Articulated transmission joint having a large telescopic travel in particular for an automobile

In an articulated transmission joint for automobiles, there is provided a large telescopic range of travel for the joint. A first shaft having a tripod element composed of three radial arms is joined to another shaft with a bowl element. The bowl element is provided with rolling tracks therein. Each arm of the tripod element has two roller segments pivotable thereabout. The roller segments are in rolling contact with the rolling tracks of the bowl element. Each set of roller segments not only has an arrangement for limiting the angular range of movement of the roller segments about their respective arms, but also is provided with an arrangement for limiting the range of telescopic movement of the arms to a maximum extension and a maximum compression position. This arrangement further ensures that the roller segments are at their respective limits of angular movement about each arm when their arm is at an end point of its range of movement in the bowl element. The above-mentioned arrangement is provided by abutments on the roller segments for cooperation in engagement with abutments of the bowl element. The abutments of the bowl element may be formed in the bowl element itself, or may be formed on a clip provided in the bowl element. The joint ensures, in a reliable manner, a large telescopic range of travel.

BACKGROUND OF THE INVENTION 
(1) Field of the Invention 
The present invention relates to an articulated transmission joint, having 
a large telescopic travel, in particular for an automobile. 
The invention is in particular applicable to homokinetic transmission 
joints comprising a first element, or tripod element, provided with three 
arms disposed substantially radially relative to its axis and each partly 
surrounded by two roller segments whose radially outer surfaces, having a 
curved transverse contour, are in rolling and sliding contact with 
longitudinal tracks of a second element. Usually, the longitudinal tracks 
are formed on the inner side of a hollow element of generally cylindrical 
shape termed a "bowl element" or "barrel element" surrounding the tripod 
element. 
(2) State of the Prior Art 
Such a joint is disclosed in the unpublished French patent application No. 
86 17044 in the name of the Applicant. This joint has excellent features 
of comfort and compactness. It is simple and cheap and therefore very 
competitive. 
In service, the movements of each arm of the tripod element, as resulting 
from the telescopic movement of the joint, or from the operation at a 
flexing angle of the joint, result in principle in a non-sliding rolling 
of the roller segments on their respective rolling track. This rolling 
movement is such that, when an arm of the tripod element travels toward 
either of the ends of its axial travel in the barrel element, the 
associated roller segments move away toward the rear of the arm relative 
to the considered direction of axial movement. This in principle permits 
giving to the joint a reduced axial overall size for a given movement 
capacity. 
However, this capacity of movement, defined by the extent of the 
angularity-sliding diagram, depends on the reliability with which the 
roller segments take up their well-defined position corresponding to their 
minimum axial overall size when the joint is at the end of its compression 
or extension travel. 
In order to ensure this reliability, the aforementioned patent application 
proposes meshing the roller segments with racks provided in the barrel 
element along the rolling tracks. However, the racks only allow the 
telescopic movement by the rolling of the roller segments, which limits 
the telescopic travel substantially to the circumferential length of the 
toric outer wall of the roller segments. This is counter to the intended 
objective, which is to provide the longest possible sliding length for a 
given angularity and diameter of the joint. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a device which increases 
the movement of the joint without adversely affecting its overall size and 
its manufacturing or assembling cost. 
The invention provides a telescopic articulated transmission joint, in 
particular for a vehicle, comprising a first element provided with three 
arms disposed substantially radially relative to its axis and each partly 
surrounded by two roller segments whose radially outer surfaces, having a 
curved transverse contour, bear against longitudinal tracks of a second 
element relative to which each arm of the first element is movable in a 
predetermined telescopic travel, wherein the roller segments, on the one 
hand, and the second element, on the other hand, carry abutment means 
which, when the arms are substantially at the end of their telescopic 
travel, retain by an at least indirect mutual bearing relation the roller 
segments in a clearance position in which they clear a region in front of 
the arms relative to the movement toward said end of the telescopic 
travel. Angular travel limiting means are provided for limiting the 
angular travel of the roller segments about the associated arms, and, when 
the arms are in an intermediate region of their telescopic travel, the 
abutment means permit a free angular positioning of the roller segments 
around the arms within the limits defined by the angular travel limiting 
means. 
The abutment means according to the invention are effective to ensure that 
the roller segments move away in front of the arms when the latter arrive 
at the end of the telescopic travel. 
On the other hand, in contrast to the segments having a rack disclosed in 
the French patent application No.86 17044, the roller segments according 
to the invention freely position themselves about the arms when the arms 
are in the intermediate region of their telescopic travel. Thus, this 
intermediate region may be as long as is desired so that the total 
telescopic travel is larger than the circumferential length of the outer 
wall of the roller segments. When a roller segment reaches the extreme 
angular position about the associated arm, the remainder of the telescopic 
travel results in a sliding of the roller segment on the associated 
rolling track. When an arm travels toward the end of its travel, the 
mutual bearing relation of the abutment means occurs the as soon as the 
associated roller segment is in an unfavorable angular position for 
arriving at the end of the travel. This mutual bearing relation constrains 
the roller segment to assume its clearance position while the arm 
continues its movement. 
The abutment means provided in accordance with the invention may be 
operative at either of the ends of the telescopic travel of each arm, or 
at both ends thereof. 
If the abutment means are in mutual bearing relation when the arms are at 
an end of the telescopic travel corresponding to the maximum extension of 
the joint, it is advantageous to arrange that the angular travel limiting 
means define for the roller segments in the vicinity of their angular 
clearance position, a limit angular position in which the inner surfaces 
of the two roller segments associated with each arm have regions which 
converge in the direction away from the second element so as to retain the 
arms therebetween and thereby define to end of the telescopic travel. 
In this way there is achieved a locking of the assembled joint without any 
additional member, this locking precluding any undesired coming apart 
during the handling when storing or mounting on the production line. This 
dispenses with the anti-disassembly caps of conventional type which are 
costly, space-consuming, and are liable to result in leakages of 
lubricant, and which in any case, constitute a hindrance in the event of 
repairs. 
The abutment means of the roller segments may be bosses carried laterally 
by the segments. Each roller segment may carry one or more of such bosses, 
but preferably there is a single boss having two abutment regions, each 
region adapted to be in at least indirect bearing relation to the abutment 
means of the second element at a respective one of the ends of the 
telescopic travel. 
In practice, this boss may come into sliding or non-sliding bearing 
relation to complementary abutment surfaces provided in the barrel element 
or an intermediate steel member which cooperates in turn with the abutment 
means of the second element or barrel element so as to place the roller 
segment in the position clearing the path of the associated arm toward the 
end of its travel.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In the example shown in FIG. 1, the homokinetic transmission joint 
comprises a first element, or tripod element, comprising a ring 1 having 
an axis X--X from which radially outwardly extend three radial arms 2 
angularly evenly spaced about the axis X--X. The lateral wall of each arm 
2 is formed by a convex spherical region 3 who center is located at a 
distance from the axis X--X. This tripod element is fitted and fixed on 
the driving shaft 4 which also has the axis X--X. 
Each arm 2 of the tripod element is partly surrounded by two rolling 
elements, or roller segments, 6 whose radially inner concave spherical 
surface (relative to the axis of the arm) is in swivelling contact with 
the spherical region 3 of the arm. The radii of curvature of the spherical 
regions of the arm and the spherical surfaces of the roller segments are 
equal. 
The roller segments 6 also comprise a radially outer toric surface ( 
relative to the axis of the arm) by which they are each in rolling contact 
with a respective one of six rolling tracks 9 provided inside a second 
element, or bowl element, 10 fixed to a second shaft 10a of the joint as 
shown in dot-dash lines in FIG. 2a. 
The rolling tracks 9 extend in a direction parallel to the axis Y--Y of the 
bowl element 10 and the second shaft 10a of the joint, which axis is 
coincident with the axis X--X when the joint is in a position in which its 
two parts are coaxial. The toric surfaces 8 of the segments 6 have a 
circular cross-sectional shape, and the rolling tracks 9 have a circular 
cross-sectional shape of the same radius. The axis of the toric surface of 
each roller segment passes through the center T of its spherical surface, 
which coincides with the center T of the spherical region of the 
associated arm of the tripod element. 
When the joint operates in contraction-extension (termed hereinafter 
telescopic movement), each arm 2 moves in a direction parallel to the axis 
X--X in the bowl element 10. When the joint operates at a flexed angle, 
i.e. when there is an angle A between the axis X--X of the tripod element 
1 and the axis Y--Y of the barrel element 10 (FIG. 3), the plane of the 
tripod element ,is the plane of the axes of the arms 2, is inclined 
relative to the axis Y--Y so that, upon each rotation of the shafts 4 and 
10a, each arm 2 undergoes in the bowl element 10 a reciprocating movement 
in a direction parallel to axis Y--Y. The amplitude of this movement, 
which depends on the angle A between the axes X--X and Y--Y, is shown in 
FIG. 3 in which there have been shown respectively in full line and 
dot-dash line the same arm 2a at the two points of its travel 
corresponding to the two ends of the telescopic component of this travel 
at the angle A. 
The expression telescopic movement is employed for the movement or the 
movement component of an arm 2 in a (direction parallel to the axis Y--Y. 
The expression telescopic travel is employed for the extent of the 
telescopic movement. 
It is desired that, in telescopic movements of normal extent, the roller 
segments roll without sliding in their associated rolling track 9 and 
slide by their inner spherical surface against the spherical surface 3 of 
the arm 2. However, the telescopic travel allowed by the simple rolling of 
the roller segments 6 in their respective track 9 is relatively limited. 
It is indeed at the maximum equal to the circumferential length of the 
toric surface 8. FIG. 2 shows one half of this travel: in the situation 
shown in full line (position T1 of the center T), the roller segments are 
in a mean angular position about the axis Z--Z of the arm 2. In the 
position 6a shown in dot-dash lines, the roller segment 6 occupies one of 
its limit angular positions about the arm 2, which is shown only by the 
position T5 of the center T of its spherical region 3. Another semi-travel 
of the same length is possible beyond the position To up to a position of 
the arm 2 shown by the position T4 of the center of its spherical region. 
In this position, the segment 6 is at its other limit angular position 
about the axis Z--Z. 
Means are provided to ensure that the angular travel of the segments 6 
about the axis Z--Z does not exceed the aforementioned limit positions. In 
the illustrated embodiment, as an example of these means, the radially 
outer surfaces of the roller segments 6 comprise at each end of the 
section of a torus 8 a cylindrical sliding region 15 connected in a 
continuous manner to the section of a torus 8 and having a contour of the 
same radius corresponding to the radius of the contour of the tracks 9. 
Moreover, as clearly shown in FIG. 6, at each end of each segment 6, the 
cylindrical region 15 and the inner spherical surface are divergent, as 
shown by the directions L1 and L2 in FIG. 6, i.e. circumferentially 
outwardly of the segment, so that the arm 2 cannot be disengaged by a 
telescopic movement from a segment 6 in a limit angular position about the 
axis Z--Z. 
In the joint according to the invention, it is arranged that, beyond either 
of the positions T4 and T5 of FIG. 2, each arm 2 is capable of effecting 
an additional travel until its center T reaches the position of maximum 
compression T2 or the position of maximum extension T3. This additional 
travel is achieved by the sliding of the cylindrical sliding regions 15 in 
the rolling tracks 9. This sliding occurs easily owing to the film of 
lubricant interposed between the two cylindrical surfaces 15 and 9. In the 
position of maximum compression T2, the limited angular position occupied 
by the segment 6 about the axis Z--Z constitutes a clearance position 
relative to a surface 101a of the arm 2, which is the front side relative 
the direction of movement toward this end of the telescopic travel (see 
position 6b in FIG. 3). The surface 101a is planar and parallel to the 
axis Z--Z in the same way as an opposite surface 101b of the arm 2 so as 
to limit the axial overall size of the joint for a given maximum 
telescopic travel. Owing to this clearance position of the roller segment 
6, the surface 101a may very closely approach the inner surface 20 of the 
inner end of the barrel element 10. 
Likewise, when the arm 2 travels from its position T5 to its limit position 
T3, the limit angular position occupied by the roller segment 6 
corresponds to a clearance position relative to the front surface 101b of 
the arm 2, as shown in FIG. 6. 
In this way, for a given maximum telescopic travel, the total axial overall 
size to be prescribed for the tripod element and the roller segments 
corresponds to the length of this travel increased by the distance between 
the surfaces 101a and 101b . No additional size is to be reckoned for the 
roller segments. The overall axial size of the joint is, consequently, 
particularly reduced. 
However, if nothing else is provided, it is impossible to be sure that, in 
operation, the roller segments 6 will actually effect the whole of the 
angular travel about the axis Z--Z when the arms 2 effect their telescopic 
travel. On the contrary, it is to be feared that unwanted sliding between 
the segments 6 and the tracks 9, in particular when the roller segments 
are unloaded, angularly offset the roller segments about the arms 2. As a 
result of such offsets, the roller segments 6 are liable to be interposed 
between the arm 2 and the inner end 20 of the bowl element 10 and thereby 
prevent the arm 2 from reaching its position corresponding to the maximum 
compression of the joint. There is also a risk that they project beyond 
the surface 101b when the arm 2 is in the position corresponding to the 
maximum extension of the joint and thereby damage the rubber bellows or 
gaiter usually provided for connecting the free end of the bowl element 10 
to the periphery of the shaft 4. 
According to the invention, the roller segments 6 on one hand and the bowl 
element 10 on the other hand carry abutment means, 102, 103, 104 which, 
when the arms 2 are substantially at either end of their telescopic 
travel, retain by a mutual bearing relation the roller segments in their 
clearance position. 
In the illustrated embodiment, the abutment means comprise, for each roller 
segment 6, a boss 102 carried by the segment 6 on its outer side, i.e. the 
side remote from the axis X--X . The boss 102, located mid-way 
circumferentially of the segment 6, has a plane of symmetry which is the 
transverse plane of symmetry 106 of the segment 6. The boss 102 has two 
symmetrical abutment surfaces, each composed of two planar faces 107 and 
117, which make an angle E of about 60.degree. (FIG. 2), equal to the 
angular travel of the segment 6 about the axis Z--Z. The two planar faces 
107 and 117 are interconnected by a cylindrical surface 108 having an axis 
substantially parallel to the axis Z--Z when the axes X--X and Y--Y are 
coincident. 
The abutment means pertaining to the bowl element 10 comprise for each 
roller segment 6 two abutment faces 103 and 104 facing each other and 
perpendicular to the axis Y--Y. Each face 103 and 104 is carried by an 
inner projection 109 which is preferably obtained by a localized press 
operation on the inner wall of the bowl element. 
The faces 103 and 104 are located at equal distances from the plane 
perpendicular to the axis Y--Y and passing through the position T1 of the 
center T. In FIGS. 2 and 3, this plane coincides with the transverse plane 
of symmetry 106 of the segments 6. 
Consequently, if a roller segment 6 occupies about the associated arm 2 an 
angular position remote from its clearance position as the arm 2 
approaches one end of its telescopic travel (FIG. 5), the boss 102 comes 
in contact with the corresponding abutment face 103 or 104 of the bowl 
element 10, which prevents the boss 102 from continuing to travel in the 
direction of the end of the travel of the arm. This constrains the roller 
segment 6 to pivot to its clearance position about the arm 2, provided 
that there is a rolling movement without sliding of the toric surface 8 in 
the track and of one of the cylindrical surfaces 108 of the boss 102 
against the abutment face 103 or 104, against which it bears. At the end 
of the movement, when the clearance position is reached, the planar face 
107 adjacent to the aforementioned cylindrical surface 108 comes to bear 
against the abutment face 103 or 104. The position of the faces 103 and 
104 and the angle between each planar face 107 and the plane of symmetry 
are so chosen that when the face 107 bears against the associated abutment 
face 103 or 104, on the one hand one of the cylindrical surfaces 15 is 
connected with the associated rolling track 9, and on the other, hand the 
center T of the associated arm is in the position T2 or T3. Consequently, 
at each end of the telescopic travel, the clearance position of the roller 
segments 6 corresponds to a respective one of their limit angular 
positions about the arm 2. 
Thus when the arm 2 travels toward the inner end 20 of the bowl element 10, 
the cooperation of the bosses 102 and the abutment faces 103, the closest 
to the inner end 20, enable the arm 2 to reach its position T2 
corresponding to the abutment of the end 111 of the shaft 4 against the 
end wall 20. The segment 6 cannot be interposed between the arm 2 and the 
end wall 20, which would prevent the joint from being completely 
compressed. 
Upon an extreme extension of the joint, the abutment faces 104 cooperating 
with the confronting faces 117, 108 and 107 of the bosses 102 constrain 
the segments 6 to take up their clearance position in which they move only 
very slightly out of the bowl element 10, and therefore cannot create any 
hindrance as concerns the presence and the movement of the corrugated wall 
of the elastic sealing bellows. 
Furthermore, as will be understood from FIG. 6, an additional extension of 
the joint is prevented. This is because of the mutual bearing relation of 
the bosses 102 and the abutment faces 104', the segment 6 cannot slide 
further in the direction of extension of the joint. 
Further due to the angular travel limiting means (cylindrical surfaces 15), 
and also because of the mutual bearing relation of the the two segments 6 
by their adjacent ends in front of the face 101a of the arm 2, the 
segments cannot pivot about the arms 2 beyond the clearance position. 
Also, owing to the divergence between the directions L1 and L2, the arm 2 
cannot be disengaged from between the associated segments 6. 
In an intermediate region of the telescopic travel, the abutment means 102, 
103, 104, have no action and therefore allow the roller segments to be 
freely positioned about the associated arm 2 within the angular limits 
defined by the limiting means, which are the cylindrical surfaces 15. The 
intermediate region is intended to mean the telescopic travel that the arm 
2 must effect so that the boss 102 of a segment 6 travels from its bearing 
relation with one of the faces 103 or 104 to a bearing relation with the 
other of these faces 103 or 104 . This intermediate region is variable as 
a function of the angular position of the segment 6 about the arm 2 when 
the boss 102 leaves the position in which it bears against one of the 
faces 103 or 104 and when the boss 102 bears against the other of these 
faces 103 or 104. 
In normal operation, the arm 2 is located in the intermediate region of its 
telescopic travel, the roller segments 6 are also in an intermediate 
angular position between the limit angular positions, and telescopic 
movements of small extent are effected by rolling without sliding of the 
roller segments 6 in the tracks 9. 
In the embodiment shown in FIGS. 7 to 10, the outer wall of the roller 
segments 6 only has the toric region 8. The boss 102 carried by each 
segment 6 has an active surface composed of two planar faces 118 and 118 
which are symmetrical relative to the plane 106 and make an angle of about 
120.degree. and are substantially parallel to the axis Z--Z when the axes 
X--X and Y--Y are coincident. 
The joint further comprises three intermediate means which, in the 
illustrated embodiment, are the three branches 112 of a clip 
interconnected by a base 113 of the clip facing the free end 111 of the 
first element (to which the tripod element pertains). The clip is made 
from a metal sheet which is cut or blanked out, bent and hardened. Each of 
the branches 112 extends between two rolling tracks 9 on which bear 
rolling segments associated with the same arm 2 of the tripod element. 
There is therefore one pair of rolling tracks 9 in each circumferential 
gap between two successive intermediate means. In this embodiment, the 
abutment means 102 of the roller segment 6 cooperate only indirectly with 
the abutment means of the bowl element 10, i.e. they cooperate with 
abutment surfaces 203 and 204 carried by the intermediate means 112 which 
in turn cooperate with the abutment means of the bowl element 10. 
In this embodiment, the intermediate means 112 are fixed in the bowl 
element 10. For this purpose, the base 113 bears against the inner wall 20 
of the inner end of the bowl element 10, which thus constitutes one of the 
abutment surfaces of the bowl element 10, while the ends of a free edge 
114 opposite the base 113 of each intermediate means, or branch, 112 are 
clipped behind shoulders 116 facing toward the inner end 20, and provided 
in the inner wall of the bowl element 10, and thus constitute other 
abutment means against which the bosses 102 bear indirectly through the 
branches 112 when the associated arms 2 reach the position corresponding 
to the maximum extension T3 of the joint. 
Each branch 112 presents to each adjacent roller segment 6 two abutment 
surfaces 203 and 204 which have, relative to a plane perpendicular to the 
axis Y--Y (plane 106 in FIG. 8B) an inclination of about 30.degree., so 
that a respective one of the planar faces 118a or 118b bears flatly 
thereagainst when the roller segment is in the corresponding clearing 
position (see FIG. 8A and FIG. 9B). 
As an angular travel limiting means, each branch 112 has, for each 
associated roller segment 6, an abutment edge extending in a direction 
parallel to the axis Y--Y between the surfaces 203 and 204 associated with 
the same segment. As shown in FIG. 9A, the abutment edges 119 receive in 
sliding relation thereto either of the planar faces 118a or 118b of the 
bosses 102 when the roller segments 6 are in, respectively, one or the 
other of their limit angular positions about the arms 2. Bearing in mind 
the angle of 120.degree. between the planar faces 118a or 118b, the 
allowed angular travel of the segments if 60.degree., which is the 
rotation to ensure that a boss 102 moves from the position in which its 
planar face 118a bears against the edge 119 to the position in which its 
planar face 118b bears against the edge 119. The concave angle formed by 
the edge 119 with each abutment surface 203 and 204 is equal to the convex 
angle of the two planar faces 118a and 118b of each boss 102, so that at 
each end of the telescopic travel of an arm, one of the planar faces 118a, 
and 118b of each segment 6 bears against the corresponding abutment 
surface 203 or 204, and the other against the abutment surface 119. 
With reference to FIG. 9A, when the center of the arm 2 occupies the 
position T4 and travels toward the limit position T2 and the roller 
segment 6 already occupies the limit angular position corresponding to the 
clearance position for the end of the travel T2, the planar face 118b of 
the boss 102 slides along the longitudinal abutment surface 119 of the 
clip until the other planar face 118a of the same boss comes to abut 
against the abutment surface 203 of the clip when the center of the arm 
reaches the position T2 (right part of FIG. 9B). 
FIG. 11 is common to the two embodiments shown in more detail in FIGS. 12 
to 24. These embodiments also employ an intermediate means 212 
constituting the branches of a clip interconnected by a base 113 (FIG. 13) 
located between the tripod element and the inner end of the bowl element 
10. However, the branches 212 now extend in the section S (shaded in FIG. 
11) located between the adjacent rolling tracks 9 against which bear 
roller segments 6 associated with different arms 2 of the tripod element. 
In other words, the branches 212 are located between the ring 1 and the 
bore 121 of the heel between two tracks 9 cooperating with the different 
arms 2. In this way, the branches 212 are at a distance from the axis Y--Y 
which is reduced by about 20 mm. 
Under these conditions, in order to allow the free angular movement of the 
shaft 4 when the joint is completely compressed (T2 in FIG. 13), it is 
necessary to arrange that the abutment surfaces 204 against which the 
bosses 102 bear in the other extreme position (position T3 in FIG. 13) 
are withdrawn so that they do not interfere with the shaft 4, which during 
the rotation of the joint at a flexing angle describes, with respect to 
the bowl element 10, a conical surface centered at T2 and having a 
semi-angle at the center which is equal to the operating flexing angle of 
the joint, i.e. the angle between the axes X--X and Y--Y (such as the 
angle A in FIG. 3). 
In the two embodiments shown in FIGS. 11 to 24, the segments 6 are of the 
type shown in FIGS. 14 to 16. They are identical to the segments shown in 
FIGS. 1 to 3 except that the boss 102 has two opposed parallel planar 
faces 123 which are parallel to the plane 106 in FIG. 15 and 
interconnected by a semi-cylindrical surface 122 facing away from the axis 
Z--Z, and are substantially parallel to the latter when the axis X--X of 
the tripod element and the axis Y--Y of the bowl element 10 are 
coincident. 
The toric rolling region subtends an angle B of about 60.degree.. The inner 
spherical bearing region 124 subtends an angle C of about 120.degree.. 
The clip having three branches 212 (FIGS. 17 and 18) is obtained by 
blanking, press forming and hardening a steel sheet. The three branches 
have a U-sectioned shape which is open toward the axis Y--Y, and the base 
113 is substantially triangular. 
The wings of U--shaped section are locally notched to provide sliding 
abutment surfaces 203 and 204, which are inclined at 60.degree. to the 
axis Y-Y. Thus, when the segments 6 are in their limit angular position 
and the bosses 102 are in contact with an abutment 203 or 204, one of the 
planar faces 123 bears flat against the abutment. 
The clip axially floats within the bowl element 10. For this purpose, the 
back of the U-sectioned shape of each of the three branches is axially 
slidable on the bearing surfaces formed by the bore 121 between the tracks 
9 associated with the different arms 2. 
Each branch 212 carries on its rear side in the vicinity of its free end a 
lug 126 which is press-formed when forming the clip. This lug defines a 
step 127 which is perpendicular to the axis Y--Y and faces away from the 
base 113. An extreme position of extension of the clip relative to the 
bowl element 10 is defined by the clipping of the step 127 in a notch 128 
which has a substantially complementary contour and is formed by a turning 
operation in the bore 121 of the bowl element in the vicinity of the 
opening of the latter. In particular, the notch 128 has a surface 116 
facing toward the inner end 20 of the bowl element and constitutes one of 
the abutment means related to the bowl element. 
Consequently, when the arm 2 reaches its limit position T3 (FIG. 13), the 
boss 102 bears against the surface 204 and in this way constrains the 
segment 62 to take up its clearance position, while the displacement of 
the clip toward the opening of the bowl element 10 is limited by the 
bearing of the step 127 of the branches 112 against the surface 116 of the 
notches 128. In this position, two ends 129 of the two segments associated 
with each arm are in abutting relation to each other. 
In the other extreme position of the arm, the boss of each segment 6 bears 
against the other abutment surface 203 of the branches 112. The segments 6 
are in their clearance position, in abutting relation to each other at 
their two other ends. The displacement of the clip toward the interior of 
the bowl element 10 is limited by the bearing of the base 113 against the 
inner end wall 20 of the bowl element, which constitutes the other 
abutment means related to the bowl element 10 (see position T2 of FIG. 
13). 
The lugs 126 and the notches 128 have opposite their step 127 and shoulder 
116, respectively, surfaces 131 and 132 having complementary slopes 
permitting the lugs 126 to leave the notches 128 in the direction toward 
the inner end of the bowl element by a bending of each arm relative to the 
base 113. Thereafter, and up to the position of maximum compression T2, 
the clip is guided in the bore 12 in the region of a back 133 of the lug 
126 and in the region of a beginning portion 134 of the bend connecting 
the branches 212 to the base 113. 
In operation of the joint, the telescopic movement between the positions T4 
and T5 can occur by a rolling of the segment 6 on the rolling track 9 of 
the bowl element without displacement of the floating clip. The boss 102 
has, between the surfaces 203 and 204, sufficient clearance for this 
purpose. Such a travel corresponds to the usual needs in normal use of the 
joint. 
In exceptional circumstances, when an additional sliding is required, the 
segment 6 slides on the rolling track 9, bearing against one of its 
cylindrical regions 15, and axially shifts the floating clip up to 
position T2 in compression or T3 in extension of the joint. 
The total telescopic travel is therefore equal to the 15 distance T2-T3. 
The joint is assembled, with no special arrangement, by inserting in the 
barrel element the shaft 4 on which is fixed the tripod element provided 
with its six roller segments 6 and capped with the floating clip 212, 113 
(as shown in FIGS. 12 and 13 for the positions T1, T2, T4, T5). The ends 
of the branches 212 of the clip slightly bending inwardly about elastic 
bending axes 136 of planar regions of the base 113 (FIG. 17). 
For taking the joint apart, it is sufficient to slip, in position T3, the 
end of a screwdriver between the end 127 of the branches 212 and the 
chamber 138 of the bowl element 10 to unclip the clip (FIG. 13) and 
release the shaft 4 equipped with the tripod element, the segments 6 and 
the clip. 
The embodiment shown in FIGS. 19 to 24 will only be described with respect 
to its differences from the preceding embodiment. 
The lug 126 for axially retaining the clip is press-formed close to the end 
of the branches 212 at which the latter are connected to the base 113. 
Consequently, the lug 126 cannot be radially withdrawn, since it is 
located substantially in the plane of the base 113 of the clip. An 
abutment ledge 139 is advantageously inclined at 45.degree. to facilitate 
the cold forming thereof. 
A back surface 141 of each branch is slidable within the bore 121 of the 
bowl element. A radially outermost part 142 of the press-formed lug 126 is 
guided inside a counterbore 143, which extends approximately in one half 
of the length of the rolling tracks between the inner end 20 of the bowl 
element 10 and a step 144 inclined at 45.degree.facing the inner end 20. 
FIG. 19 shows the clip in its outermost position relative to the bowl 
element 10. The arm, in position T3, and the roller segments 6 are shown 
in dot-dash lines. The clip alone is shown in dot-dash lines in the 
innermost position thereof at the top left of FIG. 19. The operation for 
the various circumstances relating to positions T0 to T5, is substantially 
the same as in the preceding embodiment. 
In the outermost position of the clip relative to the bowl element, the 
abutment ledge 139 of the lug 126 abuts against the step 144, which 
constitutes one of the abutment means of the bowl element 10. 
The abutment in the innermost position of the clip in the bowl element 
occurs simply by the bearing of the base 113 against the inner end 20, 
which constitutes the other abutment means of the bowl element. 
FIGS. 21 to 23 show the principle of the assembly of this embodiment of the 
floating clip. 
The diameter of the circumference circumscribing the radially outermost 
parts 142 of the lugs 126 is a few millimeters larger than the bore 121. 
The clip is engaged in the bowl element after a rotation on the order of 
5.degree. to 10.degree. relative to the bowl element about the axis Y--Y. 
As shown in the upper part of FIG. 23, the lugs 126 place themselves in 
the available space radially against the chamfered edges of the rolling 
tracks 9, and the clip, together with the assembly of the shaft 4, the 
tripod element and the roller segments 6, are engaged until the position 
shown in FIG. 21 is reached. In this position, the roller segments 6 take 
up a tangent position relative to the outer wall 146 of the U-sectioned 
shape of the end of the branches 112 of the clip. This wall 146 partly 
encumbers the entrance of the rolling track 9 owing to the aforementioned 
rotation through 5.degree. to 10.degree.. An axial compression force is 
then exerted on the assembly and this has for effect, by forcing the toric 
surfaces 8 of the segments 6 to enter their rolling tracks 9, to exert a 
bending moment on the branches 212 of the clip. These branches bend 
elastically due to the relative torsional flexibility of the shaded 
section 147 of their base 113 about the axes OP, OQ and OR (FIG. 20) by 
inclining, in accordance with helices having a very large pitch on the 
general axis Y--Y, as shown diagrammatically in FIG. 23. The assembly then 
slides toward the interior of the bowl element 10 and the clip expands and 
resumes its normal configuration as soon as the lugs 126 reach the 
counterbore 143. 
The sliding assembly is in this way positively locked within the bowl 
element 10, as shown by the lower part of FIG. 23 and FIG. 19. 
The joint is disassembled by unlocking the clip. The tripod element is 
placed in the position T3 (FIG. 19). A screwdriver 148 is inserted inside 
the U-shaped contour of the branches of the clip (FIG. 23). As the bowl 
element 10 is fixed, a bending moment is applied to each of the branches 
by means of the screwdriver about the axis 149, while exerting a pull on 
the shaft 4 of the tripod element. The base 113 of the clip and the three 
lugs 136 turn, as shown in the upper part of FIG. 23, and the assembly 
comprising the shaft, the tripod element, the roller segments and the clip 
can be extracted from the bowl element without difficulty. 
The press-forming of the floating clips with their lugs is easily carried 
out on a blank cut or blanked from sheet steel by means of a simple and 
conventional forming tool, diagrammatically shown in FIG. 24. 
To this end, the press-forming is carried out with the branches opened at 
an angle D of 45.degree. to 60.degree. by folding at 151 the base about 
the axes 136 (FIG. 17) or the axes of the regions 147 (FIG. 20), which 
permits the easy forming of the lugs 126 and the ledges 139, which are 
undercut in the finished part. 
After press-forming, the folds 151 are straightened and the clip is 
terminated and ready to be hardened. 
In each of the embodiments just described, the centrifugal force due to the 
rotation of the joint about its axes X--X and Y--Y, which may be 
coincident, urges the roller segments 6 toward an intermediate angular 
position termed the "neutral" position located angularly midway between 
the two limit angular positions. 
This return is in particular effective for the segments 6 which are 
non-loaded, depending on the direction of the torque. 
As shown in FIG. 25, for the purpose of increasing the return effect in 
respect of the segments 6 which are under load, it is advantageous to 
arrange that the center U of their inner spherical bearing surfaces have, 
relative to the axis T--T of the toric surface 8, a slight offset or 
ecccentricitye of a fe tenths of a millimeter in the direction toward the 
considered segment 6, along the direction Bo, which is at the intersection 
of the plane 106 and a longitudinal median plane of the segment 6. 
Thus, the thickness, or the radial dimension, of the segment 6, is slightly 
smaller in the circumferential middle, than at the two ends B1 and B2 of 
the angle B of the toric region 8, and gradually increases on each side of 
the plane 106 toward the ends B1 and B2. 
This offset has the effect of creating a centering return when the segment 
is loaded, without the very slight increase in thickness at the ends B1 
and B2 presenting any drawback. 
FIG. 25 represents in a very exaggerated manner this 10 offset. For 
example, an offset "e" of 0.3 mm when the spherical bearing surface has a 
radius of 16 mm creates at the ends of the angle B a radial thickening "h" 
of about 0.04 mm. 
The return slope at the ends of the angle B is about 1% and produces a 
return force F of 5 kg for a load of 500 kg on the segment. 
Consequently, during the operation of the joint, the segments always tend 
to resume a zero inclination, which has the advantage of conserving the 
availability of the whole of the rolling travel. 
To summarize, it is found that the devices of the described invention have 
the following advantages: the combination angularity/sliding has the most 
extended diagram of utilization for a given axial size and diameter of the 
barrel element. The conventional system for preventing the joint from 
coming apart by means of a cap which is set in position is replaced, the 
overall size of the joint is reduced and the risks of leakage and damage 
to this cap are eliminated. The operation of the device is absolutely 
reliable. The assembly and disassembly of the joint is failed. The 
production and assembly of the device can be achieved at a low cost.