| 摘要 |
The spring unit (16) for a door closer comprises a housing (17) containing hydraulic fluid, a piston (18) movable in housing and fixed to a piston rod (19) extending out through a sealed opening in the housing first end (17a). A spring component (27) is arranged between the piston and the first end and with spring effect presses the piston towards an intermediate base (29) in the other end of the cylinder. A channel (33) is formed in the intermediate base and a closure component (34) is made of a material with such a melting point that when the hydraulic fluid is heated in the event of a fire it melts, providing passage for the fluid through the channel. |
