EP0353539A1

EP0353539A1 - Connector with free plug and socket for electric cables

Info

Publication number: EP0353539A1
Application number: EP89113137A
Authority: EP
Inventors: Andrea Percio; Giovanni Zago
Original assignee: ILME SpA; Industria Lombarda Materiale Elettrico ILME SpA
Current assignee: ILME SpA; Industria Lombarda Materiale Elettrico ILME SpA
Priority date: 1988-07-29
Filing date: 1989-07-18
Publication date: 1990-02-07
Anticipated expiration: 2009-07-18
Also published as: DE68904375D1; IT8821590A0; ATE84643T1; IT1227022B; ES2037345T3; EP0353539B1; DE68904375T2

Abstract

The proposed electrical connector is provided with a terminal board (21) and a clamping device (1, 3) which is integral with said terminal board (21) during use. These consist of two separate elements, each having a reciprocal engaging means.

This can comprise, as regards the clamping device, a pair of arms (9, 10) integral with said device and having shaped ends.

In particular the arms (9, 10) can be integral with just one (3) of the two coupling brackets (1, 3) suitable for receiving the electric cable between them.

Preferably, at least one of the two arms has an enlarged head (12) at its free end, capable of locking in an axial direction into a hole (25) provided on the terminal board (21).

The other arm (10) can also be equipped with a seat (13) capable of being received into a peripheral slot (27) provided on the terminal board (21), provision being made in this case for the rotation of the engaging means of the other arm (9) with respect to the terminal board (21).

Description

The present invention relates to the free connectors equipped with cable clamping devices which are normally used as free sockets and plugs. The aim of the cable clamping devices is to clamp the cable to the plug or socket, preventing it from being unintentionally extracted owing to traction being exercised on it, either as the result of a mistake in operation or in the case of an accident.
The cable clamping devices prevent the connecting terminals from being subjected to traction and prevent the cable itself from being disconnected from the terminal board, thereby causing serious trouble.
Cable clamping devices made of plastic material are well-known where two tongues of the same material extend from the periphery of the terminal board and, at the opposite end with respect to the terminal board, broaden into two coupling brackets, inside which the electric cable is inserted. After the cable is inserted, the clamps are locked one against the other by means of a pair of screws, with their respective nuts, thus carrying out fixing of the cable inserted between them.
The device described has some disadvantages, such as:

a) wiring is difficult, since the space on the terminal board where the cable must be inserted and clamped is partly occupied by the cable clamping device;
b) costs are relatively high;
c) it is impossible to use the same terminal boards which are used for the corresponding fixed plugs and sockets if the cable clamping device is in one piece with the terminal board.

Aim of the present invention, therefore, is to produce a clamping device for free sockets and plugs which is able to avoid the difficulties mentioned above, that is one which facilitates cable connections, allows an identical terminal board to be contructed for fixed and free sockets and plugs, and facilitates installation.
This aim has been achieved by providing an electrical connector equipped with a terminal board and a clamping device which are integral with said terminal board during use, in which said clamping device and said terminal board consist of two separate elements, each equipped with a reciprocal engaging means.
Said engaging means can consist, as regards the clamping device, of a pair of arms integral with said device.
In particular, the arms can be integral with just one of the two coupling brackets suitable for receiving the electric cable between them.
Preferably at least one of the two arms has an enlarged head at its free end, capable of locking into a hole provided on the terminal board.
One arm can also be equipped with a seat capable of being received into a peripheral slot provided on the terminal board, provision being made in this case for the rotation of the engaging means of the other arm with respect to the terminal board. In this case the seat ends in a collar which prevents the arm from escaping.
The clamping of the cable into the clamping device is performed preferably by inserting the jagged wings of one bracket inside the corresponding openings, one wall of which is defined by a tongue suitable of cooperating with said jagged wings. The connection is detachable by operating upon resilient wings which allow said tongue to disengage from the jagged wings.
Preferably the two brackets are joined together during moulding by a metal strip.
The present invention will now be described more clearly in the following description of a preferred embodiment which is illustrated in the enclosed drawings, where:

Figure 1 shows a side view of the cable clamping device;
Figure 1a shows a section of one of the brackets making part of the clamping device, taken along the line a-a in fig. 1;
Figure 2 shows a top view of the terminal board being part of the connector device;
Figure 3 shows an enlarged partial section view of the terminal board, taken along the line 3-3 in figure 2;
Figure 4 shows a schematic perspective view of a connector with the cable assembled.

Referring now to figure 1, it can be seen how the clamping device comprises a clamping bracket 3 and a bracket 1 equipped with two equal symmetrical wings 2a and 2b. The two brackets 1 and 3 are joined together by means of a narrow strip 4. The wings 2a and 2b of the bracket 1 are jagged on their inner side.
The bracket 3 consists of a central part 5 suitable for receiving the cable, and of two equal openings 6a and 6b, inside which two elastic tongues 7a and 7b are provided, which are equal and symmetrical and suitable for engaging with the jagging teeth of the wings 2a and 2b. As can be noted in fig. 1a too, the tongues 7a and 7b are each provided with a wing 7c and 7d, respectively, which is resilient and projects in a perpendicular direction with respect to the tongues 7a and 7b themselves. The central part 5 of the bracket 3 in which the electric cable is housed is equipped with four projecting elements 8a, 8b 8c and 8d, having a conical shape with a rounded top, to ensure a better grip on the cable.
Referring again to figure 1, it will be noted how two arms, 9 and 10 respectively, leave from the bracket 3, being substantially perpendicular to the latter. The arm 9 ends in a head 12 above which an abutment 12a is provided. The arm is also equipped with a collar 11 for acting as a further ledge which can serve as a stop during wiring. The arm 10 ends in a seat 13 comprised between two collars, one of them, 14, located at the end and the other, 13a, more internally.
Referring now to figure 2, the terminal board 21, to which the free socket, plug or such is connected, is equipped, as is already known, with holes 24a, 24b, and 24c respectively, into which the wires will be inserted to carry out the connection. The terminal board is further equipped with fixing holes 22a and 22b and possibly with a notch 23.
The terminal board 21 is equipped with a further through hole 25, along its periphery. This hole is internally provided with four equal projections 26a, 26b, 26c and 26d, which extend downwards. The configuration of the walls of the hole 25 can be better seen in figure 3, where two of the projections, in particular 26c and 26d, are to be seen.
Lastly, there is a slot 27 cut out on the periphery of the terminal board 21, which is inserted obliquely into said terminal board 21 and is rounded at its end in a semicircle. This is located at a distance which corresponds to the distance between the two arms 9 and 10. In addition the slope of the slot 27 corresponds to the tangent of the circle which has the hole 25 at its centre.
Now the connection of the cable clamping device to the terminal board 21 will be described: the arm 9 (see figure 1) of the device is brought over the hole 25; the pin 11 with its hemispherical head 12 is then inserted into the hole 25. The heads 12 slides within the projections 26a, 26b, 26c and 26d, and finally protrudes from the hole 25. In this way, the projections 26a, 26b, 26c and 26d rest on the lower base of the head 12, where the diameter of the pin 11 is narrower and prevents the arm 9 from being extracted from the terminal board 21.
The other arm 10 of the bracket 3 is made to rotate around the pin 13 and positioned in correspondence with the slot 27. Then the arm 10 is pressed into the slot 27, slides along it and comes to abut against the semicircular rounded form at the terminal end of the slot.
In this way the bracket 3 is near to the cable which, in order to be clamped, has only to be gripped by the other bracket 1 whose wings 2a, 2b, are made to penetrate the openings 6a and 6b.
If it is desired to disconnect bracket 1 from bracket 3, in order to release the cable, it is sufficient to slightly push on the wings 7c and 7d, by hand or by means of a tool, bringing said wings nearer to each other. In this way, the tongues 7a and 7b disengage from the jagging teeth of the wings 2a and 2b, which can be withdrawn from openings 6a and 6b.
In this way a connector device with free plug has been produced which is capable of avoiding the drawbacks previously mentioned, in fact:

a) wiring is much simpler and quicker, in that the holes 24a, 24b and 24c are not hindered in any way during the said operation;
b) by constructing the device in two pieces, the parts obtained are much simpler and easier to manufacture; what is more, they can be supplied separately;
c) the terminal board produced for the device being the object of the invention can also be used for fixed plugs; by standardizing this component in such a way, an appreciable economic advantage is achieved.

Claims

1. A connector for free plugs and sockets, equipped with a terminal board (21) and a clamping device (1, 3) which is integral with the said terminal board (21) during use, characterized in that said clamping device (1, 3) and said terminal board (21) consist of two separate elements, each one having a reciprocal engaging means, said reciprocal engaging means comprising a pair of arms (9, 10) integral with said clamping device (1, 3) and having shaped ends, at least one arm (9) being equipped with an enlarged head (12) at its free end, capable of being locked into a hole (25) provided on the terminal board (21), said arms (9, 10) being both integral with only one (3) of the two coupling brackets (1, 3) forming the clamping device.

2. A connector according to claim 1 characterized in that it is provided with a second engaging means consisting of an arm (10) having a seat (13) at its free end capable of being received into a peripheral slot (27) provided on the terminal board (21), and externally confined by a stop collar (14), provision being made for the rotation of the other engaging means (12) with respect to the terminal board (21).

3. A connector according to claim 1 or 2, characterized in that the clamping device comprises two brackets (1, 3) one of which is equipped with jagged wings (2a, 2b) and the other with corresponding openings (6a, 6b), one wall of which is defined by a tongue (7a, 7b) suitable for cooperating with said jagged wings (2a, 2b), said tongue (7a, 7b) being provided with a resilient wing (7c, 7d), capable of allowing the tongue (7a, 7b) to be disengaged from the jagging teeth of the wings (2a, 2b).

4. A connector according to anyone of the preceding claims characterized in that the clamping device consists of two brackets (1, 3) joined to each other during moulding by a metal strip (4).