Patent GB-190822905-A (GB)
Title: Improvements in Variable-speed Gearing.
Inventor: NEWMAN JOHN GLEN
Filed: 1908-10-28
Granted: 1909-09-16
Abstract: 22,905. Newman, J. G., and Head, S. J. Oct. 28. Motor road vehicles.- Relates to variable-speed gearing of the class in which toothed wheels are brought into driving relation by friction clutches operated by oil from a pump constantly driven from the engine. The driving-shaft 32, Fig. 3, is rotatably secured to gears 33,34,35 which mesh with gears 133, 134, 135 loose upon the driven shaft 96. When the gears 133, 134, 135 are clutched to the shaft 96 in turn, three forward speeds are effected. To effect reversal, a gear 37 is provided connected by a sleeve to the gear 35. On sliding the gears 35, 37 to the left of Fig. 3, a flange 38, Fig. 6, on the latter engages the edge of an intermeshing idler 39 and thrusts it against the action of a spring 42 into mesh with the gear 135. This operation is effected by a pedal 48, Fig. 1. The clutches are constructed as shown in Fig. 8. Arranged around the shaft 96 are cylinders 126, 127, 128 containing annular pistons 129. When oil is driven into one of the cylinders 126 &c., the corresponding piston 129 is thrust outwards so as to grip the corresponding loose gear 133 &c. Relative rotation of the parts is prevented by pins 131, Fig. 8, engaging slots 132 in the cylinder 126. An eccentric 50, Fig. 3, keeps a plunger constantly working in a pump barrel 52, Fig. 5. Oil is present in quantity within the gear. case 30, and the pump acts normally to draw oil in through a valve 68, Fig. 5, and to drive it out again through a passage 53. When the passage 53 is closed by a cock 56, the oil is driven into a chamber 75, where it gathers the pressure necessary to work the clutch pistons. A safety-valve 55, Fig. 5, is provided. A nipple 76 on the chamber 75 is connected by a pipe 77 to a pressure-gauge 78, Fig. 1. Oil is delivered from the chamber 75, Fig. 5, through a passage 74 to a pipe 79, Fig. 3, which divides into two branches 80, 81. The branch 80 delivers the oil back to the casing 30 under the control of a cock 82, which is opened at will by means of a pedal 85, Fig. 1. The branch 81, Fig. 3, is connected by a flexible pipe 86 to an elbow 87 and the ' regulator' for guiding the pressure oil to the clutch to be operated. This 'regulator' comprises a tube 88 sliding in a cylindrical chamber 95 in the body of the shaft 96. The pressure oil passes through the tube 88 and emerges at an orifice 91, Fig. 11, between two cup-leathers 93 upon a piston valve 89. According to the position of the valve 89, the oil is forced along one of the tubes 123, 124, 125, Figs. 3 and 8, into the corresponding cylinder 126 &c. A yoke 99, Fig. 3, on the end of the tube 88 works on a guide 100 under the action of levers and links 101, 103, 104, Fig. 1, connected to a vertical rod 105 having a crank handle 106. The handle 106 may work across a sector 109 upon the steering-column 110 of a motorcar. To change the gear, the clutch in action is released by depressing the pedal 85, Fig. 1, the handle 106 is turned as required, and the pedal 85 released. An essential feature is the means for controlling the valve 56. A rod 57, Fig. 3, ascends from the valve 56 and is connected by a crank 58 to the plunger 59 of a pneumatic cylinder 61. A. spring works in the cylinder 61 against the pressure of air, which is supplied through a tube 64 from a compression bulb 65, Fig. 1, upon the steering-wheel 66. Figs. 23 and 25 show alternative controlling-arrangements. Pressure upon a pneumatic plunger 195 causes oil to be pumped into the regulator,' and turning the handle 106 moves the regulator' as before. Modified forms of 'regu- 'lator' are also described. In Figs. 20 and 21 is shown a rotary plug 184 having passages 187, 186 for delivering oil from an inlet 182 to any one of three outlets 174, 175, 176 leading to the friction clutches. A second passage 188 is provided leading to a discharge port 183.