The present refers to a new , simple , Automatic Hydrostatic Continuous Variable Transmission (C.V.T.) of a closet circuit , which being driven by Inertia attain the motion of the vehicle with the most suitable transm ission relation , so that its engine to be continuously operating at the area of the minimum consumption .

The achievement of the said goal has become possible with the design of a new vane pump- motor, of sl iding vanes , of f ixed eccentricity , the volume variation of which is being achieved with the continuous shift of the one side of it . This pump, in serial combination with another similar pump which , in this case , operates as an hydrostatic motor , achieve through a very sim¬ ple automatic inertial mechanism the smooth, noiseless and continuous changing from a short 1st to a final speed beyond overdrive. The said Transm ission is , at the same time , clutch and power brake , whi le at its more complex edition it also includes a self-controlled hydrostatic differential .

At the level of the previous technique there exists only one mechanical C.V.T automatic gear box , SELECTA by FIAT , which is a development of the old Vaπomatic of the Dutch DAF . The said box has two variable diameter pul- leys which are driven by a steel belt . a planetary gear system , two hydrau¬ lic cyl inders , one common differential and a compl icated complex of electro- hydraulic valves which receive their instructions from a m icrocomputer , with sensors which provide informations for the position of the throttle , the po¬ sition of the belt , the position of the selection lever and the revolutions of the engine . The said boxes have a lim ited abi l ity of transferred torque due to the sliding of the belt and are being placed only to smal l vehicles .

The hydrostatic transmission boxes , on the other hand , which exist today use variable eccentricity vane pumps with a small area of f luctuation of their supply being achieved with the alteration of their eccentricity . This has as a result a great loss of power because at the interval positions of the rotor a part of the oi l returns to the low pressure area without producing any power.

The hydrostatic systems with the axial piston pumps of variable displacement may not provide a great range of of suppl ies with a smal l size of pumps and, furthermore, they require Clutch and Differential.

Al l the transm issions of the previous technique wich have been mentioned, are accompanied by compl icated control units, which interfere with the automa¬ tion circuit, increasing the construction cost while they decrease the eff icien¬ cy end the effectivnes of the system.

The invention belongs to the new technique of hydrostatic transm ission of motion, yet without the disadvantages of the previous boxes of said category.

The invention is an automatic inertial continuous variable transm ission , in which the transm ission of motion is being carried out by a pair of reversible vane pumps of a new design, of f ixed eccentric ity and variable cubage, of the type "moving side" connected in series in a closed hydrostatic circuit, where the driving pump is directly connected with the engine ^' s f ly wheel, with no reverse gear box and clutch and through the hydraulic fluid , transfers its motion to the pump (B) which operates as a hydrostatic motor as wel l, tur- ning the wheel. The continuous l inear changing of speeds is being achived with the continuous displacement of the moving side of the pump (A) which is be¬ ing accompanied by the continuous reverse displacement of the moving side of motor (B), because the circuit is closed, the quantity of whole f luid is con¬ stant and the f luids are concidered to be practicaly incompressible. When the volume of the pump is being decreased by dV the volume of the hydrostatic motor is being increased by dV, yet as the ratio of volumes is in inverse ratio with the rounds , and in direct ratio with the torques, any alteration of the ratio of volumes is being expressed w ith the respective alteration of the ratio of rounds and torques and since the moving side may receive inf inite positions (between two l i m its) then and the ratios of the box w i l l be inf init .

The said way of transm ission is more advantageous of the one with pul leys and belt, as it has no losses due to the sl iding of the belt, starts i m media¬ tely and offers, practicaly instant torque w ith stable power at a w ide range of speeds.

For the movements of the side of the driving pump, there operates a very si mple automatic inertial mechanism which, with a wide pitch screw at the position of the axis of the pump, the formation of the rotors center hole to equivalent nut and two hel ical springs (7)&( 15), which tends to restor the syst- em at the position of the maxi mum volume of the pump (A), w-hile it reads through the pressure being developed, continuously among the vanes (a)and(b) FIG. 6b of the two pumps, any attempted alteration of the kinetic situation of the vehicle and translates the said, to continuous rotary movements of the system "side-rotor" of the pump which, moving upon its axis (l ike a nut on a screw), f luctuates its volume and, inversely, the volume of the hydrostatic motor. The axis of the motor (B) does not bear a thread , but only a slot wed¬ ge , within which it may freely sl ide, with a wedge, the system of "side-rotor" si multaneously w ith the rotation of the rotor, whi le in the meanti me there is being continual ly pressed by a hel ikoid spring ( 15) which tends to restore the system to the position of the m ini mum volume o ^f the motor (B)

The hydrostatic motor is the one which moves the wheel and transfers through its vanes, to the vanes of the pump and through those to the rotor, all the inertial torques which the wheels meet whi le moving. And al l these with no interference of electronic sensors and m icrocomputers.

Advantages :

1. With one rel ief valve it replaces the existence of the clutch.

2. It may have a smal l size and handle great pressures

3. Noiseless operation as it has no gears. 4. M ini mum frictions, as it operates in lubricating f luid and m inimal maintenance.

5. Great effectiveness grade.

6. Wide range of transm ission ratios, from 1 :3,5 to 1 :0,50.

7. At its complex form F IG.7, as it needs no differential, the f inal reduction 1 :4 is being placed at the beginning, after the engines f ly wheel, so, the box is being operating at the 1 /4 of the rounds of other boxes, which me¬ ans less noise, heating and vibrations, I it Ie loss of power, therefore better longevity.

FIG.1 is an axonometπc perspective of the system, showing the two pumps (A)&(B) with the two main channels (19) of high pressure and (20) of low pres¬ sure, as well as the connection tubes (16) for chambers (D) and (R) and (17) for chambers (C) and (P). At the said drawing there expressively appear all the details of the two pumps in section, with the driving pump (A) on the left at the position of its maximum volume (overdrive) and the hydrostatic motor (B) on the right, at the position of its minimum volume (overdrive).

FIG.2 is a top cross-sectional view of the BASIC box, for motorcycles, dril¬ ling machines, hoisting cranes, etc. Here there appears the high pressure channel (19) with the entrances of the cross channels (24) and (25), the expan¬ sion valve (13), the drums (3) and the pumps at their positions to (overdrive) again. The final reduction ratio 1:4 (21) is being placed here on the input shaft (8), with the great advantage the transmission box to operate with 1/4 of the engine's rounds.

FIG.3 is a cross-section X-X' to which there expressively appear the three shift leve _DOS ιtιonε (10) ^{s wιtn tne flow} direction valves, the reverse channels (24) and (<_b), the relief valve (23), the spring (7), the mam channels (19) and (20) and the two braking valves (12).

FIG.4 it is the Z-Z ^' section and shows the form of the two diaphragms (5). With the dotted line there is being described the position of the cylinder (1)

FIG.5 the drawing shows a cross-section of the BASIC transmission box pla¬ ced on a four-wheel vehicle with a mechanical diferential, for front-wheel driven or rear-wheel driven vehicles. As it is well-known, every mechanical differential includes the final ratio 1:4 , therefor in this case the hydrostatic transmission have to be placed immediately after the engine ^' s fly wheel and to operate with the engine's rounds.

FIG.βa shows the position of the shift lever (10) at (N) (neutral), the position of the direction valves and the return of the fluid at the channel of low pres- sure without producing any work.

FIG.6b shows the movement of the shift lever to the position (D) (drive), the new positions of the direction valves and the fluid flow from the pump to the motor.

FIG.6c shows the position of the shift lever to (R)(rear) and the inverse of the f luid f low through the cross channels (24) and (25).

FIG.6d shows the position of the braking valve (12) and the f low of the f lu- id through the rel ief valve (23)

FIG.7 is a top cross-sectional view of the transmission at its COMPLEX form with intependent transm ission to both driving wheels. Here both driving pumps are being driven by the same axis, they have the reduction 1 :4 on the input shaft and, as every wheel have its own transm ission, constitute a self-control- leα hydrostatic differential. The wheels are never i m mobi l ized , because the volumes of the hydrostatic pumps and motors are never nul hfyed.

FIG.8 shows a top cross-sectional view of the transm ission at its COM PLEX form, with one driving pump of double volume for both hydrostatic motors. This box, also, has no need of a mechanical differential.

FIG.9 is a front cross-sectional view of the sem i-automatic box.

FIG.10 is a top cross-sectional view of the sem i-automatic box where there is shown its amaz ing si mpl icity in comparison w ith the mechanical and hy¬ draul ic boxes of the previous technical level.

FIG.1 1 shows a mechanical differential of suff isient thicknes which achieves a better tightness by the addition into its body, springs (46) and smal l anti¬ friction metal l ic blocks that compress the two sides of the vanes, as they are passing through . For even better tightnes, four sl iding pieces (44) with the same thickness with the vanes, extent the vanes into the diaphragms body whi le sl iding upon the heads of them due the sl iding bond (48). This drawing also shows a new method of joining the opposite vanes of the ro¬ tor w ith sheet- iron springs (47) in order that they function l ike one piece and one push the other. This is i mportant because on said diaphragm the hel ical springs (46) pressing the vanes make diff icult there movement into the rotors grouves. The sheet-iron springs (two for each vane) accom modate i n different levels into proper cavities (49) in the rotors body.

FIG.12 shows the external view of above diaphragm w ith its cover (45).

The new Inertial Automatic Continuous Variable Transmission Box, at its BASIC edition, i.e. when it drives the wheel of a motorcycle, FIG.1. FIG.2. FIG.3, or the mechanical differential (37) of a four-wheel vehicle FIG.5, consists by:

a) a pair of new-design reversible rotary vane pumps/motors of variable vo- lum, of the type of "moving side" FIG.1 FIG.2 FIG.3 pump (B).

b) a very simple, automatic inertial mechanism FIG.2 (26) (29) (7) which is be¬ ing adapted to the input shaft (8) of the driving pump (A), and:

c) by a relief valve (23), one twin , f low direction valve (10), one twin ^ra¬ king valve (12), one restriction valve (18) and one expansion valve (13).

The pump of "moving side" (B) which will be described hereunder, is the basic element of the hydrostatic box, while pump (A) is similar and only defers at the point that, to this pump has been applied the automatic inertial mechanism.

The pump of "moving side" is a rotary pump with sliding vanes of fixed ec¬ centricity, the one side of which has the ability to move, fluctuating its volume When the moving side of the pump approaches the other side, the volume of the pump is being reduced and when it moves away the volume increases. In order this to be carried out, the one side of the pump has been replaced by a drum(3) FIG.1 FIG.2 FIG.3, which it is not gripped at the axis (14) of the pump, but it may reciprocate eccentπcaly sliding -but not rotating- on one hand on the axis and on the other hand inside the inner surface of the closed cylinder (1) which constitutes an extension of the internal cylinder of the pump. The drum has an absolute contact with the cylinter (1) with Oπngs, so that the majn chamber of the pump to not communicate with the chamber (R) of the cylinder (1) and without, of course, being hindered the reciprocating move- ment of the drum inside it. Inside chamber (R) which is filled with the hy¬ draulic fluid there exists a helical pressure string (15) which adverses the mo¬ vement of the drum backwards, i.e. the increase of the volume o the pump and tents to keep the said at the position of its minimum volume. At the back side of the cylinder there exists a proper opening (3δ) for the hydraulic connection of the chamber (R) with the respective chamber (D) of the pump (A) at the connection of the two pumps at the hydrostatic box. At the internal fase of the drum towards the pump, there is eccentπcaly grip ^¬ ped with a ball bearing, the rotor (9) of the pump with the vanes, in a way

it may rotate with an absolute contact on the face of the drum and so ec- centπcaly that its perimeter will be adjacent to the internal surface of the cy- I inter (1) FIG.3. The drum, the rotor and the vanes, constitute in this way a unique and indivisible flexible system which we will call, furtheron, due to briefness "moving side set" .

The "moving side set" is not gripped at the axis of the pump, but on the one hand it slides with a wedge (<*0) inside the slot wedge (28) of the axis (14) and, at the same time it rotates the axis or, is being rotated by it and, on the other hand, reciprocates inside the cylinder (1) and the cover (2) pas- sing through the diaphragm (5).

The rotor bears at all its length ^ grooves per 90°, within which there slide the same number of metal vanes (6) with the minimum tolerances, (from 2mμ to 40rnμ, depending on the size of the pump). The vanes during their rotation are pressed on the extension of the internal surface of the cylinder (1) inside the mam chamber of the pump, by small springs or by the oil ^' s pressure unter- neath and from the openings (11) PIG.3 which the cy nter bears at the inta¬ ke and exhaustion areas, there comes in and out the hydraulic fluid, towards or from the pump. The other side of the pump is being replaced by a metal diaphragm (5) in a form of disk FIG.4 with a circular opening at the centre, at the same diameter as the rotor and 4 grooves at the width of the vanes. The width of the diaphragm should be adequate and the clearance among the vanes and the width of the grooves such, which woud secure the best possible tightnes, The main chamber of the pump must not communicate with chamber (P) msi- de which there enters the rotor with the vanes. The perimeter of the diaph¬ ragm is being tightened by a crown (4) inside which the diaphragm is being rotating, concentπcaly with the rotor, being drifted by the vanes. When the "moving side set" moves towards the diafragm, one part of the drum enters the chamber of the pump, reducing the volume of it, while the rotor with the vanes are plunged into the diaphragm and tightly pass to the front chamber (P) which is, also, full of the same hydraulic fluid and with a proper opening (39) is being connected through the pipe (17) with the respective cham¬ ber (?) of the pump (A) at the connection of the two pumps at the hydrosta¬ tic box. Finally, the internal diameter of the cover (2) must be concentric and equal to the one of the cylinder (1) so that the vanes, leaving the dia¬ phragm, to be adjacent on the said. The two concentric cylinders (1) and (2) must be perfectly in a straight line between them and well smoothed.

The hydraul ic f luid enters from the inlet (34) of the pump and exits from the outlet (35) and vice versa, because the vane pumps, in general, have the abi l ity of rotating to both directions.

During the construction of the pump there shoyld be given a great attention to its static and dynam ic oi l-tightening of it, by a special ized constructor. One sugestion is the coating of the periphery of the drum with synthetic elastomer Perbunan (Neopren) of adequate thickness, with an additional cover¬ ing of a thin Tef lon layer. The thick layer of elastomer wi l l also handle the expansions between the cyl inder and the drum.

As volume (or specif ic supply) of the pump there is being approxi mately consi¬ dered the difference on the cross-cuts of the drum and the rotor, by the distance (d) each ti me, between the dru m and the diafragm.

As there is shown by the description and the drawings FIG.1 and F IG.2, the "moving side" pump consists of 3 chambers independed among them, of variable capacity : a) The mam chamber of the pump, between the drum (3) and the diaphragm (5), inside which there is being rotating, one part of the rotor with the vanes, at a ti me, and moves the hydraul ic f luid or is being moved by it. b) The chamber (R) which is being surrounded by the cyl mter ( 1 ) inside which the drum reciprocates, and c) The chamber (P) between the diaphragm and the cover, inside which there rec iprocate the part of the rotor with the vanes which are displaced outside the pumping area, during the reduction of the volume of the pump.

Al l these 3 chambers must have the best possible tightness among them, be¬ cause at the hydrostat ic circu it of the box, each chamber of one pump com- municats with a pipe (16)or(17)wιth the respective chamber of the other one and because each pai r of chambers [ (D)+(R) ] and [(C)+(P)] operates w ith dif- ferent pressurs and have a different m ission, thei r f luids should not com muni¬ cate. The same, of course, stands for the mam circuit of the two pumps (A) and (B) which transm its the motion from the engine to the wheel. A l l the chambers and the com munication pipes are f ul l of proper hydraul ic f luid.

At the hydrostatic circuit of the Automatic Inertial Continuous Variable Hydrostatic Transm ission t ere is being used one pair of "moving side" pumps, the mam chambers of which are hydraul icaly connected in series, with channels (19) and (20) and constitute the main closed hydrostatic circuit, where the driving pump (A) FIG.1 , FIG.2, FIG.3 through the hydraul ic f luid transfers its motion to pump (B), which here works as hydrostatic motor, rotating the wheel (T). Except the mam hydraul ic circuit, and secontary chambers are being connected between them in a closed hydraul ic circu it, each one with the respective same one, that is to say (D) and (R) with the pipe (16) and (C) and (P) with the pipe (17). These two hydraul ic systems of com munica¬ ting chambers are the ones which achieve the co-operation of the two "mo¬ ving side sets" of the pump and motor. Final ly the two mam channels (19) and (20) are being bridged over by the cross channels (24) and (25) which do not com municate between them and are used for inverting the course of the motor, without inverting the course of the driving pump FIG.6c .

The continuous changing of speeds is being achived with the continuous displa¬ cement of the "moving side set" of the driving pump (A), accompanied by the continuous inverted displacement of the "moving side set" of the motor (B), because the mam circuit of the system is closed and, in that case, if the volume of pump decreases by -dV- . the volume of the motor w i l l increase by -dV-, and because with the movement of the drum towards the diaphragm , inside the system of com municating chambers (D) and (R), there wi l l be crea¬ ted an underpressure which wi l l force the drum of motor to move to the op- posite direction increasing the volume of the motor. In the meanti me, the rotor with the vanes of the "moving side set", moving towards the diaphragm of the pump, passes through it and one part of it, is being plunged inside the chamber (C), dislodging an equivalent volume of f luid through the pipe ( 17) to the chamber (P) of the motor (B), pressing the f rontage of its rotor assisting thus the "moving side set B" to withdraw increasing the volume of the motor. At any position of the "moving side set A" of the pump (A) there corresponds and one inverted position of the "moving side set B" of mo¬ tor (B). Yet this corresponds to the changing of the coupl ing of gears at the mechanical gear boxes and because each position of the system is a different transm ission ratio and these ratios are inf inite, therefore the sa id box may offer inf inite speeds.

For the movements of the "moving side set" there operates a si mple, automa¬ tic, inertial mechanism. The said mechanism is being driven directly by the morphology of the ground (gradient of the road, turns, load, etc), by the resi¬ stance of the wind and, in general, by any reason which reacts to the motion of the vehicle or to the alternation of its kinetic situation, acting directly to the rotor of the "moving side set A" of the driving pump, through its va¬ nes and the vanes of the hydrostatic motor and exploiting, each ti me, the differance of rounds which results between the axis and the rotor of the pump when the transm ission ratio is not the proper one, moves the "moving side set A" unti l the pressure between the vanes (a) and (b) FIG.6b be balanced with the extent of the co-operating springs (7) and (15) FIG.1 , FIG.2 at that time, when it ceases, keeping this position unti l a new inertial reason forces it to move again.

The automatic inertial mechanism consists of : a) a clockwise screw, of a wide pitch (29) b) a nut (26) of the same wide pitch as the screw, being gripped at the cen¬ tre hole of the rotors cylinder, c) two hel icoid pressure strings (7) and ( 15) FIG.1 and FIG.2 and d) a disk-shaped pressure ball bearing (36)

The axis of the driving pump (A) is being forme d to a clockwise wide pitch screw. At the centre hole of the rotors cyl inder of the "moving side set A" there is being gripped a wide pitch nut (26) of si m i lar thread with axis screw so that the rotor, drifting al l the "moving side set A", to be able to move along the whole length of the screw, whi le rotating on it (l ike a screw with a nut). The nut also connects-with a bal l bearing (33)-the rotor w ith the drum.

The margins of the transm ission ratios which may be offered by the box are al most inf inite and depent on the use for which it is intended, in any case for its placement to passenger vehicles a range of ratios f rom 1 :3,50 ( 1 st) to 1 :0,50 (overdrive) is remarkably suff icient.

When the box passes f rom the movement to park ing, the "moving side set/* " of pump (A), due to the extention of the co-operating springs (7) and ( 15), rotating on its axis clockwise, is being pushed away f rom the diaphragm and reaches the predestined marginal position (40) of the max i mum volume of

th is pump, while in the meantime the "moving side set B" of the hydrostatic motor (B) is being pushed inversely, sliding in its slot wedge and occupies the predetermined position (41 ) which is closest to the diaphragm and is the position of the m inimum volume of motor (B). FIG.1 , FIG.2. Therefore when the input shaft stops to rotate the transm ission returns to overdrive position.

The surfaces of the two vanes (a) and (b) (one of each pump) FIG.3, FIG.6b which are located at the positions which def ine the area of compression of the hydraulic f luid and are the ones which compress the hydraul ic f luid, under- taking all the load of the transm ission of the motion to the wheel, are in pro¬ portion with the volume of each pump and their surfaces are being altered in proportion with the alteration of the volume of the said pumps.

At the operation of the hydrostatic box, between the vanes (a) and (b) there is being developed a pressure which is in direct ratio with the torque of iner¬ tia which opposes the motion of its motor. According to Pascal' s Law, this pressure has the same value at every point of the space being included be¬ tween the vanes (a) and (b). The moving parts of the box situated inside the compressed space, are the two drums (3) FIG.3 and the two vanes (a) and (b), yet because the chambers (D) and (R) behind the two drums communicate be¬ tween them through the pipe (16) FIG.1 FIG.2, and the diameters of the drums are equal, the pressures are counterbalanced and the drums may not withdraw both of them at the same time. Therefore the only elements which may be moved by the pressure are its vanes.

The shift lever of the automatic box, has the fol lowing selections : (P) ^D arkιng - (R) Rear - (N) Neutral - (D) Drive - (L) Low - (Lo) Lock

At the positions (R) (N) and (D) the valve (18) of the pipe (16) is being conti- nually open, while at the position (L) is half-closed and at the position (Lo) the valve is closed. At the position (P) the vehicle is being mechanicaly i m¬ mobi lised, the engine may operate yet the box does not participate.

^■ v.

Operation of the BASIC box, on the vehicle.

When the vehicle is parked, the box is at the ratio 1:0,50 (overdrive) on acca- ount of the tension of the springs, and the pump has its maximum volume while the hydrostatic motor its minimum volume. To start the engine , we move the shift lever to (N) Neutral, where the valves of direction of flow (10) receive the intermediate positions, as shown in FIG.6a After starting the engine, the pump starts rotating with no load because the hyraulic fluid, through the cross channel (24) returns to the inlet (34) of the pump without moving the hydrostatic motor. When, following that, the selec- tion lever is being placed to the position (D) Drive, the valves (10) close the cross channels (24) and (25) FIG.6b and the fluid, pressed by the vane (a) of the pump presses the vane (b) of the motor. The transmission ratio at resting is 1:0,50, and because the surface cf the driving vane (a) is twice as much as the surface of the moving vane (b), the effort on the vane (b) at idling is ve- ry low and so the hydr. motor may not overcame the torque of inertia. Resu¬ lt , the pressure between the vanes highly increases and the rotor of the pu¬ mp, surpassing the power of the springs (7) and (15), starts screwing on the turning axis, together with the " moving side A" towards the diaphragm, con¬ tinuously decreasing the pumps volume, while in the meantime the "moving side set B" of the motor, moves inversely , increasing its volume. This has as a result the box to shift down, automaticaly, approaching the 1st speed. At a certain point of the course of the system, the continually increasing ten¬ sion of the springs and the continuous decrease of the surface of the vane (a) will balance with the continually increasing surface of vane (b) and the conti- nually increasing of the pressure between the vanes will stop the rotor, because the ratio which has been formed is the proper one, so that the vehicle would start. If during the time that all this happen, the vehicle is immobilised with the foot brake, the "moving side set A" will continue its course, because the resistance of the vane (b) is being unrivalled, the pressure will increase more and slightly after the 1st speed there will open the pre-adjusted relief valve (23) and the hudraulic fluid will pass directly to the inlet (34) of the pump After that, the ratio of the box it will remain slightly below the 1st speed and the valve (23), opening and closing continually like an automatic hydrau¬ lic clutch will permit to the pump to rotate without the engine to stall. FIG.6b In case that the vehicle can not start, because it is parking at an uphill road the driver, by pushing the accelerator he offer more power and rounds to the axis of the pump and its new increased torque will cover the inertial resist¬ ance due to the gradient of the ground and the vehicle will start.

At the acceleration on an horizontal road, al most al l the torque of the engine is being consumed for the increase of speed, as the inertial torques are being l i m ited to the inertia of moving masses, the resistance of the air, and the rol¬ l ing resistance of the wheels. Therefore the pressures between the vanes are drastical ly redused, the expansion tension of the springs supersedes and the rotor continual ly withdraws to overdrive, having al l the ti me the ideal ratio of transm ission.

When the vehicle, after an horizontal course, enters an uphi l l road the box wi l l quickly read the inertial torque which wi l l be developed to its vanes and wi l l instantly adjust the "moving side set A" of it in order to handle the new situation.

In case that the load tends to drift the vehicle, such as in a downhi l l road, the motor becomes a pump and the pump becomes motor and the vehicle starts being drifted and accelerating. If the driver, whi le reaching the down- hi l l, slow down with the brake, as the box f inds resistance it wi l l automatical¬ ly down shifts, and the driver moving the lever to the position (Lo), locks the existing speed in the box and the vehicle decl ines slow ing down by the engine. This hapen because at the position (Lo) there closes the restriction valve (18) on the pipe (16) FIG.2 which connects the chambers (D) and (R) and then the drums of the pump and of the motor can not move, anymore, and the box maintains the ratio it had, before the driver has placed the lever at the position (Lo).

Rear : When driver shifts to (R) the direction valves receive the positions shown in FIG.6c and the f luid f low, passing through the cross channels (24) and (25) which do not com municate between them, reverse the moving directi¬ on of the hydrostatic motor, with a very si mple and noiseless way. The said reverse is being possible even if the vehicle is sti l l moving and it may be used as a panic brake. As it is shown at the drawings, the operation of the rel ief valve (23), is not affected by the inverse of the movement be¬ cause the pump (A) is not be inverted. At the reverse motion, the box keeps changing ratios which serves to a long reverse course.

Braking : w ith the box, at the axis of the hydrostatic motor : F IG.Sd Pressing progressively the brake, the restriction valves ( 12) start closing, de¬ celerating even more the hydrostatic motor and when the valves are comple¬ tely closed the motor and the wheels stops moving. At this procedure the hydraul ic f luid with its kinetic energy and its pressure

assists the valves to close, as shown at the drawing, that means a " Power Braking " This applying of brakes would not be possible if the eccentricity of the rotor on the drum had been such that it would leave some interval between the cyl inder ( 1 ) and the rotor.

For park ing, of course, the shift lever have to be placed to the possition (P), where it must exists a mechanical hand brake.

During stopping with the foot brake or the hand brake, the engine does not stal l, because the high pressure activates the pre-adjusted rel ief valve (23).

The BASIC box may be placed at large motorcycles , at four wheel vehicles with front or rear drive, in combination with a mechanical differential, to dri l l ing machines , to trains, airplanes, copters and wherever a variable torque is required.

Operation of the COMPLEX box:

The said box is designed to be placed to every , 4wheel or 4wheel-dπve vehicle and is the automatic hydrostatic box, to its most perfect form.

Every driving wheel has its own independent box, whi le the engine moves with a single axis, both driving pumps. Therefore each driving wheel has its own, independent, transm ission. FIG.7.

When the vehicle enters a curve, the box of the internal wheel, as this wheel meets resistance, wi l l reduce speed in proportion whith the radius of the curve and the wheel wi l l lose rounds, increasing its toque, whi le the box of the ex¬ ternal wheel, since it wi ll face a reduced resistance, wi l l increase the speed in proportion to the radius of its curve, which is much larger than the radius of curve of the internal wheel and, therefore, the external wheel wi l l increase its rounds reducing its torque. In case that one of the wheels meets a ground of reduced adherence ( water, oi l, pebble etc.) the other one w i l l continue moving with the speed which it had, w ithout the di rect ion of the vehicle to be affected.

K ickdown: In case of a rush to lower the ratio, instantly, for a qu ick surpas¬ sing the driver may force a downshift by pushing the thrott le to the w ide- open posit ion and the box due to the inertia of the kinet ic energy of vehic le w i l l instantly lower the speed ratio to faci l itate its accelerat ion. The COM PLEX box, at the front wheel drive veh icles is being placed in f ront or under the engine, whi le at the rear wheel driven vehicles, at the position

of the differential, or it is being separated to three parts where the two dri¬ ving pumps is being connected to the engine ^' s fly wheel and the two indepen¬ dent motors each one of them near each wheel and, of course, they are con¬ nected with the two pumps with extensions of the channels (19) and (20) and of the pipes (16) and (17).

At the COMPLEX box of FIG.8 the two driving pumps are being replaced by one driving pump of double volume (2A), the axis of which is being connec¬ ted to the engine's fly wheel throuch the so called final ratio (here first ra- tic) The main channels (19) and (20) are being branched off and supply the two motors (B), while the secontary channels are being branched too, connec¬ ting the same chambers, The volumes of the two motors are independent to each other, yet always their sum, equals with the volume of the driving pump (2A). The hydrostatic differential of this box works as a common mechanical one, but, it has the advantage that the wheels are never immobilized because the volums of the two motors are never nullified.

Semi-automatic hydrostatic box :

If from the basic, automatic inertial, hydrostatic box, we remove the automa- tic inertial mechanism and we add a manual lever, which will move the drum (3) of the pump (A) FIG.9 and FIG.10 then we have e very simple Semi-auto¬ matic hydrostatic box, of scaled or infinite linear ratios, with its own clutch, its own brake and with its own rear box circuit.

RemarKS:

1/ For cooling the box there are being required cooling vanes. 2/ For the expansion of the hydraulic fluid, there exists an expansion valve (13) 3/ For the possible refilling of external oil losses there will be required a small pump which will be driven by the axis of the pump (A) and an oil reservoir.

4/ At the drum of pump (A) there exists a terminal escape valve (27) which opens when the drum comes near the end of its course, because in case that fluid leaks from the pump chamber to (D) chamber, the drum will not end its course at resting position (40).