DISPOSITIF DE PERCUSSION PNEUMATIQUE REVERSIBLE

L'INVENTION CONCERNE LES MACHINES A PERCUSSION.LE DISPOSITIF FAISANT L'OBJET DE L'INVENTION EST CARACTERISE EN CE QUE LE PREMIER GRADIN 6 ET LE DEUXIEME GRADIN 7 DE LA TUBULURE CYLINDRIQUE 5 SONT DISPOSES COAXIALEMENT, LA BAGUE 14 A RESSORT ETANT MONTEE SUR LEDIT DEUXIEME GRADIN 7 DE LA TUBULURE 5, A L'INTERIEUR DE SON PREMIER GRADIN 6, ET LE DIAMETRE EXTERIEUR DE LADITE BAGUE 14 ETANT SENSIBLEMENT PLUS PETIT QUE LE DIAMETRE INTERIEUR DUDIT PREMIER GRADIN 6 DE MANIERE A FORMER ENTRE EUX UN CANAL ANNULAIRE 15.L'INVENTION PEUT ETRE UTILISEE NOTAMMENT DANS LE GENIE CIVIL ET LA CONSTRUCTION DES ROUTES. An air-operated reversible percussive action machine comprises a housing in which there is disposed for axial reciprocations a hammer, defining therewith a front working chamber and having a through radial passage. In the axial interior of the hammer on the side of its tail end there is provided a cylindrical stepped tube including coaxially arranged first and second steps of large and small diameters, respectively, these steps having through radial passages. The first step of the tube defines with the hammer a rear working chamber, and with the second step defines an annular cavity in which a spring sleeve capable of axial displacements is disposed. The outer diameter of the sleeve is substantially less than the inner diameter of the first step of the tube to form an annular passage there between. The machine is further provided with a means for pressure-sealing the annular cavity and a means for controlling the displacements of the sleeve.