Gas Piston System Actuator Assembly for Rifle Automatic Ejection and Reload

Abstract

An actuator assembly includes a piston chamber assembly having a piston chamber and a pin receiving tube extending from the piston chamber. A gas transfer pin has a first end inserted in the pin receiving tube and a second end received in a rifle sight alignment bore. The gas transfer pin has a longitudinal bore in communication with the piston chamber. A piston member is slidably received in the piston chamber and includes a piston body with a piston member extension tube. The piston body includes a raised piston portion having piston rings, and a ring divider slot positioned between the piston rings. A rod assembly has a rod engagement end received in a piston member extension tube receiving bore. A piston clip has an arm extending through both the rod engagement end and the piston member extension tube connecting the rod assembly and piston member and a spiral end.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/391,188, filed on Oct. 8, 2010. The entire disclosure of the above application is incorporated herein by reference.

FIELD

The present disclosure relates to gas piston automatic ejection and reload operating systems for rifles.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

Automatic and semi-automatically operated rifles, such as the M16, also known as the AR15 automatic rifle, can include a gas operating system which uses a portion of the gas pressure generated during a firing operation to automatically eject a spent cartridge and in a continuous operation to load a new shell in the chamber for firing. Known gas operated systems for this purpose use a combination of a cylinder which receives gas pressure from a bypass line opening into the rifle barrel, and a piston slidably displaced in the cylinder by the gas pressure to operate an ejection and reload device.

Because of internal geometries of known piston and cylinder designs, these systems are subject to rapid buildup of gas residue such as burned gun powder. This buildup causes incomplete displacement or complete jamming of the piston which inhibits proper ejection of a spent cartridge and reloading of a new shell. Frequent cleaning of these systems can be required after as few as 200 rounds or less of operation.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

According to several embodiments, an actuator assembly for a weapon gas piston ejection and reload system includes a piston chamber assembly having a kidney shaped piston chamber and a pin receiving tube homogenously extending from an end of the piston chamber. A gas transfer pin has a first end slidably inserted in the pin receiving tube and a second end slidably received in a pin alignment bore of a rifle sight. The gas transfer pin has a pin longitudinal bore in communication with the piston chamber. A piston member is slidably received in the piston chamber and includes a piston body and a piston member extension tube extending axially away from the piston body. The piston body includes a raised piston portion having at least two piston rings; and a ring divider slot positioned directly between the at least two piston rings. An operating rod assembly has a rod engagement end slidably received in an engagement end receiving bore of the piston member extension tube. A piston clip has a clip arm extending through both the rod engagement end and the piston member extension tube to releasably connect the operating rod assembly to the piston member, and a clip spiral end having a bend leg bending greater than 120 degrees with respect to a longitudinal axis of piston clip.

According to further embodiments, the at least two piston rings of the piston member include first, second and third piston rings having first and second ring divider slots between successive ones of the piston rings. The piston member further includes a transition portion changing an elevation of the piston member extension tube with respect to a lower face of the piston body.

According to still other embodiments, the gas transfer pin is further slidable within the pin receiving tube during installation of the actuator assembly in the weapon to accommodate dimensional tolerances differing between differing ones of the weapon.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a right side elevational view of a rifle having a gas piston system actuator assembly of the present disclosure;

FIG. 2 is a left side elevational view of the rifle of FIG. 1;

FIG. 3 is a right perspective view of a receiver, rifle barrel and actuator assembly of the present disclosure after removal of component parts and hand guards from the rifle of FIG. 1;

FIG. 4 is an exploded assembly view of the receiver, rifle barrel and actuator assembly of FIG. 3;

FIG. 5 is a top plan view of the actuator assembly of FIG. 3 proximate a bolt carrier;

FIG. 6 is a side elevational view of the assembly of FIG. 5;

FIG. 7 is a top plan view of the actuator assembly of FIG. 3;

FIG. 8 is a side elevational view of the actuator assembly of FIG. 7;

FIG. 9 is an end elevational view of the actuator assembly of FIG. 7;

FIG. 10 is a cross sectional side elevational view taken at section 10 of FIG. 1;

FIG. 11 is a cross sectional end elevational view taken at section 11 of FIG. 10;

FIG. 12 is a cross sectional end elevational view taken at section 12 of FIG. 10;

FIG. 13 is a cross sectional side elevational view of area 13 of FIG. 10 showing the actuator assembly in a fully retracted position;

FIG. 14 is a cross sectional side elevational view modified from FIG. 13 showing the actuator assembly in a fully extended operating position;

FIG. 15 is a top plan view of a piston chamber assembly of the present disclosure;

FIG. 16 is an end elevational view of the piston chamber assembly of FIG. 15;

FIG. 17 is a cross sectional side elevational view taken at section 17 of FIG. 16;

FIG. 18 is a top plan view of an alternate embodiment piston member of the present disclosure;

FIG. 19 is a side elevational view of the piston member of FIG. 18;

FIG. 20 is a side elevational view of a gas transfer pin of the present disclosure;

FIG. 21 is a bottom plan view of the gas transfer pin of FIG. 20;

FIG. 22 is a cross sectional side elevational view taken at section 22 of FIG. 20; and

FIG. 23 is top perspective view of a portion of the actuator assembly and piston clip of the present disclosure.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Referring to FIG. 1, a rifle 10, which according to several embodiments represents an M16 (also commonly known as an AR15 assault rifle), is depicted. Rifle 10 includes a stock 12 connected to a receiver 14. The receiver 14 includes a hand grip 16, a trigger assembly 18, and a magazine receiver 20 for slidably receiving a magazine 22. An upper receiver portion 24 commonly acts as a carrying handle as well as a rear sight for rifle 10. An ejection port 26 provides for ejection of spent shell casings as rifle 10 is fired. A barrel 28 is connected to receiver 14 having a hand guard assembly 30 covering a portion of barrel 28 and used for manually supporting barrel 28 during firing. A front sight 32 is releasably connected to barrel 28 and establishes a forward support point for hand guard assembly 30. A flash suppressor 34 can also be commonly added to a free end of barrel 28.

Referring to FIG. 2, a left hand side of rifle 10 provides for a selector switch 36, which can be used to manually select between manual individual-round and automatic firing operations. The front sight 32 is connected to barrel 28 using first and second sight mounting legs 38, 40, which extend at least partially about the perimeter of barrel 28. Positioned directly between second sight mounting leg 40 and the forward end of hand guard assembly 30 is a hand guard cap 42. A delta ring 44 is used to connect barrel 28 to receiver 14. Delta ring 44 also provides for a rear connection or support point for hand guard assembly 30.

Referring to FIG. 3, and again to FIGS. 1 and 2, the hand guard assembly 30 is shown removed for clarity. An actuator assembly 46 of the present disclosure is shown in its installed position having a portion in contact with delta ring 44. Actuator assembly 46 is slidably positioned to contact receiver 14 and is connected to front sight 32 through hand guard cap 42. Actuator assembly 46 provides a passageway for a portion of the gas discharged during the firing operation to be returned toward receiver 14 and converted to a mechanical force to both eject a spent cartridge from receiver 14 as well as to reload a new shell.

Referring to FIG. 4, component parts of actuator assembly 46 include a bushing 48 having a bushing bore 50 sized to be slidingly received about an outer diameter “A” of a first rod member 52. First rod member 52 is a solid rod of a metal such as steel or aluminum. First rod member 52 is releasably connected to a second rod member 54 also made of a metal such as steel or aluminum using a rod connecting member 56. The combination of first and second rod members 52, 54 and rod connecting member 56 forms an operating rod assembly 58. Operating rod assembly 58 is in turn releasably pinned to a piston member 60.

Piston member 60 includes a piston body 62 having a raised piston portion 64 at a free end thereof. Raised piston portion 64, as well as piston body 62, is kidney-shaped to be slidably received within a kidney-shaped piston chamber 66 of a piston chamber assembly 68. Operating rod assembly 58 is releasably connected to piston member 60 as follows. A piston clip 70 of a steel material such as spring steel is used to releasably join operating rod assembly 58 to piston member 60. First, a second rod engagement end 72 of second rod member 54 has a diameter which is sized to be slidably received within an engagement end receiving bore 74 of a piston member extension tube 76 extending axially from piston member 60. Second rod engagement end 72 is slidably disposed within engagement end receiving bore 74 until a contact portion 77 of second rod member 54 contacts an end face of piston member extension tube 76. At this time, a first clip receiving bore 78 created through second rod engagement end 72 is co-axially aligned with a second clip receiving bore 80 transversely created through piston member extension tube 76. A clip arm 82 of piston clip 70 is slidably inserted through both second clip receiving bore 80 and simultaneously through first clip receiving bore 78 to releasably couple operating rod assembly 58 to piston member 60. By rotating piston clip 70 with respect to a longitudinal axis of clip arm 82, a clip spiral end 84 can be engaged to the outer perimeter of second rod member 54 preventing removal of clip arm 82 and thereby acting as a locking device to releasably lock piston clip 70 onto second rod member 54.

Once piston member 60 is releasably connected to operating rod assembly 58 using piston clip 70, a gas transfer pin 86 has a first end slidably inserted into a gas transfer pin receiving tube 88 of piston chamber assembly 68 until friction forces restrict further insertion. To retain gas transfer pin 86 and piston chamber assembly 68, a retention pin 90 is frictionally received in a retention pin bore 92 proximate a free end of gas transfer pin 86, which will be described in better detail with reference to FIG. 10. The raised piston portion 64 and piston body 62 of piston chamber assembly 68 are then slidably inserted into the piston chamber 66.

With actuator assembly 46 thus assembled, a bolt carrier 94 is slidably inserted into a barrel port 96 of receiver 14 such that a chamber 97 of receiver 14 is aligned with a shell port 98 of bolt carrier 94. With bolt carrier 94 thus positioned, an impactor end 100 of first rod member 52 is co-axially aligned such that impactor end 100 can strike an impact member 102 of bolt carrier 94 to axially displace bolt carrier 94 within receiver 14. A threaded bore 104 of a barrel nut 106 connected to barrel 28 is threadably connected to a plurality of male threads 108 of delta ring 44 to threadably connect barrel 28 using threaded bore 104 to delta ring 44.

Referring to FIG. 5 and again to FIG. 4, impact member 102 includes an impact face 114. Bushing 48 includes a bushing end face 115 such that an axial position of bushing 48 along first rod member 52 positions bushing end face 115 to act as a stop for axial travel of operating rod assembly 58 and piston member 60. First and second rod members 52, 54 are solid circular-shaped rods or if hollow have wall thicknesses selected to minimize axial bending as operating rod assembly 58 axially displaces bolt carrier 94. The piston clip 70 is shown with clip arm in its inserted position and clip spiral end 84 in frictional contact with second rod member 54. Contact portion 77 of second rod member 54 can have at least one flat surface providing for application of a tool such as a wrench to rotate second rod member 54 to co-axially align first and second clip receiving bores 78, 80 permitting installation of clip arm 82 of piston clip 70.

Referring to FIG. 6 and again to FIG. 1, in order to accommodate offset dimensions of rifle 10, a pin longitudinal axis 116 of gas transfer pin 86 is offset by an axial offset dimension “B” with respect to a first rod longitudinal axis 118 of first rod member 52. Piston member 60 therefore includes a transition portion 120, which provides for the axial offset dimension “B”.

Referring to FIG. 7 and again to FIG. 4, actuator assembly 46, having piston member 60 fully slidably received within piston chamber assembly 68, provides for an actuator assembly minimum length “C”. It is also noted that gas transfer pin 86, which is slidably received in a pin insertion direction “D” within gas transfer pin receiving tube 88, can extend outwardly with respect to gas transfer pin receiving tube 88 to varying lengths upon initial installation. This variable extension length (VEL) is provided so that when actuator assembly 46 is assembled into the rifle, the actual dimensional tolerances for the specific rifle are accommodated by further insertion of gas transfer pin 86 into gas transfer pin receiving tube 88 as the barrel 28 is fixed to rifle 10.

Referring to FIG. 8 and again to FIG. 1, when piston member 60 is fully slidably received within piston chamber assembly 68, an actuator assembly maximum height “E” is defined between a transition portion upper face 122 of piston member 60 and a lower face 124 of piston chamber assembly 68. Lower face 124 can also be co-linearly aligned with a similar lower face of transition portion 120. The actuator assembly maximum height “E” is maintained to provide for interior clearance and motion between piston member 60 and piston chamber assembly 68 when hand guard assembly 30 is installed on rifle 10.

Referring to FIG. 9, an actuator assembly maximum width “F” is defined by outside facing walls of piston chamber assembly 68. Also visible in FIG. 9 is that lower face 124 is defined at two locations of piston chamber assembly 68 due to the kidney shape of piston chamber assembly 68.

Referring to FIG. 10 and again to FIGS. 3 and 4, actuator assembly 46 is shown in its installed position with respect to front sight 32 and barrel 28. The installed position is defined by sliding contact between first rod member 52 and an outer surface of barrel nut 106. In the installed position, the transition portion upper face 122 of piston member 60 is positioned at a spacing dimension “G” with respect to a barrel longitudinal axis 128 of barrel 28. The gas transfer pin 86 has a first end 125 slidably received in gas transfer pin receiving tube 88 of piston chamber assembly 68, and a second end 126 slidably received in a pin alignment bore 127 extending partially through front sight 32 and axis parallel with a barrel longitudinal axis 128. Raised piston portion 64, at its maximum inserted position in piston chamber 66 of piston chamber assembly 68, minimizes a free volume of piston chamber 66. An alignment height “H” is also established in this position between an upper surface of first rod member 52 and barrel longitudinal axis 128 allowing sliding motion of first rod member 52. Gas transfer pin 86 is further axially restrained within pin alignment bore 127 by extension of retention pin 90 through a corresponding retention pin mating bore 129 created through front sight 32 and opening into pin alignment bore 127.

Referring to FIG. 11 and again to FIG. 10, the spacing dimension “G” between piston member extension tube 76 and barrel longitudinal axis 128 maintains clearance between piston member extension tube 76 and barrel 28. Clearance is therefore provided at a minimum diameter of barrel 28 shown, as well as at a maximum barrel diameter shown in FIG. 10 proximate to barrel nut 106.

Referring to FIG. 12, the kidney shape of piston body 62 includes an inner arc surface “J” whose radius starts at the center defining the diameter of barrel 28 such that continuous clearance is maintained to barrel 28 throughout the inner arc surface “J” of piston body 62. A minimum outer diameter “K” of barrel 28 is shown. The kidney shape of piston body 62 allows the inner arc surface “J” to be positioned at the closest point of approach while also allowing sliding motion of piston body 62 in a direction into and out of the page for FIG. 12.

Referring to FIG. 13, operation of actuator assembly 46 is accomplished as follows. Raised piston portion 64 is in sliding contact between upper and lower inner walls 130, 132 of piston chamber assembly 68. Upper and lower clearance spaces 134, 136 are maintained between piston body 62 and upper and lower inner walls 130, 132. Upper and lower clearance spaces 134, 136 provide a gas discharge path to atmosphere from piston chamber 66 past raised piston portion 64 during sliding motion of piston member 60. This provides for a throttling effect to reduce a pressure within piston chamber 66 over time. The pressure in piston chamber 66 is normally equal to atmospheric pressure until the rifle is fired. A biasing force provided by a spring (not shown) is therefore provided to normally bias piston member 60 in a piston return direction “M” to hold piston member 60 in direct contact with piston chamber assembly 68.

A pin longitudinal bore 138 extending axially within gas transfer pin 86 opens into piston chamber 66. A gas entrance bore 140 created in gas transfer pin 86 is oriented perpendicular with respect to and opens into pin longitudinal bore 138, and is aligned to open into a gas transfer chamber 142. Gas transfer chamber 142 is created in a leg portion 144 of second sight mounting leg 40. Leg portion 144 is in direct contact with an outer perimeter portion of barrel 28. Front sight 32 is positioned on barrel 28 to align transfer chamber 142 with an exhaust gas bypass port 146 which is oriented transverse to barrel longitudinal axis 128 and opens into a rifle bore 148. As a shell 150 travels through rifle bore 148 of barrel 28 to the right as viewed in FIG. 13, shell 150 is propelled by a gas pressure “P₁” in rifle bore 148. As shell 150 passes the entrance into exhaust gas bypass port 146, a portion of the gas pressure “P₁” in rifle bore 148, shown as pressure “P₂”, is directed into exhaust gas bypass port 146 in a gas inlet flow direction “L”. This pressurized gas flows from exhaust gas bypass port 146 into gas transfer chamber 142, through gas entrance bore 140 and pin longitudinal bore 138, and into piston chamber 66. Gas pressure “P₂” in piston chamber 66 acts on raised piston portion 64 to force piston member 60 in a piston operating direction “N”.

With continuing reference to FIG. 13 and again to FIG. 4, the piston chamber assembly 68 is substantially fixed in position by frictional engagement with gas transfer pin 86 which is frictionally engaged with the bore wall of pin alignment bore 127. An axial gap of approximately 0.051 to 0.089 cm (0.020 to 0.035 in) is originally present between hand guard cap 42 and an end 149 of gas transfer pin receiving tube 88 prior to firing a first round or shell 150. After approximately 2 to 4 rounds are fired, backpressure from the expanding gas in piston chamber 66 drives piston chamber assembly 68 forward in the piston return direction “M” with respect to the frictionally seated and pinned gas transfer pin 86 until gas transfer pin receiving tube 88 self seats against a flat plate portion 151 of hand guard cap 42. This “self seating” action provides subsequent longitudinal and latitudinal support and stability at the connection of gas transfer pin receiving tube 88 and gas transfer pin 86, enhances operation of the system including actuator assembly 46 in general, and minimizes stress risers at the junction of gas transfer pin 86 and flat plate portion 151.

Referring to FIG. 14 and again to FIG. 13, both piston member 60 and operating rod assembly 58 are shown after their full displacement in the piston operating direction “N”. At this time, the pressure within piston chamber 66 is reduced to a pressure “P₃”, which is less than pressure “P₂” due to gas expansion within piston chamber 66, as well as escape of a portion of the gas via upper and lower clearance spaces 134, 136 during sliding motion of raised piston portion 64. With further reference again to FIG. 4, the displacement of operating rod assembly 58 in the piston operating direction “N” produces an impact between impactor end 100 of first rod member 52 and impact member 102 of bolt carrier 94. Axial displacement of bolt carrier 94 in the piston operating direction “N” acts to eject a spent cartridge from shell port 98 via chamber 97 of receiver 14. A new shell is then automatically loaded into shell port 98 via a spring biasing force provided in the magazine as well known.

After shell 150 exits rifle bore 148, the pressure within rifle bore 148 quickly returns to atmospheric pressure, which also allows a remaining portion of the gas within piston chamber 66 to return through an opposite path and via exhaust gas bypass port 146 to equalize with atmospheric pressure in rifle bore 148. At this time, a biasing force acting on operating rod assembly 58 via bolt carrier 94 returns both operating rod assembly 58 and piston member 60 to the fully extended position shown in FIG. 13. The actuator assembly 46 repositioned to the fully extended position shown in FIG. 13 is thereafter ready for a next firing operation.

Referring to FIG. 15, according to several embodiments, piston chamber assembly 68 is a one-piece homogenous body having a kidney shaped chamber perimeter surface 152. The gas transfer pin receiving tube 88 homogeneously extending from piston chamber assembly 68 is substantially circular having a receiving tube diameter “0”.

Referring to FIG. 16, the kidney shape of piston chamber assembly 68 is more clearly visible having a curved chamber upper outer wall 154 and a curved chamber lower outer wall 156, which correspond in curvature to the upper and lower inner walls 130, 132. Each of the upper and lower inner walls 130, 132, as well as the chamber upper and lower outer walls 154, 156, share a common center of curvature. The opposed sides of piston chamber assembly 68 are mirror image curved surfaces, including a chamber side inner wall 158 and a chamber side outer wall 160 shown as the right hand sides as viewed in FIG. 16, which are duplicated on the left hand side. A gas flow passage 162 is created through an end wall 163 separating piston chamber 66 from gas transfer pin receiving tube 88. The common center of curvature is located at a distance “R” with respect to an axial centerline of gas flow passage 162 and an exemplary one of the radii “S” defining upper inner wall 130 extending from the center of curvature is shown.

Referring to FIG. 17 and again to FIG. 4, gas flow passage 162 provides for gas communication between piston chamber 66 and a receiving tube bore 164 separated by end wall 163. Because gas flow passage 162 is intended only for gas flow, a passage diameter “T” of gas flow passage 162 is smaller than the opening of piston chamber 66 and the diameter of receiving tube bore 164 which are sized to slidably receive piston member 60 and gas transfer pin 86 respectfully. A piston chamber inner length “U” of piston chamber 66 is predetermined based on the total axial throw required for actuator assembly 46 and therefore the maximum sliding displacement of piston member 60. According to several embodiments, piston chamber inner length “U” can be 3.15 cm (1.24 inches) when applied to an M16 rifle, but can vary at the discretion of the manufacturer.

Referring to FIG. 18 and again to FIGS. 4 and 6, an alternate embodiment piston member 166 functions to create a tortuous path for gas within piston chamber 66 escaping past the piston member 166. Piston member 166 includes a second clip receiving bore 168 which is substantially identical to piston member extension tube 76. A transition portion 170 is substantially identical to transition portion 120. A piston body 172, similar to piston body 62, occupies a smaller space envelope than a raised piston portion 174. Raised piston portion 174 is modified from raised piston portion 64 and includes at least two piston rings, and according to several embodiments includes first, second and third piston rings 176, 178, 180. The first, second, and third piston rings 176, 178, 180 are positioned proximate to a piston end wall 182.

Referring to FIG. 19 and again to FIG. 4, successive ones of the piston rings are separated by a ring divider slot, which can include first and second ring divider slots 188, 190. The purpose for separating the piston rings using the ring divider slots is to increase the turbulence in the gas flowing past the first, second and third piston rings 176, 178, 180, thereby further restricting gas flow escaping to atmosphere and maximizing the pressure available for displacement of piston member 166. Piston member 166 is connected to operating rod assembly 58 using piston clip 70 in the same manner as previously described with respect to piston member 60.

Referring to FIG. 20 and again to FIG. 7, gas transfer pin 86 includes a pin length “V”, which is predetermined to provide variable extension length (VEL) when inserted into gas transfer pin receiving tube 88 of piston chamber assembly 68. According to several embodiments, pin length “V” is 4.249 cm (1.673 inches) when used in an M16 rifle. To provide for ease of installation of gas transfer pin 86, a first and second chamfered end 192, 194 are provided at opposite ends. A recessed area 196 is spatially separated from retention pin bore 92. Recessed area 196 has a radius defining a recess arc of curvature “X”. A retention pin bore diameter “W” of retention pin bore 92 according to several embodiments is 0.201 cm (0.0790 inches) when used in an M16 rifle. A pin diameter “Y” of gas transfer pin 86 is controlled to a tolerance varying within multiple ten thousandths of an inch to permit the gas transfer pin 86 to be slidably received and then frictionally retained within gas transfer pin receiving tube 88.

Referring to FIG. 21, pin gas entrance bore 140 defines a substantially oval shape when created through recessed area 196. A circumferential slot 198 extends about a perimeter of gas transfer pin 86.

Referring to FIG. 22, pin longitudinal bore 138 of gas transfer pin 86 has a bore diameter “Z”. According to several embodiments, bore diameter “Z” is approximately 0.178 cm (0.070 inches) when used in an M16 rifle.

Referring to FIG. 23, piston clip 70 includes a bend 200 of approximately 90 degrees at the junction with clip arm 82 to align clip arm 82 for perpendicular positioning with respect to piston member extension tube 76 and second rod engagement end 72 (not visible in this view) of second rod member 54. No bends less than 120 degrees with respect to a longitudinal axis of piston clip 70 are used at a continuous bend clip spiral end 84 so that axial forces from movement of second rod member 54 do not create stress risers in clip spiral end 84. Clip spiral end 84 includes at least one bend leg 202 having a bend angle greater than 120 degrees, and according to several embodiments can further include a second bend leg 204 having a bend angle greater than 120 degrees.

Features and dimensions of the actuator assembly 46 of the present disclosure are described herein with respect to use with an M16 rifle. It should be evident these features and dimensions are not limited to the M16 rifle and can be varied to use an actuator assembly of the present disclosure in other rifles or weapon systems.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. An actuator assembly for a rifle gas piston ejection and reload system, comprising:

a piston chamber assembly having a piston chamber and a pin receiving tube integrally extending from an end of the piston chamber; and

a piston member slidably received in the piston chamber, the piston member including: a piston body having a raised piston portion including at least two piston rings; and a piston member extension tube extending axially away from the piston body.

2. The actuator assembly for a rifle gas piston ejection and reload system of claim 1, further including an operating rod assembly having a rod engagement end slidably received in an engagement end receiving bore of the piston member extension tube.

3. The actuator assembly for a rifle gas piston ejection and reload system of claim 2, further including a piston clip having a clip arm extending through both the rod engagement end and the piston member extension tube to releasably connect the operating rod assembly to the piston member.

4. The actuator assembly for a rifle gas piston ejection and reload system of claim 3, wherein the piston clip further includes a clip spiral end having a bend leg defining a continuous bend with respect to a longitudinal axis of the piston clip.

5. The actuator assembly for a rifle gas piston ejection and reload system of claim 1, further including a ring divider slot positioned directly between the at least two piston rings.

6. The actuator assembly for a rifle gas piston ejection and reload system of claim 1, further including a gas transfer pin having a first end slidably inserted in the pin receiving tube and a second end slidably received in a pin alignment bore of a rifle sight, the gas transfer pin having a pin longitudinal bore in communication with the piston chamber, wherein a backpressure from an expanding gas in the piston chamber during an initial use of the actuator assembly drives the piston chamber assembly forward with respect to the initially frictionally seated gas transfer pin until the pin receiving tube self seats against a flat plate portion of a hand guard cap.

7. The actuator assembly for a rifle gas piston ejection and reload system of claim 1, wherein the raised piston portion is located at a free end of the piston body.

8. The actuator assembly for a rifle gas piston ejection and reload system of claim 1, wherein the at least two piston rings of the piston member include first, second and third piston rings having first and second ring divider slots between successive ones of the piston rings.

9. The actuator assembly for a rifle gas piston ejection and reload system of claim 1, wherein the piston member further includes a transition portion changing an elevation of the piston member extension tube with respect to a lower face of the piston body.

10. The actuator assembly for a rifle gas piston ejection and reload system of claim 1, wherein the raised piston portion is in sliding contact between an upper inner wall and a lower inner wall of the piston chamber assembly, thereby creating an upper and a lower clearance space between the piston body and the upper and lower inner walls, the upper and lower clearance spaces providing a throttled gas discharge path to atmosphere from the piston chamber past the raised piston portion during sliding motion of the piston member.

11. An actuator assembly for a rifle gas piston ejection and reload system, comprising:

a piston chamber assembly having a piston chamber and a pin receiving tube homogenously extending from an end of the piston chamber;

a piston member slidably received in the piston chamber, the piston member including a piston body and a piston member extension tube extending axially away from the piston body, the piston body having: a raised piston portion having at least two piston rings; a ring divider slot positioned directly between the at least two piston rings; a lower face; and a transition portion changing an elevation of the piston member extension tube with respect to the lower face; and

an operating rod assembly having a rod engagement end slidably received in an engagement end receiving bore of the piston member extension tube.

12. The actuator assembly for a rifle gas piston ejection and reload system of claim 11, further including a gas transfer pin having a first end slidably inserted in the pin receiving tube during installation of the actuator assembly and a second end slidably received in a pin alignment bore of a rifle sight.

13. The actuator assembly for a rifle gas piston ejection and reload system of claim 12, wherein the gas transfer pin includes a pin longitudinal bore in communication with the piston chamber.

14. The actuator assembly for a rifle gas piston ejection and reload system of claim 12, wherein backpressure from expanding gas in the piston chamber initially drives the piston chamber assembly forward with respect to the initially frictionally seated gas transfer pin until the pin receiving tube self seats against a flat plate portion of a hand guard cap, thereafter providing longitudinal and latitudinal support and stability at a connection of the gas transfer pin receiving tube and the gas transfer pin.

15. The actuator assembly for a rifle gas piston ejection and reload system of claim 14, wherein an axial gap of approximately 0.051 to 0.089 cm (0.020 to 0.035 in) is originally present between the hand guard cap and an end of the gas transfer pin receiving tube.

16. The actuator assembly for a rifle gas piston ejection and reload system of claim 11, further including a piston clip having a clip arm extending through both the rod engagement end and the piston member extension tube to releasably connect the operating rod assembly to the piston member.

17. The actuator assembly for a rifle gas piston ejection and reload system of claim 16, wherein the piston clip further includes a clip spiral end having a bend leg including at least one bend bending at least 120 degrees with respect to a longitudinal axis of piston clip.

18. An actuator assembly for a rifle gas piston ejection and reload system, comprising:

a piston chamber assembly having a piston chamber and a pin receiving tube homogenously extending from an end of the piston chamber;

a piston member slidably received in the piston chamber, the piston member including a piston body and a piston member extension tube extending axially away from the piston body, the piston body having: a raised piston portion having at least two piston rings; and a ring divider slot positioned directly between the at least two piston rings;

an operating rod assembly having a rod engagement end slidably received in an engagement end receiving bore of the piston member extension tube; and

a piston clip having a clip arm extending through both the rod engagement end and the piston member extension tube to releasably connect the operating rod assembly to the piston member and a clip spiral end having a bend leg defining a continuous bend of at least 120 degrees with respect to a longitudinal axis of the piston clip.

19. The actuator assembly for a rifle gas piston ejection and reload system of claim 18, further including gas flow passage providing for gas communication between the piston chamber and a receiving tube bore separated by an end wall.

20. The actuator assembly for a rifle gas piston ejection and reload system of claim 19, wherein a passage diameter of the gas flow passage is smaller than an opening of the piston chamber and a diameter of the receiving tube bore.

21. The actuator assembly for a rifle gas piston ejection and reload system of claim 18, further including an actuator assembly releasably pinned using the piston clip to the piston member, the actuator assembly having:

a bushing with a bushing bore;

the bushing bore sized to be slidingly received about an outer diameter of a solid first rod member; and

a second rod member having the first rod member releasably connected to the second rod member using a rod connecting member.

22. The actuator assembly for a rifle gas piston ejection and reload system of claim 21, wherein a piston chamber inner length is predetermined based on a total axial throw required for the actuator assembly and thereby based on a maximum sliding displacement of the piston member.

23. The actuator assembly for a rifle gas piston ejection and reload system of claim 22, wherein the piston chamber inner length is approximately 3.15 cm (1.24 in).

24. The actuator assembly for a rifle gas piston ejection and reload system of claim 18, further including a gas transfer pin having a first end slidably received in the pin receiving tube and a second end slidably received in a pin alignment bore of a rifle sight, the gas transfer pin having a pin longitudinal bore in communication with the piston chamber.

25. The actuator assembly for a rifle gas piston ejection and reload system of claim 24, wherein an installed position of the actuator assembly with respect to a front sight and a barrel of a rifle is defined by:

a sliding contact between the first rod member and an outer surface of a barrel nut; and

a transition portion upper face of the piston member being positioned at a spacing dimension with respect to a barrel longitudinal axis of the barrel.

26. The actuator assembly for a rifle gas piston ejection and reload system of claim 24, further including:

a first end of the gas transfer pin being slidably received in a gas transfer pin receiving tube of the piston chamber assembly; and

a second end of the gas transfer pin being slidably received in a pin alignment bore extending partially through the front sight and axis parallel with the barrel longitudinal axis;

the gas transfer pin being further axially restrained within the pin alignment bore by extension of a retention pin through a retention pin mating bore opening into the pin alignment bore.