The present invention relates to a buffer assembly for a firearm. The buffer assembly includes at least one magnet that offsets an inertial event that occurs during the firing action of a firearm.
The invention provides a buffer assembly for a firearm, the buffer assembly comprising: a buffer tube including a closed rear end; an action spring in the tube; and a buffer in the tube and engaging the action spring, the buffer including a buffer body defining an internal buffer cavity, a rear end cap covering a rear end of the buffer body, a front end cap covering a front end of the buffer body, and an internal assembly within the buffer cavity, the internal assembly comprising at least one weight, a first magnet and a second magnet wherein a magnetic repelling force between the first magnet and the second magnet biases the weight to an at-rest position within the internal assembly; and wherein in response to an inertial event the at least one weight overcomes the bias of the magnetic repelling force to achieve a dead-blow condition to at least partially offset an effect of the inertial event.
In some embodiments, the magnetic repelling force establishes a delay interval between the occurrence of the inertial event and the occurrence of the resulting dead-blow condition. In some embodiments, the first magnet is encapsulated with the weight in an encapsulation. In some embodiments, the inertial event is generated by a rearward stroke of the buffer and the dead-blow condition occurs at the beginning of the rearward stroke. In some embodiments, the first magnet is proximate the weight and the second magnet is at least partially disposed within the rear end cap of the buffer body. In some embodiments, the magnetic repelling force adjusts a magnitude of an impact force arising from the dead-blow condition. In some embodiments, the inertial event is generated by a rearward stroke of the buffer and the dead-blow condition occurs at both a beginning of the rearward stroke and an end of the rearward stroke. In some embodiments, the at least one weight includes a first weight and a second weight, the first weight located rearwardly within the buffer body relative to the second weight, the first magnet is positioned proximate the first weight, and the second magnet is positioned proximate the second weight. In some embodiments, the magnetic repelling force resets the internal assembly to the at-rest condition after a recover time has passed following the occurrence of the dead-blow condition.
The invention also provides a firing assembly for a firearm, the firing assembly comprising: a bolt carrier movable in a rearward stroke and a forward stroke as part of a firing and loading action of the firearm; and a buffer assembly including a buffer tube including a closed rear end, an action spring in the tube, and a buffer in the tube and engaging the action spring, the buffer including a buffer body defining an internal buffer cavity, a rear end cap covering a rear end of the buffer body, a front end cap engaged with the bolt carrier, and an internal assembly within the buffer cavity, the internal assembly comprising at least one weight, a first magnet, and a second magnet; wherein a magnetic repelling force between the first magnet and the second magnet biases the weight to an at-rest position within the internal assembly; wherein the buffer is driven in rearward and forward strokes corresponding to the rearward and forward strokes of the bolt carrier and under the influence of respective rearward motion of the bolt carrier and a forward biasing force of the action spring; wherein as a result of at least one of the rearward and forward strokes, at least one inertial event occurs; wherein in response to the inertial event the at least one weight overcomes the bias of the magnetic repelling force to achieve a dead-blow condition to at least partially offset an effect of the inertial event.
In some embodiments, the magnetic repelling force adjusts a magnitude of an impact force arising from the dead-blow condition. In some embodiments, the magnetic repelling force establishes a delay interval between the occurrence of the inertial event and to the occurrence of the dead-blow condition. In some embodiments, the inertial event is generated by a rearward stroke of the buffer and the dead-blow condition occurs at the end of the rearward stroke. In some embodiments, the second magnet is proximate the weight and the first magnet is at least partially disposed within the front end cap of the buffer body. In some embodiments, a magnetic attracting force between the first magnet and the bolt carrier biases the bolt carrier towards the buffer body. In some embodiments, the first magnet is proximate the weight and the second magnet is at least partially disposed within the rear end cap of the buffer body, wherein the internal assembly further comprises a third magnet disposed at least partially within the front end cap of the buffer body, and wherein a magnetic attracting force between the third magnet and the bolt carrier biases the bolt carrier towards the buffer body. In some embodiments, a radius of the third magnet is larger than a radius of the cavity of the buffer body. In some embodiments, the magnetic repelling force resets the internal assembly to the at-rest condition after a recover time has passed following the occurrence of the dead-blow condition.
The invention also provides a method of at least partially offsetting an inertial event in a firing assembly of a firearm, the method comprising: evaluating an inertial event of a buffer assembly in a firearm, the buffer assembly having a buffer body, with at least one weight moveable within an internal space of the buffer body, and a first magnet and a second magnet between which a magnetic repelling force biases the weight to an at-rest position in the internal assembly, wherein in response to the inertial event the at least one weight overcomes the bias of the magnetic repelling force to achieve a dead-blow condition to at least partially offset an effect of the inertial event, and wherein the magnetic repelling force adjusts a magnitude of an impact force arising from the dead-blow condition and establishes a delay interval between the occurrence of the inertial event and to the occurrence of the dead-blow condition; determining an impact force that is a minimizing impact force and a delay interval that is a minimizing delay interval such that the minimizing impact force and minimizing delay interval combination at least partially offset the inertial event; and adjusting properties of the components of the firearm to achieve the minimizing impact force and the minimizing delay interval combination.
In some embodiments, the adjusted component properties are those of the first magnet and the second magnet. In some embodiments, the adjusted component properties are those of the weight. In some embodiments, the adjusted component properties are those of the encapsulation.
The invention also provides a firing assembly for a firearm, the firing assembly comprising: a bolt carrier movable in a rearward stroke and a forward stroke as part of a firing and loading action of the firearm; and a buffer assembly including a buffer tube including a closed rear end, an action spring in the tube, and a buffer in the tube and engaging the action spring, the buffer including a buffer body defining an internal buffer cavity, a rear end cap covering a rear end of the buffer body, a front end cap engaged with the bolt carrier, and an internal assembly within the buffer cavity, the internal assembly comprising at least one weight and a magnet; wherein a magnetic attracting force between the magnet and the bolt carrier biases the bolt carrier and the buffer towards each other; wherein the buffer is driven in rearward and forward strokes corresponding to the rearward and forward strokes of the bolt carrier and under the influence of respective rearward motion of the bolt carrier and a forward biasing force of the action spring; wherein as a result of at least one of the rearward and forward strokes, at least one inertial event occurs; wherein during the inertial event, the magnetic attracting force biases the bolt carrier and the buffer towards each other to at least partially offset an effect of the inertial event.
In some embodiments, the internal assembly includes a dead-blow biasing mechanism. In some embodiments, the dead-blow biasing mechanism includes at least a second magnet.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
The buffer 240 includes a cylindrical buffer body 270, a front end cap 280, and a rear end cap 290. The buffer body 270 includes a front end 270a and a rear end 270b. The front end cap 280 may be threaded onto the front end 270a of cylindrical buffer body 270, permanently affixed to the buffer body 270, or integrally formed with the buffer body 270. The front end cap 280 is of wider diameter than the buffer body 270 to define a shoulder 300. The rear end cap 290 is made of a resilient material such as urethane to cushion the impact of the buffer 240 on the rear end 220b of the internal space 220c of the buffer tube 220 when the buffer 240 is driven rearward as part of the firearm's firing and reloading action. A retaining pin or roll pin 310 secures the rear end cap 290 to the buffer body 270.
The action spring 230 and buffer 240 are inserted through the open front end 220a of the buffer tube 220 into the internal space 220c. The rear end 230b of the action spring 230 bottoms out in and abuts against the closed rear end 220b of internal space 220c of the buffer tube 220. The buffer body 270 is surrounded by the coils of the action spring 230. The front end 230a of the action spring 230 abuts the shoulder 300 of the front end cap 280. The action spring 230 and buffer 240 are retained in the buffer tube 220 with a buffer retaining pin 340 in the lower receiver 140. The buffer retaining pin 340 is spring biased and can be manually deflected into the lower receiver 140 to provide clearance for insertion of the action spring 230 and buffer 240. When released from its deflected condition, the buffer retaining pin 340 extends to trap the action spring 230 and buffer 240 in the buffer tube 220.
A forward stroke commences under the influence of the action spring 230. During the forward stroke, the action spring 230 drives the buffer 240 and bolt carrier 215 forward. The bolt carrier 215 collects a new round from a magazine under the upper receiver 110 and drives the new round into the battery condition. The forward stroke ends when the bolt carrier 215 is in the battery condition, ready to fire the new round.
The present invention relates to a dead-blow mechanism inside the buffer body 270, and more specifically to a magnetic dead-blow biasing mechanism 460 which is part of the dead-blow mechanism. As will be discussed in more detail below, the dead-blow mechanism has two conditions: an at-rest condition and a dead-blow condition. The dead-blow biasing mechanism 460 biases the dead-blow mechanism into the at-rest condition. The dead-blow condition is achieved by overcoming the biasing force of the dead-blow biasing mechanism 460 in response to an inertial event. The purposes of the dead-blow mechanism in the buffer body 270 is to reduce bounce of the bolt carrier 215 or slow down acceleration of the bolt carrier 215 at the beginning or end of the rearward stroke or the beginning or end of the forward stroke, when inertial events occur. Reducing bounce and slowing down acceleration can improve shooting accuracy and optimize the timing of the firing action, as will be described in more detail below.
The illustrated embodiments also include a magnetic dead-blow biasing mechanism 460 in the form of a first magnet 450a and a second magnet 450b (the embodiment illustrated in
As will be explained below, the magnetic dead-blow biasing mechanism 460 can be configured to achieve the dead-blow condition at the end of the rearward stroke, the beginning of the rearward stroke, or at both the beginning and end of the rearward stroke. The magnetic dead-blow biasing mechanism 460 might be set up to achieve the dead-blow condition at the end of the rearward stroke when the action spring 230 is overly stiff or overly preloaded. In this situation, referred to as “oversprung,” the action spring 230 may cause the buffer 240 and bolt carrier 215 to transition from the rearward stroke to the forward stroke too quickly, which can cause the cycle of the action to operate too quickly. If the cycle of the action is too quick, the next round may not be properly gathered and loaded into battery condition by the bolt carrier 215. The magnetic dead-blow biasing mechanism 460 might be setup to achieve the dead-blow condition at the beginning of the rearward stroke when too much barrel gas is used to initiate the rearward stroke. In this situation, referred to as “overgassed,” the bolt carrier 215 jolts rearwardly too suddenly with the buffer 240, resulting in the bolt carrier 215 and the buffer 240 accelerating so quickly in the rearward direction that the bolt carrier 215 and the buffer 240 rebound off the rear end 220b of the buffer tube 220. The magnetic dead-blow biasing mechanism 460 may be set up to achieve the dead-blow condition at both the end and beginning of the rearward stroke when the action is slightly oversprung and overgassed.
One factor that must be considered when designing the magnetic dead-blow biasing mechanism 460 is a delay interval. The delay interval is the time it is expected to take for the weights 420, 421 to overcome the bias of the magnetic dead-blow biasing mechanism 460 and come to a dead-blow condition after an inertial event has occurred. Inertial events include the buffer 240 suddenly ceasing movement after being in motion and when the buffer 240 suddenly goes into motion from an at-rest position. Examples of inertial events arising from the buffer 240 suddenly ceasing movement include: (i) the buffer 240 striking the rear end 220b of the buffer tube 220 at the end of the rearward stroke; (ii) the buffer 240 striking the bolt carrier 215 during an initial period of the forward stroke if the buffer 240 and bolt carrier 215 become separated; and (iii) the bolt carrier 215 reaching the battery condition at the end of the forward stroke. Examples of inertial events arising from the buffer 240 suddenly going into motion include: (i) the start of the rearward stroke under the influence of barrel gases (by direct impingement or through a piston); and (ii) the start of the forward stroke under the influence of the action spring 230. The delay interval should be set to properly time the impact of the weights 420, 421 in the buffer 240 to offset a rebound 240 of the buffer 240 or to slow down an acceleration of the buffer 240.
An impact force provided by the weights 420, 421 after a delay interval reduces, minimizes, or eliminates bounce or rebound of the buffer 240 or slows down an acceleration of the buffer 240 after an inertial event. This effect is similar to the effect of a dead-blow hammer. For convenience, the dead-blow hammer effect just described is encompassed in the shorthand phrase “offset an inertial event.” To achieve the dead-blow hammer effect to offset an inertial event of the buffer 240 for desirable firearm 100 operation, the delay interval and the impact force must be fine-tuned. The proper combination of delay interval and impact force results in desirable operation of the firearm, and the delay interval and impact force that create this combination can be referred to as minimizing delay interval and minimizing impact force respectively. If these variables are not fine-tuned, the inertial event of the buffer 240 will not be offset.
For example, if the delay interval is too short, the weights 420, 421 will cause the impact force too soon after an inertial event. In this situation, the impact force does not create a dead-blow effect, but instead amplifies bounce or fails to slow down acceleration. Alternatively, if the delay interval is too long, the weights 420, 421 will cause the impact force too late after the inertial event. In this scenario, the impact force occurs after the buffer 240 has already bounced and the buffer 240 bounces for a second time during the same stroke. In addition, if the impact force provided by the front and rear weights is too small it will not sufficiently cancel out the bounce of the buffer. If the impact force of the weights is too great it will more than cancel out the bounce of the buffer and the excess impact force will cause bounce.
To fine tune the delay interval and impact force such that the inertial event is at least partially offset, the inertial event must be evaluated for relevant parameters. Relevant parameters include at least the acceleration of the buffer 240 and the bolt carrier 215, as well as the length of time over which the inertial event takes place. Using these parameters, the required minimizing delay interval and minimizing impact force for offsetting the inertial event can be determined. The properties of components of the firearm can then be adjusted so that the firearm assembly operates with the minimizing delay interval and the minimizing impact force required for desirable firearm operation.
The delay interval and the impact force are functions of multiple factors, including at least: the mass of the weights 420, 421; the travel distance between at-rest condition and dead-blow condition; friction; and strength (e.g., magnitude) of the magnetic force of the magnets 450a, 450b. The magnitude of the magnetic force of the magnets 450a, 450b is generally a function of: (i) the permeability of space between the first and second magnets 450a, 450b; (ii) the magnetic field strength of the first and second magnets 450a, 450b; (iii) a length of a face-to-face distance between the first and second magnets 450a, 450b; and (iv) geometry of the first and second magnets 450a, 450b.
In all the embodiments, the material of an encapsulation 440 may be changed, in the embodiment illustrated in
The geometry of the first and second magnets 450a, 450b may also be changed to alter the magnetic force. Also, the face-to-face distance between the first and second magnets 450a, 450b at the rearward-inertia condition and the forward-inertia condition may be altered by changing the length of some or all of the weights 420, 421, the length of some or all of the spacers 430, the thickness of the encapsulation 440, and/or the distance that the rear end cap 290 extends into the buffer cavity 270c of the buffer 240. Altering the face-to-face distance adjusts both the initial starting magnetic force exerted between the first and second magnets 450a, 450b, as well as the way in which the magnetic force is exerted between the first and second magnets 450a, 450b over time. Altering any of the variables of which the magnetic force is a function, either alone or in combination, may change the magnitude of the magnetic force. By changing the magnitude of the magnetic force, the delay interval and the impact force are also changed, and may be adjusted to achieve the desired minimizing delay interval and minimizing impact force.
Turning now to the illustrated embodiments,
The internal assembly 410 operates as follows. The internal assembly 410 is in the at-rest condition (
The internal assembly 610 operates as follows. The internal assembly 610 is in the at-rest condition (
In the embodiments illustrated in
The bolt carrier 215 therefore remains biased towards the front end cap 280 of the buffer 240 over the entire course of a firing action of a firearm. When an inertial event occurs at the end of a rearward stroke, the bolt carrier 215 remains biased towards (magnetically coupled to) the buffer 240 such that any bounce not offset by the resiliency of the rear end cap 290 and resilient spacers 430 in the buffer 240 is overcome by the magnetic attraction to further reduce or eliminate bounce of the bolt carrier 215 off of the buffer 240 (i.e., physical separation of the bolt carrier 215 from contact with the buffer 240). Additionally, the bolt carrier 215 remains biased towards the buffer 240 during an inertial event at the end of a forward stroke. The magnetic attracting force acts together with the weights 420, 421 coming to a dead-blow condition to bias the buffer 240 towards the bolt carrier 215 to further offset the inertial event and further reduce the bounce of the buffer 240 off of the bolt carrier 215. In some embodiments, the magnetic attracting force between the bolt carrier 215 and buffer 240 may be sufficiently strong to maintain engagement between the bolt carrier 215 and the buffer 240 during the entire firing and reloading action of the firearm. Additionally, the strength of the magnetic dead-blow biasing mechanism 460 enables a resilient spacers 430 to be positioned in the space between the two magnets 450a, 450b to reduce noise.
The internal assembly 1010 operates as follows. The internal assembly 1010 is in an at-rest condition (
Turning to
With reference now to
Depending on the magnitude and acceleration of the beginning of the forward and rearward strokes, the biasing force of the magnetic biasing mechanism 460 can be overcome to move the weights 420, 421 into the first and second dead-blow conditions of
Because only half of the plurality of weights 420, 421 in the embodiments of
Thus, the invention provides, among other things, a buffer assembly that includes at least one magnet that offsets an inertial event that occurs during the firing action of a firearm. The magnet thereby reduces, minimizes, or eliminates bounce or rebound of the buffer at the rear end of the buffer tube and/or at the bolt carrier. Various features and advantages of the invention are set forth in the following claims.
Number | Name | Date | Kind |
---|---|---|---|
2831404 | Sampson | Apr 1958 | A |
3366011 | Sturtevant | Jan 1968 | A |
3405470 | Wesemann | Oct 1968 | A |
5279202 | Bellardi | Jan 1994 | A |
5726377 | Harris | Mar 1998 | A |
6684549 | Bragg | Feb 2004 | B2 |
6829974 | Gwinn, Jr. | Dec 2004 | B1 |
7131367 | Boerschig | Nov 2006 | B1 |
7478495 | Alzamora | Jan 2009 | B1 |
7827722 | Davies | Nov 2010 | B1 |
8051593 | Vesligai | Nov 2011 | B2 |
8296984 | Kincel | Oct 2012 | B2 |
8430015 | Faifer | Apr 2013 | B2 |
8943726 | Kincel | Feb 2015 | B2 |
9080823 | Mantas | Jul 2015 | B1 |
9103611 | Neitzling | Aug 2015 | B2 |
9341437 | Huang | May 2016 | B1 |
9739566 | Huang | Aug 2017 | B2 |
9829260 | Geissele | Nov 2017 | B2 |
9879930 | Cassels | Jan 2018 | B2 |
9915492 | Huang | Mar 2018 | B2 |
9921013 | Oglesby | Mar 2018 | B1 |
9970722 | Babb | May 2018 | B1 |
9995553 | Oglesby | Jun 2018 | B1 |
10054378 | Pawlowski | Aug 2018 | B2 |
10088266 | Fournerat | Oct 2018 | B1 |
10415907 | Kincel | Sep 2019 | B1 |
10488129 | Myers | Nov 2019 | B2 |
10557674 | Mantas | Feb 2020 | B1 |
10619956 | Zhang | Apr 2020 | B1 |
10712108 | Cozad | Jul 2020 | B2 |
10852083 | Underwood | Dec 2020 | B2 |
10982918 | Newberry | Apr 2021 | B2 |
20020178901 | Bergstrom | Dec 2002 | A1 |
20030154640 | Bragg | Aug 2003 | A1 |
20060048637 | Dimitrios | Mar 2006 | A1 |
20060236853 | Boersching | Oct 2006 | A1 |
20080110074 | Bucholtz | May 2008 | A1 |
20100050492 | Faifer | Mar 2010 | A1 |
20100122482 | Simms | May 2010 | A1 |
20100251587 | Kincel | Oct 2010 | A1 |
20100251588 | Kincel | Oct 2010 | A1 |
20110000363 | More | Jan 2011 | A1 |
20110239852 | Kirstein | Oct 2011 | A1 |
20130192114 | Christenson | Aug 2013 | A1 |
20130316308 | Monti | Nov 2013 | A1 |
20130319217 | Gangl | Dec 2013 | A1 |
20140075798 | Kincel | Mar 2014 | A1 |
20140224112 | Verry | Aug 2014 | A1 |
20150226507 | Palmer | Aug 2015 | A1 |
20180087864 | Lowrance | Mar 2018 | A1 |
20190017765 | Bender | Jan 2019 | A1 |
20190353447 | Palenik, II | Nov 2019 | A1 |
20210025665 | Kincel | Jan 2021 | A1 |
20210025669 | Griffin | Jan 2021 | A1 |
20210164742 | Snyder | Jun 2021 | A1 |
Entry |
---|
TFB TV, “New Products of VLTOR Weapons Systems”, website: https://www.thefirearmblog.com/blog/2019/01/28/shot-2019-new-products-of-vltor-weapon-systems/, Jan. 28, 2019. |
NRA Shooting Illustrated, “First Look: ODIN Works AR-15 Adjustable Buffer Set” website: https://www.shootingillustrated.com/articles/2019/5/30/first-look-odin-works-ar-15-adjustable-buffer-set/, May 30, 2019. |
TFB TV, “Strike Industries OPTIMUS Modular Weight Buffer”, website: https://www.thefirearmblog.com/blog/2019/09/12/strike-industries-optimus-modular-weight-buffer/, Sep. 12, 2019. |
Number | Date | Country | |
---|---|---|---|
20210025665 A1 | Jan 2021 | US |