Abstract: As one non-limiting example, a foldable mast assembly for a sailing vessel is provided. The foldable mast assembly includes a lower mast section; an intermediate mast section having a lower end foldably coupled to an upper end of the lower mast section; an upper mast section having a lower end foldably coupled to an upper end of the intermediate mast section; and a boom coupled to the lower mast section. A locking device internal the mast assembly is also provided to inhibit folding of the mast assembly.

Abstract: As one non-limiting example, a foldable mast assembly for a sailing vessel is provided. The foldable mast assembly includes a lower mast section; an intermediate mast section having a lower end foldably coupled to an upper end of the lower mast section; an upper mast section having a lower end foldably coupled to an upper end of the intermediate mast section; and a boom coupled to the lower mast section. A locking device internal the mast assembly is also provided to inhibit folding of the mast assembly.

Abstract: Sliders having air bearing surfaces are disclosed for use with magnetic recording and reading heads in a magnetic disk drive assembly to reduce the pressure gradients resulting from the flow of air between the slider and the spinning disk. To relieve such pressure gradient, the bottom surface of the air bearing surface at or near the trailing edge includes one or more recesses, which may be one or more steps, inclined ramps, curves or other configurations. Other surfaces of the slider may also include recesses to relieve these pressures. The sliders having air bearing surfaces may be attached to, or integral with, a magnetic recording or reading head in a magnetic disk drive assembly. A method of reducing the formation of pressure gradients is also disclosed whereby air flow between the disk and the head creates a pressure greater than atmospheric, at least a part of which is released through a recess on the air bearing surface of the slider.