CA1070527A - Apparatus for variation of speed - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A transmission device serving to transfer a mechanical power between a coupling means and a coupling member which is driven with a rotary movement, which transmission device comprises:
a frame; a first member having two rolling surfaces of resolution about a first fixed axis relative to the frame and located on either side of a plane perpendicular to the first axis at a point S of said axis; a second member having two rolling surfaces of resolution about a second axis coinciding at point S with the first axis and forming an angle a located on either side of a plane perpen-dicular to the second axis at a point S of said axis; supporting means which move at the speed ? relative to the frame and supporting the said second member in such a way that the angle a of the second axis relative to the first axis is fixed and in such a way that the movement of the second member about point S is the combination of a rotary movement of speed ? about the second axis and a conical movement of apex S
of speed ? of the second axis about the first axis; first con-necting means between the coupling means and one of the two following members; the second member or the supporting means in such a way that the conical movement of speed ? is induced or obtained; second connecting means between the coupling member and the following two members: the second member or the first member; a system which applies the rolling surfaces of the second member against the rolling surfaces of the first member at two points P1 and P2 positioned on either side of the first and second axes; and means for modifying the position of the contact points between the rolling surfaces in such a way as to vary the transmission speed ratio.

Description

~o705~7 APPA~ATUS ~OR VARIATION OF SPEED
The present invention relates to a mechanical ~ransmission device.
It more specifically relates to a friction trans-mi~sion device for transferring a mechanical power between coupling means and a coupling member having a rotary move-ment without creating an axial torque on the coupling member or on the coupling means.
PRIOR ART
l¢ Friction transmission devices are ~nown which have an input shaft an~ an output shaft coupled to rotary members, cooperating via rolling surfaces and comprising means for modifying the r~lative position of the rolling surfaces in such a way as to vary the transmission ratio.
Transmission devices or variable drives of this type ha~Je ~een more particularly described in Canadian Patent No.
99~,857, issued October 26, 1976 to Vadetec S.A.
Such transmis~ion devices comprise:
a3 a frame;
b) a first member comprising two rolling surfaces revolving about a first axis fixed relative to the frame, located (preferably symmetrically) on either side of a plane perpendicular to the first axis at a point S of said axis;
c) a second member comprising at least two rolling surfaces revolving about a second axis coinciding at point S with the first axis and forming with the latter an angle a, located (preferably symmetrically) on either side of a p7 ane perpendicular to the second axis at the point S of said axis;

.~ . .

` ~7~527 d) supporting means mounted so as to move at a speed relative to the frame, supporting the second member in such a way that the latter can rotate on itself about the second axis at speed ~ in such a way that the movement of the second member about the point S is the combination of a rotation movement at speed ~ about the second axis and a conical movement of apex S at speed ~ of the second axis a~out the first axis;.
e) first connecting means between, on the one 10 hand, the coupling means comprising a main drive shaft and on the other hand the second member or the supporting means (in the circumstances, these connecting means are more particularly constit~ted ~y an extension having a prismatic cross-section integral with a main drive shaft) in such a way that the coupling means actuate the conical movement of the second member (or conversely are actuated by the second member);
f) second connecting means between a coupling member comprising a main drive shaft and one of the following 20snembers: the second member or the first member (in the circumstances these connecting means more particularly comprise a homokinetic joint located between the second member and a rnain drive shaft);
g) a mechanical system applying the rolling surface of the secon~ mem~er against the rolling surface of the first member at two points P~, P2 located on either side of ~he first axis and the second axis (in the case of the known transmission device described in ~forementione~ Canadian Patent ~o. 998,857, this mechanical system comprises gyroscopic means);

107~527 h) means for modifying the position of the contact points between the rolling surfaces in such a way as to vary the transmission ratio between the movement frequency of the coupling means and the movement frequency of the coupling member.
A transmission device of this type is particularly well suited for the transmission of high power by creating in a particularly simple manner (by means of the gyroscopic means) the normal contact pressure between the first member 10 ana the second member, whilst avoiding (due to the subdividing into two of the rolling surface~ on either side of the point S) the application of axial forces on the one hand to the -coupling member and to the coupling means constituted by the main drive shafts and the other, the bearings supporting the second member or the first member.
Moreover, due to the means for modifying the p~sition of the contact points ~comprising varying the slope of angle a of the second axis relative to the firs~ axis) it is possi~le to vary the ratio of the input speeds and the output speeds.
However, no matter how elaborate this transmission device, it has certain disadvantages, which can be relatively troublesome in certain constructional variants.
These disadvantages are due to the fac~ that, in the prior art, transmission devices it is necessary to provide a degree of freedom in the radial direction parallel to the meridian plane of the first and second axes, in such ~ way that the second member can, under the action of the tor~ue created by the gyroscopic means, tilt and engage against the first mem~er.

~ he necessity of providing a tolerance in a radial direction leads to the following disadvantages: firstly, the second member can oscillate radially when it rolls on the first member, whereby said radial oscillations of the second member can damage the rolling surfaces and cause lack of stability of the oil film in the contact area of the rolling surfaces, whilst said oscillations also cause fluctuations to the contact pressure which are prejudicial to the satisfactory operation of the transmission device~
Secondly, there is no doubt that it is often difficu~t, if not impossible, to obtain mechanical connec-tions (more particularly by gears) between two members which have an uncertain gap between them. This problem of mechani-cal connections is in the case of the transmission devices according to the present invention a serious problem which have at least two effects: on the one hand, it is necessary to provide in certain constructional forms, mechanical con-nections between the second member (or a member associated with the second member such as supporting means) and 20 auxiliary mechanisms which it is necessary to drive at speeds which are synchronous with the speed ~ of the second axis about the first axis.
On the other hand, it is necessary to provide in the case o~ transmission devices according to the invention, first and second connecting means between the coupling means, the coupling members and the first mem~er, second member and su~porting means, whereby it is also necessary to provide in the case of certain constructional variants, other connect-ing means between the frame and the second member in order - 1~70527 more particularly to stop the rotation of the second member (in such a way that ~ = 0, /a~ = /~ /).
It is pointed out in this connection that ~ is the rotation speed of the second member on itself, about the second axis, measured in an absolute reference mark linked to the frame, ~ is the rotation speed of the second member measured in a rotary reference mark linked to the first axis and to the second axis, whilst the algebraic relationship O* O O
~ a 10 exists between ~ and ~ . Consequently, in the case where ~ z O, the second member is fixed against rotation about ~he second axis and relative to the frame, but it translates in nutation at the speed a relative to the first axis.
The necessity of maintaining a radial degree of freedom thus complicates the construction of the mechanical connections.
Thirdly, it is necessary to stress that mechanically the gaps (and the resulting oscillations) are often a source of los~es by mechanical friction or a source of wear. A
20 fundamental quality of a good transmission device is good efficiency.
THE OBJECT OF THE PRESENT INVENTION

-The object of the present invention is to provide a transrnission device having the same advantages as the known transmission devices, but which does not have the disadvantages descri~ed herein~e~ore.
In other words, the present invention relates to transmission devices of the type described hereinbefore which are able to transmit hiqh power, whilst keeping the roll~ng .' ~0705'~7 surfaces engaged with one another, without sliding and without axial forces of reaction being created and which permit a simple and rapid variation of the transmission ratio.
With reference to these transmission devices, the problem solved by the invention, is to as far as possible eliminate the disadvantageous consequences due to the more or less uncertain clearances between the rolling surfaces.

THE TRANSMISSION ~EVICE ACCORDING
TO THE PRESENT INVENTION

According to the present invention, there is provided in a trans-mission device having a frame, drive input means, and drive output means, means interconnecting said input and output means comprising: a first element on a first axis fixed in the frame and having rolling surfaces of revolution about said first axis, one such rolling surface on each side of a first plane perpendicular to said first axis at a point of axes intersection; a second element on a second axis intersecting said firs~ axis at said point of axes intersection ant having concentric journal and rolling surfaces of revolution about said second axis, the rolling surfaces of said second element being disposed one on each side of a second plane passing through said point of axes intersection and perpendicular to said second axes intersection and perpenticular to said second axis; support means rotatable on said first axis and journalled with said journal surfaces to support said second element for movement in a biconical path circumferentially of said first axis, the apex of said biconical path being coincident with said point of axes intersection;
the respective rolling surfaces on said first and second elements being in r~lling frictional engagement at two points of contact in a third plane con-taining said first and second axes and located one on each side of said first plane; the rolling surfaces of at least one of said elements being defined by generatrices inclined oppositely with respect to the axis of revolution there-of and symmetrically with respect to said point of axes intersection, thereby 1~70527 to provide in the respective rolling surfaces of said first and secondelements a variable ratio of rolling surface radii at said points of contact for variation in the spacing of said points of contact from said point of axes intersection; and means for forcing said respective rolling surfaces on said first and second elements into rolling friction engagement with each other at said two points.
These supporting means can be constructed in different ways~
Hbreinafter,special embodiments will be described with reference to the drawings. They can, for ex~mple, comprise at least two series of bearings, the first permitting a rotation of the second member relative to the frame and the second permitting a rotation of the second member relative to the supporting means about the second axis, said two series of bearings being inclined relative to one another.
Due to this arrangement of the supporting means and the fact that the second element moves in a biconical path, it is obvious that one of the main causes of the uncertain radial clearance between the rolling surfaces is eliminated. Moreover, this simplifies the connections between the coupling member or the coupling means and the second member or the supporting member, because henceforth, the latter are oriented in fixed directions relative to the frame.
Because the second element moves in a biconical path circumferential-ly of the first axis, the slope angle a of the second axis relative to the first axis is fixed. This means that, contrary to what happens in the prior art transmission device, the second member cannot swing around the point of axes intersection S relative to the first member. It also ~eans that the orientations in the space of the second axis relative to the first axis have no degree of freedom. It should also be noted, however, that this does not exclude the case where the slope angle a is adjustable. That is to say that when the second axis can assume several different inclinations relative to the first axis and where for each of these inclinations (caused directly or indirectly by an appropriate mechanism, more particularly in order to modify the transmission ratio, for example) the second member has no degree of oscillating freedom relative to the first member.
As the ideas which have just been developed are relatively complex, it is perhaps necessary to study them from a different angle based on a mechanical analysis of the forces applied at the contact points of the rolling surfaces.
In the first case, i.e. the case of a prior art transmission device ~in the case where the slope angle a has a degree of freedom) a mechanical torque is applied to the first or second member and generates at the contact points of the rolling surfaces a force and therefore a pressure which, in normal operation, prevents the sliding of the rolling surfaces relative to one another.
In the second caseJ i.e. with the transmission device according to the present invention~in the case where the slope angle of the second axis relative to the first axis, is fixed, no matter whether it is adjust-able or not) a torque applied to the second member produces no normal force or pressure at the contact points because movement about point S
6f the second member relative to the first member is prevented. Therefore, in this case, different mechanical systems are used for applying the rolling surfaces of the second member against the rolling surfaces of the rotary member.
COMPLEMENTARY PROBLEMS AND THEIR SOLUTIONS
In complementary manner, the preferred embodiments of the components forming the transmission device are more specifically designed in such a way that the transmission device has at least the same advantages as the prior art transmission devices.
Thus, in embodiments of the transmission device, the following complementary pro~lems have also ~een solved:
the problem of varying the transmission ratio without modifying ... ..

the slope angle a (point 1), whereby in order to simplify the mechanical connections between the moving members and the coupling members or the coupling means, it is desirable to avoid any variation in the slope angle ~i the problem of creating the contact pressure at the contact point between the ~olling surfaces ~point 2), whereby said problem is preferably solved in combination with the problem of varying the trans-mission ratio;
the problem of the mechanical connections (point 3);
the problem of balancing the forces of reaction on the bearing supporting the second member (point 4);
the problem of balancing the forces of reaction on the frame (point 5).
In order to simul~aneously solve these different problems and the fundamental problem of the present invention, novel members have been designed or the prior a~t members have been adapted, modified, operated and combined with the supporting members in such a way that it is simultaneously possible to achieve often contradictory objectives.
Thus: point 1) To solve the complementary problem of a variation of the transmission ratio without modifying the slope angle a, the rolling sur-faces of one of the two members are generally conical and have a half-angle at the apex which is substantially equal to the slope angle of the second axis relative to the first axis, whilst the rolling surfaces of the other member have a substantially annular configuration.
~he term "generally conical" signifies that the generating curves of the rolling surfaces, viewed in a meridian p~ane passing through the axis of revolution of the rolling surfaces do not greatly vary from a straight line. This also means that the angles of the tangents of these generating curves, relative to the axis of revolution do not vary very much from an average value called the "half-angle or apex angle of the cone."
Thus, the terms "half-angle or apex angle of the cone" must not be understood in the strict sense of the word and must not be limited to the simple designation of "cones" or "truncated cones, " whose generating lines are straight lines. These terms have been used for ease of reference, making it necessary to redefine their geometry whenever the shape of the rolling surfaces is mentioned.
In the same way the term "annular," used for qualifying the shape of the other rolling surface, must not be understood as limited to strictly cylindrical structures. In other words, the annular rolling surfaces, namely the functional parts of the annular rolling surfaces which come into contact with the conical rolling surfaces, are substantially cylindrical (the average tangent at their generating line being substantially parallel to their axis of revolution).
It is obvious that the combination of generally conical rolling surfaces and annular rolling surfaces can lead to the same result as strictly conical and cylindrical rolling surfaces (i.e. the modification of the transmission ratio without modifying slope angle ~, whilst providing the complementary advantages which will be . ...

107~527 described with reference to specia7 embodiments. The terms ~conical, n "conically shaped," "with a generally conical configuration, n "annular" and "cylindrically shaped" must not be understood in their strict sense and wherever they are used, they must be interpreted so as to take account of what has been said hereinbefore.
As a result of this arrangement and construction of the rolling surfaces, there is no need to modify the slope angle of the second axis relative to the first axis for varying 10 the transmission ratio. It is in fact sufficient to axially move the substantially rolling surfaces and/or the conical rolling surfaces relative to one another to modify the position of the contact points Pl and P2 and therefore the transmission ratio.
Reference is briefly made to the principle of this transmission ratio variation mechanism: the kinematic equation also called transmission equation is:
o o o o Rl ~ - + (a ~' ~) R =
or:
o O O* R
~ - -'~ Rl =
in which:
designates the speed of the second axis about the first axis, ~ designates the rotation speed of the second member a~out the second axis, measured in an absolute reference mar~
lin~ed with the frame;
~,*
B designates the rotation speed of the second member a~out the second axis in a rotary reference mar~ linked to the first axis and to the second axis;

~ designates the rotation speed of the first m~mber about the first axis when the latter is, in the case of certain variants, mounted so that it rotates relative to the frame;
Rl designates the radius of the circle described by one of the contact points on the considered rolling surface of the second member;
R2 designates the radius of the circle described by one of the contact points on the considered rolling surface of the fi~st member.
This equation was def~ned by the Applicant in the aforementioned Canadian Patent No. 998,857.
It is clear that a modification of the position of contact points Pl and P2 causes a variation in the ratio of Rl/R2 and therefore a variation in the ratio between any O O O
two of the speeds a, ~ and ~. It will be shown hereinafter how it is possible to remove the indefiniteness appearing in the case where the first member is mounted in rotation at the speed ~.
In this connection, it is pointed out that this 20 special conical shape of the rolling surfac~s is known per se. Rolling surfaces having such a conical shape are speci-fically described in U.S. Patents No. 2,319,319 ~GRAHAM), ~o. 2,535,409 (GRAHAM) and No. 2,405,957 ~JONES). However, it is essential to point out that the transmission devices described in these U.S. patents only have a single series of rolling surfaces. In other words, they do not have the essential characteristics of the transmission devices covered by the present invention; namely, that the rolling surfaces are subdivided into two and located on either side of a point 5, whilst the slope angle a is strictly fixed.

Admittedly, in the case of the GRAHAM transmission device of U.S. Patent No. 2,535,409, a conical planet wheel is forced and locked against an annular ring by means of wedges but on the one hand such means would appear to he incompatible with a subdivision into two of the rolling surfaces (it is virtually impossible to forced-support a member at four points) and on the other would be unable to prevent, even if arranged symmetrically relative to a point S, the development of an axial reaction component ~it is 10 virtually impossible to strictly balance the forces of reaction brought about by a member supporting by force at four poin~s).
Moreover and correlatively, the means (wedges) provided in the GRAHAM transmission device of U.S. Patent No. 2,535,409 do not maintain constant the slope angle a.
In fact, they imply a certain elasticity of the planet wheel and therefore a certain variation of the angle a, without which it would not be possible to maintain the planet wheel supported against the annular ring.
These essentially structural differences lead to a large number of disadvantages which are not found in the transmission device according to the present invention and these are more particularly: the bearings which support the rotating members must be designed so as to resist the axial forces; the mechanical connections between the rotating members and the frame must ~e designe~ so as to permit the variations of the slope angle a and are a source of oscilla-tions or losses which decrease the efficiency of the trans-mission device.

~,~
,. ~

107~5Z7 In our Canadian Patent No. 1,031,984, granted May 30, 1978, the applicant also described conical and annular rolling surfaces. This patent which was still not published on the priority date of the present application, is referred to here for information purposes.
In the case of this latter patent, the rolling surfaces are subdivided into two, so that the problem of balancing the axial reaction forces is solved. However, the slope angle a has a certain degree of freedo~, i.e. the second member is mounted with a slight clearance so that it can swing and engage against the first member.
Thus, this transmission device, although it is an improvement because it makes it possible to vary in simple manner the transmission ratio, still has the disadvantages associated with possible random variations in the slope angle a.
According to a further complementary characteristic hhich may contribute to solving the problem of varying the transmission ratio, the annular rolling surfaces may be mounted so as to be axially movable and the means for modifying the position of the contact points between the rolling surfaces comprise members for actuating the annular rolling surfaces.
As a result of this special construction, it is possible to vary the transmission ratio by axially displacing the annular rolling surfaces along the generating line of the cone parallel to the axis of revolution of the annular rings.

" "
.j . -~

,. ... ,: :, A~cording to another feature relative to another embodiment, the annular rolling surfaces are mounted in axially movable manner and the means for modifying the position of the contact poin~s between the rolling surfaces comprise members for axially actuating the conical rolling surfaces mounted in axially movable manner.
As a result of this special construction, the gap between the second member and the first member is modified symmetrically or asymmetrically in such a way that in the 10 first case the annular rolling surfaces actuated by the system creating the contact pressure can move until they abut against the conical rollin~ surfaces or in such a way that in the r second case, the contact pressures at Pl and P2, on either side of the point S are unbalanced and give rise to an axial component which is able to displace the annular rolling surfaces. It is clear that the general solutions and special preferred embodiments described hereinbefore are perfectly compatible with the means making it possible to keep fixed the slope angle a, because they specifically aim at main-20 taining slope ang~e a constant.
It is also certain that the solutions described hereinbefore and which solve the problem of varying the transmission ratio also contribute to solving the fundamental problem of the present invention. Thus, it is easier to prevent radial clearances between the second and ~irst m~mbers, maintaining the slope angle a fixed because there is no need to vary the angle _ in order to modify the trans-mission ratio. In other words, it is easier to prevent annular clearances between two members when their angular orientation is defined once and for all. Thus, the solution adopted for solving the problem of the variation of the transmission ratio is not independent of the solutions of the fundamental problem of the present invention, in fact they cooperate with one another.
However, it should be noted that this solution of the problem of varying the transmission ratio applies no matter whether the angle a is fixed or not. Reference has already been made to an earlier-dated patent of the present applicant, namely No. 1,031,984, which specifically describes ~ariants of effecting this solution in the case where the slope angle a has a certain degree of freedom.
Moreover, as will be seen more particularly in point 3 ~, hereinafter and during the detailed description of special embodiments, this solution of the problem of the variation of the transmission ratio by conical rolling surfaces can be utilized with a wide variety of systems creating the contact pressure.
Therefore, the solution involving the conical rolling surface tescribed hereinbefore has a broad scope and can be claimed in a more general manner, i.e. other than in combination with special systems for creating the contact pressure (gyroscopic system) described in the above-mentioned Patent No. 1,031,984.
To solve the problem of creating the contact pressure: the rolling surfaces of one of the members may be mounted in axially movable manner and the system which applies the rolling surfaces against one another may comprise means for axially actuating the rolling surfaces mounted in axially movable manner.
This system construction which creates the contact pressure at contact points Pl and P2 is not independent of the fundamental characteristic of the present invention which consists of maintaining the angle a fixed.
Thus, with the angle a maintained fixed, it is no longer ~' ...

possible to envisage the bringing into contact of the rolling surfaces and the creation of the contact pressure according to the prior art by the second member freely swinging about point S.
Thus, the mechanical system must be designed in such a way that the second member is applied against the first member without a free angular variation of angle a being necessary.

1~70527 This is the case in the system describea hereinbefore which comprises axially displacing the rolling surfaces of one of the members without changing angle _.
French Patent No. 1,227,486 (HEUR~EL) describes a transmission device comprising a conical roller which can displace axially by a small amplitude under the action of a spring.
It should be noted however: on the one hand that this transmission device is not of the type covered by the 10 present invention because it does not have two pairs of rolling surfaces arranged symmetrically in such a way that the axial forces of reaction are eliminated and on the other said swing which axially actuates the rolling surfaces does not create a contact pressure and in fact belongs either to a disengaging mechanism or to a wear-compensation mechanism.
In other words, the spring according to the teaching of the above French patent does not have the function of developing a contact pressure between the roller and the ring so as to ensure their driving without sliding. It must, 20 in fact, be remembered that in the case of the HEURTEL trans-mission device, driving is produced by "simple adhesion" of the smooth surfaces (line 4, left-hand column of page 3).
It should be noted here that the fact that the contact pressure is created by a system which is independent of the ~inematic operating conditions provides the advantage of permanently maintaining an ade~uate contact pressure, ~, c~ ~
even in transient states when the speed-. ~, 2 and ~ can vary. In the case where this system comprises gyroscopic 1~705Z7 means according to the teaching of aforementioned Canadian Patent No. 998,857 it is sensitive to accidental variations of the kinematic conditions. In this connection, the use of an independent system constitutes an advantage compared with that used in the prior art.
It should also be noted that the fact that angle a is fixed facilitates the provision of the independent system for creating the contact pressure. Therefore, as the second member always has a fixed orientation, it is possible to 10 utilize it for pressing the rolling surfaces thereof. In other words, the fact that the slope angle a is fixed cooperates with the other structural dispositions Gf the transmission device in order to facilitate the realizations of the systems creating the contact pressure.
The system for creating the contact pressure can be realized in various ways.
In the case of certain embodiments, the means for axially actuating the said rolling surfaces mounted in axially movable manner can have an inertial origin. In this case, ~0 the rolling surfaces mounted in axially movable manner are preferably those of the second member and are ~ormed on two annular rings, whose axis is the second axis, inserted between the first member and the second member and integral in rotation O*
at the speed ~ , of the second member.
For example, the means having an inertial origin can comprise annu~ar rings having a mass and geometry, as well as rolling surfaces of the first mem~er having a pro~ile such that two axia7 forces are ~eve70ped and have the effect _ ~9 _ ~F f of axially displacing the annular rings towards the rolling surfaces of the first member and of creating the contact pressure.
In the case of other embodiments, the means for actuating the rolling surfaces mounted in axially movable manner can comprise an elastic system. In this case preferably:
the rolling surfaces of the second member are mounted in axially movable manner;
the rolling surfaces of the first member are two truncated cones juxtaposed by their base, whose apex half-angle is slightly less than the slope angle a of the second axis relative to the first axis;
the means for axially actuating the two rolling surfaces of the second member against those of the first member by creating the contact pressure comprise two elastic systems, each supported on the one hand on the second member and on the other on the rolling surfaces of the second axially movable member.
~0 In the case of other embodiments, the means for ac~uating the rolling surfaces mounted in axially movable manner with a view to creating the contact pressure comprise ra~ps and in this case preferably:
the two rolling surfaces of the second member surround the first member;
the two rolling surfaces of the first member, mounted in axially movable manner on the first member are two trllncated cones juxtaposed by their base, whose apex half-angle is equa~ to the slope ang~e a of the second axis relative to the first axis;

the means for axially actutating the rolling surfaces of the first member against the rolling surfaces of the second member comprise a system of ramps integral with the first member and cooperating with complementary ramps integral with the rolling surfaces of the first member.
More specifically, in this case, the ramps are of the helical type, in such a way that the rolling surfaces of ; the first member are automatically screwed onto the first member during the operation of the transmission device.
These special constructions of the system which creates the contact pressure by means of ramps integral with the members (integral with the first or second members) have the substantial advantage of preventing relative slipping of the rolling surfaces under the action of the output torque (or a driving or reactive torgue) of an excessive nature. Thus, the contact pressure created ~y such a system of ramps is directly proportional to the output torque, so that the contact pressure is continually adapted to the value of this torque, whatever it is.
It must~be stressed that the problem of varying the transmission ratio cannot be solved independently at that of creating the contact pressure, because in one case it is a question of finding solutions permitting the modifi-cation or the position of contact points Pl and P2 and in the other it is a question of finding a solution which permits the creat~on of the contact pressure at ~hese points.
However, the great advanta~e of the solutions defined herein-before is that they are compatible with one another.

~07~527 Thus, for example, it is possible to combine the inertial actuating means for the annular rolling surfaces and creating the contact pressure with the members permitting the axial actuation of the conical rolling surfaces with a view to modifying the position of the contact points.
In the same way, it is possible to combine the elastic systems actuating the ann~lar rolling surfaces, with a view to creating the contact pressure, with the mem~ers which axially actuate the conical rolling surfaces. For 10 example, in this case, these members can be of the hydraulic type and comprise tight chambers able to receive a pres-surized fluid.
Moreover, it is possible to combine the systems of ; ramps actuating the conical rolling surfaces, with a view to creating the contact pressure, with the members which axially actuate the annular rolling surfaces with a view to mod~fy~ng the position of the contact points. For example, ~n th~ 8 case, the members can comprise connections by gear trains. However, other permutations and combinations are 20 possible without passing beyond the scope of the present invention.
An explanation is provided here of an apparent duplication of the members comprising the transmission device.
~t wou~d in fact appear that the transmission dev~ce comprises two members ~on the one hand the system crea~ing the contact pressure and on the other the means for modifying the position of the contact points between the rol~ing surfaces) haYing at least in the case of certain embodiments a comparible function, namely that of axially actuating the rolling surfaces of one and/or the other of the members relative to one another. However, in connection with these embodiments it 18 important to note that:
one of these members ~namely the system creating the contact pressure) axially actuates the rolling surfaces of the member in question without in practice displacing them, in such a way as to create the indispensible contact pressure, the action thereof being permanent;
the other, (namely the means for modifying the position of the contact points) modifies the axial position of the rolling surfaces in such a way as to modify the ~l/R2 ratio of the radii of the circles described by the contact points on the rolling surfaces of the second meSmber relative to the radii of the circles described by the contact points or the rolling surfaces of the first member, said means only being used when it is necessary to vary the transmission ratio, so that their action is temporary.
Point 3).
The problem of the mechanical connections occurs repeatedly relative to a transmission device according to the invention.
On the one hand between the coupling means and the second member or the supporting means, on the other between the coupling member and the first member or the second member and finally ~etwee~ the second memSber and the frame or between the second member and the first member so as to lin~ the c> o * r speeds ~a, ~ or at least two of them.

' s~

Moreover, the problem of the mechanical connections is occurring between the auxiliaries of the transmission device or the motor operating the transmission device and the second member (for the supporting means) in order to synchronize the operation of the auxiliaries with those of the transmission device~
~ he problem of the mechanical connections involve different solutions depending on the advantages which it is desired to obtain or depending on the disadvantages which it is desired to avoid. Moreover, different solutions can be envisaged according to the nature of the members which are to be connected or, alternatively, the same solution can ~e used for connecting members of a different type.
a) In order to solve the problem of the mechanical connections, a particularly simple solution can be achieved when the second member is inclined by the constant angle and ! consists of using conical gears of apex S. This solution can be used for different possible embodiments of the trans-mission device.
According to a first embodiment, this mechanical connection, involving conical gear trains of apex S forms the second connection means between the coupling member and the second movable member.
According to a second embodiment which can be used when the first member is mounted so as to rotate relative to the frame at the speed ~ about the first axis, this mechanical connection by conical gear trains o~ apex S is placed ~etween the second member an~ the frame in such a way O O*
as to lin~ the speeds a and ~ .

_ 24 _ According to a third embodiment which can also be used when the first member rotates relative to the frame at speed ~ about the first axis, this mechanical connection by conical gear trains of apex S is located between the first and second members in such a way as to link in rotation O O* O
the speeds ~, ~ , and ~ or at least two of them.
Preferably, the conical gear train comprises two conical gears of apex S one integral in rotation with the second member and the other lin~ed in rotation with one of 10 the following members: the frame, the coupling member, the first member or the supporting means.
b) The problem of connections between the supporting means and the coupling means (noteably constituted by a rotary drive shaft) does not present a difficulty because the slope angle a is fixed. It has already been seen that the supporting m~ans can rotate about the first axis. It is therefore perfectly simple to link them in rotation with the rotary drive shaft specifically mounted in coaxial manner relative to the first axis. This system can also be used for driving 20 the auxiliaries o~ the transmission device or the motor actuating the transmission device.
c) In the same way, the problem of the connections between the coupling member (specifically constituted by a rotary drive sha~t) and the first member (when the latter rotates about the first axis) does not present a difficulty.
It is possib~e to lin~ in rotation, the first mem~er with the drive shaft, which is more particularly mounted in coaxial manner re1ative ~ the ~irs~ axis.

. . .

Point 4).
In order to solve the problem of balancing the forces of the reaction on the bearings supporting the second member, the second member may comprise gyroscopic means for developing a gyroscopic torque which wholly or partly balances the forces applied to the second member by the system creating the contact pressure.
The gyroscopic means which develop a ~yroscopic torque have a direction and an intensity which is sufficient to relieve the stress on the bearings inserted between the supporting means and the second member (~hese bearings permit the latter to ro~ate about its own axis, the second axis, whilst maintaining the latter inclined by a fixed angle a).
As a result, it is possible to lighten the material construc-tion of these bearings and decrese the mechanical losses therein.
It is important to point out here what is meant by the phrase "gy~oscopic means associated with the second member, developing a gyroscopic torque," by referring to the mechanical properties of gyroscopic movements. Inertial phenomena are developed in a solid having a movement about a fixed point, the classic example of a solid having this movement is the gyroscope (this is one of the reasons why the adjective "gyroscopic" has been used to define the mechanical means used~ ~he second member according to the invention is in ~act a solid having a movement about a fixed point S. It has in fact a rotary movement a~out its axis ~ 70527 of revolution (the second axis). This axis has itself a conical rotary movement of apex S about the general axis of the transmission device (the first axis). The axis of the 6econd member (the second axis) describes a cone of apex S about the general axis of the transmission device (the first axis). This cone is generally called "~utation cone."
All the elementary forces of inertia which are developed in the mass of the second member can ~e reduced, by applying the general laws of mechanics to a torque and 10 to a force applied at S.
a) The force applied at S:
In the case where the center of gravity of the ~econd mem~er substantially coincides with the point S, the force applied at S is substantially zero. In the opposite case, the force applied at S is a rotary force located in the plane perpendicular to the general axis of the transmission device (the first axis).
Preferably, according to a secondary feature of the present invention, the center of gravity of the second 20 member is adjacent to point S, in such a way as to eliminate the force applied at S which loads the bearings.
b) The torque:
The torque, which the inventor calls the "gyroscopic torque" or "tor~ue with a gyroscopic origin," by analogy with the terminology applied in the study of gyroscopes can be mathematically characterized by a vector, whose direc-tion is perpendicular to the plane containing the first and second axes. The torque has a tendency to swing the second 1~70S27 member about an axis perpendicular to the plane containing - the first axis and the second axis (but since the slope angle a is fixed, no movement is possible).
Preferably, and according to a subsidiary charac-teristic of the invention which facilitates its realization, the second member is a solid which revolves about the second axis having a transverse plane of symmetry perpendicular at S to the second axis. In the case of this special embodi-ment of the second member, it is possible to calculate, by 1~ applying the conventional laws of the mechanics of solids, the moment of this torque (the modulus of the vector), said moment being given by the following formula:
C 1 = (Jl ~ J3)a2 sin a cos a - J3 (a - ~) sin a In this formula:
Jl and J2 designate the moments of inertia of the second member relative to the second axis and relative to an axis passing through S perpendicular to said second axis;
a (also called ~a" in the present application) designates the slope angle of the second axis relative to 20 the first axis;
~ designates the rotation speed of the second member about the first axis;
~ designates the rotation speed of the second member about the second axis in a reference frame which is fixed relati~e to the frame, whilst ~ , which has been used previously, designates the rotation speed of the second member about the second axis in a reference frame lin~ed to the rotary plane containing the ~irst and second axes, whereby be~ween ~ and ~ the relationship ~ a) is obtained.

- 2~ --" 1070527 This formula gives the intensity of the moment of the gyroscopic torque resulting from all the forces of inertia and relative thereto the following comments are made:
a) it has been described in two parts in such a way as to show in the first part the contribution of inertial effects which can be called "centrifugal." Thus, when a = ~, (when ~ = O), the second part of the expression disappears, only leaving the first part, which is independent 10 of the rotation speed value of the second member about its revolution axis (the second axis).
It should be noted that in general in the trans-mission devices according to the invention (~ = O, in other words a = ~*).
b) The expression of the moment of the gyroscopic torque is an algebraic sum, therefore this couple can, depending on the value of each of the parameters, either tend to apply the second member to the first, or, conversely tend to oppose the second member being supported on the 20 first.
In other words, the different parameters such as th~ shape and mass of the second member tJl, J3), the rotation speed (a, ~) and the conical movement angle a ~or a) must, for each variant, be proportioned so as to obtain a tor~ue hav~ng a direction and an intensity sufficient for ba~ancing the reactive torque produced by the mechanical system creating the contact pressures at points Pl and P2 (linked with the power to be transmitted by the transmission device).

The term "gyroscopic means" is understood to mean all the structural parameters and all the kinematic parameters of the second member which influence the intensity and direction of the gyroscopic torque.
The calculation of the gyroscopic means (i.e. the calculation of the structural and kinematic parameters of the second member~ falls within the scope of the skilled expert. More particularly in the case of certain variants, he can use the formula given hereinbefore. The calculation of the gyroscopic means falls within the scope of the skilled expert provided that, in accordance with one of the main features of the present invention, he has received the instruc-tion to use the gyroscopic torque created by these means in order to balance with a sufficient force in a total or partial manner the reactive torque produced by the mechanical system creating the contact pressures at points Pl and P2.
Point 5).
In ordsr ~o solve the problem of balancing the reactive forces on the frame, the supporting means may comprise inertial means for developing a torque with an inertial origin which serves to wholly or partly balance the forces produced by the system creating the contact pressures on the first member and consequently on the frame.
The inertial means comprise an arrangement and a distribution of the masses forming the ~upporting means.
Before describing in detail several embodiments of the transmission devices forming the ob~ect or objects of the present invention, it would appear necessary to "1~
t ~ ~ ~

~1~7~5;~7 briefly point out that the different members composing the transmission device can be realized or arranged in different ways depending on the complementary problems or subsidiary advantages which it is desired to additionally obtain.
Firstly, the relative positions of the first member and the second member can vary. The first member can be contained within the second member which is then a hollow body. Firstly, the second member can be contained in the first member which on this occasion is hollow. Correlatively, 1~ the revolving rolling surfaces can in turn be concave or convex in a transverse plane.
Secondly, a large variety of rolling surface forms are possible. In the special case where the rolling surfaces are conical (making it unnecessary to vary the slope angle a), these conical rolling surfaces can be mounted on the first member or on the second member.
In the meridian planes ~i.e. in a radial plane passing through the axes of revolution of the rolling surfaces) the generating lines of the rolling surfaces can either be 20 convex rolling su~faces or concave rolling surfaces. The choice of the radii or curvature of the rolling surfaces in the transverse or meridian planes make it possi~e, all things ~eing equal, to obtain different output speed ranges for the same variation amplitude of the ratio Rl~R2, different variation laws of the transmission power as a function of the output speed and transmission devices with different dimensions.
Thirdly, a large diversity of mechanisms creating the contact pressure is canceivable.

1.:

107~527 Fourthly, the coupling members and coupling means can be realized in different ways. They can comprise main drive ~hafts (input shaft or output shaft or vice versa).
The main drive shafts (more generally the coupling members and coupling means) can be linked in rotation respectively either with the first or second members (as regards the coupling member) or the second member or supporting means (as regards the coupling means). It is not indispensible for the coupling means and coupling member to be respectively 10 linked in rotation with the first and second members, so that one (the coupling member) can be linked with the rotary movement of speed ~ of the second member about its own axis (the second axis) and the other (coupling means) can be linked at the speed a of the second member about the first axis.
Fifthly, the first member can either be fixed or can rotate about the first axis.
In the case where the first member rotates about the first axis at speed ~ the general kinematic transmission 20 equation: ' o o o o Rl ~ - + ~a ~ ~B) R2 =
which was defined by the Applicant in the earlier-dated Canadian Patent ~o. 998,857 leads to indefiniteness. Several possi~le speeds ~ correspond to a spePd ~, depending on the values of ~. To remove this indefiniteness and in accordance with the teaching of aforementioned Canadian Patent No. 988,857 various solutions are possib~e.
One solution consists of connecting in rotation the firs~ member to the coupling member (to a main drive 107~527 shaft) and stopping the rotation of the second member O O* O
relative to the frame (~ = 0; ~ = ~) or stopping the rotation of a main drive shaft connected to the second member.
It has already been seen how it is possible to produce the mechanical connections between the second member and the frame or between the second member and a main drive shaft to achieve this result ~e.g. by means of be~el gears or apex S or a flexible transverse member).
Another solution consists of connecting at least two of the speeds (a, ~ , ~) by means of mechanical connections.
O O* O
Thus, the speeds a, ~ , w are interconnected by two equation systems. On the one hand, the general ~inematic transmission equation:
o o o o Rl ~ a ~ = 0 and on the other hand the equation due to the mechanical connection which can be of the type:
O O* O
F t~, ~, ~) = O
in the case of an epicyclic connection for example or of the type: r o o*
g (~, B ) = 0 or even of the type:
O O
h (a, ~) = 0 O O*
) = O
This system of equations makes it possi~e to determine the output speed of the transmission device as a function of the input speed for a predetermined ~alue of ratio R~/R2. Thus, only a single output speed corresponds to one input speed.

1~7VSZ7 The mechanical connections linking the speeds O O* O
provide particular advantages. As has been seen, the gyroscopic balancing torque varies as a function of the speeds of the second member about the second axis and of the second axis about the first axis. Therefore, the mechanical connections make it possible to modify the evolution of the gyroscopic torque as a function of the output speed. ~hus, it is possible to correlatively obtain output torques which are better adapted to the different cases of utilization 10 (constant torques, etc.).
The mechanical connections connecting the speeds O O* O
, ~ , ~ in the same way as the mechanical connections linking the first and second members, as well as the supporting means to the coupling members and the coupling means (to the main drive shaft: input or output shafts of the transmission device) can be formed in different ways, e.g. by means of bevel gear trains of apex S or by means of a flexible transverse mem~er~ or by means of sliding articulations mounted at the extension end integral with the second member.
It is pointed out that the expression "linked in rotation" used in the present description and in the claims, relates to identical angular velocities or in a constant given ratio or in a variable given ratio, whilst the expres-sion "integral in rotation" relates to identical speeds.
The various em~odiments of transmission devices according to the invention will now be described in greater detail relative to non-limitative examples and with reference to the drawings which show:

. . , ~7~5Z7 Fig. l is a longitudinal sectional view through a plane passing through the first and second axes of a first variant, the system creating the contact pressure and actuating the rolling surfaces comprising an elastic system.
Fig. la is a cross-sectional view through the plane a-a of the variant shown in Fig. l.
Fig. 2 is a longitudinal sectional view through a plane passing through the first and second axes in a second variant comprising the system creating the contact pressure, 10 having an inertial origin.
Fig. 3 is a force diagram illustrating the opera-tion of the inertial system described with reference to Fig.
2.
Fig. 4 is a longitudinal sectional view through a plane passing through the first and second axes of a third ~ariant having a system creating the contact pressure com-prising a system of helical ramps, whereby in this variant the annular rings on which are pro~ided the rolling surfaces are posltioned externally by a gear system.
Fig. 4a'is a cross-sectional view through the plane b-b of the variant shown in Fig. 4.
Fig. 5 is a longitudinal sectional view through a plane passing through the first and second axes of a fourth variant having a system creating the contact pressure com-prising a system of he~ical ramps, whereby in this variant, the annu~ar rings on which the rolling sur~aces are provided are positioned externa~1y through the combination of a hydraulic system and a gear train~

Fig. 5a is a partial perspective view of the manipulating member of the variant of Fig. 5.
Fig. 6 is a longitudinal sectional view through the plane passing through the first and second axes of a variant of the type described with reference to Figs. 2 and 3, whereby in the case of this variant, the first biconical mem~er is fixed.
~ ig. 7 is a longitudinal sectional view through the plane passing through the first and second axes of a variant 10 of the type described with reference to Fig. 4 and 5, whereby in the case of this varian~, the second member carries the biconical rolling surface.
Fig. 7a is a detailed perspective view of the means for modifying the position of the contact points Pl and P2 in the case of the variants shown in Fig. 7.
Figs. 1 and la will now be described which respec-t~vely show a longitudinal sectional view and a cross-sectional view of a first variant of a transmission device according to the invention.
This transmission device comprises a fixed frame having at either end two substantially planar sides Al and A2 ~oined by a casingA3, which has a generally cylindrical shape.
A first member 2 and a second mem~er ~ are mounted so as to rotate on said frame via bearings.
The first mem~er 2 rotates a~out a first axis 7 which is the longitudina~ axis of the transmission device, being fixed relative to the frame A. The first member comprises two halves 4 and 5, having two conical rolling surfaces 8 and ~f ~

1070S~7 9. These two halves are mounted on a shaft 11 (output shaft) which is coaxial to the first axis 7 and are axially movable relative to oné another in accordance with the longi-tudinal direction of the first axis 7. Keys 22a and 22b interlock in rotation the two halves 4 and 5 and the shaft 11 .
~ etween the inner wall of halves 4 and 5 and the outer surface of shaftll are provided two annular chambers 14a and 14b, which communicate with the outside by pipes 10 17a, 17b and 15 provided to this end in the mass of shaft -11. A cylindrical groove 18 on the surface of shaft 11 makes it possible to introduce a pressurized fluid into the chambers 14a and 14b when shaft 11 rotates on itself about the first axis 6. Gaskets 21a, 21b, 21c, 21d, 21e and 21f ensure the sealin~ of the system of annular chambers and the supply pipes 4 of said annular chambers. The introduction of a pressurized fluid into the annular chambers has the effect of simultaneously axially displacing the two halves 4 and 5 and the rolling surfaces 8 and 9 by moving them ~0 apart. The functson of said manipulating members of the rolling surfaces 8 and 9 of first member 2 will be shown hereinafter.
The frustum-shaped rolling surfaces 8 and 9 are of revolution about the first axis 7 and are disposed symme-trically on either side o~ a plane 10 which is perpendicular to the first àxis 7 at a point S of said axis. The large bases of each of the two truncated cones face one another.
Shaft 11 is supported by the frame at each of its ends by a system of bearings comprising a first series of roller bearings la and lb coaxial to the first axis 7. ~n 1~7~5Z7 order to facilitate the assembly of the first mem~er and the shaft 11 supporting the same, the end of shaft 11 is disassemblable ~y means of a system of rings 23a, 23b and the bolt 24.
A support 13 is mounted so as to rotate about the first axis 7 by means of a system of bearings 25a and 25b inserted between the frame A (sides Al and A2) and the support 13. The ~earings la and lb mentioned herein~efore are them-selves mounted within the support 13 in the transverse plane of bearings 2~a and 25b at each of the ends of the trans-mission device, in such a way that the first mem~er 2 can rotate relative to support 13, which can itself rotate relative to frame A.
The substantially cylindrical support 13 is inclined relative to a lorgitudinal axis 7 of the transmission device.
It i6 intended to sup~ort the second member 3 via needle ball bearings 26a, 26~, and 26c. This latter bearing serves to axially position the second member 3 relative to the support 13.
The second member 3 is a substantially cylindrical solid of revolution and rotates relative to the support 13 about a second axis 12 passing through the pcint S of the first axis 7 and inclined by a constant fixed angle _ (also called a) relati~e to the latter. In the case of this embodiment, the half-angle at the apex of the cone frustums forming the rolling surfaces of the first mem~er is slight~y smaller than the a~o~e-defined slope angle _. The significance of this will be shown hereinafter with reference to the description of the operation of the transmission device.

~07~527 The second member 3 co~prises two rolling surfaces 19 and 20 which are of revolution about the second axis 12 and are symmetrically disposed on either side of a plane 16 perpendicular to said second axis at point S. These rolling surfaces are formed on two annular rings 27 and 28 which are axially movable relative to one another, in accordance with the longitudinal direction of the second axis 12 within the cylindrical body 3a of the second member, but they are integral in rotation with the second member 3.
A mechanical system comprising a plurality of coil springs 29 axially actuates two rolling surfaces 19 and 20 of the second member in such a way as to apply the latter with a sufficient force at two contact points Pl and P2 against the rolling surfaces 8 and 9 of the first member 2.
These springs are fitted along the inner wall of the second member 3 and supported on the one hand on the flanges 30a and 3Ob located at the two ends of the second member 3 and on the other on each of the annular rings. The exact function of this spring system will be described hereinafter.
A bevel gear 31 of apex S is integral in rotation with the second member 3 and cooperates with a bevel gear 32 of apex S integral with the casing A3 of the frame. A
main drive shaft 33 ~input shaft) is integral in rotation with support 13, said shaft 33 being coaxial to axis 7.
The operation of this embodiment of a transmission device according to the invention will now be descri~ed.
The biconical rolling surfaces are in rollin~
frictional contact at Pl and P2 with the rolling surfaces 19 and 20 of the second member. The speci~ic contact pressure ~.~.,' 107~527 is created by the spring system. These springs 29 and the ha~f-angle at the apex of the frustom-shaped rolling surfaces are calculated to create the normal pressure FN sufficient to transmit the input torque, without any slipping of the races relative to one another. Under the action of the input torque applied to the input shaft 33, rolling surfaces l9 ~-and 20 are rotated on the one hand at the speed ~ about their own axis (the second axis) and on the other are given a conical movement of apex S about the first axis 7 at lO speed a.
The above-defined speeds ~ , and speed ~ of the first member about axis 7 are interconnected by a kinematic relationship dependent on the geometry of the rolling surfaces and which is as follows:
~ " - a - ~* --In this equation, Rl and ~ designate the radius Rl of the circle described ~y one of the contact points on the rolling surface in question of the second member and the radius R2 of the circle described by one of the contact points on the 20 considered rolling surface of the first member.
In the case of the present embodiment, the bevel gears 31 and 32 of apex S, which are respectively integral with the second member 3 and the frame, have the effect of lin~ing in rotation the speeds ~ and ~ in such a way that the ~atter are in a constant ratio. Conse~uent7y, ~or an input speed a there is only a single output speed ~ at which the output shaft ll of ~he transmission de~ce can ~e driven.

107~5Z7 The metallic masses of the second member 3 are distributed in such a way that the center of gravity of the second member coincides with the point S of the first and second axes and the main moments of inertia ~1 and J3 of the second member have values related to the speeds a and B and the slope angle a (also called a) in such a way that a gyroscopic tor~ue is developed havinq a direction and intensity sufficient for wholly or partly balancing the reactive torque associated with the normal forces FN.
Thus, the bearings 26a, 26b and 26c which support the second member, only receive relatively low or zero radial forces during operation.
Furthermore, as a result of the symmetrical arrange-ment of the rolling surfaces, bearings la, lb, 25a and 25b supporting the main drive shafts receive no axial reaction.
The way in which the input speed ratio can ~e varied by modifying the ratio Rl and R2 will now be described.
By injecting a pressurized fluid into the chambers 14a and 14b, it is possible to displace the rollinq surfaces 20 8 and 9, by respectively moving them away from plane 10.
In Fig. 1, the rolling surfaces 8 and 9 are shown in their position of maximum spacing. The available transverse spacing between the rolling surfaces 8 and 9 and the cylin-drical body 3a of the seco~d member 3 decreases in propor-tion to the mo~ing apart of the rol7ing surfaces. As the slope angle of the second axis relative to the first axis is significantly greater than the hal~-angl~ at the apex of the frustum-shaped rolling surfaces 8 and 9 the available ~ 41 -107~527 transverse space between the rolling surfaces 8 and 9 and the cylindrical body 3a of the second member 3 increases in the direction of the plane of symmetry 16. Therefore, the axially movable annular rings 27 and 28 on which are provided the rolling surfaces 19 and 20 cannot move back in the direc-tion of plane 16 when the rolling surfaces 8 and 9 are moved away from one another by injecting a pressurized 1uld(rolling surfaces 8 and 9 move back relative to the action of the elastic system 29a and 29b). Therefore, the ratio Rl/~
10 varies, because the radius R2 increases, so that correlatively, bearing in mind that the kinematic equation mentioned here-inbefore the speed ratios ~ and ~ vary.
Conversely, when the fluid pressure in the chambers 14a and 14b increases, the rolling surfaces 8 and 9 move towards one another and towards plane 10. They are in fact actuated by the spring system 29a and 29b via annular rings 27 and 28. They are actuated by the spring system whilst the fluid pressure in the chambers does not balance the force exerted by the elastic system. As a result of the reversible 20 displacement of tHe rolling surfaces 8 and 9, it is possible to continuously vary in ~ne direction or the other the speed ratio of the transmission device.
With reference to Fig. 2 a second e~bodiment of the transmission device according to the invention will now be described. Fig. 2 shows a longitudinal sectional view through a plane passing through the first ana second axes of the transmission device comprising a mechanical system creating the inertial contact pressure.

- ~2 -10'7~527 Most of the members described with reference to Fig. 1 are shown in this drawing. They carry the same reference numPrals and more particularly it is possible to see frame A, first member 2, second member 3, first axis 7, Qecond axis 12, support 13, rolling surfaces 8 and 9 of the first member and 19 and 20 of the second member, with the constant fixed slope angle a of the second axis relative to the first axis.
A detailed description will only be provided here 10 of those members whose structure differs from that described hereinbefore. This applies more particularly to the geometry of the rolling surfaces 8 and 9 having a generally conical configuration.
In the case of this embodiment, the mechanical system creating the contact pressure and actuating the rolling surfaces has an inertial origin, i.e. the inertial forces which develop in the mass of the annu~ar rings 27 and 28 actuates the latter and applies them against the rolling surfaces 8 and 9. Fig. 3 shows the force diagram 20 illustrating the operation of the mechanical system actuating o~e of the rolling surfaces. As the annular ring 28 is rotated at speed a about the first axis 7, it is subjected to centrifugal forces, whose resultant at Gp (center of gravity of the annular ring }ocated on the second axis 12) is a rotary force Fc ~this force depends on the geometry and mass of the annular ring as well as its speed ~). This ~orce can be broken down into an axia~ component (directed according to the second axis 12~ FCa and a radial component ~' -107~527`
FCr. This axial component FCa has the tendency to displace the annular ring 28 in the direction of arrow F, i.e. to move the ring 28 out of the plane of symmetry 16 of the second member. Therefore, the annular ring is displaced until it iB supported on the rolling surface 9 of the first member, by exerting an adequate pressure to prevent the slipping of the rolling surfaces 9 and 20, in such a way that the rolling surfaces roll on one another without slipping.
It is ~nown that in order to transmit a given input torque, it is necessary to exert a predetermined normal force FN (this normal force FN is obtained by calculation or experimentally from the torque value to be transmitted).
Tt is possible to calculate or draw the profile of the rolling surface 9 of the first member and define the geometry of the annular ring 28 in such a way that each contact point between the rolling surfaces 9 and 20, the normal force created ~y the centrifugal force Fc is equal to the desired normal force FN. Thus, if T is used to designate the tangent at contact point P2 relative to the rolling surface 9 of the first member, said tangent T forms an angle ~a with the second axis 12 which is materialized by drawing at P2 the parallel line and the perpendicular line to the first axis 12.
The axial component FNa (in accordance with the second axis 123 of the nor~al force FN is a function of the a~ove-defined ang~e ~a:
Na N sin ~a _44; _ 1070~Z7 When balanced, this axial component FNa must be equal to the axial component FCa created by the centrifugal force:

ca FNa = Fn x sin ~a Thus, by graphically or numerically solving this equation, it is possible to determine the geometry, the mass of the annular ring and the rotation speed ~, as well as the profile of the rolling surface 9 permitting the creation of the desired normal force ~N~
The operation of the manipulating member permitting the axial position of the rolling surfaces 8 and 9 and the variation of the speed is, in all points identical to that applied with reference to ~ig. 1.
Figs. 4 and 4a will now be described which respec-tively show a longitudinal sectional view through a plane passing through a first and second axes and a cross-sectional view of a third variant having a mechanical system for i actuating the rolling surfaces creating the contact pressure ! comprising helical ramps. These drawings show most of the 20 members described'with reference to Fig. 1 and these carry the same references. A detailed description will be provided hereinafter only of those members having a different structure from those described hereinbefore, more particularly the mechanical actuating system for rolling surfaces ana the manipulating mem~er.
In this em~odiment, the rolling surfaces 8 and 9 are truncated cones, whereof the half-angle at the apex is egual to the slope an~le _ of the second axis relative to 107~527 the first axis. Therefore, the available spacing between the cylindrical body 3a of the second member 3 and the rolling ~urfaces 8 and 9 is constant over the entire length of the rolling surfaces.
The rings are mounted, in a manner to be described hereinafter, in such a way that they can be axially displaced, in accordance with the direction of the second axis in the space defined hereinbefore and are in frictional contact with the rolling surfaces 8 and 9.
The two halves 4 and 5 on which the rolling surfaces 8 and 9 are formed, are movable on shaft 11 by means of helical ramps 40a and 40b having a reverse pitch. It is obvious that on rotating the two halves 4 and ~ relative to the output shaft 11 in an appropriate direction, there is a tendency to move apart hal~es 4 and 5. This has the effect of reducing the space between the rolling surfaces 8 and 9 and the second member 3. Consequently, on rotating the two halves 4 and 5 in an appropriate direction, the rolling surf~ces 8 and 9 are applied against the rolling surfaces 19 and 20 with a sufficient~normal force to transmit the input torque.
A coil spring 40c inserted between the two halves 4 and 5 facilitates the realization of the mechanical system which creates the normal force by pretensioning the rolling surfaces in such a way that they are prevented from sliding on one another on starting or in the case where the output torque is zero.
The annular rings 27 and 28 are mounted so as to s~ide axially within the cylindrical body 3a of the second member having a cylindrical shape internally. They are traversed by threaded rods 41, such as 41a, 41~ a~d 41c having opposite pitches, making it possible to axially displace them (to move them closer or further away). These threaded rods 41 are integral with gears 42, such as 42a, 42b and 42c, moved by a crown gear 43 whose axis is the second axis 12. ~his crown gear 43 is itself integral with a bevel gear 44 of apex S in gear with a further bevel gear 45 of apex S, which rotates about the first axis 7. Bevel gear 45 is integral in rotation with a gear 46 which is in 10 gear with a gear 47, integral with a manipulating lever wh~ch moves about an axis 48, fixed relative to frame A. As a result of this combination of gears, it is possible to control from the outside of the transmission device, the axial position of the annular rings and thus vary the speed ratio of the transmission device (as has already been described with reference to Fig. 1).
A description will now be provided of Fig. 5 which shows a longitudinal sectional view through a plane passing through the first and second axes of a fourth embodiment.
20 In the case of this embodiment, the annular rings, on which are provided the rolling surfaces, are positioned externally "~
by the combination of a hydraulic system and a gear train.
This drawing shows most of the members described with reference to the previous drawings, particularly Figs. 1 and 4 and they carry the same reference numerals.
The half-angle at the apex of the frustums con-stituting the rolling surfaces ~ and ~ is substantia}ly equal to the slope angle of the second axis relative to the first axis.

_ 47 -.'~ , In the case of this embodiment, the mechanical system actuating the rolling surfaces and creating the normal force FN is comparable to that described hereinbefore with reference to Fig. 4. It comprises an annular ring S9 mounted integral in rotation with shaft 40 by means of channels.
Annular ring S9 has on its sides ramps formed by teeth 59a and 59~ which cooperate with ramps having a complementary configuration, also formed by teeth 4a and 5a integral respectively with halves 4 and 5 on which are provided the 10 frustum-shaped rolling surfaces 8 and 9. The inclination of the faces of the teeth is such that the rotation of the two halves 4 and 5 relative to the shaft 8 has the effect of moving them apart and jamming the rolling ~urfaces 8 and 9 against rolling surfaces 19 and 20 of the second member 3.
In the case of this embodiment, the manipulating member which axially positions the annular rings 27 and 28 is of a special type and is shown in perspective in Fig. Sa.
The annular rings are mounted so as to slide within two cylindrical sleeves 53a and 53b, which rotate within 20 the second member 3. These two sleeves 53a and 53b are integral with two conical crown gears of apex S and are syn-chronized in rotation about the second axis 12 via a bevel ~ear S5 of apex S, whose rotation axis located in the plane of symmetry 16 passes through S. This bevel gear 55 is mounted in freely rotatable manner by means o~ a shaft which pivots in the second member and is in gear with two beve? gears SSa and 55~ o~ apex S, integral with the sleeves. The two sleeves have two longitudinal openings 56a and 56b in which 107~27 slide two cylindrical rods 57a and 57b, integral with annular rings 27 and 28. The extensions of the two cylin-drical rods 57a and 57b slide in two other helical ramps 58a and 58b provided in the wall of the second member 3.
The two annular chambers 14a and 14b are indepen-dently supplied with a pressurized fluid by pipes 50a, 50b, 51a, 51~, 52a and 52b of the type described hereinbefore. -~
When the pressure in one of the chambers, e.g. the right-hand chamber 14b is increased, the normal force FN is 10 increased on one side. Therefore, the sleeve 56b tends to rotate more quickly than the second member 3. ~y rotating relative to the second member 3, sleeve 56b, via the opening system causes the axial displacement of the annular ring 28.
As sleeve 56b is synchronized in rotation with sleeve 56a, the latter in turn rota~es relative to the second member whilst axially displacing via the other opening system, the annular ring 27. The profile of the helical openings 58a and 58b of the second member 3 i8 calculated in such a way that the axial movements of the annular rings 27 and 28 20 are in opposite directions. Whilst the pressure difference is maintained between the two annular chambers 14a and 14b, the sleeve~ bring about the axial displacement of the annular rings.
A description will now be provided of Fig. ~ which shows a longitudinal sectional view through a plane passing through the first and second axes of an em~odiment comparable to that describea with reference to Figs. 2 and 3.
Most of the members descri~ed with reference to Figs. 2 and 3 reoccur and carry the same reference numerals.

~0705Z7 In the case of this embodiment, the first biconical member 2 is fixed and integral with frame A via a hollow shaft 11. The casing 60 of the transmission device rotates about the first axis 7 and is integral with a main drive shaft 61. Casing 60 is integral in rotation with a bevel gear 62 of the apex S, of the same type as gear 32 described with reference to Fig. 1. This bevel gear 62 cooperates with other gears 31 of the transmission device, as described hereinbefore.
Support 30 is integral in rotation with a main 10 drive shaft 63 which traverses the hollow shaft 11.
In other words, this embodiment differs from that described relative to Figs. 2 and 3 in that the first member is fixed in rotation. One of the main drive shafts 63 is connected in rotation at the speed ~ of the first member about the first axis 7. ~he other main drive shaft 61 is connected in rotation at the speed ~ of the second member about the second axis 12 via a bevel gear train of apex S.
A description will now be given of Fig. 7 which shows a longitudinal sectional view through a plane passing 20 through the first~and second axes of an embodiment comparable to that described with reference to Figs. 4 and 5.
In this embodiment, the second member carries the conical rolling s~rfaces.
The transmission de~vice has a frame A comprising two flat si~es Al and A2 at each of ~he ends, ~oined by screws to a substantially cylindrical casing A3.
~ he first member 72 comprising two halves 74 and 75 with a generally annular configuration is mounted on the said casing. On these two halves are provided the rolling -- so surfaces 78 and 79 which revolve about a first axis 77 (the longitudinal axis of the transmission device) and ~ymmetrically positioned relative to a plane 80 perpendi-cular to the first axis 7 at a point S of said axis. The two halves move axially within the casing in accordance with the longitudinal direction of the first axis 77. These ; two halves are controlled in axial translation by a manipula-ting member, whose arrangement will be better understood by referring to the detailed view of Fig. 7a to be described 10 hereinafter.
Within the casing is mounted a second member 73 which also comprises two halves 73a and 73b on which are ;~
respectively provided the frustum-shaped rolling surfaces 89 and 90. These two rolling surfaces 8g and 90 revolve about a second axis 82 which coincides with the first axis 77 at a point S. In addition, they are symmetrically arranged on either side of a plane 8~ perpendicular to the 3econd axis at S.
The slope angle a of the second axis, relative 20 to the first axis is constant and substantially equal to the half-angle at the apex of the frustum-shaped rolling surfaces.
These two halves are mounted by means of a system of helical ramps llOa and llOb on a ho~low shaft 81 coaxia~
to the secon~ axis 82 (this system of helical ramps has the same functions as the system of helical ramps describea with reference to Fig. 4).
This shaft 81 and the second member 73 are mounted so as to rotate about the second axis 72 by means of bearings 9~a and 9~ carried at one of the ends by a support 83a which i i ,~ , ~ ~.

is freely rotatable about the first axis 7 and at the other end by a support 83b integral in rotation with a main drive shaft 103.
Support 83a is itself supported by bearings 81a mounted in the side Al of the frame. Support 83b is itself supported by the bearings 81b mounted in the side A2 of the frame.
Sha$t 81 and the second mem~er ?3 which rotate at speed ~ about the second axis 82 are linked in rotation, 10 via a universal joint 7 00 with a main dri~e shaft 104 coaxial to axis 77. This shaft 104 is supported by bearings 105.
The universal joint 100 is located within the hollow shaft f 81.
It can be seen that the members comprising this embodiment of the transmission device according to the invention have similarities with the members described with reference to Figs. 1 to 6. Admittedly, their relative ~ositioning is not the same, but their structures and func-tions are comparable and in fact to stress the similarity, 20 the same terminology as used hereinbefore is employed for describing this new embodiment and in addit7on the reference numerals used show the clear association between this embodi-ment and those described hereinbefore, so that 70 has been added to the reference numerals used in the embodiments of Figs. 1 to 6 when passing from a mem~er, axis, bearing to a member, axis, bearing of the present embodiment.
Therefore, no further detailed description will be provided here of the operation of this em~odiment, because it is comparable to that of the previously descri~ed embodi-ments. However, it is briefly pointed out that the shaft 103 rota~es support 83b at speed a. As a result, due to the fact that the rolling surfaces 78 and 89 on the one hand and 79 and 90 on the other are respectively maintained supported against one another at the two points Pl and P2, the second member 73 rolls against the first member 72 O*
by rotating on itself at the speed ~ about the second axis.
Therefore, the main drive shaft 104, lin~ed in rotation with the second member, is driven.
In the same way as in certain of the embodiments already described, the normal force exerting the specific frictional contact pressure at Pl and P2 is created by the ?
system of helical ramps. In order to facilitate the operation of the helical ramps system on starting, a spring 106, inserted ~etween the two frustum-shaped portions 73a and 73b actuates the rolling su~faces 89 and 90 relative to the rolling ~urfaces of the first member in such a way that the rolling surfaces are pretensioned.
In the same way as previously, the geometry and 2~ kinematics of the second member are adapted so as to produce a gyroscopic torque which balances the reactive torque correla-tive to the normal forces exerted at P1 and P2. This arrangeme~t reduces the mechanical stresses, particular}y on the bearings, which lightens them or reduces wear thereto.
The manipulating mem~er which axially moves the ro~ling surfaces 78 and 79 of the first member wil} now be described with reference to the detailed ~iew of Figs. 7a.
This perspective view shows the cylindrical casing of A3, _ s3 -the first axis 77, the two halves 74 and 7~ of the first member having an annular configuration on ~ihich are formed the rolling surfaces 78 and 79 which revolve about the first axis 77. Cylindrical pins 74a and 75a are respectively integral with the two halves 74 and 75. These two pins slide in a longitudinal opening 115 of the casing and cooperate with a system o~ helical ramps 116a and 116b of opposite pitch, provided in a sleeve 117 and 118, made in two parts in order to facilitate machining of the ramp. The sleeve 10 117 and ~18 is co~,xial to the casing and rotates about the first axis 7. It is obvious that on rotating the sleeve a~out the axis 77, rolling surfaces 78 and 79 are moved away from one another to a greater or lesser extent in accordance wi.h the directi of the first axis 77.

," ~

Claims (20)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS;

1. In a transmission device having a frame, drive input means, and drive output means, means interconnecting said input and output means comprising: a first element on a first axis fixed in the frame and having rolling surfaces of revolution about said first axis, one such rolling surface on each side of a first plane perpendicular to said first axis at a point of axes intersection; a second element on a second axis intersecting said first axis at said point of axes intersection and having concentric journal and rolling surfaces of revolution about said second axis, the rolling surfaces of said second element being disposed one on each side of a second plane passing through said point of axes intersection and perpendicular to said second axes intersection and perpendicular to said second axis; support means rotatable on said first axis and journalled with said journal surfaces to support said second element for movement in a biconical path circumferentially of said first axis, the apex of said biconical path being coincident with said point of axes intersection; the respective rolling surfaces on said first and second elements being in rolling frictional engagement at two points of contact in a third plane containing said first and second axes and located one on each side of said first plane; the rolling surfaces of at least one of said elements being defined by generatrices inclined oppositely with respect to the axis of revolution thereof and symmetrically with respect to said point of axes intersection, thereby to provide in the respective rolling surfaces of said first and second elements a variable ratio of rolling surface radii at said points of contact for variation in the spacing of said points of contact from said point of axes intersection; and means for forcing said respective rolling surfaces on said first and second elements into rolling friction engagement with each other at said two points.

2. Transmission device according to claim 1 wherein the means for forcing the rolling surfaces said elements against each other includes a resilient system effective along the second axis on the rolling surfaces of revolution of the second element.

3. Transmission device according to claim 1 wherein the means for forcing the rolling surfaces of said elements against each other includes means to develop forces of inertia effective along the second axis on the rolling surfaces of revolution of the second element.

4. Transmission device according to claim 1 wherein the means for forcing the rolling surfaces of said elements against each other includes a system of ramps effective along the first axis on the rolling surfaces of revolution of the first element.

5. Transmission device according to claim 1 wherein the means for forcing the rolling surfaces of said elements against each other includes a system of ramps effective along the second axis on the rolling surfaces of revolution of the second element.

6. Transmission device according to one of claims 1, 3 or 4 wherein the means for the variation of the speed ratio includes a pressure fluid system effective along the first axis on the rolling surfaces of revolution of the first element.

7. Transmission device according to one of claims 1, 3 or 4 wherein the means for the variation of the speed ratio includes a gear transmission effective along the second axis on the rolling surfaces of revolution of the second element.

8. Transmission device according to one of claims 1, 3 or 4 wherein the means for the variation of the speed ratio includes a forced guiding system provided with pins and slots effective along the first axis on the rolling surfaces of revolution of the first element.

9. Transmission device according to one of claims 1, 3 or 4 wherein the means for the variation of the speed ratio includes pressure fluid system effective on the rolling surfaces of revolution of the first element and a gear transmission and a forced guiding system provided with pins and slots effective along the second axis on the rolling surfaces of revolution of the second element.

10. Transmission device according to claim 3 characterized in that the rolling surfaces of revolution of the first element are conical and the rolling surfaces of revolution of the second element are annular and that the apex half-angle of the conical rolling surfaces is smaller than the angle between the first and second axes.

11. Transmission device according to claim 2 wherein the resilient system is provided with two helical springs supported respectively at one side on the second element and at other side on the rolling surfaces of revolution of the second element, said rolling surfaces of the second element being axially movable.

12. Transmission device according to claim 3 wherein the rolling sur-faces of revolution of the first element are cone-like and the rolling sur-faces of revolution of the second are annular.

13. Transmission device according to claim 4 wherein the rolling surfaces of revolution of the first element are conical and the rolling surfaces of revolution of the second element are annular and that the apex half-angle of each conical rolling surfaces of revolution is equal to the angle between the first and second axes.

14. Transmission device according to claim 13 wherein the half parts comprising the rolling surfaces of revolution of the first element are screwed by means of helical ramps of opposite slope on a shaft and wherein the two half parts are connected with each other by a helical spring.

15. The apparatus recited in claim 1 wherein said means to support said second element is journalled in the frame for rotation on said first axis and journalled with said second element for relative rotation of said second element and said support means about said second axis.

16. The apparatus recited in claim 15 wherein said means to support said second element is a torque transmitting member having opposite ends journalled in the frame on said first axis and a tube-like section extending between said opposite ends.

17. The apparatus recited in claim 16 wherein said tube-like section is concentric with said second axis and journalled directly with said second element on opposite sides of said second plane.

18. The apparatus recited in claim 17 wherein said second element includes exterior journal surfaces concentric with said second axis and wherein the interior of said tube-like section is journalled with said exterior journal surfaces.

19. The apparatus recited in claim 16 wherein said tube-like section extends radially between said first and second elements and is formed having diametrically opposite, axially spaced openings to enable said rolling sur-faces to engage at said two points of contact.

20. The apparatus recited in claim 19 wherein said second element includes interior journal surfaces concentric with said second axis and where-in said means to support said second element extends within and is journalled with said interior journal surfaces.