GB713513A - An improved automatic pre-selective mechanism for change speed gears, particularly for motor vehicles - Google Patents

Abstract

713,513. Controlling change-speed gearing. MASSAROTTI, M. July 31, 1952 [May 29, 1952], No, 19379/52. Class 80 (2) In change-speed gearing wherein a shaft 218 is turned to engage a projection 24 with a gearrod 116, 118 or 120 and then moved axially to engage a gear, the gears are pre-selected by vehicle speed-responsive means acting through a lever 104 on a piston valve 201 controlling supply of pressure fluid.to cylinders 210, 211 with spring-loaded pistons 212, 220 the positions of which determine the subsequent axial and turning movements respectively of shaft 218, an engaged gear being disengaged, after disengagement of the clutch, on depression of the clutch pedal 70, shaft 218 then turning in the predetermined direction to engage the projection 24<SP>1</SP> with the pre-selected rod 116, 118 or 120, and, on release of the pedal .70, shaft 218 moving axially to engage the pre-selected gear, followed by engagement of the clutch. Piston 212 effects axial movement of shaft 218 through opposed springs 214 and arms on a shaft 216. Piston 220 is connected through lever 16<SP>1</SP>, opposed springs 132 and rod 128 to a member 34' having recesses 142, 144 co-operating with pins 112, 114 on a disc 50<SP>1</SP> secured to shaft 218. The lower end of member 34<SP>1</SP> is pivoted to one arm of a lever 146, the other arm of which is connected, with lost motion, to pedal 70. A projection 223 on member 34<SP>1</SP> co-operates with stops 88<SP>1</SP>. A manuallyoperable arm 224 is connected by a spring 225 to a co-axial cam 226 which in turn is connected by a spring 230 to a co-axial plate 228, the members 226. 228 having pins 227, 229 between which extends a prolongation 60<SP>1</SP> of member 34<SP>1</SP>. The cam 226 co-operates with a lever 232, one arm of which has a lost-motion connection 234 to an arm on shaft 216 and the other arm of which is loaded by a spring 237 which tends to maintain projection 24<SP>1</SP> in engagement with the reverse rod 120. As shown in Fig. 1, the vehicle is stationary, no fluid being supplied to cylinders 210, 211, the clutch is disengaged, and arm 224 is in the "neutral" position F. In this condition, the pins 227, 229 hold member 34<SP>1</SP> vertical, out of engagement with pins 112, 114, so that no gear is engaged, but springs 132 are loaded, tending to turn member 34<SP>1</SP> anti-clockwise, and springs 214 are also loaded, tending to turn shaft 218 to bring projection 24<SP>1</SP> into engagement witt rod 116. For forward speeds, arm 224 is moved to "forward" position E, which causes cam 226 and plate 228 to turn into the position shown in Fig. 5, in which first gear is engaged and second gear is pre-selected. This movement allows member 34<SP>1</SP> to move anti-clockwise by the action of the springs 132 so that recess 142 engages pin 112. The movement of cam 226 has depressed lever 232, allowing shaft 218 to be moved by springs 214 to cause projection 24<SP>1</SP> to engage rod 116. On now releasing pedal 70, member 34' is moved upwards, turning disc 50<SP>1</SP> clockwise to engage first gear. As the vehicle accelerates. valve 201 moves down and' supplies fluid to cylinder 211. Piston 220 moves down, loading the springs 132, the member 34<SP>1</SP> being held at this time by its projection 223 engaging against stop 88<SP>1</SP>. On depressing pedal 70, member 34<SP>1</SP> moves down, disengaging the first gear and disengaging from stop 88<SP>1</SP> so that springs 132 now cause recess 144 to engage pin 114. On releasing the pedal 70, member 34<SP>1</SP> moves upwards and turns disc 50<SP>1</SP> anti-clockwise to engage second gear. On further acceleration, cylinder 211 is vented, loading the springs 132, while fluid is supplied to cylinder 210, loading the springs 214. Member 34<SP>1</SP> is held at this time by projection 223 engaging against stop 88'. On depression of pedal 70, second gear is disengaged, recess 142 engages with pin 112 and projection 24<SP>1</SP> engages rod 114, the lost-motion at 234 allowing this. On release of pedal 70, third speed is engaged. For fourth speed, both cylinders 210, 211 are supplied with fluid. If the arm 224 is moved back to "neutral" position F, any engaged gear is disengaged on depression of pedal 70 and the parts return to the Fig. 1 position. If arm 224 is moved to "reverse" position and the pedal 70 depressed, the projection 24' engages with the rod 120 and member 34<SP>1</SP> is turned clockwise by pin 227, so that, on release of the pedal, rod 120 is moved to engage reverse gear. Projections 246, 245 on levers 104. 224 co-operate with fixed contacts to operate electric lamps showing preselected and engaged speeds. The pedal 70 may be operated automatically by a servomotor controlled by the pre-selecting means. Specifications 668,951 and 705,419 are referred to.