Abstract: An improved rotory positive displacement blower (10) of the Roots-type with reduced airborne noise and superior efficiency. The blower includes a housing (12) defining generally cylindrical chambers (32, 34) having cylindrical wall surfaces (20a, 20b) and containing meshed lobed rotors (14, 16) having the lobes (14a, 14b, 14c, 16a, 16b, 16c) thereon formed with an end-to-end helical twist according to the relation 360.degree./2n, where n equals the number of lobes per rotor. Preferably, n equals three. The blower housing (12) also defines inlet and outlet ports (36, 38) and the intersections of wall surfaces (20a, 20b) define a cusp (20d) associated with the inlet port (36) and a cusp (20e) associated with outlet port (38). The inlet and outlet port openings are skewed in opposite directions to increase the time the top lands of the lobes are in sealing relation with cylindrical walls (20a, 20b) of chambers ( 32, 34).

Abstract: In an in-tank type motor-driven pump actuated by feeding a power from the outside of a pump casing through an external conductor, an end of the external conductor is extended inside the pump through a through hole formed in an upper motor cover; the external conductor is held in the through hole by a supporting member, and the end of the conductor is directly or indirectly connected to a brush for the motor.

Abstract: A tiltable tricycle comprises a body frame, a single front wheel steerably supported on a front portion of the body frame, a power unit mounted on a rear portion of the body frame and including at least an engine, a joint case connected to the power unit for vertical angular movement, a rear axle support case connected to the joint case for lateral rolling movement, a rear axle assembly rotatably supported on the rear axle support case, a pair of rear wheels coupled to the rear axle assembly, respectively, and a shock absorber disposed between the body frame and the joint case.

Abstract: A pressure-operated valve is provided, particularly for use with a downhole pump of the fluid-driven, successive-stage, bladder type. Such a pump includes a plurality of pump and transfer modules. The pump modules have bladders which are operated by fluid, preferably gas, under pressure supplied through two separate internal passages in the modules to pump liquid upwardly through transfer modules. The pressure-operated valve is located below the bottom of the pump module and normally closes off the two gas passages. When gas under pressure above operating pressure is supplied through one of the passages, to establish a sufficient pressure differential between the passages, the valve opens to connect the passages. Heated gas can then be circulated to increase the temperature of internal oil passages extending through the modules to prevent paraffin formation. The two gas circuits can also be connected to enable removal of condensate.

Abstract: Water supply system comprising a unit for converting the wind energy into kinetic energy, a unit for converting the kinetic energy into another usable form of energy and a unit for supplying water driven by that usable form of energy. According to the improvement, the unit for converting the wind energy is a wind motor (1) having rotor blades (41) and a control mechanism (42) for constant load on the rotor blades (41) independently from the wind intensity, the unit for converting the kinetic energy is a device for compressing the air to a pressure greater than that of the atmosphere and the unit for supplying water comprises a natural or artificial source of water such as a well (21) or a container operated by pressurized air and structure for temporary storage of the water and for controlling the water bailing from the source of water.