Patent GB-493206-A (GB)
Title: Improvements in power transmission mechanism
Filed: 1937-04-08
Abstract: 493,206. Variable - speed gearing; toothed gearing. SINCLAIR, H., and CLERK, R. C. April 8, 1937, Nos. 10066 and 10970. [Classes 80 (i) and 80 (ii)] In an internal - combustion - engine powertransmission system with hydraulic coupling and constant - mesh change-speed gear and a selector, the accelerator or equivalent power-control member is connected to the selector so that some of the gear changes are made or allowed at the time that the torque of the coupling is ceasing or reversing. A four-speed planetary gearing, as described in Specification 444,899, includes four earthed electromagnets with terminals a... d, Fig. 10. suitably connected to contacts 1 ... 4 of the selector which has a contact strip 55 with switch 112 for battery 91 or generator 93. The battery 91 is also connected through resistance 109 to a contact arm engaging contacts 101, 102 mounted on the reversing- lever 48 and connected respectively to terminals a, d. This ensures one of the forward speeds, preferably direct-drive, being engaged while the reversing-gear is operated. The selector is carried by the steering-column 53, Fig. 4, and comprises a handle 63 on a spring arm 64 mounted on a pivot 57 carrying a hair-pin spring 69 engaging studs 67, 68 fixed to the arm 64 and a contact arm 56 engaging the contacts 1... 4 and 55. Arm 56 is locked by a pivoted tumbler 60 having three notches for first, second, and third speed positions, the arm having free movement between fourth speed and neutral. The tumbler is actuated by a rod 70 pivoted to a link 75 having a cam 76 and a slot 77 engaging a pin 81 on a plate 78 linked by a rod 83 to the accelerator pedal. Pin 81 is so arranged that a slight depression of the pedal raises rod 70 and tumbler 60 sufficiently to release arm 56, further depression re-locking arm 56 until at full depression, as when changing down, pin 82 on plate 78 engages cam 76 on link 75 to raise arm 56. To facilitate gear-changing, the leading faces of the rear half of the planet-carrier teeth 44, Fig. 15, are backed-off at 114 and the trailing faces of the annulus teeth 41 at 115. Similarly, the co-opcrating faces of teeth 44 and sector teeth 45 are backed-offat 116, 117. A reversing-gear yielding the same speed on forward and reverse running may be used instead of planetary reversing-gear for railway vehicles. The jaw-clutch member 125, Fig. 16 is slidable, under control of the reverse selector 46, on helical splines 126 formed on the input shaft 30 to the electromagnetically controlled gearing. The splines assist disengagement from both forward and reverse positions. A runner brake may be used to obviate engaging a forward gear during operation of the reversing-lever. An armature disc 49, Fig. 3, is splined to and slidable on the coupling shaft 24 and co-operates with an electromagnet E connected to terminal e, the reversing- selector 46a having a middle neutral notch. Terminal e is connected to stud 102, Fig. 10, on lever 48, the full line conductors leading to studs 101, 102 being dispensed with. Specifications 285,970, [Class79 (ii)], and 365,998 are referred to in the second Provisional Specification.