# US 4,392,412 A · Gaseous blast reducer

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- Number: US 4,392,412 A
- Document ID: US4392412A
- Status: Granted
- Kind: A
- Application number: 06/202,220
- Filed: 1980-10-30
- Granted: 1983-07-12
- Earliest claimed: 1980-10-30
- Assignees: The United States of America as represented by the Secretary of the Army
- Inventors: Edward M. Schmidt; George D. Kahl
- Web page: https://patentgrep.com/patent/US4392412A

## CPC

- F42D 5/045: Detonation-wave absorbing or damping means
- F41A 21/30: Silencers
- F41F 3/04: for rockets
- F42D: BLASTING (fuses, e.g. fuse cords, C06C5/00; {for obtaining fluid from wells E21B43/00; for mining or quarrying E21C37/00; for making tunnels or galleries E21D9/006}; cartridges F42B3/00)
- F41A: FUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE
- F41F: APPARATUS FOR LAUNCHING PROJECTILES OR MISSILES FROM BARRELS, e.g. CANNONS (smallarms F41C); LAUNCHERS FOR ROCKETS OR TORPEDOES; HARPOON GUNS (functional features or details common to both smallarms and ordnance, mountings therefor F41A; projecting missiles without use of explosive or combustible propellant charge F41B)

## Abstract

A gaseous blast reducer employs a membrane which is effective to contain a ass of gas having properties different from air, in the vicinity of the source of the blast. The blast is forced to propagate through the mass of gas before propagating in the air. An acoustic mismatch caused by the difference in properties between the gas and air reduces or attenuates the blast.

## Claims

### Claim 1

Apparatus for reducing blast from an explosive source which includes:
a gun barrel having a muzzle;
means for supplying a gas, which includes a pressurized container containing said gas;
means for containing said gas in the vicinity of said source whereby the blast is forced to propagate through said gas before reaching ambient air which includes:
an inflatable membrane; and
means for securing said inflatable membrane over said muzzle; and
means for releasing said gas into said means for containing.

### Claim 2 (depends on 1)

Apparatus according to claim 1 wherein said inflatable membrane is inflatable by said gas to a generally spherical shape.

### Claim 3 (depends on 1)

Apparatus as recited in claim 1 wherein said gas is helium.

### Claim 4

Apparatus for reducing blast from an explosive source which includes:
a rocket launcher having an outlet;
means for supplying a gas which includes a pressurized container containing said gas;
means for containing said gas in the vicinity of said source whereby the blast is forced to propogate through said gas before reaching ambient air which includes:
an inflatable membrane; and
means for securing said inflatable membrane over said outlet; and
means for releasing said gas into said means for containing said gas.

### Claim 5 (depends on 4)

Apparatus according to claim 4 wherein said rocket launcher includes means for deploying a portion thereof, and said means for supplying a gas includes automatic means for supplying said gas in response to actuation of said means for deploying.