A one-way wrench having a catching device with two catches and a catch holder and having differential teeth is provided and characterized in that: the catching device is disposed in a catching chamber laterally disposed beside a driving hole of the one-way wrench; the catching device has two catches, two position-restoring elements, and a catch holder; the catch holder pushes the two catches simultaneously, such that a single stable base structure pushes the two catches simultaneously; and starting ends of tooth portions of the two catches are dentate to different extents, so as to effectuate a small transmission-oriented tooth-changing angle, achieve stable control, as well as cut production and maintenance costs.

A tool, such as a ratchet tool, including a head portion having a cavity adapted to at least partially enclose a ratchet gear for providing torque to a working piece. Surfaces of the cavity and/or ratchet gear are provided with a compressive residual stress layer by a cold working process, such as, for example, shot peening.

Disclosed are devices, systems and methods for improving medical instruments and related tools, such as a ratcheting module that can be attached to various surgical instruments used during surgery.

A ratchet wrench includes a wrench main body provided at an end thereof with a through hole, wherein a ratchet wheel is disposed, which is provided from top to bottom thereof in order with an upper ratchet portion, an upper annular groove, a middle ratchet portion, a lower annular groove and a lower ratchet portion. The upper and lower ratchet portions both protrude out of the through hole. The middle ratchet portion is located in the through hole. Two retainers are respectively disposed in the upper and lower annular grooves located out of the through hole, for retaining the ratchet wheel in the through hole. As a result, in the ratchet wrench of the present invention, the wrench main body doesn't need much processing, thereby improved in processing convenience. Besides, the installation of the members is convenient and firm, thereby benefiting the operation of the ratchet wheel.

A hand tool includes a body provided with a mounting portion. The mounting portion includes six first recessed portions, six second recessed portions, and six locking faces. Each of the first recessed portions includes two grooves. Each of the second recessed portions includes two first arcuate faces and a second arcuate face. Each of the locking faces has a planar shape and is arranged between two of the second recessed portions. Each of the first recessed portions is arranged on one of the locking faces. The locking faces define an imaginary hexagonal portion having six sides coinciding with the locking faces respectively. The mounting portion of the body is mounted on a screw member. The screw member has six ribs received in the second recessed portions. Each of the ribs rests on one of the first arcuate faces.

A disc brake piston retraction tool includes a reversible ratchet wrench, a first pressure plate assembly, and a second pressure assembly. In the process of retracting a piston, a first engaging notch of a first L-shaped elastic plate of a first buckle member and a second engaging notch of a second L-shaped elastic plate of a second buckle member are pressed against a first force output shaft and a second force output shaft to provide an anti-rotation effect. Thus, when an operating handle of the reversible ratchet wrench is pulled back, it will not link a ratchet wheel, so as to carry out an effective operation of retracting the piston.

A torque wrench includes a handle, a wrench, a clutch, an adjustor, a grip, a scale ring and a locking collar. The wrench includes a lever inserted in and pivotally connected to the handle. The clutch is connected to the lever to stop rotating a workpiece when a maximum value of torque is reached. The adjustor is connected to the clutch and includes a knob operable to adjust the maximum value of torque. The knob is provided with a first color. The grip is connected to the handle. The scale ring is connected to the grip. The locking collar is provided with a second color. The locking collar is movable between a locking position to prevent the knob from rotation relative to the grip and show the first color and an unlocking position to allow the knob to rotate relative to the grip and show the second color.

A ratchet tool that permits a user to selectively determine the direction in which torque is applied to a work piece is disclosed. A rear surface of a pawl creates an instability between a biasing member and the rear surface when the biasing member engages the rear surface at the mid-plane of the pawl. The instability leads to a net force that directs the biasing member and the pawl away from the mid-plane. This arrangement ensures that pawl does not position itself in a central resting position between the sidewalls of a ratchet head.

A torque structure includes a first body provided with a receiving recess, a second body pivotally connected with the first body, a first elastic member received in the second body, a retaining unit including a mounting seat provided with a first threaded portion and a plurality of first through holes, a first adjusting member provided with a head, a positioning seat provided with a plurality of second through holes, and a locking unit including a plurality of first locking members, a second locking member, a plurality of third locking members, a fourth locking member, a fastening member, and a second adjusting member. The fastening member is provided with a fitting portion connected with the first body. The fastening member is provided with a third threaded portion. The second adjusting member is provided with a fourth threaded portion screwed into the third threaded portion.

A torque structure includes a first body set, and a second body set. The second body set has a torque slip function. The second body set includes a second body, a drive head, a resisting module, a plurality of balls, and a mounting ring. The second body is provided with a third receiving recess and a plurality of ball slots. The drive head is connected with the second body. The resisting module is received in the third receiving recess and includes a first abutting element. The mounting ring is mounted on the second body and has an interior provided with a fourth receiving recess. The balls are received in the ball slots and located between the first abutting element and the fourth receiving recess.