US1838096A - Automatic speed changer - Google Patents

Description

Dec. 29, 1931. G. FLElscHEL y 1,838,096

AUTOMATIC SPEED CHANGER Filed Maron 29, 195o 7 sheets-sheet' 1 @j W f E f ,w T 2 JD W5 B 51 e 'f' w0- V WAK/V221? V1 l l 27 3 A /J i i I W ,i A1 r wg I l l ,f 1 I 1 g l? t l l Y W' f v Q12/ 22/ l Dec. 29, 1931. G. FLElscHEL 1,838,096

AUTOMATIC SPEED CHANGER Filed March 29, 1930 'r sheets-sheet 2 Q Wfl/ru) 0k (1MM/wal Dec. 29, 1931. l l G. FLEISGHEI.

AUTOMATIC SPEED CHANGER A Filed March 29, 1930 '7 Sheets-Sheet 3 l l ZZ? 113 l I# a 28\16' l ,iwi Q. M

MIC/73% g Dec. 29, 1931. 5, FLElsCHEL 1,838,096

AUTOMATIC SPEED CHANGER l Filed March 29, 19550 7 Sheets-Sheet 4 l I l l zy. f Zig 29.

Dec. 29, 1931. cs. FLElscl-IEL 1,838,096

AUTOMATIC SPEED CHANGER Filed March 29, 1930 7 Sheets-Sheet 5 JJ! J3@ T234 Dec. 29, 1931. G. FLEISCHEL 1,838,096

AUTOMATIC SPEED CHANGER Filed March 29. 19250 7 Sheets-Sheet 6 @Na-M Dec. 29, 1931. G. FLElscHEL AUTOMATIC SPEED CHANGER Filed March 29, 1930 7 Sheets-Sheet 7 Patented Dec. 29, 1931 PATENT OFFICE GASTON FLEISCHEL, F BLENEAU, FRANCE AUTOMATIC SPEED CHANGER Application led March 29, 1930, Serial 110.540,020, and in Belgium March 28', 1929.

The present invention relates to automatic gear shifts for automobiles and the like.

One of the objects of the invention is to provide an `automatic gear shift controlled simultaneously by variations in motor load and by the speed 'of the driving or driven shaft.

Another object is to provide means operative by variations of the suction exerted by the motor to control an automatic gear shift.

An additional object is to provide means operative by a dynamo to control an automatic gear shift.

A further object is to provide means for correctingracing7 of the motor shaft during an automatic shift of gears.

Still further objects will appear in the course of the detailed .description now to be given with reference to the accompanying drawings in which Fig. l is a diagram illustrating the conditions of motor operation;

Fig. 2 is an elevation, partially in section, of one constructive embodiment ofthe invention in which a dynamometric and centrifugal ei'ect are utilized;

Fig. 3 is a diagram showing the operation of the gear shifting system;

Figs. 4 to 6 are two variants of the structure shown in Fig. 2;

Figs. 7, 8, 8, 81 show two different realizations of the .dilferential or olf-set device;

' Fig. 9 shows `the operating diagram of the geashift-differential device;

Figs. 10, 11, 12, 13 show four gear-shiftdiferential devices referring to diagram F ig. 9;

, Fig. 14 shows a gear-shift-dierential device utilizing centrifugal force and suction;

Fig. 15 shows a gearshift-differential device utilizing Water pressure from the circulating system and suction;

Figs. 16 and 17 show a realization and the Working diagram of a gear-shiftdier ential device utilizing the intensity of the current suppliedby a dynamo;

Figs. 18 to 30 relate to the devices to be added to gearshift-.diiferential devices;

Figs. 18 to 25 show the methods of putting ferent systems;

into action the decisions of the gear-shift-differential device;

Figs. 18, 19 and 20 show the adaptation of these methods to three gear-boxes of dif- Fig. 21 shows the means of utilizing for the control of these methods, the engine starter;

Figs. 22 and 23 show the means of combining the methods of execution and the power selected for this execution;

Figs. 24 and 25 show respectively in end elevation (with sections) and plan view of the means of. control to be substituted for thegpresent means of control which are not automatic;

Figs. 26, 27 and 28 relate to three different methods of realization of synchronizers, F ig'. 29 being a variant of a detail of Fig. 27;

Fig. 30 shows, in perspective, an operative assembly including the specific devices represented in Figures 11, 15, and 20.

It is proposed in the'rst instance to study the case of gear-boxes with distinct combinations, or that of progressive gear-boxes in which one selects a certain number of ratios, as near to one another as may be wished, but Which will be used to the exclusion of all others, such ratios being assumed as corresponding to the combinations of the first men- 80 tioned gear-boxes.

Fig. 1 shows the characteristic lines OD and OE, of two consecutive combinations which We will call respectively the higher combination and the lower combination, in a gearboX containing an indeterminate number of combinations. The speeds o of the motor or driving shaft are shown in abscissa and the speeds w of the driven shaft as ordinates. the latter being proportionate to those of the vehicle. The minima and maxima speeds between which power can normally be utilized have been denominated a2 and b1 respectively.

It is desired, starting from the lower combination to change up to the higher combination at a vehicle speed corresponding to speed fw of the driven shaft-after which change the engine will be revolving at speed v2 one sees that this change must only be made the o eration.

when the engine is turning on the lower combination at a greaterspeedV1 defined, as resulting from V2, by the ratio of the two speeds considered which is 'represented on Fig 1 by The interval between these two driving speeds is hereinafter denominated the differential resistance and increases with w". eration causes a drop in the driving speed from 'v1 to 'v2 (resulting differential resistance) whilst the speed of the driven shaft remains practically constant and equal to lwo for if the operation has been properly effected the vehicle has maintained the same speed.

If at the same vehicle speed lwO it is .desired to change downto the lower combination, the higher must be dropped at engine speed c2 and the latter shows a speed 'v1 after Therefore, for a given vehicle spee wo, whichever way the operation is performed the two driving speeds v1 and o2 will always correspond on the two consecutive combinations; they will hereinafter be denominated corresponding change speeds. In Fig. l the operation is represented in both directions by a practically horizontal vector v1 v2 whose ordinate corresponds towo and the v1 v2 direction of which defines thef changes up and in the other direction-of the changes down.

Therefore if one adopts as a-basis the speed of the driven shaft or of the vehiclewhich will hereinafter be coupled under the designation fw-, one finds three zones in which the functioning differs totallly. In zone Q02 w3, whatever the external conditions may be, speed changes are impossible and the lower combination is compulsory since a change would bring the engine, in a higher combination, to a speed which it cannot attain. In zone w3 lw, one can have a lower or higher combination, it is the zone of possible change. In zone 105 lw6 whatever the external conditions, speed changes will be impossible and onek must necessarily be in the higher combination for the same reason that the speed of the engine is impossible with the lower combination In order to determine the speed at which one should make the change in the zone of possible change, one can adopt any rule laid down by practice for instance and as will 'be assumed henceforward, set up as a principle that the change should 'take place at a higher speed according as the load on the engine is greater; and whatever rule may be adopted, the driver may beallowed, if needs be, to use his own discretion in the intermediary zone and modify the said rule.

Starting from this principle when the 'torque demanded of the engine is small the speed change occurs along horizontal A1 A2, determined by the lower limit a which cor- The op-` tude, the speed change should take place aclc'ording to horizontal B1 B2 determined by the upper limit b1 corresponding to speed Iw of the vehicle. And if in zone ws w, the

variations in the variations of the speedl change fw were in strict proportion to those of the load', 'under half load ofthe engine for instance one would change half way between w3 '1115. Yet, .if it is' impossible to change speed below lw8 or above w, in normal practiceon the open road, one may allow the driver to adapt the possible change zone to special incidentalcondition's such as going through-a town or descending a hill, the engine then retarding the car which, in practice, is equivalent to displacingl the zones. p

l`The gearilever must there obey thethree zone law completed by the principle mentioned above, if one bases on the speeds w of the driven shaft. Y

If one bases on the speeds v of the driving v where this combination remains compulsory,

then the zone of possible changes b2 a2 part of which overlaps zone a? a2 where the lower combination is compulsory.

By analogy with the driven shaft one can i determine by calculationptalging into account the characteristics of the gear box and the conditions of its realization, an intermediary value om to define a speed change o1 'v2 or c2 lv1 providing that, starting from this speed fv, onecan always, by completing the gear lever by adding to ita device called difl'erential described hereinafter, re-establish the true value of lv1 at which speed change must be effected in changes up and the true value 'v2 for changes down. In this case fictitious speeds such as vm designate three zones, as in `the case of the driven shaft, zone a2 fu in which the lower combination is compulsory, zone fv o in which one must change over at a speed greater in proportion as the load is greater, and zone 'vp b1 for which the larger combination is compulsory. All such fictitious speeds, correspond to points such as om and are grou ed on -a straight line OT midway between E and OD. The three zone law therefore applies 'also to fictitious s eeds v taken on the driving shaft which ma es it possible to utilize the same realizations as in the cases of speed w, providing one has recourse to a differential which transforms these fictitious speeds into a real driving power such as al in the case of changes down and v2 in the cases of change up.

lIf the speed is taken on the driven shaft, passage between two consecutive combinations is defined by a single speed wo of that shaft whereas if the speed is taken. on the driving shaft the same passage is defined by the two corresponding change speeds 'v1 and v2 or by the fictitious value om and in both cases the operation can be effected in either direction.

The three zone law can with advantage be made to control progressively variable gear boxes for the following reasons:

The maximum speed b1 lof the engine (Fig. 1) generally produces a torque smaller than the normal torque obtained say at speed b2 corresponding to L05 (C1 Fig. 3). It is therefore logical not to change down before the engine has slowed up to speed b2. rlhis will be -the zone of maximum favorable ratio and,

by analogy with what precedes, is also denom` inated the zone of compulsory high combination. It is logical also not to increase the demand on the engine, through an increase inl gearing, until a speed a1 higher than speed a2 which corresponds to the extreme ldling of the englne. In such a case a1 can be considered, in practice, as the equivalent to b2.-

boxes provides more favorable performance.

The above makes it easier to understand the functioning of the different mechanisms which will be dealt with hereinafter.

. bination, or increase the gearing, whereas when the load increases it causes one change down to the lower combination or reduce the gearing.' These two expressions will be considered as synonymous hereinafter The gear shift is actuated by the effects of the determining causes-speed and loadcompleted in case of need by secondary effects. All these effects are produced by forces or actions created through any phenome? on or phenomena function of these determining or accessory causes. The gear shift acts on a tell-tale on which is concentrated the resultant of all the actions proportioned and directed in 'such a way as to observe the three zone law and under the impulse of this resultant the tell-tale can take up at least two characteristic positions, one in which it actuates a change to the lower combination, and the other to the higher combination.

Figs. 2 to 17 show different examples of gear shifts each one including differentials, except that shown in Fig. 2 of their working diagrams '-(F igs. 3, 9 and 17).

Figs. 2 to 6 show gear shifts in which the load action is recorded on a transmission dynamometer and the speed action is centrifugal' force acting on two eccentric weights which are either (Fig. 2) placed on the driven shaft and do not in consequence require a differential gear or else (Figs. 4 to 6) fitted to the drive shaft which makes a dierential necessary owing tothe resulting differential effect affecting the driving speeds at the moment of changing.

On control 15, in a gear box 1,.-With say two combinatlons, a lever has been` fitted and acts as a tell tale. It is actuated by the actions by means of rod l() which is also fitted with an antagonistic spring 11 the use of which will become evident in the explanation of the diagram Fig. 3. I

The actions selected have a tendency, one (speed) to increase the gearing, and the other (load) to reduce it, and act contrariwise on rod 10, the load of spring 11 adding itself to the load action. f

In Fig. 2, the effect of the centrifugal force of weights 5, hinged at 6 on part 7, coupled on driven shaft 3, is collected by a slidin sleeve 4 and transmitted to rod .10 by for 9 engaging slot 8 of the said sleeve.

The dynamometric effect is collected by fork 12 which is solid with rod 10 on sleeve 13 which can slide on a long key on drive shaft 2 and is machined in the form of a nutu with a very large pitch to engage with a corresponding screw thread on drive shaft 2. The driving torque, while it causes shaft 21 to revolve, also develops a longitudinal reaction in sleeve 13 which is constantly in proportion to the momentary value of the torque.

ln Fig. 4, the two actions are taken from 'drive shaft 2 so that the two sleeves and their interconnection can be vcombined in one piece 13 and spring 11 tted direct on shaft 21 resultant of these two 'actions which they transmit, by means of rollers 21, to the suitably inclined ramps of part 131, which is coupled to' sleeve 13 on which spring 11 acts and which is connected to control 15.

Setting aside the question of the point whence the speedis taken,the working ofthese various gear shifts is evidenced in/diagram Fig. Son which speeds w, assumed as taken from driven shaft 3, are shown as abscissae and the different positions of A as ordinates.

If the centrifugal force of the two masses were considered separately it would be rep resented by a parabola, such that P, the summit of which would be at 'the origin O but as the check spring acts contrarily, with its force OF, to the action of speed its effect brings the summit of parabola P to point F below axis ow.

f The load action-.proportionate to the driving torque of the engine-which varies according to the speed and the degree of throttle-opening given to the engine, for instance with the opening of thelcarburetor-- is represented for a given admission, by `a curve the ordinates of which are in proportion with those of the-curve of the driving torque for the same admission.v v

Hence, at full throttle opening, the load action is represented by a curve such as C1 and with partly open throttle by a curve such as C2.

In order vto`obse`rve the three zone law the forces are apportioned as follows. Check spring 11 has a value .OF determined so that parabolaP may intersect axis ow exactly at the speed w3 belowgwhch lowspeed is imperative.

Th relation of the proportion of the load action of the driving torque is selected so that the charge action C1, at fullthrottle, meets parabola -P precisely at the speed Iw5 above which the higher speed is imperative.

, Below w3 spring 11 still exerts an effort greater than the speed action, so that the resultant is in the direction of the action of spring 11 and that tell-tale lever 14 compels control to take up the position of small combination above w5 the ordinates of parabola P being always greater than those of curve C1, the resultant is inpthe direction of the action of speed, even-with maximum load action. .x Tell-tale lever 14 therefore compels controlV organ 15 to take up the larger combi-l nation position. And'` between w3 and-11:5 the resultant depends on the degree of admission given to the engine which determines curve C2 correspondent with the momentaryutilization. .So long as the speed doesV not reach w (junction ofP and C2) the speedaction beinglower than the load action, the result- ,ant will be in thedirection of the load and willv placethe control organ 15in the small combination position. Below 'wo :the speed action becoming greater than the load action the resultant will be in the direction of speed and will place the control organ in the large combination position. If there is a variation in speed -it is at the moment when it attains value lw0 that the change of combination occurs.

The diagram shows that'the more curve C2 approaches maximum curve C1, the more speed wo approaches w. On the contrary the .more curve C2 approaches Ow, the morenspeed The action of the speed lever may be based on phenomena otherthan centrifugal force for the speed or than dynamometrip action for the load providing the phenomena utilize are perfectly defined in respect of speed and load. The phenomenon utilized may be a combination and itself influenced at the same time both by speed and load, such as the depression which exists in the inlet manifold of theinternal combustion engine to which the mechanism is attached .(Figs. 9 to 13).

On examining 'the phenomenon it proves tol be determined by two variables, 'the speed o of the engine on the one hand and on the other hand vthe section of the carburetor gas inlet which is controlled by the throttle. If one records the diagram which represents the depression (Fig. 9) function of the engine speed with the throttle full o en, one obtains a curve of parabolic nature 5 ip which the depression depends solely on the engine speed, for any lesser opening, considered sep'- arately, there will be enother similar curve, such as G, these curves being spread between G5 and G1 corresponding respectively to max- 'imum andminimum opening. The greater or less throttle opening of the carburetor operated by the driver, in the same way as the regulating apparatus for any motor, determines the load of the engine so that, on an intermediary curve G, for any point of` H at a Speedo, one can separate the causes and submit that since depression oh k dependsvsolely on the speed, its action may be materialized, and the supplementary depression h'H which depends only on the load canact inthe same way for the load.

It is to be noted however that this supple,--

menta-ry depression varies v,inversely to the load for, given a constant speed of the engine o, it increases as the carburetor is closed down that is toY sav when the load diminishes passing at H2 on a; higher curve G2.

Hence a peculiar dispositionl of the diagram according to whichthe actions should aggregate.

In order to regulate the action 'of the antagonistic spring "11 one A proci'zeds along the possibley passage b1 b2, the intersection of ordinate op with curve .Gr5 indicates the value OI which mustfbe given to the antagonistic spring 11 which must check th-e act-ion of depression. And lon any intermediary curve G the change lever will cause the combination to change at a speed um which corresponds to the intersection of curve G compared with the horizontal (value of sprinoF l1). In the same way fu is the release speed with the smallest opening .of the carburetor on curve G1.

The three zone law is therefore observed in respect ofthe fictitious engine speeds, such as defined by line OT in Fig. 1. If one considers depression curve G5, corresponding to the greatest gas admission, above fictitious speed o", at which this curve meets horizontal I, representing tension of spring 11, the depression overcomes the spring and the resultant in the direction of depression sets device 15 in the position corresponding to the high combination. Curve G1 corresponding to the smallest admission meets horizontal I at a speed o below which spring 11 being stronger than depression, the resultant acts in the direction of the spring and the small combination becomes compulsory owing to the position taken up by control device 15.

is that of-the possible changes, the changeb of combination therefore ocurs at a speed fv which increases as the load becomes greater. Figs. 10 to 12 show various realizations utilizingT depression without modification.`

The latter acts in a chamber 31 on a moving or pliable organ such as piston 29 or diaphragm 29]L and the action is taken up by rod 10 on which antagonistic spring 11 acts, and which transmits the resultant to tell-tale lever 14 and to the control device l5.

Fig. 13, shows an arrangement whereby it is possible to produce, if so desired, a modification in the relative importance of the speed and depression load effects. thus per'- mitting suitable apportioning. Depression acting on capacity 3l is transmitted, unmodified. to lever 95a working on a fiXed point 951. T hisl lever transmits the depression action by a roller 9T to another lever 9?L working about a fixed pointL 961a inversely to the former and this lever 96 is connected to rod 10, bearing spring 11 and acting on control device 15.

Roller 97 does not modify the action of suction when it is in line with rod 10. When it moves away from articulation 951 Of lever 95, it diminishes this action and inversely it increasesit when it approaches the said articulation. Y

The movement of the roller is controlled by the resultant of another action of suction, acting in-a capacity 31a on a diaphragm 29a, against a spring 42 in such a way that when suction overcomes spring 42 in this additional device, roller 97 moves so as to reduce the main action of suction or increase it by moving in the opposite direction. A

It would be possible to suppress the eX- tra capacity 31 and to utilize a portion of the action of main capacity 31 by means of a lever on which spring 42 would act. The displacement of roller 97 could also be connected with that of the accelerator pedal.

This method makes itI possible to apportion, in the complex phenomenon of suction the eifects due to speed compared to those d'ue to load forsuction, for, used without modification it can, for certain engines, be /far more sensitive to the variations in throttle opening than to speed variations which occasion an excessive value in the load action with regard to the speed action. This makes it possible to utilize the suction as a load action in replacement of the dynamometer in Figs. 2 to 6 providing one takes into account the components of the speed action which it includes together with the principal speed action which would be utilized.

Fig. 14 shows a realization in which the principal speed action is obtained by centrifugal weights 5, fitted to driven shaft 3, and connected through rod 10- to tell-tale lever 14 and to the control device 15, and on the other hand to diaphragm 291 which is subject to the action of the suction in capacity 31. This suction supplies the full load action and part of the speed action which comes in addition to that of weights 5. The action remains the same as that of diaphragm Fig. 9, but curve G5, whiehis still a parabola, is obtained by the additition of the ordinates of the two partial speed actions mentioned above. In this case it is possible to suitably apportion the total speed action with regard to the load action by determining in consequence the effect of weights 5.

For this example it has been assumed that boX 1 includes a certainy number of distinct combinations, say four, and that control device 15 can assume a characteristic position corresponding to the engagement of each of these combinations. the load of the antagonistic spring is suitably determined for each change and if it is noticed that for any one of these changes the speed of shaft 3, consequently the speed action of the Weights, becomes greater as the changes are made on combinations ofk higher denomination it becomes necessary to have In this case,

an antagonistic sprin of a certain value for the change from first' to second combination, another giving a greater load for the change from second to third etc. This can conveniently be realized for instance by -placing in opposition-to fork 9` springs 111 112 113V positioned in eclielonfby checks 80 so that in the positions which the fork occupies Aduring a change from rst to second combination it can only be solicited by spring 111 and touch spring 112 only when engagement with the` second combination has been completed.

In this way a change from second to third combination is effected against the combined load of.two springs 111 and 112, load of spring 112 being determined by the increase in speed ,action due to the increase in speed of shaft 3 caused by the change of combination. The action of spring 113 is determined in the same way and so on.

Fig. 15 shows a device in which the main speed action is produced by the pressure in the cooling jacket of' a cylinder tted with water circulating pump 39.

The load action with a secondary speed action is produced in a capacity 31 on which the carburetor depression acts.

If the main speed action due to water pressure is received by a diaphragm 40 in the same direction due to the complex action of depression actin on two diaphragms 291 292 of unequal sur ace one obtains the same functioning as that described in connection with the diaphragm of Fig. 9 in Whichthe parabola G54 would 'be obtained by the concurrence of the ordinates of the parabola corresponding to the secondary speed action of depression and of the parabola representing the water pressure variation resulting from`engine speed and consequently that of circulating pump 39'.

The apportioning is eil'ected in this `case by determining the suitable dimensions of the various diaphragms 291 292 and 40. It

is preferable that diaphragm 40 should be subject only to the dynamicpressure due to. 'speed and that static pressure which may occur for instance owing to vthe difference in level which may exist between the radiator and diaphragm 40 should be counterbalanced. One establishes diaphragm 40 between twoA capacities 361 and 362. Capacity 362 is connected by aductv392 for instance to the intake of the pipe where there is only sta'ticpressure while capacity 361 is connected by duct 391 to the output of the pump which is under total pressure, both static and dynamic. One surface of the diaphragm therefore receives total pressure and the other static pressure so that the diaphragm is solicited only by thevdiierence' of these pressures, that is to say to of static pressure in capacityy 361 might be replacedby a sprin of equivalent load.

One might also, ugs. 15 and 16, establish a change speed for two or for a greater number of combinations by having recourse to the electric current supplied by a generator for speed actionand for load action, the variation in this current resulting from the effect of a resistance in the circuitthe value of which would be controlled by the movement of the accelerator pedal either direct as shown or through depression, by having recourse for example to the auxiliary device which causes the displacement of roller 97 o'n Fig. 13.

It has been assumed, in example Fig. 16, that one utilized dynamo 45 .of an engine, feeding a circuit comprising a battery of accumulators 451.

An electric coil 46 is mounted vin series in Vthe electric lighting installation (which is not shown) and received current supplied by dynamo 45. This supply is a function of the speed at which the dynamo turns, assuming that the terminal tension of the battery remains constant. This coil 46 surrounds a soit iron core 47, lixed on rod 10 which bears antagonistic spring 11 and which is connected to tell-tale lever 14 and control device 15. Spring 11 tends to withdraw core 47 from coil 46 with the intensity of the current it receives. Accelerator pedal 48 is connected with sector 49 by a resistance 5() inserted in the energizing circuitof dynamo 45 which produces the load action.

Diagram Fig. 17 shows the working of this arrangement; engine speed fu of the engine is shown is abscissae and attractive force f of coil 46, proportionate to the current produced, as ordinate. If one ceases to act on pedal 48, i. e. if one throttles down to a minimum, resistance 50 does not enter into play.

The intensity of the current is not reduced and causes an attractive force in coil 46 corresponding with curve G1.

If the throttle is wide open resistance 50 enters into play in full and the current circulating 'in the circuit is reduced and in consequence the attracting :torcev of coil 46 this force corresponding to G. diary position of the sector the re resentav tive curve of the attraction forcee the coil corresponds with G.

The proportioning of the'actions is e'ected as follows Curve G1 which corresponds to the utilization of dynamo 45 without resistance, determines, by its intersection with the ordin ate cf speed lu, above which the small combi nation iscompulsor the value OI of antagonistic spring 11. alue of resistance 50 is determined so that curve G-Which represents the working of the dynamo under full resistancc, passes through the meeting point of the ordinate'of speedl '0 (above which'the higher combmation is com ulsory), with horizontal dynamic pressure. In many cases the effect I. For an interme 'ary resistance, i. e. for an For an intermeintermediary position of the accelerator and consequently an intermediary load of the engine, the functioning of the dynamo,'will correspond to an intermediary curveG the intersection of which with the horizontal will determine speed 'vm at which the change of combination occurs. The nearer curve G approaches G5 which is full en 'ne load, the nearer speed 11' gets to cp. Tlllchange thereforeoccurs at a speed which 's higher as the load becomes higher. Thisis in accordance with the three zone law`and with its complementary principle;

In the foregoing, the place where speed was taken has not been taken into consideration.

If the speed is taken on driven shaft 3, between gear-box l and the road wheels, the change will be effected without any modiication at an indefinite speed fw" the momentary speed of the shaft as set forth in connection with Fig. 1. The gear-shift devices described can therefore be applied without any other addition. If the speed is taken on shaft 2 of the engine or any other-shaft connected with it, the change up after'which it is desired to obtain speed e2 should not be effected as explained in connection with Fig. 1, at a speed om for which the gear shift has been set. It is ,necessary to accelerate the lengine previously up to a greater speed Q11 (safety dierential effect) and the operation of changing, commenced at c1 brings the speed of the engine to c2 (resultant differential action).

The differential mechanism working in connection with the gear shift which left to itself would effect the change at the intermediary speed om fills a double function; 1 to cause the change to occur at speed 111 if the change is upward and 'v2 if .it is downward for, once the operation has been effected one finds the desired speed v2 or '211; 2 to suppress the disturbancesl which sometimes in the `case of the speed action, sometimes of the load action, result from this displacement from vm to v1 or lv2 (safety differential effect) then o'f 'v1 to 'U2 or from v2 to '01, (dierential effect due to the change).

'Ihe double action of the differential device may be obtained by placing on tell-tale lever 14 or on one of the parts connected with it a resistance which will oppose its movement in any direction, up to a suitably determined value of the actions.

' This resistance necessitates supplementary effort on the part of the resultant'actingon the tell-tale lever before `it canl cause it to move, and according to the direction of this resultant the real speeds of change over are off set on either one or the other Side of fictitious speed vm at which the change in position of tell-tale lever would have occurred had the differential device not intervened; and the action of the differential device can be calculate-d so that these off-set speeds may reach or exceed .'01 and '02.

This can be effected either by utilizing an p auxiliary power which may b e distinct from the actions, or it may be drawn from those actions and acting on a sort of bolting device or brake of which this force limits the eect or else by causing the perturbed action or actions lto act on the rest of the mechanism through a connection in which, by a'variation in the length of the leverage the undisturbed actions are amplified or reduced in the same proportion as the disturbed actions so that their relative value may become what it was before the disturbance.

Fig'. 12,shows a realization of this sortin which the bolting is obtained by a projection 17 with two opposed ramps borne by a part 16 solid with rod 10on which the actions work. A ball 18, loaded by spring 30 which has a constant but adjustable tension, resists the displacement of rod 10 to an extent f which depends on the tension of the spring and the slope of the ramps. y This resistance v can therefore be set to correspond to the greatestdisturbances the differential eect causes to the actions. As this ball is only in a stable position at the foot of either of the ramps, this olf-set device only permits two characteristic positions of the tell-tale lever and is therefore suitable for a two speed gearbox, the engagement of each of the combinations being obtained when tell tale lever 14 occupies the corresponding -characteristic position.

Fig. 14 shows a similar arrangement fitted to a four speed gear box. It is sufiicient to provide three cams l17 on part 16 arranged so that the ball drops in the hollow between two cams'.

The actual Aolf-set thus obtained is only equal to the theoretical off-,set at its highest value. In other circumstances it exceeds it.

If it were desired to realize off-sets exactly equal to the theoretical at all speeds one studies more especially the corresponding solution. If one desires for instance an olf-setting device for the speed effect taken off the engine, calculation shows that the auxiliary power exerted on the bolting device must be produced bythe same influences as the speed action and remain in a suitably calculated proportion to it when variations occur in this influence. A theoretical bolting device of this sort can be obtained for instance by the means shown on Figs. 4 to 7.

On Fig. 4 thev off-setting device is constituted by cams 17, turning with the Weights and auxiliary weights 18 sliding freely in recesses provided in sleeve 13, so as to turn with it at the same speedv as weights. These auxiliary weights .'18 fulfil the object of ball 18 weights 18 replaces spring 30. In this manner, insteadofthe bolting eiiect being con-v trolled by an .auxiliary force which is always 'in exact proportion to the speed action.

On Figs. -5 and 6 bolting is also ensured by an auxiliary force in proportion with the speed actionbut it is obtained from the weights themselves which supply the speed action and the mass of which has been determined to assume this double rle. Ramps 17 and 118 the object of which was explained in Fig. 4 are placed at the point of contact of driving arm 20 and weights 5.

i* When vweights .5 move towards, or away from, the center of the rotating whole, cams 18 must respectively clear corresponding cams 17"of arm 20. Fig. 5 shows cams 18 at the moment ofclearing. if the effort de manded by this operation is properly calculated everything happens as correctly as in the example shown on Fig. 4r part of weights 5 suitably determined acting as auxiliary weights 16. l

Irrespective of the speed action utilized one could realize bolting vproportionate to this action and produced by it. Fig. 7 shows agdisposition of 'this sort. 'One usesythe action of speed amplified so as to be able to also supply the auxillary force of the differential device on rod 22 which distributes it lthrough rocking lever 221 in the suitable proportion determined by the' leverage ofthe said rocking lever, on the'one hand to rod 10 on which other actions act (load and antagonistic spring 11) and on the other through a bellcrank 23 on ball 18. A spring 30 can be inserted between the bell-crank 29 and ball 18. Up to the priesent we have seen gear-shift differential devices which cause the tell-tale lever to assume as many characteristic-.positions as-there are combinations in box 1.

It may be advantageous to reduce toa minimum the characteristic positions which the tell-tale lever can occupy to control the diii'erent combinations whatever theiry number.

Thus for gear. boxes including more than two combinations and Ain which the control device can voccupy more than twouseul positions one can withinthe limits of invention have recourse to a lever which, in an active position, causesthe changes up vin combinations, or the changing ofthe higher combination to another active position the drop in combinations and, in a neutral position determines the -utilization ofl the combirlation already engaged.v The method of attaining this result will be hereinafter described. If

this disposition is alluded to here, it issolely because of the simplification it permits in the design of the differential device by suppressing a number, which may be large, of the characteristic positions of the differential de vice and thanks to this arrangement adif ferential device designed to control a 'two combination gear box is suitable for a gear box containing any. number of combinations.

Fig. 7 shows a realization of this disposition where the bolting ramps are recesses 171 instead of projections co-operating with ball 18. Assuming the engine to be revolving at fictitious speed om, the resultant of the actions is null and ball 18 is at the bottom of the recess. If the engine speeds up to v1 or slows down to v2 the bolting effect is such that it is higher than the resultant which occurs in either direction and it is only when engine `speed hasl got some way beyond U1 if accelerating and u2 if decelerating that the resultant will be able to overcome the bolting resistance placin tell-tale lever either in the up or the down c ange position.

rlhe change of combination then occurs in the suitable direction but the resultant diiier-Y ice i gear-shifts and those mentioned last neutral-position-gear-shifts and any gear shift of the former type can be converted into one 0f the latter 'type by modifying its bolting ram s.

Fig. 8, 8a and 8b show another realization of the differential device where, instead of introducing an auxiliary bolting force, one conciliates the correct functioning of the actions with the diiierential `effects by varying the leverages.

The principle consists in transmitting the action, distributed by a speed change, by means of a lever such that at the moment of the cha-ngel the evera'ge varies making the new values of the actions o-n the new ulcrum, equal. to the previous values measured on the primitive fulcrum.

-Referring to the disposition in Fig. 2, but' vice will be realized by interposing-between the speed action which has been disturbed (acting `on fork 9) and rod 10 which connects it to the undisturbed actions (load and antagonistic spring) and to tell-tale lever 14, a iat tappet 24 which in medium position of fork 9, makes contact with two rollers 251 and lll" 252 borne by lever 26 hinged at fixed point 27 and 1connected by rods 28 to rod 10.

Assuming lever 14 has a tendency to take up the position of a higher combination, this movement causes an angular displacement of lever 26, roller 251 ceases to be in contact with tappet 24 (Fig. 811) and the speed action can only act through the short lever arm m1 whilst the other actions retain their lever arm 'ntr1`he speed action must therefore become sufcient to compensate these conditions and the speed must therefore increase further above fum which would .have been the change speed if the lever arms had been equal so that lever 14 might actually occupy its operative change up position. One can select the lever arms m1 and m2 so that the new speed necessary may be equal to '01.

Y nation.

.to o2.

Supposing` now that lever 14 tends to occupy position operative for a drop in combi- It will tend to bring'rod 10 towards the left of Fig. 8, until roller 251 makes contact with tappet 24. Up till that `momentthe load action and antagonistic spring 11 acted onleverm2 to overcome arspeed which had only lever arm m1 (Fig. 811). But at this moment the speed action on lever arm m3 is greater than m2 (Fig. 8a) and for the movement to continue, to reach the active position of changing down, the speed must diminish further. One can set m2 and m1 so that the new speed at which the lowercombination will be engaged will, at most, be equal Fig. 10 shows how, in the case of suction, one can realize a bolting device` the effect of which will always be in proportion to this suction. For this purpose an auxiliary moving organ 32 is submitted to this suction and presents an action determined by the lmportance the bolting eort must assume in relation to the principal action of suction. rlhis organ' 32 acts on suitable bolting ramps 17 and 18.

Fig. 11 shows how one can draw abolting effect in proportion with the principal suction action on organ 29 which receives the` suction action by means of bell-crank lever arms 33 and"34 whichare determined according to the bolting efect desired. The ramps on one of the two bolting pieces can be replaced by roller 172. If it is desired that the proportionate bolting effect should be limited to a certain value one can make the ramps 18 ona part 35 hinged to a fixed point and pressed against roller 172 by a spring 351 of suitabl-e tension. Immediately the bolting effort exceeds the limit set determined components of the gear-shift on the one hand and on the other the bell-crank 33-34 which acts on bolting device 171-18 through distance spring 351.

Fig. 15 shows a differential device similar to that on Figs. 8, 8a and 8b, arranged in such a way that the driver may adapt the change zones to special conditions such as the passing of a cross-road or the descent of an incline, the engine retarding the vehicle by displacing the change speeds zones. He can effect this by control lever 44 which displaces a roller 43 between the planes provided` respectively on tell-tale lever 14 and on lever 241 as has already been explained with a view to another object in connection with Fig. 13. The displacement of this roller temporarily modifies the value of antagonistic spring 11 in the desired direction which results in .I

checks 441 and 442 act as limits to the inter- I vention of the driver.

On Figs. 15 and 16 it has been assumed that the tell-tale lever may give an indication to the driver of its active positions by actuating, by means of a contact, a signal such as lamp 51 when in the position of an upward change and by Contact 382, a signal' 52 when it is in position for a downward change. In the neutral position there is no signal.

The arrangements described above, as examples, are some of the means suitable for executing the decisions of the gear shift in gear boxes of various systems. The gearboxes most adopted can be placed in two classes: 1, systems in which the engagement of each combination is effected by a resilient coupling, clutch or brake; they are, for instance planetary gear boxes in which each speed combination incorporates a clutch or a progressive brake; 2, those in which theengagement is by sliding pinions or dogs-usually completed by an external progressive clutch.

In all cases one has recourse for the operations necessary to carry out the execution of the decisions of gear shift /-which replace all the operations a driver would efect--toV ener which may be quite distinct from that applied to the gear shift and which will hereinafter be known as outside energy. The power can, for instance, be supplied by the engine, the electric generator, a reserve of air compressed by the motor, etc, This energy acts, when necessary and in the roper 'di- 'rectionon controlorgan 15, contro led by the gear shift.

'In case of need this control organ can be arranged so as to ensure the execution, in their proper order, of the secondary manuvres (other than .those which up to the present were effected by the driver through the gear leverto change gears or start the vehicle).

sriY

The whole can well be completed by safety devices on the one hand (synchronizer, automatic clutch for starting) and on the other hand by organs of convenience, reducing the drivers intervention to a minimum for such manuvres as must be left to his discretion such as forward speed, stopping and reversg Figs. 18 to 25 and part o Fig. 30 show different dispositions of org n 15 of gear-boxes based on different principles, Figs. 18 and 19 refer more particularly to boxes fitted with progressive engagement for each of their combinations and Figs. 20 to 25 to snatch boxes such as those employing gear wheels or dogs.

Fig. 18 shows the control of a three speed gear box arranged to function under the rect influence of an outside agency. This 20 may be supplied by any outside source of electricity controlled by the positions of lever 14 which can take up a number of posi-l tions (Fig. 14) bringing into action, in the case under consideration one orother of three electro-magnets 531, 532, l533, 'which act respectively on the three combinations 541, 542 and 543 of an ordinary planetary gear type. Lever 14 connected to the current can contact with either lof three contacts 551, 552

30 and 553 corresponding respectively to the positions of lever 14 which engage first, second and third speeds. It is obvious that the same arrangement could beA used With a lever 14 having a neutral position (Figs. 7, 8, 13, 15

and 16) by introducing between the said lever and the organ cooperating with contacts 551 etc., a suitable movement transformer ensuring the distribution of current tc the contacts.

the different clutches respectively by- levers 571, 572, 578 and 571 controlled respectively by cams 581, 582, 588 and 581 fixed to? a shaft which acts in the same way as control device 15, in su'ch positions that owing to their shape there can only be one clutch tightened at a i time and that the clutches tighten progressively in the numerical order of the combinations. Rotation of shaft 15 in one direction corresponds with upward combinations in numerical order and in the other direction to downward combinations. In the case of four combinations one arranges that the engagement of one combination in regard to the next shall take place when shaft 15 has G0 made one quarter turn. The mechanisms ensuring the rotation of shaft 15 in the desired direction and to the correct angle will be described below.

The disposition (F ig. 19) might be adapted L for the control of a gear-box such as shown respectively fourth speed.

in Fig; 18. It would be sufficient to place on shaft 15 a distributor Contact placing 'itself successively opposite contacts such as 551, 552

`and 553 (Fig. 18) through the rotation of 'shaft 15. The-re are planetary boxes of the that shown on Fig. 19 for clutches such as Fig. 20 refers to the case of snatch gear boxes and shows a four combination gear-box actuated respectively by sliding gears 591, 592 and 593 for first second and third speed and by a dog clutch for the lThe slidinggears and dog clutch are controlled by cams 58a and 58b fixed to shaft 15, theoperation of the said cams and shaft being similar to those of the example set forth in Fig. 19. p v

In snatch gear-boxes one must interpose the general clutch 60 of the vehicle to enable the displacement of the sliding gears. This result is obtained automatically through the intermediary of cam 61 fixed to shaft 15 and Such that at the latching positions of shaft 15 corresponding with the operation of any one of the combinations, clutch 60 is tight and on the contrary released through the control of lever 62 during the rotation of the shaft when it passes to the next upward or downward combination. A quarter rotation of shaft 15 therefore ensures the operations a driver would effect.

Shaft 15, in the operations it controls through the cam, is subject to highly varying resistances during its travel; it has t-o produce an important effort in particular when it causes the declutching of the main clutch whilst the clutch-ing action tends to propel it in the direction in which it is travelling. In order 'to reduce or indeed to suppress these inequalities in effort one can arrange, either on ca-m 61 itself as shown on Fig. 20, or on a distinct cam fixed to shaft 15 ramps 63 on which lever 64 acts. This lever is solicited by a balance spring 641 the action/fof which on ramps 63 is always equal and opposite to that of clutch spring 60. The effort necessary to rotate the shaft is thus balanced and can be made constant.

By giving cam 63 a suitably selected shape one can obtain any other result that might appear interesting; for instance one might mak-e shaft 15 cockspring 641 at the beginning of the -rotation necessary for a change of speed, the release of the spring causing shaft 15 to complete its rotation.

In addition to balancing shaft 15 ramps 63 of cam 61 and spring 641 propel it.

Itis to be noted' that in propelling shaft 15 the propelling mechanism stops shaft 15 10orrr Lacasse Y exactliy at eachposition corresponding to the utilization of the combinations.

Suitable mechanism for rotating shaft 15 in the direction and over the angle required can be most varied andFig. 19 shows only a few characteristic examples.

0n Figs. 19 and 20 shaft 15 is driven through transmission by shaft 66 of an auxiliary electric motor 661 an electric switch 67 controlling rotation in .either direction or stoppage. I

The extreme positions of this switch are determined by those of lever 14 controlled by a neutral gear-shift-differential device K, of any type and positions corresponding respectively to upward or downward combination changes. The neutral position of switch 67 corresponds to the stoppage `of motor 661.

On F ig. 21 shaft 66 is always driven in the same direction by an outside electric source, for instance a rotating shaft in the boX, an auxiliary electric motor, etc. This shaft 66 through any mechanical reverse system 68, drives in an oppositeldirection two wheels 691 andl 692 fitted loose on shaft 15 but which can be made solid with it by means of clutches 701 and 702 of any type, for instance electro-magnetic, which are thrown in or out of action by lever 14 of gear-shift K which in the case considered, is connected to the electric source. and through contacts .,381 and 38.2, can send current into the desired clutch.

ln the case where shaft 66 is driven by an auxiliary electric motor which maybe, as shown in Fig. 22, 66a which starts the engine ofthe vehicle it is sufficient to cause this motor 66a tobe put in\or out of action, under the control of the gear shift, at the moment when a change is to be effected.

Confusion between the two offices fulfilled by the said motor 66a, must be avoided and for this purpose one acts on moving organ 66b which ensures temporary engagement withthe engine when starting, a ybolt 66C,

which prevents engagement so long as the driver has not removed it by control 661 which he operates when starting. At this moment a contact 66e on the said bolt, cuts of the current which feeds the shift so that since the coils of clutches 701 and 702 cannot be excited, the rotation of motor 66a does not drive shaft 15 which controls the changes. 0n' the contrary, when the bolt has returned 'to its place, the moving organ cannot establish connection with the engine of the vehicle when rotation is caused with aview to rotating shaft 15 and, at this moment the gear-shift is normally fed with current.` It may be'advantageous to cause the starting of motor 661 a little before sending current y to coils 701 and 702.

For this purpose, on the free end of lever 14 one hinges a small lever 14x normally held inline with the former by spring 141', this lever 14", when lever 14 is inclined one way or the other, comes into contact first with a contact 382 or 381r to start motor 66a, next with contact 381 or 382 which feeds the corspeeds) Fig. 23, shows another arrangement of control of shaft 15 which transforms the rotation in one direction of shaft 66 into a rotation, in the desired direction, of shaft 15.

Two plates 811 and 812 are arranged to constitute ratchet wheels acting in opposite directions and these are keyed onto shaft 15. A/lever 83, articulated on shaft 15, oscillates under the control of a crank lever 84 driven by shaft 66. The amplitude of the oscillation is greater than the space between two teeth, if there is no driving mechanism, or greater than half this distance, if there is a drive as specied in the case of F'ig. 20. This difference determines the amplitude of the rotation of vshaft 15. The free end of lever '83 bears two pawls 851 and 852 acting in opposite directions, placed respectively opposite cogs 821 and 822. The pawls are keyed to their axes 86 which also carrieslever 87 the free end of which fitted with a roller is engaged in a circular slot 88 which has 'shaft 15 for its center, and hollowed out for instance in a plate 89 capable of being displaced directly or indirectly by lever`14l of one of the gear-shifts K of the neutral position type such as described. So long asl part 14 occupies the neutral position, neither of the gear then engaged is retained. If plate 89 is displaced bythe action of the gearshift, say towards the' right of Fig. 23, lever 87, by tipping permits pawl 851 to reach teeth 821. This pawl therefore'causes corre- Y sponding plate 811L and also shaft 15 to turn the space of one tooth. During the oscillation in the opposite direction of lever 87,

.pawl 851 slides along the following tooth 821 .the two pawls can acton cogs 821 or 822 and 1 shaped pendulum 90, the lower arms of which penetrate respectively into coils 911 and 912, each capable of attracting the corresponding arm when excited by an electric current at the moment when lever 14 makes contact with electric contact 381 or 382 established in its circuit.

Figs. 24 and 25 show an arrangement pernext. Longitudinal movement is effected by.

a cam 177 tted loosely to shaft 15 and in which a slot 178 has been made to accommodate roller 179 fixed to rod 180 guided byrod 181 parallel to the slots. This rod bearing at the end opposite to that of the roller,

a sliding sleeve 182 bearing part 176 an'd drawn towards the roller by spring 183.

The transverse movement is controlled by a plate 184 sliding on the gate and against which part 176 presses constantly due to spring 183. If plate/184 propelled by cam 185, keyed to shaft 15 covers the slot uniting the two slots, the longitudinal displacement of the part will follow the said slot. If, on the contrary plate 184 uncovers thecommunication slot, part 176 follows the slot it is engaged in until it can enter this passage and under the action of spring 183 pass into the next slot when its movement stops. To reverse the movement, cam 185 tends to move the plate forward and is prevented `from doing so by part 17 6. Another spring, inset between plate 184 and its control lever 187, is compressed and as it is more powerful than spring 183, it pushes part 176 back through the communication slot as soon as it comes opposite the opening during its longitudinal movement. Y

Cam 177, mounted loose on shaft 15, is driven by cam 185 with a slight retard to enable part 176 to effect part of its longitudinal movement before commencing, in case of need, its transverse movement. Whatever arrangement may be selected it will be seen that shaft 15 can always be made to turn in the necessary direction and by the exact angular amount to ensure the changing over between combinations whether upward or downward. In the case -of four combinations (three changes) the angular displacement for a change may be of any importance providing it is equal to or less than one third of the circumference.

For the sake of convenience in giving explanations the value of the angle has been taken as a fraction of the circumference the denominator of which is equal to the number of the characteristics positions of the said shaft (1 /4 for four combinations).

One should note that in the case of snatch gear-boxes such as that shown in Fig. 20, the automatic operations are not suflicient to ensure a proper change. The operation of ordinary (non-automatic) gear-boxes of this kind effected by a driver necessitates at least five operations: 1, The driver begins by releasing the accelerator to arrest power production and limit the speed of the engine `during the following declutching;'2, he declutches the engine, as this is indispensable, to permit of the displacement of the sliding gear; 3, he makes the gear slide in the correct direction to engage with the new combination; 4, he letsin the clutch with the engine which has assumed a new speed; and 5, he presses on the accelerator so as to resume normal functioning. i

As levers 62, 62FL and 62b (Fig. 20) effect the automatic operation of the sliding gears Without the knowledge of the driver, the latter, having no indication, leaves the accelerator in any position. A special device has to be provided, hereinafter denominated synchronizer (Figs. 26 to 29) which will intervene in order to limit the speed of the engine when it is automatically thrown out of gearv by cam 61 and lever 62. The synchronizer may moreover be so designed that in addition to its principal function (Fig. 26) it may ensure the engagement of the sliding gear into the new combination by realizing an approximate but sufficient synchronization (Fig. 27) or an absolutely correct synchronization `(Fig. 28) between the gears that are to be engaged, and indeed to prevent engagement" until synchronization of the gears has been attained.

On Fig. 26 the main shaft of the engine or any other shaft connected with it in rotation has been denominated 2a and 2* denominates the shaft revolving with shaft 2between themain clutch (Fig. 19) and the gearbox. The whole is therefore erected in parallel with the main clutch 60 of the vehicle. Shaft 2a driven by friction member 93, with properly loaded springs 931, a tapped sleeve 94 on which is screwed a nut 95 driven by shaft 2h but sliding along it.

If shaft 2a turns faster than shaft 2", nut 95 will move in relation to the said sleeve away from friction member 93 and it moves with it part 96 with finger 961 from the position marked in solid lines in Fig. 26 to the position shown in dotted lines. This finger alsofrees a tappet 98 which, propelled by spring 99, breaks, at 971 the ignition circuit of the engine, which reduces the speed of shaft 2a. As soon as this speed becomes lower than that of shaft 21 the nut screws in the opposite direction on sleeve 94 until finger 961, pushing back the tappet, re-establishes ignition circuit 97. An equilibrium is thus established which constantly maintains shafts 2 and 2b at practically the same speed.

in order that the synchronizer may only intervene during the declutching periods, tappet 98 is also maintained in the position in which it permits the ignition of the engine, by a bolt 100 borne by rod 101, connected to the mechanism 62 of the main clutch (Fig. 20). Vhen this loosens, the bolt moves in the direction of the arrow,(Fig. 26) and leaves ta ppet 98 under the sole control of the synchronizer.

When'the clutch is engaged, bolt 100 reestablishes ignition by compressing spring 99 whatever the position of the synchronizer may be at that moment.

If one completes the lay-out described in,

Fig. 20- by a synchronizer of this sort one obtains the following working. lVhen there is a change, the gear-shift, coming into anactive position, sets in motion in the proper direction, as explained (Fig. 20) shaft 15 which, from the commencement of its-rotation, releases the clutch, sets the synchronizer into action by removing part 100 and the gear box transmits no power. i

The sliding gear concerned 1s not yet thrown out of gear; in consequence shaft 2b being still connected through'it to the driving wheels retains, practically the same speed it had when the operation commenced, for example c1 if the change is upward. The engine controlled by the synchronizer therefore also retains this speed; the release of the sliding gear previously in operation, then the throwing in gear of the new one, are easily eii'ected since the gear-box is no longer transmitting any effort and everything happens as if the driver had effected the proper operation; but the engagement of the sliding gear has resulted in causing an off-set on shaft 2b which` exists between speed v1 and o2 or else o2 and/(o1 as explained in Fig. 1. The synchronizer immediately imposes this modilication in pace to the engine and the operation closes by normal engagement of the clutch although the driver who has no warning, has left his accelerator in an indefinite position; and the car proceeds on the new combination.

A In the above description the synchronizer is used only to control engine speeds while out of gear.

One can also employ a single synchronizer to ensure sufficient synchronization of the speed of the gears to be engaged. Fig. 27 shows the lay-out of a synchronizer of this sort established and controlled by the clutch as set forth for Fig. 26, but which, acts on .tappe't 98 cutting out the ignition of the engine through rod 96 connected to the end of rocking lever 962 the' other end of which controls tappet 98.

Between any one of the operating arrangements described Figs. 19, 20, 23 and 30 and shaft 15, a driving mechanism has been provided consisting for instance of a tapped sleeve 104 engaged on a threaded part with a long and reversible pitch, of shaft 66. Sleeve 104 carries extensions 105 engaged in slots 106o provided parallel to the axis in a fork 106 solid with shaft 15. The displacements of the sleeve, in both directions are transmitted by rod 102 in the center of roeking lever 962 and are limited by two cheeks 1071 and 1072. The result is that in order that shaft 15 may be driven by shaft 66, sleeve 104 must be in contact with one or the other of its checks according to the sense of rotation of shaft y66.

Sleeve 104 is returned to its neutral position by springs 1091 and 1092. f Y

The functioning is as follows: Contrary to what has been explained for Fig. 26, the synchronizer does not enter into action immediately the main'clutch is loosened but one-endeavors from that moment, to bring the engine in the neighbourhood of the speed it should have for the engagement of the new combination, that is to say of corresponding driving ,speed 'v2 if the upward change is commenced at v1 because speed o2 is that which gives exact synchronization of the gears. The off-set in the speeds which must slow up the engine if the change is upward, is obtained for instance by acting on the ignition by means independent of the synchronizer and it is only when engagement has been effected that the synchronizer enters into action to keep this speed correct until the -moment when the main clutch is tight.

These independent means are constituted by sleeve 104, which for an upward change makes contact with its check 1071 due to the direction of rotation of shaft 66 and this displacement, through rocking lever 962 always interrupts the ignition of theengine notwithstanding the position of the synchronizer and this in any case diminishes the original speed 'U1 and brings it nearer to fv2. If the change had 'been downward and consequently commenced at o2, sleeve 104, contacting with its check 107 2 would have maintained v ignition notwithstanding the position of the synchronizer and vas at this moment the main clutch is loose there is an acceleration of the engine from o2. to '01.

During this deceleration or acceleration of the engine shaft 15 continues to rotate and successively causes the throwing out of gear of the gears of the combination that is being abandoned and the engagement of the gears one is taking u p. At this moment shaft 15 has effected half a turn and the propelling mechanism intervenes so that no power may be exerted through sleeve 104. The latter

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