| 摘要 |
<p>1336499 Door closer with holding device; universal joint RIXSON FIREMARK INC 24 Sept 1971 44665/71 Headings E2F and E2M In a door closer having a closer-spring and a dashpot damping device operatively coupled to a closer arm 6, a latch 50 which can normally be overridden by the spring, is electromagnetically operable to hold the door in an open position. The spring is coupled by a chain 29 to a rotatable cylinder 33 surrounding a fixed vane 34 and containing a visco-elastic plastics. The cylinder 33 is connected to the arm 6 and carries a cam 37b engageable by the latch 50. The latch is pivotally mounted at 48, pivotally carries a magnetic plate 53 and is spring 55 loaded against an electromagnet 45. The force of the spring 55 alone is not sufficient to keep the latch engaged with cam 37b and hence the door closes but, when the electromagnet is switched on, the door is latched open. The latch 50 may be overrode by applying a manual force to the door or by a smoke or flame detector. The volume between the cylinder 33 and vane 34 may be varied by a screw to thereby vary the damping. The cam 37 may be a roller. The free end of the arm 6 engages a channel member on the door. A pivot arrangement for the plate 53 (Fig. 8) comprises a member 60 having a part spherical surface engaging a like surface in the latch 50, and a rubber O-ring 62.</p> |
