Abstract: A hydrostatic transmission comprising a closed loop system incorporating a hydraulic pump and a hydraulic motor driven by the pump has an accelerator for the motor drive shaft which sets the maximum delivery pressure of the pump, and control means which acts to vary the relative volume displacement of the pump and the motor to maintain the pump delivery pressure at the maximum value determined by the setting of the accelerator. Thus, the closed loop system maintains a substantially constant maximum pressure throughout the flow range, and since the output torque of the motor drive shaft is proportional to this system pressure a true acceleration control is achieved. The relative value displacement of the pump and the motor may be influenced by the low pressure of delivery of the pump on overrun of the motor shaft and by a spring loaded braking valve adjustable by a pedal control to provide for braking of the motor drive shaft.

Abstract: A limited torque, positive drive transmitting arrangement employs a leaf chain and a fluted pulley which co-operates therewith. The positive drive is transmitted via engagement of the leaf chain link edges with the specially formed pulley flutes, and the leaf chain is modified to ensure that the consequential loading of the link edges and any resulting damage thereto is prevented from interfering with the proper articulation of the chain in passing round the pulley.

Abstract: A hydraulic motor having a multiple cam designed to provide a constant torque output at high load and low speed, taking into account torque dissipated in friction in the motor.

Abstract: Compact damper apparatus for controlling the opposite runs of an endless driving chain passing about a sprocket wheel comprises a pair of oppositely movable spring influenced plungers working in hydraulic fluid filled cylinder bores intercommunicating through a restricted passage. To compact the apparatus, and yet allow it to be mounted with the plungers in an inclined position, the springs are housed in part within the plungers and a single air bleed hole is provided at the highest level inside the hollow interior spring housing part of the uppermost plunger, opening into the plunger/cylinder bore clearance. The proper positioning of this hole allows trapped air which otherwise adversely affects the damping characteristics, to be forced out along the clearance when the apparatus is initially operated, and yet prevents any air being sucked back into the system.

Abstract: A sprag clutch utilising the principles of U.S. Pat. No. 3,651,908 has an improved energising spring arrangement in which the individual sprag energising springs are mounted on intermediate portions of bars forming part of the sprag retainer assemblage. The bars define with end ring parts of the retainer, separate compartments, one for the outer end of each sprag, end portions of the bars acting to position the sprags circumferentially, and the energising springs extend inwardly from the bars. The arrangement allows more sprags to be accommodated in a given diameter and, conveniently, the retainer is made in two identical annular parts which clip together.

Abstract: In a sprag clutch having individual energising springs, one for each sprag, in which the forces on the sprags during outer race overrunning give rise to only a small rubbing load between the sprags and the clutch inner race at all outer race overrunning speeds within a designed limit, without nevertheless lifting off the clutch inner race, thereby limiting wear on overrun of the clutch, the sprags and the springs are staggered whereby each pair of adjacent sprags of said ring of sprags are offset relative to one another axially of the assemblage, and likewise the pair of springs associated with them, the sprags being shaped and arranged to interengage with one another between the springs to limit the tilt of the sprags in the driving phase of the clutch.

Abstract: A sprag clutch utilizing the principles of U.S. Pat. No. 3,651,908 has an improved energizing spring arrangement in which the individual sprag energizing springs are mounted on intermediate portions of bars forming part of the sprag retainer assemblage. .Iadd.The retainer is made in two identical annular parts which clip together. .Iaddend.The bars define with end rings parts of the retainer, separate compartments, one for the outer end of each sprag, end portions of the bars acting to position the sprags circumferentially, and the energizing springs extend inwardly from the bars. The arrangement .Iadd.facilitates the manufacture and assembling of the assemblage and .Iaddend.allows more sprags to be accommodated in a given diameter. .[.and, conveniently, the retainer is made in two identical annular parts which clip together..].