USRE23326E - Device fob control and operation by - Google Patents

Description

6 v 2 3, 3 2 a R Jan- 9 1951 G. FLElscHEL DEVICE FOR CONTROL AND OPERATION BY FLUID SERVOMOTOR Original Filed April 27, 1957 6 Sheets-Sheet l Jan. 9, 1951 G. FLElscHEl. Re- 23,326 DEVICE FOR CONTROL ANO OPERATION BY FLUID sERvOMOTOR Original Filed April 27, 1937 6 Sheets-Sheet 2 Y Y Y dfardey DEVICE FOR CONTROL AND OPERATION BY FLUID SERVOMOTOR Original Filed April 27, 1937 6 Sheets-Sheet 3 @RQW fro/wey:

Jan. 9, 1951 G, FLElscHEL Re. 23,326

DEVICE FOR CONTROL AND OPERATION BY FLUID SERVOMOTOR Original Filed April 27, 1937 6 Sheets-Sheet 4,

G. FLElscHEL Re- 23,326 DEVICE FOR CONTROL AND OPERATION BY FLUID SERVOMOTOR Original Filed April 2'7, 1937 6 Sheets-Sheet 5 Jan. 9, 1951 i if, 1111 Jan. 9, 1951 G FLElSCHEL Re. 23,326

DEVICE FORl CONTROL AND OPERATION BY FLUID SERVOMOTOR Original Filed April 27, 1957 6 Sheets-Sheet 6 222 225 jgjf @@QQM Reccued Jan. 9, 1951 23,326 l DEVICE FOR CONTROL AND OPERATION BY FLUID SERVOMOTOR Gaston Fleischei, Bleneau, France Orililil N0. 2,203,296, dated June 4, 1940, Serial No. 139,321, April 27, 1937. Application for reissue August 21, 1950, Serial No. 180,631. In

France May 7,1936 58 Claims.

Matter enclosed in heavy brackets 1 appear (C1. 19E-.07) s in the original patent but forms no part o! this reissue specification; matter printed in italics indicates the additions made by reissue The invention relates to devices for control and operation by uid servo-motor; and it concerns more especially devices of this type utilised for the control and operation of .transmissions for automobiles.

It has vfor its object, particularly, to make these devices such that they adapt themselves, better than at present, to the particular conditions in which these servo-motors must operate under the control of a selecting means (manual or automatic) to carry out a determined operation. More particularly, the purpose of the invention is to provide a control device for a iiuid servomotor which is arranged to change thegears in an automobile transmission, in which the distributor for the energizing fluid of the servomotor is controlled in any suitable manner, with means operated by a force dependent on a modification o1 the operation of the transmission mechanism to control the distributor.

According to the invention, and more especially according to that of its methods of application as well as those of the methods oi realisation of its various parts, to whichv it seems necessary to give preferencefvproposmg to construct a device for the control and for vthe operation, by iluid servo-motor, of avariablespeed transmission for automobiles, one proceeds as follows, or in a'vsimilarmanner and referrin to the drawings v-wherein:

Fig; V1 shows a.diagrammatic.elevationlmxirtsz in section) the 'ofaf variable speed transmissionv vention. l

2 shwsfon'a larger scale, theoperatingfr mechanism I or the clutch o1' the transmissionV according to Fig. 1.

Fig. 3 shows an explanatory diagram of the operation oI the controlling'and operating mechanism of such ha. clutch.

Fig. 4 shows, in elevation (part partA of an operating mechanism of the l, clutch of the transmission accordingto Fig. 1. .but-constructed according to a.vs .ris'ttich.A

Fig; 5 shows, in elevationipartsin sectioni anotherA variation io! ga' controlling and .operating mechanisme! laiclut'cl'i of the cordingV to Fig. 1. 'f

constructed according to'the inin section), a,

transmission acvice constructed according to the invention, for an entirely automatic transmission. i

Figs. 9a, 9b, 9c and 9d show, in transverse section, respectively tour characteristic positions of a distributor forming part oi' the device according to Fig. 9. f

Fig. 10 shows, partly in elevation and partly in vertical section, a ilrst modication of a control arrangement similar to that shown in Fig. 9.

Fig. 11 is a similar view of a modiilcation of the control arrangement according to Fig. 10, in which two nuid 4distributors are combined into a single device.

Fig. 12 shows in a similar manner a modification of the arrangement of Fig. 11, in which the device is operated on by two variable control forces. v

Fig. 13 shows, on a larger scale and in vertical section, a control device for the brakes o! the transmission shown'on Fig. 1.

There is designated here by the term fluid servo-motor and in the most general manner, any device which, under the control or the supervision. of a'selector .mechanism functioning automatically. orV through the interventionv of an operator, furnishes at theleast partially and with the aid of an energy suitably accumulated in a iluid (liquid .or evenV gaseous),` theiorces lnecessary for the carrying-out of certain determined .operat1ons, while strictly observing the selections given by the said selector mechanism. A movable member, -called distributorfor the servomotor,.' puts the servo-motor intoV and rmt-foi? action, .for..exa1 nple Vby admission, by

gradual' regulation or Yby suppression, of the energy accumulated in the driving fluid under the control of the selecting mechanism.

In order to explain the object of the invention there have. been shown on the drawings transmissions for automobiles ot a standard type `comprising, for acting on thev wheels of theanisms capable of resisting the propulsion when .it becomes excessive or must be suppressed, such as the brakes of the vehicle. After the description of these examples it will be shown that the invention can also be applied to transmissions oi'- a different or more particular kind.

xmatic. It will be assumed, in the following, that the fluid utilised in these servo-motors is a liquid and more especially oil under pressure which can be that which is used for the lubrication o! -by an oil servo-motor under the engine or of the transmission. Of course, recourse could be had to any other source of pressure dierential for power.

The oil under pressure can be furnished from any suitable source. However it may seem preferable to provide a special circuit for the supply of the servo-motor or servo-motors for example in order to utilise an oil different from 'i that which lubricates the engine and to4 this endy the following procedure may be adopted.

There is provided on the casing of the en- Eine A an oil reservoir I in which is accom- -modated a pump 2, for example a gear-wheel pump, which is driven, through the intermediary of a pinion 3, by the engine A and particularly by the cam shaft 42 of the latter. The oil under pressure is delivered through the conduit 4 and the return of the oil into the reservoir I takes place through the discharge tube 5. As the pump functions constantly and as the operations by servo-motor only take place intermittently, there is provided in the delivery conduit 4 a valve Ii which limits the pressure to the desired value and permits thedischarge of the oil into the piping 'I where it can be utilised for lubrication for example. It is of interest vthat the oil of the servo-motor is that which lubricates the transmission, but it can be dierent from that which lubricates the engine or the transmission, l.the return of this oil taking 'place through the tube 8 (Figs. 1 and 2).

The friction clutch B, provided between the engine A and the variable speed gear can be engaged, in the usual way, by springs (not shown) and can be disengaged through the intermediary of radial levers 9 pivotcd at ilxed points and the outer extremities of which tend to separate the friction linings of the clutch against the action ofthe said springs when the sleeve I0, capabe of sliding about the input shaft II oi' the variable speed gear is displaced axially towards the left of Fig. i. This displacement can be assured by a pedal operated shaft I2 or pressure constituted, for example, as follows.

In the end wall I3 of the clutch casing there is provided, concentrically to the shaft II, an annular chamber I4, connected to a tube I 5 fllled with oil and opening into a distributor G regulating the pressure transmitted by this oil. The annular chamber I4 communicates, moreover, by passages I8 with several small cylinders in which are accommodated fingers I1,

forming pistons and capable cf driving the sleeve III back against the vaction of the clutching springs when the distributor G establishes communication between the delivery conduit 4 of the pump and the tube I5. There is thus ob- 1 tained the disengagement of the clutch B and the uncoupling of the connection between the engine A and the variable speed gear. On the other hand, when the distributor G vinterrupts the above-mentioned connection and connects the tube I 5 to the discharge tube 5, the pressure diminishes or ceases to act on the oil supplying the servo-motor I4-I1 of the clutch and the springs of this latter produce its engagement.

For the 'example shown on Fig. l it has been supposed that the variable speed gear comprises a reversing device C separate vfrom the variable speed gear D and E and which is arranged, as is well known, insuch a way that when its operating arm IB occupies its medium position all connection is interruptedbetween the variable speed gear proper and the assembly constituted 4 by the engine A and the clutch B. When the said arm IB occupies one of its extreme positions, the shaft II of the clutch is capable of driving the members of the variable speed gear D in the same direction and for its other extreme position the drive takes place with reversal of the direction of running. The operating arm I8 is remotely controlled by the driver, for example with the aid of a handle I8 (or of a lever) with three positions and connected to the said arm by a flexible or articulated connection 2li. The reversing device is of absolutely any type and occupies absolutely any position. In the preferred form, however, the lever in its mean or central position disengages the reversing device so that no d'rive takes place therethrough. Displacement of the lever towards the right (in Fig. l) causes forward drive, while displacement towards the left causes reverse drive. 1

The variable speed gear comprises, for the example according to Fig. 1, two simple planetary gear-boxes E and D, which are mounted end to end whi.st having different transmission ratios. Moreover, the gear box E is operated by an independent servo-motor with which is associated the distributor E1 independent ofv that D1 of the other gear box D. As the constitution of the -two gear boxes-with the exception of the ratio of the gearsis the same there has only been shown in section the box E which will be described in detail hereafter.

The box/is provided, in the usual manner, with three groups of members. One driving group 2I is driven by the output shaft 22 ofthe gear box D and comprises for example a planetary gear 22 with interior teeth. This gear meshes with satellites 24 mounted on a support 24a'keyed on the output shaft 25 of the gear box E. A central sun-wheel 26 constitutes, for example again, the third group which it is desirable to engage with another group, more especially with the planetary gear 23 in`order to obtain the direct drive of the shaft 25 for the simple gear box E considered. 0n the other hand when the central sun-wheel 2B is held by braking with respect to the casing of the gear box E, the drive of the shaft 25 takes place at a reduced speed through the `various gears. For this purpose there is mounted with a long keyway and on the hub oi' the central sun-wheel 26 a plate 21 carrying a peripheral rim for example double-coned. The said plate 21 is constantly urged towards the planet 23, integral with the input shaft 22, by a spring 29, for example, a resilient ring of concave form. When this spring can act freely, the conical part 2i!EL of the rim is applied on the conical edge of the planetary gear 23 which assures the direct drive of the shaft 25 by the shaft 22. In order to obtain the driving ata reduced speed it is necessary to force the plate 21 back axially against the action of the spring 29 until the conical part 28h comes into contact with a fixed rim 30, of corresponding shape and mounted on the casing of the gear box E. Such a forcing back is obtained through the intermediary of an annular part 3l capable of sliding axially in its housing in order to come into contact with the peripheral rim of the plate 21 and in order to force this latter back which, at ilrst, separates the conical part 2l'l from that comprised by the gear 23, and then applies the conical part 28' against the xed rim 30. 'I'he axial displacement of the annular part 3i is obtained by the pressure of the oil by the pump 2 and transmitted by a conduit 35 to the dis- -tributor E1 which, by being brought toits admission position, allows this pressure to act through aconduit I8 in an annular chamber I2 provided in the lateral wall of the gear box E, this chamber communicating 'by passages 33 with housings in which can slide fingers I4, in the form of small pistons, which act on the annular part 3| in order to force this latter back as indicated above.

When the distributor E1 is brought to its exhaust position, the conduit 36 is put into communication, by the pipell, with the discharge pipe I in such a way that the pressure ceases to act in the chamber 32. Under the combined action of the spring 29 and of the return springs ,f Il, the annular part is forced back axially towards the left of Fig. l, which separates the conical part 2lh from the fixed rim l0 and again brings the conical part 28* of the plate 21 into contact with that of the planetary gear 23 to re-establish direct drive. Under the action of basso sible. For an ordinary and non-automatic fric` any moment. are ready to come into action to its return springs 38 the annular part is` then separated from the plate 21. The gear box D has a similar constitution and 'its distributor Dl can supply this box with oil under pressure through the pipe 39 whilst the discharge takes place, advantageously, through the common pipe I1.

.It yshould be noted that this type of planetary gear box permits the employment of its friction surfaces 28n and 28 without any dead point since it is precisely the putting into contact of the frictional engagement affecting the new ratio which causes the abandonment of the former ratio. The changing of the speed combinations can Atherefore take place at full load,`which is an important advantage. Moreover the cornbination of the two simple gear boxes, of nearly similar ratios, permits of obtaining four speed ratios the engagement of which can be effected at full load.

Regarding the brakes of the vehicle, there has only been shown the transmitting rod 4|)1 which controls these mechanisms, which are constructed in the usual way, as well as a servomotor 40 with oil under pressure or the like which `serves for the operation of the brakes, this servomotor being able to be combined with that which usually controls the brakes by the braking pedal or distinct from this servo-motor. It will be explained hereafter how the oil is supplied and 4distributed to the servo-motor 40.

Having thus described the essential members assure a suitable engagement or disengagement of the clutch. Thus during'the starting period it is necessary that below a certain speed of rotation V2 of the engine the clutch is completely disengaged, that above the speed of rotation V2 the engagement commences and increases when the speed of rotation of the engine increases, and that according to another speed of rotation V1 of the engine, the engagement is complete.

In order to control the clutch there is preferably utilisedA a centrifugal governor 4I driven by the engine, particularly by the cam shaft 42 of the latter, this governor comprising for example a ball cage 43 with cylindrical housings inclined =for example at 45 on the shaft 42 and in which are accommodated balls of the governor 4I. These latter are projected, by the centrifugal force, against "a cone 44 movable axially and which, through the intermediary of an oscillating lever 45 and of a connecting rod 4B, acts on the slide valve 41 of the distributor G forthe servo-motor |4-l1` of the clutch B. As the governor 4I need only displace the slide valve 41 of light weight and slight friction and without being influenced by the reactions which' are produced during the operations of the clutch, this governor can be constituted in a simple, economic and little cumbersome manner and its action, as an actuating and controlling mechanism, is made more sensitive and more efiicient.

The slide valve 41 is appointed to control the servo-motor I4-I1 of the clutch vB during the starting and stopping of the vehicle. This slide valve is shown on Fig. 2 at its mean position for which it closes at the same time both the outlet 48 of the delivery conduit 4 of the pump 2 and the orifice 49, through which the oil can escape towards the discharge pipe 5. 'I'he inlet 50 of the feed conduit I5 of the clutch servo-motor |4-I1 occupies such a position that it is never covered of the transmission to be constructed as well as the servo-motors through the intermediary of which the oil under pressure can assure theoperation of these members, there will be set forth hereafter the actuating or these servo-motors. f y

Regarding the clutch, it is proposed to render this control entirely automatic as much during the starting and stopping periods of the vehicle as during the changes of the speed combinations,

controlling means for the methods of operation of the clutch during these operations being, as is well known, essentially different. It is known, in effect, that during the starting the engagement of the clutch must be suitably and progressively controlled according to the running of the engine and of the vehicle, a too-slow engagement causing raci ing of the engine and a too-rapid or abrupt engagement the stalling of this latter. On the other hand. during the speed changes the operation of the clutch must assure a more or less decisive disengagement and be as rapid as posby the slide valve 41.

The slide valve 41 is influenced by a return spring Il the stress R of which acts in the opposite direction to the thrust of the force X of the centrifugal governor 4|.

Such a control is already self-regulating for so long as the centrifugal force X remains lower than the power B, of the spring, that is to say as long as the speed of rotation of the engine is less than V1, the slide valve 41 is pushed back by the spring il towards 'a position for which the outlet 4l is uncovered in such a way that the pressureof the fluid acts through the pipe l5 and disengages the clutch. If the operation of the engine becomes such that the force X exceeds the power R of the spring, that is to say that the speed of rotation W is exceeded, the slide valve 41 is moved towards a position for which `,theoutlet 4B is closed and the discharge orice 49 uncovered, which permits the engagement of Lthe clutch. It the e'ort thus required from the engine is high, itv slows down;.A the force X diminishes from this fact until the outlet 48 is opened and the discharge orifice 4'9 closed, which causes thedisengagement of the clutch. This disengagement unloads the engine which accelerates and thus causes the engagement ofthe clutch. There is consequently obtained an auto? regulation leading to a stable state of equilibrium. but the energy utilized is completely brought into action or totally suppressed, which action may cause unpleasant jerks in the operation.

In order to obviate this disadvantage the slide valve I1 is arranged in such a manner that it is capable of undergoing a reaction from the oil pressure. This reaction is, of course, chosen with the same orders of magnitude as those adopted for the centrifugal governor i andthe spring 5I. .In this way, a progressive variation of the pressure of the oil is made to intervene between the two extreme values of said pressure which corresponds respectively to .the engagement and disengagement of the clutch.

This reaction is obtained by adopting a partial equilibrium for the slide valve I1 by giving different values to the diameters of the obturating parts of the slide valve l1. The transverse section of the part l1- which can obturate the outlet Il is, for example, smaller than that of the part 41h which can obturate the discharge orice I9. 'Ihis difference in diameters gives rise to an axial thrust P proportional to the pressure of the oil and to the difference of the sections and directed, in this case, in the same direction as the force X of the governor 4l and against the power R ofthe spring Il.

In order fully to understand the important modifications thus applied to the operation, it is expedient to examine the diagram of Fig. 3. In this has been ,shown as abscissae yalong Ov the speeds of rotation of the engine and as ordinates along OJ, the different forces which act on the slide valve I1 of the distributor G.

The force X of the governor is indicated for a speed of rotation V of the engine, by a variable force VC the extremity of which C Vis always on the parabola Xcorresponding tothe centrii'u'' gal force produced by the'govemor 41|'. The constant power of the spring Il is indicated by the horizontal R. l

At ax'ry speed o frotation VA ofthe' engine, the force' VC, developedby' the centrifugal governor 8 the value corresponding to the thrust CF of the diagram and that this pressure gradually changes at the same time as the thrust CF when the speed of rotation V of the engine varies, and this in spite of the fact that the oil pressure' produced by the pump 2 is constant.

vthe engagement which is Anull at "V3, increases an'd the P- resultingfrom -the"pressure of the-oil on tlienned'ual surfaces ofthe slide.

valve 41 are together iorthey are in the same direction, and. their-sum" is" in opposition t0 the power- Rihffthesprlhg IH.' Y Therefore, atgany speed of'rotation V 'of the." engine, the slide valve Il is only inequilibrium if 'the pressure otthe oil. in the distributor G, has

auch a value that the/thrust it develops is equal to CF. If thepressure P were lower, the spring Bi would 'superiority and the slide valve 41 would uncover the outlet Il for the oil under pressure in such a way as to increase the. pressure until the thrustP has "reachedlithefvalue CF, at which "value moyementwould stop` due to equilibrium of vthe-forces. on theslidevalve.l

111', 'on the contrarypthepressnre became excessive, that'ist'o say vthe thrust- P greater than CF thecombined forces X and" P,l would become greater than R and the slide valve would be displaced in,.ftl'le; opposite directionl which, after having; if'ne'cessary, interrupted the supply of oil under pressure through the outlet 48, would uncover the discharge oriilce 49 for the pressure.

The pressure of the oil downstream of the distributor hasl therefore become a variable which, in this case', is a function of the speed of the engine'but which could quite as well be made a function of any other functional factor of4 the engine or of the vehicle. This progressive variation, which is utilised for the operation of the clutch between the speeds of rotation V2 and Vx of the engine, is added to the auto-regulating operation mentioned above, in order completely to eliminate the jerks which the operation by all or nothing would have been able to allow to exist.

The variation of the forces which act respectively in this case on the slide valve 41 summarised by the formula v As X is variable and R constant, P is necessarily variable 'asl a function of X.

It is advantageous to dimension the active surface of the piston or pistons I1 of the servoclutch, in such a wy that for a pressure of the oil giving a thrust greater than CF, which corresponds to the speed of rotation V2' of the engine, the clutch B is completely disengaged and applied. for example, against a projection which l absorbs the 'excess thrust developed; and so that at the speed of rotation Vl of the engine the pressure becomes ineectual with the thrust, as shown by thediagram at the point C1. it is sumcientthat the power R. given to the spring BI is equal to the centrifugal force V101 developed at .the speedloi' rotation V1 of the engine.

Between the two speedsof rotation V2 and V1 with the speedV of 'rotation oi' the engine in order to become complete at the speed of rotation V1. I'hisweryv progressive engagement, the -limits V1 and V2 of which can be chosen at will with a view `to the better result to be obtainedand which intervenes for anoperation already auto-regu? lating'by itself, eliminates all jerks during ystarting;'-vvhatev'er `m?' Y be 'the speed at which this vlatter takes place. Moreover,.an ,operation has been obtained according to the so-called "cenu trifugai" principle of the clutch without modifying the standard clutch in any way and without interposing in the clutch itself heavy rotary masses, which is a very substantial advantage from the constructional point oi view.

Again, other important improvements can be very simply applied to the device such as described It is proposed, for example, to avoid,

with the control described, a characteristic defeet of centrifugal clutches with rotating masses. With these latter, in consequence of their almost symmetrical operation when it is aquestion of an engagement by acceleration of the engine or of a disengagement by slowing-down, it is very difficult to determine the speedsof `rotation V2 and Vx of the engine so that they shall be equally favourable in both cases. Generally a progressive disengagement is useless and it commences too soon at the speed of rotation Vx upon slowing-down. On the -other hand if the speed of rotation V1 for which the disengagement commences is lowered. the engagement at starting is terminated at a too-low speed of rotation of the engine tot 9 which it does not yet develop a sufficient couple. It can easily be obtained with the device, such as described. that the mode of disengagement of the clutch at the time of Aslowing-down shall be different and shall take place at a speed of rotation other than that for the engagement at the time of starting. This permits of adopting the most advantageous values for each case.

If it is desired for example that the disengagement shall only take place at a speed of rotation V3 of the engine, completely independent of the speeds of rotation V1 and V2, it is sufficient to provide, as shownkon Fig. 4, in the slide valve 41 (or in a part integrall in movement with this latter) a peripheral groove or notch l2, with wh* ch co-operates a bolt |53, influenced by a spring 54 of constant or regulatable power. The engagement of the bolt 53 `in its housing 52 can only take place when the slide valve 41 occupies a position for which the clutch is completely engaged, that is to say for which the outlet 48 is closed and the discharge orice 49 completely open.

When thev driver starts up, the slide valve 41 leaves its position at the left of Fig. 2 or 4 and slides gradually towards the right under the thrust of the force X. The bolt can only engage 5 in its housing 52 when the engine has definitely exceeded the speed of rotation V1 for which the complete engagement of the clutch is obtained so that there is no changeA for the engagement during starting.

The engagement of the bolt 53 in its housing l2 brings into action a fourth force. namely the constant force Y due to the retaining action exerted by the bolt 53 on the slide valve 41 and which depends upon the power of the spring 54. This torce Y is chosen in such a way that it is equal to the value C3111 of the diagram of Fig. 3

As a result thereof, for a speed of rotation V of the engine for which the centrifugal force X is equal to VC and the retaining force Y equal to CUC4 the pressure of the oil can only be equal to CF. If the declutching speed of rotation V3 mines the commencement of the engagement on starting and if the engine slows' down and successively passes through the speeds of rotation V1 and V2, the slide valve 41 nevertheless remains at its position for which it closes the outlet 48 and thus prevents the disengagement of the clutch up to the moment when the speed of rotation V3 is attained. The slide valve 41 is then freed from the bolt 53 and the conditions of operhas been chosen lower than that V2 which deteration regulated by the parabola X are again suddenly met with and the pressure of the oil rises abruptly to a value for which it is capable of developing on the slide valve 41 and thrust 03F. This pressure assures the instantaneous and favourable disengagement since a pressure giving a thrust corresponding to C111'z is only necessary to obtain this result.

The control devices described above .can be completed by means permitting of obtaining a variable condition of engagement for the clutch, and by which it is therefore possible to modify, at will, the speeds of rotation V2 and V1 for example in order to be able, exceptionally, to make the engine rotate at a high speed for diflicult starting conditions (sticking ofgthe vehicle. starting on a very accentuated slope, etc.)

It may be desired, although this point is open to discussion, that the variation of the speeds of rotation V2 and V1 of the engagement of the clutch shall take place automatically according to the load of the engine. these speeds of rotation beng lower when the engine is not loaded than when a considerable effort is required from it.

For this purpose, as shown on Figs. 1 and 2, there may be brought into action the suction which exists in the suction pipe of the engine hy making it act through a conduit 62 on adaphragm 33 accommodated in a chamber 64. The diaphragm G3 is connected to a rod 65 on which is arranged the spring l5 and which includes an abutment 66 by which the action ofthe said spring 55 on the slide valve 41 can be modified as a function of the momentary value of this suction. When the suction is a minimum (which corresponds to a heavy load of the engine). the diaphragm 63 is at the position shown on Fig. 2 for which the power of the spring |55 is added with a maximum value to that of the spring li, which raises the speeds of rotation for affecting the clutch, as explained above. On the contrary, when the suction becomes greater, for light loads of the engine. the diaphragm 63 drives the rod 85- exerted by the supplementary spring 55 by lowering in this way the speeds of rotation for the clutching operations. If necessary the remote' control 56-51 can intervene to modify or correct this automatic employment of the suction by more or less compressing the spring 55 through the intermediary of a sleeve'61 capable of sliding on the rod 65.

On Figs. l and 2 there is shown an arrange ment comprising a cranked lever 6B pivoted to a lug 69 which extends from the slide valve 41. One arm of the lever 68 carries a roller 10 cooperating with a xed rolling path 1I which has a step 12 in which the roller 10 can engage when the' slide valve 41 comes to occupy a determined position and corresponding to a speed of rotation of the engine higher than V1 as explained with regard to the retaining bolt 53 and the groove 52 of Fig. 4. This lever 68 is influenced by a spring 13 which bears against a member 14, for example carried by the lug 69, and which tends to apply the roller 1U on its rolling pathr 1l, the calibrated power of the said spring 13 fixing the speed of rotation V3 for disengagement. The lever 68 is also iniiuenced by the rod 85, freely in contact with it and through the intermediary of which the spring 55 tends to apply the roller 1D on its rolling path with an intensity equal to that by which it reinforces the spring 5I.

When the suction is very slight (full charge to the engine) the diaphragm 63 occupies the position shown on Fig. 2 and the main spring 5| as well as the auxiliary spring 55 are of full value.

The speeds of rotation V2 and V1 of the engine, respectively determining the commencement and the completion of'the engagement of the clutch have their maximum values. The spring 55,

sasso which applies the roller 1li on its rolling path,

determines the speed of rotation V for disengagement of the clutch when the said roller has come to engage in the recess 12.

When the suction is greater (meagre charge to the engine) the diaphragm 68 is drawn in towards the right of Fig. 2*. which consequently diminishes the action of the spring 55 and the reverse conditions are met with.

In two different ways there has therefore been introduced into the operation of the distributor G a newrvariable, that is to say the action of the suction materialising from the charging of the engine, in such-a way that the operation Yof the clutch is regulated 'at the same time by two varient conditions, that'is to sav that it must be rapid and no longer reouires such a precisecarrying out of the actions which produce and control its operation.

It is proposed to arrange the control ofi-'the servo-clutch during the changes of thes'peed gear combinations, in such a wav that th"en' gagement of the clutch B is lessened in the neighbourhood of the value corresoonding'to the couple actually transmitted at this moment by the engine to the driven mechanism and that this'engagement is re-established. for example progressively and integrally, when the operation is terminated. l

For this purpose there is made to intervene another distributor H but duringr the changes of the gear speed only. Advantageouslv. this supplementary distributor is arranged ad'acent the distributor G in such a wav that certain of the conduits or passages in which the oil circulates can be made common at least in part. In this wav the distributor H is constantly` branched on to the circuit of the 'oil under 'pressure by a pine 18 connected to the delivery conduit 4 of the pump upstream of the outlet v48 'supplying the distributor G. Also. the distributor H communicates with the discharge pipe 8 through a conduit 18. e l

The slide valve 11 of this' distributor H generally occupies the position shown on Fig. 2, that is to say that utilized apart from the changes of the speed gears. In this case the slide valve 11 closes the outlet 90 for the oil under pressure and frees the passage 18 through which the return of the oil to the reservoir I takes place.

When the slide valve 11 occupies this position, it in no way modifies the automatic opera.- tion of the distributor G as explained above for it prevents the entry of the oil under pressure through the conduit 15 and does not hinder the return of the fluid which leaves the distributor G through the orifice 49, the passage 1B and the discharge pipe 8.

At the moment when the speed changes must be considered, the slide valve 41 of the distributor G has left the position shown on Fig. 2 and has been displaced towards the right in order to open the orifice 49 through lwhich the discharge of the oil takes place and which corresponds tothe engagement of the clutch.

When a change of speed is effected by means of a manual or automatic control which will be explained. hereafter, the clutch B is disengaged through the exclusive intervention of the distributor H and this operation takes place at an instant when the speed of rotation of the engine is certainly higher than .V1l in such a way that the slide .valve 41 of the distributor G is always at the position of lengagement of the clutch, that is to say that the orifice 48 is open.

' In order to operate the slide valve 11 at the re quired moment and in a determined direction,

there must be brought into action the manual or. automatic controlof-the gear box or boxes. For-the examples shown .on the drawings it has been supposed that this control also closes lan electric contact 18 (Fig. 6) by which a coil 19..is connected, during each change of speed. by a, wire 8|! to a source of electricity 8l, for example the storage battery of the vehicle. This coil-19fthen attracts a plunger 82 integral with the slidevalve 83 of a distributor K by which a pipe B4, .proceeding from the suction pipe of the engine, can be put into communication through apipe 8l with a chamber 88 containing a diaphragm 81 or a piston connected by a rod 88 to the slide valve 11 of the distributor H.

A return spring 89 tends to return the slide valve 11 to its initial position* shown on Fig. 2.

At the time of a change of speed gear the coil 19 is excited and instantaneously displaces the slide valve 83 in such a way that the diaphragm 81, under theeffect oi' the suction, is urged towards the right of Fig. 2. It actuates the slide valve 11 the useful part 11* of which opens the outlet 90 oi' the conduit 1li containing the oil under pressure and the useful part 11h of which closes the inlet of the discharge passage 16. The oil under pressure can then pass from the conduit 15 through the chamber of the distributor H, through the orifice 49, through the chamber oi' the distributor G and through the conduit I5 in order at least partially to disengage the clutch B as explained above.

When the change of speed gear is terminated, the contact 18 (Fig. 6) is interrupted and the coil 19 frees the slide valve 83 which interrupts the action of the' suction. The diaphragm 81 as well as the slide valve 11 return to their initial position (Fig. 2) under the action of the return spring 89, in such a way that the outlet 9D of the pressure conduit 1l is closed and that the discharge passage 18 is opened, the return of the oil taking place through the orifice 49. This immediately causes the re-engagement of the clutch. Care is taken to give the useful parts 11n and 11b unequal surfaces in such a way that the pressure of the oil exerts an axial reaction on the slide valve 11 as explained with reference to the slide valve 41. This reaction renders the pressure of the oil variable, as a function of the efi'ect of the suction on the diaphragm 81, and

consequently as a function of this suction itself.

| of the slide valve I1 of the distributor G-. the equilibrium of the slide valve 11 can only take place when the thrust due to the pressure of Athe oil becomes equal to the action exerted by the suction on the diaphragm l1, which amounts to saying that the pressure of the oil varies in the same way as the suction.

Care is taken to dimension the various memof the suction (no charge) is equal to that which assures the complete disengagement, whilst that corresponding to the minimum suction (maximum charge) is zero (complete engagement). Under these conditions, the values of the thrust of the oil on the slide valve 11, therefore those of the pressure of this oil, exactly follow the values of the suction during the carrying out of the changes of speed gear, therefore finally the values of the engine couple, and the clutch is disengaged all the more as the couple transmitted at this instant is weaker.

There has therefore been realised very simply the condition of engagement of the clutch assuring a perfect smoothness of the changes of speed gear, since the engagement of the clutch can never be disproportionate with the couple actually to be transmitted at this instant and this in spite of the fact that this couple can take any value included between zero and the maxlmum couple.

By the dimensions given-to the diaphragm 01 or the like and/or by a more or less intense action given to the spring 09 for the purpose of correction, it is possible to obtain at this moment, according to the particular characteristics it is desired to give to the construction contemplated,-

an engagement which may be exact" or a little higher or again a. little lower than the couple transmitted at the same instant.

It is advantageous for the return to normal operation to be carried out progressively. This can be obtained in various ways.

First 'of all it is-.possible to retard the return of the slide valve l0 of the distributor K to its obturating position by braking, through a small orifice 9|, the outlet of the air contained in the chamber 92 formed in the distributor below this slide valve.

It is also possible to brake the return of the air into the chamber 86 for the diaphragm 01 by a small orifice 93 of regulatable section, for example by a pointed screw 94, which permits a very progressive return of the chamber 05 to atmospheric pressure. This return' is accompanied (suction diminished until it becomes nullliled) by a progressive reduction of the oil pressure which acts in the servo-clutch, and there results therefrom a very progressive engagement of the friction surfaces of the clutch, up to maximum engagement. One therefore returns very progressively from disengagement in proportion to the couple transmitted, to the complete ensagement of the clutch.

The arrangement such as described can be utilised to obtain the operation of the transmission in freewheel by automatic disengagement of the clutch when the driver releases the pedal 95 of the accelerator in such a way that the vehicle is uncoupled from its engine which then rotates at slow-running.

For this purpose there is provided, for example on the dashboard, a switch 96 which, when it is closed by an'action by the driver, branches 14 to the current source Il a contact 01 provided on the accelerator pedal 9|. When the pedal is completely raised, this contact I1 contacts a terminal 0l connected by a wire 0l to the coil 10-of the distributor K which causes the disengagement of the clutch, as explained above, as long as the pedal remains raised, the suction then being a maximum. As soon as the driver lowers the pedal, the energisation of the coll 10 is interrupted by I1-50 and the clutch B is again engaged.' This operation in free wheel is only possible from the moment when the driver has voluuntarily closed the swtich` 95 for when this latter is open the feeding of the coil 'I9 by the wire l! becomes impossible.

The operation of the clutch during the changes of the speed gear can be effected more rapidly and under the best conditions when there is brought into action a synchronisation device which regulates the disengagement of the clutch in such a way that the engagement is made possible as soon as the members 'to be `coupled in the variable speed gear box or boxes have attained substantially equal angular speeds. This intervention corresponds practically to the automatic realisation'of the operation called "double declutching and which some drivers carry out during the changes of the speed gear and more especially during the passage to a lower gear combination. It is known that this operation fconsists, after having separated the members of the speed gear box which give the ratio previously utilised, in accelerating the engine in an endeavour to give it as accurately as possible the speed it will have with the new ratio, which allows, at this instant, the engaging, without dimculty, the members which give this new ratio.

For boxes with friction clutches the diiliculties of engagement are not so considerable as for boxes with engageable gears, but synchronisation is nevertheless advantageous so that the operation can take place as rapidly as possible and to prevent the friction surfaces to be coupled from slipping or causing jerks in the transmission when the clutch B is prematurely engaged.

Such a synchronising device can be constituted as follows and as shown in detail on Fig. 8.

In the neighborhood of the distributor assembly G and H there is made to terminate a shaft |00 driven according to any ratio M by the engine and for example through the intermediary of a belt transmission |0I, This shaft |00 can therefore be that of the lighting dynamo. On the extension of the said shaft |00 is located a shaft |02 connected, by a ratio slightly lower than M and for example 0.98 x M to'the input shaft |I of thespeed gear box or boxes, for example by a worm drive |03 and a flexible connection |04.

One of these shafts, for example |02, carries a screw |05 with rather rapid threads, preferably of triangular section, and of desired hand. The other shaft |00 carries a casing |06, the interior length of which is greater than that of the screw |05 and which is capable of sliding on the shaft |00 and being driven in rotation by this latter. It carries in an aperture in its periphery, a part n giving a drive limited by contact with the threads of the screw |05, for example a ball |01 held forced between these threads by a spring |00. If the two shafts rotate in the direction indicated by the arrows on Fig. 2 and if the thread of the screw |05 is right handed. the device functions as follows. l

It the shaft of the engine A and the input sasso of 'a nut thread with respect to the threads of 5 the screw in such a way that the casing |88 acts as a nut but with limited action due to the spring |08. This actuation makes itmoccupy its extreme position towards the left of Fig. 2, at

which it is stopped. The ball |01 therefore can 10 no longer follow the threads of the screwV and jumps from ione to the other, by clearing their projection and each time compressing the s |00 to-a degree which,-inl this case, is'2% of the speed of theengine. L j A There is located in the casing |88 an exterior groove |08 in which is engaged a fork III, guided. for example, by a rod rI and terminating in a push-bar |I2 located opposite a projection I Il which extends from the slide valve 11 of the dis- 20 tributor H. In the position shown on Figs. l

and 2, this push-bar is not in contact with the projection, I Il.

If anexamination is made of what happens when, for a change of speed gear one to a gg lower combination (changing down) it is seen that in consequence of the change of ratio and of the ,exact disengagement of the clutch as ex- W plained above, the input shaft I I o'f the speed box suddenly takes a greater speed. The engine A cannot follow this variation of speed since'the exactly engaged clutch leaves it with the load `of the couple which it produces at this moment. If matters remained in this state, the dinerence of speed of rotation between the input shaft and the enginetA, therefore between the shafts I |02 and |00 would be maintained until the progressive re-engagement of thev clutch makes .it disappear.

But as soon as this difference of speed has ex- 40 ceeded the value of'2% that ls -to say practically as soon as the shaft |02 turns more quickly than the shaft |00, the ball |81 under the action ofthe threads of the screw |00 drives the cage |08 towards the right of Fig. 2. After which, not being able to go further. it again begins to jump over the threads of the screw |00, while remaining under their inuence. In its movement the oasing draws along the fork |I8 and the push-bar ||2 which positively forces the slide valve 11 50 back towards its position of complete declutching whatever may be at this moment the value of the suction acting on the diaphragm 81 or the like, the power of the spring |08 being at least equal to that oi' the maximum action to be Dro- 55 vided for this suction. y

The clutch B is therefore completely disengaged as soon as the input shaft II has taken up a speed of rotation higher by more than 2% than If the carburetor is only eo that of the engine. slightly open at this moment the engine, freed from any load by this operation, at once accelcrates. All its available vpower is utilized for this acceleration which can consequently be instan'- taneous and thus constitutes a gain of time for es the change of the speed gear. A's soon as the speed has become such that it is now only at '2% below that of the input shaft the screw N0 and the casing |00 have the same speed of rotation and the casing returns to the position shown l on Fig. 2 for which its action on 'the distributor H ceases. The clutch is immediately re-engaged at the value of the couple transmitted (suction only) 4then progressively in entirety. On the commencement of the engagement it can be said that the disengagement of the friction parts is necessarily accurate since it is precisely the difference of speed of rotation of the friction surfaces which produces it and makes it cease.

In order to be sure thatv the time required by the operation shall be the minimum, it is sumcient to facilitate the "accelerationof the engine during the disengagement of the clutch. For this, there can be arranged, in the neighbourhood of the controlling arm I II (Fig. l) of the throttle of the carburetor or in any other favourable position of the rod which controls this arm, a lever ||l coaxial to the arm Ill and which is adapted to act, for example by an adjustable projection I I8, on the arm I I4 in order to increase the opening of the throttle. 'I'he lever IIB is connected,

for' movement by the fork ||2 for example by being connected by arod II1 to the guide rod ||I of 'this latter.

0f course this temporary` opening of the throttle of the carburetor during synchronisation could be obtained by other means than those indicated above.

In the foregoing it has been supposed that the distributor K (of the suction) comes into action for each change of the speed gear, whether it be rising or falling, whilst the synchroniser |08 only comes into action for passages to a lower combination. On Fig. 7 there has been shown an arrangement for which the effect of the suction, regulated by the distributor K, only acts for the lrising changes of the speeds whilst the control |06 but this time without the.iinterventlon of the suction at the time of engagement.

'I'he control mechanism of the speed gear box and which will be described more explicitly hereafter, produces by its displacements in the direction for which one passes to a higher speed combination, the closing of the contacts`18 and 18* which conduct the current through the wire to the coil "of the distributor K. For all the rising changes there will therefore be obtained the operation of the slide valve 11 of the distributor K with intervention of the suction as explained above.

l When thev control mechanism is acted upon in order to pass to a lower speed combination there is obtained the closing of the contacts 18 and lll'which, by a wire 801, conduct the current to an interrupter |I8. This latter, which is normally open, can be closed by the rod'I II of the synchroniser |08 as soon as, in consequence of a falling speed gear change, the shaft |02 turns more than 2% more quickly than the shaft |00. At this moment the interrupter' I8 energises a coil 181 in which is accommodated a plunger 8 2! which carries a push-bar I I8 with guiding rod |20 and which is capable of forcing the projection I3 of the slide valve 11 of the distributor H towards aposition for which the disengagement of the clutch B is obtained. This displacement is made i7 possible owing to the lost-motion connection f |2| provided between the slide valve 11 and the rod 3l controlled by the eii'ect of the suction.

By the closing of the contact 131 the coil 131 is energised and instantaneously attracts the plunger 321 which forces the slide valve 11 towards its declutching position. At this moment there comes into action the synchroniser |46 which maintains the contact I I3 closed as long as the shafts and |02 do not turn in synchronism and which opens the contact ||8 by displacement of the casing IIIB and of the rod towards the left of Fig. 7 as soon as synchronism is attained, as explained above. The energisation of the coil ceases and the plunger 821 returns to its inactive position under the action of its return spring. The slide valve 11 of the distributor H follows this movement, by nbeing pressed by its spring B9, which permits the engagement of the clutch B.

Moreover, it is possible, if one is satlsiled with an approximate synchronisation, to simplify the mechanism a great deal. The wire 301 is then connected directly to the winding 191, entirely eliminating the contact ||3 and the synchroniser |04.

In this way the current sent by the contact 18|` arrives directly to actuate the plunger 821 every time a falling speed gear change takes place and thus causes the complete disengagement of the clutch. In this case it is advantageous to regulate the period during which the disengagement of the clutch takes place and for this purpose there can be provided on a part integral in movement withy the plunger 321, for example on its guide rod |20, a dash-pot |22 whose action is regulatable by the needle valve |23 and which brakes the return movement of the plunger 321 and in consequence of the slide return springs;

. for each gear box D or It is alsov expedient'to lobserve that one could -n very well omit V the distributor K and permanently connect the chamber |I B having the diaphragm 81 or the like by conduit B5 (Fig. 4) tothe-suction'pipingof the engine, while-regulating, how-v ever, the various controlmembers'so that the engagement always mair'itains an'appreciable security with respectto 'the couple transmitted" l' by the-clutch. In this case the engagementen the clutch would be permanently variable as afunctionV of the engine couple and would therefore be constantly regulated las at the time of changes of speed gearf which does not `present any disadvantage'in itself so long as the security of engagement is suillcient. But undue wear of thecltuch abutment may result thereiromy'lf special precautions arenot taken with ...afiview to its proper preservation 'andparticularly regarding its lubrication.' *z y 1 There has been described above. iii-'detail andj .by way of example :archange-speed mechanism with a reversing device C and two "planetary gear A Vboxes'D and E with oil servo-motors 3|-34 separate distributors "D1 and E1.

and

E is obtained when the sliding plate 21 is made integral by its conical rim 28* with the planetary gear 23', which is obtained when the pressure does not act in the servo-motor 3|-34 of this box, and thatthe drive takes place at a reduced speed when the said plate is immobilised by the braking ofthe conical rim 23" on a fixed rim 30 and for this purpose the pressure must act inthe said servomotor 3|-34.

Under these condtions and assuming that the lower gear of the box D gives a ratio lower than that of the lower gear of the box E, the four speeds for the assembly are obtained in the following manner.

First speed: Box D under pressurebox E under pressure.

Second speed: Box D under pressurbox E in discharge.

'I'hird speed: Box D in discharge-box E under pressure.

Fourth speed: Box D in discharge-box E in discharge.

The suitable distribution of the pressures or discharges is obtained by an appropriate operation of the distributors D1 and E1 the slide valves of which are connected respectively by remote controis, for example flexible members |32 and |33, to a control device located within reach of the drivers hand and for example on the steering column |331 or on the dashboard.

The details of a control device of this kind are clearly shown on Fig. 6. It comprises a knob |34 the axle |35 of which is capable of sliding and oi' turningin its support |36 and tovwhich the driver can give four active positions I, II,

"LII and IV arranged for example as is standard forrautomobiles. In the case considered above for 'the distribution of the`..pressures, the free extremity ofthe flexible member |32 of the distributar D1 of the boxv Disengagedin a guide |31 in such away that it' can slide in the said guide' parallel'fto Athe axle |35 ofthe knob |34 and this free extremity. is connected to a fork -d |33.' engaged in a'peripheral groove' |39 of the Yaide |35. As a result thereof when "the knob |34 is acted upon by pull or push the vdriving of the '..if flexible vmember 132Jand ofA the slide valve D1 corresponds The nexible member m 'ofthe distribuer E1V is connected to a ringer |40. keyed onk the axle |35 and which is advantageously guided by -a gate 4| commonly used in automobiles in such a way that the useful positions of the axle |35 can be easily determined in the course of the operations of the knob |34. When this latter is displaced angularly in one direction or the other there'is driven at the same time the ilex- -ible me'lnber |33 and with it the distributor El.

It will easily be proved that by placing the knob |34 successively in the four useful positions I. IIl III and IV` there is obtained the correct distribution of the pressures and discharges in the assemblyoi' the two boxes D and E.

The control member |34 can be given the form of a knob 0n account o! the very small efforts necessary for the displacement of the slide valves -preferably balancedof the distributors D`- and E1. There is advantageously provided on the knob |34 a projection which constitutes an indicator for the driver as to the exactposition given to the knob and that even in the dark, to avoid any wrong operation.

0n the axle |35 of the knob |34 there is also 19 mounted a cam |42 which can act on an insulating member |48 carried by an insulated metallic blade |44 connected to the source of electricity 8|. This blade |44 forms part of the switch 18 connected by the wire 80 to the coil 19 or the distributor K (Fig. 2). The member |48 has been given suillcient dimensions so that the cam remains in contact therewith during the axial or angular displacements of the axle |85 but that this contact ceases as soon as the knob occupies any 'one of its useful positions. It results therefrom that the coil 18 of the distributor K is only energised during the operations of the knob |84 to cause a change of the speed gear combinations but ceases as soon as these operatons are terminated, which corresponds in full to the operation indicated for the distributor K.

For this purpose, as shown in Fig. 4, the slide valve 41 can be influenced by 'a supplementary spring 55 acting in the same direction as the spring and the power of which can be modified at will by a lever 56 remotely-controlled by the driver with the aid of a flexible member 51 and a draw knob 58 for example.

In the case where it is desired to be able to modify in this way only the speeds of rotation V1 and V2 but not the speed of rotation V1, the spring 55 is made to act on a lever 59 articulated on the one hand to the slide valve 41 and on the other hand to a rod 60 which, by a cranked lever 6|, acts on the bolt 53 in order to apply to it a fraction of the action of the spring 55. It is thus possible to increase, by equal amounts for example, the action R of the spring 5| and the action Y of the bolt 53.

-The diagram of Fig. 3 shows the result obtained. It is supposed that by the intervention of the spring 55 the action R of the spring 5| has been transferred to R1 and that of the bolt 53 from 03F to CSF. 'Ihe point corresponding to the commencement of the engagement of the clutch is then transferred to C2 for the speed of rotation V2* to the same distance under the horizontal R1 as W was under the horizontal R. The point corresponding to the completion of the engagement is transferred to C at the intersection of the horizontal R1 with the parabola X for a speed of rotation V11.

The action of the bolt 53 having been increased, there must be considered for the action of the forces a new parabola Xb which intersects the horizontal R1 at Fia. It is discovered that the speed of rotation V3 for declutching has not been modified. The points of the commencement (Vz) and of the completion of the engagement (V111) at the time of starting have thus. been displaced without modifying the point of down which is rational in order not to reduce the utilisation of the engine at low speeds of rotation.

If it had been desired also to modify the point of disengagement (V3) it would have been suilicient to change the distribution of the action of the spring 55 on the slide valve 41 and on the bolt 58, for example by adopting a lever 59 with unequal arms. This would be indicated for example in the case where the carburetor of the engine 'comprises a starter device facilitating starting from cold, but which modifies, rather substantially, the slow-running speed oi' the engine by raising its speed. By combining the control of the starter" with the control 51 of the spring 55 it is possible to cause to vary the condition or conditions of engagement and/or of disengagement (V3) at the time of slowingdisengagement in dependence as the slow-running condition of the engine varies.

'Ihe action of the suction acting permanently as engagement reducer when the transmitted couple diminishes is very advantageous when it exerts itself on the slide valve of a simple distributor such as those designated by G and H on Figs. 1, 2 and 4, but this action is not limited to this mode o! operation.

Fig. 5 shows an arrangement which permits of obtaining the result to which reference has just been made, that is to say the elimination of the distributor H and of its controlling members such as K and 181. In this case the clutch B is operated by an arm |24 keyed on the shaft I2 carrying the ordinary pedal |26. On this arm there is made to act, through the intermediary of a lost motion device |21, a rod |28 controlled by two servo-motors |29 and |80 one of which (|29) functions in 4the manner of the oil servo-'clutch |4|1 of Figs. l and 2 and is connected for this purpose by a conduit i5 to the distributor G. The other servo-motor (|38) oi.' larger dimensions, operates by suction by being connected by the pipe |3| to the suction conduit of the engine. It is mounted for example in tandem with this latter, in order to assure the disengagement of the clutch B. The surface of the suction piston is calculated, with respect to the effort necessaryv for the operation of the clutch, like that of the diaphragm 81 of Figs. l, 2 and 4, account being taken of the reaction of the oil acting in the servo-motor |28.

For the example according to Fig. 5 the oil servomotor |28 is controlled only by the distributor G in dependence upon the centrifugal governor 4| in such a way that the servo-clutch only comes into action for the starting and slowing down of the vehicle. Of course this assembly could be completed by a distributor H functioning as explained with reference to Figs. l, 2 and 4 or Fig. 7.

The suction servo-motor |38 can remain in permanent connection with the suction pipe of the engine and in this case, as its action tends todisengage the clutch when the suction increases, the engagement constantly follows the variations of the couple transmitted and itis advantageous to make special arrangements with regard to the clutch abutment;4 that is to say that the result is the same as that obtained by the arrangement according to Fig. 4 when a distributor K is not utilised for the suction. There can also be provided in the pipe |3I, located between the servo-motor IlilI and the suction pipe of the engine, a distributor similar to that designed by K on Figs. 1 and 2 and there is then again found the same result as that obtained by the complete device shown on these figures.

It should be observed that the suction can be influenced not only by the engine couple but also by the variations of the atmospheric pressure (altitude, bad weather, etc.). These influences are not, however, sufficiently important to be able to disturb the operation of the devices described above except in quite exceptional circumstances.

It should not be thought that the clutch controls which have just been described under various forms, are only applicable to planetary gear boxes with frictional engagement, particularly that described in detail with reference to Fig. 1. It can also be utilised for any other gear box,

- for example with sliding gears or with coupling by dog-clutches.

casas 'This follows in itsel! as regards the startings and slowing-down of the vehicle, the gear box not being concerned at these instants. But this is true also for the speed gear changes. with the sole condition that care is taken during these operations. to supply with electricity the coil I3 of the distributor K and/or the coil `131 of the arrangement according to Fig. 7.

The device described can then be utilised without any modification. In eiIect. at the moment oi' a speed change with a gear box, the driver releases the accelerator pedal in order to change speed. This action carries the suction to its maximum value, and instantaneouslythe complete disengagement of the clutch takes place.

But in the case considered, as the driver is always compelled to release the accelerator, partial disengagements become superfluous and the electromagnet 19--32 can be made to act directly on the slide valve 11 and the suction apparatus 33 be eliminated, this electromagnet being energised and explained by the contact 13 associated with the operating member of the speed change. In this particular case the slide valve of the distributor H must no longer be of diilerent area since the pressure of the oil is utilised entirely for the complete disengagement or isv omitted in order to obtain normal engagement.

Inorder to obtain the particular operation of the device shown in plan on Fig. 'lier which there is provided a distributor K set apart for the control of the clutch B during the changing up ofl the speeds and a special coil 191 for this control during the changing` down of the speeds, there must be provided for the knob |34 a more complex movement between these useful positions I, II, III and IV. In this case the knob |34 is always connected to the sliding axle |35 on which is engaged by a long keyway a sleeve |45 which therefore turns with the said axle but is prevented from moving axially by a ilxed part |43. This sleeve |45 carries the linger |40, to which is connected the flexible member |33 of the distributor E1, as well as the cam |42 which controls the switch 13. This switch is connected by a wire |41 to one conducting and insulated extremity of an oscillating lever |43 articulated at its centre to a rod |49 connectedto the flexible member |32 of the distributor D1 and axially guided by a xed part |50. On both sides of the conducting extremity and at a certain distance from this latter there are provided arms and |52 keyed on the rod |49. The conducting extremities of these arms carry respectively the terminals 13 and 131 connected respectively by the wires 30 and 301 to the coils 13 and 131 the function of which has been explained above. The other extremity of the lever |43 is engaged with a pin |53 mounted on the axle |35. The slots oi.' the gate 4| are arranged obliquely in such a way as to compel the knob |34 'to perform oblique and axial movements so as to pass from one useful position to another. This guiding is such that for changing up, that is to say from the positions I to` II, II to III, Irl to IV, the knob |34 and the axle |35 are always moved in the same direction from left to right oi' Fig. 7. For each of these movements there is first of all obtained a sliding of the axle |35 and an inclination of the lever |43 until its conducting extremity comes into contact with the terminal |5| to leed this latter and it is only after this contact that the rod |49 and the flexible member |32 are driven through the intermediary of the arm |5| to act on the distributor D1. The angular movement of the knob |34 causes, as for the example according to Fig. 6, the control of the nexible member |33 and ci the slide valve E1.

On the other hand. for changing down, the movements IV-III, III-II, II-I of the knob |34 all Atake place in opposite direction and in this case'the conducting extremity of the lever |43 comes each time into contact with the terminal 131, which energises the coil 191 whilst the rod |49 and the ilexible member |32 are moved axially through the intermediary of the lever |43 and of the arm |52.

When the action on the knob |34 ceases the lever |43 returns to its inactive middle position, which interrupts the energising of the coil 13 or 131. But, moreover, the distribution of the current is regulated through the intermediaryof the cam |42 and of the interrupter 131 which accompany the speed gear changes. The current is always interrupted when these latter are terminated and when the knob |34 has arrived at one of its positions of normal use.

Moreover care is taken to give the slide valve of the distributor D1 which controls the simple gear box D such a form that the supplemental movement which is thus imparted thereto between the positions I-II and III-IV of the control member |35 is without eiect on the distribution, this latter only passingfrom supply under pressure to discharge between the points II and HI and inversely.

The invention is in no way limited to the special planetary gear boxes D and E shown by way of example but is also applicable to gear boxes of any kind such as the sliding gear box, of a standard type, shown on Fig. 8.

Direct drive is obtained by the engagement of the sliding dogs |53 of a ring |54, sliding with a long keyway on the shaft |55 which extends from the gear box to drive the wheels of the vehicle, with sliding dogs |53 integral with the input shaft of the box. The third speed is obtained when the sliding dogs |51 are engaged with the sliding dogs |53 carried by a pinion |59 mounted loosely on the shaft |55. The second and rst speed are respectively obtained by the meshing of the slidingwheels |60 and |3| engaged on the intermediate shaft |32 with the wheels |33 or |34 integral with the intermediate shaft |35.

These Vmovements are respectively obtained by the axial sliding of the forks |33 for the speeds III and IV and |31 for the speeds I and II.

It is proposed to produce the movement of these forks by the hydraulic device already described and that under the control of an operating member, such as a hand lever |341, provided within reach of the hand of the driver. For this purpose the movement of each fork is subjected by an appropriate small servo-motor to the movement imposed by the driver on the distributor of the servo-motor concerned.

The fork |31 is controlled for example by the small servo-motor Dl the piston of which is connected to this fork by a rod |39.

`The fork |33 is controlled by a small servomotor similar to that ,designated by D*L and by a rod |33.

In order to control a distributor D1* for the servo-motor Dn and that of the second servomotor recourse is had to an operating member constituted, for example, by the hand lever |341 and which controls the two distributors through the intermediary of two separate controls such as ilexible members |32 and |33. On the side 'memben of the hand lever these flexible members, suitably guided, respectively present driving notches |32 and |33 in each of which the hand lever |341, capable of sliding on its axis and oi' turning around this latter, can be engaged in order to assure-the driving of the corresponding flexible When the free extremity of the hand lever occupies on'e of its active positions I, II, III and IV, the distributors of the servo-motors such as De are brought to a position for which there is obtained the bringing into action of the new speed combination.

lThe extremity of each of the flexible members |32 or |33 is not directly attached to the slide valve of the corresponding distributor but actually through the intermediary of a leverl |1| to which there is articulated, at an intermediate point, a rigid rod |12 which prolongs the said flexible member. A ball |13, influenced by a spring and co-operating with notches provided in the rod |12, holds this latter in each of its exact useful positions to which it is brought by the hand-lever |341. One 4extremity of the lever 1| is articulated to the spindle |14 oi' the slide valve and the other is engaged, through the intermediary for example of an elongated eye |15 on a pin carried by the rod (|89) of the correspending servo-motor. In this way the distributor of each servo-motor is compelled to follow, with an exact amplitude, the displacements imposed thereon by the control member |341 while being also subjected to the influence of the reactions of the piston of the servo-motor in' the course of its operation.

The slide valve of each distributor comprises two obturating parts |18 and |11 suillcently spaced apart so that the outlet of the circuit conducting the oil under pressure, is never obturated by one or the other of these obturating parts. At the middle position of the slide valve, it obturates, however, at the same time the two passages |18 and |19 connecting the distributor to the two covers of the cylinder of the servomotor (DB). The two extremities of the body of the distributor (D1) are constantly in communication with the discharge conduit 31.

It is assumed that the driver, by acting on the hand lever |341, has moved the lever |1| by the flexible member |32 in such a way that its upper extremity comes to`occupy the position a. In this case the slide valve of the distributor D1'l is driven towards the left of Fig. 8 and the oil under pressure passes through the conduit 35, the middle space of the distributor and the passage |18 in order to act on the right-hand face of the piston of the servo-motor Dl. The other face of the said piston is subjected to the discharge pressure through the passage |19, the right-hand space of the distributor and the conduit 31. The piston is set into movement and drives not only the fork |61 but also the lever |1| which pivots around the extremity of the rod |12. As a result thereof the slide valve of the distributor is moved towards the right of Fig. 8.

If the point of articulation of the rod |12 to the lever |1| is located at the middle of this latter, the rmovement of the piston is equal but in the opposite direction to that of the slide valve of the distributor but ii', as shown on Fig. 8, the point of connection is located nearer to the distributor, the amplitude of the displacement of the slide valve will be less than that of the piston.

iConsequentlyI when the piston arrives at its position b, the lever has restored, for example, the slide valve to its neutral position c and the servo-motor stops. At this moment the speed gear change has been effected. It results from the foregoing that the driver decides and causes the operation of the slide valve of the distributor in a determined direction, but that he need not intervene at the end of the operation of the speed gear change to restore the distributor to its initial neutral position, this action being performed by the servo-motor itself when the operation is actually finished.

It could easily be provided that bythe action of the hand lever |341 or the like on the two distributors it is possible to obtain at will the substitution of the desired speed change for that it is desired to abandon, and as the efforts to be exerted on the slide valves of the distributors are very slight, the hand lever |341 or the like can have very reduced dimensions so that it can be located in any desired position and which is easily accessible to the driver.

The invention can also be applied in the case where it is desired that the control is entirely automatic and regulates not only the operation of the clutch device B but also that of the speed gear box or boxes whatever may be the constitution of these latter. It has been shown above that for the operation of the speed change (with the exception of the reversing mechanism) it is sufficient in all cases to distribute in the servomotor associated with each of the boxes a iiuid (oil) under pressure` or to eliminate, at least in part, the effect of this pressure in order to obtain the desired result. For the preceding examples there are interposed, for this purpose, distributors the slide valves of which are controlled from a distance and without diiiiculty by the driver in such a way as thus to obtain a semiautomatic control of the speed change.

It is now proposed to control the distribution of the fluids under pressure or in discharge by entirely automatic means. For this purpose the slide valves of the distributors vD1 and E1 of the preceding examples can be combined into a single. part (Fig. 9) in which, in the case where it is a question of the operation of two coupled gear boxes of the kind of those shown on Fig. 1, four series of peripheral channels are provided, the forms of which are clearly visible on Figs. 9|, 9b, 9 and 9d. spaced over a part of the length of the slide valve |80 in such a way that they can be brought successively opposite the conduits, in which is located the oil under pressure or in discharge, by an axial movement of the slide valve |80.

The useful positions of the slide valve |80 are determined by a retaining device constituted for example by a ball |8l, influenced by a spring and co-operating with notches |82 provided in the slide valve.

Besides the distributor N which controls automatically and for example two distinct gear boxes D and E as for the preceding embodiments, it should be understood that there is lnterposed a distributor G for the automatic control yof the clutch B during starting and slowingdown and a distributor H for the automatic control of the same clutch during the changes of the speed gear combinations.

As for the example shown on Figs. 1 and 2, the oil under pressure is supplied through the conduit 4 and is brought, on the one hand, to the distributor G by the outlet 48 and on the other hand to the distributor N by the conduit 35. The discharge of the oil, proceeding from the distributor G takes place through the discharge These channels are i pipe l and that proceeding from the distributor N through the pipe 8l. The distributor N is connected to the servo-motors of the gear boxes D and E respectively through the conduits 88 and 88 and the distributor G is connected to the clutch B through the conduit i8.

In order to control the slide valve |80 of the distributor N it is possible to utilise one or several functional factors of the engine or of the vehicle for example the speed of the driving or driven shaft obtained from a centrifugal gov# ernor driven by this shaft, the load on the engine which would then be taken on from a dynamometer or by 'a deformable member (diaphragm) or movable member (piston) on which the suction of the engine acts, or any other appropriate functional factor.

For the example shown on Fig. 9 it has been `assumed that this distributor N is controlled by a governor driven by the engine shaft. This governor could be distinctfrom that (Il) which `acts on the distributor of the clutch orit can be combined with this latter. In this case it is` necessary suitably to distribute the action of this single governor Il to the slide valve I1 of the distributor G and to the slide valve'fl80 of the distributor N so that the interventions of these two distributors cannot mutually interfere, that is to say that the slide valve l1 only occupies certain useful positions for the speeds of rotation W (disengagement) Vl (engagement) or even Vl (declutching) of the engine which only aifect the clutch B during the startings and slowing-down of the vehicle whilst the slide valve |80 comes into action advantageously according to the speed of rotation Vi only, for which the clutch B is completely engaged.

This distribution of the action of the governor Il could be obtained by mechanical means, for example by a swing bar transferring on to the distributors concerned the effect of the governor 8|. However in this case the governor must be given a greater power or stroke, which. may complicate the construction.

- Recourse may also be had, as shown on Fig. 9, in a proportioning distributor P, appointed to assure, in an accessory circuit, an oil pressure vwhich follows the variations of the centrifugal force of the governor. It is the oil of this circuit at centrifugal pressure which is then distributed in such a way as to act on the movable parts of the various distributors in the same way as sasso the governor would directly, for example through i the intermediary of the swing-bars.

For this the distributor P is arranged like the distributor H of Fig. 2; it has an inlet |84 for oilunder pressuresupplied through the delivery conduit I of the pump 2, an oil outlet |85, the slide valve |88 closing these two passages at its middle position by its obturating parts |88n and |83". The pipe |88 is never covered by these obturating parts. The governor acts directly on the slide valve |88 and in order to create the reaction of the oil which renders its pressure proportional to the action X of the governor an opening |90 `is bored for example in the ob` turating part |88. In this way there is utilised, in order to create the thrust action of the oil, no

longer the difference of section of the two ob- This mechanism creates an axial thrust sim- 26 ilar to that which has already been explaine at the time of the description of a slide valve with obturating parts of different diameter and this thrust always being equal to the action of the governor Il, the oil pressure from the distributing circuit |88 follows the variations of the centrifugal force. This circuit |86 is appointed to distribute this pressure on the end of the ande valves @i the distrital-.ors G and N in such a way that these latter receive, by this centrifugal pressure, actions which are proportional to those they received directly or indirectly from the governor as for the preceding examples. 'I'he proportion is regulated by the ratlos of the diameters of the slide valves 41 and |88 to that of the slide valve |88.

For the distributor |80, appointed to control the speed changes, it is necessary to oppose to the action of the oil at centrifugal pressure" supplied by the by-pass |88 a variable resistance, particularly by causing to act on a spindle |9| of the slide valve an opposing spring L89 the stress of which can be modified, at will, by the driver through the intermediary of a remote control such as a lever |92 on which the driver can act through the intermediary of a rod |98.

` The spring |88 could act directly on the stem |9| of the slide valve. But being given the rather considerable stroke of this part, its length would have to be very great if it is desired that this later shall not have a great influence on its power. y

It is preferable, in order to diminish the extension of the spring |89 and, in consequence, its length, to make it act on a lever |25. articulated to a fixed point and receiving the action of the spring on a relatively small lever arm in order to transmit it to the stem |9| by a lever arm which is clearly larger.

For the automatic control the ball |8| does not play only the part of a simple holding device.' 'I'he retaining force which it exerts must advantageously be variable either with the thrust of the oil acting on the slide valve |80, or with that of the opposing spring |89. For this purpose there is made to act on the spring |94, which determines the eifort transmitted by this ball, a' small piston |98 located in a conduit |96 branched on the by-pass |88 through which the oil under pressure is brought to the distributor N.I The device thus constituted operates as follows.' When the governor 4|, driven by the engine, develops a centrifugal force corresponding to the speed of rotation V2 of the engine, the slide valve |88 has come to occupy a position for which the outlet |88 for the oil under pressure is uncovered and the pressure acts through the middle space of the distributor, through the passage |86 and through the by passes |81 and |88, on the slide valves 41 and |80 of the distributors G and N. By the action of the forces acting on the slide valve |88 this pressure increases, as stated above, with the momentary value of the centrifugal force. Between the speeds of rotation W and V1 of the engine, as explained at the beginning, the engagement of the clutch takes place whilst the -slide 'valve |80 of the distributor N always occupies the position, shown on Fig. 9 for which the engagement of the first speed is obtained. As indicated with reference to the operation of the gear boxes D and E shown on Fig. l, it has been supposed that in this case the pressure must act at the same time in the two boxes and in order to do this the conduit 88 must communicate with the pipes 88 and 89 supplying respectively the -ferent .positions for the different sulating portions the meiiilerfli8',l isfprovided with sasso c 27 servo-motors of the gear boxes D and E asindi-K cated on Fig. 9*. When the speed of rotation of the engine continues to increase, the pressure oi' the oil in the by-passes |81 and |88 increases in consequence. This does not modify the position of the slide valve 81 of the distributor G but when the pressure of the oil in the distributor N has become sumcient to overcome the retaining eiort o1' the ball |8| and of the spring |88 there is obtained a rapid movement of the slide valve |80 towards its second active position (Fig. 9b) for which the conduit 88 of the box D remains under pressure and the conduit 88 o! the box E is in discharge, which corresponds to the bringing into action of the second speed. When the speed of rotation of the engine, which has undergone an increase after slowing down by reason of the change of the speed gear, increases still further, the slide valve |80 is broughtto its "3rd speed" position for which the conduit 88 of the box D is in discharge and the conduit 88 of the box E under pressure (Fig. 9c). Finally the engagement of the "4th speed is obtained when the slide valve |80 is at its extreme position for which the two conduits 88 and 88 are put' into discharge (Fig. 9d). valve |80 in the opposite direction takes place at the time of the lowering of the speed of rotation. of the engine, through the action of the spring |88.

It should be noted that the control of the gear box, by a distributor such as N, can also be applied in the case of a semi-automatic control by the driver who then displaces by hand and this only by way of emergency control, the slide valve |88 in order to bring it to the desired characteristic position. The control of the clutch B during the speed changes takes place exactly as for the vpreceding examples by the distributor H the slide valve 11 of which can be arranged according to anv on. of the methods already described, the devices functioninggwithithe aid of the-il at centrifugal pressure ,necessitating no `modification of the distributor H.A v, y

For instance, as shown in Fig. 9,- the -slide valves G--and H and mechanismK of Fig. 1 are used. It is obvious .that'the/lever ,|28 controlling the position of slide valve |80-occupies four-difsbeed ratios` The end ofY lever |28 is insulatedV and is provided with acontact sliding over the surface of an opposed contact member 18x. The/contact on the The movement of the slide proportionally to the stress ofthe spring |88, according to the same principle as that which has been adopted to obtain the centrifugal pressure.

Such a construction is shown on Fig. 10 for vduit 208 to the space |88 which is located at the right of the slide valve |80 of the distributor N. A discharge conduit 20| also proceeds from the distributor Q to open into the general discharge pipe. The lack of equilibrium of the slide valve |81 is assured-for example by providing a passage |81 in the obturating part Ille. By .the iniluence of the spring |88 and by the thrust of the oil which acts in -the opposite direction on the slide valve |81, the pressure of the oil supplied through the conduit 200 becomes proportional to this thrust and this pressure in this case acts as opposing force on the slide valve |80 against the pressure of oil delivered by the ddis-- tributor P and by the by-pass |88. This pressure can then be distributed to various apparatus. if necessary, as has been explained forthe centrifugal pressur oil circuit. l

'I'he reduction of the force necessary for the operation of the lever |82 in order to modify, ii necessary, the stress of the spring |88 results in this case from two facts. The slide valve |91 of the distributor Q has a stroke considerably less than that of the slide valve |80 of the distributor N in such a way that the work to be produced is already less for an equal force. Moreover this force can, itself, be very reduced if there is `given to the diameter of the slide valve |81 a value clearly lower than that of the slide valve |88. Y l v Up tolthe present there have -been shown examples-of means by which an oil pressure could follow the ,variations of a determined'functional factor, for example the centrifugal force VX of a governor Aas regards the distributor P, the suction asA regards the distributor H or the power ofV a spring, as regards thedistributor Q. Vn Fig. 10 the distributors P and Q received respectively-the actions of the centrifugal force X .Hand of'the spring |88 and transformed them end of lever |28 is connected to line 80, while contact 18x is connected to a source of current 8|. Contact ...menber 18 has insulating portions tion. oi'valve |80 corresponding to the enga8e` ment of some gear ratio, andbetweeri` these inconducting portlons.-l l A Itis' evident thatfa's the" member' |88l moves fromv the position corresponding to one gear ratio to. that corresponding to thenext, contact will be 'made between they end'of lever |28 and the member 18x, and 'current will therefore ilow through wirel't'o the mechanism K. This will cause-at each change from one gear ratio to another the disengagement and re-engagement of the clutch in the same manner as is explained for Fig. 2.

The operation of the rod |88 requires a rather considerable effort which can be greatly reduced by causing to act on the slide valve |88 of the distributor N an oil pressure which varies- Vinto an oil pressureplpportional to these actions,

pr,essures--acting respectively on .theA slide valve |80, by thrust on its two bases.

Fig. 1l shows an arrangement for which the .distributors P and Q are combined into a single distributor T, the slide valve 280 of this latter being influenced in opposition by the two actions onnosite the contact on. lever |28 for each posi-l.-

-livery conduit 4 of the pump 2. When the slide valve 288 is in equilibrium under the action of the two aforesaid forces, its two obturating parts respectively close the two exhaust conduits |88* and 200* opening into the distributor N in such a' way as to be able to act, when they are supplied, on the ends of the slide valve of this distributor N (Fig. 10)

When the `centrifugal force is preponderant, it displaces the slide valve 280 of the distributor T, which uncovers the conduit |88* and the oil under pressure forces the slide valve 80 of the distributor N towards the right as for the arrangement according to Fig. l0. On the other hand. if the spring |88 becomes preponderant,

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