CA1114629A - Universal homokinetic joint - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE :
Homokinetic joint of the type in which the torque is transmitted between two ends by balls engaged in races or tracks made in said ends.
Each track is constituted by two semi-cylindrical grooves, the sectional diameter of which being oriented relative to a radial axis passing through the geometrical center of the joint and perpendicular to the longitudinal axis of said two ends. The balls are thus made to roll and to be guided between two poles located on the radial axis and two other poles located on an axis perpendicular to said radial axis. Said arrangement excludes the use of any interme-diate means for maintening the balls on the bisecting plane of the joint.
The invention is particularly adapted to realize the two-joints transmission assembly for a vehicle.

Description

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BRIEF SUM~LARY OF TH~ INVENTION
The present invention relates to a homokinetic joint of the type in which the tor~ue i8 transmitted between two end~ by balls engaged in races or tracks made in said ends.
The in~ention relates to a homokinetic joint wherein each track is constituted by two semi-cylindrical grooves, the 3ectional diameter o~ each o~ said groo~es being dlagonally oriented relative to a radial axis pass-10 ing through the geometrical centre of the joint and per- -pendicular to the longitudinal axis of the two ends of the Joint, as a result each of the balls i~ made to roll and is guided between two pole~ located on said radial axis and two other pole~ located on an axi~ perpendicular to the radial axis, ~aid arrangement with ~our poles excluding the use o~ intermediate means for constantly and imperatively maintaining the balls on the bisecting plane Or the respecti~e longitudinal axes of the two enas ana causing the balls to transmit the torque in the two rotational direotions of the ~oint, unitary pressures on the bQlls being considerably reduced in one o~ these two rotatlon dlrectlon~.
Due to the new technlque used there are numer-ou8 constructional embodiments o~ the ~oint according to the invention. They can recel~e a ~ariable quantity o~
balls and their two ends may either mo~e longitudinally with respect to one another, their axial centering being - . , .

ensured by the balls, or conver~ely they can be longitud-inally centred relative to one another by conca~e sur-~aces acting in convex sur~aces provided on the ends.
In addition to the ~undamental ad~antage of obviating the u~e of intermediate means ~or imperati~ely maintaining the balls on the bisecting plane of t~e ioint -according to the invention also makes it possible to reduce the angle gi~en to the groo~es forming a housing ~or the ball, their addition not necessarily being greater than that o~ the maximum angular work of the ~oint due to the in~ersion o~ the angle occurring during sald angular work.
The angle of the groo~e~ mag even be zero in ~oints operating with a constant angular velocity, the latter then being substituted ~or the zero angle o~ the groo~es .
The transverse space separating two grooves permit their displacement in the angular work o~ the ~oint and i~ either parallel to the axis thereof passing through th0 geometrical centre or the ~oint or, as a variant, is positioned diagonallY relative to said axis.
In sliding ~oint~ the ball~ can be introduced with the ends ~acing. In longitudinally centred Joints a ~irst ball is introduced into its grooves up to the blsecting plane thereo~ and with the groo~es at a zero angle relative to one another each of the other ball3 iB
then introduc ed in the same way, , .: . . .. .

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-. - ., BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics, advantages and ~eatures o~ the present invention can be gathered from the follow-ing description of non-limitative embodiments and with re~erence to the attached drawings, wherein show:
Fig. 1 a ~ront view o~ a ~irst possible embodiment o~
a ~oint according to the in~ention having integrated sliding and two balls.
Fig. 2 a prorile view o~ the outer end of the same joint as in Fig. 1.
Fig. 3 a pro~ile view o~ the inner end o~ the same joint as in Fig. 1.
Fig. 4 a profile view o~ the same joint as in ~ig. t, the two ends being embedded moderately in one another.
Fig. 5 a prorile view o~ the same ~oint as in Fig. 1, the two ends having slid in one another and being located on the same longitudinal axis.
Fig. 6 a prorile view of the same joint as in Fig. 1, the two ends having slid into one another in the opposite direction from that Or Fig. 5, the re~pective longitudinal axi~ thereor being dis-posed angularly wlth respect to the other, Fig. 7 a plan view in section along the line B - B' Or the outer end Or the joint o~ Fig. 1.
Fig. 8 a plan view Or the inner end o~ the joint of Fig.
1.

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6.~

~ig. 9 a ~ront view of a second possible embodiment of a ~oint according to the invention with integrated sliding and having four balls.
Fig. 10 a ~ront view o~ the outer end o~ the joint Or Fig. 9.
Fig. 11 a pro~ile view of the outer end of the joint of Fig. 9.
Fig. 12 a ~ront view o~ the inner end o~ the joint Or Fig. 9.
0 Fig. 13 a profile view of the inner end of the joint o~
Fig. 9.
Fig. 14 a pro~ile view o~ the joint o~ Fig. 9, but pro-vided with a protective casing with a ~loating shaft compensation spring, the two ends being embedded moderately in one another.
Fig. 15 the same pro~ile view as that of Fig. 14, the two ends having slid into one another.
~ig. 16 the same profile view as in Fig8. 14 and 15, whereby however the inner end has slid in the opposite direction to Fig. 15 and the respective longitudinal axis of the two ends being disposed angularly relative to one another.
Fig. 17 a ~ront view of a third possible embodiment of a ~oint according to the invention with inte-grated sliding and having six balls, the latter not being shown ~or reasons o~ the clarity Or the drawing.
Fig. 18 a prorile view Or the same joint as in Fig. 17, " " , ; .; ,~
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the two end~ being moderatel~ embeaded in one another.
Fig, 19 the same pro~ile view as in Fig. 18, the two end3 having slid into one another.
Fig. 20 the same pro~ile view a~ in Figs. 18 and t9, whereby however the inner end has slid in the opposite direction to that of Fig. 19, the long-itudinal axis o~ the two ends being disposed angularly relative to the other and the inner end is provided with its sha~t.
Fig. 21 a pro~ile view of the joint of Fig. 17, but ~ro-vided with a ~rotective casing with floating sha~t compensation spring, the two ends being moderately embedded in one another.
5 ~lg. 22 a ~ront view o~ a ~ourth po6sible embodiment o~
a ~oint according to the in~ention with integrated sliding and having four balls.
Fig. 23 a pro~ile view with part section o~ the outer end o~ the ~oint o~ Fig. 22.
Fig. 24 a profile view o~ the inner end o~ the ~oint o~
Fig. 22 provided with its sha~t, Fig. 25 a diagrammatic profile view of the two ~oints o~
~lg. 22 coupled for use ~or example ln a veh1cle transmission with rear propulsion and independent wheels, said transmission being in plan ~iew rel-atlve to the de~lection o~ the vehicle wheel, the two ~oints being o~-centred relative to one .

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1 another in such a way as to-obtain a constant shear of the four balls in their receiving groo~es. ;~-Fig. 26 diagrammatically and with a small partial section the same transmission as in Fig. 25, but in profile with, (after a 90 rotation) relative to the latter and provided with a protective casing with floating shaft compensation spring between the two joints. ~ -Fig. 27 the same transmission as in Fig. 26, but in a position of displacement between the two joints.
Fig. 28 a front view of a fifth possible embodiment of a joint according to the invention wi~h integrated sliding and having four balls.
Fig. 29 a profile view with part section of the outer end of the joint of Fig. 28.
Fig. 30 a profile view of the inner end of the joint of Fig. 28.
Fig. 31 a profile view of the joint of Fig. 28, the two ends being moderately embedded in one another.

Fig. 32 a profile view of the joint of Fig. 28, the two ends having slid longitudinally into one another.

Fig. 33 a pxofile view of the joint of Fig. 28, the two ends having slid longitudinally in the opposite direction to that of Fig. 32 and the respective longitudinal axes being disposed angularly with respect to one another.
THE DETAILE~ DESCRIPTION OF THE PREFERRED EMBODIMENTS

According to a first possible embodiment of a joint with two balls and with integrated sliding in accord-ij~ .

~ ance with the present in~ention, shown in exempli~ied man-ner in Fig~. 1 to 8, said joint e~sentially com~rises an inner end 1 in which are made tno groo~es ~a and an outer end 2 in which are made two complimentary grooves 2a.
According to an essential ~eature o~ the invention the ~our grooves are semi-cylindrical and race one another in pairs to receive the t~o balls 35 and 3i and their diameter, in cro~s-section, i~ oriented in the manner clearly 3hown in Fig. 1 in accordance with a diagonal D, it being im~ort-ant to note that this diagonal mu~t be reversed in thecase of a reversal of the rotation direction ~ o~ the ~oint.
- Moreover, grooves 1a and 2a are made in ends 1 and 2 in such a way that the centres Cs and Ci o~ the two balls 38 and 3i~ when the ~oint occupies the poRition o~
balance shown in Figs. 1 and 4, are positioned symmetrically relative to the geometrical centre 0 o~ the ~oint. Each o~ the centres of the two ball~ i~ positioned, in accord-ance with the ln~ention, at the intersection o~ on the one hand the radial axis M ' passing through the geometrical centre 0 of the ~oint and perpendicular to the longitudinal axis XX o~ the two ends of the ~oint and on the other hand Or a transverse axis of symmetry C-C' perpendicular to the axis AA' and ~inally o~ the diagonal D, whic~is in ~act the bisectrix o~ the right angle bet~een the axes CC~ and AAI. It should be noted that the trans~erRe axis C-C' 18 also parallel to the axis BB', which passeg through the geometrical centre 0 o~ the ~oint and is also perpendicular to the longi~inal axis XX o~ the two ends of the ~oint and ~, - . . ; -., , . . ..
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o~ axi 8 AA ~ .
It can be gathered from the drawings and in part-icular Fig. t that this diagonal arrangement o~ the grooves 1a and 2a causes each o~ the two ball~Q 38 and 3i to roll 5 and be guided between two poles located on the radial axis AA' perpendicular to the longitudinal axis XX o~ the ~oint and two other pole~ located on the axiQ CC' perpendicular to the radial axis.
Thu~, the torque i8 transmitted in directions to 10 the right or le~t, but it ~hould be noted that the rotation in direction E of the ~oint i8 pre~erred i~ end 1 i8 leading and end 2 i8 led.
According to another feature of the invention grooves ~a and 2a are oppo3itely and symmetrically inclined ~5 with respect to the longitudinal axis XOX of endQ ~ and 2.
Thu~, the opposlte inclination angle F Or grooves 2a of end

2 relati~e to longitudlnal axis XOX of the joint corres-ponds to inclination angle G o~ groo~es 1a o~ end 1 rel-ative to the same longitudinal axis XOX, as can best be 20 seen ~rom Fig. 4. ~oreover, and as is apparent ~rom Figs.
t, 2 and 3, the longitudlnal axes o~ grooves 1a and 2a are perpendicul~r to the transverse axis CC'.
For exam,ple four holes 2b are advantageously made in end 2 in such a way as to permit the rixing thereo~ to a r 25 support, whllst it being obvious that any other fixin~ pro-cess can be used.
In this case the introduction of the two balls 38 and 3i into their re~pective complimentary grooves t a and _~ .

, . ; ~. .. . , ., . . .. - .- -~ ' .!, ' .. ' ` ' ', ' ,' , ' , . . ';. ', ., . ;'. . ' ' " '-. -. i`'' ' ' '. '.' . . ' '.' .`'' . ' "
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- ~b i~ very simp}e, because the joint is sliding, It is merely necessary to bring the two ends into a ~acing pos-ition, place the two balls at the inlet for grooves 1a for exam~le and then push end ~ within end 2 until the centres of the balls and the bisecting plane HH are in the median position o~ Fig. 4.
When the two balls 3s and 3i have been introduced in this way and the two ends 1 and 2 are brought into the media~ embedding po~ition o~ ~ig. 4 it can be seen that the centres C8 and Ci of the balls 38 and 3i are positioned on the bisecting plane HH, which i8 then perpendicular to the longitudinal axis XX of the joint and contains the geomet-ricalce~reO o~ the latter, As a re~ult o~ the invention the balls are thus constantly and imperatively po~itioned on the bisecting plane HH without the use o~ any intermediate means.
It is readily apparent that if inner end ~ i8 slid in outer end 2, whilst maintaining said end~ in such a way that they remain on the same longitudinal axis XOX
in order to pass ~rom the relative position o~ Fig. 4 to the relative position o~ Fig. 5 bisecting plane HH i8 translated parallel to itsel~ by a distance equal to hal~
the di~erence b~ which end 1 has moved relati~e to end 2.
During thls displacement balls 38 and 3i have rolled in the two corresponding groove~ ~a and 2a, their centre C8 or Ci having been displaced by half the distance by which the complimentary grooves la and 2a have been displaced relative to one another, whil~t remaining imperatively ) . . . . . .. . ..

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po~itioned on the bisecting plane HH during the displace-ment thereo~.
If now end 1 is turned within end 2 in order to pa88 from the relative position of Fig. 4 to the relative position of Fig. 6 it is immediately apparent that in this case the lower ball 3i remains stationarY, whilst the upper ball 38 rolls between the complimentary upper grooves, its centre Cs being diæplaced by hal~ the distance by which groove 1a moves relative to groo~e 2a. In this case the bi3eating plane HH i8 mo~ed by piYotin~ about centre Ci o~
lower ball 3i which remains stationary, centre Cs of upper ball 38 and the geometrical centre O of the joint remaining constantly positioned on the bisecting plane ~ durin~ the pivoting thereo~.
Obviously i~ end 1 rotates whilst moving end 2 balls 38 and 3i roll and are guided between two poles located on ~Xi8 AA~ and two poles located on axis CC', the centres C8 and Ci o~ the balls being thus imperatively main-tained on the bisecting plane HH, ~ithout intermedlate means being necessary.
It is also clear that the two balls 38 and 3i transmlt the torque in the t~o rotation directions o~ the Joint, whereby it should be noted that the unitary pres-sures on tho balls are considerably reduced in one o~ the two rotation directions.
According to a second possible embodiment of a ~oint according to the invention having ~our balls and with integrated sliding, ~hown in exemplified manner in --t3--.

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5~3 ~igs. 9 to 16, the ~oint essentially com~rise~ an inner end 21 having ~our grooves 21a and an outer end 22 having four complimentary grooves 22a. The four groups of two compli-mentary groo~es are uniformly distributed relative to the geometrical centre 0 of the joint facing one another in pairs in order to receive the ~our balls 23a, 23b, 23c and 23d. According to the essential ~eature o~ the invention all the grooves are semi-cylindrical and oriented on this occasion in accordance with two inverse diagonals D-D'.
tO As in the previously described cases this arrange-ment causes each o~ the balls 23a, 23b9 23c and 2~d, such as ~or example ball 23c, roll and be guided in grooves 21a and 22a between two poles located on a radial axis AA' and two poles located on an axis CC' perpendicular to the first, centre Cc o~ the ball bei~g located at the i~ersection o~
said axes AA' and CC' and the corresponding diagonal D', which is the bisectrix o~ angle C,Cc,A'~
In this case the torque is transmitted either to the right in the direction E' or to the le~t in direction E.
Moreover, grooves 21a and 22a are oppositely and symmetrically inclined relative to the longitudinal axis XX
of ends 21 and 22. The opposite inclination angle F of grooves 22a of end 22 corresponds to the inclination angle G o~ grooves 21a of end 21, the loneitudinal axes o~ the grooves being perpendicular to the axi~ CC' whereby, as ~tated hereinbefore, the latter i9 perpendicular to the radial axi~ AA' and parallel to the axis BB' pas~ing through the geometrical centre 0 of the joint.

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~ Through the combination of all these conditions balls 23a, 23b, 23c and 23d are constantly and imperatively positionea in the same sliding bisecting plane HH (c~
Figs. 14, 15, 16).
According to the represented embodiment the structure o~ the outer end 22 has clearances 22b, 22c and 22e and a projection 24 made ~rom a flexible material and which is inserted in a blind hole 22d and ha~ theeffect of limiting,the travel of end 21, which is e~uipped with a floating sha~t 25 having male channels 25a engaged in the bore,with female channels 21b.
The balls are introduced into their respective ¢omplimentary grooves in the manner described hereinbe*ore with re~erence to the joint with integrated sliding represented in Figs. ~ to 8.
Dif~erent phases of the angular work and the sllding of the Joint are illustrated in Figs. 14, 15 and 16 and a detailed description thereof will not be provided again.
It should be noted that the ~oint sho~n in these drawings i8 advantageously provided with a protective de~ice comprising a cap 26 welded at 33 onto outer end 22;
a second cap 27 welded at 34 onto cap 26 and provided with a recess ~or a gasket 29 made from a ~lexible material appropriate for the friction and therefore having a high Shore hardness and a third cap 28 extended by a tubular portion 28a ha~lng a recess for a gasket 28b, said cap 28 acting between end 22 with which it iQ not in contact and ~3 .. .

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.,, . ' ' : ' ` ., ,' . - ,,.:

~ 4~

~ cap 27 against which it bears in order to compress a spring 35 against end 21. The function of spring 35 is to rel- -atively balance the floating shaft 25 between the joint of Figs. 14, 15 and 1 6 coupled in tandem to another sliding joint (not shown in the drawing~), which is provided with an identical spring which, like spring 35, always works in compression. Finally a gasket 30 made from a flexible material is embedded between t~o slotted washers 31 and 32, whereby said device can advantageously be com~leted by a grease ~itting.
According to a third possible embodiment of a ~oint according to the inven~on having six balls and with *
integrated sliding, shown in exemplified manner in Figs.
17 to 21, the ~oint essentially comprises an inner end 41 r having 8iX grooves 41a and an outer end 42 having six com-~limentary grooves 42a. The ~ix groups of two compli-mentary grooYes are uniformly distributed relative to the geometrical centre 0 o~ the ~oint, whereby they face one another in pairs ~or receiving the six balls such as 43a, 43b, 43c, 43d, shoYm in Fig~. 19 and 20. In accordance with the e~sential characteristic of the invention all ; these grooves are semi-cylinarical and oriented in accord-ance with a diagonal D, whereby it should be noted that the latter must be reversea in the case of the reversal of the rotation direction E of the ~oint.
As in the previou~ cases described hereinbefore thi~ arrangement cau~es each of the BiX balls, ~uch as ~or example ball 43a to roll and to be guided in groove~
~S' .
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- : ; , . - . .. . . . .

--. - ~ . -. . . - .. - ~
.: . . . -. . - ;

41a and 42a between t-qo poles located on a radial axis AA' and two poles located on an axis CC' perpendicular to the ~irst axis. The toraue is therefore transmitted in two directions, to the right or to the left, the rotation in direction E being preferred if the inner end 41 is leading and the outer end 42 led Moreover the grooves 41a and 42a are oppositely and symmetrically inclined relative to the longitudinal axis XX o~ ends 41 and 42. The opposite inclination anglé F o~ grooves 42a o~ end 42 corresponds to inclination angle ~ o~ grooves 41a o~ end 41, the longitudinal axes of said groove~ being per~endicular to axis CC' which, as has been stated hereinbefore, is perpendicular to the radial axis AAt and parallel to the axis BB' passing through the geometrical centre O of the joint, As can be gathered ~rom Figs..19 and 20 when all these ~onditions are combined tne six balls must be con-stantly and imperatively positioned in the same sliding bisecting plane HH, the balls ef~ecting half the sliding of end 4~ in end 42.
Obviously the two ends 41 and 42 are separated by a su~icient space to permit their angular work, as shown in Fig. 20.
For example six holes 42b are advantageously made ln end 42 in order to permit the ~ixing o~ the latter to a support, whereby it is obvious that any other ~ixing process may be used. ~oreover, the driving sha~t 45 ~or end 41 is ad~antageously provided with male channels 45a . - . - , . ,- , .,,.,. . - . . . -' ' . ., : . . ' ' . ' ' . ' !

... . . . . . ... . . ..

~orce-~itted into corresponding ~emale channels 41b in end 41.
The introduction o~ the six balls into their respective complimentary groo~es is carried out in the man-ner described hereinbe~ore with reference to the sliding joint of Figs. 1 to 8.
Fig. 21 show3 the ~oint in the form which it assumes when equipped with a protective de~ice. In the represented em~odiment the latter com~rises a cap 44 welded *
at 51 to outer end 42 after the insertion of a cap 46 and a spring 47. ~hi~ spring is compre~qed between cap 46 and end 41 and serves to relatively balance the floating shaft 45 bet~een the Joint o~ Fig. 21 and another identical slid-ing Joint and equipped with an identical spring constantly working in compression, said other Joint (not sho~n) being cou~led to the ~oint o~ Fig. 21. Tne protective device also advantageously has a bello~Ns 48 made ~rom a ~lexible material and which is fixed on the one hand to cap 44 by means o~ a metal rein~orcing ring 49 inserted lnto an appropriate groove of said cap and on the other hand to sha~t 45 by means o~ a clamp 50.
According to a fourth possible embodiment o~ a Joint accordlng to the invention with ~our balls and inte-grated sllding, shown in exempli~ied manner in Figs. 22 to 27, the Joint essentially comprise~ an inner end 61 having ~our grooves 61a and an outer end 62 having four complimen-tary grooves 62a. The four group~ o~ two complimentary grooves are uniformly distributed relative to the geomet-_ffl_ "` ir2~

-' `' ' ~' ': ~ . . . -., ` - ~
- ' :' '- :; ~ ' " ' -.

rical centre 0 o~ the ~oint, Whereby they face one another in pairs to receive the ~our balls 63a, 63b, 63c and 63d.
According to the essential ~eature o~ the invention all the grooves are semi-cylindrical and oriented in accordance with a diagonal D, whereby it should be noted that the latter must be rever3ed in the case o~ a reversal of the rotation direction E of the ioint.
As in the previously described cases thi~ arrange-ment makes each o~ the ~our balls, such as ~or example ball 63a roll ~etween two poles located an a radial axis AA' and two poles located on an axis CC' per~endicular to the ~irst axis. Thus, torque is transmitted in two directions, to the right or to the left, the rotation in the direction being pre~erred i~ the inner end 61 is leading and the outer end 62 led.
According to a special feature of the present embodiment the respective longitudinal axes G and F of groove 61a o~ the inner end and groove 62a of the outer end ¢oincide and are parallel to the longitu~inal axis XX of said ends 61 and 62.
This arrangement, which makes machining easier, makes it necessary ~or the purpose of obtaining the con-stant angularity o~ the two complimentary groo~es and con-stantly and imperatively positioned balls 63a, 63b, 63c and 63d on the ~ame bisecting plane HH to angularly position the said complimentary grooves 61a and 62a relative to one another by dis~lacing the two identical ~oints J1 and J2 constltuting a complete transmission relative to one --tg- A

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another during assembly.
Fig. 25 ~hows a plan view o~ ~uch a transmission assembly. The ~alls are introduced into their respective compllmentary grooves 61a and 62a in the manner de~cribed herelnbe~ore with re~erence to the integrated sliding ~oint shown in Figs. 1 to 8. ;~
The assembly procedure becomes very clear by comparing Fig. 26, which i8 a plan view of a complete transml~lon system with two ~oints J1 and J2 and in which the angle ls zero and Flg. 27 which i8 a profile view of the same ¢omplete transmission system with two ~oints J1 and J2 and in whlch the constant angularity bet~een the t~o axes ~ and ~ is obtPined by the dis~lacement o~ the two ~oints J1 and J2.
These Joints msy advantageously be provided with a protective device comprlsing a belloWs 68 made from a M exlble material and ~ixed to end 62 and to shart 64 by olam~s 69 and 70. A conlcal spring 65 working in exten-sion i8 lnserted in a groove 62b o~ end 62 and i9 locked by a washer 67 welded to shsft 64 and a washer 66 locked by the sleeve o~ bellows 68. The ~unction of ~pring 65, constantly worklng under extension, i9 to relatively bal-ance the ~loating sha~t 64 between the two ends 62 of Joints J1 ~nd J2~ said sprlng preventlng the ball~ f~om bei~g removed ~rom thelr race. Obvlously thls solution i8 not obligatory and can be replaced by sny equivalent solutions permitting the same result to be achleved.
Accordlng to a ~l~th posslble embodiment o~ a , ; ~.
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~oint according to the invention with ~our ball~ and inte-grated sliding, which is shown in exempli~ied manner in

3~ig8. 28 to 33, ~aid joint comprises an inner end 71 with ~our grooves 71a and an outer end 72 with ~our ~omplimen-5 tary grooves 72a. The four groups o~ two complimentarygrooves are uni~ormly distributed relative to the geomet-rical ¢entre 0 o~ the ~oint, facing one another in pairs 80 às to recet~re the ~our balls 73a, 73b, 73c and 73d.
According to the essential ~eature Or the 10 invention all the groo~res are semi-cylindrical and oriented in accordance with a diagonal D, whereby it should be noted that the latter must be reversed i~ the rotation direction E of the ~o~nt is rever~ed.
As in the previously described cases this 15 arrangement makes each o~ the four balls, such a~ ~or example ball73a roll and be guided between two poles lo¢ated on a radial axi8 AAI and two poles located on an a~ci8 CCI perpendicular to the ~irst axis. The torque i~
transmlttea in two directions, to the right or to the left, 20 the rotatlon in direction E being preferred if the imler ~ end 71 is leading and the outer end 72 led.
Accordlng to a reature of the present embodiment the longltudinal axes of the grooves o~ one end are ang-ularly rever6ed relative to the grooves o~ the other end, 25 but the sy~tem of grooveB i8 oriented in the ssme direction.
Thu~, two of the grooves 71a and 72a csn have their inclination angle G-F centred on sxisAA', whilst the inclination sngles o~ the two other grooves 71a snd 72a ~S' .. . . . : : :...... . : .

1 can be parallel to axis BB', whereby said arrangement can facilitate machining, the angles G-F of each of the grooves intersecting on axis CC'. -;
The four balls are introduced into their respective complimentary grooves in the manner described hereinbefore relative to the integrated sliding joint shown in Figs. 1 to 8.
Moreover, shaft 74 may form an integral part of one of the ends, for example inner end 71 or conversely can be connected to said end.

The inclination angles G-F of the grooves, according to Fig. 31, intersect on the bisecting plane HH, but the said grooves may also be longitudinally displaced to the right or left during machining, whereby the bisecting plane HH follows said displacement.
Whereas in Fig. 31 ends 71 and 72, as well as bisecting plane HH of the joint are centred on the geometrical centre 0 of the joint, in Fig. 32 ends 71 and 72 have slid longitudinàlly and in Fig. 33 this sliding is effected in the opposite direction and, in addition, the ends are angularly inclined relative to one another. It is clear that in all these respective movements the bisecting plane has effected half the respective sliding of the ends and that the four balls have remained constantly and imperatively positioned on the bisecting plane during these movements.
Obviously the present invention has only been described and represented in a preferred exemplified manner and numerous equivalent modifications can be made thereto without passing beyond the scope o~ the invention as de~ined in the rollowing claims.
~hus, various modi~ications can be made with a view to reinrorcing the components.
It is also obvious that lr the axial centering o~ the sharts is automatically ensured by the balls the Joints can be longitudinally centred by means o~ hemispher-ical caps in accordance with a grior art method.
Moreover when the ~oint has a protective device in which a spring is used the latter can either ~orX in compression or in extension, or can be neutral at mid-travel and then work either in compression or in extension, the function o~ one or other Or these springs is to main-tain a relative balance o~ the rloating shaft connecting ~5 the two Joints ~orming a transmission system.
It is ob~ious that the two ~oints rorming a trans-mission system may or may not be identical, i.e. one o~ the ~olnts can slide and the other not slide or the two Joints can ~lide.

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Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A homokinetic joint for the transmission of a torque between two ends, races being made in said ends, by balls engaged in said races, comprising an inner end and an outer end, at least two tracts whereof each is constituted by two semicylindrical grooves made respectively in the inner end and the outer end, each of said grooves having its diameter in cross-section contained in the bisecting plane passing through the geometrical centre of the joint and the geometrical centre of the ball contained in the groove, oriented diagonally in accordance with the bisectrix of the angle between a radial axis, passing through the geometrical centre of said ball and said geometrical centre of the joint and perpendicular to the longitudinal axis of the corresponding end, and an axis per-pendicular to said radial axis and passing through the geometrical centre of the ball in question, as a result of which each of the balls is made to roll and to be guided between two poles located on the radial axis and two other poles located on the axis perpendicular to the radial axis which has the effect of constantly and imperatively maintaining the geometrical centres of the balls on the bisecting plane of the respective longitudinal axis of the two ends and of causing the balls to transmit the torque in two rotation directions of the joint, the unitary pressures on the balls being considerably decreased in one of the two rotation directions.

2. A homokinetic joint according to Claim 1, wherein the inner end has the possibility of sliding longitudinally within the outer end, the bisecting sliding plane and the balls effecting half the sliding action, a sufficient space separating the two ends to permit their angular work and the two grooves forming a ball race being disposed ang-ularly with respect to the longitudinal axis of the two ends, the longitudinal axes of the two grooves of one race being symmetrically inclined in accordance with inverse angles and intersecting on the sliding bisecting plane of the joint.

3. A homokinetic joint according to Claim 2, wherein half the ball race is oriented diagonally in one direction and the other half of said race is oriented in the opposite direction, the torque being transmitted between the two ends under the same conditions in both rotation directions of the joint.

4. A homokinetic joint according to Claim 2, wherein the two grooves forming a ball race are positioned parallel to the longitudinal axis of the end in which they are made, the constant angularity of the two grooves being obtained by a displacement at the time of assembly of the two joints, whose inner ends are connected by a common float-ing shaft, the two thus assembled joints forming a complete transmission system.

5. A homokinetic Joint according to Claim 2, wherein the longitudinal axes of the grooves of one of the ends are angularly reversed compared with the longitudinal axes of the complimentary grooves of the other end, but the system of grooves of the same end is oriented in the same direction.