# US 2003/0051385 A1 · Locking hinge > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2003/0051385 A1 - Document ID: US20030051385A1 - Status: Published application - Kind: A1 - Application number: 09/930,626 - Filed: 2001-08-15 - Published: 2003-03-20 - Earliest claimed: 2001-08-15 - Assignees: Blackpoint Engineering, LLC - Inventors: Steven John Wygant - Web page: https://patentgrep.com/patent/US20030051385A1 ## CPC - F41C 23/04: Folding or telescopic stocks or stock parts (articulated or collapsible guns F41A11/04) - F41C: SMALLARMS, e.g. PISTOLS, RIFLES (functional features or details common to both smallarms and ordnance, mountings therefor F41A; projecting missiles without use of explosive or combustible propellant charge F41B); ACCESSORIES THEREFOR ## Abstract A locking hinge especially used in a folding shoulder rest for paintball guns. The locking hinge comprises a first hinge plate and a second hinge plate in relative rotation. The first hinge plate has a hinge joint axis, a plurality of symmetric mounting holes, and a counter bore for receiving the locking mechanism. The counter bore in the first hinge plate contains a spring and a locking cylinder. The locking cylinder has a taper on the end directed toward the second hinge plate. The second hinge plate has a relative hinge joint axis, a plurality of tapered circular cavities or notches, and a means for symmetric mounting. The locking mechanism sufficiently aligns with the tapered circular cavities or notches at plurality of predetermined positions thereby preventing rotation of the hinge plates. A minor misalignment between the locking mechanism and tapered circular cavities further provide rigid locking of the hinge plates. ## Claims ### Claim 1 A locking hinge used in a folding gun stock for a paintball gun, comprising: a first and second hinge plate which are relatively rotatable about a hinge joint axis and a locking means which prevents further relative movement of said first and second hinge plates at a plurality of predetermined positions, said locking means is in the form of a cylinder which the axis of said cylinder is parallel to said hinge joint axis; a hole or notch provided in both said first and second hinge plates receives said locking means thereby preventing the hinge plates from further rotation about said hinge joint at said predetermined positions, which said locking means may lie within or without the periphery of the plates. ### Claim 2 (depends on 1) a hinge as claimed in claim 1, wherein said first hinge plate contains a biasing means and said locking means within a hole thereof ### Claim 3 (depends on 2) a hinge as claimed in claim 2, wherein said biasing means is a compression spring ### Claim 4 (depends on 2) a hinge as claimed in claim 2, wherein said cylinder has a tapered edge and said hole may be a counter bore ### Claim 5 (depends on 1) a hinge as claimed in claim 1, wherein said second hinge plate has a plurality of tapered holes or notches for receiving said cylinder which prevent relative rotation of said first and second hinge plates at a plurality of predetermined positions ### Claim 6 (depends on 1) a hinge as claimed in claim 1, wherein said first and second hinge plates provide a plurality of mounting holes ### Claim 7 (depends on 6) a hinge as claimed in claim 6, wherein the mounting holes are located about a symmetry axis which allows the reverse swing of said locking hinge ### Claim 8 (depends on 7) a hinge as claimed in claim 7, wherein said plurality of holes are counter bored allowing attachment of additional devices to said locking hinge through use of auxiliary mounting holes ### Claim 9 (depends on 1) a hinge as claimed in claim 1, wherein a misalignment of the locking mechanism axis and the receiving hole or notch axis thereby provide rigid locking ### Claim 10 a paintball gun folding shoulder rest using a locking hinge, comprising a locking hinge comprising a first and second hinge plates which are respectively rotatable about a hinge joint and a locking means which prevents further relative movements of said first and second hinge plates at a plurality of predetermined positions, said locking means is in the form of a tapered cylinder moved by a bias means a hole or notch provided in both said first and second hinge plates, which is for receiving said locking means thereby preventing the hinge plates from further rotation about said hinge joint at said plurality of predetermined positions ### Claim 11 (depends on 10) a paintball gun folding shoulder rest as claimed in claim 10, wherein said bias means may be a spring which forces said tapered cylinder toward the second hinge plate at a position in which said locking means will lock said first and second hinge plate at any one of said predetermined positions ### Claim 12 (depends on 10) a paintball gun folding shoulder rest as claimed in claim 10, wherein said locking means has actuation means for selectively releasing said locking means ### Claim 13 (depends on 12) a paintball gun folding shoulder rest as claimed in claim 12, wherein said actuation means is in the form of a push button ### Claim 14 (depends on 13) a paintball gun folding shoulder rest as claimed in claim 13, wherein said push button has a cylindrical shape and a flange ### Claim 15 (depends on 10) a paintball gun folding shoulder rest as claimed in claim 10, wherein said locking means may have a partial engagement to said hole or notch in said first or second hinge plates at said predetermined positions ### Claim 16 (depends on 15) a paintball gun folding shoulder rest as claimed in claim 15, wherein said partial engagement provides direct actuation upon said locking means for disengaging from said predetermined positions thereby providing free rotation of said first and second hinge plate.