| 摘要 |
<p>1501496 Pinless hinges F J McCABE 2 June 1975 [5 June 1974] 23805/75 Addition to 1461458 Heading E2F [Also in Division F4] A backdraft damper of the kind illustrated in the parent specification (which damper comprises a blade extending between and pivoted to opposite sides of a frame, the blade having integrally formed along its upper edge a hook shaped hinge portion which at each end interfits a hook shaped hinge element integrally formed in the frame) further comprises bearing means 38 (or 48, Fig. 6, not shown) disposed between (a) the hinge portion 18 of the blade and (b) each hinge element 36 of the frame. As shown, the hinge portion 18 includes a part folded back on itself. The bearings 38 are force-fitted on the ends of the hinge portion 18. The bearings may be of stainless'steel or low friction plastics. The pivoting arrangement is such that the arc of displacement of the blade is limited to an acute angle.</p> |
