Patent EP-4066999-A1 (EP)
Inventor: WEI KAIXUAN
IPC: B25B23/142
Filed: 2021-03-31
Abstract: In a first aspect, the present invention discloses a torque wrench for applying torque to fasteners, said torque wrench comprising a fastener drive structure having a head constructed and arranged to be removably engaged with a fastener and tang structure extending rearwardly from said head. The torque wrench further includes a wrench body including a casing structure, said fastener drive structure and said casing structure being pivotally connected for pivotal movement relative to one another about a pivot axis (A) from a normal position to a torque exceeded position to generate a torque exceeded signal. The torque wrench also includes a tang engaging and stabilizing structure having a tilt block and a pusher, and wherein said tilt block includes a forward end and a rearward end, and wherein when said casing structure is in its normal position, the tang engaging surface flushly engages a rear end portion of the tang, and the pusher engaging surface flushly engages the pusher, and wherein when said casing structure is in its torque exceeded position, an edge of the tilt block that is adjacent the tang engaging surface engages the rear end portion of the tang, and another edge of the tilt block adjacent the pusher engaging surface engages the pusher. The torque wrench also includes a stressed biasing element applying a biasing force to said tang engaging and stabilizing structure such that, during a torque applying operation wherein a force applied to said wrench body (a) is transmitted as torque to a fastener removably engaged with said head and (b) tends to pivot said casing structure relative so said fastener drive structure about said pivot axis, the biasing force applied by said biasing element maintains the tang engaging and stabilizing structure in engagement with said tang structure rear end portion so as to maintain said casing structure and said fastener drive structure in said normal position thereof until a torsional resistance offered by the fastener reaches a threshold level determined by the biasing force of said biasing element whereat the force being applied to said wrench body pivots said casing structure relative to said fastener drive structure to said torque exceeded position to generate the torque exceeded signal, thus indicating that the torsional resistance being offered by the fastener has reached the threshold level. The torque wrench further includes an adjuster constructed and arranged such that rotational movement thereof adjusts the stress in said biasing element and hence the biasing force applied to said tang engaging and stabilizing structure by said biasing element so as to set the aforesaid threshold level of torsional resistance at which the force being applied to said wrench body pivots said casing structure relative to said fastener drive structure as aforesaid. The torque wrench is characterized in that the adjuster comprises an adjustment shaft having a threaded portion, a splined portion, and a pin retaining portion. The adjuster also includes a handle insert having an outer surface shaped to define one or more gears, and an inner opening that is shaped to receive the splined portion of the adjustment shaft, and wherein the surface of said inner opening includes one or more splines configured to mate with the splines the adjustment shaft such that rotation of the handle insert will impart rotation to the adjustment shaft. The adjuster further includes a handle having an interior recess configured to receive the handle insert, and wherein said recess is positioned within the handle such that at least one gear of the outer surface of the handle insert is in a 12 o'clock orientation within the handle and wherein when said handle insert is disposed in the recess, rotational movement of handle will impart rotational force to the handle insert and subsequently to the adjustment shaft. The adjuster further includes an adjusting nut defining an opening having a threaded surface that is configured to mate with the threaded portion of the adjustment shaft, and wherein when rotational force is applied to the adjustment shaft, the mating threaded portions impart translational movement to the adjusting nut, which adjusts a thrust bearing and apply biasing force of the biasing element.