Self-propelled pneumatic ram boring tool - has striker piston and control piston and start valve in compressed air feed

摘要

Self-propelled, pneumatic ram boring tool with a striker tip held by a housing and a striker piston which can move in the housing where the forwards and backwards movements of the striker piston are, effected with compressed air fed through a control piston engaging in the striker piston. A start valve with an air-dependent switch threshold is introduced into the compressed air feed of the ram bore tool. This valve can be fitted directly at the compressed air inlet of the housing or in a compressed air line passing to the housing.