Gun Recoil Reducer

1. Field of the Invention

The invention relates to firearms and particularly to a recoil reducing device for use with shoulder-fired firearms.

2. The Prior Art

The provision of inertia-type recoil reducers has been previously suggested but such previous devices have generally embodied a cylinder slidably mounting a spring-loaded weight or piston, such as the devices disclosed in R. L. Shockey U.S. Pat. No. 2,627,686; S. C. Baker U.S. Pat. No. 3,300,889; J. B. Edwards U.S. Pat. No. 3,381,405; F. Wesemann U.S. Pat. No. 3,405,470; and I. D. Vironda U.S. Pat. No. 3,461,589. R. E. Bennett U.S. Pat. No. 3,335,515 discloses an anti-recoil device for guns comprising a single chamber cylinder inserted in the stock from its butt end and partly filled with mercury so as to utilize the impingement of the mercury against the forward wall of the cylinder during recoil, due to inertia of the mercury to dampen recoil.

The invention provides an improved means for reducing recoil of a gun by the reaction of a heavy liquid such as mercury in a sealed container against rearwardly-moving surfaces of the gun-mounted sealed container as the gun moves rearwardly in recoil.

The effectiveness of the device to reduce recoil is increased by dividing the container into three chambers by a pair of transverse bulkhead partitions, each formed with a small orifice, so that the mercury reacts against the rear surface of the bulkhead as well as against the front wall of the container during recoil, and the restricted orifices retard the passage of the mercury from the rear chamber to the forward chamber.

The effectiveness of the device to reduce recoil is also enhanced by mounting the device on the gun with its rear end lower than its forward end, such that normally the liquid is substantially out of engagement with the forward wall of the device, whereby during rearward movement of the gun in recoil substantially the entire cross section of the liquid is brought into reactive engagement with rearwardly facing transverse wall surfaces of the device rather than merely a part of the cross sectional area of the liquid, as would be the case if the device were mounted in the gun in a normally horizontal position.

The inclined mounting of the device in the gun facilitates return of the liquid to its normal ready position with the rear and middle chambers full and the forward chamber only partly filled.

Auxiliary orifice means through the partition permits the passage of entrapped air between the forward to rear ends of the device and this facilitates the passage of mercury from end to end of the device during and after recoil.

FIG. 1 is a side elevational view partially sectionalized of a shoulder-held firearm equipped with a recoil reducing device constructed in accordance with the invention.

FIG. 2 is an enlarged longitudinal diametral sectional view of the recoil reducing device taken along line 2--2 of FIG. 3.

FIG. 3 is a transverse sectional view of the recoil reducing device taken along line 3--3 of FIG. 2.

FIG. 4 is a three dimensional view of the plug used in the device to form a central partition dividing the device into two chambers.

FIG. 5 is a longitudinal diametral sectional view of the device taken along lines 5--5 of FIGS. 2 and 3.

The numeral 1 indicates the stock of a trap gun 3. The stock is formed with the usual draw bolt hole 5 extending forwardly from the butt and parallel to the lower edge of the stock, thus being inclined downwardly and rearwardly with respect to the axis of barrel 9. Substantially forwardly of the butt, head 11 of the draw bolt 13 is seated on a shoulder formed in the draw bolt hole.

The recoil reducing device of the present invention, generally indicated at 15 in FIG. 1, is inserted in the draw bolt hole with its forward end against draw bolt head 11 and is held against axial shifting in the draw bolt hole by a dowel 17 extending rearwardly from the rear end of the reducing device 15 to the rear end of the draw bolt hole 5 where it abuts butt plate 19 which is secured to the stock by screws 21.

The recoil reducer comprises a hollow cylinder 23, the rear end of which has a reduced outer diameter as at 25, the forward end of which is of suitable diameter for slidable reception in draw bolt hole 5.

Cylinder 23 is sealed at its rear end by a screw plug 27 and is provided intermediate its ends with a partition formed from a fixed cylindrical plug 29 dividing cylinder 23 into a rear chamber 31 and a forward chamber 33, and partially cut away intermediate its ends to form a middle chamber 32 and forward and rear bulkheads 34 and 36. Central orifices 35 and 38 of substantially less diameter than chambers 31 and 33 extend through bulkheads 34 and 36 to connect chambers 31,32 and 33, and the cylinder is partly (preferably about two-thirds) filled with mercury L, or with a liquid having similar characteristics and specific gravity, such that when the device 15 is secured in the draw bolt hole 5 as shown in FIGS. 1 and 5, as described above, the rear chamber 31 will be full of mercury and the middle and forward chambers will be only partly filled. Thus, when the gun is fired the inertia of the mercury will cause the mercury mass to remain substantially stationary, even though the entire gun moves rearwardly on recoil. As the gun, and with it cylinder 15, moves rearwardly, the substantially stationary mercury in rear chamber 31 reacts against bulkhead 34 and some of the mercury in rear chamber 31 is forced through orifice 35 into central chamber 32 where it reacts against bulkhead 36, thence through orifice 38 into forward chamber 33 where it reacts against the forward wall of the cylinder. The retardation effect of the reduced cross sectional area of orifices 35 and 38 on the flow of mercury during the rearward movement of the cylinder combines with the reaction of the mercury on the plug bulkheads and forward wall of the cylinder to absorb much of the recoil energy and reduce the recoil impact. During rearward movement of the gun and cylinder 23 during recoil, the air above the mercury in the forward and middle chambers is permitted to pass to the rear chamber through a shallow passageway 39 formed between a flat 37 on plug 29 and the inner surface of the cylinder, so that the full mass of the mercury can react against the forward surfaces of chambers 33 and 32, passageway 39 being connected to chamber 32 by lateral passage 41.

After each firing of the gun, the mercury returns to its normal condition by gravity principally by means of orifices 35 and 38 wherein it fills rear chamber 31 and only partly fills middle chamber 32 and forward chamber 33, as best seen in FIG. 5. Such return flow of the mercury is expedited by the return of the entrapped air, which had passed from the forward to the rear chamber during recoil via shallow passageway 39 and via lateral passageway 41 to the forward and middle chambers respectively.

The invention may be modified in various respects as will occur to those skilled in the art and the exclusive use of all such modifications as come within the scope of the appended claims is contemplated.