Impact action mechanism

Claim 1

An impact action device comprising: a hollow housing; a sleeve having an internally provided space open at one end and a thickened bottom portion, said sleeve having an external lateral surface and being accommodated in an internal space of said housing and operatively coupled to said housing so that the bottom portion of said sleeve defines the end face of said housing; an impact member reciprocably movable through working strokes and return strokes and having an enlarged front portion and a tail portion, mounted in the internal space of said housing so that said enlarged front portion thereof defines with the front part of said housing a buffer chamber for driving said impact member through said return strokes, while said tail portion of said impact member defines with said housing an annular gap and is receivable in the space of said sleeve; a closed combustion chamber defined in said sleeve by additional introduction of the tail portion of said impact member into the internal space of said sleeve; a first passageway formed in the bottom portion of said sleeve and communicating with said combustion chamber, said passageway being open in the end face of said housing for supply of a combustible matter into said combustion chamber to propel said impact member through the working strokes thereof by combustion of said combustible matter; a second passageway formed in the bottom portion of said sleeve and communicating with said combustion chamber, said second passageway being open in the end face of said housing for communication with ambient atmosphere, to provide for exhaust of the products of combustion from said combustion chamber; a plurality of ports provided in said sleeve and communicating with the internal space thereof, said ports being periodically closed off by said tail portion of said impact member during return strokes thereof; a plurality of grooves formed in the external lateral surface of said sleeve and registering with respective ones of said plurality of ports at one end of said grooves, said groves communicating at the respective opposite ends thereof with the respective ones of said first and second passageways, to establish communication of said first and second passageways with said combustion chamber, respectively, to supply said combustible matter thereinto and to exhaust said combustion products therefrom whereby the periodical closing off by said tail portion of said ports separates said combustion chamber from said first and second passageways, during combustion of said combustible matter therein to effect working strokes of said impact member and subsequent exhaust of said combustion products.