US 20050115134 A1
A shock absorber for use on the butt of the stock of a rifle, such as a shotgun, that absorbs significant recoil force by means of a foam construction formed to have plural air-trapping chambers in the base, which base is positioned between the butt of the stock of said rifle or shotgun and the shoulder of the user. As the foam base compresses, the air in the plurality of air-trapping chambers (areas compressed); delaying and limiting rearward travel of the force transfer of the stock to the shoulder of the user. Vent nozzle holes in the base allow the air trapped in these chambers to be vented but at the delayed and controlled rate to the outside of the device. Thus, the recoil is brought to a slowed stop as the increase in pressure of the air in the air-trapping chambers slows and eventually matches the rate at which air is vented outside the device through the vent holes.
1. A shock absorber for a rifle, as shown and described herein.
Non-provisional utility patent application claiming the benefit of Provisional Patent titled SHOCK ABSORBER FOR A RIFLE having U.S. application No. 60/517,185, and Filing Date of Nov. 04, 2003.
Certain rifles, such as shotguns, have a significant recoil or kick. When the trigger is pulled and the round of ammunition detonates, half of the kinetic energy released by the exploding gunpowder in the shell propels the bullet or shot forward through the barrel of the rifle and onward to the target. However, the other half of the kinetic energy goes in the opposite direction, rearward, and the rearward motion causes the force transfer to be absorbed largely by the user. For those who are unaccustomed to firing shotguns or who fire them a lot, the recoil can leave shoulders sore or bruised.
Accordingly, there is a need for a way to minimize the force transfer of the recoil of rifles such as shotguns. Several attempts have been made and some of these are the subjects of U.S. patents. See for example, U.S. Pat. No. 4,922,641, issued May 8, 1990, to Johnson, U.S. Pat. No. 4,551,937, issued on Nov. 12, 1985, to Seehase, and U.S. Pat. No. 5,375,360, issued Dec. 27, 1994, to Vatterott.
Nonetheless, there remains a need for a more effective way to absorb the kick, or force transfer of those rifles that have significant recoil.
According to its major aspects and briefly described, the present invention is a shock absorber for use with a rifle. The present shock absorber fits closely on the butt of the stock of a rifle and is made of foam. In addition to the impact-absorbing quality of the foam construction, the present device is shaped to trap a quantity of air inside air chambers, and release it through vent nozzles, thus using the compression bulge of the air and its delayed release as a way to prevent the immediate impact force transfer of momentum from stock to the shoulder of the user. By decreasing the force which the recoil transfers to the user, the impact is correspondingly reduced and, with it, the likelihood of injury or bruising. While no device can or will greatly arrest the rearward movement of the stock, the pain of recoil impact transfer can be significantly reduced and bruising negated.
The combination of foam construction, air-tapping chambers, and vent nozzle holes releasing said air are the features of the present invention. This combination allows the recoil kinetic energy to be managed and controlled so that it has less impact on the shoulder of the user.
The use of vent nozzle holes communicating from the chambers to the exterior of the device is another feature of the present invention. The vent nozzle holes prevent the pressure in the chamber from increasing sharply. As air pressure bulges the chamber construction during recoil, the vent nozzle holes allow compressed air to be released at a predetermined rate thus keeping the compressed air from transferring the recoil impact (force transfer) to the shoulder by the slow cushioning effect of air being vented as compression builds. The use of air venting is not a necessary by-product aiding springs, coils or other devices within cylinders; but a combination of air chambers, foam construction and nozzle release system working as one unit to produce a desired effect.
The one-piece moldable construction of the present device is another feature of it. By being configured in one simple piece, the present product is easier and cheaper to make. It is made of lightweight foam. Furthermore its shape allows the device to be fitted onto and easily removed from a rifle and transferred to another rifle if desired. It allows an owner of several rifles to own a set of the present shock absorbers at minimal expense, each one tuned to that particular user and rifle. While this one-piece construction is the preferred embodiment, the air chamber design will lend itself to a type construction that can be attached to a stock by screws or other fastening devices.
These and other features and their advantages will become readily apparent to those skilled in the art of rifle accessories from a careful reading of the following Detailed Description of Preferred Embodiments, accompanied by the drawings.
In the drawings,
The present invention is a shock absorber for use on a rifle, particularly shotguns and other rifles having a significant recoil kick.
The shock absorber according to the present invention and as illustrated in the accompanying drawings fits like a sleeve or cup over a portion of the stock of a rifle. The rifle of
Shock absorber 14 is made entirely of foam rubber, either synthetic or natural foam rubber, and preferably of neoprene (closed cell flexible) or urethane foam. It may be made in colors such as camouflage colors, hunter orange or in basic black. Because it is resilient, it may be slipped onto and off stock 12 easily just as it may be slipped off of a mold in manufacture. Also, said material may incorporate within material U.V. retardant and or other chemicals to keep said material from breaking down with time or losing elasticity due to sunlight, heat or water.
A cross sectional detailed view reveals shock absorber 14 to have a much thicker base 20, in the preferred embodiment than walls 22. Base 20 has plural air-trapping chambers 24 formed in it, also visible in
When rifle 10 is fired, the exterior surface 28 of base 20 is in position against the shoulder of the user.
When rifle 10 is fired, approximately half of the kinetic energy from the exploding round is directed rearward, resulting in movement of stock 12 rearward (to the right in
Initially the air-trapping chambers cannot be vented fast enough and pressure in air-trapping chambers 24 builds, thus limiting the further compression of the foam of base 20. As recoil compressed air bulges the typical air-trapping chambers 24 the rearward movement of stock 12 increases pressure in the air-trapping chambers and is eventually matched by the rate at which air 30 is vented through vent nozzle holes 26; allowing progressive release of additional compression or bulging of the foam of base 20. The rearward movement is slowed and allows the shock absorber to delay and absorb the recoil force over time rather than suddenly.
The recoil of a rifle is dependent on the type of rifle and to some degree, on the type of ammunition and or use of blow back recoil gases. Nonetheless, the present shock absorber can easily be engineered or tuned to the user and the rifle with modest rather than undue experimentation. Using neoprene or urethane foam for base 20 that is preferably one to two inches thick, with preferably three air-trapping chambers 24, each one having one vent nozzle hole 26 of ⅛th inches or smaller in diameter, reasonable shock absorbing quality is obtained. Increasing the thickness of base 20 reduces recoil, and by also increasing the inside diameter of air-trapping chambers 24 while decreasing the size of vent nozzle holes 26 adds to the shock absorbing effect. In some cases the vent nozzle holes may be eliminated and type foam material constructed thin enough to allow bulging to compensate the recoil.
Wall 22 can be sized to grip stock 12 firmly, such as approximately ¼ to ½ inch in thickness with an interior dimension approximately equal to that of the exterior dimensions of stock 12.
Those skilled in the art of firearm accessories will no doubt see that many substitutions and modifications can be made to the foregoing preferred embodiments without departing from the spirit and scope of the present invention, which is defined by the appended claims.