Security sheath for knives

A knife-and-sheath combination comprising:

• (a) a sheath having two opposite walls formed of a substantially rigid yet resilient plastic thermoformable resin material,
• (b) a knife having a knife blade and handle, said blade being inserted between said opposite walls of said sheath,
• (c) said walls of said sheath being securely fastened together along at least two edges of each wall,
• (d) said opposite walls being heat molded to conform to at least a substantial portion of the knife blade and a portion of the handle such that the two walls of the sheath grip the knife sufficiently tightly to retain and prevent separation of said knife from said sheath when said sheath is in an inverted position,
• (e) said walls of the sheath being secured substantially at a lower end to a generally rectangular semi-rigid, substantially flat member adapted to be inserted into a pocket of an item of dress worn upon a user such that the knife and sheath are maintained in an inverted position and the flat member extends substantially parallel to one of said opposite sheath walls along at least a portion of the sheath, and
• (f) wherein the generally rectangular semirigid member is of a size to bulk stabilize such rectangular semirigid member in said pocket.

A knife sheath adapted for securely gripping a knife having a hilt and a knife blade to prevent non-voluntary separation of said knife from within said sheath, said sheath comprising:

• (a) two opposite walls formed of a substantially rigid yet resilient plastic resin material, said sheath walls being arranged and constructed such that said walls are adapted to encompass said knife blade therebetween,
• (b) said opposite sheath walls being secured together along substantially intersecting edges,
• (c) said opposite sheath walls being heat molded to conform to at least a substantial portion of said knife blade such that the sheath is adapted to grip said knife blade inserted thereinto sufficiently tightly to retain said knife and prevent gravitationally-induced separation, if the sheath is oriented in an inverted position, and
• (d) a resilient gripping arrangement on said sheath and being adapted for secondary resilient contact with said hilt of said knife when inserted into the sheath,
• (e) means for supporting said sheath on a user, said means for supporting being attached to said sheath and
• (f) wherein said resilient gripping arrangement is a resiliently biased extension on the sheath adapted to contact the hilt of the knife when said knife is inserted into said sheath, said extension being formed from a portion of one of said opposite sheath walls and including an S-shaped curved portion molded therein, wherein said curved portion is positioned adjacent said supporting means and biases said hilt away from said supporting means.