A position sensor for the piston of a drill, and control device comprising application of this sensor

• Main Author: PIERRE FOUR, JEAN-JACQUES SCHWARZ ET JEAN-CLAUDE COMMERCON
• Format: Patent
• Language: English; French
• Published: 22.01.1988
• Edition: 4
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; BLASTING; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR; FLUID-PRESSURE ACTUATORS; FLUID-PRESSURE ACTUATORS, e.g. SERVO-MOTORS; HAND TOOLS; HEATING; HYDRAULICS OR PNEUMATICS IN GENERAL; LIGHTING; MANIPULATORS; MEASURING; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; MECHANICAL ENGINEERING; PERCUSSIVE TOOLS; PERFORMING OPERATIONS; PHYSICS; PORTABLE POWER-DRIVEN TOOLS; SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; TARIFF METERING APPARATUS; TESTING; TRANSPORTING; WEAPONS

A metal ring 14, stationary with respect to the body of the drill and electrically isolated, constitutes an armature for a cylindrical capacitor, whose other armature consists of the rear part of the piston 4 itself. The capacitance of the capacitor varies proportionally to the length L of the piston surrounded by the ring 14, which allows the position and the speed of the piston 4 to be determined at any instant, in particular in order to determine the energy transfer efficiency from the drill to the rock. UNE BAGUE METALLIQUE 14, FIXE PAR RAPPORT AU CORPS DE LA PERFORATRICE ET ISOLEE ELECTRIQUEMENT, CONSTITUE UNE ARMATURE D'UN CONDENSATEUR CYLINDRIQUE, DONT L'AUTRE ARMATURE EST CONSTITUEE PAR LA PARTIE ARRIERE DU PISTON 4 LUI-MEME. LA CAPACITE DU CONDENSATEUR VARIE PROPORTIONNELLEMENT A LA LONGUEUR L DU PISTON ENTOUREE PAR LA BAGUE 14, CE QUI PERMET DE DETERMINER LA POSITION ET LA VITESSE DU PISTON 4 A TOUT INSTANT, NOTAMMENT POUR DETERMINER LE RENDEMENT DU TRANSFERT D'ENERGIE DE LA PERFORATRICE A LA ROCHE.