# US 9,429,388 B2 · Firearm accessory mounting interface > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,429,388 B2 - Document ID: US9429388B2 - Status: Granted - Kind: B2 - Application number: 15/063,396 - Filed: 2016-03-07 - Published: 2016-06-30 - Granted: 2016-08-30 - Earliest claimed: 2014-04-03 - Assignees: Magpul Industries Corp. - Applicants: Magpul Industries Corp. - Inventors: Michael T. Mayberry; William Bradley Bennett; Timothy Eric Roberts; Duane Liptak; Brian L. Nakayama - Web page: https://patentgrep.com/patent/US9429388B2 ## CPC - F41C 27/00: Accessories; Details or attachments not otherwise provided for - F41A 23/08: Bipods - F41C 23/16: Forestocks; Handgrips; Hand guards (pump-action guns F41C7/02) - F41G 1/00: Sighting devices ({structurally associated with laser telemeters F41G3/065;} for indirect laying of fire F41G3/16; bombsights F41G3/24) - F41G 11/001: {Means for mounting sighting or aiming devices on firearms} - F41G 11/003: {Mountings with a dove tail element, e.g. "Picatinny rail systems"} - F41G 11/004: {Mountings with clamping means on the device embracing at least a part of the firearm, e.g. the receiver or a dustcover (F41G11/003 takes precedence)} - F41G 11/005: {Mountings using a pivot point and an anchoring point} - F41C 23/02: Attachment of slings - 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 - F41A: FUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE - F41G: WEAPON SIGHTS; AIMING (optical aspects thereof G02B) ## Abstract An accessory mounting interface for a firearm is provided. The accessory mounting interface has a firearm accessory, a first elongated fastener, a second fastener, and an elongated slot in a firearm. The second fastener has two straight edges parallel to each other, and at least one of the two straight edges prevent the second fastener from rotating beyond a closed position once a portion of the second fastener has passed through and at least partially cleared the elongated slot. ## Claims ### Claim 1 An accessory mounting interface for a firearm, the interface comprising: a firearm accessory having at least one through hole extending from a first surface to a second surface of the firearm accessory; a first elongated fastener arranged through the through hole and having a first end extending below the second surface of the firearm accessory; a second fastener rotationally mated to the first elongated fastener and having a length greater than a width, the length measured along a longitudinal axis of the second fastener, the second fastener comprising a plurality of straight edges; a first slot protrusion, separated into first and second halves surrounding the at least one through hole; and an elongated slot in a firearm, the elongated slot having a length greater than a width, and wherein the width is between the length and width of the second fastener, such that the second fastener can pass through the elongated slot when the longitudinal axis of the second fastener is arranged parallel to a longitudinal axis of the elongated slot, but abuts a sidewall of the elongated slot when the longitudinal axis of the second fastener is arranged obliquely to the longitudinal axis of the elongated slot, wherein at least one of the plurality of straight edges preventing the second fastener from rotating further than a closed position when the at least one of the straight edges abuts the sidewall of the elongated slot. ### Claim 2 (depends on 1) The accessory mounting interface of claim 1, wherein a length of the elongated slot is greater than the length of the first slot protrusion. ### Claim 3 (depends on 2) The accessory mounting interface of claim 2, wherein the length of the elongated slot is sufficient to accommodate two slot protrusions. ### Claim 4 (depends on 3) The accessory mounting interface of claim 3, further comprising a second slot protrusion. ### Claim 5 (depends on 4) The accessory mounting interface of claim 4, wherein the second slot protrusion has a rectangular shape with beveled corners. ### Claim 6 (depends on 5) The accessory mounting interface of claim 5, wherein the second slot protrusion does not surround a through hole. ### Claim 7 (depends on 5) The accessory mounting interface of claim 5, wherein the second slot protrusion surrounds a second through hole. ### Claim 8 (depends on 4) The accessory mounting interface of claim 4, wherein the first slot protrusion fits within the elongated slot and the second slot protrusion fits within a second elongated slot. ### Claim 9 (depends on 1) The accessory mounting interface of claim 1, wherein the elongated slot and the first slot protrusion each have four beveled corners, where a radius of curvature of the beveled corners of the elongated slot is greater than or equal to a radius of curvature of the beveled corners of the slot protrusion. ### Claim 10 (depends on 1) The accessory mounting interface of claim 1, the second fastener having four curved edges, two of them having a first radius of curvature and two of them having a second radius of curvature less than the first radius of curvature and less than or equal to half the width of the elongated slot. ### Claim 11 (depends on 1) The accessory mounting interface of claim 1, wherein the closed position of the second fastener is rotated 45° to 135° from an open position and wherein the longitudinal axis of the second fastener is parallel to the longitudinal axis of the elongated slot when the second fastener is in the open position. ### Claim 12 An accessory mounting interface for a firearm, the interface comprising: a firearm accessory having at least one through hole extending from a first surface to a second surface of the firearm accessory; a first fastener; a second fastener rotationally mated to the first fastener, the second fastener comprising at least one straight edge and first and second curved edges having a first radius and third and fourth curved edges having a second radius greater than the first radius; a first slot protrusion having inner arcs surrounding the through hole, the inner arcs having a radius of curvature greater than or equal to the second radius; and an elongated slot in a firearm, the elongated slot having a length greater than a width, such that the second fastener can pass through the elongated slot when the longitudinal axis of the second fastener is arranged parallel to a longitudinal axis of the elongated slot, but abuts a sidewall of the elongated slot when the longitudinal axis of the second fastener is arranged obliquely to the longitudinal axis of the elongated slot; wherein at least one of the first fastener and the second fastener is arranged through the through hole; the second fastener comprises a closed position and an open position relative to the first fastener, wherein the longitudinal axis of the second fastener is parallel to the longitudinal axis of the elongated slot when the second fastener is in the open position, and the closed position is rotated between 45° and 135° from the open position; and the at least one straight edge prevents the second fastener from rotating further than the closed position when the second fastener abuts the sidewall of the elongated slot. ### Claim 13 (depends on 12) The accessory mounting interface of claim 12, wherein the elongated slot and the first slot protrusion each have four beveled corners, where a radius of curvature of the beveled corners of the elongated slot is greater than or equal to a radius of curvature of the beveled corners of the first slot protrusion. ### Claim 14 (depends on 12) The accessory mounting interface of claim 12, wherein the first radius of curvature of the first and second curved edges is less than half the width of the elongated slot, and the second radius of curvature of the third and fourth curved edges is great than half the width of the elongated slot. ### Claim 15 (depends on 12) The accessory mounting interface of claim 12, wherein the length of the first slot protrusion is such that two slot protrusions will fit within the elongated slot. ### Claim 16 (depends on 15) The accessory mounting interface of claim 15, further comprising a second slot protrusion. ### Claim 17 (depends on 16) The accessory mounting interface of claim 16, wherein the second slot protrusion has a rectangular shape with beveled corners. ### Claim 18 (depends on 17) The accessory mounting interface of claim 17, wherein the second slot protrusion does not surround a through hole. ### Claim 19 (depends on 17) The accessory mounting interface of claim 17, wherein the second slot protrusion surrounds a second through hole. ### Claim 20 (depends on 16) The accessory mounting interface of claim 16, wherein the first slot protrusion fits within the elongated slot and the second slot protrusion fits within a second elongated slot.