Patent GB-628248-A (GB)
Title: An automatic hydraulically-operated change-speed device
IPC: F16H39/16
Filed: 1945-09-05
Abstract: 628,248. Hydraulic gears. SAUSSARD, L. Sept. 5, 1945, Nos. 22847 and 22848. Conven- .tion dates, Aug. 25, 1942. and Dec. 4, 1942. [Class 69 (ii)] In an automatic change-speed device comprising a volumetric driving pump having a variable cylinder capacity, driven by a constant speed, constant - torque, prime mover, and a volumetric driven pump having a variable cylinder capacity, driven by the liquid forced by the driving pump and coupled with a driven shaft whose resisting torque is variable, a rocking lever formed with longitudinal passages for the circulation of the liquid between the driving and driven pumps automatically controls the variations of the driving pump cylinder according to the variations of the resisting torque. The pumps may be of the kind described in Specification 456,946, [Group XXVIII]. The cylinders 103 (Fig. 9) of the driven one rotate with the housing 104 carried by the driving housing 142. The pistons 102 rotate on a rocker 101, the other end of which carries a similar pump system, the rocker having passages P, P<SP>1</SP>, which communicate with passages in the pistons through radial apertures at its ends. The rocker is adapted to turn about trunnions 106 mounted in a frame 107 and is urged by a spring 131 acting on an arm 128 into a position where the assembly of pistons 102 takes a certain eccentricity with respect to the cylinders 103. The driving pump circulates liquid through passages P, p<SP>1</SP>, to the driven pump which, by reaction, causes the cylinders of the latter to rotate and consequently also the driven shaft to which they are connected. The driven shaft 116 is solid in rotation with the rocker 101 which is caused to rotate by the effect of the reaction resulting from the eccentricity of the pumps. The rocker 101 turns simultaneously with the frame 107 which supports the trunnions 106, the rotation being transmitted to the shaft 116 through a driving dog 163, 164. Resistance of the driven shaft tends to make the driven pump take up its central position but the rocker 101 turning about trunnions 106 increases the eccentricity of the driving pump and increases the flow. A position of equilibrium is established between the eccentricities of the two pumps corresponding at each instant to the relationship between the driving and resisting couples. A hand lever 132 acting on the arm 128 allows the eccentricities to be manually controlled as desired and for reverse running to be obtained. When the driving pump is in its position of maximum efficiency a mechanical clutch engages to give direct drive. The trunnions 106 are hollow and have ball valves communicating with the passages P, p<SP>1</SP> to allow automatic compensation for leakage of liquid. The Specification as open to inspection under Sect. 91 comprises also modifications wherein a turbine is used in lieu of the receiving pump. As shown in Fig. 1 (Cancelled), the driving pump 2, 3 is mounted on a rocker 1. The turbine, shown in section in Fig. 4 (Cancelled), comprises a rotor 9 and a stator 10 with cells 11 which eject liquid from the pump into channels 12 for the purpose of obtaining by reaction the rotation of the rotor rigid with the driven shaft. For reverse drive the liquid is directed through channels 13. The turbine may be replaced by a motor (Fig. 5, Cancelled) having blades 28 swivelling on shafts 30 communicating with the delivery of the pump. These diametricallypaired blades aro urged by springs such as 31, 32, or 33, to feed tangentially on to the recessed faces of the stator 29. Two motors are provided next to one another, one for forward and one for backward drive. This subject-matter does not appear in the Specification as accepted.