Improvements relating to means for raising and lowering fireproof doors, shutters, and the like

摘要

216,361. Haskins & Bros., Ltd., S., and Haskins, J. June 21, 1923. Hand driving-mechanism. - In raising and lowering means for fire-proof doors and shutters, each operating-handle is mounted freely upon its shaft and is so connected thereto that w h e n limited angular movement in either direction is imparted to any one handle it engages with its shaft while the other handles are unaffected and hang free and so constitute no danger to persons in the vicinity. The shank B is provided with a hub A in which is housed a bush M arranged to surround the shaft freely and constructed with an eccentric enlargement 0 accommodating a roller P adapted to engage frictionally with the shaft when limited angular movement is imparted to the. shank. By this means engagement of the handle and the shaft may be effected progressively whereby the handle serves as a brake to check the rate of descent of the door. The hand-piece G is hinged to the lower end of the shank B and in order that the piece G may be positioned at right angles to the shank means for the releasable engagement of these parts are provided.