Patent ID: 8763482

Claim:
A push-pull chain actuator comprising: a housing with a chain exit/entry opening, a push-pull roller chain with an open back, a sprocket arranged to engage rollers of the push-pull roller chain, whilst a portion of the push-pull roller chain is guided around the sprocket, said sprocket causing a polygon effect during operation, a chain guide comprising: a first arc shaped chain guide part for guiding said portion of said push-pull roller chain around said sprocket by the rollers of the push-pull roller chain being guided by the first arc shaped chain guide part, a second chain guide part for guiding said push-pull roller chain in a predetermined exit/entry direction between the sprocket and a chain exit opening by the rollers of the push-pull roller chain being guided by the second chain guide part, wherein said second chain guide part is shaped and dimensioned to neutralize or at least reduce the polygon effect of the sprocket on the push-pull roller chain by including a deviation from a straight line that causes the rollers to follow a meandering path between the chain exit opening and the sprocket, wherein the second chain guide part comprises a path for said rollers formed by a series of interconnected arc shaped sections, wherein geometrical centres of said arc shaped sections are on a same side of the push-pull roller chain as geometrical centres of the first chain guide part, and wherein the geometrical centres of said arc shaped sections are substantially arranged on a line (Y) extending parallel to the predetermined chain exit/entry direction.