Recoil abatement stock with reduced rattle
09909835 ยท 2018-03-06
Assignee
Inventors
Cpc classification
F41C23/16
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F41C23/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F41C23/18
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
A recoil reduction system for a firearm. In some embodiments, the recoil reduction includes buffer tube housed within a buttstock, and a deformable structure for setting a clearance tolerance between the buffer tube and the buttstock to reduce lateral play while enabling smooth translation therebetween. In some embodiments, a guide pin and/or skid projections provide interference between the sliding components of the recoil reduction system when in a battery configuration, while releasing the interference during a recoil event.
Claims
1. A recoil reduction system, comprising: a buttstock defining a longitudinal bore; a slide member for coupling to a receiver; a biasing element operatively coupled with said buttstock and said slide member; a butt pad coupled to a proximal end of said buttstock; and a buffer tube configured for insertion into said longitudinal bore along an actuation axis, said longitudinal bore being configured for a clearance fit with said buffer tube, wherein said buttstock includes a deformable structure adapted to selectively reduce a dimension of said longitudinal bore to configure said buttstock for a close sliding fit between said longitudinal bore and said buffer tube.
2. The recoil reduction system of claim 1, wherein said dimension is a diameter of said longitudinal bore about said actuation axis.
3. The recoil reduction system of claim 1, wherein said deformable structure is located proximate a distal end of said buttstock.
4. The recoil reduction system of claim 3, wherein said deformable structure includes: a longitudinal through slot defined proximate said distal end of said buttstock, said longitudinal slot being at least partially defined by opposing lateral sides; and a fastener arranged to draw said opposing lateral sides towards each other to reduce said dimension of said longitudinal bore.
5. The recoil reduction system of claim 1, wherein: said buffer tube includes a plurality of recesses formed on a lateral side thereof; said buttstock includes structure defining a lateral through-passage for selective alignment with any one of said plurality of recesses; and a set pin is disposed within said lateral through-passage for selective engagement with any one of said plurality of recesses for anchoring said buffer tube to said buttstock.
6. The recoil reduction system of claim 5, comprising: a lever pivotally mounted to said buttstock and operatively coupled with said set pin for selectively removing said set pin from said any one of said plurality of recesses.
7. The recoil reduction system of claim 6, wherein said biasing element is coupled to said set pin for biasing said set pin to engage with said buffer tube.
8. The recoil reduction system of claim 1, wherein said butt pad defines an open cell structure that is exposed to ambient air.
9. The recoil reduction system of claim 1, wherein any one of said buttstock, said butt pad, and said biasing element is formed of a polymer material.
10. The recoil reduction system of claim 1, wherein said longitudinal bore is defined by a bore wall in the buttstock, wherein the bore wall includes at least one rib that protrudes toward said actuation axis, said dimension of said longitudinal bore being referenced from said at least one rib.
11. The recoil reduction system of claim 1, wherein said deformable structure is unitary with said buttstock.
12. A method for reducing a dimensional clearance of the recoil reduction system of claim 1, comprising: (a) inserting said buffer tube into said longitudinal bore of said buttstock; and (b) adjusting said deformable structure of said buttstock to selectively adjust a dimension of said longitudinal bore and to define said close sliding fit between said buffer tube and said longitudinal bore, said close sliding fit enabling translation of said buffer tube within said longitudinal bore along said actuation axis while reducing lateral play between said buffer tube and said longitudinal bore.
13. The method of claim 12, wherein the step of adjusting said deformable structure is performed with a fastener arranged to selectively adjust said dimension of said longitudinal bore.
14. The method of claim 12, comprising: providing the recoil reduction system of claim 1 in a kit, providing a set of assembly instructions on a tangible medium, said set of assembly instructions including step (a) and step (b).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
(14) Referring to
(15) A biasing element 48 (
(16) Referring to
(17) A maximum bias member displacement 56 (
(18) In various embodiments, the biasing element 48 comprises a coiled spring 58. In some embodiments, the biasing element 48 also includes a second spring 60 nested within the coiled spring 58. By nesting springs in this manner, the springs act in parallel, providing a stiffer combined spring rate than either one of the springs 58, 60. In one non-limiting example, the coiled spring 58 is an ISO-204 die spring type having a spring rate of 25 N/mm and the second spring 60 is an ISO-203 die spring type having a spring rate of approximately 3.2 N/mm, for a combined spring rate of approximately 28 N/mm. Such springs are commercially available from, for example, Associated Spring Raymond of Maumee, Ohio, U.S.A. The coil spring(s) 58, 60 may be made of any suitable material available to the artisan, including carbon steel or a high resilience polymer. In other embodiments, the biasing element 48 includes some other suitably elastic member, such as a rubber cylinder (not depicted).
(19) Referring to
(20) In some embodiments, a deformable structure 112 is located proximate the distal end 104 of the buttstock 42. In one embodiment, the deformable structure 112 includes a longitudinal through-slot 114 defined proximate the distal end 104 of the buttstock 42, the longitudinal through-slot 114 being at least partially defined by opposing laterally-facing sides 116. Also, the deformable structure 112 may be unitary with the buttstock 42. A fastener 118 may be arranged to draw the opposing laterally-facing sides 116 towards each other to reduce the dimension 106 of the longitudinal bore 102. Herein, longitudinal is defined as being in a direction that is parallel to the actuation axis 49, whereas lateral is defined as being in a direction that is perpendicular to the actuation axis 49.
(21) In assembly, the buffer tube 108 is slid into the longitudinal bore 102. The fastener 118 is adjusted so that the deformable structure 112 provides a close sliding fit between the buffer tube 108 and the dimension 106 of the longitudinal bore 102. The close sliding fit enables the buffer tube 108 to readily translate within the longitudinal bore 102 along the actuation axis 49, yet eliminate perceptible lateral play between the buffer tube 108 and the dimension 106 of the bore 102.
(22) Functionally, the adjustment capability of the deformable structure 112 compensates for fabrication tolerances of the longitudinal bore 102 or, when utilized, ribs 110. For example, a buttstock 42 that comprises a molded polymer material may be subject to large dimensional variations. Because of the adjustment capability of the deformable structure 112, the dimension 106 of the longitudinal bore 102 is deliberately oversized in some embodiments so that the buffer tube 108 does not bind within the longitudinal bore 102, and the adjustment made as described above to reduce the clearance and eliminate perceptible lateral play between the buffer tube 108 and the bore 102. That is, the close sliding fit eliminates rattling between the buffer tube 108 and the buttstock 42 while enabling the buffer tube 108 to be translated with in the bore 102 of the buttstock 42.
(23) Furthermore, the adjustment may be a one-time adjustment, or at least one that requires infrequent adjustment. Unlike prior art stocks that utilize an engagement lever that must be disengaged every time the effective length of the stock is changed, the disclosed deformable structure 112 does not have to be disengaged to change the effective length of the stock. This enables stock length adjustment with fewer steps and with fewer mechanical components.
(24) In some embodiments, the recoil reduction system 32 is provided as part of a kit for retrofitting to an existing firearm. In various embodiments, instructions for assembly, adjustment, and operation of the recoil reduction system are provided on a tangible medium, the instructions being based on assembly, adjustment, and operation of the recoil reduction system 32 as provided herein. Herein, a tangible medium includes a paper document and/or a computer readable medium, such as a compact disk, flash drive, or internet-accessible server. In all instances, the tangible medium provides instructions that are non-transitory.
(25) Referring to
(26) In some embodiments, each lateral face 132 of the slide member 36 further includes an elongate protrusion 136 disposed adjacent the respective channel 134 that is elongate in the direction of the actuation axis 49. Each elongate protrusion 136 projects laterally outward from the slide member 36 and extends parallel to the actuation axis 49 and also defines an upper surface 136a and a lower surface 136b.
(27) The slide member 36 may also include a ridge 138 that projects rearward and partially surrounds a rearward face 142 of the slide member 36. In some embodiments, the rearward face 142 also includes a raised portion 144 that is also partially surrounded by the ridge 138, the raised portion 144 being substantially concentric about the actuation axis 49. The ridge 138 and the raised portion 144 of the rearward face 142, in certain embodiments, cooperate to capture a distal end 146 of biasing element 48 (e.g., coil spring 58) within the slide member 36. The ridge 138 may also serve as a rearward stop for the slide member 36 that contacts an obstruction to stop rearward travel of the slide member 36 relative to the buttstock 42.
(28) A pair of canted guide slots 168 are formed in the slide member 36, one each at an inward face of each channel 134, and each defining a mirror image of the other about the actuation axis 49. In some embodiments, a forward portion 172 of each canted guide slot 168 is substantially parallel to the actuation axis 49, while a rearward portion 174 of each canted guide slot 168 is canted relative to the actuation axis 49. In some embodiments, the canted guide slots are through-slots. A guide pin 176 may be disposed through the hand grip assembly 50 and the canted guide slots 168 of the slide member 36, the guide pin 176 being anchored on each end to opposing faces of the hand grip assembly 50.
(29) Referring to
(30) Each of the rails 164 are slidably engaged within a respective one of the channels 134 defined on the slide member 36. In one embodiment, the rails 164 and channels 134 are dimensioned so that a distal end 165 (best seen in
(31) In the depicted embodiment, the body portion 154 of the housing 152 further defines a pair opposed grooves 166, each disposed adjacent a respective one of the rails 164 of the body portion 154. Each groove 166 defines an upper surface 166a and a lower surface 166b that and is positioned and dimensioned so that a respective one of the elongate protrusions 136 of the slide member 36 will slide longitudinally within the groove 166.
(32) Referring to
(33) Functionally, the guide pin 176 defines the rearward or battery position of the recoil reduction system 32 relative to the receiver 34, and guides the slide member 36 through an actuation path during a recoil event. In the battery configuration, the guide pin 176 is registered against rearward ends 178 of the canted guide slots 168 by the biasing element 48. The canted or rearward portion 174 of the canted guide slot 168 causes the slide member 36 to be slightly elevated relative to the actuation axis 49 within the hand grip assembly 50 when the recoil reduction system 32 is in the battery configuration. The elevation may be characterized as an offset 179, best seen in
(34) In an alternative embodiment, the canted guide slots 168 may be formed on the housing (not depicted) with circular apertures (not depicted) formed on the slide member 36 for holding the guide pin 176. In such an embodiment, the slide member 36 would carry the guide pin 76 along the canted guide slots of the hand grip assembly 50, to the same effect as described above.
(35) Referring to
(36) Upon discharge of the firearm (
(37) In further reference to
(38) A front end portion 197 of the buffer tube 108 includes external threads 198 that mate with the internal threads 185 of the threaded insert 184 of the hand grip assembly 50. A castle nut 202 also engages the external threads 198 of the buffer tube 108, so that, when tightened against the hand grip assembly 50, the castle nut 202 imparts an axial load between the external threads 198 of the buffer tube 108 and the internal threads 185 of the threaded insert 184. During assembly, a bonding paste, such as LOCTITE, may be applied between the external threads 198 of the buffer tube 108 and the internal threads 185 of the threaded insert 184. The bonding paste and the axial force exerted by the castle nut 202 act to resist rotation between the buffer tube 108 and the hand grip assembly 50.
(39) Referring to
(40) During a recoil event, the slide member 36 is translated rearward, dislodging the guide pin 176 from the rearward end 191b of the flared slot 190. In some embodiments, the guide pin 176 translates freely between and without contacting the opposing boundaries 190a and 190b of the flared through-slot 190 during the recoil stroke. A representative position of the guide pin 176 during the recoil stroke is depicted in phantom at 176. The location of the guide pin 176 within the flared through-slot 190 is determined by other alignment and guide mechanisms of the recoil reduction system 32, such as the channels 134 and rails 164, and/or the protrusions 136 and grooves 166 (
(41) Referring to
(42) In various embodiments, a cross pin 228 is disposed in the circular hole 224 of the adjustment pin 212, the cross pin 228 extending parallel to the y-axis. In some embodiments, an anchor pin 232 extends across the bore 218 and through the slotted through hole 226, the anchor pin 232 being perpendicular to the pin actuation axis 219 and oriented in a direction parallel to the y-axis. The anchor pin 232 is secured on both ends to the buttstock 42. In the depicted embodiment, as spring 234 is disposed in the hollow tube 220, captured between the end portion 222 and the anchor pin 232.
(43) In the depicted embodiment, the bore 218 is aligned with a selected one of the plurality of adjustment notches 216, such that the adjustment pin 212 extends out of the bore 218 and into selected notch 216. In
(44) During actuation of the adjustment pin 212, the slotted through hole 226 slides over the stationary anchor pin 232 as the end portion 222 is drawn closer to the anchor pin 232. The spring 234 becomes compressed between the end portion 222 and the anchor pin 232. The compression biases the adjustment pin 212 so that, upon release of the adjustment lever 214, the adjustment pin 212 is urged back into contact with the buffer tube 108 and, perhaps after some additional positioning of the buffer tube 108 within the bore 102, into one of the adjustment notches 216.
(45) The concept of creating an interfering engagement between the slide member 36 and the hand grip assembly 50 to reduce rattle and play when in the battery configuration can be effected by other mechanisms besides the canted guide slots 168. In various embodiments, the selectively interfering engagement is provided by a widening or narrowing of one sliding structure relative to its mating structure. Some alternative concepts and mechanisms are discussed below.
(46) Referring to
(47) For the flared width slide system 270, the hand grip assembly 50, within which the slide member 36 is housed, is configured with complementary flared surfaces 282 that complement the flared surfaces 272 when in the battery configuration. That is, a first width 284 defined between the complementary flared surfaces 282 at a distal portion 285 of the body portion 154 of the housing 152 of the hand grip assembly 50 is of smaller dimension than a second width 286 defined between the complementary flared surfaces 282 at a proximal portion 287 of the body portion 154.
(48) In various embodiments, the flared surfaces 272 of the slide member 36 is defined by one or both of the channels 134 and/or by one or both of the protrusions 136 of the slide member 36 (
(49) Functionally, the flared surfaces 272 of the slide member 36 are registered against the flared surfaces 282 of the body portion 154 when the recoil reduction system 32 is in the battery configuration (
(50) Referring to
(51) For the inclined height slide system 300, the hand grip assembly 50, within which the slide member 36 is housed, is configured with complementary inclined surface 312 that complements the inclined surface 302 when in the battery configuration. That is, the inclined surfaces 302, 312 are configured so that the inclined surface 302 is firmly registered against inclined surface 312 when the recoil reduction system 32 is in the battery configuration. In the depicted embodiment, the heights of the channel 134 and heights of the rail 164 are matched across a length 314 in the x-direction.
(52) In the depicted embodiment, the inclined surfaces 302, 312 are defined by the channel 134 and the rail 164, respectively. Alternatively or in addition, other surfaces of the slide member 36 and body portion 154 can be utilized to define complementary inclined surfaces. For example, inclined surfaces can be utilized between the elongate protrusions 136 and grooves 166 mutatis mutandis.
(53) Functionally, the inclined surface 302 of the slide member 36 is registered against the inclined surface 312 of the rail 134 when the recoil reduction system 32 is in the battery configuration (
(54) References to embodiment(s), disclosure, present disclosure, embodiment(s) of the disclosure, disclosed embodiment(s), and the like contained herein refer to the specification (text, including the claims, and figures) of this patent application that are not admitted prior art.
(55) For purposes of interpreting the claims for the embodiments of the inventions, it is expressly intended that the provisions of 35 U.S.C. 112(f) are not to be invoked unless the specific terms means for or step for are recited in the respective claim.