A cutter comprising two members each having a handle portion and an operative portion. The two members are pivoted together at a pivot located between the handle portion and the operative portion of each of the said two members so that the members are movable relative to one another about the pivot. The cutter further comprises at least one releasable cutter blade on the operative portion of one of the said two members. The two members are pivoted together releasably about a pivot pin of the pivot. The or each cutter blade is formed with an aperture through which extends the pivot pin.

A hand-held drive cleat cutter-notcher for the cutting and/or notching of sheet materials, particularly drive cleats. The device in one example: a first handle; a second handle pivotably coupled to the first handle at a handle pivot; the handle pivot having a handle pivot axis; an inner jaw coupled to the first handle; the inner jaw comprising an inner jaw cutting edge substantially triangular in cross section in a plane parallel to the handle pivot axis; an outer jaw coupled to the second handle, the outer jaw having an insert surface beveled in a plane orthogonal to a cutting plane orthogonal to the pivot plane and orthogonal to the handle pivot; the outer jaw having a surface defining an outer jaw cutting edge adjacent which the inner jaw cutting edge passes; and wherein rotation of the second handle relative to the first handle rotates the inner jaw relative to the outer cutting jaw.

An attachment device for use with a hand tool having a handle portion with a distal end includes a connection member having a connection point, and a receiver coupled to and extending axially from the connection member to define a central channel having an open end. The receiver is configured to receive at least a portion of the handle portion within the central channel via the open end. The receiver is configured to permit the insertion of the handle portion into the central channel while restricting the removal of the handle portion therefrom.

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 first handle coupled to a second jaw, the second jaw pivotably coupled to the first jaw and having a first geared structure, the first geared structure including a first plurality of teeth and a first bearing surface; and, a second handle coupled to a lever, the lever pivotably coupled to the first jaw and including a second geared structure, the second geared structure including a second plurality of teeth and a second bearing surface, wherein the first and second handles are movable between a full open position and a full close position such that during movement from the full open position to the full close position, the first plurality of teeth are at least partially engaged with the second plurality of teeth and the first and second bearing surfaces are in rolling contact.

A shears that includes a first cutting blade including a first aperture and a second cutting blade including a second aperture, the second cutting blade pivotally coupled to the first cutting blade at a pivot joint. The shears further includes a first handle operable to pivot the first cutting blade about the pivot joint and a second handle operable to pivot the second cutting blade about the pivot joint. The pivot joint includes a bolt that extends through the first aperture and the second aperture. The bolt includes a head, a shank that extends from the head, and a longitudinal axis that extends centrally through the head and the shank along a length of the shank. The head includes a concave outer surface that extends around the longitudinal axis of the bolt.

A hand tool or plier including a plurality of lever arms, a number of jaws, a cam assembly and a cam follower. The plier tool provides efficient and comfortable transfer of energy from the human hand to the plier tool by utilizing an lever arm and at least part of the cam to generate a transformational increase in mechanical advantage and allow maximum amount of power to be derived from a hand squeezing action, and to do so with a minimum discomfort and strain to the hand because the strongest part of the hand squeezes the handles portions with the greatest travel.

Hand tools which have an ergonomic using a palm handle and finger handle designs which achieve mechanical efficiency and ease of use. The ergonomic handle is compatible with the muscle movements of an operator using a hand tool reducing muscle strain and pain. Optionally, the palm and finger handles can have ergonomically designed cushions. In an embodiment, the finger handle can have a finger set which has a forward finger flange, a tail finger flange and a pinky grip. The ergonomic handle can also use a relief washer system to achieve a smooth low frictional resistance cutting stroke.

An attachment device for use with a hand tool having a handle portion with a distal end includes a connection member having a connection point, and a receiver coupled to and extending axially from the connection member to define a central channel having an open end. The receiver is configured to receive at least a portion of the handle portion within the central channel via the open end. The receiver is configured to permit the insertion of the handle portion into the central channel while restricting the removal of the handle portion therefrom.

A cutting device for a bone fixing plate having a multipurpose bite for easily bending bone in the shape of a hook while reducing the size of a fixing plate for fixing fractured bone to each other. Curved surface cutting and V-shape cutting can be performed using one cutting device, thereby reducing the number of equipment, shortening surgery time, and generating a strong holding force at the time of bending to enable precise cutting.