Torque wrench

Claim 2

A torque wrench including an elongate, tubular lever arm with front and rear ends, a work-engaging head pivotally carried by the front end of the arm, an elongate compression spring within the arm, trigger means within the arm between the spring and head and normally yieldingly holding the head against pivotal movement relative to the arm, adjusting and setting means in the rear end of the arm and engageable with said spring to vary the effective force of said spring on said trigger means, said adjusting and setting means including a carrier in the arm spaced rearward of the spring, an elongate threaded shaft with front and rear ends threadedly engaged through the carrier, means establishing axial driving engagement between the shaft and the spring, an elongate tube with front and rear ends threadedly engaged on the rear end portion of the shaft and extending longitudinally through the rear end portion of the arm, an elongate tubular sleeve with front and central portions engaged about the tube with its front portion in rotary driving and axially shiftable engagement with said tube and in axially shiftable and rotatable engagement in the rear end portion of the arm and a manually engageable rear end portion accessible at the rear end of the arm, said sleeve being shiftable axially from a normal forward position where its rear portion occurs adjacent the rear end of the arm to an actuated position where its central portion projects rearwardly from the rear end of the arm and releasable lock means to lock the sleeve against rotation relative to the arm when the sleeve is in its normal position and to permit free rotation of the sleeve relative to the arm when the sleeve is in its actuated position.

Claim 3

A structure as set forth in claim 1 wherein said lock means includes a plurality of circumferentially spaced, radially inwardly opening grooves in the rear portion of the arm, an annular, radially outwardly opening race in the rear portion of the central portion of the tube and a radially shiftable drive member carried by the front portion of the sleeve to normally engage the exterior of the tube and project radially outwardly from the sleeve into one of the grooves and to shift radially inwardly to project radially inwardly from the sleeve and into the race when the sleeve is in its actuated position.

Claim 4

A structure as set forth in claim 1 including drag means to frictionally maintain the sleeve in its normal and actuated positions and including an annular radially inwardly opening groove in the front portion of the sleeve, a radially shiftable snapring carried by the groove and yieldingly engaging the tube about the exterior thereof, and retaining means to prevent disengagement of the sleeve and tube and including an annular axially rearwardly disposed stop shoulder in the forward portion of the sleeve and a radially outwardly projecting annular enlargement about the rear portion of the tube to engage and stop against the shoulder when the sleeve is in its actuated position.

Claim 5

A structure as set forth in claim 1 wherein said lock means includes a plurality of circumferentially spaced, radially inwardly opening grooves in the rear portion of the arm, a radially outwardly opening annular race in the rear portion of the central portion of the tube and a radially shiftable drive member carried by the sleeve to normally engage the exterior of the tube and project radially outwardly from the sleeve into one of the grooves and to shift radially inwardly to project radially inwardly from the sleeve and into the race when the sleeve is in its actuated position, drag means to frictionally maintain the sleeve in its normal and actuated positions, and including an annular radially inwardly opening outer groove in the front portion of the sleeve and a radially shiftable snapring carried by the groove and yieldingly engaging the exterior of the tube, and retaining means to prevent disengagement of the sleeve and tube and including an annular axially rearwardly disposed stop shoulder in the forward portion of the sleeve and a radially outwardly projecting annular enlargement about the forward end of the tube to engage and stop against the shoulder when the sleeve is in its actuated position.

Claim 6

A structure as set forth in claim 1 wherein said tube is threadedly engaged on the shaft for longitudinal adjustment relative thereto, said tube carrying means to releasably set the tube against rotation and axial shifting relative to the shaft and including a setscrew in the tube engaging the rear end of the shaft and accessible through the open rear end of the tube.

Claim 7

A structure as set forth in claim 1 wherein said tube is polygonal in cross section and the interior of the front portion of the sleeve is polygonal in cross section and slidably receives the tube, said tube being threadedly engaged on the shaft for longitudinal adjustment relative thereto, said tube carrying means to releasably set the tube against rotation and axial shifting relative to the shaft and including a locking bar in the tube engaging the rear end of the shaft and a setscrew in the tube engaging the rear end of the bar and accessible from the open rear end of the tube.

Claim 8

A structure as set forth in claim 1 wherein said lock means includes a plurality of circumferentially spaced, radially inwardly opening grooves in the rear portion of the arm, an annular radially outwardly opening race in the rear portion of the central portion of the tube and a radially shiftable drive member carried by the sleeve to normally engage the exterior of the tube and project radially outwardly from the sleeve into one of the grooves and to shift radially inwardly to project radially inwardly from the sleeve and into the race when the sleeve is in its actuated position, drag means to frictIonally maintain the sleeve in its normal and actuated positions and including an annular radially inwardly opening groove in the front portion of the sleeve, and a radially shiftable snapring carried by the grooves and yieldingly engaging the exterior of the tube, retaining means to prevent disengagement of the tube and sleeve and including an annular axially rearwardly disposed stop shoulder in the sleeve spaced forward of the rear end thereof and a radially outwardly projecting annular enlargement on the rear end of the tube to engage and stop against the shoulder when the sleeve is in its actuated position, said tube being threadedly engaged on the shaft for longitudinal adjustment relative thereto, said tube carrying means to releasably set the tube against rotation and axial shifting relative to the shaft and including a setscrew in the tube engaging the rear end of the shaft and accessible through the open rear end of the tube.

Claim 9

A torque wrench having an elongate tubular arm with front and rear ends, a work-engaging head pivotally mounted on the front end of the arm, said head having an elongate stem extending longitudinally in the arm, trigger means cooperating with the stem to releasably hold said head and stem against pivotal movement relative to the arm, said trigger means comprising a plunger in the arm spaced rearward of the stem and shiftable axially relative thereto, flat axially spaced seating surfaces on the stem and plunger, an elongate block with flat oppositely disposed bearing surfaces between the stem and plunger with said surfaces normally establishing flat bearing engagement on the seating surfaces, an elongate, axially extending compression spring with front and rear ends in the arm with its front end engaging the plunger to yieldingly urge the plunger forwardly and adjusting means in the arm rearward of the spring to vary and set the force of the spring and including, a carrier in the arm spaced from the rear end thereof, an elongate threaded shaft with front and rear ends threadedly engaged through the carrier, means establishing axial driving engagement between the front end of the shaft and the rear end of the springs, an elongate polygonal tube with front and rear ends threadedly engaged on the rear end of the shaft and extending longitudinally through the rear end portion of the arm, an elongate tubular sleeve with front and central portions, said front portion slidably and rotatably engaged in the rear end portion of the arm, and having a polygonal opening slidably receiving the tube and an enlarged manually engageable rear end portion accessible at the rear end of the arm, said sleeve being shiftable axially from a normal forward position where its central and forward portions occur wholly within the arm and its rear portion occurs adjacent the rear end of the arm to an actuated position where its central portion projects rearwardly from the rear end of the arm and the rear portion is spaced therefrom and lock means carried by the sleeve to releasably lock the sleeve against rotation relative to the arm when the sleeve is in its normal position and to release the sleeve for free rotation relative to the arm, when the sleeve is in its actuated position.

Claim 10

A torque wrench having an elongate tubular arm with front and rear ends, a work-engaging head pivotally mounted on the front end of the arm, said head having an elongate stem extending longitudinally in the arm, trigger means cooperating with the stem to releasably hold said head and stem against pivotal movement relative to the arm, said trigger means comprising a plunger in the arm spaced rearward of the stem and shiftable axially relative thereto, flat axially spaced seating surfaces on the stem and plunger, an elongate block with flat oppositely disposed bearing surfaces between the stem and plunger with said surfaces normally establishing flat bearing engagement on the seating surfaces, an elongate, axially extending compression spring with front and rear ends in the arm with its front end engaging the plunger to yieldingly urge the plunger forwardly and adjusting means in the arm rearward of the spring to vary and set the force of the spring and including, a carrier in the arm spaced from the rear end thereof, an elongate threaded shaft with front and rear ends threadedly engaged through the carrier, means establishing axial driving engagement between the front end of the shaft and the rear end of the springs, an elongate polygonal tube with front and rear ends threadedly engaged on the rear end of the shaft and extending longitudinally through the rear end portion of the arm, an elongate tubular sleeve with front and central portions, said front portion slidably and rotatably engaged in the rear end portion of the arm, and having a polygonal opening slidably receiving the tube and an enlarged manually engageable rear end portion accessible at the rear end of the arm, said sleeve being shiftable axially from a normal forward position where its central and forward portions occur wholly within the arm and its rear portion occurs adjacent the rear end of the arm to an actuated position where its central portion projects rearwardly from the rear end of the arm and the rear portion is spaced therefrom and lock means carried by the sleeve to releasably lock the sleeve against rotation relative to the arm when the sleeve is in its normal position and to release the sleeve for free rotation relative to the arm, when the sleeve is in its actuated position.