Patent ID: 8490442

Claim:
An injection molded compact, lightweight polymeric handcuff comprising: a) a strap with a distal end comprising a smooth easy-to-grab region, a central portion having knife grabbing features on the upper surface and a proximal end comprising a head having an aperture; b) said strap head comprising a rectangular deformable portion surrounding said aperture carrying an integrally injection molded steel slanted knife having a sharp knife-edge, said knife having one or more apertures therein for allowing flow thereinto of molten or softened injection molding polymer, thereby creating an integral bond between the knife and the rectangular portion of the head; c) said distal end of said strap, when inserted into said aperture of the head, forming a folded strap and a ring, when inserted nearly at mid point of said folded strap, forming two loops for placing the hands of a prisoner therethrough; d) said knife grabbing features comprising a plurality of hillocks separated by valleys present along the full length on the upper surface of the strap, and said knife-edge interfering with said knife grabbing features when inserted into aperture of said head; e) said slanted knife-edge being operative to clear said knife grabbing features of hillocks by elastic deformation of said rectangular portion of the head when said strap is pulled through the aperture to secure said handcuff and restrain the prisoner; f) said knife-edge landing in the valley between hillocks assisted by the release of elastic deformation of the rectangular portion of the head when the handcuff is tightened on the prisoner's wrists; g) attempts by the prisoner to release the handcuff by pulling, twisting or wiggling the handcuff being operative to dig the knife edge into an adjacent hillock, thereby locking the handcuff against movement of the strap through the aperture; and h) said strap being provided with a pair of gussets operative to prevent twisting of said head or knife-edge; whereby the handcuff securely constrains the prisoner at the selected location and does not over tighten to constrict blood supply to the prisoner's hands.