Abstract: A knife and sheath combination having an interlock formed of a tab to carry an inwardly extending dog that is mounted on a laterally flexible stem to the sheath. The dog may be moved laterally to and from an interferring engagement with a stop carried on the handle of the knife.

Abstract: A tool and sheath combination in which the tool is securely engaged in the sheath. A release bar having a tip and a distal end is coupled to the sheath. The tool has at least one recess for accepting the tip of the release bar when the tool is fully inserted in the sheath. A flexible element coupled to the release bar biases the release bar to engage the recess when the tool is fully inserted in the sheath and a fulcrum located between the tip and the distal end of the release bar permits rotation of the release bar for disengagement from the recess under finger pressure applied to the distal end. A second surface along the tip and angled obliquely relative to the edge of the recess may continue to engage this edge after the biasing element is overcome by hand pressure to retain the tool in the sheath. This second surface, however, may be overcome by applying force to pull the tool out of the sheath.

Abstract: A knife constructed substantially of plastic and having interchangeable blades removably installed thereon and further having a butt cap disposed on the handle having annular grooves therein for interlockingly engaging O-rings for use in other equipment.

Abstract: A knife and sheath in combination in which a two-headed bolt supported in the knife handle may be positioned to interlock with the sheath. The bolt is symmetrical with respect to the knife to permit insertion of the knife into the sheath in either direction. The sheath has a portion of a resilient flexible wall positioned to engage one head of the bolt to urge the other into a hole in the other side of the sheath to secure the knife within the sheath until the bolt is pushed firmly in the opposite direction to disengage the knife and the sheath.

Abstract: Device for locking a knife having a pommel projecting from the knife handle into a sheath, comprising a rigid ring pivotally supported on the hanger portion of the sheath and adapted to be pivoted from a locking position about the pommel into a non-locking position, in which the ring lies in a plane parallel to the length of the knife when the knife is in the sheath. A leaf spring with one end fixed to the sheath engages a dog projecting from the base of the ring for selectively spring-loading the ring in either a non-locking position or a locking position in which the ring engages the pommel.

Abstract: A knife and sheath combination in which a spring loaded detent projects from the handle of the knife to engage an extension of the sheath whereby the knife is locked into the sheath against inadvertent removal. The knife handle is secured to the knife blade by an assembly that includes the spring loaded detent. The assembly can be removed to separate the handle and the blade for cleaning.