| 摘要 |
1. Means for opening a door (1), more especially a fire door, having an operating cylinder which can be actuated pneumatically or hydraulically and of which the cylinder housing (10) is fixed on the door frame, the wall or the like and of which the piston rod (21) consisting of a tube is fixed on the door (1) and which is coupled with a pressure medium source (9), so that when pressure medium is supplied, pressure medium forcing the piston rod (21) out of the cylinder housing (10) passes into the space (18) between the piston (20) and the bottom wall of the cylinder housing (10), that end region of the cylinder housing (10) which faces away from the bottom wall of the cylinder housing (10) being sealed off with respect to the piston rod (21), wherein the tubular piston rod (21), in its end region adjacent the piston (20), comprises at least one inlet opening (23, 24) for the admission of pressure medium and, in its end region remote from the piston (20), an outlet opening (29) for the discharge of pressure medium and connected to one side of a valve (27) to be opened by means of a handle or release lever (2) of the door (1), wherein a pipe line (26) connected to the piston rod (21) is provided an open end of which line is guided through the piston (20) while its other end is led out of that end region of the piston rod (21) which is remote from the piston (20), sealed off from the internal space thereof, and is connected to the other ead of the valve (27), so that, with opening of the valve (27), compressed air flows form the outlet opening (25) through the pipe line (26) into the space (18) between piston (20) and bottom wall of the cylinder housing (10) and, with closing of the valve (22), compressed air is vented from the space (18) through the pipe line (26), and wherein that end region of the cylinder housing (10) which is remote from the bottom wall of the cylinder housing (10) comprises an inlet (12) for feeding pressure medium to the annular space (19) between cylinder housing (10) and piston rod (21). |
