A quick-release device for screwdriver bit includes a shank having a polygonal hole longitudinally defined in one end thereof and adapted for partially receiving a bit. At least one slot is longitudinally defined in the shank. An annular groove is defined in an inner periphery of the polygonal hole and communicates with the at least one slot, wherein the annular groove is formed with a tapered section toward the first end of the shank. An expandable limit element is received in the annular groove. A sleeve is movably sleeved on the shank. The sleeve has at least one protrusion inwardly extending therefrom and engaged into the at least one slot and abutting against the limit element when removing the bit form the polygonal hole. A stopper is secured on one end of the shank for preventing the sleeve from removing from the shank.

Devices, systems and methods for holding devices, including tool holders and/or associated apparatus, that can be attached to various driving mechanisms. Various embodiments can include one or more canted, or slanted, coil springs that are capable of forming to various shapes by the application of a controlled force.

Devices, systems and methods for holding devices, including tool holders and/or associated apparatus, that can be attached to various driving mechanisms. Various embodiments can include one or more canted, or slanted, coil springs that are capable of forming to various shapes by the application of a controlled force.

Devices, systems and methods for holding devices, including tool holders and/or associated apparatus, that can be attached to various driving mechanisms. Various embodiments can include one or more canted, or slanted, coil springs that are capable of forming to various shapes by the application of a controlled force.

A fastener driving tool includes a shaft with a working region disposed at a first end of the shaft and configured to drive a fastener, a shank portion disposed proximate a second end of the shaft and configured to couple the shaft to a power tool, and a reduced diameter torsion zone disposed between the shank portion and the working region, the torsion zone extending from a first shoulder closer to the working region to a second shoulder closer to the shank portion. A length (L) and a radius (c) of the torsion zone have been optimized so that approximately half of breakages occur in the working region and approximately half of breakages occur in the torsion zone.

A bit holder assembly for a rotary hand or powered tool, includes a body having a hex shank at its rearward end and a retraction collar slidably disposed on the body. The body has a coaxial hex socket formed therein to allow a tool bit to be inserted thereinto. A coil spring biases the retraction collar forwardly and biases a retaining clip toward the bottom of an angular slot formed in the body. The bit is removed by sliding the retraction collar rearwardly, to compress the coil spring and allow the retaining clip to retract back up the slot. A ring magnet is disposed at the forward end of the retraction collar to magnetize a fastener to retain the fastener to the bit.

A quick-release device for screwdriver bit includes a shank having a polygonal hole longitudinally defined in one end thereof and adapted for partially receiving a bit. At least one slot is longitudinally defined in the shank. An annular groove is defined in an inner periphery of the polygonal hole and communicates with the at least one slot, wherein the annular groove is formed with a tapered section toward the first end of the shank. An expandable limit element is received in the annular groove. A sleeve is movably sleeved on the shank. The sleeve has at least one protrusion inwardly extending therefrom and engaged into the at least one slot and abutting against the limit element when removing the bit form the polygonal hole. A stopper is secured on one end of the shank for preventing the sleeve from removing from the shank.

A fastener driving tool includes a shaft with a working region disposed at a first end of the shaft and configured to drive a fastener, a shank portion disposed proximate a second end of the shaft and configured to couple the shaft to a power tool, and a reduced diameter torsion zone disposed between the shank portion and the working region, the torsion zone extending from a first shoulder closer to the working region to a second shoulder closer to the shank portion. A length (L) and a radius (c) of the torsion zone have been optimized so that approximately half of breakages occur in the working region and approximately half of breakages occur in the torsion zone.