| 摘要 |
536,107. Door-operating appliances. GROOM, G. W. Nov. 24, 1939, No. 30707. [Class 65 (i)] A door closer comprises a cam n on the door pivot a engaging rollers e on a slide d which has pin and slot connection m, f with a fixed cross plate b, and engages the piston of a fluid check k. During the opening of the door, a crosshead g operated by a crank on the pivot a compresses springs j, and during the closing movement, the check piston resists the springs. |
