FR2622363A1 - Polarisation system for the attachment of the plug and socket of a multi-contact rectangular electrical connector - Google Patents

Abstract

In order to prevent connection errors when several sockets PF of multi-contact rectangular connectors are mounted on the one same plate PS, a polarisation system is associated with each of the sockets PF and plugs PM, this system comprising principally a U-clamp 10 and two coding keys 30. The latter serve both to code the plug or socket and to fasten the plug or socket to the U-clamp 10 and, depending on whether it is a socket or a plug, to the plate PS or to a cable clamp SC. Captive screws 42 mounted in the U-clamp 10 associated with the plug PM subsequently enable the latter to be fastened to the U-clamp associated with the socket PF. The U-clamps 10 are all identical. Such a system is advantageously used in the aeronautical and computing industries.

Description

MISCELLANEOUS ASSEMBLY FOR FIXING THE SOCKETS OF A
MULTI-CONTACT RECTANGULAR ELECTRIC CONNECTOR
DESCRIPTION
The invention relates to a polarizing assembly designed to secure the male and female sockets of a multicontact electrical connector of approximately rectangular shape.

In the aeronautics and IT industries, iL frequently happens that several identical multicontact connectors such as "D" connectors
SUBMINIATURE "(defined by MIL C.24308) are located in the same area. In particular, for functional reasons of circuit separation, eight to fifteen identical fixed sockets, connected by cable harnesses to computers or shelves with electrical equipment to supply, are often grouped on the same electrical connection board, electrical connection is ensured later by plugging mobile sockets on these fixed sockets previously connected to cable harnesses in a rearing workshop.

 Most of the rectangular multi-contact electrical connectors usually used in the aeronautical and computer industries do not currently include any keying device allowing the user to avoid the swapping of mobile sockets during connection.

 When the mobile sockets are connected to the fixed sockets, there is therefore a significant risk of connection errors. This can have serious consequences since the involuntary exchange of two mobile sockets can cause considerable damage when powering up, up to the complete destruction of certain circuits such as computers.

 To overcome this drawback, there are currently polarizing devices designed to be placed on the sockets of rectangular connectors of the "D SUBMINIATURE" type.

Such a polarizing device consists of a plastic yoke having in section the shape of a U. This yoke is fixed to the socket by its central branch and each of the two other branches is formed of three sectionable strips. By cutting the strips associated with the fixed and mobile sockets in a complementary manner, we can match the sockets of each connector, eliminating the risk of connection errors.

 However, due to their design including sectionable lamellae, these detractors have the disadvantage that an error in the code is not recoverable and leads to their rejection. In addition, the number of possible codes is Limited and prohibits the use of these polarizers when a large number of identical connectors are installed on the same board.

 Furthermore, as illustrated by example in document FR-A-1 474 721, a number of rectangular multicontact electrical connectors are designed so that they include coding or coding pieces that can be indexed at will by the user. However, the coding pieces fitted to these connectors cannot be installed on connectors not provided for receiving them. In particular, they cannot be used on rectangular connectors of the "D SUBMINIATURE" type which equip a large part of aeronautical and computer equipment.

 The present invention specifically relates to a keying assembly for connecting without risk of reversal the two sockets of a multi-contact electrical connector and rectangular shape not equipped with keying, while having the same advantages as the coding pieces which equip existing polarized connectors (no risk of rejection of the polarized, high number of possible codes).

To this end, there is provided a keying assembly for a multi-contact electrical connector socket, this socket comprising a body provided with a protruding flange approximately in the shape of a rectangle, said assembly being characterized in that it comprises:
- a stirrup approximately in the shape of a rectangle, provided with an internal cutout capable of receiving the body of the socket and, on the short sides of the rectangle formed by the stirrup, of two protrusions pierced with a hole for fixing this stirrup to another identical stirrup ;;
- at least two coding keys each comprising a threaded shank capable of being received in aligned fixing holes formed in the edge of the socket and in the stirrup, near the short sides of the rectangles, a fixing nut being screwed onto the threaded tail of each key and the latter being immobilized in rotation in the stirrup by a stop means.

Thanks to these characteristics, the socket is fixed on
The stirrup by means of coding keys, the orientation of which is determined during this fixing. The two sockets constituting the connector are then connected and fixed to each other, preferably by captive screws, each of these screws having a threaded end adjacent to a central portion of diameter less than the internal diameter of the tapped holes constituting the fixing holes formed in the protuberances, and of length greater than the length of these holes.

 In order to allow a staggered mounting of the fixed sockets on the plate which supports them and thus to reduce the size of these sockets, the protuberances are preferably offset entirely from the same side, relative to the middle of the small sides of the rectangle .

 In order to facilitate mounting by allowing the coding keys to be kept in position on the bracket and on the socket, before their fixing on a plate or on a cable clamp, each of the coding keys can be maintained by a washer. stop received in a counterbore formed in the stirrup to a depth at least equal to the thickness of your stop round.

 When the body of the socket has a trapezoid section, a first coding can also be obtained by giving the internal cutout of the stirrup a trapezoidal shape identical to that of the body of the socket.

 In a preferred embodiment of the invention, each coding key comprises a coding head of square section and the stop means comprises a planar shoulder formed on the stirrup and on which abuts one face of the coding head. coding.

 Thirty-two different codes can in particular be obtained by using only two types of coding keys. The first type of key consists of keys whose coding head has at its end a notch formed parallel to one of the faces of the square on at least half of its section.

The second type of key consists of keys whose
The end of the coding head has a notch at 450 with respect to the faces of the square, over at least half of its section.

An exemplary embodiment of the invention will now be described, by way of non-limiting example, with reference to the accompanying drawings in which
- Figure 1 is an exploded perspective view showing the fixed socket and the mobile socket of a sub-miniature type D multi-contact electrical connector, each of these sockets being equipped with a keying assembly according to the invention;
- Figure 2 is a view of c8té, in partial section Le, showing the fixed and mobile sockets of the connector of Figure 1 each equipped with a keying assembly according to
The invention, before fixing these sockets;
- Figure 3 schematically illustrates the staggered layout of several fixed sockets equipped with assemblies according to the invention on the same support plate; and
- Figures 4a and 4b are perspective views showing on a larger scale two types of coding keys which can be used in accordance with the invention.

 In FIGS. 1 and 2, the references PF and PM respectively denote the fixed socket and the mobile socket of a multi-contact electrical connector of the "D SUBMINIATURE" type, defined by the MIL C.24308 standard. Such connectors, which are commonly used in the aeronautical and computer industries, are well known to specialists, so that a detailed description will not be made here.

For a good understanding of the invention, it will simply be recalled that each of the two sockets PF and PM comprises a body CF, CM provided with a planar projecting edge RF,
RM rectangular shape. In its part located immediately behind the RF rim, RM the body CF, CM of each of the sockets has a trapezoidal section. Near each of the short sides of the rectangle formed by the rim RF, RM, the latter is crossed in its center by a fixing hole TF, TM.

 Each of the fixed PF and mobile PM sockets of the connector shown in FIG. 1 is connected to a bundle of electrical cables FF and FM. The connection of the mobile outlet PM to the fixed outlet PF thus makes it possible to electrically connect each of the cables of the FM harness to a corresponding cable of the FF harness.

The fixed socket PF of the connector is designed to be mounted on a support plate PS for electrical connection, only part of which is shown in FIG. 1. For this purpose, the panel which constitutes the plate PS present, for each fixed socket PF, an opening OP whose shape and dimensions are approximately the same as those of the part of the body CF of trapezoidal section located behind the edge RF. When this part is received in the opening OP, holes TP formed in the panel are aligned with The holes
TF. Usually several fixed sockets identical to the socket
PF are grouped on the same PS electrical connection board.

By the way, the mobile outlet PM is designed to be fixed on a SC cable clamp partially surrounding the bundle of FM cables near this outlet. For this purpose, holes
TS formed in the cable clamp SC are aligned with the holes TM of the mobile socket when the cable clamp is in place.

 According to the invention, the connector which has just been described is associated with an assembly serving to fix the two plugs of the connector to each other while constituting a polarizing device eliminating any risk of involuntary permutation of two mobile plugs during the connection of these sockets to the fixed sockets carried by the PS board.

 For each of the fixed PF and mobile PM sockets of a given connector, this assembly includes a part 10, called a stirrup, which. generally has the shape of a rectangular frame. The stirrups 10 equipping the fixed PF and mobile PM sockets are identical. They can in particular be made of a molded or machined aluminum alloy, or of a molded thermo-plastic material fitted with inserts at the location of the fixing holes.

 Each of the stirrups 10 has an internal opening or cut 12, of trapezoidal shape, the shape and dimensions of which are identical to those of the parts of the bodies CF, CM of the sockets situated immediately behind the corresponding edges RF, RM.

The stirrups 10 are approximately rectangular in shape, their width being equal to that of the RF edges and
RM of sockets while their length is slightly greater than the length of these edges.

 Each of the stirrups 10 has a flat face 14 intended to be applied either against the plate PS or against the cable clamp SC. The opposite faces of the stirrups 10 also have a flat central part 16 extending over their entire width and over most of their length. This flat part 16 is parallel to the flat face 14 and its length is identical to that of the edges RF and RM of the sockets, so that these edges come to be applied on these flat parts of the stirrups 10 when the part of trapezoid section; dale of the body of the corresponding socket is placed in the opening 12 of the stirrup.

 On either side of this planar part 16, each of the stirrups 10 has two projecting parts 18, adjacent to the short sides of the rectangle formed by the bracket; Each projecting part 18 is connected to the flat part 16 by a shoulder 20 parallel to the short sides of the rectangle and perpendicular to this flat part. As will be seen later, this shoulder 20 makes it possible to immobilize the coding keys in rotation when these are fixed on the bracket 10.

 Each of the stirrups 10 further comprises, on the short sides of the rectangle and beyond the protruding parts 18, two protuberances 22 whose thickness is slightly greater than that of the protruding parts 18 and whose width is at most equal to half the width of the short sides of the rectangle.

 In order to allow a staggered arrangement of the stirrups 10 on the PS plate as illustrated in FIG. 3, the protrusions 22 of the same stirrup 10 are offset entirely on the same side relative to the middle of the short sides of the rectangle formed by this stirrup. A maximum number of fixed sockets can thus be installed on the same plate of given surface.

 To allow the coding keys and the PF, PM sockets to be fixed on each of the stirrups 10, the latter are crossed by two fixing holes 24 opening into the flat part 16, between the edges of the opening 12 and the shoulders 20, equidistant from the longest sides of the rectangle formed by the stirrup. Laminations 26 are formed on the plane face 14 of each of the stirrups 10 around the holes 24.

Finally, each of the protuberances 22 is crossed in its center by a tapped hole 28 whose axis is perpendicular to the flat face 14 and to the plane part 16. The holes 28 allow the bracket 10 carrying the mobile outlet PM to be fixed on
The stirrup 10 carrying the fixed socket PF.

 According to the invention, each of the stirrups 10 is associated with two coding keys 30 each composed of a threaded shank 32 and a coding head 34 of square section, in which a notch 36 is made allowing coding.

 The threaded shank 32 of each of the coding keys 30 freely crosses a fixing hole TF or TM formed in the rim of the corresponding socket, as well as a fixing hole 24 formed in the bracket 10. More precisely, when the rims PF and PM sockets are applied to the flat parts 16 of the stirrups 10 so that the trapezoidal section of the body of the socket is embedded in the opening 12 of the stirrup, the TF, TM fixing holes formed in the sockets are aligned with the holes 24 shapes in the stirrups. The threaded shanks 32 of the coding keys are then placed in these aligned holes, so that the coding head 34 of each key is located on the side of the corresponding socket.

One of the edges of the head 34 of each coding key is then in abutment against the corresponding shoulder 20. In this way, the coding key 30 is immobilized in rotation in a well-determined position of its head 34.

 To keep each coding key 30 in the position corresponding to the desired coding, a stop washer 38 is fitted on the part of the threaded tail 32 projecting beyond the flat face 14 of the stirrup 10. This stop washer 38 has a thickness less than the depth of the counterbore 26, so that it is housed entirely in the latter and does not lead to any increase in the thickness of the assembly.

 To fix the PS fixed socket PF associated with a bracket 10 by two coding keys 30 held in place with the locking washers 38, engaging the parts of the threaded shanks 32 projecting beyond the flat face 14 of the stirrup 10 in the holes TP formed for this purpose in the plate, then nuts 40 are screwed onto these threaded shanks.

Comparably, for fixing the cable clamp
SC on the mobile outlet PM, associated with another bracket 10 by two coding keys 30 held in place by the locking washers 38, the parts of the threaded shanks 32 protruding beyond the flat surface 14 of L ' bracket in the holes TS formed for this purpose in the cable clamp and we screw on the ends of the tails 32 of the nuts 40.

 The coding keys 30 associated respectively with the fixed socket PF and with the mobile socket PM of the same connector are identical, and their orientations defined by the shoulders 20 are opposite so that these two sockets can freely emboss the one in the other but that the connection of the mobile outlet PM to another fixed outlet PF is impossible.

 To complete the preparation of the plugs before their connection and as illustrated in FIG. 2, captive screws 42 are placed in the two tapped holes 28 of the bracket 10 associated with the mobile plug PM. Each of these screws 42 comprises a head 44, a threaded end 46 and a cylindrical central part of small diameter 48. The threaded part 46 can be screwed into the tapped holes 28 while the central part 48 has a diameter less than the smallest diameter of the tapped holes 28 and a length at less equal to the length of these tapped holes.

 In this way, the screws 42 are screwed into the tapped holes 28 of the bracket 10 associated with the mobile outlet PM, until the central parts of small diameter 48 of the screws are located entirely in the tapped holes 28 Accidental escape of the screws 42 is then impossible.

 When the mobile outlet PM is connected to the fixed outlet PF which corresponds to it, the heads 34 of the coding keys 30 associated respectively with the fixed outlet and the mobile outlet fit into one another and the fixing of the mobile socket on the fixed socket is ensured using screws 42, the threaded ends of which 46 are screwed into the tapped holes 28 of the bracket 10 associated with the fixed socket PF. A counterbore 50 formed at the end of each of the threaded holes 28 opposite the flat face 14 of the stirrup makes it possible to start the embedding of the sockets before screwing the screws 42, receiving the threaded ends 46 of the latter. In addition, a lock washer 52 is placed between the head 44 of each of the screws and the caliper 10, to avoid accidental loosening of the screws.

 Thanks to the assembly according to the invention, if an attempt is made to connect the mobile socket PM of another connector to the fixed socket PF, the heads of the coding keys 30 do not fit together but instead come into abutment against others.

The length of the heads of the coding keys being determined in such a way that the electrical contacts of the fixed sockets cannot touch each other when these two sockets do not belong to the same connector, no electrical contact is then established and any risk of damage a circuit due to a bad connection is therefore deleted.

 As mentioned previously, the coding of the various connectors is ensured by notches 36 formed in the heads 34 of square section of the coding keys 30.

 Preferably and as illustrated in FIGS. 4a and 4b, coding keys 30 of two different types are used.

To facilitate reading, the references of the coding key of
FIG. 4a has been assigned the index a and the references of the coding key of FIG. 4b have the index b.

 In FIG. 4a, the head 34a of the coding key 30a has at its end and over at least half of its section a notch 36a formed parallel to one of the faces of the square defined in section by the head of the key. When the positioning of the key 30a is such that the notch 36a is turned upwards as illustrated in FIG. 4a, only an identical coding key 30a but in which the notch formed in the head 34a is turned downwards can be embossed on the coding key 30a, as shown in dashed lines.

 Since each of the coding keys can have four different orientations with respect to the stirrup and the socket associated therewith and since each socket includes two coding keys, sixteen different codes can be obtained with identical conforming coding keys à The description which has just been made with reference to FIG. 4a.

 In FIG. 4b, the end of the head 34b of each of the coding keys 30b has at its end and over at least half of its section a notch 36b formed approximately along a diagonal of the square formed in section by the head of the key, or 450 with respect to the faces of this square. As in the embodiment of FIG. 4a, only an identical coding key and the head of which is oriented in a complementary manner can be embossed on the head of the key 30b, as shown in dashed lines. As in the case of FIG. 4a, sixteen different codes can also be obtained by using coding keys identical to the key 30b.

 Thus, by using two types of coding keys such as those which have just been described with reference to FIGS. 4a and 4b, thirty two different codings can be carried out. In this way, any involuntary permutation of the mobile sockets of two connectors is impossible as long as the number of fixed sockets carried by the same electrical connection plate does not exceed thirty two, which is almost always the case.

 The keying assembly according to the invention has the particular advantage of being able to be used with existing multi-contact rectangular connectors without any keying, without requiring a large number of parts since the stirrups 22 are all identical and the number of keys coding is maximum of two. In addition, it makes it possible to correct without damage any coding error, since the orientation of the coding keys can possibly be modified by releasing the head of the key from the shoulder 20 formed on the projecting part of the bracket. Finally, it makes it possible to obtain a number of important codes, practically unlimited if one accepts to multiply the number of types of coding keys used.

Claims (9)

 1. Coding assembly for a socket (PF, PM) of a multi-contact electrical connector, this socket comprising a body (CF, CM) provided with a flange (RF, RM) projecting approximately in the shape of a rectangle, said assembly being characterized by the fact that he understands  - a stirrup (10) approximately in the shape of a rectangle, provided with an internal cutout (12) capable of receiving the body of the socket and, on the short sides of the rectangle formed by the stirrup, of two protuberances (22) pierced a fixing hole (28) of this stirrup to another identical stirrup ;;  - at least two coding keys (30) each comprising a threaded tail (32) capable of being received in aligned fixing holes (TF, TM, 24) formed in the edge of the socket and in the stirrup, close short sides of the rectangles, a fixing nut (40) being screwed on the threaded tail of each key and the latter being immobilized in rotation in the stirrup by a stop means (20).  2. Assembly according to claim 1, characterized in that the fixing holes formed in the protuberances (22) are tapped holes (28).  3. The assembly of claim 2, for a mobile outlet (PM), characterized in that it further comprises captive screws (42) each having a threaded end (46) adjacent to a portion (48) of smaller diameter the inside diameter of the tapped holes (28) and of length greater than the length of these holes.  4. An assembly according to any one of claims I 3, characterized in that the protuberances <22) are offset entirely on the same side relative to the middle of the short sides of the rectangle.  5. An assembly according to any one of claims 1 to 4, characterized in that each of the coding keys <30) is held on the stirrup by a locking washer (38) received in a countersink (26) formed in the bracket (10) to a depth at least equal to the thickness of the locking washer.  6. An assembly according to any one of claims 1 to 5, for a socket (PF, PM) whose body has a trapezoidal section, characterized by the fact that the internal cutout <12) of the stirrup (1C) has a trapezoidal shape, identical to that of the connector body.  7. Assembly according to any one of claims I to 6, characterized in that each coding key (30) comprises a coding head (34) of square section, the stop means comprising a flat shoulder (20) formed on the stirrup (10) and on which abuts a face of the coding head.  8. An assembly according to claim 7, characterized in that the end of the coding head (34a) has a notch (36a) formed parallel to one of the faces of the square, on at least half of its section.  9. An assembly according to claim 7, characterized in that the end of the coding head (34b) has a notch (36b) at 450 relative to the faces of the square, on at least half of its section.