EP1489700B1

EP1489700B1 - Safety connector arrangement

Info

Publication number: EP1489700B1
Application number: EP04425430.8A
Authority: EP
Inventors: Andrea Nisi; Claudio Priori; Marco Piromalli
Original assignee: Link Srl
Current assignee: Link Srl
Priority date: 2003-06-20
Filing date: 2004-06-11
Publication date: 2013-09-04
Anticipated expiration: 2024-06-11
Also published as: ITRM20030306A0; ITRM20030306A1; EP1489700A1

Description

The present invention relates to a male-female electrical connector device provided with security device.
More specifically, the male-female electrical connector device provided with security device according to the invention as claimed is suitable to reduce the possibility of unintentional intrusion within the same electric contact, but the introduction of the male electrical contact, thanks to the use of an innovative safety device and to the use of a corresponding female electrical contact.
Male-female kind electric connector devices are universally known, such as the connector device comprised of the jack for numerous acoustic apparatuses, or those used to load numerous electronic devices, such as the cellular phone.
Male electric contact is usually comprised of a cylinder, or of a cylindrical crown, covered outside by metallic material.
Female contact is a hollow cylinder having dimensions corresponding to those of the male contact, and provided inside with a conductive surface, suitable to contact the corresponding surface of the male contact as soon as the latter is properly introduced within the same female contact.
However, for some electrical connector devices, these kind of connector devices, even working properly, are very dangerous.
In fact, in case of high power electrical connector devices, is there a serious risk of unintentionally touching the inner conductive surface of the female contact, e.g. by the tip of a screwdriver.
To overcome this drawback, different female contacts provided with safety devices have been proposed.
For example, the device described in the US patent n° 5,921,823 comprises a piston pushed by a spring inside the female contact.
In this way, when the male contact is not inserted as yet, cavity of the female contact would be protected by the piston. Unintentional contact with a conductive tip would be consequently less probable.
However, it is to be noted that this solution according to the US patent n° 5,921,823 is not particularly efficient.
In fact, as to the inventiveness, spring systems (or similar elastic means) for electrical connector devices were already known before the filing date of the above patent.
For example, we can mention the US patent n° 4,652,067 , describing an electrical connector device the female contact of which comprises a piston pushed by a spring. Said piston projects within the spring and contacts an inner conductive surface once the male contact is inserted.
US patent n° 5,175,493 further describes a piston device released by a spring to make current tests for single elements of a circuit.
US patent n° 5,118,301 describes a device similar to the one according to US patent n° 4,652,067 , with a piston pushed by a spring, said spring, once pushed from outside, contacts a conductive surface within the female contact.
One skilled in the art, being aware of the male-female contacts similar to the jack type, and knowing the last three US patents, would have surely conformed the existing solutions to put the conductive surface within the female contact on the inner wall of a hollow cylinder and at the same time would have had used a piston for safety reasons, as in the first mentioned US patent n°5,921,823 .
It is well clear that this last patent claims also particular arrangements, providing corresponding more or less innovative solutions.
Furthermore, and in any case, the solution of this patent is not so efficient as it would seem.
In fact, if on one side the inlet of the female contact is protected by the piston, on the other side it is not possible to use too stiff or too pre-loaded springs, otherwise it would be difficult the introduction of the male contact.
Not being possible loading too much the springs, an unintentional movement of a conductive tip could in any case pushing the piston, contacting the inner surface of the female contact, with high risks for the device connected with the tip or, even worse, for the operator.
Still, the Italian Patent Application n° RM99A000137 ( ITRM990137 A1 ) discloses a female contact provided with a safety device able to prevent unintentional introductions, but it provides that it is necessary to unlock the safety device pushing some buttons projecting out of the connector device. Said buttons are automatically pushed by the insulating female housing of the male contact. It is in any case necessary providing said buttons on the outer wall of the female contact, this requiring a particular working.
Always exploiting the principle of the piston and spring arrangement, even if in a very specific way for a particular application, device disclosed in US patent n° 6,275,054 allows a contact between at least a pair of male-female contacts.
It is object of the present invention that of providing a male-female electrical connector device, wherein the female contact is provided with a safety device and is suitable to receive and electrically connect a male contact, solving the drawbacks and overcoming the limitations mentioned in the above.
It is object of the present invention a safety electrical connector device as defined in claim 1.
Preferably, according to the invention, said shoulders are cavities realised in the wall and the side of which faced toward the bottom of the cavity is oblique toward said bottom, i.e. the angle between the vertical profile of the wall and said oblique side is an obtuse angle.
According to the invention, the wall just under said oblique side can preferably be, at least for a part of it, thinner than the wall just above said cavity, the profile of the side of the wall outward most with respect to the cavity not being modified.
Preferably, according to the invention, said obtuse angle is between 110° and 160° sexagesimal, still more preferably between 125° and 145° sexagesimal.
Preferably, according to the invention, said lower ends of the first protection have the side faced toward inside, opposite to the side faced toward the wall and parallel to the same, oblique, in such a way that the thickness of the lower ends reduces close to the bottom of the cavity.
Preferably, according to the invention, the second protection is provided with an upper end so shaped to partially penetrate within said opening of the upper base of the first protection.
Preferably, according to the invention, check elastic means are comprised of an arc spring, the arc being opened toward the cavity bottom, or of two elements joined by a spring, or of one or more lugs, laterally joined with the second protection and provided with elastic means, tending to open the same, said lugs realising, when their ends are engaged with said shoulders, in the direction of the inner part of the cavity, an acute angle with respect to the lateral profile of the second protection.
According to the invention, it is preferable that the electric contact comprises buckling elastic means of the safety device, always pushing said safety device toward the inlet of the female electrical contact.
Preferably, according to the invention, said buckling elastic means comprise first and second buckling means, said first buckling elastic means acting on the first protection, said second buckling means acting on the second protection.
Preferably, according to the invention, said buckling elastic means comprise helicoidal springs.
According to the invention, the above electric connector device preferably comprises a first stop shoulder element, integrally joined with the second protection, to make contact, at the end of stroke of the safety device within the female contact, with a corresponding second stop shoulder element joined with the bottom of said cavity.
According to the invention, male contact and female contact can be each one provided with an insulating female casing and with an insulating male casing, said insulating casings being provided with coupling and locking means, and coupling and locking involving the introduction of the male electrical contact within the female electrical contact.
The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein:

Figure 1a is a longitudinal section of a female contact according to the invention, in the inactive configuration;
Figure 1b is a perspective, section view of the first protection of the safety device according to the invention according to figure 1a, projecting outside the female contact;
Figure 1c shows two different sections and perspectives of the second protection of the safety device according to invention;
Figure 1d shows an enlargement of a part of the female contact of figure 1a;
Figure 2 is a longitudinal section of the configuration of the female contact of figure 1 a when the male contact pushes the first protection for a part of its stroke, so as to release the second protection;
Figure 3 is a longitudinal section of the piston stop and of the two protections, corresponding to the electric contact position between a male contact (not shown) and the female contact of figures 1 and 2;
Figure 4 shows a different embodiment of the electrical contact and of the safety device according to the invention; and
Figure 5 shows a further different embodiment of the electrical contact and of the safety device according to the invention.

In the figures, the same reference numbers will be used for the same elements.
Making reference to figures 1 a and 1 d, the female contact 100 is provided with a male insulating envelope 3, 11, and an inner wall 12, said wall 12 being at least partially conductive. Female electrical contact 100 is provided with a safety device essentially comprised of a first protection 1 and a second protection 2, check elastic means 4 (arc or "Ω" spring) and two helicoidal springs 8 and 9.
The first protection 1 can be observed in a perspective view in figure 1b. it is comprised of a hollow cylinder, a fascia of its lower part, provided inside the female contact in the rest position shown in figure 1a, has a progressively reduced thickness until its truncated lower end, so as its section is trapezoidal, as it can be observed in figure 1b (part 1'). It provides notches 1" to let the ends 4' of the check elastic means passing, as it will described in the following.
It is also possible that the protection 1 is not completely solid.
The second protection 2 is of the "cylindrical type". For example, in figure 1a it is comprised of two cylinders and of a conical tip 2'. Tip 2' partially projects with respect to the upper base of the cavity 14 of the contact 100.
In figure 1c it is shown a preferred embodiment of the second protection, with the curved housing 2" to introduce the check means 4. It must be noted that a second part of the second protection (not shown) can be restrained in such a way to limit the movement of the check means 4, or even to block the same.
The second protection 2 is lower than the upper base of the first protection 1.
Check means 4, that in the figure are comprised of the inverted "U" (or "Ω") spring, prevent the advancement of the second protection 2.
Really, spring can be integral with the second protection 2, for example obtained by a single die and comprised of plastic material.
Ends 4' of the spring engage with the two shoulders 5 of the wall 12, e.g. notches. Said wall 12 has a different thickness between the upper part and the lower part (lower than the spring in the rest position of the safety device).
More specifically, in the example shown, a part of the end 4' engages with notches 5 and another part of the ends engages with the tip 1' of the first protection 1.
In this way, when the first protection 1 is pushed downward by the male contact, tips 1' push the check means 4, said check means contracting horizontally up to sliding along the oblique side of the trapezoidal section tips 1', as shown in figure 2.
Now, prosecuting the pushing action on the first protection 1 and on the conical tip 2' of the second protection 2, check means 4 and the safety device is moved downward, buckling the elastic force of the two springs 8 and 9.
In any case, check elastic means 4 are provided with a "cylindrical" element 6, having base 7 lower than the same check means contacting a corresponding cylindrical element 10 raising on the base 13 of the cavity 14 of the female contact, thus realising the stop of the safety device, in the position of figure 3. It is clear that the dimensions of the parts can be chosen so as the base 7 directly contacts the bottom 13 of the cavity 14, thus eliminating the need of the presence of the cylindrical element 10.
Cylindrical element 6 is preferably integral with the second protection 2.
In correspondence of the stop position of the element 6 against the element 10, it is obtained the complete activation of the locking device of the male contact within the female contact.
This locking can occur thanks to coupling and locking means provided on the same electrical contacts, but it is more convenient coating the same before the coupling and thus using the insulating envelopes provided with similar coupling and locking means.
Advantageously, it is possible to use a female insulating element for the male contact and a male insulating envelope for the female contact, as those disclosed in US patent 5,685,730 .
Said coupling and locking means also allow the releasing of the elements.
It is to be noted that according to the present invention as claimed it is possible to provide solutions for the check means 4 different with respect to the arc spring.
As it appears from figure 4, said check elastic means 4 are comprised of two elements 15, joined horizontally by a spring 16. Ends of said means are engaged with the same shoulders 5 when the safety device is in the rest position and are disengaged by the first protection in the same way of the arc spring, when the male electric contact 300 is introduced within the female contact.
As further example, the second protection 2 of figure 5 is laterally provided with said check elastic means, being the latter comprised of two lugs 17, for example returned by a spring (not shown). In this case too, the ends of the two lugs are engaged in said shoulders 5 and are disengaged from the first protection 1. Buckling elastic means 23 (e.g. springs) are laterally provided between the first 1 and the second 2 protection.
In all the previous embodiments, in the female contact there are distingushed the part 100, with the cavity 14, from the part 200, containing a further cavity 20, within which the electrical wires are inserted and fixed by suitable fixing means, even through the openings 21.
In this way, the above different embodiments are interchangeable with respect to the same part 200.
Thanks to the safety device according to the present invention, particularly suitable for high power electrical contacts, it is reduced the risk of unintentional introduction of conductive materials within the female contact.
In fact, pressure surface useful to release the safety device according to the present invention as claimed is minimum, it substantially being the section of a hollow cylinder. However, the pressure surface can be further reduced to one or two very small areas, providing the hollow cylinder with two linear projections.
The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.

Claims

Safety electrical connector device, comprising a male electrical connector (300) and a female electrical connector (100) both having a longitudinal extension axis and being coaxial with respect to said longitudinal extension axis, wherein
- the female electrical connector being provided with a cavity (14) having a cavity opening and a cavity closed end (13) opposite to the opening along said longitudinal extension axis,

- said cavity (14) being delimited laterally with respect to said longitudinal extension axis by an at least partly electrically conductive wall (12),

- the female electrical connector being further provided with a coaxial safety device,
said safety electrical connector device being characterised in that the coaxial safety device comprises:

- a first protection (1) extended along said longitudinal extension axis and having first end towards said cavity opening and second end towards said cavity closed end (13), the first and second ends being open, and

- a second protection (2) extended along said longitudinal extension axis and provided inside the first protection (1),
said safety device further comprising check elastic means (4), diametrically occupying all the cavity (14), and fixed to said second protection (2), said elastic means being provided with ends (4') that are, in a rest position, partially engaged with shoulders (5) realised on the inner side of the wall (12) and partially contacting said second end (1') of the first protection (1), the check elastic means (4) exerting an elastic force against the wall (12) in correspondence of said shoulders (5), so that, when the first protection (1) is pushed inward the cavity (14) along said longitudinal extension axis by the male electrical connector, check elastic means (4) engage with said second end (1') and are consequently disengaged from said shoulders (5), and the safety device is integrally moved toward said cavity closed end (13).
Safety electrical connector device according to claim 1, characterised in that it comprises buckling elastic means (8, 9) for the safety device, pushing said safety device always toward said cavity opening of the female electrical connector (100).
Safety electrical connector device according to claim 2, characterised in that said buckling elastic means (8, 9) comprise a first and a second buckling elastic means, said first buckling elastic means (8) acting on the first protection (1), said second buckling elastic means (9) acting on the second protection (2).
Safety electrical connector device according to claim 2 or 3, characterised in that said buckling elastic means (8, 9) comprise helicoidal springs.
Safety electrical connector device according to any of claims 1 to 4, characterised in that said shoulders (5) are cavities realised in the wall (12) and have a last portion (5') toward said cavity closed end (13) that presents an obtuse angle with respect to the profile of the wall (12) parallel to said longitudinal extension axis.
Safety electrical connector device according to claim 5, characterised in that the wall (12) just after said last portion (5') toward said cavity closed end (13) is , at least partially, thinner than the wall (12) just before said last portion (5').
Safety electrical connector device according to claim 5 or 6, characterised in that said obtuse angle is between 110° and 160° sexagesimal.
Safety electrical connector device according to claim 6, characterised in that said obtuse angle is between 125° and 145° sexagesimal.
Safety electrical connector device according to any of claims 1 to 8, characterised in that said second end (1') of the first protection (1) is wedge-shaped, in such a way that the thickness of the lower ends (1') reduces towards said cavity closed end (13).
Safety electrical connector device according to claim 1, characterised in that the second protection (2) is provided with a first end (2') towards said cavity opening that is so shaped to partially penetrate within said first end of the first protection (1), when the male electrical connector is not inserted in the female electrical connector.
Safety electrical connector device according to any of claims 1 to 10, characterised in that said check elastic means (4) are comprised of an arc spring, the arc being opened toward the cavity closed end (13).
Safety electrical connector device according to any of claims 1 to 10, characterised in that said check elastic means (4) are comprised of two elements (15) joined by a spring (16).
Safety electrical connector device according to any of claims 1 to 10, characterised in that said check elastic means (4) are comprised of one or more lugs (17), laterally joined with the second protection (2) and provided with elastic means, tending to open the same with respect to the second protection (2), said lugs (17) realising, when their ends are engaged with said shoulders (5), towards said cavity closed end (13), an acute angle with respect to said longitudinal extension axis.
Safety electrical connector device according to any of claims 1 to 13, characterised in that it comprises a first stop shoulder element (6), integrally joined with the second protection, to make contact, at the end of stroke of the safety device within the female connector (100), with a corresponding second stop shoulder element (10) joined with the bottom (13) of said cavity (14) at said cavity closed end (13).
Safety electrical connector device according to any of the preceding claims, characterised in that the male electrical connector and the female electrical connector are respectively provided with an insulating female casing and with an insulating male casing, said insulating casings being provided with coupling and locking means, and coupling and locking involving the introduction of the male electrical connector within the female electrical connector.