a pivotal seat  437  mounted around the rod body  431  and securely disposed in the through-hole  25 . The knob  433  has a scale  438  along an outer periphery thereof around a longitudinal axis of the rod body  431 . The index  26  points to the scale  438 . 
     The torque capacity of the torque wrench  10  can be rapidly adjusted by the above structure. In use, the wrench  10  can be used to drive an object through the driving member  30 . When the driving torque is greater than a preset torque value, the resilient element  42  is compressed and deforms, such that the stopper  41  cannot stop the driving member  30 . As a result, the driving member  30  rotates relative to the body  20  but cannot drive the object. When it is desired to adjust the preset torque value, the knob  433  can be rotated to move the push member  432  towards or away from the driving member  30  through the threading connection. The elastic returning force of the resilient element  42  is varied to change the preset torque value of the wrench  10 . Since the resilient element  42  is made of a shape memory alloy in the form of a plate, the adjustment can be rapidly achieved by rotating the knob  433  through a small degree. 
       FIGS. 5 and 6  show a torque wrench of a second embodiment according to the present invention. The second embodiment is substantially the same as the first embodiment except for that the driving member  30   a  includes a driving socket  34   a  protruding from a side thereof. The driving socket  34   a  includes a coupling groove  35   a  in an end face thereof. The coupling groove  35   a  includes an inner periphery having a plurality of protrusions  36   a  and a plurality of grooves  37   a.  The plurality of protrusions  36   a  and the plurality of grooves  37   a,  extend in a longitudinal direction of the coupling groove  35   a,  have the same number, and are alternately disposed. The coupling groove  35   a  includes a bottom wall. A through-hole  38   a  extends through the bottom wall in the longitudinal direction of the coupling groove  35   a  and extends to another side of the driving member  30   a  opposite to the driving socket  34   a.    
       FIG. 7  shows a torque wrench of a third embodiment according to the present invention. The third embodiment is substantially the same as the first embodiment except for that the driving member  30   b  includes a driving socket  34   b  protruding from a side thereof, the driving socket  34   b  includes a coupling groove  35   b  in an end face thereof, and the coupling groove  35   b  is hexagonal in cross section. 
       FIGS. 8-10  show a torque wrench of a fourth embodiment according to the present invention. The fourth embodiment is substantially the same as the first embodiment except for that the resilient element  42   c  is a wavy spring made of a shape memory alloy. The resilient element  42   c  includes a plurality of wavy plates  428   c  each being annular. The plurality of wavy plates  428   c  is disposed side by side from a position adjacent to the stopper  41   c  to another position adjacent to the push rod  43   c.  The plurality of wavy plates  428   c  is connected to one another. The resilient element  42   c  has a first end abutting against the second end of the stopper  41   c.  The push rod  43   c  is connected to the body  20   c  and abuts against a second end of the resilient element  42   c  opposite to the stopper  41   c.  The driving member  30   c  includes a driving column  32   c  protruding from a side thereof. The driving column  32   c  has square cross sections and can provide a ratchet wheel function for driving an object in a single direction. 
       FIGS. 11 and 12  show a torque wrench of a fifth embodiment according to the present invention. The fifth embodiment is substantially the same as the first embodiment except for that the resilient element  42   d  further includes a second U-shaped plate  44   d  and a third U-shaped plate  45   d.  The second U-shaped plate  44   d  is sandwiched between the first U-shaped plate  420   d  and third U-shaped plate  45   d.  Each of the second and third U-shaped plates  44   d  and  45   d  is made of a shape memory alloy and includes first and second ends and an arcuate intermediate portion between the first and second ends. The first and second ends of the second U-shaped plate  44   d  abut against the first and second ends  421  and  422  of the first U-shaped plate  420   d.  The arcuate intermediate portion of the third U-shaped plate  45   d  abuts against the arcuate intermediate portion of the second U-shaped plate  44   d.    
       FIGS. 13 and 14  show a torque wrench of a sixth embodiment according to the present invention. The sixth embodiment is substantially the same as the first embodiment except for that wherein the resilient element  42   e  is a bowl-shaped member made of a shape memory alloy. The bowl-shaped member made includes a first end connected to the second end of the stopper  41   e  and an open second end facing away from the stopper  41 . The bowl-shaped member includes a plurality of slits  429   e  extending from an annular end face of the open second end towards but spaced from the first end of the bowl-shaped member. The push rod  43   e  is connected to the body  20   e  and presses against the annular end face of the open second end of the bowl-shaped member. 
     In view of the foregoing, the torque wrench  10  according to the present invention permits easy adjustment of the torque capacity through simple operation. 
     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.