Patent GB-380443-A (GB)
Title: Improvements in automatic speed change transmissions
IPC: F16H61/02
Filed: 1931-06-10
Abstract: 380,443. Variable speed epicyclic gearing. BANKER, O. H., 5548, Glenwood Avenue, Chicago, U.S.A. June 10, 1931, No. 16875. [Class 80 (ii).] Relates to variable-speed epicyclic gearing for automobiles in which automatic change of speed is effected by centrifugal clutches, means being provided to change from top speed to second at any time, to lock the gear in that speed, and to effect a reverse drive. The driving-shaft 20 is connected to a shaft 34 through a segmental centrifugal clutch 71, 74 and a roller ratchet clutch 61, 63, 64, the clutches being arranged in series. The shaft 34 carries a sun-wheel 37 and a shaft 39 a sun-wheel 40, the driven shaft 43 carrying a sun-wheel 48. The planet-carrier 42 is journalled in the casing-plate 24 and carries combined wheels 58, 59, 60. First and second speeds are obtainable with the carrier 42 stationary and the wheels 37, 40, respectively, driving. Top speed is solid, and, for reverse, the carrier is free, the gear 40 stationed, and the gear 37 driving. At first speed, the wheel 40 is driven at lower speed than the wheel 37, but when that speed is sufficient, a centrifugal clutch 81, 80 is engaged to connect the shafts 20, 39 to give second speed, the shaft 34 then overrunning the ratchet drum 61. During these operations, backward rotation of the carrier 42 is prevented, so as to provide a fulcrum, by a wheel 53 on the carrier engaging . a spiral wheel 87 on a shaft 86 connected to the casing by a one-way roller detent 89, 93, 91. For top speed, the engine is decelerated, when the carrier 42 turns forwardly and is thereby clutched to a drum 94, connected by a clutch 137 to the driven shaft 43, to lock the gearing solid. The clutch between the carrier and the drum 94 is of the centrifugally-operated ratchet type, in which a coil spring 95 normally free from the drum is connected at one end to the wheel 53 on the carrier and bears at its other end 98 on a member 100 carrying projections 101 engaging with spring and centrifugallycontrolled weights 103, outward movement of which rotates the member 100 to move the end 98 of the spring 95, which thus smoothly clutches the drum 94. In a modified form of high speed clutch, the coil and weights are carried by the drum 94, so that engine deceleration is not required, the action being wholly controlled by the speed of the driven shaft, spring-actuated balls and recesses being provided to ensure snapaction movement of the weights for clutch engagement. Manual disengagement of the clutch 137 effects change from top to second gear, overriding the automatic action. Reversal is obtained by engaging a positive brake 141 with the drum 83 on the shaft 39, to station the wheel 40, and by releasing the one-way detent 89, 93, 91 and the clutch 137 to allow the carrier 42 to reverse. The detent is manually released by rotation of the disc 142, carrying the rollers 93, by a lug on a sleeve 145 secured thereon and engageable by a plunger 196. To lock the gear in second speed for engine braking &c., the carrier 42 is prevented also from forward running under the pull of the driven shaft by a coil brake 150 which connects a drum 148 on the shaft 86 to the casing and is operated by a drum 154 engaging one end of the ceil and secured to a wheel 159 which is rotated by a rack 160 operated by a rod 205. The coil brake has such internal lost motion that, in bringing the gear to neutral position, although the one-way detent 89, 93, 91 and the clutch 137 are released, the coil brake is not engaged. Back running of the car is prevented by the use of a one-way detent 218 between the shaft 39, which would be rotated backwards by such motion, and the casing. A centrifugal clutch of the type employed for top speed may be substituted for the clutch 81, 80. Control, for normal automatic drive, neutral position, and reverse, is elfected by a sliding bar 163, Fig. 14, and, for bringing the speed from top to second, by a pedal 212, which is partly depressed to override the automatic action and fully depressed to lock the second gear for engine braking. The bar 163 is linked to a shaft 181, which carries a lever directly operating the positive brake 141 and is linked to a lever 190 which operates the plunger 196 controlling the one-way detent 89, 93, 91, and engages with lost motion a lever 200 secured to a shaft 185 which directly operates the clutch 137. The shaft 185 also turns a bell-crank lever 204, 215 which operates the rod 205 controlling the'coil brake 150 and which is slotted for engagement by a pin on a link 214 moved by the pedal 212, so that the control bar 163 can be moved independently of the pedal.