Patent GB-421763-A (GB)
Title: Improvements in or relating to variable speed transmissions for use with internal combustion engines
Filed: 1934-01-06
Abstract: 421,763. Variable speed gearing. BARTHELEMY, P., 214, Rue de Rivoli, Paris. Jan. 6, 1934, No. 567. [A Specification was laid open to inspection under Sect. 91 of the Acts, July 12, 1934.] [Class 80 (ii)] [See also Groups XXXI and XXXIII] Motor-vehicle variable-speed gearing is automatically controlled by movement of the resiliently-mounted internal-combustion engine a, under the influence of torque-reaction, about a longitudinal axis b, such as that of the crankshaft, against resilient supports such as one or more leaf-springs f. This controlling-factor may also be assisted by the speed of driving or driven shafts, engine-suction, the setting of the accelerator-pedal and the resisting torque. The engine-movement may act through an electric, suction, or pressure relay. The variable-speed gear may be of the type operated by sliding wheels, friction or electromagnetic clutches, or of the continuously-variable friction or cone-pulley type. As shown in Fig. 1, the tilting-movement of the engine acts, through a spring g, to swing an electric contact arm j over contacts i leading to electromagnetic clutches (not shown). Movement of the arm j is damped by a dashpot h. A centrifugal governor y, driven by the crankshaft b, acts, through a lever y<2> to oppose the torque-reaction. The useful engine-movement may be magnified by a system of levers. In the form shown in Figs. 2 and 3, the tilting of the engine a acts, through a toothed sector m and pinion o, to turn a shaft p carrying a number of cams q<1>, q<2>, which slide toothedwheels s<1>, s<2> of the variable-gear. An additional cam q automatically disengages a main-clutch a during changes. A spring-loaded ball l<2> holds the sector m in gear-positions. The compression of the spring l<3>, which holds this ball l<2>, may determine the speed at which a change occurs, and it may be adjustably controlled by the accelerator-pedal or other remote control. Fig. 4 shows a precessional friction-gear automatically controlled by the driving and resisting torques in the manner described in French Specification 687,030, and French Patent of Addition 37884. A roller t<3>, slidably splined on the driving shaft a<1>, engages a pair of discs t<1>, t<2>, mounted on shafts t, universally connected to each road-wheel. The discs t<1>, t<2>, are carried in a frame u pivotally supported on a spring u<2> and are pressed together by a spring u<1>, the arrangement being such that any variation in the resisting torque causes one of the discs to rise and the other to fall, the roller then precessing along the shaft a<1> to a fresh equilibrium position, whereupon the discs return to the normal position. The frame u is also acted upon by the driving torque, the reactionary movement of the engine a operating thereon through springs f<1> or f<2> and a lever w, mounted on a stationary pivot w<2>, having a pin-and-slot connection w<3> with a lever x, secured to the pivotal point x<1> of the frame u. The driving torque thus provides a force F acting on one end of the lever wand the resisting torque provides a force F<1> acting on its other end. The leverarms are so arranged that these forces are equal, but when there is a variation in either the driving or resisting torques, the inertia of the engine flywheel permits one force F or F<1> to vary before the other. The lever w is then unbalanced and the frame u tilts until the roller t<3> finds a fresh equilibrium position. In a modification, Fig. 5, not shown, of this form the accelerator-pedal is connected through a telescopic spring-link with a part which swings with the engine a under torque-reaction, and conveys its movement to the point x<1> of the frame u, through springs f, or f as in Fig. 4, and further levers, links and universal joints. In a further modification, Fig. 6, not shown, the springs f<1>, f<2>, are omitted and the springs in the telescopic-link of the accelerator-pedal act in place of them. In this form the lever-arm of the engine-movement is only nine-tenths of that of the resisting-torque, the remaining one-tenth being provided by the pressure on the accelerator-pedal. In all forms of the friction-gears, the forces are reversed when the engine is transmitting braking-torque. The Specification as open to inspection under Sect. 91 states that the control may be used to vary the incidence of variable-pitch airscrews. This subject-matter does not appear in the Specification as accepted.