PNEUMATIC CARTRIDGE Russian patent published in 2002 - IPC

FIELD: mining industry; applicable in breakage of rocks by high-pressure compressed air, and also in secondary breakage of oversizes. SUBSTANCE: pneumatic cartridge has body with working chamber and exhaust holes; spring-loaded step piston installed for engagement with spherical movable supports and for shutting-off body exhaust holes; stope device for preventing its pushing out of borehole; sleeve installed on body for sliding relative to it. Step piston separates body cavity into working chamber and auxiliary cavity in body tail part. Spherical movable supports are made in form of balls installed in body through radial recesses and advanced toward piston through value of L ≤ D/2, where D is balls diameter. Balls diametrically opposite sides thrust against sleeve internal surface restricted by two recesses. Width of recesses equals or exceeds ball diameter, and depth of recesses equals L. Front chamber formed between body and face is made for accommodation of gaseous chemical substance. Sleeve has calibrated windows for electric conductors of initiator. Secured to sleeve base is buffer having hook for small rope. Body has pipe union with check valve for filling of working chamber with compressed air under preset pressure. EFFECT: higher efficiency due to use of pneumatic cartridge of individual operation and reduced time of transient process of cartridge operation by employing sources of external force. 1 dwg