Patent GB-449866-A (GB)
Title: Automatic infinitely variable speed transmission especially for motor vehicles
IPC: F16H29/22
Filed: 1934-12-31
Abstract: 449,866. Variable - speed gearing; brakes; flexible shafts. NAGY, P. S., VI. Gyongyosi ut 2.II. 15, and CSARADA, H. VON, II. Branyiszko ut 13/a, both in Budapest. Dec. 31, 1934, No. 37377. Convention date, Dec. 30, 1933. [Class 80 (ii)] [See also Group XXXIV] An infinitely-variable gear comprises a number of torsion springs secured to the driven member, the free ends being connected to locking devices and adapted to be displaced, so as to strain the springs, by a cam surface on the driving member. The fly-wheel 1 of the engine has a hub 2 to which is slidably splined a cam drum 4, the axial movement of which is limited, the drum being urged towards the fly-wheel by a spring 5. Bell-crank levers 10 pivoted in brackets 9 on the drum carry on one arm a weight 11, the other arm bearing against a ring 13 rigid with the drum. Upon increase of speed, centrifugal force of the weights causes the cam drum to move to the right. The drum has a cam 15, the highest part 15<1>, Fig. 4, of which is narrower than the foot and is concentric with the drum, the widest part of the cam being narrower than the drum to leave a conical edge 4<1>. Torsion springs 20 have their rear ends secured to a plate 21 on the driven shaft 17, the front or free ends being rotatably mounted in two plates 18, 19, also secured to shaft 17, and secured to arms 16 which carry shoes 23 or rollers 24, Fig. 2, adapted to be engaged by the cam. When no torque is being transmitted, the shoes or rollers ride on the conical edge 4<1>, but as the speed increases, the drum is moved to the right to cause the cam to engage the rollers and strain the springs. Each driving arm is connected by a link 25 to a locking device consisting of a slide 26, Fig. 5, having a tapered middle portion 27. The slide is guided by strips 33 moving in grooves 31, 32 of two fixed rings 29, 30 and spring-pressed rollers are located between the part 27 and the rings 29, 30. The mechanism is enclosed in a casing 60, Fig. 1, filled with lubricating oil, a passage 65 serving to conduct oil thrown out through a port 66 into the interior of the cam drum through port 67. In a modification, the arms 16 are integral with the torsion rods 20. In a further modification, each torsion rod 20 is replaced by a bundle of smaller rods. In a still further modification, Fig. 9 (not shown), the torsion rods are replaced by coaxial helical springs, permitting of a shorter mechanism. Two modified forms of locking device are described with reference to Figs. 11, 12 (not shown). During swinging of the arms 16 by the cam, the springs are strained and the slides 26 are moved. When the cam disengages the shoe or roller, the respective spring remains strained. Increase of engine speed causes movement of the cam drum and a higher part of the cam to engage the arms. On throttling the engine, the shoe or roller remains on the part of the cam by which it was being actuated. If shaft 17 becomes the driver, one of the arms 16 bears against the radial end surface of the cam and the cam drum is rotated. Power is transmitted from shaft 17 to shaft 171 by gearing comprising a shiftable gear 71 adapted to couple teeth 68 on plate 19 with teeth on a sleeve 70, or engage a gear on a countershaft 69.