This nonprovisional application claims priority based upon the following prior United States Provisional Patent Application entitled: Low Friction Bolt Carrier, Application No. 62/053,396 filed Sep. 22, 2014, in the name of Jason Adams and Carmelo Russo, which is hereby incorporated by reference for all purposes.
The present invention relates generally to firearms, more specifically but not by way of limitation, firearm components that slidably move during the operation of a firearm and further wherein the firearm components of the present invention are constructed so as to reduce the friction during the sliding movement thereof.
Automatic and semiautomatic rifles, including firearms based on the AR-15 service rifle and similar platforms, use impingement mechanisms to automatically reload. Capturing energy from fired ammunition to reload is typically accomplished using either direct impingement, i.e., porting pressurized gas from the barrel through a gas key to act directly on a bolt carrier, or using a piston system, in which gas drives a piston that impinges on an integral key on the bolt carrier. Both of these systems cause a piston-like action of the bolt carrier in the rifle's upper receiver, and in either case, repeated travel of the bolt carrier within the upper receiver coordinates cycling of the action which is inclusive of unlocking the bolt, ejecting the spent cartridge, chambering a new round, and so forth.
Ensuring a continuous and reliable automatic reloading operation during rapid firing over time requires that the bolt carrier travel smoothly in the upper receiver. Bolt carriers and upper receivers presently known in the art rely principally on precision milling or machining to produce a fit that adequately constrains the bolt carrier while providing adequate freedom of the back-and-forth movement. Despite a substantially complimentary fit, both the bolt carrier and upper receiver eventually suffer damage caused by sliding contact over prolonged periods of repeated firing. Heat buildup caused by friction is also a concern.
Direct impingement mechanisms are increasing disfavored due to a tendency to cause gas fouling. Over time, as carbon-laden gasses travel through the bolt carrier, the risk of a malfunction increases. Because automatic and semiautomatic rifles are often built on a common platform customarily employing standardized interchangeable parts, and due to the increasing preference for piston driven systems, users frequently customize firearms with newly developed aftermarket alternative components. These modifications occasionally result in a slightly imprecise fit between the bolt carrier and upper receiver, compounding existing friction-related problems and accelerating damage to the reloading mechanism.
Other components within firearms that perform repeated sliding movement and rely on precise machining include but are not limited to shotgun shell followers. As is known in the art, shotgun shell followers are operably coupled to a spring in the magazine tube of a shotgun and are operable to slidably move within the magazine tube and engage the shotgun shell adjacent thereto during the loading and firing process. The movement of the shotgun shell follower impacts performance of the firearm during the loading and firing process.
Due to the problems in the art, there is a need for improved firearm components such as but not limited to a bolt carrier and shotgun shell follower that avoids excessive friction from sliding movement during use of the firearm. There is also a need for a bolt carrier and shotgun shell follower capable of assembly as part of customizing or retrofitting a firearm. Additionally, it is desired for a bolt carrier and shotgun shell follower that are formed from a single piece of material, making it simple and inexpensive to mass produce.
It is the object of the present invention to provide firearm components that exhibit significantly reduced friction between themselves and adjacent firearm elements during the slidable movement thereof.
Another object of the present invention is to provide firearm components such as but not limited to bolt carriers and shotgun shell followers that include at least two diametrically opposed channels on the cylindrical bodies thereof.
A further object of the present invention is to provide firearm components that exhibit reduced friction between themselves and adjacent firearm elements wherein a plurality of ball bearings are releasably secured in the at least two diametrically opposed channels.
An additional object of the present invention is to provide firearm components such as but not limited to bolt carriers and shotgun shell followers that include at least two diametrically opposed channels with ball bearings therein that further include a retainer proximate an end of each channel.
Yet a further object of the present invention is to provide firearm components that exhibit significantly reduced friction between themselves and adjacent elements thereto that can be incorporated into an assembly or retrofit package for a particular firearm.
To the accomplishment of the above and related objects the present invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact that the drawings are illustrative only. Variations are contemplated as being a part of the present invention, limited only by the scope of the claims.
A more complete understanding of the present invention may be had by reference to the following Detailed Description and appended claims when taken in conjunction with the accompanying Drawings wherein:
Referring now to the drawings submitted herewith, wherein various elements depicted therein are not necessarily drawn to scale and wherein through the views and figures like elements are referenced with identical reference numerals, there is illustrated a reduced friction firearm component 100 constructed according to the principles of the present invention.
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The shotgun shell follower embodiment 50 is manufactured from a suitable durable material such as but not limited to metal. Wall 60 is integrally formed with bottom 65 utilizing suitable durable techniques. The wall 60 is cylindrical in shape so as to mateably engage with the magazine tube 95. Formed on the exterior surface 61 of the wall 60 are slots 24. The slots 24 are formed in a similar manner as the slots 24 on the low friction bolt carrier embodiment 10. The slots 24 have a first end 77 and second end 78 with end 77 having opening 79 and being proximate the upper edge 88 or lower edge 89. The slots 24 are circumferentially disposed on wall 60. The illustrated configuration of the slots 24 provides desired distribution of contact between the bearings 22 and the inner surface 97 of the magazine tube. Bearings 22 are mounted within slots 24 of the shotgun shell follower embodiment 50 in the same manner as the low friction bolt carrier embodiment 10. The bearings 22 are rotatable within slots 24 and are mounted such that the surface of the bearings 22 extends outward from the wall 60 and provides the only point of contact with inner surface 97. Advantages to this configuration provide a shotgun shell follower embodiment 50 that has improved balance within the magazine tube 95 and creates less friction therewith. While a plurality of slots 24 are illustrated herein, it is contemplated within the scope of the present invention that the slots 24 could be formed in the wall 60 with various spacing profiles. It is further contemplated within the scope of the present invention that the shotgun shell follower embodiment 50 could have as few as two slots 24 diametrically opposite on wall 60 provided a keeper or other similar device restricted the movement of the shotgun shell follower embodiment 50 specifically reducing any lateral movement within the magazine tube 95. While not illustrated on the shotgun shell follower embodiment 50, plugs 26 are utilized to secure bearings 22 within slots 24 of the shotgun shell follower embodiment 50 in the same manner as the low friction bolt carrier embodiment 10.
In the preceding detailed description, reference has been made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments, and certain variants thereof, have been described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that other suitable embodiments may be utilized and that logical changes may be made without departing from the spirit or scope of the invention. The description may omit certain information known to those skilled in the art. The preceding detailed description is, therefore, not intended to be limited to the specific forms set forth herein, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents, as can be reasonably included within the spirit and scope of the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
1365355 | Thompson | Jan 1921 | A |
3636648 | Spencer | Jan 1972 | A |
3742638 | Archer | Jul 1973 | A |
3951126 | Rau | Apr 1976 | A |
4524671 | Bender | Jun 1985 | A |
6200225 | Hobaugh, II | Mar 2001 | B1 |