US3744370A

US3744370A - Blank firing attachment

Info

Publication number: US3744370A
Application number: US00120150A
Authority: US
Inventors: R Snodgrass
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1970-03-02
Filing date: 1970-03-02
Publication date: 1973-07-10
Anticipated expiration: 1990-07-10

Abstract

An improved blank firing attachment is provided for automatic weapons comprising a frame with a rod-like restrictor adjustably mounted on the frame. The frame utilizes slotted means for engaging cooperating slots or shoulders associated with the muzzle end of the barrel. The restrictor is adjusted to bear against the end of the barrel to close the bore. An axial bore in the restrictor of smaller diameter than the barrel bore offers interference to a projectile inadvertently fired minimizing danger to personnel in the area. The restrictor bore is vented to gradually reduce gas pressures therein and in the barrel bore.

Description

te States Paten 11 1 1 1 3,744,370 Snodgrass 1451 July 10,1973

[ BLANK FIRING ATTACHMENT Prima ExaminerSte hen C. Bentle 75 1 t Robert E. 511 11 D t, P Y 1 men or Iowa 0 grass avenpor Attorney-Harry M. Saragovitz, Edward J. Kelly,

Herbert Beal and Albert E. Arnold, Jr. [73] Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC. 57 ABSTRACT [22] Filed 1970 An improved blank firing attachment is provided for [2l] Appl. No.: 120,150 automatic weapons comprising a frame with a rod-like restrictor adjustably mounted on the frame. The frame utilizes slotted means for engaging cooperating slots or 3. 4 7 shoulders associated with the muzzle end of the barrel. Fie'ld 89/14 14 E 3 The restrictor is adjusted to bear against the end of the e h barrel to close the bore. An axial bore in the restrictor of smaller diameter than the barrel bore offers interference to a projectile inadvertently fired minimizing dan- [56] References Clted ger to personnel in the area. The restrictor bore is UNITED STATES PATENTS vented to gradually reduce gas pressures therein and in 3,440,924 4/1969 Sawyer 89/14 E the barrel bore.

FOREIGN PATENTS OR APPLICATIONS 3 Cl 5 D F 1,255,451 1/1961 France 89/14 E rawmg gums in km whw mm I I I6 I BLANK FIRING ATTACHMENT BACKGROUND OF THE INVENTION The present invention relates to an apparatus useful to simulate actual firing conditions for weapons, and more particularly to a blank firing attachment for such weapons.

In the art of automatic weapons, reliance is made upon utilizing gas pressures within the barrel incident to firing a round of ammunition thereby to effect automatic operation of the weapon, in a manner wellknown in the art.

During training operations, the use of blank ammunition is required for obvious reasons. However, in order to simulate actual combat conditions, provision must be made to effect automatic operation of a weapon using blank ammunition. For this purpose, a blank firing attachment is affixed to the muzzle end of the barrel thereby to utilize gas pressures incident to firing blank cartridges and produce automatic operation of the weapon. Prior art attachments of this kind have been found objectionable for various reasons. More specifically, one of the requirements is safety to personnel in the immediate vicinity. In the event a live round of ammunition should be fired inadvertently, the blank firing attachment is capable of being propelled down range sufficiently to become potentially dangerous. Other attachments are designed to insert the restrictor component within the bore of the barrel. Such arrangements are conducive to barrel wear and damage as a result of continued use due to a relatively loose fit and vibration as well as contributing to barrel damage if a live round is fired without first removing the attachment.

Accordingly, it is a primary object of the present invention to provide an improved blank firing attahcment which is more efficient and will conform to maximum safety standards.

It is a further object of the present invention to pro vide an efficient blank firing attachment which is universally applicable to automatic weapons for simulation of firing live rounds of ammunition.

It is also an object of the present invention to provide an improved blank firing attachment for automatic weapons which will minimize damage to the weapons in the event a live round is fired inadvertently without first removing the attachment.

Another object of the present invention is to provide an improved blank firing attachment which is easily applied to and removed from a weapon.

Still another object of the present invention is to pro vide a blank firing attachment for automatic weapons which is of simple structure, conducive to mass production, and yet is relatively inexpensive to manufacture.

SUMMARY OF THE INVENTION In accordance with the present invention, a blank firing attachment is provided for weapons which comprises a frame having means at one end for cooperation with means on the muzzle end of the weapon barrel for retaining it on the barrel. A restrictor carried by the opposite end of the frame is axially aligned with the barrel bore and adjustable for engagement with the muzzle end thereby to close the bore. The restrictor is provided with an axial bore of smaller diameter than the barrel bore and a vent which connects the axial bore with the ambient. The parts are arranged symmetrically and diametrically balanced with respect to the barrel bore axis to minimize damage to the barrel and facilitate removal in the event a live round is fired in the weapon without first removing the attachment.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features characteristic of the present invention, as well as additional objects and advantages thereof, will be understood better from the following description when read in connection with the accompanying drawings, in which:

FIG. I is a perspective view of a preferred embodiment of the present invention as applied to the muzzle end of a rifle barrel;

FIG. 2 is a perspective view of the blank firing attachment shown in FIG. 1; H 7,

FIG. 3 is an axial cross section of the parts shown in FIG. 1;

FIG. 4 is an exploded view of the parts shown in FIG. 1; and

FIG. 5 is an exploded view of an alternate embodiment of the body or frame of a blank firing attachment in accordance with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring more particularly to the drawings, wherein similar reference characters have been used to designate corresponding parts throughout, there is shown, in FIGS. 1 through 4, a preferred embodiment of blank firing attachment 1 in accordance with the present invention.

The attachment 1 comprises a base member 4, the body of which is a rectangular frame. At one end 5, a U-shaped opening extends inwardly to provide shoulders 7 for engaging an annular recess 9 associated with the muzzle end of rifle barrel 11. In the drawings, the annular recess is shown provided on a flash suppressor l3 threadedly engaged with the muzzle end of the barrel 11. The flash suppressor is of any suitable kind and is provided with a hollow interior and functions in a manner well-known in the art.

At the opposite end 15 of the frame a rod-like restrictor 16 is threadedly mounted to extend therethrough in symmetrical arrangement with the frame. Any suitable means for mounting the restrictor may be provided to effect rigidity, such as the threaded, flanged insert 17 shown particularly in FIGS. 3 and 4. The restrictor 16 is of a length at least coextensive with the length of the frame end to end. It is provided with an enlarged head 19 at the end thereof which extends into the frame. The diameter of the head is greater than the diameter of the barrel bore in order to provide a closure therefor. The shank surface of the restrictor is smooth beyond the head, except for a threaded portion 21 at the opposite end. The length of the threaded portion is preferably to an extent to firmly engage the head portion with the muzzle end of the rifle barrel thus, as the threaded portion is withdrawn from the frame threaded mounting means, the restrictor will slide freely along the smooth shank portion.

The restrictor is also provided with an axial bore 23 extending inwardly from the head. The bore is of a dimaeter less than that of the barrel bore thereby to offer interference to a projectile from a live round fired inadvertently. Thus, the interference has a tendency not only to dissipate the projectile energy thereby reducing danger to personnel in the vicinity, but also to reduce damage to the weapon.

At the head end of the bore, it is flared outwardly at least coextensive with the flared end of the barrel bore. At its inner end, a vent 25 is provided radially through the shank to relieve gas pressures within the restrictor and barrel bores. In order to facilitate adjustment and attachment of the restrictor on a rifle barrel, the threaded portion 21 is provided with a pin 27 diametrically through and adjacent to its outer end In accordance with a second embodiment of the present invention, the body or frame member 3 is provided with pivotal sides 29. The sides 29 are pivoted to the forward end 31, which carries the restrictor 16, in any suitable manner, such as the hinged arrangement 33 shown in FIG. of the drawing. With this arrangement, there is no necessity for the U-shaped opening such as that shown in FIGS. 1 through 4, instead each of the sides 29 is provided with a semicircular opening 35 facing inwardly toward the axis so that the suppressor engaging ends 37 completely encompass the circumferential slot of the suppressor.

Application of these attachments to a rifle barrel supplied with a slotted flash suppressor, or the like, is accomplished by withdrawing the restrictor 16 from the frame 3 to a maximum limit. The first described em bodiment shown in FIGS. 1 through 4 is attached by sliding the U-shaped opening 7 laterally into one of the suppressor slots or grooves. The second emodiment is attached by pivoting the sides 29 outwardly and then inwardly to engage the suppressor slot or groove. In both embodiments the restrictor is then axially inserted through thesuppressor and brought axially into abutment with the muzzle end of the rifle barrel. By turning the frame or the restrictor relative to each other the at tachment is then securely fastened to the barrel with the head end in abutment with the muzzle end thereby to close the barrel bore and restrict or confine expanding gasses incident to firing blank cartridges within the barrel whereby the pressures are utilized to effect automatic operation of the rifle in a manner well-known in the art.

It will be recognized by persons skilled in the art that the present invention provides a blank firing attachment which is easily applied and the structure of which is symmetrically balanced about the rifle bore axis. The symmetrical arangement is conducive to equalizing forces in the framework which are generated by a projectile of a live round being fired inadvertently without first removing the attachment. This arrangement minimizes damage to the barrel because no part of the attachment lies within the barrel bore and if the projec tile expands or elongates the attachment frame, it can easily fall from the weapon primarily by its own weight. On the other hand, the attachment being provided with a radially extending vent 25, if the operator orients the vent upwardly, the expanding gasses exiting through this vent will have a tendency to minimize climb of the rifle during sustained automatic operation.

Although but two preferred embodiments of the present invention are shown and described herein it will also become obvious to persons skilled in the art that other forms thereof, as well as changes in the particular forms described, are possible within the spirit and scope of the present invention. Therefore, it is desired that the present invention shall not be limited except insofar as it is made necessary by the prior art and by the spirit of the appended claims.

I claim:

1. A blank firing attachment for a rifle barrel comprising a rectangular frame, a rod adjustably mounted on one end of said frame for movement toward and away from an opposite end of said frame, one end of said rod being at least coextensive with said barrel bore diameter and being freely disposed within said frame, said one end having an axial bore terminating inwardly thereof from said one end, said frame being disposed substantially symmetrical about the axis of said rod, said frame opposite end being provided with slotted means for engaging cooperating means associated with the muzzle end of said barrel, whereby said rod one end is adapted for abutment with the end of said barrel in a manner to close the bore thereof.

2. The invention as defined in claim 1 and wherein said rod is provided with vent means disposed radially outwardly from said axial bore for communicating said axial bore with the ambience;

3. The invention as defined in claim 2 wherein the sides of said frame are pivotally attached to said one end for movement toward and away from each other, and said opposite end is bifurcated symmetrically with respect to said slotted means.