The device is a modular design with a sliding sleeve member that replaces older grouting injection devices with exit port opening actuated by fluidic pressures...http://www.google.es/patents/US5819850?utm_source=gb-gplus-sharePatente US5819850 - Geotechnical grouting device and method B???squeda avanzada de patentes N???mero de publicaci???nUS5819850 ATipo de publicaci???nConcesi???n N???mero de s