EP2040342A2

EP2040342A2 - Plug connector

Info

Publication number: EP2040342A2
Application number: EP20080105355
Authority: EP
Inventors: Orio Grandi
Original assignee: Fanton SpA
Current assignee: Fanton SpA
Priority date: 2007-09-20
Filing date: 2008-09-16
Publication date: 2009-03-25
Also published as: ITPD20070301A1; EP2040342A9

Abstract

The invention is a new connector (CV) for outlets and plugs comprising a main body (CP) with a compartment for the electric cable (CE), a locking element (SB) with a part (ASB) threaded on the outside (FSB) and teeth (DSB), a ring nut (C) that can be rotated in relation to said main body (CP), provided with an internal thread (FC) coupled with said external thread (FSB) of said locking element (SB), and wherein, on rotation of said ring nut (C), said locking element translates axially in relation to said ring nut (C) and said main body (CP), so that said teeth (DSB) of said locking element (SB), resting on sliding guides (GCP), converge towards the electric cable duct. The new connector comprises also a device (VB) for locking the rotation of the ring nut (C).

Description

The present patent relates to the sector of electrical systems for civil and industrial use and in particular it concerns a new plug connector.
At present two types of electrical connectors are substantially available on the market: electrical outlet and electrical plug; for safety reasons, the latter is provided with male contacts, while the former is provided with female contacts, so that, being constantly live, they are not external to the body of the outlet.
Said connectors can be fixed to the wall or fixed directly to the electric cable, which means that they are not fixed to any other surface, and in this case they are called plug connectors.
Plug connectors are known, which are constituted by a main body provided with a system for locking the electric cable, and by an outlet or plug element. The main body, which serves also as an insulating element, is made using resins with suitable dielectric strength, which furthermore feature good resistance to heat and impacts and good self-extinguishing properties. Said main body is substantially cylindrical in shape and is provided with an axial hole, in order to allow the passage of the electric cable, and with a seat for the insertion of the outlet or plug element at the bottom.
Said outlet or plug element is fixed to the main body, in such a way as to facilitate the assembly of plug and cable.
There are several systems for locking the cable; the most used, which is obviously the simplest one, is the locking system with clamps, wherein said clamps consist of one or more substantially linear elements, of the bridge type, provided at their ends with holes into which screws are inserted to lock the electric cable by pressure.
Although the cable locking system with clamps is quite widespread, it poses the drawback of being a bit complicated, in fact in order to install or remove the electric cable it is necessary to tighten or loosen the fixing screws of the wires and also those of the clamps, thus wasting a lot of time.
A screw-in system for locking the electric cable is known, consisting of a ring nut that substantially has the shape of a truncated cone, with an axial hole and an internal thread; said ring nut is screwed onto the upper cut part of the main body, and provided with an external thread near the upper part. The locking of the cable is ensured by pressure, when said ring nut is screwed onto said main body, tightening the cut ends of the main body.
One of the main drawbacks posed by the known screw-in systems for locking cables is due to the fact that the thread is exposed to weather agents or to the dirt of the external environment, with consequent negative effects.
A further drawback is due to the fact that the ring nut may become loose over time and leave the contacts of the electric cable exposed, with consequent safety problems.
Furthermore, the length of the plug connector varies, in fact when the cable is not inserted therein the connector is longer than when the ring nut is screwed to lock the electric cable.
Another problem posed by the known screw-in systems for locking electric cables is due to the fact that said ring nut is separated from the main body, and therefore there is the risk of losing it.
To remedy all the above drawbacks a new type of electric plug connector has been designed and constructed.
The new plug connector comprises, in its main parts, a substantially cylindrical main body, provided with an axial compartment for the passage of the electric cable and, at the top, one or more guides, an outlet or plug element applied to the lower part of said main body, a cable locking element and a ring nut, with internal thread, positioned at the level of the upper part of said main body, and a device for locking said ring nut.
Said main body serves also as an insulating element and is made using resins with suitable dielectric strength, which furthermore feature good resistance to heat and impacts and good self-extinguishing properties.
The locking of the electric cable is ensured by the presence of said locking element that translates along one or more guides arranged on the upper part of said main body. In fact, said locking element comprises a substantially annular upper part with external thread, such as to be coupled with the internal thread of said ring nut, and one or more elastic teeth positioned at the bottom of said annular part.
Said guide of said main body comprises one or more inclined surfaces converging towards the lower part of said main body. Said elastic teeth, translating parallel to the axis of said main body, bend at the level of said inclined surface of said guide of said main body, converging towards the central axis of said main body.
In this way, when said ring nut is rotated, said locking elements translate downwards and bend, thus reducing the cross section of the axial hole of the main body; in this way, said locking elements exert pressure on the external surface of the electric cable, in such a way as to maintain it in its position and prevent it from coming off.
Considering that in the new plug connector it is not the ring nut that translates along the axis of said main body but the locking elements, it is evident that the size of the connector will not change.
In the new plug connector it is not necessary any longer to withdraw said ring nut from the main body, so that the threads are no more exposed to weather agents.
In order to prevent the ring nut from coming off and leaving the electric contacts of the cable and of the outlet or plug element dangerously exposed, the new plug connector is provided with a locking device that prevents the rotation of the ring nut.
These and other direct and complementary objects have been achieved through the construction of the new plug connector.
Connector for outlets and plugs comprising a main body provided with a compartment for the electric cable and with a seat for the outlet or plug element, a locking element with an annular part threaded on the outside, comprising one or more elastic teeth, and a ring nut that can be rotated in relation to said main body, provided with an internal thread coupled with said external thread of said locking element so that, on rotation of said ring nut, said locking element translates axially in relation to said ring nut and said main body, and wherein said elastic teeth of said locking element, resting on inclined sliding guides that are integral with said main body, converge towards the electric cable.
The attached drawings show, as a non-limiting example, a practical embodiment of the new plug connector.
Figure 1a shows an exploded view of the new plug connector (CV) while Figure 1b shows a detail of the ring nut (C) and of the locking element (SB) of the same plug connector (CV).
Figures 2 and 3 show two axonometric sectional views of the new plug connector (CV).
With reference to Figure 2, it can be observed that the new plug connector (CV) comprises a main body (CP), an outlet or plug element (ES) positioned in the lower part of said main body (CP), one or more locking elements (SB), a ring nut (C) with internal thread (FC) positioned on the upper part of said main body (CP), and a device for locking the rotation of said ring nut.
Said substantially cylindrical main body (CP) comprises an axial hole (FA) suited to allow the passage of the electric cable (CE), a further side hole (FL) in proximity of the upper part of said main body (CP), such as to be able to house said locking device (VB), one or more guides (GCP) suitable for the translation of said locking elements (SB), and one seat positioned at the bottom of said main body (CP) for housing said outlet or plug element (ES). The outer lateral surface of said main body (CP), if necessary, can be provided with an annular eyelet or grip (M) suited to make it easier to hold the new plug connector (CV).
In order to comply with the safety regulations in force, the material used to make the main body (CP) must have suitable dielectric strength, in such a way as to guarantee adequate electrical insulation. Furthermore, the material must feature good resistance to impacts and heat and good self-extinguishing properties.
Said seat, present on the lower part of said main body (CP), is shaped in such a way as to allow insertion of the plug element (ES) or, if this is the case, of the outlet element. Furthermore, said plug or outlet element (ES), in this case, is fixed to said main body (CP) by means of a screw (V).
The plug element (ES) has the function of housing the metal wires (CM) of the electric cable (CE) and allow them to be inserted into an outlet.
No further details of said plug or outlet element (ES) will be described herein, since it is not the subject of the present patent.
Said locking elements (SB) are positioned in said guides (GCP) present on the upper part of said main body (CP).
Said locking element (SB) comprises a substantially annular part (ASB) with external thread (FSB), such as to be coupled with said internal thread (FC) of said ring nut (C), and one or more elastic teeth (DSB) positioned at the bottom of said annular part (ASB) of said locking element (SB).
Said guide (GCP) of said main body (CP) comprises a (substantially) inclined surface converging towards the lower part of said main body (CP). Said locking elements (SB), translating along the axis of said main body (CP), bend at the level of said guide (GCP) of said inclined surface of said main body (CP).
Said ring nut (C), substantially cylindrical in shape and comprising an axial hole, is provided with an internal thread (FC), such as to be screwed in said thread (FSB) of said locking elements (SB). Said ring nut (C) is arranged on the upper part of said main body (CP).
When said ring nut (C) is rotated, said locking elements (SB) translate downwards and bend, thus reducing the cross section of the axial hole (FA) of said main body (CP); in this way, said locking elements (SB) exert pressure on the external surface of the electric cable (CE), in such a way as to maintain it in its position and prevent it from coming off.
Said main body (CP) comprises an external annular seat (S) for inserting one or more projections or small teeth (RC) positioned inside said ring nut (C) and suited to prevent said ring nut (C) from coming off.
Furthermore, said ring nut (C) is provided with one or more seats or cavities (SC) in the shape of a sector of a circle, obtained on the lower edge of said ring nut (C), so that said properly shaped locking device (VB) can, if necessary, prevent the rotation and the consequent translation of said locking elements (SB).
Said locking device (VB) arranged on the side hole (FL) of the main body (CP), in proximity of the lower edge of said ring nut (C), comprises a shaft without thread and a substantially flat head (TVB), in this case in the shape of a sector of a circle.
Said locking device (VB) is inserted by pressare in said lateral body (FL) of said main body (CP), with the function of locking the rotation of the ring nut (C); in fact, if said locking device (VB) is rotated so that the flat part of said head (TVB) of said locking device (VB) faces upwards, said ring nut (C) can rotate freely; on the contrary, the rotation of said ring nut (C) can be locked by inserting the curved side of said head (TVB) of said locking device (VB) into one of said seats (SC) in the lower edge of said ring nut (C). In order to facilitate the rotation of said locking device (VB), its head is provided with a cross cut (TC) for the insertion of tools.

Claims

Connector for outlets and plugs (CV), characterized in that it comprises:
• a main body (CP) with a compartment for the electric cable (CE);

• at least one locking element (SB), with a part (ASB) threaded on the outside (FSB), and one or more teeth (DSB);

• a ring nut (C) that can be rotated in relation to said main body (CP) and is provided with an internal thread (FC) coupled with said external thread (FSB) of said locking element (SB), and wherein, on rotation of said ring nut (C), said locking element translates axially in relation to said ring nut (C) and said main body (CP), so that said teeth (DSB) of said locking element (SB), resting on sliding guides (GCP), converge towards the electric cable duct.
Connector for outlets and plugs (CV) according to claim 1, characterized in that it comprises a device (VB) for locking the rotation of said ring nut (C).
Connector for outlets and plugs (CV) according to claims 1, 2, and 3, characterized in that said ring nut (C) surrounds the upper part of said main body (CP).
Connector for outlets and plugs (CV) according to claims 1, 2, 3, and 4, characterized in that said annular element (ASB) of said locking element (SB) is positioned coaxially and/or in the upper part of said main body (CP).
Connector for outlets and plugs (CV) according to the preceding claims, characterized in that said main body (CP) comprises an external annular seat (S) for inserting at least one projection or small tooth (RC) positioned inside said ring nut (C) and suited to prevent said ring nut (C) from coming off said main body (CP).
Connector for outlets and plugs (CV) according to the preceding claims, characterized in that said main body (CP) comprises an annular eyelet or grip (M).
Connector for outlets and plugs (CV) according to claim 2, characterized in that said locking device (VB) of said ring nut (C), positioned in proximity of the edge of said ring nut (C), comprises a shaft without thread and a head (TVB) in the shape of a sector of a circle, and in that said ring nut (C) comprises seats or cavities (SC) in the shape of a sector of a circle obtained on the edge of said ring nut (C), and wherein said seats or cavities (SC) are suited to house the curved part of said head (TVB) of said locking device (VB).