Abstract: A telescoping mast has a plurality of elongate tubular sections which are telescopically attached to each other and an axial drive screw centrally located in the mast for extending and retracting the elongate tubular section. A gear assembly is connected to the drive screw for rotating the drive screw. A nut carrier assembly is secured to tubular sections. Each nut carrier assembly has a threaded nut housed within a nut carrier. The threaded nut engages corresponding threads on the drive screw. A locking mechanism is provided for locking the gear assembly which has a first section surrounding a second section secured to the gear assembly. The second section has an elongated member extending from a surface of the second section. The first section has at least one slot for engaging the elongated member, thereby preventing rotation of the gear assembly.

Abstract: A valve ball physically configured to minimize rotational forces imparted to the ball by fluid pressure acting thereon in flow throttling positions of the ball. In part, the physical configurations that produce the desired effect include a hollowed out ball interior and recessed areas on the ball outer surface that allow fluid flow past the ball exterior when it is partly open.