BEAM OR GIRDER FOR BUILDING CONSTRUCTION AND A BUILDING UNIT INCLUDING SAID BEAM OR GIRDER, AND A METHOD OF MANUFACTURING THE BEAM OR GIRDER

摘要

For remote indication of the position of the movable member (7) of a double-acting, fluid-pressurized hydraulic setting motor (6) communicating with two control conduits (A2, B2) for the supply and removal of pressure fluid to actuate the movable element (7) for movement in an opening direction or in a closing direction, use is made of a volumeter (3) having a capacity corresponding to the stroke volume of the setting motor (6). The two control conduits (A2, B2) may be connected through a multi-way valve (2) with a pressure line (P) and a tank line (T) or, in a neutral state both of them may be connected with the tank line (T). The volumeter (3) is coupled to the multi-way valve (2) in such a manner that in both operating positions it is connected into the control line connected with the tank line (T), whereas it is barred in the neutral condition. The two control conduits are connected with the setting motor over pilot controlled non-return valve arrangements (4) each of which in the neutral state prevents pressure fluid from passing from the setting motor to the control conduits, whereas in the operating position return of pressure fluid to tank is being opened only after a sufficient working pressure has been established in the pressurized control conduit.