Universal connection unit

The invention relates to a connection unit of universal type. This comprises two complementary connection elements (1,2) with a coaxial structure having at least one peripheral part and a central conductive core. The peripheral part(s) of one of the connection elements (1) are in sleeve form. The sleeves (10) and the contact (11) are mounted movably in translation in the direction of the longitudinal axis .DELTA. of the male element (1). The sleeves (10) and the contact (11) are mechanically independent. The connector of this invention has application to connectors for radio frequency and/or numerical or analog signals.

BACKGROUND OF THE INVENTION 
The present invention relates to a universal connection unit with a coaxial 
structure. 
The connection units with coaxial structure presently used are constituted 
by two plugs, a male plug and a female plug, the connection-disconnection 
of these being effected by slidingly plugging in/out. In general, these 
connection units are used either for connection by means of coaxial 
cables, for the transmission of radio-electric signals, or for the 
connection of cables with two twisted conductors having peripheral 
screening for the transmission of numeric or analog signals. In all cases, 
the connection-disconnection is effected by slidingly plugging in/out the 
male plug into the female plug. 
Such connection units, although they permit good electrical transmission 
characteristics of these signals, particularly with low attenuation of the 
signal transmitted over a wide band of frequencies, have nevertheless 
inconveniences which relate to the risk of wear of the parts in electrical 
contact due to numerous connections/disconnections. Further, the 
arrangement of the connectors having a plurality of plugs of this type, 
particularly in the case of chassis connectors able to be plugged in known 
as "rack" connectors, have the major inconvenience of needing significant 
extraction forces for the operation of numerous cycles of 
connection-disconnection. 
THE INVENTION 
The present invention has the object of remedying the mentioned 
inconveniences by providing a connection unit with a coaxial structure of 
universal type. 
Another object of the present invention is to provide a connection unit 
able to permit the transmission of electric signals of any type either 
continuous, pseudo-continuous or slowly varying signals, or radio-electric 
signals of very high frequency, preferably microwave signals, with a very 
low attenuation in transmission. 
Another object of the present invention is to provide a connection unit for 
which the connection/disconnection operation is effected with a very low 
extraction force for disengagement. 
Another object of the present invention is the provision of a connection 
unit for which numerous cycles of connection/disconnection are effected 
practically without noticeable wear of the electric contact points, each 
operation of connection/disconnection being effected substantially without 
tangential friction force of the mentioned parts. 
Another object of the present invention is in fact the provision of a 
connection unit for which the contact pressure of the parts in electric 
contact is substantially constant with time and the wear caused by a 
significant number of connection/disconnection cycles, although very low, 
is further reduced by removing the play between the parts in electrical 
contact. 
The universal connection unit with a coaxial structure according to the 
invention comprises two complementary connection elements. Each connection 
element has at least one peripheral part forming a connection part and a 
central core constituted by a contact electrically insulated from the 
peripheral parts. According to the invention, the peripheral part(s) of 
the male connection element, is in sleeve form, the sleeves and the 
contact being mounted movably in translation in the direction of the 
longitudinal axis of the male element. The sleeves and the contact are 
mechanically independent. 
The connection unit of the invention finds application in the 
radio-telephone field, the transmission or the reception of numeric data 
represented in the form of electrical signals, the informative material 
for which the connection unit of the invention can advantageously be used 
in the production of chassis connectors.

FIRST EMBODIMENT 
According to FIG. 1a, the connection unit comprises two complementary 
connection elements referenced respectively 1 and 2. Each connection 
element comprises at least one peripheral part referenced 10 for the 
connection element 1 and 20 for the connection element 2 forming the 
connection part and a central core referenced 11 and 21 respectively 
constituted by a contact electrically insulated from the corresponding 
peripheral parts. In FIG. 1a is shown a connection unit according to the 
invention more specially adapted to the connection of coaxial cables 
comprising a central conductor and a peripheral screen principally used 
for the transmission or reception of radio-electric signals. 
According to the invention, and in the particular case of FIG. 1a, the 
peripheral part 10 of one of the connection elements, the element 1 in 
this case, as in the form of a sleeve, the contact 11 and the sleeve 10 
being mounted movably in translation in the direction of the longitudinal 
axis .DELTA. of the connection element 1. The sleeve 10 and the contact 11 
are mechanically independent of each other. The connection element 1 is 
called the male element. In contrast to this designation, the connection 
element 2 is called the female element and is constituted by a contact 21 
constituting the central core and by a sleeve 20 forming the peripheral 
part of the connection element 2 in the case of the nonlimiting embodiment 
of FIG. 1a. Of course, the contact 21 and the sleeve 20 of the female 
connection element have substantially identical electrical sections and 
dimensions, in a plane perpendicular to the longitudinal axis .DELTA. of 
the connection unit, in comparison with those of the male element. 
Electric sections and dimensions refers to the diameter of the contact 
section forming the central core, and the internal diameter of the sleeves 
10 and 20 of the male and female connection elements which define the 
propagation parameters of radio-electric signals of high frequency or 
hyper-frequency transmitted by the connection element. 
The electric connection between the two connection elements, the male 
element 1 and the female element 2, is made by bringing into flush 
abutment of the peripheral parts or sleeves 10,20 and respective contacts 
11,21 of the male 1 and female 2 connection elements respectively. 
It will be understood that the male or female designation of the connection 
elements is a designation having the object of differentiating each 
constituent connection element of the connection unit of the invention, 
although the connection/disconnection of the mentioned unit is in fact 
carried out without reciprocal plugging in/out of the connection elements 
1 and 2. 
The connection elements 1 and 2 are connected together by bringing into 
flush abutment the corresponding parts of the connection elements 1 and 2, 
with a sufficient alignment as determined by the the manufacturing and 
assembly tolerances of the mentioned mechanical pieces, along the 
respective longitudinal axes of the male and female connection elements 1 
and 2. 
In order to ensure a substantially constant contact pressure between the 
corresponding peripheral parts and the contact forming the central core of 
the connection elements 1 and 2, the sleeve 10 and the contact 11 of the 
male connection element 1 are provided with elastic return means allowing 
mechanical and electrical contact with the peripheral part 20 and the 
contact 21 respectively of the female connection element 2. The elastic 
return means can be constituted by springs referenced 100, 110 and acting 
respectively on the sleeve and the contact 11. 
SECOND EMBODIMENT 
A variant or second embodiment of the universal connection unit of the 
invention, will now be described in connection with FIG. 1b in the case 
where each male 1, female 2, connection element comprises a plurality of 
peripheral parts in order to ensure, via the intermediary of these 
peripheral parts, either screening of the totality or a part of the 
correpsonding connection element, or transmission of a current or voltage 
signal given by the connection of the peripheral part corresponding to a 
predetermined conductor constituent of the cable to the connection unit. 
In FIG. 1b, is shown a connection unit according to the invention in which 
each male 1, female 2, connection element comprises two peripheral parts 
each constituted by sleeves arranged concentrically to the contact 11 
constituting the central core. In FIG. 1b, the sleeve situated in the 
immediate proximity of the contact 11 is referenced 10 in an analogous 
manner to FIG. 1a, whilst the sleeve the furthest outside with respect to 
the male connection element 1 is referenced 14, the corresponding sleeves 
of the female connection element 2 having in an analogous manner the 
references 20 and 24. Of course, the sleeve 14 of the male connection 
element 1 is provided with elastic return means in a manner analogous to 
the sleeve 10. These elastic means are also constituted by a spring 
referenced 140 and allow the mechanical and electrical contact of the 
sleeve 14 with the corresponding sleeve 24 of the female connection 
element 2 by bringing them into flush abutment. 
Embodiment details relative to the connection units according to the 
invention so far as concerns the embodiment of FIG. 1a as well as FIG. 1b 
will be given by way of nonlimiting examples. 
As shown in the mentioned Figures, the male connection element 1 comprises 
for example a cylindrical insulating body 12 mechanically fixed to the 
body of the male connection element 1. In this cylindrical insulating body 
is mounted slidingly on the longitudinal axis the contact 11 forming the 
central core. Further, a tubular conductor element constituting the sleeve 
10 in the case of FIG. 1a is slidingly engaged on the insulating 
cylindrical body 12. The tubular conductor element has in a plane 
perpendicular to its lengthwise direction a rib or shoulder referenced 
101. In the case of FIG. 1b, a second tubular element constitutes the 
sleeve 14 and is slidingly engaged on another insulating cylindrical body 
13. The tubular conductor element constituting the sleeve 14 also has in a 
plane perpendicular to its lengthwise direction a rib or shoulder 
referenced 141. The springs 100 and 140 are respectively engaged on the 
sleeves 10 and 14 and act on these via the intermediary of corresponding 
ribs 101, 141 and of a fixed conducting part referenced 102, 142, 
constituted for each sleeve 10 and 14 and also by a tubular conductor 
element fixed in the male connection element 1. The springs 100 and 140 
bear on the corresponding fixed parts 102 and 142, which further assure 
the mechanical cohesion of the cylindrical parts 12 and 13 respectively. 
Further, in the case of FIG. 1b, the cylindrical element or insulating 
cylindrical body 143 surrounds the sleeve 14 and the fixed part 142 the 
furthest outside in a manner to ensure the mechanical cohesion of the 
assembly. Of course, the insulating cylindrical bodies 12,13 and 143 in 
the case of FIG. 1b are adapted in a manner to define with the ribs 
101,141 and the fixed parts 102,142 housings in which the springs 100 and 
140 are mounted. Further, the parts of the sleeves 10 and 14 on which the 
springs 100, 140 are engaged are constituted by a slit sleeve having a 
plurality of elastic blades extending longitudinally of the axis .DELTA. 
of the male connection element 1. Thus, on positioning and making contact 
by flush abutment of the male connection element 1 and of the female 
connection element 2, the movable contact parts constituted by the contact 
11 forming the central core, the sleeve 10 and, in the case of FIG. 1b, 
the furthest outside sleeve 14 are pushed inside the body of the male 
connection element 1, the elastic force of the springs maintaining 
suitable contact pressure on the corresponding parts of the female contact 
element 2. It will be noted in particular that the electric contact 
between the sleeves 10 and 14 and their fixed corresponding parts 102, 142 
is brought about with good electric continuity even at the highest 
frequency because of the presence of elastic blades forming the slit 
sleeve and of the compressed springs. 
As concerns the contact 11 forming the central core, this can, as shown in 
FIGS. 1a and 1b, comprise a substantially cylindrical connection base 
having a shoulder 112. The connection base and the shoulder 112 are 
embedded in the insulating cylindrical body 12 in a manner to leave free 
on one end a connection zone 113 outside the insulating cylindrical body 
12 intended to receive a conductor of the cable to be connected and on the 
opposite end inside the housing of the cylindrical body 12 a contact 
needle referenced 114. The contact 11 forming the central core further 
comprises a cylindrical element 115 comprising in a plane perpendicular to 
its lengthwise direction a shoulder referenced 116. The opposite part, 
with respect to the shoulder 116, to the part of the cylindrical element 
115, forming an active part of the contact 11, is constituted by an 
element of the slit sleeve type 117. The spring 110 acting on the contact 
11 is engaged on the slit sleeve 117 and on the contact needle 114, 
between the shoulders 116, 112 respectively of the cylindrical element 115 
and of the connection base 111 on which the spring 110 abuts. The contact 
needle 114 is thus able to be engaged in the slit sleeve 117 on connection 
of the connection unit. 
The connection element 2 shown in either FIG. 1a or FIG. 1b, can be 
constituted simply by a cylindrical element 21 constituting the contact 
forming the central core of the element of the female connection 2, and 
the peripheral parts 20 and/or 24 constituting tubular conductor elements 
of the sleeve type, the assembly of the contact 21 and the tubular 
conductors 20,24 being embedded in a block of insulating material 23 and 
being brought into flush abutment simply with the free face of insulating 
block 23. 
In a nonlimiting manner, the peripheral parts and the central core 
respectively referenced 20,24 and 21 of the female conductor 2 can 
advantageously be produced by conductor elements of printed circuits in 
which the dimensions are configured to the respective dimensions of the 
conductive parts of the male connection element 1. 
The assembly of the conductive parts of the elements of the male connection 
1 and female 2, that is to say contact element 11 and connection base 111, 
sleeves 10, 14 and fixed parts 102,142, contact needle 114, and of the 
female connection element 2, contact 21 forming the central core, 
peripheral part 20,24 can be constituted in a nonlimiting manner in an 
alloy of copper having a covering of gold or silver. The insulating parts 
12,13,143,23 can preferably be constituted in a dielectric material with a 
small loss angle such as for example polytetrafluorethylene. As concerns 
on the contrary the elastic elements, for example the springs 100,110 and 
140, these can, preferably, be constituted in a material such as an alloy 
of copper and beryllium providing the springs with good properties of 
elasticity. Further, preferably, the housings constituted essentially by 
the cylindrical insulating elements, the shoulders or ribs 141,101,116 and 
the fixed parts 142, 102,112 can advantageously be formed in a manner to 
have a longitudinal dimension, that is to say a dimension in the direction 
parallel to the axis .DELTA., such that in a connection position, the 
assembly of mentioned springs is deformed by compression in a manner such 
that their spirals are closed. This particular arrangement has the effect 
of presenting, particularly at the level of the wall constituted by the 
closed spirals of the spring a quasi continuous wall presenting good 
conditions to limits of propagation of radio-frequency signals. It can be 
stated, in the course of experiments carried out, that, particularly in 
these conditions, the part of the sleeves 14 and 10 constituted by the 
slit sleeve, that is to say by the elastic blades, withstood usage without 
major degradation in transmission quality. 
From frequency experiments relative to the transmission from a connection 
unit such as shown in FIG. 1a, the sleeve 10 and the corresponding fixed 
part 102 being connected by connection pins 1021 to the screen of a 
coaxial cable and the connection zone 113 being connected to the central 
core of the same cable, have shown an insertion loss less than one decibel 
over a frequency band in the ratio of 10 for a maximum neighbouring 
frequency greater than 1 GHz. 
A detailed description of the rear part of the connection unit according to 
the invention as shown in FIG. 1b will now be given in connection with 
this figure. As appears in this figure, the fixed part 142 of the furthest 
outside sleeve of the male connection element 1 is provided with terminals 
or contact zones 1421. In the same manner, the fixed part 102 of the 
intermediary sleeve is provided with terminals or contact zones 1021 and 
the connection base 111 is itself provided with a connection zone 113. As 
appears in this Figure, it will be noted that the connection terminals 
1421,1021 and 113 have, in this order, an ascending length parallel to the 
axis .DELTA. of the male connection element 1. Further, one of the 
connection terminals 1021 can be provided with a base intended to receive 
directly a cable conductor to be connected in a manner permitting the 
connection of this by crimping or by deposit of metal. In the embodiment 
of FIG. 1b, this base is designated 1020. Similarly, the connection zone 
113 is also provided at its outside with a base intended to receive a 
cable of a conductor to be connected, in a manner to be able to effect a 
connection of this cable onto the base by crimping or by deposit of metal. 
In FIG. 1b, the cable connected to the base 1020 is referenced 17 and the 
cable connected to the base of the terminal or connection zone 113 is 
referenced 16. Similarly, the peripheral screen of the cable or metallic 
braid is referenced 18. The mechanical and electrical connection of the 
metallic braid 18 is made by means of an auxiliary piece or nut 144, 
directly engaged by screwing the shell or protective body 15 or more 
particularly on a first part 15A of the protective body 15. The first part 
15A of the protective body 15 is fixed to the insulating material block or 
insulating cylindrical element 143 by the intermediary of an assembly of 
grooves referenced 153 arranged inside the part 15A of the protective body 
and corresponding ribs 150 arranged specially for this in the region of 
the periphery of the insulation cylindrical element 143. After positioning 
the conductors 16,17,18 on their respective terminals or connection zones 
by crimping or deposit of metal as concerns the conductors 16 and 17, the 
screen or metallic braid being held in contact on the corresponding 
terminals 1421, the auxiliary piece 144 can be engaged in the 
corresponding thread of the part 15A of the protective body and tightened 
in a manner to ensure the mechanical cohesion of the metallic braid 18 
with the contact zones 1421 and their electrical contact. Then, the 
complementary part 15B of the protective body can be engaged on the 
corresponding threading 151 in a manner to close the protective body 15. 
The fluid-tightness of the protective body, in the region of the connected 
cable, can further be effected by means of a point or pressure stuffing 
152 which comes into direct contact with the insulation or sheath of the 
connector cable 19. 
It will be noted in particular due to the structure of the rear part of the 
connection unit, shown in FIG. 1b, that this can be used in an 
advantageous manner either for the connection of a cable to be connected 
having two twisted conductors 16,17 and a peripheral screen 18, or simply 
a coaxial cable having a central core and a peripheral screen. In this 
latter case, the central core is directly connected to the connection base 
of the connection zone 113 and the peripheral screen such that the braid 
18 can then be connected onto the terminals or connection zones 1021 
connected to the fixed part 102 of the sleeve 10, the base 1020 being for 
example sectioned for its suppression. The mechanical cohesion an the 
electric contact between the braid 18 and the terminals or contact zones 
1021 can be effected by an auxiliary conductive piece 144, similar to the 
auxiliary conductive piece previously described, of which the dimenisons 
have been adapted to the corresponding dimensions of the fixed part 102 
and of the connection or contact zones 1021. Further, the electric contact 
can be ensured by simple mechanical and electrical contact between the 
adapted auxiliary piece 144 and the contact zones or terminals 1421 fixed 
to the fixed part 142 of the outermost sleeve 14. 
Further, the connection unit shown in FIG. 1b advantageously permits, due 
to its structure, the connection of coaxial cables having a central core 
and two concentric screens. 
FIG. 1c shows a rear view of a connection unit of FIG. 1b, in which the 
part of the protective body 15B and 15A as well as the auxiliary piece 144 
are removed in the absence of conductors of the cable to be connected. In 
this figure, the relative arrangement of the connection zones or terminals 
1021, 1421, 113 and the connection bases 1020 are shown. It can be stated 
in particular that the assembly of the male connection unit 1 is 
substantially symmetrical in revolution about the axis .DELTA.. It will be 
understood in particular that in the embodiment of FIG. 1b, the electric 
dimensions of the contact 11 of the sleeve 10 of the insulating 
cylindrical element 12, of the contact 21 of the peripheral part 20 can 
advantageously be chosen identical to those of a connection unit as shown 
in FIG. 1a. In these conditions, the conditions of propagation of 
radio-electric signals, when the connection unit as shown in FIG. 1b is 
used for connecting of a coaxial cable, remain substantially analogous to 
those obtained in the conditions of use of the connection unit such as 
shown in FIG. 1a. It will be understood in consequence that the connection 
unit, the object of the invention, shown in FIG. 1b, can advantageously be 
utilized either for the connection and joining of cables with two twisted 
conductors having a peripheral screen, or for the connection and joining 
of coaxial cables justifying in this the universal character of the 
connection unit of the invention. 
The connection unit according to the invention, such as defined previously, 
can be advantageously used for production of connectors having at least 
one male connection element 1 constituting the male part of the connector. 
The female part of the connector comprises at least one female connection 
element 2. 
As shown in FIGS. 2a and 2b, in the case of a connector for a chassis, the 
male and female connection elements are arranged in a block of insulating 
mterial constituting the male and female parts of the connector body. The 
male and female parts of the connector body are provided with means for 
centering and fixing. The male part of the body of the connector as shown 
in FIG. 2a can comprise in a nonlimiting manner guiding columns 1200 and 
fixing bolts 1201. Similarly, the female part of the connector body shown 
in FIG. 2b, can comprise grooves or slide guides 200, in which, for making 
the connection, the guide columns 1200 of the male connector part are 
engaged. Further, screw threads 201 are provided opposite the fixing bolts 
1201 of the corresponding male part. The columns 1200 having been engaged 
in the slides 200 in order to effect the connection and the necessary 
contact pressure being established, the screwing into position of the 
connection is then carried out by screwing of the bolts 1201 into the 
corresponding threads 201. The centering obtained in the region of each of 
the connection units of the invention constituting the connector is quite 
sufficient for ensuring the connection at the level of each connection 
unit, taking account of manufacturing tolerances and normal machining of 
the connecting material, whatever the use of the connection units for the 
transmission of radio electric signals or numeric or analog signals, as 
previously described. It can simply be added that experiments carried out, 
as regards the stability with time of the contact force or the conductance 
in the region of each of the contacts, of a connection unit of the 
invention have shown an excellent constance of stability after repetition 
of a connection/disconnection cycle greater than several thousand.