Patent ID: 7828041

Claim:
A manually actuatable roll-up window shade for a motor vehicle comprising: a rotatably supported wind-up shaft having first and second ends; a shade element having a first edge fixed to the wind-up shaft; a pull rod connected to a second end of the shade element remote from the wind-up shaft; two guide rails for guiding the pull rod that extend on opposite sides of the shade element when the shade element is in an extended position; two elongated push elements each of which is guided by a respective one of the guide rails, said elongated push elements each having discrete opposite ends with one of said ends interacting with the pull rod and a second end remote from the pull rod; two drive gears arranged adjacent the first and second ends of the wind-up shaft, said elongated push elements each extending in tangential relation to a respective one of said gears, said push elements and gears having positively interengaging outer peripheries such that movement of said elongated push elements rotates said gears, said drive gears each being coupled to the wind-up shaft via a separate spring tensioning mechanism, said push elements each having a respective storage tube for receiving and holding a section of the push element adjacent the second end when the window shade is in a retracted position; said pull rod being manually movable between a shade retracted position adjacent said wind-up shaft and a shade extended position remote from the wind-up shaft, said manual movement of said pull rod to said extended position being operable for rotating said wind-up shaft, which in turn is operable via the spring tensioning mechanism for rotating the drive gears and moving the push elements to extended positions, said manual movement of said pull rod from said extended position to said retracted position being operable for forcing the push elements toward a retracted position and in turn rotating said drive gears and wind-up shaft in an opposite direction via said spring tensioning mechanism, said manual movement of said pull rod being effective for overcoming frictional resistance of the push elements in the guide rails and storage tubes together with any resistance biasing force of the spring tensioning mechanisms, and said frictional resistant forces of said push elements in said guide rails and storage tubes being greater than the resistance biasing force of the spring tensioning mechanisms such that the pull rod may be stopped and retained by the frictional resistance forces at any location between the extended and retracted positions.