A utility knife includes a housing pivotally fixed with a blade holder that can move between a retracted position with the blade holder at least partially contained within the housing, and an extended position. A spring clip spans at least partially across the blade holder and traverses a spring clip slot to engage a notch of a utility blade held within the blade holder. When pressed upwardly, the spring clip clears the notch of the blade, releasing the blade within the blade holder such that the blade can be pulled out of and away from the blade holder. In use, with the blade holder in the retracted position, the blade holder can be moved into the extended position by pressing against the actuator section of the spring clip. The utility knife can be used in this manner with either the left or right hand.

A lockback folding knife having a handle, a blade body pivotally connected in the handle, a constraint member pivotally connected with the handle and having an end abutted with the peripheral edge of the blade body when the blade body is completely stretched out of or received into the handle, a first elastic element having an end fastened in the handle and other end abutted with other end of the constraint member, a locking pin protruded on the constraint member, and a safety switch pivotally connected in the handle and having a locking groove formed thereon corresponding to the locking pin. The locking groove and pin are fastened together when the blade body is completely stretched out of or received into the handle, and the locking groove is escaped from being fastened with the locking pin when the safety switch is applied force.

The present invention relates to a lockback folding knife, which comprises a handle, a blade body pivotally connected in the handle, a constraint member pivotally connected with the handle and having an end abutted with the peripheral edge of the blade body when the blade body is completely stretched out of or received into the handle, a first elastic element having an end fastened in the handle and other end abutted with other end of the constraint member, a locking pin protruded on the constraint member, and a safety switch pivotally connected in the handle and having a locking groove formed thereon corresponding to the locking pin, wherein the locking groove and pin are fastened together when the blade body is completely stretched out of or received into the handle, and the locking groove is escaped from being fastened with the locking pin when the safety switch is applied force.

A folding knife comprises a shank, a blade, a sleeve, a T-shaped lock lever, a cover plate, and an adjusting screw. The shank comprises a left handle and a right handle defining a storage slot. The sleeve has a guide hole and a guide slot. The T-shaped lock lever has a button lever and a guide lever, and the guide lever comprises a first lock catch and a second lock catch. The lock lever is installed in the guide hole. The blade has a lock hole. The cover plate is located on a right side of the right handle and is connected to a right end of the sleeve by adjusting screws.

A self-defense device including a wrist-wearable wearable holder and knife detachably coupled to the wearable holder. The knife includes a handle, body, arm and blade, wherein the handle is coupled to the body and the arm is coupled to the body and blade. The handle, arm and blade are each configured to move relative to the body between retracted and extended positions. The body preferably has a substantially round perimeter and the blade has a substantially curved outer edge matching the curve of the body's perimeter. The handle, arm and blade each substantially retract into the body's round perimeter when in their retracted positions.

A lock is provided for a folding tool including a lock that engages a folding tool in an unfolded, deployed position to prevent unintended folding of the tool. By way of example a tool is provided including: a handle portion; a folding tool portion, where the folding tool portion is configured to be rotatable between a folded, stowed position at least partially within the handle portion, and a deployed position substantially outside of the handle portion; and a locking element, where the locking element is configured to engage a locking surface of the folding tool portion in response to the folding tool portion moving to the deployed position, where the locking element includes an arcuate surface for engaging the locking surface of the folding tool portion.

A self-defense device includes a handle, a body, an arm, and a blade. The handle is coupled to the body. The arm is coupled to the body and to the blade. The handle, the arm, and the blade are each configured to move relative to the body between a retracted position and an extended position. A releasable latch is configured to hold the handle in the retracted position.

A locking structure of folding knife based on an elastic locking plate comprises a knife handle and a blade. The knife handle is provided with an accommodating groove and a locking structure; the locking structure comprises a pivot, an elastic locking plate and an unlocking button. The blade is connected to the pivot, and a guide groove is defined on the pivot; A front end of the elastic locking plate is arranged in the guide groove; the elastic locking plate is provided with a locking part, and the blade is provided with a locking groove; the unlocking button is arranged on the pivot, the unlocking button abuts against one side of the locking plate, and the pivot is provided with an elastic resetting member.

A folding knife assembly includes a handle assembly and a blade member having a primary blade portion with a sharpened cutting edge and a rear portion defining a blade tang. The handle assembly includes a central steel member having a forward tang geometry that is structured and disposed for cooperative, keyed engagement with the opposing blade tang within the handle assembly to effectively achieve a blade tang that extends substantially the length of the handle. A lock pin is movable between a locked position and a release position in relation to a pivot pin to allow pivotal movement of the blade member between the open and closed positions and, together with blade and handle tang geometry, creates a fixed blade to handle structure in the open locked position.

A convenient portable knife includes a knife handle and a cutting blade pivotally connected to the knife handle. The cutting blade has a locking groove. The knife handle is equipped with a swing arm and a locking bolt. The swing arm has a locking portion. The locking portion and locking bolt are located in the locking groove when the cutting blade is in the extended position. The locking bolt can move along the long axis of an elongated hole, allowing the swing arm to smoothly enter and exit the locking groove.