An improved coupling drive unit

A coupling unit for transmitting rotary movement from a drive member outside a containment to a driven member within the containment. The members are rotatably journalled in a housing with a link bar supported by a gimbal ring extending between diametrically opposed positions on the members. A flexible diaphragm which is clamped between first and second parts of the link bar extends across the housing to isolate the driving member from the driven member. (author)