Tourbillon with two oscillators in one single cage

Abstract

A horological Tourbillon comprising A) a cage CC rotating around an axis (ZC), divided in two half-cages (1a,b) by a medial plane (RC) perpendicular to the rotation axis (ZC); a double tourbillon (TD) with two regulation systems each made of an oscillator (OSa,b), a lever and it's escapement mobile (MEa,b), installed in their respective half-cage (1a, 1b); the two regulation systems being made of identical elements but organized in an opposite configuration and installed in each half-cage (1a, 1b) symmetrically relatively to the medial plan (RC) so that, in the medial plane, the rotation direction of the two escapement mobiles (MEa,b) are identical; each regulation system has a compensating wheel (RFa,b) that meshes with its escapement mobile (MEa,b); B) a differential (D) made of: two outputs S (a,b) each meshing into a compensating wheel (RFa,b), thus creating a position compensation; one input pinion (ED) linked to the horological mechanism (MH); C) one linkage (EC) between the horological mechanism (MH) and the cage (CC) that allows the cage to rotate around its axis (ZC).

Claims

1. A horological tourbillon comprising: A) a cage rotating around an axis, divided in two half-cages by a medial plane perpendicular to the rotation axis; a double tourbillon with two regulation systems each made of an oscillator, a lever and an escapement mobile, installed in their respective half-cage; the two regulation systems being identical but organized in an opposite configuration and installed in each half-cage symmetrically relative to the medial plane so that, in the medial plane, the rotation direction of the two escapement mobiles are identical; each regulation system has a compensating wheel that meshes with the corresponding escapement mobile; B) a differential made of: two outputs each meshing into the compensating wheel, thus creating a position compensation; one input pinion linked to a horological mechanism; C) one linkage between the horological mechanism and the cage that allows the cage to rotate around the axis of the cage.

2. The horological tourbillon according to the claim 1, characterized in a way so that: axes of the oscillators are superimposed on one principal axis which is the axis of the cage; the oscillators and their constitutive elements are identical or identical within a planar symmetry; the escapement mobiles and the levers of the two oscillators are identical, or identical within a planar symmetry.

3. The horological tourbillon according to the claim 1, characterized in a way so that: the oscillators are fitted with a flat spiral hairspring or a Breguet spiral hairspring.

4. The horological tourbillon according to the claim 1, characterized in a way so that: the two oscillators are installed head-to-toe, one oscillator being above the medial plane and the other being below; the plane of the corresponding escapement mobile and lever sits above the plane of the corresponding balance, and the plane of the other escapement sits below the plane of the corresponding balance, and both spiral hairsprings are contained in the space circumscribed by balance rims.

5. The horological tourbillon according to the claim 1, characterized in a way so that: the escapement components are installed according to an axial symmetry around the cage axis; pivoting axes of the escapement mobiles are parallel to the cage axis and diametrically opposed relatively to the cage axis; the pivoting axes of the levers are parallel to the cage axis and diametrically opposed relatively to the cage axis.

6. The horological tourbillon according to the claim 1, characterized in a way so that: the cage is made of a cage wheel being the medial plane with a half-cage on each side of this plane, each half-cage being made of plates and bridges, each escapement mobile protruding from their half-cages to they can mesh with the corresponding compensation wheel, which is aligned with the cage axis, and the cage wheel has a wheel belt gearing so it can be set in motion by the horological mechanism.

7. The horological tourbillon according to the claim 6, characterized in a way so that: the differential is a differential with flat gearing made of: a frame that rotates around an axis, two output mobiles rotating around and linked together by at least one pair of satellites installed head-to-toe, each satellite having two pinions carried by one single axle, the two satellites in a pair meshing together via homologous ones of the pinions, and via another of the pinions, one and the other meshing with the output mobile.

8. The horological tourbillon according to the claim 1, characterized in a way so that: the double tourbillon also having the axis of the cage, where the axis of the double tourbillon and the axis of the differential are parallel.

9. The horological tourbillon according to the claim 7, characterized in a way so that: the frame of the differential comprises a frame base carrying two pivots aligned on its axis, one of these pivots being fitted with the input pinion, the frame base carries two plates, each having four pivoting points in which the satellites are installed.

10. The horological tourbillon according to the claim 7, characterized in a way so that: each satellite is made of a long pinion and one short pinion, the satellites in each satellite pair being combined head-to-toe with parallel axes, the satellite pairs being installed following a 180° axial symmetry around the differential axis, the long pinion of one satellite is cut so that it can mesh simultaneously with the output pinion of the output mobile and the short pinion of the other satellite of this satellite pair, the long pinion of each satellite pair meshing on a fraction of its length with the output pinion of the output mobile and on another fraction of its length with the short pinion of the other satellite in the same pair, this is made so that no output pinion meshes with a short pinion.

11. The horological tourbillon according to the claim 9, characterized in a way so that: the base of the frame of the differential has side grooves on its equator so the cage wheel belt gearing of the cage wheel can pass, it helps reducing the encumbrance on the equatorial plane, as all the satellites of the differential have a naked axle portion on their lengths to minimize the distance between the axis of the tourbillon and the axis of the differential.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The present invention will be described hereafter in a more detailed fashion using various realization modes shown in (annexed) schematics in which:

(2) FIG. 1 general schematic of a horological tourbillon comprising two oscillators following the invention,

(3) FIG. 2 isometric perspective view of one realization mode comprising a device with two oscillators in one tourbillon cage and a differential feeding the two compensation wheels,

(4) FIG. 3 isometric perspective view of the bridgeworks of the top half-cage of the tourbillon,

(5) FIG. 4 isometric perspective view on one of the tourbillon's escapement and the corresponding escapement,

(6) FIG. 5 top view of the top and bottom regulatory systems showing the symmetry of the elements following the cage axis,

(7) FIG. 6 isometric perspective view of the tourbillon in FIG. 2, highlighting the elements of the escapement in the cage,

(8) FIG. 7 perspective view of the tourbillon according to the invention,

(9) FIG. 8 side view showing the structure of the complete cage, particularly the spirals,

(10) FIG. 9 cut view of the functional elements of the cage,

(11) FIG. 10 isometric perspective view of the differential and the wheel that meshes with the differential input pinion,

(12) FIG. 11 isometric perspective view of the differential without its frame,

(13) FIG. 12 simplified schematics of the differential, without its frame,

(14) FIG. 13 side view of the differential without its frame.

DESCRIPTION OF THE REALIZATION MODES

(15) FIG. 1 is a general schematic of the horological tourbillon according to the invention, comprising a double tourbillon TD linked to the watch mechanism MH by a differential D. The differential's input pinion ED is linked to the watch mechanism MH and the differential's outputs Sa, Sb are linked to the two compensation wheels feeding the escapements of the double tourbillon TD.

(16) According to the horological tradition the function of the mechanism will be described from the source of the power to the oscillator. As a result the description of the relationship with the differential D is the opposite of some terminologies regarding the differential outputs.

(17) The speed of the horological mechanism MH is dictated by the regulation system made of the double tourbillon TD and it's two combined oscillators. The two oscillators have a frequency that is identical in theory, but necessarily different practically, which implies that this difference needs to be compensated to void the mechanism stoppage. The speed co dictated by the double tourbillon TD is the speed average between the speed ω.sub.1=(ω+δω) and ω.sub.2=(ω−δω) of respectively the two oscillators OSa,b since the differential frame will rotate at a speed (ω.sub.1+ω.sub.2)/2=ω.

(18) The horological tourbillon T according to the invention comprises the double tourbillon TD itself made of a cage CC rotating around the axis ZG, and led by the horological mechanism MH by a gear train linked to the cage belt wheel EC of the cage CC.

(19) The cage belt wheel RC defines the cage medial plane CC. On each side of this plane is installed an oscillator OSa, OSb, respectively. These oscillators are constructed and regulated so that their frequencies are as close as possible to each other, However the two oscillators frequencies can never be completely identical.

(20) This slight discrepancy around the average frequency is taken into account by the differential. We will name ω.sub.1=(ω+δω) the speed of one of the oscillators, and ω.sub.2=(ω−δω) the speed of the other. This frequency difference is being translated by a shift in the speed of the compensation wheels, which in turn affect the speed of the differential outputs.

(21) The average of those two speeds is necessarily the speed co dictated by the regulation system to the horological mechanism MH.

(22) Each oscillator OSa, OSb is fed by an escapement mobile MEa,b carried by the cage CC, itself being fed by the compensation wheel RFa, RFb, each being linked to one of the two differential D outputs through an intermediate wheel ERFa, ERFb, respectively.

(23) The gearing between an escapement mobile Mea,b and the corresponding compensation wheel RFa,b is not detailed, given that this structure clearly appears in FIG. 1.

(24) In order to simplify the drawing, the escapement mobiles MEa and MEb do not enter in the cage CC alongside the axis ZC, but are rather shown on the sides of the cage CC. The compensation wheels RFa, RFb are coaxial to the CC cage axis ZC. This does not modify the linkage between the escapement mobiles MEa, MEb to their corresponding compensation wheel RFa, RFb.

(25) The differential D is composed of a frame CH set in motion around it's axis ZD, and carry the output mobiles Sa, Sb each carrying an output pinion Pa, Pb coaxially to ZD. The two output pinions Pa, Pb are linked by two satellites STa, STb carried by the differential frame CH. The satellites reverse the rotation motion of the two pinions Pa, Pb according to the conventional function of a differential.

(26) In the case of the schematics in FIG. 1, the differential D has gearings that are flat, not conical. The traditional conical satellite role is replaced by a pair of flat satellite gears that reverse the motion.

(27) Each satellite STa, STb is made of two pinions (ST1a long, ST2a short) and (ST1a long, ST2a short) each on a single axis ASa, ASb carried by the frame CH. the long pinions ST1a, ST1b respectively mesh with the corresponding output pinion Pa, Pb, the short pinions ST2a, ST2b respectively mesh with the opposite satellite long pinion ST1b, ST1a.

(28) The number of teeth for the pinions ST1a . . . ST2b being the same, the combination of the two satellites STa and STb reverses the transmitted motion from one satellite to the other. As a result when the frame CH rotates with speed co the outputs rotate at a speed +/−δω relatively to the frame.

(29) The outputs Sa, Sb receive the motion ω.sub.1, ω.sub.2 from the two oscillators and convey them to the two pinions Pa, Pb; because each pair of satellites is carried by the frame CH, the frame is set in rotation around the axis ZD at the average speed ω=(ω.sub.1+ω.sub.2)/2. The relative differences in rotation speed +δω and −δω from the two pinions Pa, Pb ends up being compensated.

(30) The horological tourbillon TD dictates its rotation speed co to the rest of the mechanism MH.

(31) For the sake of clarity of FIG. 1, the representation of the axes ASa and ASb are tilted to show the angular shift of the two satellites Sa, Sb around the axis ZD in the frame CH. In reality one of the satellite STa is in front the plane of FIG. 1, and the satellite ST bis behind this plane.

(32) In order to equally transmit the pressure efforts to the output pinions Pa, Pb, the satellite pair STa, STb is supplemented by a second identical pair ST′a, ST′b, symmetrically placed according to the axis ZD.

(33) FIGS. 2 and 3 show a mode of realization of the tourbillon T whose detailed components are differentiated in the figures by numerical references. As a reminder, general references from FIG. 1 will be added.

(34) To simplify the representation of the horological tourbillon T, given the identity of shapes and symmetries, the components will bear their numerical references appended by the suffix (a) or (b).

(35) FIG. 2 shows an isometric perspective ensemble view of one mode of realization of the horological tourbillon, comprising a double tourbillon TD linked to the horological mechanism by a differential 5.

(36) The different parts of the double tourbillon TD will be described separately in FIGS. 3-13.

(37) FIG. 3 shows the bridgeworks of a half-cage carried by the cage wheel 10, shared by the two half-cages 1a, 1b and defining the medial plane RC of the cage 1, perpendicular to the cage rotation axis ZC.

(38) The wheel 10 has a belt toothing 101 for its gearing. It carries the escapement plate 11a using the pillars 161. The escapement plate 11a carries the escapement bridge 13a.

(39) The lever bridge 12a is carried by the escapement plate 11a and the cage pivot 14a is mounted on the lever bridge 12a.

(40) The cage elements are mounted in a rigid way. The escapement plates 11a,b are carried by the shared wheel 10 via pillars 16. The lever and escapement bridges (respectively 12a,b and 13a,b) are mounted on the escapement plate 11a,b via pillars 16. The cage pivots 14a,b are mounted on the lever bridges 12a,b.

(41) The bridgework shown on FIG. 3 is reused symmetrically according to the previously mentioned situation, and receives the components of the second oscillator OSb.

(42) FIG. 4 shows the oscillator 4a which is on top according to the representation position. It is installed in it's half-cage shown on FIG. 3. Separately, this oscillator 4a displays the usual structure of an oscillator: a balance wheel 41a, mounted on an axis 40a which conical part carries a double plateau 43a fitted with an ellipsis 44a.

(43) A collet 42a carrying a spiral 45a is fitted on the cylindrical portion of the axis 40a. The spiral 45a comprises an Archimedean flat spiral portion 450a and a Breguet overcoil 451a. The terminal curve is attached to a stud 46a held in a stud holder 15, linked to the cage wheel structure 10 (FIGS. 5 and 6).

(44) The lever 3a is made of a base 30a, an entry pallet 31a and exit pallet 32a. It ends by the fork 33a working with the ellipsis 44a from the oscillator 4a.

(45) FIG. 5 is a planar view of the combination of the two oscillators 4a, 4b (as is oscillator 4a in FIG. 4) on the same axis ZC (FIG. 1) on their respective sides of the plane defined by the shared, unshown, cage wheel 10. The two oscillators 4a, 4b are diametrically opposite and rotate in the same direction, as can be deducted simply by looking at the teeth of the escape wheels 21a, 21b.

(46) Geometrically, in this configuration, the escapements must be identical by a mirror reflection. The functions of the swiss lever escapement is well known and will not be further described here.

(47) The oscillators 4a, 4b are necessarily identical, and are assembled in head-to-toe configuration. Their components (collet 44a,b and spiral 45a,b) are also geometrically identical and assembled the same way. When observed along the cage axis 5 they appear to be identical according to a planar symmetry. Their motions are most of the time synchronous and opposite from each other. The rest of the time, they exist in a wide range of transient behaviors during which the frequencies are in the process of balancing each other out—i.e. the motions are not completely synchronous.

(48) In order to balance the cage, the axes of the two escapement mobiles 2a, 2b are parallel to the cage axis ZC and placed in diametral opposition relatively to that axis. So are the axes of the two levers 3a, 3b. This placement can be seen in FIG. 5.

(49) The escapement mobiles 2a,b are made of the escapement pinions 20a,b and escapement wheels 21a,b. Each pinion 20a,b rotates around a compensation wheel 50a,b. In order to keep the system functioning during asynchronous periods, the two compensation wheels are linked to the differential via transmission mobiles.

(50) FIG. 6 is a perspective view of the elements in FIG. 5 supplemented by to the two compensation wheels 50a,b and their relationship with the escapement pinions. One can infer the meshing of the wheels 50a with the escapement p inion 20a. Only the levels of the compensation wheels 50a, 50b has been represented. The meshing with the transmission mobiles has been omitted.

(51) FIG. 7 shows the combination of the two oscillators 4a, 4b inside the bridgeworks shown in FIG. 3, completed by the other homologous bridgework under the cage wheel 10. This constitutes the cage 1 of the tourbillon TD.

(52) The representation is limited to the bridgeworks on the double cage 1a, 1b, the escapements (escapement mobiles 2a,b, levers 3a,b), the oscillators 4a,b. The cage 1 is set in motion by the cage belt gearing 101.

(53) The fixed elements of the cage 1 are a cage wheel 10, shared by the two half-cages 1a, 1b as their base. The escapement plates 11a,b carry the levers 3a,b and the escapement mobiles 2a,b. The lever 3a,b is positioned by the lever bridge 12a,b, which also holds the oscillators 4a,b. The escapement bridge 13a,b holds the escapement mobiles 2a,b.

(54) The cage 1 is held in position by it's pivots 14a,b (FIG. 3).

(55) The layered organization of the cage 1 is highlighted in the sideview in FIG. 8 and the side cut view in FIG. 9 showing the symmetrical disposition of the components relatively to the rotation axis ZC, as well as the two studs 46a, 46b on the shared, double stud holder 15.

(56) The differential 5, shown in FIGS. 1 and 11 is made of a frame 52, itself made of a base 521 in which are fitted two pivots 526. Two plates 522 carrying the pivoting points 523 of the satellites 55 are attached to the base 521 by two screws 524 each. The pivots 526 define the differential rotation axis ZD and are used as rotation axles for the two output mobiles 53a,b. The base 521 has two lateral grooves 525 to allow the differential to be mounted closer to the cage TD and let the cage gear 10 pass inside the differential inscribed volume, so that the differential frame 52 and the cage 1 can rotate freely around their axis respectively ZD, ZC.

(57) The frame 52 carries the input pinion 54 that is led by the wheel 56, itself linked to the horological mechanism MH.

(58) The output mobiles 53a,b are each made of a tubular pinion 531, and an output wheel 532 pressed on the pinion.

(59) The satellites 55 are assembled in pairs, positioned head-to-toe, and the pairs are installed in the frame 52 in diametral opposition relatively to the axis ZD.

(60) The four satellites 55 are identical.

(61) According to the references in FIG. 11, a satellite 55 is made of a long pinion 551, a short pinion 552, and a axle 553. The two pinions 551 and 552 are flat pinions, with gearing in a plane which is perpendicular to their rotation axis. Their lengths are different so they can be combined and accomplish the inverting function. The satellites mesh with the output pinions 531 as shown in FIGS. 12 and 13.

(62) According the FIGS. 12 and 13, the satellites 55a and 55b in one pair are installed head-to-toe and: the satellite 55a meshes: by the long pinion 551a with the output pinion 531a by the long pinion 551a with the short pinion 552b by the short pinion 552a with the long pinion 551b the satellite 55b meshes: by the long pinion 551b with the output pinion 531b by the long pinion 551b with the short pinion 552a by the short pinion 552b with the long pinion 551a

(63) The axis of the satellites must be located on a cylinder whose central axis is ZD so that the long pinions 551a,b mesh with their respective output pinions 531a,b. Also each long pinion 551 has to mesh with the output pinion 531, and the output pinion 531 must not interact with the short pinion 552. The short pinion must therefore stay over/under the output pinion 531 as shown in FIG. 13.

(64) The possibilities of meshing two gearings at a time between 531, 551, 552, is made possible by the asymmetry in the satellite pinion sizes.

(65) The axes 553a,b of the satellites 55a,b are diametrically opposite relatively to ZD, on a circle centered on this axis. The minimum diameter at the waist of the differential D is defined by this circle, thus the grooves 525 in the frame 52 are deep enough that the frame diameter at this point does not exceed the circle.

(66) The diametrically opposite configuration of the satellite pairs and the transverse orientation of the frame 52 create a cross pattern that is balanced around the axis ZD. This cross disposition is shown in FIGS. 1, 12 and 13.

(67) The FIG. 12 indicates the rotation of the differential's 5 elements:

(68) The output mobiles 53a,b have a speed of ω.sub.1=(ω+δω) and ω.sub.2=(ω−δω) around the axis ZD. These speeds are respectively superior and inferior than the average speed ω=(ω.sub.1+ω.sub.2)/2 according to the function of a differential.

(69) To conclude and sum it up, one needs to notice that the structure of the differential of the realization in FIG. 2 differs from the one in FIG. 1. The FIG. 1 being flat schematics it is impossible to display the axially compact organization of the differential D.

(70) In this mode of realization the frame 52 passes through the output mobiles 53a,b along the axis ZD, and receives the input pinion 54 over one of the two output mobiles.

(71) Going back to the full view in FIG. 2 and the flat schematics of FIG. 1, the differential 5(D) is made of the frame 52(CH) rotating around the axis ZD. Carried by the frame 52(CH) are two output mobiles 53a,b (Sa,b) rotating around the axis ZD. The two output pinions of the output mobiles 53a,b have the same number of teeth, which must be even. The output mobiles 53a,b mesh with the transmission mobiles 51a,b(ERFa,b).

(72) The differential functions with flat gearing and comprises: a frame CH/52 rotating around the axis ZD two output mobiles Sa, Sb along the axis ZD, linked together by at least one pair of satellites STa,b: ST′a,b mounted head-to-toe, each satellite having two pinions ST1a, ST1b; ST2a, ST2b carried by the same axle. Two satellites STa,b; ST′a,b meshing together By two homologous pinions ST2a,b; ST′2a,b and By the other pinion ST1a, ST1b; ST′1a, ST′1b one and the other with an output mobile Sa, b

(73) The satellites 55a,b (STa,b) are used as inverting links for the two output mobiles 53a,b (Sa,b). The inverters operate in pairs to cancel the resulting pressure on the gearing. The four satellites 55 (STa, STb, ST′a, ST′b) have the same number of teeth. The rotation axes of the satellites 55 (STa,b) are parallel to the rotation axis ZD of the differential 5(D) frame 52 (CH). The axes of the satellite 55 (STa,b) pairs are set in diametral opposition relatively to the axis ZD.

(74) The satellites 55a,b (STa,b) mesh simultaneously with their output mobiles 53a,b (Sa,b). As a consequence of the equal number of teeth, the two output pinions 532a,b (Sa,b) rotate at the same speeds in opposite directions, when considered in the differential frame referential.

(75) Following the same reasoning, in a referential that is exterior to the differential, the rotation speed of the differential frame 52 (CH) is equal to the averaged speed between the two output pinions 532a,b (Sa,b) rotation speeds.

(76) This layered differential 5 (D), uses flat gearings 53a,b, 55a,b (Pa,b, STa,b, 5a,b) to replicate the behavior of a conical gearing differential. Although more complex by having more elements, this configuration allows the usage of flat gearing norms (NIHS 20-25 for example) instead of less efficient and more complicated to machine conical gearing. Moreover the pivoting is more efficient due to having a rotation between two pivots.

(77) The two output pinions 531 of the differential 5 are attached to the output wheels 532 (Sa,b), meshing with the transmission mobiles 51a,b (ERFa,b), themselves meshing with the compensation wheels.

(78) In this likening of the FIG. 1 schematics and the FIG. 2 isometric perspective of a realization mode, the double tourbillon TD is shown first by it's cage 1 (CC) with cage wheel 10 (RC), split in two half-cages 1a,b. In each half-cage 1a,b sits one oscillator 4a,b, it's lever 3a,b (OSa,b) as well as the escapement mobile 2a,b (MEa,b). The belt wheel gearing 101 of the cage wheel 10 acts as the entry point EC set in motion by the horological mechanism MH.

(79) In a traditional tourbillon configuration, the fixed wheel is used as a circle on which the escape pinion rolls, which then transforms the cage rotation into a satellite motion around the fixed wheel.

(80) In the configuration described according to the invention, the cage 1 (CC) itself was slowed down and the remainder of the necessary motion was brought by the compensation wheel 50 (RF), thus replacing the fixed wheel. As a consequence, the compensated wheel is always pressing against the escapement pinion 20 (ME), which allows the introduction of a differential 5 (D) to take into account the discrepancies in regulation between the two compensated wheels 50a,b (RFa,b).

(81) The differential 5 (D) is set in motion by the rest of the movement (not shown) through it's input pinion 54 (ED) and it's frame 52 (CH).

NOMENCLATURE OF THE MAIN ELEMENTS

(82) T Horological Tourbillon TD Double Tourbillon CC Tourbillon Cage ZC Axis of the Double Tourbillon RC Cage Wheel, defining the medial plane OSa,b Oscillator Mea,b Escapement Mobile EC Cage Input RFa,b Compensation Wheel D Differential ED Differential Input ZD Differential Axis CH Differential Frame Sa,b Differential Outputs Pa,b Differential Output Pinions STa,b; ST′a,b Satellites ST1a,b Long Satellite Pinion ST2a,b Short Satellite Pinion ERFa,b Transmission Mobile MH Rest of the Horological Mechanism Cage 1a, 1b Half Cage 10 Cage Wheel 101 Cage Wheel Belt Gearing 102 Cage Bridge 11 Escapement Plate 12 Lever Bridge 13 Escapement Bridge 14 Cage Pivot 15 Shared Stud Holder 16 Pillar 161 Plate Bridge Pillar 2 Escapement Mobile 20 Escapement Pinion 21 Escapement Wheel 3 Lever (Complete) 30 Lever 31 Entry Pallet 32 Exit Pallet 33 Fork 4 Oscillator 40 Balance Axle 41 Balance Wheel Rim 42 Collet 43 Double Plateau 44 Ellipsis 45 Spiral Hairspring 450 Archimedean Spiral 451 Terminal Curve 46 Stud 5 Differential 50 Compensation Wheel 51 Transmission Mobile 52 Differential Frame 521 Frame Base 522 Frame Plates 523 Satellites Pivoting Points 524 Screws 525 Side Grooves 526 Differential Pivots 53 Differential Exit Mobile 531 Exit Mobile Tubular Pinion 532 Exit Mobile Wheel 54 Differential Input Pinion 55 Satellite 551 Satellite Long Pinion 552 Satellite Short Pinion 553 Naked Axle 56 Differential Feeder Wheel

(83) In order to simplify the presentation of the claims, every similar references are not systematically retranscripted in the claims. They only are when it is necessary for the understanding.