# US 2014/0196338 A1 · Hinge Pin Connector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196338 A1 - Document ID: US20140196338A1 - Status: Published application - Kind: A1 - Application number: 14/153,981 - Filed: 2014-01-13 - Published: 2014-07-17 - Earliest claimed: 2013-01-11 - Assignees: Sig Sauer, Inc. - Applicants: Sig Sauer, Inc. - Inventors: Ethan Lessard - Web page: https://patentgrep.com/patent/US20140196338A1 ## CPC - F41A 3/66: Breech housings or frames; Receivers - F41A 35/02: Dust- or weather-protection caps or covers (protecting-caps for trigger guards F41A17/54) - Y10T 29/49826: Assembling or joining - F41A: FUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Improvements and modifications in the rifle and submachine gun platforms to improve accuracy, improve user functionality, simplify and improve the machining and manufacturing and assembly process are presented. Specifically, the disclosure describes a hinge pin connection system for an access door, a retention mechanism that eliminates freedom of movement for hand guards, cuts in a barrel extension that reduce or eliminate barrel rotation, a barrel retention mechanism that allows for securing of a barrel from the sides of a firearm, a dove tail connection between an up rod and bolt carrier, and an aperture located on a lower receiver for mounting slings and other accessories. ## Claims ### Claim 1 An integral hinge pin connector for a firearm, the hinge pin connector comprising: a substantially horizontal shelf member extending from an outer surface of a firearm receiver; a containing member extending downwardly from the outer surface of the receiver to define a longitudinal slot between the containing member and the receiver surface, the slot aligned with the axis of the firearm and having a cross dimension in at least one direction that is approximately equal to the diameter of a hinge pin to be secured in the connector; and wherein the shelf member, the containing member, and the surface of the receiver are configured to retain an ejection port hinge pin in a substantially horizontal position. ### Claim 2 (depends on 1) The integral hinge pin connector of claim 1 wherein the shelf member is forward of the containing member. ### Claim 3 (depends on 1) The integral hinge pin connector of claim 1 wherein the slot is bounded by an upper surface defined by the containing member, the upper surface positioned above the substantially horizontal surface of the shelf member by a dimension approximately equal to the diameter of the hinge pin. ### Claim 4 (depends on 1) The hinge pin connector of claim 1 further comprising a forward assist assembly or a shell deflector wherein the forward assist assembly or shell deflector defines a cavity for receiving an end of the hinge pin. ### Claim 5 (depends on 1) The hinge pin connector of claim 1 wherein the hinge pin connector is forward of the ejection port. ### Claim 6 (depends on 1) The hinge pin connector of claim 1 wherein the shelf member is located directly above a barrel clamp. ### Claim 7 (depends on 4) The hinge pin connector of claim 4 wherein the hinge pin is secured by three points of contact including the shelf member, the containing member and either the forward assist assembly or the shell deflector. ### Claim 8 A method of retaining a hinge pin in a firearm, the method comprising: placing a first end of the hinge pin in a bore positioned behind an ejection port; pivoting a second end of the hinge pin upwardly; pushing the second end of the hinge pin under a containing member that is integral to the firearm; and securing the pin against three points of contact including the bore, the containing member and a shelf member that is integral to the firearm receiver. ### Claim 9 (depends on 8) The method of claim 8 further comprising threading the hinge pin through a knuckle of an ejection port cover prior to pushing the second end of the hinge pin under the containing member. ### Claim 10 (depends on 8) The method of claim 8 further comprising removing the ejection port cover by pulling the second end of the hinge pin out from the containing member to disconnect the hinge pin and ejection port cover assembly from the firearm. ### Claim 11 (depends on 8) The method of claim 8 comprising shifting the hinge pin forward after pushing the hinge pin under the containing member. ### Claim 12 A method of securing a hinge pin to a firearm, the method comprising: sliding a first end of a hinge pin axially into a receiving cavity between a shelf member and a containing member wherein the receiving cavity, shelf member and containing member are all integral to the firearm receiver; pivoting the second end of the hinge pin upwardly while the first end is supported by the shelf member; and moving the hinge pin into a slot behind the containing member until the axis of the hinge pin is aligned with the axis of the firearm. ### Claim 13 (depends on 12) The method of claim 12 comprising passing the hinge pin through a hinge knuckle on an ejection port cover prior to pivoting the hinge pin upwardly. ### Claim 14 (depends on 12) The method of claim 12 further comprising removing the hinge pin by pulling the second end of the hinge pin downwardly until the hinge pin clears the containing member. ### Claim 15 (depends on 12) The method of claim 12 further comprising aligning the second end of the hinge pin with a bore in either the shell deflector or the forward assist assembly of the firearm. ### Claim 16 (depends on 12) The method of claim 12 wherein the hinge pin is prevented from moving axially and rotationally by being in contact with the shelf member, the containing member and the side of the upper receiver.