Locking takedown pin

Abstract

A Locking Takedown Pin includes an outer pin and an inner pin. The outer pin has a slot and ball bearing pockets. The inner pin has a threaded and non-threaded section, an anti-rotate pin hole, bearing loading recesses, and wedge-shaped profiles. A knob rotates on the outer pin and is threaded onto the inner pin. An anti-rotate pin is inserted into the anti-rotate pin hole of the inner pin and slides in the slot of the outer pin such that the inner pin cannot rotate with respect to the outer pin. Ball bearings in the ball bearing pockets may protrude outside the outer pin but may not fully pass through the ball bearing pockets. The wedge-shaped profiles selectively position the ball bearings in a protruding position or in a withdrawn position as the inner pin translates axially within the outer pin upon rotation of the knob.

Description

Locking Takedown PinBACKGROUNDField of Invention0001] Embodiments described herein generally relate to a Locking Takedown Pin for securely joining together the upper and lower receivers of an AR-15 style rifle. The Locking Takedown Pin replaces the front and rear solid pins that ordinarily hold the receivers together.Related Art

[0002] The Upper and Lower receivers of AR-15 style rifles are joined by a pair of pins, commonly referred to as takedown pins, that retain the receivers to one another. There is an inherent amount of clearance between the pin holes and pins to allow for assembly of the firearm. Often, this clearance is excessive, either as originally manufactured or as a result of wear. This results in an ongoing problem with the loose takedown pins resulting in a sloppy fit between the upper and lower receivers. Not only does this result in poor performance of the firearm in terms of reliable operation and accuracy, but it also results in an annoying rattle when carrying and shooting the rifle. Moreover, in a combat situation a firearm that rattles in this way could compromise a combatant's location and movements.

[0003] Many different designs are known to have been utilized in order to do away with the movement between the upper and lower receivers in order to reduce this problem. Some, such as the Accu Wedge available from Arms Unlimited of 20161 Pabco Road, Henderson, Nevada 89011 are effective to reduce the ra ttle and play between the upper and lower receivers. However, designs of this type make the rifle hard to open and actually force the receiver surfaces away from one another. Oversized pins are also available. However, these are limited in their effectiveness due to the variation in rifle component tolerance and wear.

[0004] Accordingly, there is an unmet need for a Locking Takedown Pin for connecting together the upper and lower receivers of an AR-15 style rifle while reducing the play therebetween and without increasing the difficulty of operating the rifle or reducing its accuracy.SUMMARY

[0005] Embodiments of the Locking Takedown Pin disclosed herein solve the problem of excessive clearance between the upper and lower receivers of any brand of AR-15 style rifle that results in inaccuracy, unreliability, and rattling, while requiring no modification of the rifle itself. This present Locking Takedown Pin replaces the front and rear solid pins that hold the receivers together as providedby the firearm manufacturer. The wedge action of the Locking Takedown Pin disclosed herein removes the clearance between the receivers by pulling together and tightly clamping the upper receiver against the lower receiver in such a way that the mating surfaces of the upper and lower receivers are placed into full contact. Specifically, embodiments of the Locking Takedown Pin adjust so that force is exerted primarily upon the upper receiver lugs in a direction toward the lower receiver, so that the mating surfaces are pulled tightly together without interference from the lower receiver. This results in the rifle feeling more stable, increased accuracy, and reduced rattling noises.

[0006] This accomplished without increasing the difficulty of operating the rifle or forcing the receiver surfaces away from one another. This allows the rifle to be opened, operated, and carried as intended while improving accuracy, reliability, and stability. Moreover, the Locking Takedown Pin disclosed herein achieves a great foundation or bedding for rifle harmonics to perform properly. The Locking Takedown Pin according to the present disclosure allows the rifle to be smoothly and easily opened for cleaning and for clearing of jams by removing the rear such pin and swinging the lower receiver away from the upper receiver. Due to the use of ball bearings in the design of the Locking Takedown Pin, rotational friction is minimized even when appropriately tightened, and there is typically no need to readjust the pin when closing the rifle. Only if wear has increased and the mating surfaces between the upper and lower receivers are no longer being held tightly does the Locking Takedown Pin need to be adjusted. Embodiments of the Locking Takedown Pin according to the present disclosure can take up to fifteen thousandths of an inch of play out of the interface between the upper and lower receiver, although it is contemplated that more or less adjustment may be provided.

[0007] Embodiments of the Locking Takedown Pin according to the present disclosure are further designed to minimize bulkiness in order to avoid catching on clothing and gear. Embodiments of the Locking Takedown Pin are applicable to one of the most widely used types of firearms used by civilian, police, and military personnel around the world. Both the overall outside pin dimensions and the resultant play between the upper and lower receivers comply with military specification tolerances. Embodiments of the Locking Takedown Pin according to the present disclosure include a sliding keyway with detent holes that allow the Locking Takedown Pin to be withdrawn from engagement while preventing the Locking Takedown Pin from being inadvertently removed from the rifle and lost.

[0008] All of this and more is accomplished using an inner pin and outer pin arrangement wherein the inner pin is provided with ramp or wedge-shaped recesses. Ball bearings are provided and positioned within the ramp or wedge-shaped recesses and protrude through openings in the outer pin. The inner pin is translated axially within the outer pin using a threaded knob that is held in rotational relationshipwith the outer pin using a dovetail arrangement. As the inner pin moves axially, the ramp or wedge shape moves in relation to the ball bearings, thereby displacing the ball bearings so that they protrude through the openings in the outer pin to a greater or lesser degree. The threaded knob is provided with knurling as well as detents so that the adjustment remains the same when the lower receiver is rotated with respect to the upper receiver and so that the threaded knob will not loosen due to vibration.0009] Advantageously, if the inner pin, the bearings, the knob, or the detents of the Locking Takedown Pin fail in any way, the Locking Takedown Pin will still operate to retain the lower receiver to the upper receiver. Moreover, the inner pin, the threaded knob, the ramp or wedge-shaped recesses, and the ball bearings provide sufficient mating force that, if a Locking Takedown Pin is used in both the front and rear positions, and if the inner pin, the bearings, the knob, or the detents of one Locking Takedown Pin fail in any way, the remaining operational Locking Takedown Pin will still hold the upper and lower receiver tightly together. In this way, stronger mating between the upper receiver and the lower receiver is provided resulting in better accuracy, and the rifle will not fail due to a faulty Locking Takedown Pin, which may be critical in military applications.

[0010] In an alternative hydraulic embodiment of the Locking Takedown Pin, the inner pin is replaced with a piston having a threaded piston rod. The bearings are replaced with displaceable members such as pistons oriented perpendicular to the long axis of the Locking Takedown Pin. In this way, when the piston having a threaded piston rod is displaced by the threaded knob, hydraulic force is transmitted from the piston having a threaded piston rod to the pistons oriented perpendicular to the long axis of the Locking Takedown Pin. The pistons oriented perpendicular to the long axis of the Locking Takedown Pin then exert force against the upper receiver lug, thereby pulling the upper and lower receivers together similarly to the embodiments of the Locking Takedown Pin described previously.

[0011] According to one embodiment of the invention, an embodiment of the Locking Takedown Pin includes an outer pin having an anti-rotate slot, at least one ball bearing pocket, and a head. The Locking Takedown Pin further includes an inner pin having a threaded section, a cylindrical section, an anti-rotate pin hole, at least one bearing loading recess, and at least one ramp or wedge-shaped profile. A knob is rotatably engaged with the head of the outer pin and threadably engaged with the threaded section of the inner pin. An anti-rotate pin is inserted into the anti-rotate pin hole of the inner pin and slidably engaged with the anti-rotate slot of the outer pin such that the inner pin is prevented from rotating with respect to the outer pin. At least one ball bearing is engaged with the at least one ball bearing pocket such that the at least one ball bearing may protrude outside the outer pin but may not fully pass through the at least one ball bearing pocket. The at least one ramp or wedge-shaped profile isconfigured to selectively position the at least one ball bearing in a protruding position or in a withdrawn position as the inner pin translates axially within the outer pin upon rotation of the knob.

[0012] According to another embodiment of the invention, a rifle includes an embodiment of the Locking Takedown Pin. The rifle has an upper receiver having at least one upper receiver lug and an upper receiver mating surface. The rifle further has a lower receiver having at least one lower receiver lug and a lower receiver mating surface. The Locking Takedown Pin includes an outer pin having an anti - rotate slot, at least one ball bearing pocket, and a head. The Locking Takedown Pin further includes an inner pin having a threaded section, a cylindrical section, an anti-rotate pin hole, at least one bearing loading recess, and at least one ramp or wedge-shaped profile. A knob is rotatably engaged with the head of the outer pin and threadably engaged with the threaded section of the inner pin. An anti-rotate pin is inserted into the anti-rotate pin hole of the inner pin and slidably engaged with the anti-rotate slot of the outer pin such that the inner pin is prevented from rotating with respect to the outer pin. At least one ball bearing is engaged with the at least one ball bearing pocket such that the at least one ball bearing may protrude outside the outer pin but may not fully pass through the at least one ball bearing pocket. The at least one ramp or wedge-shaped profile is configured to selectively position the at least one ball bearing in a protruding position or in a withdrawn position as the inner pin translates axially within the outer pin upon rotation of the knob. The Locking Takedown Pin is inserted into the at least one lower receiver lug and into the at least one upper receiver lug such that the at least one lower receiver lug and the at least one upper receiver lug hold the lower receiver mating surface against the upper receiver mating surface.

[0013] According to another embodiment of the invention, a method for manufacturing a rifle having a Locking Takedown Pin includes several steps. The first step is providing an upper receiver with at least one upper receiver lug and an upper receiver mating surface. The second step is providing a lower receiver with at least one lower receiver lug and a lower receiver mating surface. The third step is providing the Locking Takedown Pin with an outer pin having an anti-rotate slot, at least one ball bearing pocket, and a head. The fourth step is providing the Locking Takedown Pin with an inner pin having a threaded section, a cylindrical section, an anti-rotate pin hole, at least one bearing loading recess, and at least one ramp or wedge-shaped profile. The fifth step is rotatably engaging a knob with the head of the outer pin and threadably engaged the knob with the threaded section of the inner pin. The sixth step is inserting an anti-rotate pin into the anti-rotate pin hole of the inner pin and slidably engaging the anti¬ rotate pin with the anti-rotate slot of the outer pin such that the inner pin is prevented from rotating with respect to the outer pin. The seventh step is engaging at least one ball bearing with the at leastone ball bearing pocket such that the at least one ball bearing may protrude outside the outer pin but may not fully pass through the at least one ball bearing pocket. The eighth step is configuring the at least one ramp or wedge-shaped profile to selectively position the at least one ball bearing in a protruding position and in a withdrawn position as the inner pin translates axially within the outer pin upon rotation of the knob. The ninth step is inserting the Locking Takedown Pin into the at least one lower receiver lug and into the at least one upper receiver lug such that the at least one lower receiver lug and the at least one upper receiver lug hold the lower receiver mating surface against the upper receiver mating surface.DESCRIPTION OF THE DRAWINGS0014] The above-mentioned and other features of embodiments of the Locking Takedown Pin, and the manner of their working, will become more apparent and will be better understood by reference to the following description of embodiments of the Locking Takedown Pin taken in conjunction with the accompanying drawings, wherein:

[0015] Figs. 1A and IB are side views of an upper receiver and a lower receiver of a rifle having an embodiment of a Locking Takedown Pin, as described herein;

[0016] Figs. 2A and 2B are partial section views of an upper receiver and a lower receiver of a rifle having an embodiment of a Locking Takedown Pin, as described herein;

[0017] Figs. 3A and 3B are detail section views of an embodiment of a Locking Takedown Pin, as described herein;

[0018] Figs. 4A and 4B are perspective views of an upper receiver and a lower receiver of a rifle having an embodiment of a Locking Takedown Pin, as described herein;

[0019] Figs. 5A and 5B are exploded perspective views of an embodiment of a Locking Takedown Pin, as described herein;

[0020] Figs. 6A and 6B are exploded side views of an embodiment of a Locking Takedown Pin, as described herein;

[0021] Fig. 7 is a partial side view of an upper receiver and a lower receiver of a rifle in a closed position and having an embodiment of a Locking Takedown Pin, as described herein;

[0022] Fig. 8 is a partial side view of an upper receiver and a lower receiver of a rifle in an open position and having an embodiment of a Locking Takedown Pin, as described herein;

[0023] Figs. 9A, 9B, and 9C are partial bottom views of an upper receiver and a lower receiver of a rifle having an embodiment of a Locking Takedown Pin, as described herein;0024] Fig. 10 is a side view of an embodiment of a Locking Takedown Pin, as described herein;

[0025] Fig. 11 is a side view of an embodiment of a Locking Takedown Pin. as described herein;

[0026] Fig. 12 is a partial perspective view of an embodiment of a Locking Takedown Pin, as described herein;

[0027] Fig. 13 is a perspective view of an embodiment of a Locking Takedown Pin, as described herein; and,

[0028] Fig. 14 is a partial bottom view of an upper receiver and of a lower receiver of a rifle placed side by side, as described herein.

[0029] Corresponding reference numbers indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the BLAH, and such exemplifications are not to be construed as limiting the scope of the claims in any manner.DETAILED DESCRIPTION

[0030] Referring now to Figs. 1A and IB, side views of a rifle 10 having an upper receiver 70 and a lower receiver 80 is shown. Figs. 4A and 4B are perspective views thereof. An embodiment of the Locking Takedown Pin 12 is shown installed in place of the front and rear takedown pins. Figs. 2A and 2B, show partial section views of the Locking Takedown Pins 12 installed on the rifle 10 in the front location and in the rear location respectively. Each Locking Takedown Pin 12 engages the upper receiver 70 by way of the upper receiver lug 74 and engages the lower receiver 80 by way of the lower receiver lugs 84. Each Locking Takedown Pin 12 includes an outer pin 40 and an inner pin 20 disposed within the outer pin 40. The inner pin 20 is able to translate axially within the outer pin 40 but is prevented from rotating within the outer pin 40 by an anti-rotate pin 100 that is inserted into an inner pin anti-rotate pin hole 22 within one end of the inner pin 20. The anti-rotate pin 100 engages an outer pin anti-rotate slot 42 in the same end of the outer pin 40, which allows the inner pin 20 to translate axially within the outer pin 40 but only over a certain distance, and which prevents the inner pin 20 from coming out of the outer pin 40 completely.

[0031] The inner pin 20 is provided with an inner pin threaded section 24 and an inner pin cylindrical section 26. The outer pin 40 is provided with an outer pin head 54 having an outer pin head dovetail recess 58. A knob 90 has a knob dovetail 92 that engages the outer pin head dovetail recess 58 and allows the knob 90 to rotate while remaining fixed in position with respect to the longitudinal axis of the outer pin 40. The knob 90 is threadably engaged with the inner pin threaded section 24 so that when the knob 90 is rotated, the inner pin 20 forcibly translates axially within the outer pin 40.0032] Meanwhile, ball bearings 110 are positioned within outer pin ball bearing pockets 48 that extend through the lower part of the outer pin 40. The outer pin ball bearing pockets 48 are sized so that the ball bearings 110 may protrude outside of the diameter of the outer pin 40 but cannot pass entirely through the outer pin ball bearing pockets 48. The inner pin 20 is provided with inner pin ramp or wedge-shaped profiles 30 located above the outer pin ball bearing pockets 48. The inner pin ramp or wedge-shaped profiles 30 are configured so that when the knob 90 is turned so that the inner pin 20 translates axially within the outer pin 40 towards the outer pin head 54, the ball bearings 110 are forced radially outwards.

[0033] In order to initially load the ball bearings 110 into the space between the inner pin ramp or wedge-shaped profiles 30 and the outer pin ball bearing pockets 48, inner pin bearing loading recesses 28 are provided at the end of the inner pin ramp or wedge-shaped profiles 30 closest to the inner pin threaded section 24 and the outer pin head 54. Prior to installation of the anti-rotate pin 100, the inner pin 20 is rotated so that the inner pin bearing loading recesses 28 are positioned beneath outer pin ball bearing loading holes 46, and the ball bearings 110 are loaded into the inner pin bearing loading recesses 28. The inner pin 20 is again rotated so that the ball bearings 110 drop into the outer pin ball bearing pockets 48. The inner pin is then positioned so that the anti-rotate pin 100 can be inserted through the outer pin anti-rotate slot 42 into the inner pin anti-rotate pin hole 22. The locations of the outer pin anti-rotate slot 42 and the inner pin anti-rotate pin hole 22 are such that the ball bearings 110 are captured between the inner pin ramp or wedge-shaped profiles 30 and the outer pin ball bearing pockets 48 over the full length of travel of the anti-rotate pin 100.

[0034] As noted previously, each Locking Takedown Pin 12 engages the upper receiver 70 by way of the upper receiver lug 74 and engages the lower receiver 80 by way of the lower receiver lugs 84. The ball bearings 110 and the outer pin ball bearing pockets 48 are situated along the bottom of the Locking Takedown Pin 12 within the upper receiver lug 74. As wear accumulates within the bores of the upper receiver lug 74 and lower receiver lugs 84, or simply due to excessive tolerance within said bores, the operator simply twists the knob 90. This forcibly moves the inner pin 20 in the direction of the knob 90 and outer pin head 54 by way of the inner pin threaded section 24 being threadably engaged with the knob 90 and the inner pin 20 being prevented from rotating by the anti-rotate pin 100 and outer pin anti-rotate slot 42. The inner pin ramp or wedge-shaped profiles 30 then cooperate with the outer pin ball bearing pockets 48 to forcibly push the ball bearings 110 radially outward.

[0035] When this happens, the Locking Takedown Pin 12 is forced upward within the bore of the upper receiver lug 74 and the lower receiver lugs 84 are pulled upwards, thereby pulling the lower receiver 80into tight engagement with the upper receiver 70. To facilitate greater upwards movement of the Locking Takedown Pin 12 within the bore of the upper receiver lug 74 when the bore is otherwise worn or has too great of tolerance, the outer pin 40 is provided with an outer pin chordal flat 44. The outer pin chordal flat 44 also facilitates machining of the outer pin ball bearing loading holes 46 and the outer pin ball bearing pockets 48. As shown in Figs. 3A and 3B, to prevent loosening, the outer pin head 54 is provided with an outer pin head detent bore 60 having a pin locking detent ball 120 and a pin locking detent spring 122. The pin locking detent spring 122 forces the pin locking detent ball 120 into engagement with knob detent notches 94 on the underside of the knob 90, thereby preventing unwanted turning of the knob 90 due to vibration.

[0036] Figs. 5A and 6A show an exploded perspective view and an exploded side view, respectively, of an embodiment of the Locking Takedown Pin 12 adapted for use in the forward takedown pin position of an AR-15 type rifle. Figs. 5B and 6B show an exploded perspective view and an exploded side view, respectively, of an embodiment of the Locking Takedown Pin 12 adapted for use in the rearward takedown pin position of an AR-15 type rifle. As before, each Locking Takedown Pin 12 includes an outer pin 40 and an inner pin 20 that is able to translate axially within the outer pin 40. An anti-rotate pin 100 is inserted through an outer pin anti-rotate slot 42 into an inner pin anti-rotate pin hole 22 in order to allow the inner pin 20 to translate axially within the outer pin 40 over a fixed distance while preventing the inner pin 20 from rotating within the outer pin 40.

[0037] The inner pin 20 is again provided with an inner pin threaded section 24 and an inner pin cylindrical section 26. The outer pin 40 is again provided with an outer pin head 54 having an outer pin head dovetail recess 58. A knob 90 again has a knob dovetail 92 that engages the outer pin head dovetail recess 58 and allows the knob 90 to rotate while remaining fixed in position with respect to the longitudinal axis of the outer pin 40. The knob 90 is again threadably engaged with the inner pin threaded section 24 so that when the knob 90 is rotated, the inner pin 20 forcibly translates axially within the outer pin 40.

[0038] Outer pin ball bearing loading holes 46 are again provided in the outer pin 40, by way of which ball bearings 110 may be loaded into inner pin bearing loading recesses 28 prior to installation of the anti-rotate pin 100. The inner pin 20 is again rotated so that the ball bearings 110 drop into outer pin ball bearing pockets 48. The outer pin ball bearing pockets 48 are again sized so that the ball bearings 110 may protrude outside of the diameter of the outer pin 40 but cannot pass entirely through the outer pin ball bearing pockets 48. The inner pin is then positioned so that the anti-rotate pin 100 can be inserted through the outer pin anti-rotate slot 42 into the inner pin anti-rotate pin hole 22,0039] The inner pin 20 is again provided with inner pin ramp or wedge-shaped profiles 30 located above the outer pin ball bearing pockets 48. The inner pin ramp or wedge-shaped profiles 30 are again configured so that when the knob 90 is turned so that the inner pin 20 translates axially within the outer pin 40 towards the outer pin head 54, the ball bearings 110 are forced radially outwards. The locations of the outer pin anti-rotate slot 42 and the inner pin anti-rotate pin hole 22 are again such that the ball bearings 110 are captured between the inner pin ramp or wedge-shaped profiles 30 and the outer pin ball bearing pockets 48 over the full length of travel of the anti-rotate pin 100.

[0040] As before, in order to facilitate greater upwards movement of the Locking Takedown Pin 12 within the bore of the upper receiver lug (not shown), the outer pin 40 is provided with an outer pin chordal flat 44. To prevent loosening of the knob 90, the outer pin head 54 is again provided with an outer pin head detent bore 60 having a pin locking detent ball 120 and a pin locking detent spring 122. The pin locking detent spring 122 forces the pin locking detent ball 120 into engagement with knob detent notches 94 on the underside of the knob 90, thereby preventing unwanted turning of the knob 90 due to vibration. The knob 90 is further provided with knob knurling 96 to facilitate turning of the knob 90.

[0041] The outer pin 40 is provided with an outer pin sliding keyway 50 that cooperates with a detent in the rifle (not shown) to retain the outer pin 40 in the rifle and to prevent the outer pin 40 from turning within the lower receiver lugs 84 and upper receiver lug 74. Where necessary for clearance purposes, an outer pin head chordal flat 56 may be present in the outer pin head 54, whereupon, the outer pin sliding keyway 50 may or may not extend into the outer pin head chordal flat 56 as geometrically necessary. The outer pin sliding keyway 50 may be provided with outer pin sliding keyway detent holes 52, which may further cooperate with a spring ball type detent in the rifle (not shown) to selectively retain the Locking Takedown Pin 12 in the withdrawn and inserted positions.

[0042] Turning now to Fig. 7, a partial side view of a rifle 10 is shown having an upper receiver 70 and a lower receiver 80. A Locking Takedown Pin 12 is shown installed in the forward position on the rifle 10, thereby connecting the upper receiver lug (not shown) with the lower receiver lugs 84. The upper receiver 70 is provided with an upper receiver mating surface 72 and the lower receiver 80 is provided with a lower receiver mating surface 82. The Locking Takedown Pin 12 functions to pull and hold the upper receiver mating surface 72 into tight contact with the lower receiver mating surface 82 by way of tension on the upper receiver lug and lower receiver lugs. The Locking Takedown Pin 12 is provided with a knob 90 allowing operation of the Locking Takedown Pin 12 as described above.0043] Fig. 8 shows a partial view of the rifle 10 is shown having the upper receiver 70 with the upper receiver mating surface 72 and the lower receiver 80 with the lower receiver mating surface 82. A Locking Takedown Pin 12 is shown installed in the forward position on the rifle 10, thereby connecting the upper receiver lug (rear upper receiver lug 74 shown) with the lower receiver lugs 84. The rifle 10 is shown with the lower receiver 80 rotated about the Locking Takedown Pin 12 down and away from the upper receiver 70. The Locking Takedown Pin 12 is provided with a knob 90 allowing operation of the Locking Takedown Pin 12 as described above. Because of the design of the Locking Takedown Pin 12 utilizing ball bearings, rotation of the lower receiver 80 about the Locking Takedown Pin 12 down and away from the upper receiver 70 is smooth and simple, and requires no further adjustment of the Locking Takedown Pin 12.

[0044] Turning now to Figs. 9A, 9B, and 9C, partial bottom views of a rifle 10 are shown. In Fig. 9A, the lower receiver 80 is fully engaged with the upper receiver 70 so that the lower receiver lugs 84 are aligned with the upper receiver lug 74, and the Locking Takedown Pin 12 is inserted therethrough. The Locking Takedown Pin 12 is inserted completely, so that the outer pin head 54 is adjacent to the lower receiver lug 84. In Fig. 9B, the Locking Takedown Pin 12 has been removed entirely, and the lower receiver 80 has been rotated away from the upper receiver 70, so that the lower receiver lugs 84 are no longer aligned with the upper receiver lug 74. The Locking Takedown Pin 12 is shown having the outer pin 40 and the outer pin head 54. Ball bearings 110 can be seen through the outer pin ball bearing pockets 48 in the outer pin 40. The Locking Takedown Pin 12 is again provided with the knob 90 and knob knurling 96, so that the Locking Takedown Pin 12 may be operated as previously described.

[0045] In Fig. 9C, the Locking Takedown Pin 12 is illustratively shown positioned inserted into the lower receiver lugs 84 of the rifle 10, while the lower receiver 80 has again been rotated away from the upper receiver 70, so that the lower receiver lugs 84 are no longer aligned with the upper receiver lug 74. In this way, Fig. 9C shows the position and orientation of the outer pin ball bearing pockets 48 and ball bearings 110 of the Locking Takedown Pin 12 relative to the upper receiver lug 74. Specifically, with the outer pin head 54 positioned adjacent to the lower receiver lug 84, both sets of outer pin ball bearing pockets 48 in the outer pin 40, and the ball bearings 110, are aligned with the upper receiver lug 74. As a result, when the Locking Takedown Pin 12 is inserted through the lower receiver lugs 84 and through the upper receiver lug 74 when the lower receiver 80 is fully engaged with the upper receiver 70, and when the knob 90 with its knob knurling 96 is rotated so that the ball bearings 110 protrude through the outer pin ball bearing pockets 48, the upper receiver lug 74 is pulled downward, thereby pulling the lower receiver 80 into tight engagement with the upper receiver 70.

[0046] Figs. 10 and 11 show an embodiment of the Locking Takedown Pin 12 having an inner pin 20 and an outer pin 40. The outer pin 40 is again provided with an outer pin head 54 and an outer pin chordal fiat 44, the function of which has been described previously. The outer pin 40 is further provided with an outer pin sliding keyway 50 with outer pin sliding keyway detent holes 52 that again cooperates with a detent in the rifle (not shown) to retain the Locking Takedown Pin 12 in the rifle and to prevent the outer pin 40 from turning within the upper and lower receiver lugs (not shown). When the knob 90 with its knob knurling 96 is turned, the inner pin 20 again forcibly translates axially within the outer pin 40 as a result of its threaded engagement with the knob 90. The inner pin 20 is again provided with inner pin ramp or wedge-shaped profiles (not shown) located above outer pin ball bearing pockets (not shown) that are again configured so that when the knob 90 is turned, for example clockwise, the ball bearings 110 are forced radially outwards as shown in Fig. 10. When the knob 90 is turned, for example counterclockwise, the ball bearings 110 retract inwards within the outer pin ball bearing pockets as shown in Fig. 11.

[0047] Figs. 12 and 13 show another embodiment of the Locking Takedown Pin 12. The embodiment of the Locking Takedown Pin 12 shown in Figs. 12 and 13 is again provided with an outer pin 40 and an inner pin 20 that is able to translate axially within the outer pin 40. An anti-rotate pin 100 is again inserted through an outer pin anti-rotate slot 42 into an inner pin anti-rotate pin hole 22 in order to allow the inner pin 20 to translate axially within the outer pin 40 while preventing the inner pin 20 from rotating within the outer pin 40. Outer pin ball bearing loading holes 46 are again provided in the outer pin 40, by way of which ball bearings 110 may be loaded into inner pin bearing loading recesses 28 prior to installation of the anti-rotate pin 100. The inner pin 20 is again provided with an inner pin threaded section (not shown) and an inner pin cylindrical section 26. The outer pin 40 is again provided with an outer pin head 54. A knob 90 with knob knurling 96 is again threadably engaged with the inner pin threaded section 24 so that when the knob 90 is rotated, the inner pin 20 forcibly translates axially within the outer pin 40.

[0048] The inner pin 20 is again provided with inner pin ramp or wedge-shaped profiles 30 located above outer pin ball bearing pockets (not shown). As before, in order to facilitate greater upwards movement of the Locking Takedown Pin 12 within the bore of the upper receiver lug (not shown), the outer pin 40 is provided with an outer pin chordal flat 44. The outer pin 40 is provided with an outer pin sliding keyway 50 that cooperates with a detent in the rifle (not shown) to retain the outer pin 40 in the rifle and to prevent the outer pin 40 from turning within the lower receiver lugs 84 and upper receiver lug 74. Where necessary for clearance purposes, an outer pin head chordal flat 56 may be present inthe outer pin head 54, whereupon, the outer pin sliding keyway 50 may or may not extend into the outer pin head chordal flat 56 as geometrically necessary. The outer pin sliding keyway 50 may be provided with outer pin sliding keyway detent holes (not shown), which may further cooperate with a spring ball type detent in the rifle (not shown) to selectively retain the Locking Takedown Pin 12 in the withdrawn and inserted positions.0049] Fig. 14 shows a rifle 10 including the upper receiver 70 and the lower receiver 80 positioned next to each other in order to show the upper receiver mating surface 72 and the lower receiver mating surface 82. Upper receiver lug 74 is positioned on the upper receiver 70 near the upper receiver mating surface 72 and lower receiver lugs 84 are positioned on the lower receiver 80 near the lower receiver mating surface 82. In this way, when the upper receiver 70 is positioned against the lower receiver 80 and an embodiment of the Locking Takedown Pin (not shown) is inserted through the lower receiver lugs 84 and the upper receiver lug 74, the upper receiver mating surface 72 and the lower receiver mating surface 82 are held tightly together.

[0050] While the Locking Takedown Pin has been described with respect to at least one embodiment, the Locking Takedown Pin can be further modified within the spirit and scope of this disclosure, as demonstrated previously. This application is therefore intended to cover any variations, uses, or adaptations of the Locking Takedown Pin using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which the disclosure pertains and which fall within the limits of the appended claims.REFERENCE NUMBER LISTING10 Rifle 70 Upper receiver12 Locking Takedown Pin 72 Upper receiver mating surface 74 Upper receiver lug20 Inner pin22 Inner pin anti-rotate pin hole 80 Lower receiver24 Inner pin threaded section 82 Lower receiver mating surface 26 Inner pin cylindrical section 84 Lower receiver lugs28 Inner pin bearing loading recesses30 Inner pin wedge-shaped profile 90 Knob92 Knob dovetail40 Outer pin 94 Knob detent notches 42 Outer pin anti-rotate slot 96 Knob knurling44 Outer pin chordal flat46 Outer pin ball bearing loading holes 100 Anti-rotate pin48 Outer pin ball bearing pockets50 Outer pin sliding keyway 110 Ball bearings52 Outer pin sliding keyway detent holes54 Outer pin head 120 Pin locking detent ball 56 Outer pin head chordal flat 122 Pin locking detent spring 58 Outer pin head dovetail recess60 Outer pin head detent bore

Claims

WHAT IS CLAIMED IS:

1. A Locking Takedown Pin, comprising:an outer pin having an anti-rotate slot, at least one ball bearing pocket, and a head;an inner pin having a threaded section, a cylindrical section, an anti-rotate pin hole, at least one bearing loading recess, and at least one ramp or wedge-shaped profile;a knob rotatably engaged with the head of the outer pin and threadably engaged with the threaded section of the inner pin;an anti-rotate pin inserted into the anti-rotate pin hole of the inner pin and slidably engaged with the anti-rotate slot of the outer pin such that the inner pin is prevented from rotating with respect to the outer pin; andat least one ball bearing engaged with the at least one ball bearing pocket such that the at least one ball bearing may protrude outside the outer pin but may not fully pass through the at least one ball bearing pocket; whereinthe at least one ramp or wedge-shaped profile being configured to selectively position the at least one ball bearing in a protruding position and in a withdrawn position as the inner pin translates axially within the outer pin upon rotation of the knob.

2. The Locking Takedown Pin of claim 1, wherein:the outer pin is provided with a chordal flat positioned opposite the at least one ball bearing pocket.

3. The Locking Takedown Pin of claim 2, wherein:the outer pin is further provided with at least one ball bearing loading hole positioned within the chordal flat.

4. The Locking Takedown Pin of claim 1, wherein:the outer pin is provided with at least one sliding keyway having at least one detent hole.

5. The Locking Takedown Pin of claim 1, wherein:the head of the outer pin being provided with a dovetail recess and the knob being provided with a dovetail rotatably engaged with the dovetail recess of the head of the outer pin.

6. The Locking Takedown Pin of claim 5, wherein:the head of the outer pin being provided with a detent bore and the knob being provided with detent notches; whereina detent ball and a detent spring is positioned within the detent bore and the detent ball is engaged with the detent notches to affect an incremental rotation of the knob relative to the outer pin.

7. A rifle having a Locking Takedown Pin, comprising:an upper receiver having at least one upper receiver lug and an upper receiver mating surface: a lower receiver having at least one lower receiver lug and a lower receiver mating surface; wherein the Locking Takedown Pin is provided with:an outer pin having an anti-rotate slot, at least one ball bearing pocket, and a head; an inner pin having a threaded section, a cylindrical section, an anti-rotate pin hole, at least one bearing loading recess, and at least one ramp or wedge-shaped profile;a knob rotatably engaged with the head of the outer pin and threadably engaged with the threaded section of the inner pin:an anti-rotate pin inserted into the anti-rotate pin hole of the inner pin and slidably engaged with the anti-rotate slot of the outer pin such that the inner pin is prevented from rotating with respect to the outer pin; and at least one ball bearing engaged with the at least one ball bearing pocket such that the at least one ball bearing may protrude outside the outer pin but may not fully pass through the at least one ball bearing pocket; wherein the at least one ramp or wedge-shaped profile being configured to selectively position the at least one ball bearing in a protruding position and in a withdrawn position as the inner pin translates axially within the outer pin upon rotation of the knob; whereinthe Locking Takedown Pin is inserted into the at least one lower receiver lug and into the at least one upper receiver lug such that the at least one lower receiver lug and the at least one upper receiver lug hold the lower receiver mating surface against the upper receiver mating surface.

8. The rifle of claim 7, wherein:the outer pin is provided with a chordal flat positioned opposite the at least one ball bearing pocket.

9. The rifle of claim 8, wherein:the outer pin is further provided with at least one ball bearing loading hole positioned within the chordal flat.

10. The rifle of claim 7, wherein:the outer pin is provided with at least one sliding keyway having at least one detent hole, the at least one sliding keyway being engaged with a detent in one of the upper receiver and the lower receiver.

11. The rifle of claim 7, wherein:the head of the outer pin being provided with a dovetail recess and the knob being provided with a dovetail rotatably engaged with the dovetail recess of the head of the outer pin.

12. The rifle of claim 11, wherein:the head of the outer pin being provided with a detent bore and the knob being provided with detent notches; whereina detent ball and a detent spring is positioned within the detent bore and the detent ball is engaged with the detent notches to affect an incremental rotation of the knob relative to the outer pin.

13. A method for manufacturing a rifle having a Locking Takedown Pin, comprising the steps of: providing an upper receiver with at least one upper receiver lug and an upper receiver mating surface;providing a lower receiver with at least one lower receiver lug and a lower receiver mating surface;providing the Locking Takedown Pin with an outer pin having an anti-rotate slot, at least one ball bearing pocket, and a head;further providing the Locking Takedown Pin with an inner pin having a threaded section, a cylindrical section, an anti-rotate pin hole, at least one bearing loading recess, and at least one ramp or wedge-shaped profile;rotatably engaging a knob with the head of the outer pin and threadably engaged the knob with the threaded section of the inner pin;inserting an anti-rotate pin into the anti -rotate pin hole of the inner pin and slidably engaging the anti -rotate pin with the anti-rotate slot of the outer pin such that the inner pin is prevented from rotating with respect to the outer pin;engaging at least one ball bearing with the at least one ball bearing pocket such that the at least one ball bearing may protrude outside the outer pin but may not fully pass through the at least one ball bearing pocket;configuring the at least one ramp or wedge-shaped profile to selectively position the at least one ball bearing in a protruding position and in a withdrawn position as the inner pin translates axially within the outer pin upon rotation of the knob; andinserting the Locking Takedown Pin into the at least one lower receiver lug and into the at least one upper receiver lug such that the at least one lower receiver lug and the at least one upper receiver lug hold the lower receiver mating surface against the upper receiver mating surface.

14. The method of claim 13, further comprising the step of:providing the outer pin with a chordal flat positioned opposite the at least one ball bearingpocket.

15. The method of claim 14, further comprising the step of:further providing the outer pin with at least one ball bearing loading hole positioned within the chordal flat.

16. The method of claim 13, further comprising the steps of:providing the outer pin with at least one sliding keyway having at least one detent hole; and engaging the at least one sliding keyway with a detent in one of the upper receiver and the lower receiver.

17. The method of claim 13, further comprising the steps of:providing the head of the outer pin with a dovetail recess;providing the knob with a dovetail; androtatably engaging the dovetail of the knob with the dovetail recess of the head of the outer pin.

18. The method of claim 17, further comprising the steps of:providing the head of the outer pin with a detent bore;providing the knob with detent notches;positioning a detent ball and a detent spring within the detent bore;engaging the detent ball with the detent notches to affect an incremental rotation of the knob relative to the outer pin.

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