VERIN DE TRAVAIL, EN PARTICULIER POUR UN DISPOSITIF DE COMMANDE SIMULTANEE OU TEMPORISEE

• Main Author: WALTER WEIRICH, HARRY ROSENBERG, KUNIBERT BECKER ET MICHAEL DETTMERS
• Format: Patent
• Language: French
• Published: 06.08.1982
• Subjects: EARTH DRILLING; FIXED CONSTRUCTIONS; GALLERIES; LARGE UNDERGROUND CHAMBERS; MINING; SHAFTS; TUNNELS

VERIN DE TRAVAIL UTILISABLE EN PARTICULIER POUR LA COMMANDE SIMULTANEE OU TEMPORISEE DE VERINS DE TRAVAIL TELS QUE DES VERINS D'AVANCE POUR ALLONGES DE CHAPEAU D'UN SOUTENEMENT MARCHANT ET DES VERINS DE RIPAGE POUR LE RIPAGE D'UN CONVOYEUR DU TYPE DANS LEQUEL DES AIMANTS PERMANENTS SONT DISPOSES SUR LA TIGE DE PISTON DU VERIN DE TRAVAIL ET COOPERENT AVEC UN ORGANE DE DETECTION. LES AIMANTS PERMANENTS 60, 63 SONT LOGES DANS DES CAPSULES METALLIQUES NOYEES OU ENCASTREES DANS DES EVIDEMENTS DE LA TIGE DE PISTON 23, 62 ET IMMOBILISES DANS CES EVIDEMENTS. A longwall mineral mining installation has a conveyor and a plurality of roof support units positioned side-by-side on the goaf side of the conveyor. Each roof support unit has a roof shield having an advanceable shield extension. Each unit has a first hydraulic ram for extending its shield extension, and a second hydraulic ram for advancing the conveyor. The extension of each first ram is controlled in dependence upon the retraction of one of the second rams (either the second ram of the same unit or that of an adjacent unit). This control is effected by controlling the supply of pressurized hydraulic fluid to the first rams. In one embodiment this is carried out by a control valve which has a spring-loaded plunger which engages with a series of equispaced cams on the movable cylinder of the associated second ram. In another embodiment, the piston rods of the rams are provided with series of equispaced magnets. The cylinders of the rams are provided with sensors, which sense the magnets and generate control signals. A control box is provided to direct the control signals to control valves associated with the rams, so that the first rams are extended by the same distance as that through which the second rams are retracted.