| 摘要 |
A blind includes panels or slats which are pivotally supported on cross levers which in turn are supported at their respective outer ends between sets of toggle levers with two pivotally connected toggle levers being located between each adjacent pair of cross levers on each end thereof. A pulling member comprises an endless band or chain which is directed over an upper driving wheel carried on the pullup shaft and may also advantageously be directed around the bottom guide wheel mounted in the blind housing. The pulling member is connected by a driver with the end journal of the lowermost blind panel so that when it is moved, it may raise or lower the complete set of blind panels. The toggle members which connect one end of the cross levers is connected through a chain which extends over the upper driving wheel and connects to the toggle levers on the opposite ends of the cross levers. The toggle levers form toggle joints which can be bent out in the same direction with parallel guidance of the cross levers and the pullup shaft is advantageously rotated by a driving mechanism to simultaneously shift the front and rear set of toggle levers for the purpose of orienting the cross levers and the associated blind panels between substantially horizontal open positions or substantially vertical close positions.
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