The present invention is to provide a knife, which includes a blade having one end formed as a tip and having an engaging groove formed on a side adjacent to the other end thereof; a handle having a side concavely provided with an inwardly extending receiving space and an engaging post fixedly provided therein adjacent to one end thereof and having an elastic plate provided therein adjacent to the other end thereof; and a back-lock member having a first end corresponding to the receiving space, a second end being movably abutted by a free end of the elastic plate, and a middle section pivotally connected in the handle. Thus, when the second end is being pressed, the other end of the blade can be inserted into the receiving space and, is then securely engaged with the engaging post through the engaging groove while the second end is released.

The present invention is to provide a knife, which includes a blade having one end formed as a tip and having an engaging groove formed on a side adjacent to the other end thereof; a handle having a side concavely provided with an inwardly extending receiving space and an engaging post fixedly provided therein adjacent to one end thereof and having an elastic plate provided therein adjacent to the other end thereof; and a back-lock member having a first end corresponding to the receiving space, a second end being movably abutted by a free end of the elastic plate, and a middle section pivotally connected in the handle. Thus, when the second end is being pressed, the other end of the blade can be inserted into the receiving space and, is then securely engaged with the engaging post through the engaging groove while the second end is released.

A modified blade or knife that fits into a utility knife for cutting metal, wood, carpet and other materials. The blade or knife uses the utility knife body as a handle for easy, quick changing of multiple cutting edges to handle jobs that require a small tool in tight spaces without the need for power. The blades come in many common styles, fine tooth for metal, rough teeth for wood and sharp rounded blades for materials like carpet.

A modified blade or knife that fits into a utility knife for cutting metal, wood, carpet and other materials. The blade or knife uses the utility knife body as a handle for easy, quick changing of multiple cutting edges to handle jobs that require a small tool in tight spaces without the need for power. The blades come in many common styles, fine tooth for metal, rough teeth for wood and sharp rounded blades for materials like carpet.

A knife for holding a blade having a bottom with a hole and a cutting tip which extends from the bottom includes a body having a rest zone for the bottom of the blade to be disposed in the body, and a mouth at a front end of the body which receives the bottom of the blade. The mouth guides the bottom of the blade to the rest zone. The body includes a recess in communication with the rest zone. The knife includes a lock disposed in the recess for securely holding the blade. The lock has a base which is fixedly attached inside the body. When in a locked state, the lock end is disposed in the hole in the bottom of the blade which holds the blade in place and the blade is unable to move from the rest zone. When in an unlocked state, the lock end separate and apart from the hole in the bottom of the blade so the blade can be moved from the rest zone. The lock having a move disposed between the lock end and the base. When a force is applied to the move, the move moves the lock end between the unlocked state and the locked state. Alternatively, there is a jaw with the lock end for the blade. A method for positioning a blade relative to a knife.

The present invention publishes a knife with a replaceable blade, comprising a housing, a cover arranged on the housing and a blade carrier arranged between the housing and the cover, characterized in that, a blade which can move between an extended position and a retracted position is installed on the blade carrier, and a blade cartridge carrier is arrange around the periphery of a position adjacent to the retracted position of the blade, the blade cartridge carrier is provided with an internal space of a blade shape to place spare blades. Wherein, the cover can be connected with the housing in an open type to fix the blade carrier between the cover and the housing.

The present invention publishes a knife with a replaceable blade, comprising a housing, a cover arranged on the housing and a blade carrier arranged between the housing and the cover, characterized in that, a blade which can move between an extended position and a retracted position is installed on the blade carrier, and a blade cartridge carrier is arrange around the periphery of a position adjacent to the retracted position of the blade, the blade cartridge carrier is provided with an internal space of a blade shape to place spare blades. Wherein, the cover can be connected with the housing in an open type to fix the blade carrier between the cover and the housing.

Safety knife with a blade that can be replaced and where access to the cutting edge of the blade is limited so as to reduce the risk of injury to a user, comprising a blade piece with a blade arranged between a guard and a fixation and an oblong knife body comprising a holder and a partly flat insert for rigidly holding the blade piece near a proximal end, wherein said insert having rails on both sides of the flat part at least near the proximal end, said holder including a depression near the proximal end for receiving the fixation and a channel extending from the proximal end towards the distal end at least beyond the depression for receiving at least the flat part of the insert, said channel having grooves on each side starting at the proximal end for receiving the rails.

The present invention provides a utility knife having built in smoothing capabilities, either in the form of a utility knife with a grooved cavity for inserting a removable smoothing element with an abrasive surface, or in the form of a utility knife that has an abrasive surface etched into a portion of the utility knife handle. The invention further provides a smoothing element attachment for retrofitting suitable utility knives.

The present invention provides a utility knife having built in smoothing capabilities, either in the form of a utility knife with a grooved cavity for inserting a removable smoothing element with an abrasive surface, or in the form of a utility knife that has an abrasive surface etched into a portion of the utility knife handle. The invention further provides a smoothing element attachment for retrofitting suitable utility knives.