Patent GB-440757-A (GB)
Title: Improvements in or relating to change-speed transmissions of the planetary gear type
IPC: F16H63/30
Filed: 1935-01-10
Abstract: 440,757. Controlling change-speed epicyclic gearing. CHRYSLER CORPORATION, 341, Massachusetts Avenue, Highland Park, Michigan, U.S.A.-(Assignees of Patterson, H. F.) Jan. 10, 1935, No. 920. Convention date, Jan. 25, 1934. [Class 80 (ii)] [See also Group XXIX] Epicyclic change-speed gearing suitable for vehicles is controlled from a manual lever 127<1>, Fig. 1, which turns a selector valve 67, Fig. 6, which sends pressure oil to actuate alternatively brakes 10, 11, 12, Fig. 3, or a solid-driving cone clutch 13. The valve 67, Fig. 6, has a hollow stem 66 passing down through a bushing 65 with an annular chamber 76 containing pressure oil. The oil passes up through a vertical bore 71, along a horizontal passage 72, and downwards to an outlet port 86 adapted to register selectively with an arcuate series of ports 88, 90, 92, 94, Fig. 3, in a horizontal plate 87. A series of passages 91, 93, 95 shown in Fig. 2 leading up to a cap D which contains the selector valve are normally full of oil up to the brims which coincide with the ports 88 . . 94 in the plate 87 so that air does not get mixed with the pressure oil. The valve 67 is turned by a lever arm 68 connected by a rod 70, Fig. 1, a lever 142 and rod 132 to the hand lever 127<1> which is moved over a locking quadrant 126. The tendency of the pressure oil to lift the horizontal arm 72 of the valve 67 off its seat 87 is corrected by arranging that the arm is pierced for a cup or piston 97 which is thrust upwards against the under surface of the cap D. The piston 97 is larger in area than the valve opening 86 so that there is a good oil seal between the arm 72 and the seat plate 87. The brake 10 for the first speed is engaged by thrusting apart a pair of pistons 43, 44, Fig. 7, between which oil is admitted from the passage 93. These pistons act through levers 47 and links 50 to thrust together the free ends of the brake band 10. The middle part of the band is supported upon spaced lugs 23, 24 connected by the floating linkage shown to anchoring pins 33, 34. The first-speed cylinder 41 and the reverse cylinder 42, Fig. 3, are large compared to the cylinder 40 for operating the second-speed brake 11, the torque on which is not so great. There are a pair of separated pistons in the cylinder 40, but a single piston 59 in a cylinder 60 for actuating the high or third speed clutch 13. When the valve 67 is turned from the neutral position shown in Fig. 3 past the ports 92, 90, for first and second speeds to the port 88, oil raises the piston 59 and through a cranked lever 55 thrusts the clutch 13 into engagement with one of the gear drums 17, effecting solid driving. Two pipes 73, 74 are shown in Fig. 6 by which pressure oil may reach the valve chamber 76. The pipe 74, which is sealed by a check valve 77, leads past a turn cock 79, Fig. 4, from the delivery 80 of a gear pump E driven through skew gearing 114, 115 from a shaft 116 which is the clutch shaft and is driven from the engine A, Fig. 1, through an hydraulic engine clutch B. The pump E, Fig. 4, draws oil from a sump 102 through a pair of aligned openings 105, 106 and a waisted valve 108 which has a piston end 110 extending into the delivery 80 of the pump. Excessive pressure of pumped oil thrusts in. the piston end 110 so that the waisted valve 108 cuts off further supply. The cock 79 can be turned through a cable 79g from a button 79c on the dash so as to vent the oil back to the sump without passing through the pipe 74 to the selector valve 67, Fig. 6. The pipe 73 may then be caused to supply oil from an alternative source. This pipe leads to a cylinder 83, Fig. 4, which is constantly open at 112 to the oil in the sump 102. A piston 117, Fig. 2, in the cylinder 83 is connected to a pedal lever 123, Fig. 1, so that depression of the pedal forces oil past a check valve 84, Fig. 2, and up the pipe 73 and into the valve chamber 76, Fig. 6. To change speed when the cock 79, Fig. 4, is open, all that is necessary is to move the handle 127<1>, Fig. 1. When the cock 79 is closed, it is necessary, in addition to work the pedal 123. An arrangement is described with reference to Figs. 8, 9, and 9A, not shown, in which the engine-pump source of oil is dispensed with, the pedal source being the only one. In Fig. 6A is shown means for facilitating the turning of the selector valve 67 of Fig. 6 by relieving the pressure in the passages 71, 72. Between the control lever 68<1>, Fig. 6A, and the valve stem 66<1> is a lostmotion connection in which a spring finger 153 on the lever rides up on cams rigid with the stem. The effect of this is that when effort is applied to the hand lever 127<1>, Fig. 1, a cam segment 154, Fig. 6A, turns under and raises a poppet relief valve 155 so that the selector valve can be set without resistance.