Collapsible basewad
US4970959A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1989 |
| Grant date | Nov 20, 1990 |
| Priority date | — |
| Expiry date | Aug 15, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF42B5/313
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In combination with a cartridge case having a tubular wall and a head closing one end of the wall, a primer disposed through the head and a propellant charge in the case, a collapsible basewad is disclosed which comprises a unitary body between the charge and the head. The unitary body has an upwardly concave upper portion opening to the propellant charge and a generally cylindrical base portion. The upper portion is deflectable. These portions and the tubular wall define therebetween an annular cavity rearward of the propellant charge. This cavity is collapsed upon ignition of the propellant charge by deflection of the upper portion thereby reducing the recoil felt by the shooter without adding any parasitic weight to the projectile load. The upper portion of the basewad preferaly has an inverted truncated hollow cone shape. An upwardly open annular channel in the upper end surface of the base portion of the basewad enhances the sealing force between the base portion of the basewad and the tubular wall of the cartridge casing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.