摘要 |
The present invention concerns a chain operator for a window which comprises a chain formed of a plurality of interconnected chain links and a casing having a spaced first and second chain exit openings. A chain guide track is disposed in the casing and extends between the first and second chain exit openings and is positioned to guide the chain between the chain exit openings. One end of the chain is affixed to a window and a drive sprocket is rotatably mounted in the casing. The drive sprocket has a plurality of sprocket teeth which lie along the planar surface of the drive sprocket and are engagable with the chain to drive the chain between the chain exit opening when the drive sprocket is rotated. A guide arrangement is positioned in the casing adjacent one of the chain exit openings and guides the chain links near the chain exit opening and maintains the chain links substantially in the plane of the planar surface of the drive sprocket, as the chain links move through the casing into engagement with the sprocket teeth. The guide arrangement thereby avoids jamming of sprocket teeth in the chain links and minimizes undesirable noise producing engagement of chain with the casing. Another feature of the present invention includes the use of stablizing rings disposed in position to engage and maintain the drive sprocket from substantial wobbling during rotation and thereby further preventing misalignment between the sprocket teeth and the chain links.
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