Wishbone-boom for windsurfing boards

Реферат: Abstract: An improved wishbone-boom for windsurfing boards has two outwardly bent booms which serve as manipulating members to control the sail. Each boom has a forward and rearward boom section, these boom sections being telescopically movable relative to each other. Each boom further has a form-locked coupling device that allows a stepwise locking of an adjusted position of the two boom sections relative to each other. Each rearward boom section has recesses distributed along the length thereof, and the coupling device has locking bodies mounted on a curved spring element that biases the locking bodies out of engagement with the recesses. The locking bodies are insertable into the recesses for engagement therewith. The improvement consists of a manually operable control member located on each of the booms and operable upon rotation to insert the locking bodies into the recesses. Each control member is a rotatable sleeve mounted on a boom and encasing the spring element and the locking bodies. The locking bodies are movably held by the spring element within through-bores located in each forward boom section and the sleeve is provided with cam surf aces located at its inner side. The cam surfaces upon rotation of the sleeve urge the locking bodies through the through-bores and into the recesses of the rearward boom section.