| 摘要 |
1537005 Door hold-open devices EATON GmbH 18 March 1977 [19 March 1976] 11537/77 Heading E2M A door hold-open device comprises a housing 9 and a mounting bracket 5 which are connected to effect relative pivotal movement when the door is moved; a piston 13 being displaced in the housing when such movement occurs and two passages for pressure medium (one with a one-way valve and the other with an over pressure valve) interconnecting opposite sides of the piston. As shown bracket 5 is fixed to a door surround and carries a mounting part 6 about which a bearing 8 secured to the housing can pivot when the door 4 is opened. The door is provided with a spring closer 2 connected to the housing via a linkage 3, 3'. The piston 13 is urged upwardly by spring 15 and carries inclined surfaces 13' which, when the door is open about 90‹, enter recesses 8<SP>v</SP> in bearing 8. A one-way valve 16 allows fluid flow past the piston as it moves up during opening and an over pressure valve (Figs. 5, 6 not shown) prevents return flow to hold the door unless the pressure exceeds a pre-set level or an electromagnet release is operated which acts on the valve. |
