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Publication numberUS3869961 A
Publication typeGrant
Publication dateMar 11, 1975
Filing dateMar 19, 1973
Priority dateMar 19, 1973
Publication numberUS 3869961 A, US 3869961A, US-A-3869961, US3869961 A, US3869961A
InventorsKawamura Takeji
Original AssigneeKawamura Takeji
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Action spring assembly for forwardly urging the action bar of shotguns
US 3869961 A
Abstract
A shotgun includes an action spring assembly forwardly urging the action bar. The action spring assembly has a pair of coil springs arranged in a row and a shock absorbing member interposed between the coil springs. The shock absorbing member is constructed by two rings so assembled that they may buffer the force applied to one spring and transmit the buffered force to the other spring when the action bar is returned to its orginal position.
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Description  (OCR text may contain errors)

Elnite Sttes Kawamura ACTION SPRING ASSEMBLY FOR FORWARDLY URGING THE ACTION BAR 0F SHOTGUNS llakeji Kawamura, 1388-1 Akahane, lshinazaka-cho, lHitachi-shi, Ibaragi-ken, Japan Filed: Mar. 19, 1973 Appl No: 342,599

inventor:

U.S. Cl. 89/191 A, 89/198 Int. Cl. F41d 5/04 Field of Search 89/191 R, 191 A, 192, 193,

References Cited UNITED STATES PATENTS Clair 89/192 [451 Mar. 11, 1M5

1,066,206 7/1913 Jolidon 89/190 2,451,624 10/1948 Loomis et al............ 89/191 3,306,168 2/1967 Blumrick 89/190 Primary ExaminerStephen C. Bentley Attorney, Agent, or Firm-Thompson, Birch, Gauthier & Samuels [57] ABSTRACT A shotgun includes an action spring assembly forwardly urging the action bar. The action spring assembly has a pair of coil springs arranged in a row and a shock absorbing member interposed between the coil springs. The shock absorbing member is constructed by two rings so assembled that they may buffer the force applied to one spring and transmit the buffered force to the other spring when the action bar is returned to its orginal position.

3 Claims, 4 Drawing Figures ACTION SPRING ASSEMBLY FOR FORWARDLY URGING THE ACTION BAR OF SHOTGUNS BACKGROUND OF THE INVENTION This invention relates to a shotgun and more particularly to an improvement of an action spring assembly of an action bar used in the shotgun.

A conventional shotgun or fire arm is provided with an action bar which is rearwards moved through a piston with propellant gases generated upon firing of the shotgun so as to bring the shotgun to a waiting condition. The action bar is then returned to its original position by a coil spring when the pressure of propellant gases is decreased. The returning of the action bar by the coil spring heretofore has been accompanied with a great shock force and sound.

SUMMARY OF THE INVENTION Accordingly. an object of the present invention is to provide an action spring assembly which may return the action bar of the shotgun without a great shock force and sound.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a shotgun including an action spring assembly according to an embodiment of the present invention;

FIG. 2 is a sectional view of the part of the shotgun shown in FIG. l;

FIG. 3 is an enlarged sectional view of the buffer member of the spring assembly; and

FIG. 4 is a perspective expanded view of a pair of rings of the buffer member.

DETAILED DESCRIPTION OF THE INVENTION There will now be described one embodiment of the present invention with reference to the accompanying drawings.

As shown in FIG. 1, a shotgun body l is ofa conventional configuration having a barrel 2, receiver 3, and butt 4. From the receiver 3 there is extended a magazine tube 5 on which an action bar 6 is provided as shown in FIG. 2. The action bar 6 includes a short cylindrical section or forward part 7a slidably mounted around the magazine tube 5 and a pair of parallel bars or rearward parts 7b with one end fixed to the rear upper part of the cylinder 7a and the other end connected to a sliding member as described later. The front end of the cylinder 7a is securely connected to the rear end of a piston 8 slidably received in a cylinder 10, so that the action bar may be moved with the piston. The piston 8 may be moved, rearwards or in a direction of an arrow A, against an action spring assembly 11 with propellant gases which have been generated in the barrel 2 at firing of the shotgun and then introduced into the cylinder 10 through an inclined passage 9 formed in the wall of the barrel.

The action spring assembly 11 is mounted around the periphery of the magazine tube, which comprises apair of coil springs 12 and 13 having substantially the same length and diameter, and a buffer member 14 interposed between the coil springs and contacted with them. The forward end of one coil spring 12 abuts on the rear end of the short cylindrical section 7a and the rear end of the other coil spring 13 is fixed to the flange 5a, so that the action bar 6 is usually urged in a forward direction of an arrow B by the spring assembly.

The buffer member 14 is constructed of a pair of metal rings 15 and 16 with the same diameter. One ring 15 is formed with a transverse cut 15a in the part of its periphery thereby to elastically expand to have its diameter broadened. At one end portion of the ring 15 there is formed an inclined inner surface 15b. The other ring 16 has at the end portion an outer surface 16b inclined at the same angle as the inclined surface of said one ring 15 so that both inclined surfaces 15b and 16b may be slidably contacted with each other.

The rear end of the action bar is connected to the sliding member 17 which is received in the under part ofa bolt 19 slidably mounted in a charging room 18 expanded from the base of the barrel 2 to the receiver 3. As a conventional manner, the sliding member 17 may be slid within a certain range in the bolt 19. The bolt 19 may cooperate with the action bar 6 through the sliding member 17 and slid to a direction of an arrow C with propellant gases at firing of the shotgun.

With the spring assembly constructed as described above, when the action bar which has been slid in a direction ofan arrow A is moved in a direction of an arrow B to return its original position, the buffer member of the spring assembly may buffer the force applied to one coil spring and to transmit the buffered force to the other coil spring, so that the shock force and sound are effectively decreased.

What is claimed is:

1. In a spring assembly returning an action bar to its original position which has been moved in one direction by a piston, the improvement comprising a pair of coil springs arranged in a row and a shock absorbing member interposed between said coil springs to buffer the force applied to one spring and to transmit the buffered force to the other spring, said shock absorbing member having first and second rings arranged coaxially with the coil springs and contacted with each other, the first ring being able to be resiliently expanded in a radial direction when being pressed by the second ring.

2. The spring assembly according to claim 1 wherein the first ring has a traverse cut.

3. The spring assembly according to claim 2 wherein the inner surface of the first ring has a portion inclined at an angle on one side and the outer surface of the second ring has a portion inclined at the same angle as the inclined portion of the first ring to contact with the same.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US483539 *Mar 20, 1889Oct 4, 1892 claie
US1066206 *Jul 6, 1909Jul 1, 1913Charles J JolidonMagazine-firearm.
US2451624 *Aug 27, 1947Oct 19, 1948Remington Arms Co IncInertia rate of fire retarders
US3306168 *Aug 16, 1965Feb 28, 1967Blumrick Howard JGas operated semi-automatic pistol
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4244273 *Dec 4, 1978Jan 13, 1981Langendorfer Plastics CorporationRifle modification
US4389920 *Feb 20, 1981Jun 28, 1983Dufour Sr Joseph HSemiautomatic firearm
US5076139 *Aug 29, 1990Dec 31, 1991Hiett Charles ABuffer for firearms
US7231864Jul 23, 2004Jun 19, 2007Andres RattiReciprocating barrel firearm apparatus
US7461581 *Jul 24, 2006Dec 9, 2008Lwrcinternational, LlcSelf-cleaning gas operating system for a firearm
US8176837Oct 11, 2010May 15, 2012Jason Stewart JacksonFirearm operating rod
US8245625 *Jun 26, 2009Aug 21, 2012Winge Michael LGas pressure mechanism in gas-operated firearm
US8640598Jul 16, 2011Feb 4, 2014Jason Stewart JacksonSleeve piston for actuating a firearm bolt carrier
US20130036900 *Aug 8, 2011Feb 14, 2013Stephen Mark MuellerRecoil Apparatus for Firearm
Classifications
U.S. Classification89/191.2, 89/198
International ClassificationF41A5/18, F41A3/00, F41A5/00, F41A3/86
Cooperative ClassificationF41A5/18, F41A3/86
European ClassificationF41A3/86, F41A5/18