PNEUMATIC PERCUSSION APPARATUS AND METHOD FOR CONTROLLING AIR DISTRIBUTION IN SUCH APPARATUS Russian patent published in 2005 - IPC

FIELD: pneumatic percussion apparatuses designed, mainly for trench-free replacement of old pipelines and laying new ones, methods for controlling air distribution in such apparatuses.

SUBSTANCE: in pneumatic percussion apparatus surface areas of annular cross sections of striker at side of inner and outer chambers are almost the same. Spacing between outer end of striker and axis of openings of striker and striker stroke are selected according to condition that they are almost equal to half values of distances between axis of openings of striker and inner end of striker and between outer end of striker and its inner end respectively. In such apparatus air flows are distributed between working chambers and exhaust ducts by means of mechanical members. In order to provide operation of apparatus in mode of back exhaust, working chamber of back stroke of striker is communicated with atmosphere through outer chamber and inner chamber is communicated with pneumatic main line. In order to provide operation of apparatus in mode of front exhaust, working chamber of reverses stroke of striker is communicated with atmosphere and outer chamber is communicated with pneumatic main line.

EFFECT: enlarged range of using, enhanced operational reliability, simplified operation of apparatus, air distribution process providing exhaust of waste air in backward and forward directions in pipeline depending upon technical needs.

10 cl, 7 dwg