Abstract: A sailboard is disclosed of the type having a mast pivotally connected to a board, a boom connected at one end to the mast and a sail tensioned by out haul and down haul lines. A down haul tie down mechanism is provided for receiving and securing the down haul line at a location adjacent to the sailboard pivot. A cup with a special release mechanism is provided for releasably connecting the mast to the pivot. Release mechanisms for releasably interconnecting other sailboard components, such as boom sections and boom extensions, are also disclosed.

Abstract: A sailboard is disclosed of the type having a mast pivotally connected to a board, a boom connected at one end to the mast and a sail tensioned by out haul and down haul lines. A down haul tie down mechanism is provided for receiving and securing the down haul line at a location adjacent to the sailboard pivot. A cup with a special release mechanism is provided for releasably connecting the mast to the pivot. Release mechanisms for releasably interconnecting other sailboard components, such as boom sections and boom extensions, are also disclosed.

Abstract: A road planer machine having a housing containing a rotating planer drum and having access doors in the housing for maintenance and inspection of the cutting equipment which includes detectors for determining when the access doors are not in their normally closed positions and for disabling the propulsion system of the planer machine as well as the drum rotating system so that the machine can neither move nor the drum rotate if any of the access closure doors are not in their normally closed position.