(12) United States Patent
`Ganglet al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,800,424 B2
`Aug. 12, 2014
`
`USOO8800424B2
`
`(54) CAPTURED SPRING ASSEMBLY FOR A
`FIREARM
`
`(75) Inventors: John P. Gangl, White Bear Lake, MN
`(US); Dave A. Adolfson, St. Paul, MN
`(US)
`(73) Assignee: J & K IP Assets, LLC, Cheyenne, WY
`US)
`(
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`(21) Appl. No.: 13/487,167
`
`(*) Notice:
`
`(22) Filed:
`(65)
`
`Jun. 2, 2012
`Prior Publication Data
`US 2013/0319217 A1
`Dec. 5, 2013
`
`(2006.01)
`
`(51) Int. Cl.
`F4 LA 3/78
`(52) U.S. Cl.
`USPC ............................................................ 89/198
`(58) Field of Classification Search
`USPC ............ 897198 199: 42A106.74.97: 267/70
`s
`s
`s
`is 2 67/71, 291
`See application file for complete search history.
`References Cited
`
`(56)
`
`U.S. PATENT DOCUMENTS
`
`1, 1968 Sturtevant ....................... 89,198
`3.366,011 A
`5, 1968 Edwards ........................... 42.74
`3,381405. A *
`3,731,590 A * 5, 1973 Zimmerman, Jr. .............. 89,163
`4,126,080 A * 1 1/1978 Reynolds ........................ 89,199
`4,344,352 A * 8/1982 Yates et al. ...................... 89,198
`4,522,107 A * 6/1985 Woodcock et al. ............. 89,196
`5,827,992 A * 10/1998 Harris et al. .......
`... 89,191.01
`5,909,002 A * 6/1999 Atchisson ....................... 89/130
`7,493,845 B2. 2.2009 Mantas ........................ 89.42.01
`8.430,015 B2
`4/2013 Faifer . . . . . . . . . .
`. . . . . . . . . . . . 89, 44.01
`2006/0236853 A1* 10/2006 Boersching et al. ............ 89,198
`* cited by examiner
`
`Primary Examiner — Gabriel Klein
`(74) Attorney, Agent, or Firm — Bennet K. Langlotz,
`Langlotz, Patent & Trademark Works, Inc.
`
`ABSTRACT
`(57)
`A captured spring assembly for a firearm has a rod having a
`forward and rearward ends, a movable buffer that defines an
`aperture that receives the forward end of the rod and is oper
`able to reciprocate between a forward battery position and a
`rearward retracted position, a coil spring that encompasses
`the rod, wherein the forwardend of the rod has a limit element
`having a head that is larger in diameter than the rod, wherein
`the buffer has an internal limit element that is larger in diam
`eter than the rod, and wherein the internal limit element has at
`least one portion that is smaller in diameter than the limit
`element head, but also larger in diameter than the rod. There
`may be a spring stop attached to the rearward end of the rod
`that is large enough for the spring to bear against and the
`buffer to strike against.
`
`2,361,180 A * 10/1944 Dobremysl ...................... 89.1.1
`3.298,282 A *
`1/1967 Loffler et al. ................... 89,198
`
`18 Claims, 7 Drawing Sheets
`
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`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`

`

`U.S. Patent
`US. Patent
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`Aug. 12, 2014
`Aug. 12, 2014
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`Sheet 1 of 7
`Sheet 1 017
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`US 8,800.424 B2
`US 8,800,424 B2
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`
`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`

`

`U.S. Patent
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`Aug. 12, 2014
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`Exhibit 1001
`
`

`

`U.S. Patent
`U.S. Patent
`
`Aug. 12, 2014
`Aug. 12, 2014
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`Exhibit 1001
`
`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`
`

`

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`U.S. Patent
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`Aug. 12, 2014
`Aug. 12, 2014
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`
`

`

`U.S. Patent
`U.S. Patent
`
`Aug. 12, 2014
`Aug. 12, 2014
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`Sheet 5 Of 7
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`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`

`

`U.S. Patent
`U.S. Patent
`
`Aug. 12, 2014
`Aug. 12, 2014
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`Sheet 6 of 7
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`Exhibit 1001
`
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`
`

`

`U.S. Patent
`U.S. Patent
`
`Aug. 12, 2014
`Aug. 12, 2014
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`Sheet 7 Of 7
`Sheet 7 of 7
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`US 8,800.424 B2
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`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`

`

`1.
`CAPTURED SPRING ASSEMBLY FOR A
`FIREARM
`
`US 8,800,424 B2
`
`FIELD OF THE INVENTION
`
`The present invention relates to firearms, and more particu
`larly to recoil springs for auto-loading rifles.
`
`BACKGROUND OF THE INVENTION
`
`10
`
`15
`
`25
`
`30
`
`35
`
`The AR-15 is a lightweight, 5.56 mm, air-cooled, gas
`operated, magazine-fed semi-automatic rifle, with a rotating
`lock bolt. The main mechanism of operation for the rifle is
`known as direct gas impingement. Gas is trapped from the
`barrel as the bullet moves past a gas port located above the
`rifle's front sight base. The gas rushes into the port and down
`a gas tube, located above the barrel, which runs from the front
`sight base into the AR-15's upper receiver. Here, the gas tube
`protrudes into a “gas key (bolt carrier key) which accepts the
`gas and funnels it into the bolt carrier.
`The bolt and bolt carrier together effectively form a piston,
`which is caused to move as the cavity in the bolt carrier fills
`with high pressure gas. The bolt is locked into the barrel
`extension, so this expansion forces the bolt carrier backward
`a short distance inline with the stock of the rifle to first unlock
`the bolt. As the bolt carrier moves toward the butt of the gun,
`the bolt campin, riding in a slot on the bolt carrier, forces the
`bolt to turn and unlock from the barrel extension. Once the
`bolt is fully unlocked it begins its rearward movement along
`with the bolt carrier. The bolt's rearward motion extracts the
`empty cartridge case from the chamber, and as soon as the
`neck of the case clears the barrel extension, the bolt's spring
`loaded ejector forces it out the ejection port in the side of the
`upper receiver. The bolt is much heavier than the projectile,
`and along with the recoil-spring pressure inside the stock
`buffer-tube performs the cartridge ejection function and
`chambers the following cartridge.
`Behind the bolt carrier is a plastic or metal buffer which
`rests in line with a bolt return spring that pushes the bolt
`carrier back toward the chamber to return the bolt into battery.
`40
`A groove machined into the upper receiver traps the campin
`and prevents it and the bolt from rotating into a closed posi
`tion. The bolt's locking lugs then push a fresh round from the
`magazine which is guided by feed ramps into the chamber. As
`the bolt's locking lugs move past the barrel extension, the cam
`pin is allowed to twist into a pocket milled into the upper
`receiver. This twisting action follows the groove cut into the
`carrier and forces the bolt to twist and "lock' into the barrels
`unique extension.
`The bolt return spring is a simple coil spring that is con
`fined by the outer walls of the extension tube. The spring rubs
`against the walls as it is compressed and extended. In some
`rifles, the result is a loud and annoying buZZing sound that can
`exceed a second in duration after each round is fired.
`One attempt to address this problem is the replacement of
`55
`the standard recoil spring buffer with a pneumatic piston
`system that uses compressed gas to store and return the recoil
`energy. However, this approach works only with rifles having
`buttstocks with full length extension tubes. Rifles or carbines
`having collapsible stocks, which have shorter extension
`tubes, cannot accommodate the pneumatic system. Pneu
`matic systems are also believed to have limited reliability and
`utility in extreme temperature environments.
`Therefore, a need exists for a new and improved captured
`spring assembly for a firearm that reduces the noise of the bolt
`return spring of a firearm with either a full length or collaps
`ible stock. In this regard, the various embodiments of the
`
`45
`
`50
`
`60
`
`65
`
`2
`present invention substantially fulfill at least some of these
`needs. In this respect, the captured spring assembly for a
`firearm according to the present invention Substantially
`departs from the conventional concepts and designs of the
`prior art, and in doing so provides an apparatus primarily
`developed for the purpose of constraining movement of the
`bolt return spring of a firearm by capturing the spring on an
`inner rod.
`
`SUMMARY OF THE INVENTION
`
`The present invention provides an improved captured
`spring assembly for a firearm, and overcomes the above
`mentioned disadvantages and drawbacks of the prior art. As
`Such, the general purpose of the present invention, which will
`be described Subsequently in greater detail, is to provide an
`improved captured spring assembly for a firearm that has all
`the advantages of the prior art mentioned above.
`To attain this, the preferred embodiment of the present
`invention essentially comprises a rod having forward and
`rearward ends, a movable buffer that defines an aperture that
`receives the forward end of the rod and is operable to recip
`rocate between a forward battery position and a rearward
`retracted position, a coil spring that encompasses the rod,
`wherein the forward end of the rod has a limit element having
`a head that is larger in diameter than the rod, wherein the
`buffer has an internal limit element that is larger in diameter
`than the rod, and wherein the internal limit element has at
`least one portion that is smaller in diameter than the limit
`element head, but also larger in diameter than the rod. There
`may be a spring stop attached to the rearward end of the rod
`that is large enough for the spring to bear against and the
`buffer to strike against. There are, of course, additional fea
`tures of the invention that will be described hereinafter and
`which will form the subject matter of the claims attached.
`There has thus been outlined, rather broadly, the more
`important features of the invention in order that the detailed
`description thereofthat follows may be better understood and
`in order that the present contribution to the art may be better
`appreciated.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a right side view of the current embodiment of the
`captured spring assembly for a firearm installed in a firearm.
`FIG. 1A is a side view of the current embodiment of the
`captured spring assembly for a firearm constructed in accor
`dance with the principles of the present invention.
`FIG. 1B is a side sectional view of the captured spring
`assembly of FIG. 1A.
`FIG. 2A is a right side sectional view of the captured spring
`assembly for a firearm of FIG. 1A attached to an upper
`receiver with the bolt carrier in the battery position.
`FIG. 2B is a top sectional view of the captured spring
`assembly for a firearm attached to an upper receiver of FIG.
`2A with the bolt carrier in the battery position.
`FIG.3A is a right side sectional view of the captured spring
`assembly for a firearm of FIG. 1A attached to an upper
`receiver with the bolt carrier in the out of battery position.
`FIG. 3B is a top sectional view of the captured spring
`assembly for a firearm attached to an upper receiver of FIG.
`3A with the bolt carrier in the out of battery position.
`The same reference numerals refer to the same parts
`throughout the various figures.
`
`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`

`

`US 8,800,424 B2
`
`3
`DESCRIPTION OF THE CURRENT
`EMBODIMENT
`
`4
`Surface also defines a ledge 64 at a point approximately mid
`way between the front and the rear.
`The front 78 of the end cap 76 is inserted into the rear 72 of
`the bore 62 of the resilient portion 60 and abuts the ledge 64.
`The rear 80 of the end cap is clamped to the rear 16 of the
`guide rod 12 by the head 88 of a rear screw 86. The threaded
`portion 90 of the rear screw is received by the threaded bore
`20 in the rear of the guide rod. The bore 138 in the rear of the
`end cap and the head of the rear screw are both chamfered to
`produce a flush fit. The rear of the end cap defines an out
`wardly protruding flange 82 that abuts the rear of the resilient
`portion and limits the rearward movement of the resilient
`portion. In the current embodiment, the resilient portion is
`made of urethane and the end cap is made of steel.
`The bolt return spring 52 encircles the guide rod 12 and is
`Sandwiched between the rear 32 of the slider 28 of the buffer
`22 and the front 70 of the resilient portion 60 of the shock
`absorber 58. The front 54 of the spring abuts the flange 36 of
`the slider, and the rear 56 of the spring abuts the rear of the
`central bore 84 in the end cap. The spring is a coil spring and
`fits tightly around the guide rod. The radiused ridge 74 facili
`tates insertion of the rear of the spring into the bore 62 in the
`front of the resilient portion and subsequently into the bore 84
`in the front 70 of the end cap. The radiused ridge 42 facilitates
`insertion of the front of the spring into the bore 134 in the rear
`32 of the slider.
`FIGS. 2A and 2B illustrate the improved captured spring
`assembly for a firearm 10 of the present invention. More
`particularly, the captured spring assembly is shown installed
`in the upper receiver 92 and extension tube 114 of a firearm
`200 in the in battery position.
`The upper receiver 92 has a left side 104, a right side 102,
`a front 96, and a rear 98. The right side defines an ejection port
`100 that communicates with a central bore 132. The rear of
`the upper receiver defines a threaded bore 112 that receives
`threads 126 on the front 122 exterior surface 116 of the
`extension tube 114. Abuttstock 214 is attached to the rear 124
`of the extension tube. The front of the upper receiver defines
`threads 140 that receive the rear of a barrel.
`A bolt carrier 106 is a tubular object that is slidably
`received by the bore 132 in the upper receiver 92. The front
`108 of the bolt carrier receives a bolt 130 (shown partially in
`FIG.2B and fully in FIG.3B). The rear 110 of the bolt carrier
`abuts the front 30 of the slider 28 of the buffer 22 of the
`captured spring assembly 10.
`The extension tube 114 has a central bore 120 that defines
`an interior surface 118. The captured spring assembly 10 is
`positioned within the extension tube such that the rear 80 of
`the end cap 76 abuts the rear of the bore 120. This constrains
`rearward movement of the shock absorber 58. The bore 120
`closely receives the buffer 22 with a sufficient diameter to
`permit the buffer to slide without lateral obstruction on the
`guide rod 12.
`In the in battery position, the bolt carrier 106 is at the
`forwardmost position within the upper receiver 92. The bolt
`return spring 52 urges the buffer 22 forward and keeps the
`front 30 of the slider 28 abutting the rear 110 of the bolt
`carrier.
`FIGS. 3A and 3B illustrate the improved captured spring
`assembly for a firearm 10 of the present invention. More
`particularly, the captured spring assembly is shown installed
`in the upper receiver 92 and extension tube 114 of a firearm in
`the out of battery position.
`In the out of battery position, the bolt carrier 106 is at the
`rearwardmost position within the upper receiver 92. A bore
`128 in the rear 110 of the bolt carrier receives the front 14 of
`the guide rod 12, which permits rearward movement of the
`
`10
`
`15
`
`25
`
`An embodiment of the captured spring assembly for a
`firearm of the present invention is shown and generally des
`ignated by the reference numeral 10.
`FIG. 1 illustrates the improved captured spring assembly
`for a firearm 10 of the present invention. More particularly,
`the captured spring assembly is shown installed in a firearm
`200. The firearm has a barrel 202, flash hider 204, upper
`receiver 92, magazine 206, trigger 208, trigger guard 210,
`pistol grip 212, ejection port 100, extension two 114, and
`buttstock 214. In the current embodiment, the firearm is an
`AR-15 carbine. The components of the firearm that interact
`with the captured spring assembly 10 will be described in
`more detail in the description of FIGS. 2A-3B.
`FIGS. 1A and 1B illustrate the improved captured spring
`assembly for a firearm 10 of the present invention. More
`particularly, the captured spring assembly consists of guide
`rod 12 with a buffer 22 slidably mounted on the front 14 of the
`guide rod, a shock absorber 58 affixed to the rear 16 of the
`guide rod, and a bolt return spring 52 that encircles the guide
`rod and is captured between the buffer and the shock absorber.
`The front of the guide rod defines a threaded bore 18, and the
`rear of the guide rod defines a threaded bore 20.
`The buffer 22 has a slider 28 with a central bore 134 that
`defines an interior surface 40. The central bore is sufficiently
`large to receive the front 54 of the bolt return spring 52. A
`flange 36 protrudes inwardly from the interior surface to
`30
`define an aperture 94 and to limit forward movement of the
`bolt return spring. The aperture 94 is sized to closely receive
`the front 14 of the guide rod 12 while still permitting the slider
`to slide along the guide rod. The rear 32 of the interior surface
`defines a radiused ridge 42. The front 30 of the exterior
`surface 38 of the slider defines an outwardly protruding flange
`34.
`Three O-rings 26 and three weights 24 encircle the exterior
`surface 38 of the slider 28. The O-rings separate the weights
`from one another and from the flange 34. A slot 136 in the
`exterior surface near the rear 32 of the slider receives a snap
`ring 44 to tightly clamp the O-rings and weights between the
`front flange and the Snap ring. The O-rings provide shock
`absorption for the weights and prevent the weights from rat
`tling. The weights add mass to the buffer 22 that buffers the
`buffer's motion. In the current embodiment, the O-rings are
`made of silicone or rubber and the weights are made of steel.
`However, the weights can be made of alternative materials
`and/or made thinner or thicker to provide different masses.
`Forward motion of the buffer 22 is constrained by the head
`48 of a front screw 46. The threaded portion 50 of the front
`screw is received by the threaded bore 18 in the front 14 of the
`guide rod 12. The head is sized with a diameter such that the
`head extends outwardly beyond the guide rod and is too large
`to pass through the aperture 94 defined by the flange 36 in the
`slider 28. The front screw can be unscrewed from the threaded
`bore to permit removal of the slider from the guide rod for
`installation of the bolt return spring 52.
`Rearward motion of the buffer 22 is limited by the shock
`absorber 58. The shock absorber 58 has a resilient portion 60
`that is supported by an end cap 76. The exterior 66 of the
`resilient portion 60 is tapered inwardly from the rear 72 to the
`front 70. The resilient portion has a central bore 62 that
`defines an interior surface 68. The central bore is sufficiently
`large to permit passage of the rear 16 of the guide rod 12 and
`to receive the rear 56 of the bolt return spring 52. The front of
`the interior surface defines a radiused ridge 74. The interior
`
`50
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`35
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`55
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`60
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`65
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`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`

`

`US 8,800,424 B2
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`5
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`bolt carrier within the upper receiver and into the front 122 of
`the bore 130 of the extension tube 120 when the trigger 208 is
`pulled and a round is fired. The rear of the bolt carrier pushes
`the buffer 22 rearward, thereby fully compressing the bolt
`return spring 52 between the buffer and the shock absorber
`58. The inertia resulting from the mass of the buffer and the
`resistance of the bolt return spring act to slow the rearward
`movement of the bolt carrier. Once the rearward movement of
`the buffer 22 is stopped by contact with the shock absorber 58,
`the bolt return spring 52 urges the buffer 22 against the rear
`110 of the bolt carrier 106 and pushes the bolt carrier forward
`to return the bolt carrier to the in battery position.
`The resilient portion 60 of the shock absorber 58 absorbs
`the impact of the buffer 22 against the shock absorber, the
`O-rings absorb the impact of the weights against one another
`and the flange 34 of the slider 28, and the bolt return spring 52
`is tightly held against the guide rod to limit vibration of the
`coil spring. All of these measures Substantially reduce the
`amount of noise produced by the operation of the captured
`spring assembly 10 compared to the typical bolt return spring
`arrangement of a conventional AR-15.
`In the context of the specification, the terms “rear and
`“rearward, and “front” and “forward' have the following
`definitions: “rear or “rearward” means in the direction away
`from the muzzle of the firearm while “front or “forward
`means it is in the direction towards the muzzle of the firearm.
`While a current embodiment of a captured spring assembly
`for a firearm has been described in detail, it should be appar
`ent that modifications and variations thereto are possible, all
`of which fall within the true spirit and scope of the invention.
`With respect to the above description then, it is to be realized
`that the optimum dimensional relationships for the parts of
`the invention, to include variations in size, materials, shape,
`form, function and manner of operation, assembly and use,
`are deemed readily apparent and obvious to one skilled in the
`art, and all equivalent relationships to those illustrated in the
`drawings and described in the specification are intended to be
`encompassed by the present invention.
`Therefore, the foregoing is considered as illustrative only
`of the principles of the invention. Further, since numerous
`modifications and changes will readily occur to those skilled
`in the art, it is not desired to limit the invention to the exact
`construction and operation shown and described, and accord
`ingly, all Suitable modifications and equivalents may be
`resorted to, falling within the scope of the invention.
`
`40
`
`45
`
`We claim:
`1. A buffer assembly for a firearm, the assembly compris
`ing:
`an elongated rod having a forward end and a rearward end;
`a cylindrical buffer that defines a buffer bore that receives
`the rod and is operable to reciprocate between a forward
`battery position and a rearward retracted position;
`a coil spring that encompasses the rod;
`the buffer bore receiving a forward portion of the spring:
`a resilient spring stop attached to the rearward end of the
`rod, the spring stop having a diameter larger than the
`spring diameter;
`wherein the resilient spring stop defines a central spring
`stop bore that receives a rear portion of the spring:
`wherein the forward end of the rod has a limit element
`having a head that is larger in diameter than the rod;
`wherein the buffer has an internal limit element that is
`larger in diameter than the rod;
`wherein the internal limit element has at least one portion
`that is smaller in diameter than the limit element head,
`but also larger in diameter than the rod;
`
`50
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`55
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`60
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`65
`
`6
`the spring stop having a limit spring Support Surface and the
`buffer having a buffer spring Support Surface, each
`spring Support Surface Supporting a respective end of the
`spring, and facing each other;
`wherein when the buffer is in the rearward retracted posi
`tion it contacts the spring stop Such that the spring is
`entirely contained by the central spring stop bore and the
`buffer bore when the buffer is in the rearward retracted
`position.
`2. The assembly of claim 1 wherein the rod limit element is
`removable for disassembly of the assembly.
`3. The assembly of claim 1 wherein the buffer comprises:
`a cylindrical slider that defines an aperture that receives the
`forward end of the rod and has an exterior surface that
`defines an outwardly protruding flange;
`a weight encompassing a portion of the exterior Surface;
`a O-ring positioned between the flange and the weight; and
`a snap ring removably connected to the exterior Surface of
`the slider to retain the weight on the slider.
`4. The assembly of claim 3 further comprising at least one
`additional weight and at least one additional O-ring, wherein
`the weights are separated by the O-rings and the Snap ring
`retains the weights on the slider.
`5. The assembly of claim 3 wherein the internal limit ele
`ment is an internally protruding flange positioned within the
`aperture of the slider.
`6. The assembly of claim 1 wherein the spring stop com
`prises:
`a rigid end cap that is attached to the rearward end of the
`rod; and
`a resilient bushing that is mounted on a forward portion of
`the end cap and defines an aperture that receives the
`rearward end of the rod.
`7. The assembly of claim 1 wherein the buffer has an
`interior cylindrical gap that receives the spring.
`8. The assembly of claim 7 wherein the buffer has an
`interior flange defining an aperture Smaller than the spring
`diameter and an enlarged bore portion larger than the spring
`diameter.
`9. The assembly of claim 1 wherein the spring stop has an
`interior cylindrical gap that receives the spring.
`10. Abuffer assembly for a rifle having a bolt carrier having
`a rear end and defining an aperture, the assembly comprising:
`a rod having a forward end and a rearward end;
`wherein the aperture of the bolt carrier receives the forward
`end of the rod when the bolt carrier is in a rearward
`retracted position;
`a movable buffer that defines an aperture that receives the
`forward end of the rod and is operable to reciprocate
`between a forward battery position and a rearward
`retracted position;
`the buffer having a forward end abutting the rear end of the
`bolt carrier;
`a coil spring that encompasses the rod;
`wherein the forward end of the rod has a limit element
`having a head that is larger in diameter than the rod;
`wherein the buffer has an internal limit element that is
`larger in diameter than the rod; and
`wherein the internal limit element has at least one portion
`that is smaller in diameter than the limit element head,
`but also larger in diameter than the rod.
`11. The assembly of claim 10 wherein the entire buffer is
`rearward of the entire bolt carrier.
`12. The assembly of claim 11 further comprising a spring
`stop attached to the rearward end of the rod that is large
`enough for the spring to bear against and the buffer to strike
`against.
`
`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`

`

`US 8,800,424 B2
`
`7
`13. The assembly of claim 12 wherein the buffer has an
`interior cylindrical gap that receives the spring and wherein
`the spring stop has an interior cylindrical gap that receives the
`spring such that when the buffer is positioned against the
`spring stop when the bolt carrier is in a rearward retracted
`position, the spring is received within the gaps.
`14. The assembly of claim 13 wherein the spring returns the
`buffer and the bolt carrier to the forward battery position from
`the rearward retracted position.
`15. The assembly of claim 12 wherein the spring stop
`comprises:
`a steel endcap that is attached to the rearward end of the rod
`by a screw; and
`a urethane bushing that fits over a forward portion of the
`end cap and defines an aperture that receives the rear
`ward end of the rod.
`16. A buffer assembly for a firearm, the assembly compris
`1ng:
`an elongated rod having a forward end and a rearward end;
`a cylindrical buffer that defines a bore that receives the rod
`and is operable to reciprocate between a forward battery
`position and a rearward retracted position;
`a coil spring that encompasses the rod;
`wherein the forward end of the rod has a limit element
`having a bead that is larger in diameter than the rod;
`wherein the buffer has an internal limit element that is
`larger in diameter than the rod;
`wherein the internal limit element has at least one portion
`that is smaller in diameter than the limit element head,
`but also larger in diameter than the rod; and
`wherein the buffer further comprises:
`a cylindrical slider that defines an aperture that receives
`the forward end of the rod and has an exterior surface;
`a weight encompassing a portion of the exterior Surface;
`and
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`10
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`15
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`25
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`30
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`8
`a snap ring removably connected to the exterior Surface
`of the slider to retain the weight on the slider.
`17. The buffer assembly of claim 16 further comprising:
`at least one additional weight and at least one O-ring,
`wherein the weights are separated by an O-ring and the
`Snap ring retains the weights on the slider.
`18. A buffer assembly for a firearm, the assembly compris
`1ng:
`an elongated rod having a forward end and a rearward end;
`a cylindrical buffer that defines a bore that receives the rod
`and is operable to reciprocate between a forward battery
`position and a rearward retracted position;
`the buffer including a body portion and a weight element
`on the body portion with a resilient element intervening
`between the weight and the body portion,
`a coil spring that encompasses the rod;
`a spring stop attached to the rearward end of the rod, the
`spring stop having a diameter larger than the spring
`diameter;
`wherein the spring stop comprises:
`a rigid end cap that is attached to the rearward end of the
`rod; and
`a resilient bushing that is mounted on a forward portion
`of the end cap and defines
`an aperture that receives the rearward end of the rod;
`wherein the forward end of the rod has a limit element
`having a head that is larger in diameter than the rod;
`wherein the buffer has an internal limit element that is
`larger in diameter than the rod; and
`wherein the internal limit element has at least one portion
`that is smaller in diameter than the limit element head,
`but also larger in diameter than the rod.
`
`k
`
`k
`
`k
`
`k
`
`k
`
`Petitioner Armaspec, Inc.
`Exhibit 1001
`
`