Patent GB-1089437-A (GB)
Title: Improvements in or relating to gear change control device for automotive vehicles
IPC: F16H61/02
Filed: 1964-10-27
Abstract: 1,089,437. Controlling change-speed gears; ratchet gearing. G. GUIBEAUD. Oct. 27, 1964 [Oct. 28, 1963], No. 43831/64. Headings F2D and F2Q. A control for a stepped change-speed gear comprises a rotary switch or distribution valve moved stepwise in opposite directions for upshift and downshift by separate manually or automatically operated selector switches A, B respectively, to control energization of servomotors actuating ratio-shift rails. The main clutch and in most cases the engine throttle are actuated coincidentally during shifts, double declutching being used in some embodiments. Function summary.-The Specification discloses eight separate embodiments for gearshift control, and one device for main clutch and throttle control, Fig. 3, which automatically provides engine idle during upshift and an intermediate engine speed during downshift, with graduated rates of throttle movement and with double declutching. In all embodiments, the selector switches A, B are controlled by foot-operated push-buttons mounted adjacent to, or on the sides of, the clutch pedal so that depression of one of them for ratio shift coincidentally depresses the clutch pedal. Engagement of the clutch is normally driver controlled. Embodiments 1 to 6 provide manually controlled shifts, while embodiments 7, 8 additionally provide automatic shifts in response to vehicle speed and engine torque as manifested by accelerator position or inlet manifold depression. Ratios include one or more overdrives in addition to the usual reduction ratios. Embodiment 1, Figs. 7, 8. A rotary distributer switch controls individual servos for each shift rail, the control circuit being coupled to the clutch/throttle control of Fig. 3. Embodiment 2, Figs. 1, 2, is a simpler form requiring manual power for coincidental clutch and throttle control, intended for constant mesh gear-boxes. In embodiment 3, Figs. 4-6, the rotary distributer controls power driven cams acting directly on the shift rails. In embodiment 4, Figs. 9-15, 18, 19, the control is of the type wherein a selector finger is given selecting and establishing movements in planes at right angles and includes a doubleacting servomotor for the establishing movements in conjunction with solenoid-operated stops controlling the cross-shift movements. Embodiment 5, Fig. 16, uses separate solenoids for cross-shift and gear establishing movements. Embodiment 6, Fig. 17, uses separate fluid pressure or suction servomotors controlled by solenoid valves or direct solenoid operation, for cross-shift and gear establishing movement. Embodiment 7, Fig. 20, provides manually controlled shifts or automatic shifts under the control of an adapted speedometer which provides visual indication of the ratio engaged, and, when used for manual control, visual and audible warning of the need for upshift or downshift. Embodiment 8, Fig. 21, provides manually controlled shifts or automatic shifts with manual override on rapid movement of the accelerator pedal. Throttle and clutch control (Fig. 3).-For moving away from rest, the clutch is manually controlled. The throttle control linkage comprises a floating lever 42 pivoted intermediate its ends to the throttle linkage and pivoted at one end to a link connected by springs at 40 to the accelerator pedal, and at the other end to a piston rod 43 carrying an armature 45 and a piston 46 slidable in a fixed cylinder 44 subject to controlled bleed to provide two rates of throttle movement. For upshift, closure of the switch A closes a switch 69 to energize a solenoid 41 to lock the manual control of the throttle, and energizes a solenoid 71 to close a switch 70 which, with a switch 51 moved by a solenoid 52 energized by the switch A to earth a contact 49, completes the circuit of a solenoid 48 which attracts the armature 45 to close the throttle rapidly. As the rod 43 reaches the end of its stroke, an earthed ramp 66 thereon meets a contact 68 to energize a solenoid 65 for clutch disengagement. Also, a blade 60 engages a contact 57 which, through a switch 56, energizes a solenoid 54 to close a valve 53 in the end of the cylinder 44 to reduce the bleed to that provided by adjustable vents 61, 62. When, during gearshift, the superseded ratio has been disengaged, the solenoid 71 is de-energized, de-energizing the solenoid 48 to allow momentary throttle opening at the slower rate, and clutch engagement. After a short interval, the solenoid 71 is again energized so that the throttle is closed rapidly, cylinder compression opening the now de-energized valve 53, and the clutch again disengaged. Following engagement of the new ratio, the circuits are de-energized, the clutch is re-engaged, and the throttle opened at the slower rate and returned to manual control. For downshift, closure of the switch B energizes a solenoid 72 to close a switch connecting the clutch solenoid 65 to a contact 67, and a solenoid 58 to cause the switch 56 to complete the circuit of the solenoid 54 through a contact bar 59 and the blade 60, to close the valve 53 so that the throttle will be closed at the slower rate. Only a part of the solenoid 48 is energized, through a contact 50 and the switch 51, so that the throttle is only partly closed, the clutch being disengaged as the ram 66 meets the contact 67 immediately the throttle starts to close. The blade 60 leaves the bar 59 just before the rod 43 stops at the partly closed throttle position, to open the valve 53, allowing rapid initial opening of the throttle. The solenoid 71 is momentarily de-energized during the shift, as in upshift. For manual clutch control, the solenoid 65 is earthed through a switch closed by either selector push-button and a manual switch whose control also holds open the switch 70. In an alternative embodiment, the manual and automatic throttle controls are linked to separate throttle valves arranged in series, the manual one being locked fully open during shifts, and the automatically controlled one being fully open at other times. Embodiment 1 (Figs. 7, 8).-Fig. 7 shows three alternative shift servo systems and Fig. 8 shows a fourth. In each case, energization of one or other of two brushes 134 via contacts 2 of the rotary switch 1 causes movement of the shift rail 25 to a respective gear-engaged position, while energization of a brush 128 via a brush 124 and a stud 127 causes movement to a central neutral position. A spring-engaged, solenoid-released detent 135 is provided for each shift rail. In Fig. 7, the right-hand shift rail 25 is moved to neutral by a coil 119 and to one or other gear engaged position by respective coils 120. All the coils are de-energized when a selected position is reached. The left-hand rail 25 is moved by oppositely rotating electric motors 141 acting through a screw-and-nut drive. For neutral selection, the relevant motor 141 is stopped when the brush 128 engages an insulated strip at the neutral position. The middle rail 25, which may be spring centred to neutral, is moved by a double-acting fluid pressure or suction motor 29, both sides of the diaphragm being vented for neutral. In Fig. 8, one or other of a pair of friction bevels 146 on a shaft 145 driven continuously by the engine or an electric motor is selectively engaged electromagnetically with a friction bevel 143 driving the shift rail 25 through a screw-and-nut. For upshift, depression of a selector push button closes switch A to energize a solenoid 9 which moves a right-hand arm 8 to make a circuit which energizes the shift servos to move to neutral any shift rails 25 not already in neutral. The circuit also energizes the following solenoids:- 6 to cause a spring-returned pawl 5 to rotate the contact arm 1 one step clockwise, 41 and the left-hand 71 to energize the automatic throttle/clutch control of Fig. 3, 123 to tension a spring 122, a holding solenoid 137 for the core of the solenoid 123, 126 to hold a lever 121 carrying the brush 124 in the position shown against the action of spring 122, and, through the brush 124 and a contact 138, an upper holding solenoid 139 for the depressed arm 8. When all the rails 25 are at neutral, the solenoid 126 is de-energized and the spring 122 pivots the lever 121 to move the brush 124 to a contact 130. During the movement, the duration of which is controlled by an adjustable one-way air dashpot 140, the solenoids 71 are de-energized to give clutch engagement and throttle opening during the neutral phase of the shift. When contact 130 is reached, a second holding solenoid for the arm 8, and a right-hand solenoid 71 are energized, the latter completing the circuit to the arm 1 to energize the selected shift servo to engage the new gear ratio, upon the establishment of which all holding circuits are deenergized. Similarly for downshift, a second selector push-button is depressed to close the switch B in this case a vent in the dash-pot 140 being opened to allow a more rapid movement of the lever 121 and thus shorter clutch engagement and throttle opening during the neutral phase of the shift. To automatically insert intermediate ratios between the main gear ratios, using an overdrive whose lock-up clutch is controlled by a solenoid 20, a centrally pivoted contact strip 22 connected to the power supply is rotated manually from the position shown (Fig. 7) to contact a stud 23, preventing direct energization of the arms 8. When the switch A is closed, a spring contact 21 on the depressed arm 8 but insulated therefrom energizes a solenoid 16 to cause a pawl to rotate a triangular cam 18 through 60 degrees from the position shown so that it breaks contact with a right-hand blade 19 and contacts a second blade 19, to complete a circuit from the stud 23 energizing the solenoid 20. A further closure of the switch A will cause the cam 18 to step through another 60 degrees to re-engage the right-hand blade 19, deenergizing the solenoid 20 and completing a circuit t