Patent GB-807303-A (GB)
Title: Improvements in or relating to automatic change-speed gears
IPC: F16H63/02
Filed: 1955-05-26
Abstract: 807,303. Change-speed gearing. EATON MANUFACTURING CO. May 26, 1955 (June 3, 1954], No. 15206/55. Class 80 (2). A change-speed gear for a motor car comprises aligned driving and driven shafts, a gear fast with the driving shaft and a gear rotatable on the driven shaft, double-acting clutch means co-operating alternatively with the two gears, and a clutchoperating servomotor actuated by the suction from the inlet manifold of the car engine, the servomotor being connected to the clutch by a link mechanism including springs tending to disengage the clutch means from both of the gears. Gearing.-A change - speed gear comprises a driving shaft 16 connected either to a hollow shaft 31 by an electromagnetic clutch 14 or to a shaft 28 by an electromagnetic clutch 13. Gears 47, 48 on the ends of these two shafts mesh gears 53, 54, rotatable on a countershaft 52 and having a free-wheel 60 between them. A gear 55, splined for rotation with the gear 54, meshes a gear 49 rotatable on but clutchable to a driven shaft 46. As shown, the gear 55 meshes directly with the gear 49, but alternatively it can be slidden axially of the countershaft 52 to engage with the gear 49 through a reverse idler (not shown). Synchron. ized positive clutches either connect the gear 47 direct to the driven shaft 46, or connect the gear 49 thereto. Ring gears 74, 75 can slide axially upon a toothed member 73 fast upon the driven shaft 46 to engage with clutch teeth 79, 77 on the gears 47, 49, respectively. Balk rings 78 have internallyconed friction faces permanently engaged on extensions 82 of the two gears 47, 49 to synchronize engagement of the ring gears 74, 75 with their clutch teeth. The ring gears 74, 75 are moved axially of the gearing by two arms 93, 94, biased to a central, neutral, position by springs 97, 98 acting on a sleeve 95 slidable upon a rod 91 moved axially to change the ratio in the gearing by engine inlet manifold suction applied to a diaphragm 88 in a servomotor 84 and working against the bias of a spring 92. With the gear 49 clutched to the driven shaft 46, energization of the electromagnetic clutch 13 gives a first low-speed ratio, while energization of the electromagnetic clutch 14 gives a second reduced ratio with the free-wheel 60 over-running. If the gear 49 is then declutched from the shaft 46 and the gear 47 is clutched thereto, energization of the electromagnetic clutch 13 gives direct drive. A centrifugal governor 101, controlling the changespeed gearing, is driven by the shaft 46. Control.-An electric control circuit for the gear is shown, comprising accelerator controlled switches and a switch controlled by the centrifugal governor 101 connected to the output shaft 46 of the gear. Power for the circuit is provided by a generator 113 connected through the usual cut-out 117 to an ignition and starter switch 119 and to an accumulator 110. The governor controlled switch comprises a group of relatively stationary contacts 129-131 on a carrier 132 and a movable contact 133 on an arm 134 of the governor. The carrier 132 is connected by a bell-crank lever 137 to a rod 136 slidden axially by movement of the accelerator pedal 109 to pivot the butterfly valve in the engine inlet manifold 89. A solenoid 139 controls the movement of a multiple switch 106, comprising switches 144, 145 and 146. A solenoid 148 controls a multiple switch 107, comprising switches 151 and 152. A switch 108 is connected to the rod 91 effecting the engagement of the synchronized positive clutches in the change-speed gear, and controls the supply of current to the coils 20, 21 of the electromagnetic clutches 13, 14. Switches 160-162 are associated with the accelerator pedal 109. The engine intake manifold is connected to the servomotor 84 through a solenoid-actuated valve 163 and a suction tank 164. As shown in Fig. 2, the control circuit is in the low gear position. The multiple switch 106 has been energized to the position shown in which switches 140, 142 and 143, normally close, have been opened and the normally open switch 141 has been closed. The circuit of the electromagnetic clutch 13 is then prepared so that its solenoid 20 is energized as soon as the accelerator 109 is depressed to close the switch 160. As the car moves off and its speed increases, the governor 101 moves the contact 133 into engagement with the contact 129 thereby completing a second energizing circuit for the solenoid 139 to a conductor 174. The solenoid 20 of the clutch 13 is then energized from the battery 110 through a resistor 171 and circuit comprised by parts 172, 126, 173, 160, a resistor 175, and parts 176, 141, 177. The resistors 171, 175 reduce the flow of current to the solenoid 20, so that the clutch 13 can slip. As the accelerator pedal 109 is further depressed, the switch 161 is closed to short-circuit the resistor 175 and increase the flow of current to the solenoid 20, so that slipping in the clutch 13 is decreased or eliminated. As the speed of the vehicle still further increases, the governor 101 shifts the contact 133 to the contact 130, thereby supplying current to the solenoid 148 of the multiple switch 107. This opens the switch 151 and closes the switch 150. Simultaneously, the movement of the contact 133 out of engagement with the contact 129 deenergizes the solenoid 139, thus closing the switches 140, 142 and 143. Closing the switch 140 short-circuits 'the resistor 171 so that the electromagnetic clutch 13 is fully energized. Opening of the switch 141 opens the energizing circuit for the solenoid 20 of the electromagnetic clutch 13, and closing the switch 150 closes the energizing circuit of the solenoid 21 of the electromagnetic clutch 14. The second or intermediate speed is therefore engaged. Current to the solenoid 21 of the clutch 14 then flows through parts 161, 176, 179, 150, 180, 155 and 181. As the speed of the car increases further, the governor 101 shifts the contact 133 from the contact 130 to the contact 131. This closes the circuit for the solenoid 167 of the valve 163 to open the valve 163. The servomotor 84 is thus connected with the engine inlet manifold 89. The servomotor 84 then shifts the synchronized positive clutches to engage the output shaft 46 with the gear 47 for direct drive. At the same time, the switch 108 is actuated to deenergize the electromagnetic clutch 14 and energize the electromagnetic clutch 13. To change down from direct drive to second ratio, the accelerator pedal 109 is kicked-down to open the switch 162 and de-energize the solenoid 167 of the valve 163, allowing the valve 163 to close. The servomotor 84 thus becomes inoperative, whereupon the spring 92 shifts the gear to the second ratio. Simultaneously, the switch 108 is actuated, the electromagnetic clutch 13 is de-energized and the magnetic clutch 14 is re-energized. When the accelerator pedal 109 is released, the switch 162 is re-closed to reenergize the solenoid 167 and re-connect the servo-device 84 to the engine inlet manifold 89. The gear is then shifted back to direct drive.