Barrel Ring And Associated Structure For Autoloading Firearms

Abstract

A barrel ring, which surrounds the magazine tube of an auto-loading firearm in an easy sliding fit, is provided with an extending tapered lip on its lower forward edge; a cap which is provided to close around the tube end at the barrel ring has a rim configurated to bear upon the inner surface of the lip as the cap is advanced toward the ring. In this fashion, the magazine tube is forced into tight contact with the upper inner surface of the ring.

Description

BACKGROUND OF THE INVENTION

1. Field

This invention relates to gas-operated autoloading firearms such as semiautomatic shotguns and, more particularly, to the structure of a magazine tube support ring and a cap associated therewith for such firearms.

2. State of the Art

In firearms of the autloading gas-operated type, and particularly in shotguns of that type with removable barrels, a hollow magazine tube is typically disposed beneath the barrel in parallelism thereto. The magazine tubes are generally of substantial length and have one end fixed to the receiver mechanism of the firearm while the other (forward) end is slidably received easily into a bracket which is permanently fixed to the barrel. The magazine tube, in turn, guides and supports the barrel by means of the bracket. The bracket is variously referred to as a barrel lug, a support ring or a barrel ring; essentially, such a bracket comprises a portion which is fixed to the barrel plus an extending annular member with a cylindrical inner surface to closely surround the magazine tube. A magazine cap is generally removably fitted to the forward end of the magazine tube to engage the forward face of the barrel ring. The cap thus both secures the assembly and closes the end of the magazine tube. When the cap is removed, the barrel may be detached from the receiver and slid off the magazine tube for facility of cleaning or carrying.

It is well known to provide a channel through the barrel ring which, in conjunction with connecting apertures through the barrel wall and through the magazine wall, interconnects the interior of the barrel with the interior of the magazine tube to provide a passage for tapping explosion gases from the barrel. The magazine tube then serves as an operating cylinder wherein is disposed a piston which is forced by the explosion gases to activate the reloading action of the firearm.

A problem with such arrangements has been the inevitable escape of gases where the barrel ring surrounds the magazine tube. The force of the explosion gases typically pushes the magazine tube down toward the bottom of the barrel ring and thus increases the space between the top of the magazine tube and the upper inner surface of the ring. Deposits od contaminates from the escaping gases eventually form in the space, making it difficult to slide the barrel ring along the magazine tube to dismount the barrel.

SUMMARY OF THE INVENTION

This invention provides a novel barrel ring and cooperating magazine cap structure to be utilized on an autoloading firearm. The barrel ring of this invention permits ease of withdrawal of a magazine tube therefrom. Nevertheless, while in assembled condition, the cap and ring provide a sealed fit with the magazine tube to prevent the escape of gases therebetween.

According to the invention, a modified barrel ring is provided where the lower forward edge of the ring has an integral projecting lip of tapering thickness and a cap is provided to close the magazine tube end so that, when the cap is secured around the end of the tube, the edge of the cap rides on the lip of the ring to push the tube against the upper inner surface of the ring thereby effecting a sealed fit to prevent leakage of tapped explosion gases.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be readily understood by referring to the following description and appended drawings, in which:

FIG. 1 is a sectional elevation of a barrel and magazine tube of an autoloading firearm illustrating the mechanism of the invention; and

FIG. 2 is a perspective view of the bracket shown in FIG. 1.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

In FIG. 1, a barrel 11 of an autoloading firearm is releasably secured at one end to a receiver (not shown) wherein is housed the action of the firearm. Mounted below the barrel is a combination magazine tube and operating cylinder designated 12 (hereinafter referred to only as a magazine tube) which also has one end secured to the receiver and which extends therefrom in alignment with the barrel. The magazine tube 12 houses the cartridges for the firearm and contains various well-known mechanisms, not here shown, to expel expended cartridge casings and to active reloading. As is conventional, the power for activating those mechanisms is generated by the hot firing gases which are released in the barrel by firing and which are directed therefrom into the magazine tube. In the illustrated embodiment, the magazine tube is a cylindrical chamber and has an aperture or gas port 13 formed in its wall through which the firing gases can flow.

As illustrated, the barrel is readily separable from the magazine tube; in other words, the firearm shown is of the type which may be easily and routinely taken down. Accordingly, a barrel ring 14 is provided which fixedly depends from the barrel 11 to slidably receive the magazine tub 12 therethrough. As best shown by FIG. 2, the barrel ring 14 is embodied as an annular member 14a permanently fixed to the barrel 11 by an integral lug portion 15, and the annular member 14a has a circular central aperture 16 through which the magazine tube 12 slidably fits.

The barrel ring 14 includes, as is conventional, conduit means for providing a gas path from the barrel to the interior in the magazine tube. In the illustrated embodiment, the conduit means comprises a channel 17 formed radially through the wall of the ring to interconnect apertures 18 and 13 formed in the barrel wall and magazine tube wall, respectively. Gases released in the barrel are thus tapped into the magazine tube to activate the mechanisms contained therein.

An integral lip 19 is formed along the lower portion of the forward edge of the barrel ring 14. The lip 19 describes an arc of less than 180.degree. along the lower circumferential edge of the ring and projects forward therefrom. In the illustrated embodiment, the lip is tapered to narrow away from the ring. In practice, a taper of about 30 .degree. from horizontal is satisfactory. The upper portion 15 of the barrel ring 14 in the illustrated embodiment has a rabbet 20 which is at a generally greater radius from the axis of the ring than the lip.

Further according to the invention, a cap 21 is provided to close around the end of the magazine tube adjacent the barrel ring; the cap has a rim portion 22 which engages the inner surface 19a of lip 19 on the barrel ring. As the cap is drawn (as by threading) on to the magazine tube end, the rim 22 rides up on the lip 19 to force the magazine tube toward the top of the central aperture of the ring to effect an interference seal between the top of the magazine tube and the inside surface of the ring around the juncture of the channel 17 and aperture 13. Consequently, firing gases are unable to escape between the magazine tube and the barrel ring. In the illustrated embodiment, the rim 22 of the cap 21 is beveled or rounded to generally match the taper of the lip 19. Consequently, a smooth wedging action is achieved as the cap 21 is advanced toward the ring 14.

In the illustrated embodiment the cap 21 is further provided with a circumferential flange 23 which contacts both the rabbeted portion 20 of lug 15 and the outer edge of the lip 19 so that the cap is positively stopped after the rim of the cap has ridden up a certain distance onto the lip.

While the invention has been described with respect to certain details of the illustrated embodiment, other arrangements may be utilized to wedge the magazine tube against the upper inner surface of the barrel ring as the cap is drawn onto the magazine tube. For example, either the lip 19 or the rim 22 of the cap 21 need not be tapered; so long as the leading edge or rim 22 of the cap 21 bears against the inside surface of the lip, the magazine tube is forced up as the cap is drawn onto the tube end. Specific reference herein to details of the illustrated embodiment is thus not intended to restrict the scope of the claims, which themselves recite those features regarded as essential to the invention.

Claims

I claim:

1. In an autoloading firearm having a barrel and a magazine tube slidably disposed through a barrel ring fixedly depending from the barrel and held in place by a magazine end cap placed over the forward end of the magazine tube, the barrel ring having a channel aligned with ports through the walls of the barrel and magazine tube such that firing gases are directed into the magazine tube to activate loading of the forearm when it is fired, the improvement which comprises:

a forwardly extending lip integral with a lower arcuate portion of said barrel ring; and

a rim on said cap configurated to bear upon the inner surface of said lip as the cap is advanced toward the ring, constituting a means to force the magazine tube and its port up in said ring to seal around the channel to prevent the escape of firing gases at the juncture between the tube and the ring.

2. The improvement according to claim 1 wherein said cap threadably engages the end of the magazine tube to be adjustably drawn thereonto.

3. The improvement according to claim 1 wherein said lip generally tapers in thickness away from said barrel ring.

4. The improvement according to claim 3 wherein said rim of said cap is beveled to approximately match the taper of said lip.

5. The improvement according to claim 1 including stop means to stop said cap after said rim has ridden a substantial distance on said lip.

6. The improvement according to claim 5 wherein said stop means comprises an integral, circumferential flange on said cap and a rabbeted portion is formed on said barrel ring to abut said flange to stop said cap after said rim has ridden a substantial distance on said lip.