Provided is a pair of hairdressing scissors with improved sharpness. The hairdressing scissors include a first scissor member, a second scissor member, and a connecting mechanism including a connecting member. The second scissor member is provided with a long hole relative to which the connecting member moves. Inner hollows of blade body parts are displaced toward the back side at proximal sides of the blade bodies, and curve in parallel with edge lines toward the tips of the blade bodies. Inner hollows of the intermediate parts are provided to pass through the center in the width direction of the intermediate parts. Of the inner hollows of the intermediate parts, contact points are provided at a portion between the inner hollow and the connecting member and at a portion more toward a shank part side relative to the connecting member.

A powered shearing mechanism or cutter is disclosed that comprises an asynchronous double class 1 lever and a linear actuator that uses two ganged wheels to pry the effort portion of both levers open and close the jaws. The wheels move linearly—with the distance between them kept constant—and roll along—and exert force against—parts of the levers called “bearing surfaces.” The bearing surfaces are non-planar and reflectively symmetric and their profile is customized to provide any desired ideal mechanical advantage for the cutter. In accordance with the illustrative embodiment, the profile of the bearing surfaces is a circular arc, which provides a bearing surface which is easy to precisely fabricate and that provides a fairly constant ideal mechanical advantage at each point as the cutter's blades cut through the material.

A powered shearing mechanism or cutter is disclosed that comprises an asynchronous double class 1 lever and a linear actuator that uses two ganged wheels to pry the effort portion of both levers open and close the jaws. The wheels move linearly—with the distance between them kept constant—and roll along—and exert force against—parts of the levers called “bearing surfaces.” The bearing surfaces are non-planar and reflectively symmetric and their profile is customized to provide any desired ideal mechanical advantage for the cutter. In accordance with the illustrative embodiment, the profile of the bearing surfaces is a circular arc, which provides a bearing surface which is easy to precisely fabricate and that provides a fairly constant ideal mechanical advantage at each point as the cutter's blades cut through the material.

One embodiment provides a pair of scissors, including: a first scissor member being pivotally connected to a second scissor member with a joint member at connecting portions; each of the first scissor member and the second scissor member comprising: an upper surface, a lower surface, an inner side, an outer side, a cutting edge on the inner side, a measurement portion positioned on the upper surface abutting the cutting edge and spanning a length thereof, and gripping means; wherein the first scissor member comprises a first integrated comb portion having a first plurality of teeth; wherein the second scissor member comprises a second integrated comb portion having a second plurality of teeth. Other aspects are described and claimed.

A hand-held device includes a first member and a second member coupled together by a pivot point such that each member may rotate independently. The hand-held device further comprises a handle on one side of each member and a protrusion on an opposite side of each member. Further, the hand-held device may include counter-torque extensions which extend from each member such that the counter-torque extensions touch when the device is engaged.

A hand-held device includes a first member and a second member coupled together by a pivot point such that each member may rotate independently. The hand-held device further comprises a handle on one side of each member and a protrusion on an opposite side of each member. Further, the hand-held device may include counter-torque extensions which extend from each member such that the counter-torque extensions touch when the device is engaged.

A hand tool includes a first jaw; a second jaw rotatably coupled to the first jaw, the second jaw including a first set of projections and a first bearing surface, the first bearing surface having a first curvature; and a lever coupled to the first jaw, the lever including a second set of projections and a second bearing surface, the second bearing surface having a second curvature. During a movement of the first and second jaws from a full open position to a full close position, the first and second sets of projections are at least partially engaged to prevent a slippage between the first and second bearing surfaces that are in a rolling contact during the movement of the first and second jaws from the full open position to the full close position.

A hand tool includes a first jaw; a second jaw rotatably coupled to the first jaw, the second jaw including a first set of projections and a first bearing surface, the first bearing surface having a first curvature; and a lever coupled to the first jaw, the lever including a second set of projections and a second bearing surface, the second bearing surface having a second curvature. During a movement of the first and second jaws from a full open position to a full close position, the first and second sets of projections are at least partially engaged to prevent a slippage between the first and second bearing surfaces that are in a rolling contact during the movement of the first and second jaws from the full open position to the full close position.

A composite coating is provided for a tool. The tool can be a pair of scissors or a screwdriver for example. The tool is made with at least one contact face. The composite coating includes diamond grains and layer of metal oxide. The metal oxide is used as an adhesive to secure the diamond grains to the contact face.

A composite coating is provided for a tool. The tool can be a pair of scissors or a screwdriver for example. The tool is made with at least one contact face. The composite coating includes diamond grains and layer of metal oxide. The metal oxide is used as an adhesive to secure the diamond grains to the contact face.