MOTOR DRIVEN TYPE CLOSURE OPERATION APPARATUS

摘要

A closure operator such as a garage door operator utilizes an apertured flexible tape. The tape is enclosed in a guide and a drive sprocket has teeth engaging the apertures to apply both tension and compression forces to open and close a door. The apertures are enlarged in width and length and the tape has fewer apertures per-unit-length compared to the prior art tape. This decreases the stress per-unit-area in the tape at each tooth and increases the shear strength of the webs between successive apertures to be more nearly equal to the tensile strength of the tension band areas of the tape.