| 摘要 |
A door closer comprising a body (10), first and second passages (11, 12) in the body, a pinion (17) extending through the first passage and out of the body, a rack (18) engaged by the pinion, a spacer (19) attached to the rack, and a piston, having a head (22) slidable in the second passage, and a stem (21) which is secured to the spacer by a bolt (20). At the junction between the first and second passages is a rubber rolling diaphragm seal (25) which has an outer bead part (24) secured at a shoulder (13) between the passages (11, 12) and an inner flat end wall part sandwiched between the spacer (19) and the piston stem (21). This seal (25) isolates the pinion (17) from the hydraulic fluid of the closer, which is contained in a sealed enclosure defined between the seal and a closed end of the second passage (12). In a chamber (40) defined in the second passage (12), is a rubber bag-like container (42) having compressed air therein. The container acts as energy storage means to be compressed by hydraulic fluid on movement of the piston in one direction during door opening, and to expand to force the fluid to move the piston in the opposite direction for door closing. <IMAGE> |
