US 3246567 A
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Description (OCR text may contain errors)
April 19, 1966 A. MILLER 3,246,567
OPERATING ROD FOR SELF-LOADING FIREARM Filed June 15, 1964 United States Patent 3,246,567 OPERATING ROD FOR SELF-LOADING FIREARM Arthur Miller, Costa Mesa, Calif., assignor to Armaiite, Inc., Costa Mesa, Calif., a corporation of California Filed June 15, 1964, Ser. No. 375,256 Claims. (Cl. 89-191) This invention relates to an improvement in the conventional gas-actuated push rod system for a self-loading firearm, more particularly, to a push rod system particularly adapted to a lightweight, self-loading firearm of the rapid fire type.
In the conventional gas-actuated push rod system for a self-loading firearm, the gas is bled from a port in the barrel into a piston and cylinder arrangement.
It is preferred in the interest of less weight to locate the gas port on the barrel nearer the muzzle where the gas pressure is less and the unlocking and reloading can be effected with less massive mechanism than is required for storing the kinetic energy to effect reloading with a short-coupled gas system. However, a long and relatively rigid push rod is required in such a system. The rigid push rod is attached to the piston cylinder arrangement on one end and the other end is attached to the receiver mechanism in a manner to actuate the selfloading mechanism. It is spring-biased for the return stroke.
If the push rod is of reduced diameter to eliminate weight, it will bend or whip by reason of the rapid action of the firearm and in the conventional system, introduces binding or galling in the piston and cylinder assembly. The binding or galling of the piston and cylinder will cause malfunction or greatly reduce the effectiveness of the system.
In the present invention, the push rod can be of greatly reduced diameter from the conventional push rod and designed to bend freely within the elastic limits of the material without impairing the function of the weapon and thus effecting a considerable reduction in the weight of the push rod. This is accomplished by the mounting of the push rod on the piston assembly as hereinafter described.
It is an object of this invention to provide a lightweight push rod for a gas-actuated push rod system through the reduction of the diameter of the push rod which can bend freely in operation Without impairing the operation of the system or causing malfunction of the system.
It is another object of this invention to provide a mounting for a push rod for gas-actuated push rod system for a self-loading firearm that will bend freely without transmitting the bending of the push rod to the piston cylinder assembly.
Further and other objects of this invention will become apparent from the description of the accompanying drawings in which like numerals refer to like parts.
In the drawings:
FIG. 1 is a fragmentary view of a rapid self-loading firearm gas-actuated push rod system;
FIG. 2 is a fragmentary view of the forward end of the barrel of the system, showing the push rod assembly in the operating position;
FIGS. 3 and 4 are views of an alternate arrangement of the push rod piston cylinder assembly on a rifle barrel.
FIGURE 1 of the drawing shows a rifle barrel 1 secured to a receiver 2. Block 3 represents a portion of the self-loading system which is actuated by push rod 4. Push rod 4 extends into the receiver 2 and moves block 3, as the rifle is fired, for reloading.
On the forward end of barrel 1, gas is bled off at port 5 in the barrel and through passage 6. Piston 7 has passage 8 formed therein and it is threaded at 9 into bracket 10 which is rigidly secured to barrel 1. A cylinder 11 surrounds piston 7 and moves rearwardly of the barrel with each firing.
The forward end of push rod 4 is formed with a spherical surface engaging a similar spherical surface on cylinder 11. The forward end of push rod 4 and the rearward end of cylinder 11 have inter-engaging means, such as pin 13 loosely fitting in hole 14, to provide freedom of movement of push rod 4 with respect to cylinder 11 at surface 12. Spring 15 biases push rod 4 against cylinder 11 throughout the operation of the system.
When the rifle is fired and the bullet passes port 5, a small quantity of gas under high pressure is bled off through passages 6 and 8 and causes cylinder 11 to move rearwardly of the barrel of the rifie. The motion of cylinder 11 is transmitted to push rod 4, and in turn, to bolt unlocking and reloading mechanism represented at 3.
If rapid fire causes push rod 4 to bend or whip, the forward end will merely move with respect to cylinder 11 on spherical surface 12, and no bending or stress will occur between cylinder 11 and piston 7 that will tend to gall and produce malfunction.
As shown in FIG. 2, relative motion of piston 7 and cylinder 11 will be coaxial.
FIGS. 3 and 4 show the same result with a lightweight push rod, but with the connection of the piston and cylinder reversed. Piston 7' has formed on its rearward end, spherical surface 12 and projection 13. Cylinder 111 is threaded to engage bracket 10. The remainder of the parts function in the manner described in connection with FIGS. 1 and 2.
A long, lightweight push rod is thus achieved which will operate reliably over a long period of time and achieve the overall feature of saving in weight in the self-loading system including the unlocking and reloading mechanism.
It is to be undertsood that certain changes, alternations, modifications and substitutions can be made without departing from the spirit and scope of the appended claims.
What is claimed is:
1. A lightweight push rod system for a self-loading firearm comprising a barrel, a gas port formed therein near the muzzle end of said barrel, a piston and cylinder assembly secured to said barrel, means forming a passage to interconnect said piston and cylinder assembly and said gas port to conduct gas from said barrel to actuate said piston and cylinder assembly, said piston and cylinder assembly formed with a spherical end surface perpendicular to the axis of said assembly, a push rod interconnecting said piston and cylinder assembly and the self-loading mechanism of the firearm, said push rod having the end adjacent said piston and cylinder assembly formed with a mating spherical surface, loosely coupled locator means positioning said spherical end of said push rod on said spherical end of said piston and cylinder assembly and biasing means to hold said spherical surfaces in contact and to permit relative motion of said push rod along said barrel, but out of axial alignment with said piston and cylinder assembly, said locator means comprising an elongated pin on one of said spherical surfaces, loosely engaging a longer hole formed in the other of said spherical surfaces.
2. The device as set forth in claim 1, in which said means forming a passage interconnecting said piston and cylinder assembly and said gas port is a bracket firmly secured to said barrel, said piston and cylinder assembly being mounted on said bracket.
.3. The device as set forth in claim 1, in which said bracket is a front sight bracket.
3 4. The device as set forth in claim 1, in which the pis- References Cited by the Examiner ton of said piston and cylinder assembly is mounted on UNITED STATES PATENTS said bracket with the axis thereof extending generally aranel to the axis of said barrel 564,043 7/1896 Benet et al 89-191 X P 5 Th d f h 1 h h 5 1,524,974 2/1925 Hazelton s9 193 e evlce as Set on In C alnl 1 W t 5 3 0 9 97 1 2 Stevens 89-191 cylinder of said piston and cylinder assembly is mounted Y I on said bracket with the axis thereof extending generally BENJAMIN BORCFIELT Exammer' parallel to the axis of said barrel. FRED C. MATTERN, In, Examiner.