Retractable takedown pin for firearm

A takedown pin assembly for a firearm is disclosed. The takedown pin assembly comprises an elongate pin, a spring, and a head disposed on one end of the pin. The pin further comprises a channel extending along at least a portion of the elongate pin in the direction of the pin's longitudinal axis. The channel has a width sufficient to receive a detent pin from a firearm. The elongate pin is configured to fit within a hole in an upper receiver or lower receiver of a firearm. The head has a lever handle extending laterally from a center portion of the head. A user engages the lever on the head to rotate the pin and allowing the detent pin to travel in the channel. The spring pushes the pin out from the firearm receivers to allow the user to open the action.

FIELD OF THE INVENTION

The invention pertains generally to firearm components and more specifically to a retractable takedown pin for fast disassembly and reassembly of a firearm.

BACKGROUND OF INVENTION

Semi-automatic firearms have been known for a long time. The first semi-automatic rifle was introduced in 1885. The M-16 automatic rifle has been used by the military for years. A civilian version of the M-16 is known as the AR-15 and is a semi-automatic rifle. The AR-15 has been manufactured and sold to civilians for many years. Standard AR-15 semi-automatic rifles are manufactured and distributed with takedown pins. Takedown pins are utilized to secure the upper receiver to the lower receiver. To access the action, a user needs to remove the takedown pin. The user may then separate the lower receiver from the upper receiver. The user can clean the firearm or otherwise access the action. When done the user can then reattach the upper receiver to the lower receiver. The user inserts the takedown pin into the channel to secure the upper receiver to the lower receiver.

Standard takedown pins may be deficient. A detent pin within the body of the receiver may hold a takedown pin in place. However the takedown pin may still be fully removed. This presents an issue if the user misplaces or loses the takedown pin. What is needed is a takedown pin which is specially designed such that it is easy to remove and reinsert and which is not easily fully removed from the firearm.

SUMMARY OF THE INVENTION

The invention is directed toward a takedown pin assembly. The takedown pin assembly comprises an elongate pin having a first end, a second end, and a longitudinal axis extending between the first end and the second end; the elongate pin further comprising a channel within a body of the pin and wherein the channel extends along at least a portion of the elongate pin in the direction of the longitudinal axis; wherein the channel has a width sufficient to receive a detent pin from a firearm; wherein the elongate pin is configured to fit within a hole in an upper receiver or lower receiver of a firearm; a spring having a first end and a second end; a head disposed on the first end of the elongate pin, wherein the head has a lever handle extending laterally from a center portion of the head; and wherein the elongate pin is disposed within a space within the spring.

In another embodiment of the invention, the takedown pin assembly the elongate pin may further comprise a flange disposed at the first end of the elongate pin. The elongate pin may further comprise a protrusion extending from the first end of the elongate pin. The protrusion may extend in the same direction as the longitudinal axis or may extend perpendicular to the longitudinal axis.

The head may further comprise a central recess in the center portion; and one or more cavities disposed in the central recess. The channel of the elongate pin may further comprise a lateral extension disposed at an angle to the longitudinal axis. The channel of the elongate pin may also further comprise a plurality of lateral extensions where each of the plurality of lateral extensions is disposed at an angle to the longitudinal axis. The head may further comprise a central recess having a plurality of cavities disposed radially around a center point in the central recess. In another embodiment, the channel has a first depth at a first point and a second depth at a second point and the first depth and the second depth are not equal.

In another embodiment the invention is directed toward a takedown pin assembly comprising an elongate pin having a first end, a second end, and a longitudinal axis extending between the first end and the second end; wherein the elongate pin further comprises a lever extending laterally from the first end of the elongate pin; a channel within a body of the pin, wherein the channel extends along at least a portion of the elongate pin in the direction of the longitudinal axis; wherein the channel has a width sufficient to receive a detent pin from a firearm; wherein the elongate pin is configured to fit within a hole in an upper receiver or lower receiver of a firearm; and a spring having a first end and a second end.

In another embodiment, the takedown pin assembly comprising an elongate pin having a first end, a second end, and a longitudinal axis extending between the first end and the second end; the elongate pin further comprising a channel within the body of the elongate pin, wherein the channel extends along at least a portion of the elongate pin in the direction of the longitudinal axis and wherein the channel has a width sufficient to receive a detent pin from a firearm; an indentation extending into the elongate pin; wherein the indentation is disposed between the channel and the first end; wherein the indentation extends along at least a second portion of the elongate pin in the same direction as the longitudinal axis; a spring having a first end and a second end; wherein the elongate pin is disposed within a space in the spring; and wherein the elongate pin is configured to fit within a hole in an upper receiver or lower receiver of a firearm. The indentation may have a depth less than a radius of the elongate pin or a depth greater than a radius of the elongate pin.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The claimed subject matter is now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. It may be evident, however, that the claimed subject matter may be practiced with or without any combination of these specific details, without departing from the spirit and scope of this invention and the claims.

The invention is directed toward a takedown pin assembly200. As shown inFIG. 1, the takedown pin assembly200is installed onto a firearm100. The takedown pin assembly200slides into a channel in a firearm100to secure the lower receiver to the upper receiver, as shown inFIG. 1. To remove the upper receiver from the lower receiver the user engages the takedown pin assembly200. The takedown pin assembly200then moves laterally to permit the upper receiver to pivot away from the lower receiver, as illustrated inFIG. 2.

As illustrated inFIG. 3the takedown pin assembly200is configured to fit within the channel102of the firearm100. In the preferred embodiment, the takedown pin assembly200comprises a spring210, a pin220, and a pin head230. As seen inFIG. 4andFIG. 5the preferred structure of the preferred embodiment of the takedown pin assembly200is illustrated. The main component of the pin takedown assembly200is the pin220. The pin220may be any size and shape. In the preferred embodiment the pin220is cylindrical. One end of the pin220is disposed within the head230. The pin220extends from the head230. Disposed on the pin220is a spring210. One end of the spring210engages the head230. The head230may be any size and shape. The spring210may also be any size and shape.

Referring toFIGS. 6A-6D, the preferred embodiment of the pin220is illustrated. The pin220has a shaped groove222. The shaped groove222extends along a portion of the length of the pin220. The shaped groove222may be any size and shape. The shaped groove222is an indentation in the body of the pin220. In another embodiment the pin220may be hollow and the shaped groove222is a shaped aperture in the body of the pin220. In the preferred embodiment the shaped groove222is shaped as a capital letter “T”. The top of the letter “T” is disposed toward the head230. The lower part of the “T” is disposed at the end opposite of the head230. Other shapes may be known for the shaped groove222, such as a straight line, an angled line, an “S” shape, an “L” shape, or any other shape. In some embodiments the pin220may have two or more shaped grooves222. The shaped groove222may have one or more lateral extensions. The main section of the shaped groove222is parallel to the longitudinal axis of the pin220. The lateral extensions may be at any angle to the longitudinal axis. In the preferred embodiment the lateral extension is at a ninety degree angle to the longitudinal axis. In other embodiments the lateral extension of may be at any angle between 1 degree and 179 degrees from the longitudinal axis.

At one end of the pin220is a flange228. The flange228may be any size and shape. The flange228extends radially outward from the pin220. In the preferred embodiment the flange228is a circular extension of the pin220which has a greater diameter than the remainder of the pin220. In other embodiments the flange228may be one or more tabs protruding laterally from the pin220. The flange228is any member or component of the pin220which presents a surface to engage the spring210. In other embodiments there may be an indentation in the pin220to receive the end of the spring210. In other embodiments the spring210may be attached to the pin220by any known means, such as by adhesive or welding.

At the end of the pin220is a protrusion224. The protrusion224may be any size and shape. In the preferred embodiment the protrusion224extends longitudinally from the end of the pin220. The protrusion224is circular but may be other shapes as well. In other embodiments there may be two or more protrusions224. In other embodiments the protrusion224extends radially from the pin220.

Referring toFIGS. 7A and 7B, the preferred embodiment of the head230is illustrated. The head230has a lever236. The lever236permits a user to rotate the pin220along its longitudinal axis. The head230has a central recess232. The central recess232may be any size and shape. The central recess232extends into the body of the head230. At the end of the central recess are a plurality of cavities234. Each cavity234extends into the body of the head230. In the preferred embodiment the cavities234are arranged as a circle. In this embodiment the plurality of cavities234are disposed around a center point in the central recess232. The center point is the center point in the diameter of the circle formed by the plurality of cavities234. In other embodiments there may be only one cavity234. In other embodiments the cavities may be arranged in other shapes. There may be any number of cavities234.

The takedown pin assembly200is configured so that one end of the pin220is disposed within the central recess232of the head. In addition, one end of the spring210is disposed within the central recess232of the head230. In the preferred embodiment the head230rotates freely about the spring210and pin220. The pin220and spring210may press against the internal surface of the central recess232with sufficient friction to prevent the head230from falling off of the pin220. The protrusion224of the pin220is configured to fit within any one cavity234of the head230. The head230may rotate freely about the pin220and the user may press the head230laterally against the pin220so that the protrusion224extends within the first cavity234encountered.

When the takedown pin assembly200is pushed into the firearm100, the free end of the spring210presses against the external surface of the firearm100. The spring210is compressed within the central recess232of the head230. The spring210presses against the flange228of the pin220, pushing the pin220laterally outward from the channel102of the firearm100. The pin220is configured within the firearm such that the detent pin (not shown) within the body of the firearm100extends into the shaped groove222of the pin220. To stay in the locked position the user rotates the head230about its central axis. When this is done the protrusion224is disposed within a cavity234. This causes the pin220to rotate about its central axis. The detent pin then resides within one of the lateral ends of the “T” of the shaped groove222. The spring210presses the pin220laterally outward but the detent pin prevents the lateral movement of the pin220. When the user desires to remove the pin200the user turns the head230by pressing on the lever236. The cavity234of the head230presses against the protrusion224of the pin200, causing the pin220to turn about its axis. When the pin220turns the detent pin is moved out of one of the lateral ends of the “T” into the central axis. When in this position the detent pin no longer prevents the outward movement of the pin220. The spring210pushes against the flange228of the pin to move the pin220out of the channel102of the firearm100. The pin220moves laterally until the detent pin reaches the bottom end of the “T”. The detent pin prevents the pin220from being fully removed from the channel102of the firearm100. The user then may open the action of the firearm. When the user wants to reassemble the firearm100the user reattaches the upper receiver to the lower receiver. The user presses the pin220inward through the channel102. When the pin220is full within the channel102, the user rotates the lever236of the head230. The detent pin is then fully resting within a lateral side of the “T” and the pin220is again locked into place.

The takedown pin assembly200may be made in many configurations. In one embodiment the pin220is utilized only with a spring210without a head230. In another embodiment the pin220and head230are one fused component. In another embodiment the pin220may pass through an aperture in the head230with the flange228extending around the body of the head230. In another embodiment there may be two takedown pin assemblies200used on a single firearm100, with each takedown pin assembly200mounted on opposite sides of the firearm100.

Referring toFIG. 8an alternative embodiment of the takedown pin200is illustrated. In the preferred version of this embodiment the pin220and spring210are utilized without a head230. This embodiment of the pin220is shaped in a different configuration.

Referring toFIGS. 9A-D, the alternative embodiment of the pin220is illustrated. In this embodiment the pin220comprises a shorter shaped groove222. The shaped groove222is disposed on the opposite end from the flange228. In the middle of the length of the pin220is an indentation226. The indentation226may be any size and shape. In the preferred embodiment the indentation226extends over half of the diameter of the pin220. In the preferred embodiment the indentation226has a flat rectangular surface although other shapes may be known.

In the alternative embodiment of the pin220the user inserts the pin220into the channel102. The spring210, if used, is compressed between the flange228and the outside edge of the firearm100. The detent pin is disposed within the shaped groove222. When the user desires to open the action of the firearm the user engages the flange228and the spring pushes the pin220laterally outward. The pin220moves partially from the firearm110. The pin220moves to a point where the indentation226is disposed in the channel102at the point where the outer edge of the upper receiver and the outer edge of the lower receiver are disposed. The thickness of the pin220at the indentation226is less than the diameter of the hole for the pin220in the upper receiver and lower receiver. When the indentation226is disposed at the outer wall of the upper receiver and lower receiver, the upper receiver is may pivot upward so that the bottom of the hole in the upper receiver channel102engages the flat surface of the pin220. In this manner the user may only partially open the action of the firearm100. When the user desires to use the firearm100again the user then closes the upper receiver against the lower receiver and pushes the pin200fully back into the channel102of the firearm100.

Referring toFIGS. 10A-D, an alternative embodiment of the pin220is illustrated. This embodiment of the pin220is similar to the embodiment illustrated inFIGS. 9A-D.

In this embodiment the pin220comprises a special shaped groove222. The shaped groove222is disposed on the opposite end from the flange228. In the middle of the length of the pin220is an indentation226. The indentation226may be any size and shape. In the preferred embodiment the indentation226extends over half of the diameter of the pin220. In the preferred embodiment the indentation226has a flat rectangular surface although other shapes may be known. The special shaped groove222extends along a portion of the pin220in the direction of the longitudinal axis. The special shaped groove222has a portion extending perpendicular to the longitudinal axis of the pin220, forming a “T” and wrapping radially around the pin220. When the shaped groove222reaches the opposite side of the pin220, the shaped groove then turns ninety degrees and extends parallel to the longitudinal axis of the pin220. The shaped groove222then terminates into the second end of the pin220.

This embodiment of the shaped groove222permits a user to completely remove the pin220from the channel102of the firearm100. When fully inserted into the channel102, the detent pin fits within the portion of the shaped groove222which has closed ends along the longitudinal axis. If the user desires, the user can rotate the pin220so that the detent pin travels along the perpendicular portion of the shaped groove222. The detent pin then reaches the portion of the shaped groove222which has an open end at the second end of the pin220, which is opposite from the first end of the pin220with the flange228. The opening at the second end allows the detent pin to be fully removed from the shaped groove222and the pin220can be removed from the channel102of the firearm100.

The separate components of the takedown pin assembly200may be made from any material but are preferably composed of metal. Other components may be utilized in other forms without departing from the scope of the invention. For instance, the spring210is disclosed as a compression spring but other springs may be utilized, such as a torsion spring which causes the pin to rotate about its axis. In another embodiment the spring210is disposed in an internal cavity of the firearm100and pushes the pin220outward from the channel102.