| 摘要 |
882,468. Door operating appliances. EMERY, A. A. Sept. 23, 1958 [Sept. 26, 1957], No. 30316/58. Class 65(1). A door, especially a vertically sliding folding garage door, is operated by a hydraulic ram or jack 1 from which extends a pair of cables 14 secured commonly at 13 to the end of the ram piston and separately to the vertical side edges of, as shown, the lower folding panel 4b of the door. The upper panel 4a is pivoted at 22 in the door frame and the lower panel slides in guides 20, bent backwardly at 20a so that the door lies beneath the pivots 22 when shut. The ram is controlled by compressed air, which forces fluid through a pipe 10 and which is afterwards released to atmosphere, and the area between the piston and cylinder in cross-section is the same as that of the pipe 10 so that if the piston rings become worn the door will shut at the same speed as normal. |
