ince the introduction of V-belt drive systems in the 1930' s, Wood' s has been a leading innovator in belted drives. In 1945, Wood' s introduced the quick detachable ( " QD" ) Bushing system. In the early 1950' s the company introduced variable speed pulleys and synchronous timing belt drive systems. In 1957, Wood' s developed and patented its Sure-Flex® couplings and captured a significant segment of the elastomeric coupling market.