Patent GB-408599-A (GB)
Title: Improvements in and relating to variable speed transmission gears
IPC: F16H61/02
Filed: 1932-10-07
Abstract: 408,599. Change-speed gearing. FLEISCHEL, G., Bleneau, Yonne, France. Oct. 7, 1932, No. 27977. Convention date, Oct. 8, 1931. [Class 80 (ii).] Comprises in change-speed gearing an arrangement of a friction clutch and a brake, or two friction clutches, in which when a middle member 7, Fig. 1, is moved left to engage a coacting member 9, a supplementary member 91 is moved oppositely to grip the member 9 on the other side, and when the middle member 7 is moved right to engage another member 11, a second supplementary member 11<1> is moved oppositely to grip the member 11 on the other side. In the epicyclic two-speed gear shown in Fig. 1, the coacting member 9 is a clutch disc rigid with a driving flywheel 16 which carries stepped planets 3 meshing with a sun 6<a> fast on a driven shaft 5 and with a sun 6b fast on a sleeve to which the middle member 7 is splined. The other coacting member 11 is a non-rotary brake disc rigid with a gear casing 15. The outer members 91, 11<1> are secured together by bolts 18 which slide through the member 7. In the position shown, springs 19 between the members 7 and 11<1> cause the members 7, 91 to be pulled together to grip the clutch disc 9 between them, so yielding a solid high-speed drive. When the springs 19 are overpowered by stronger springs 24, rings 22, 23 splined in the casing 15 are drawn together so as to engage and draw together the members 7, 11<1> which thus grip the brake disc 11 between them yielding low speed. The springs 24 are allowed to act to change down when a cam control ring 13 is turned so that pairs of bowls 21 carried by the splined rings 22, 23 drop into cam recesses 20 in the ring 13. Alternative means by which the outer members 9<1>, 11<1> are moved oppositely to the middle member 7 are indicated in Fig. 4. The middle member 7 carries bowls 37 which engage double-acting spring cams 41 carried by a ring 34 to which the outer grip members 9<1>, 11<1> are secured. The member 7 is moved positively as by a pullrod 14, Fig. 1, and as the bowls 37 ride over the cusps of the cams 41, the ring 34 is thrust rapidly in the opposite direction. Means for cushioning the change further is described with reference to Fig. 2, not shown. A hom carried by the control ring 13 moves between two dashpots the outlets of which are closed by valves operated from engine suction so that the gear change is delayed as a function of load. The invention is shown in Fig. 6 applied to two friction clutches in two-speed gearing of the countershaft type. This is a self-servoing device. The middle member 7 is a nut on a screw 44 slidably splined on the driven shaft 5 and the nut 44 carries rigidly outer clutch members 9<1>, 11<1>. A drum 49 has a feather-slot connection with a ring 7<1> feathered on the member 7. For direct drive, the springs 19 are allowed to act whereby the ring 7<1> and an outer member 9<2> grip a clutch ring 9. The nut 7 is then caused to turn on the screw 44 so as to effect a firm clutch grip on the disc 9. To change down, the control cam ring 13 is turned so as to allow the springs 24 to overpower the springs 19, whereupon the middle members are moved oppositely to the outer members and a gear 5<2> is clutched by its disc 11 to the shaft 5. An improved two-speed unit may be arranged in front of conventional or " snatch " changespeed gearing upon a vehicle whereby the usual main clutch may be dispensed with. In Fig. 7, 13 is the control cam ring of an improved unit, not shown, and 13<1> is a cam ring coupled to turn with the ring 13 and having a cam slot 54 for changing speed in the snatch unit shown on the right. When cam recesses A are in line with the bowls 21, both units are in low speed. With flats C under the bowls, the improved unit is in high speed, the snatch unit remaining in low. In the position shown, both units are in neutral. The cams are so arranged that when changing in the snatch unit, the improved unit is in neutral, so that all changes are without shock. In Fig. 8 is shown a vehicle transmission in which two control cam rings 13 of two improved units A, B and the cam ring 131 of a snatch unit C are geared to a common shaft 59 which is geared at 60 to a shaft 61 adapted for stepwise manual actuation in both directions of turning for gearing up and down respectively. Fast on the shaft 61 are two oppositely-toothed ratchets 67 adapted to be engaged altematively by a double-ended pawl 63 pivoted on a hand lever 62 which moves loosely between stops 621, 62<2>. By sliding a handle 65 the pawl 63 can be tilted so as to be operative for changing up or down at will. Two ways for operating the engine throttle lever 68 are described, closing for changing up and opening for changing down. Springs 72 allow this automatic action to be independent of the accelerator pedal 70. To open, to turn lever 68 to position o, a lever 74 is pulled by a cable 74<2> against a spring 74<1> with a dashpot 74<4>. To close, to turn to position f, a second lever 75 is pulled by a cable 75<2> against a spring with a dashpot. According to one way, the cables are connected to spring levers bearing on two cams 74<3>, 75<3> connected to the shaft 59 in such a way as each to be operative for its proper direction only of turning of that shaft. According to the other way, the cables are connected to the opposite ends of a tilt lever 83 pivoted on the hand lever 62 and adapted to be tilted in unison with the pawl 63. An arrangement is shown in Fig. 9 in which the pawl 63 can occupy two positions only, in engagement with one or other of the two opposed ratchets 67. The Specification as open to inspection under Sect. 91 comprises also a form according to the invention shown in Fig. 13 (Cancelled). The middle member 7 of a double clutch is coupled by links to the inner arms of levers 13<b> and the outer supplementary clutch members 9<1>, 11<1> coupled together by through bolts 18 are connected by links 13<c> to the outer arms of the same levers which are pivoted intermediately upon a disc 42 carried by the driving flywheel 16. Operation is effected through a rod 14<a>. The middle member 7 and the coupled outer members 9<1>, 11<1> are constrained directly by the levers 13<b> to move oppositely into gripping engagement alternatively with a clutch disc 9 fast on the driven shaft 5 and with a clutch disc 11 connected to the same shaft through a fixed reducing train 58. The clutching action is completed in each direction by a double-acting spring cam 40. Arrangements are described in which the oppositely-moving clutch members are formed as double-ended cones, and as doubly-coned rings of trough section. Alternative arrangements with simple expanding- boil clutches are described, one coil for each speed. A form of control lever is shown in Fig. 16<a> (Cancelled) adapted to replace the lever 62 of Fig. 8 in a case where one of the series change-speed gears comprises electromagnetic clutches. A tilt beam 87 is pivoted on the handle end of the lever 62 and is connected at its ends to the cables 74<2>, 75<2> for opening and closing the throttle during speed changing. This tilting is effected by striking down one or other of two knobs 74b, 75b on the lever which are geared together at 89 so that either may be turned to operate a suitable switch to change the coil-controlled clutches. Means are described for easing the friction clutches of a unit which is useful as in starting a vehicle. A pedal 83, Fig. 21 (Cancelled) is for this purpose mounted alongside the accelerator pedal 70 of Fig. 8. A double resilient connection is shown schematically at 84 between the speed-changing cam ring 13 and the manual lever 62 so that the former can be moved independently of the latter. Depression of the pedal 83 against a spring 88 causes lazy-tongs 86 to close on a pin 85 on an arm 14 on the cam 13 so as to move that cam towards neutral gear position. A chamber 102 connected to engine suction may be provided for easing the clutches automatically when the engine is running light. A variant is described in which the lazy-tongs 86 are replaced by a V-shaped cam which rises between guides and engages the pin 85 which is cammed into the bottom of the V. This easing of the clutches may also be effected by disabling a divided speed-control cam ring 13. In Fig. 23 (Cancelled) the cam 13 of Fig. 7 is divided into telescoping parts 13<m>, 13<n> normally held apart and up to their work by a cross lever 93 upon the pedal lever 83 and a spring 88. Depression of the pedal 83 against a stop 94 by foot or by suctionat 102 draws the parts of the cam together to effectual neutral. In Fig 25 (Cancelled) the work part 13 of the cam is separated by diametral section from the gear part 56 and these two are connected by a pinion 95 which normally turns on a pivot 97 linked to the pedal lever 83 and held fast by the spring 88. Depression of the pedal 83 at will swings the work cam 13 to neutral. This subject-matter does not appear in the Specification as accepted.