Double acting anti-return drive - has double ended spring within cage to act as locking device

摘要

The cylindrical drive bar (1) rotates over a short spindle (8) and has a semi-cylindrical internal end (1c). A similar driven bar rotates on the other end of the spindle, the two semi-cylindrical parts facing each other over the spindle, leaving a narrow gap (9, 11) between them. Round these two parts, is wound a coil spring (12), with an end (12a, 12b) bent round the drive semi-cylinder into each gap. Around the spring is a cylindrical housing (3). For drive conditions the drive end contracts the spring away from the housing and everything rotates, but if the driven end tries to over rotate, or rotate when the drive stops, the spring is expanded and locks on the inside of the housing.