REVERSIBLE PNEUMATIC PUNCH (VERSIONS) Russian patent published in 2005 - IPC

FIELD: trenchless underground pipe laying.

SUBSTANCE: invention relates to trenchless laying of underground pipelines of considerable length and preset trajectory. Proposed punch includes body accommodating reciprocating striker with bore in rear part, spool getting into bore by larger diameter step with sliding. Spool consists of branch pipe secured in rear part of body and sleeve connected with branch pipe for sliding and spring-loaded relative to rear part of body with at least one radial pin getting into ring zigzag slot made on part fixed on body. Sleeve of spool encloses front part of its branch pipe, being spool larger diameter step, and said ring zigzag slot is made on outer surface of branch pipe. According to first design version, at least one radial hole is made on front parts of branch pipe and spool sleeve. According to second design version, flats are made additionally on outer surface of branch pipe displaced towards rear part of branch pipe. According to third design version each second cavity on rear side of ring zigzag slot is extended to side of rear part of branch pipe.

EFFECT: improved reliability and increased service life owing to making of pneumatic punch of closed type with reversing of delivery of compressed air simply by switching off and on.

7 cl, 19 dwg