EP2319064B1

EP2319064B1 - Two-column electrical disconnector

Info

Publication number: EP2319064B1
Application number: EP09741455.1A
Authority: EP
Inventors: Dario Bergamo
Original assignee: Alstom Technology AG
Current assignee: General Electric Technology GmbH
Priority date: 2009-08-13
Filing date: 2009-08-13
Publication date: 2013-06-05
Anticipated expiration: 2029-08-13
Also published as: CN102089844A; WO2011018810A8; WO2011018810A1; EP2319064A1; CN102089844B

Description

Technical field

The present invention relates to a two-column electric disconnector.

Background Art

Two-column disconnectors with rotating arms are currently known.
Such disconnectors have two posts, at the upper ends of which there are provided two arms that can rotate in a coordinated manner about the axis of the posts in order to connect at their free ends.
Of these arms, the one that has a contact head adapted to engage a contact seat provided at the free end of the other arin, known as a female arm, is generally referenced as a male arm.
Upon closure of the disconnector, the contact head engages the contact seat, so as to produce their electrical connection at electrical contacts with which they are provided
The need to obtain an abutment of such contacts that is effective in order to achieve their electrical connection is particularly felt in the field of these devices.
The need to achieve a connection between such contacts that is stable over time is equally strong.
Particularly in the case of disconnectors for networks that operate at high electrical voltages, an uncertain and/or unstable contact induces electric arcs, to the full disadvantage of the safety and working life of the disconnector.
A grounding switch with knife connector is disclosed in DE 12 22 137 .

Disclosure of the Invention

The aim of the present invention is to provide a two-column electrical disconnector that meets these needs by ensuring, when it is closed, a safe electrical connection between its contacts.
Within this aim, an object of the invention is to propose a disconnector that makes it possible to obtain a stable electrical connection between its contacts.
Another object of the invention is to propose a disconnector that is structurally simple and easy to use and can be manufactured at low cost.
This aim, as well as these and other objects that will become better apparent hereinafter, are achieved by a two-column electrical disconnector, according to the invention, that has the features set forth in claim 1.

Brief description of the drawings

Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of the disconnector according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of a detail of a disconnector according to the invention in a partially open configuration;
Figure 2 is a partially sectional enlarged-scale view of a detail of the disconnector according to the invention;
Figure 3 is a sectional view of the disconnector according to the invention, taken along the line III-III of Figure 2;
Figure 4 is a sectional view of the disconnector according to the invention, taken along the line IV-IV of Figure 2.

Ways of carrying out the Invention

It is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer.
With reference to the figures, the reference numeral 10 generally designates a two-column electrical disconnector, which comprises a female arm 12 and a male arm 11, which is provided with a contact head 13 that is adapted to enter a contact seat 14 of the female arm 12.
According to the invention, a particularity of the disconnector 10 is that it comprises a contact head 13 that has contact recesses 15 which have a substantially open V-shaped profile in order to receive, upon closure of the disconnector, contact pads 16 of the female arm 12, with a contact of the type on two points A and B.
The female arm 11 comprises two half- arms 17a and 17b, which are arranged side by side so as to form between them, at a free end thereof, the contact seat 14, having the contact pads 16 thereat.
Moreover, elastic means 18 for contrasting the divarication of the half-arms 17a are 17b are provide, said arms partially divaricating, in contrast with the elastic means 18, when the contact pads 16 engage the contact recesses 15 to close the disconnector 10.
Advantageously, the disconnector 10 comprises means for divarication of the half- arms 17a and 17b upon insertion of the contact head 13 in the contact seat 14, which conveniently comprise:

ramps 19 for divarication of the half- arms 17a and 17b provided thereon in mirror-symmetrical positions at the contact seat 14,
pins 20 for pushing the ramps 19, which are provided at the contact head 13 and are adapted to push the ramps 19 for divarication of the half- arms 17a and 17b during the closure of the disconnector 10.

Preferably, the contact pads 16 and/or the contact elements 21 on which the contact recesses 15 are formed are made of copper.
Moreover, the contact recesses 15 conveniently have a hollow 22 at their bottom 23 in order to contrast the abutment of the contact pads 16 against the bottom 23, when the disconnecter 10 is closed.
This is done to achieve such contact of the type on two points A and B of the contact pads 16 in the contact recesses 15.
The female arm 12 conveniently has means for spacing the half- arms 17a and 17b, to contrast their juxtaposition beyond a predefined distance, which in particular comprise advantageously two brackets 24a and 24b that protrude toward each other from the half- arms 17a and 17b, defining, upon their abutment, such minimum distance.
Preferably, the elastic means 18 comprise a helical spring 25, which surrounds a stem 26 that protrudes from a first bracket 24a of the brackets 24a and 24b toward the second bracket 24b.
The ends 25a and 25b of the spring 25 abut against a shoulder 27 of the stem 26 provided at its free end, and against an abutment 28 formed on the second bracket 24b, to contrast the divarication of the brackets 24a and 24b.
Conveniently, the shoulder 27 is formed by a washer 29, which is retained by a bolt 30 screwed onto a threaded end 31 of the stem 27.
In addition, preferably there are provided sealings 32 for electrical insulation of the stem 27 and of the spring 25 with respect to the brackets 24a and 24b.
Operation of the disconnector according to the invention is as follows.
Upon closure of the disconnector 10, the female arm 12 and the male arm 11 rotate, and the contact head 13, by aligning itself, engages the contact seat 14.
More specifically, during such engagement, the pins 20 abut against the ramps 19'and by pushing against them the half- arms 17a and 17b divaricate in contrast with the spring 25 compressed between the abutment 28 of the second bracket 24b and the shoulder 27 of the stem 26, which is jointly connected to the first bracket 24a.
Substantially simultaneously, the contact pads 16 abut against the contact elements 21, establishing with them an electrical contact in the contact recesses 15, substantially in two points A and B.
When closure of the disconnector 10 is completed, the male arm 11 and the female arm 12 are aligned.
In this configuration, the contact pads 16 are pressed against the contact elements 21 in the contact recesses 15 by the spring 25.
The mutual distance of the contact pads 16 when they engage the contact recesses is such as to force a divarication of the half- arms 17a and 17b, compressing the spring 25 that opposes it, and thus presses the contact pads 16 against the contact elements 21, allowing effective and stable electrical contact between them.
Moreover, the spring 25 is electrically insulated against at least one of the half arms 17a and 17b, so as to avoid the flow of current through it.
In practice it has been found that the disconnector according to the Invention achieves the intended aim and objects, allowing certain and stable electrical connection between its contacts, ensured by the mutual contact thrust produced by the spring,
Further, the disconnector according to the invention is structurally simple and easy to use and can be manufactured at low cost.

Claims

A two-column electrical disconnector (10), comprising a female arm (12) and a male arm (11) that is provided with a contact head (13) and is adapted to enter a contact seat (14) of said female arm (12), wherein said contact head (13) has contact recesses (15) which are open in order to receive, upon closure of said disconnector (10), contact pads (16) of said female arm (12), said female arm (12) comprising two half-arms (17a, 17b) that are arranged side by side so as to form between them, at a free end thereof, said contact seat (14) having thereat said contact pads (16), elastic means (18) for contrasting the divarication of said half-arms (17a, 17b) being provided, said half-arms (17a, 17b) being partially divaricated, in contrast with said elastic means (18), when said contact pads (16) engage said contact recesses (15) upon closure of said disconnector (10), characterized in that each one of said contact recesses (15) has a V-shaped profile and receives a respective one of said contact pads (16) of said female arm (12), establishing therewith an electrical contact in said recess (15) in two points (A, B) upon closure of said disconnector (10) by rotation of said male arm (11) and of said and female arm (12) in coordinated manner for alignment of said contact head (13) with said seat (14) and its engagement therein.
The electrical disconnector according to claim 1, characterized in that it comprises means for divarication of said half-arms (17a, 17b) upon insertion of said contact head (13) in said contact seat (14).
The electrical disconnector according to claim 2, characterized in that said divarication means comprise
- ramps (19) for divarication of said half-arms (17a, 17b) provided on them in mirror-symmetrical positions at said contact seat (14),

- pins (20) for pushing said ramps (19), which are provided at said contact head (13) and are adapted to push said ramps (19) so as to make said half-arms (17a, 17b) divaricate during the closure of said disconnector (10).
The electrical disconnector according to one or more of the preceding claims, characterized in that said contact pads (16) are made of copper.
The electrical disconnector according to one or more of the preceding claims, characterized in that said contact recesses (15) are formed on contact elements made of copper.
The electrical disconnector according to one or more of the preceding claims, characterized in that said contact recesses (15) have a hollow (22) at their bottom (23), to contrast the abutment of said contact pads (16) against said bottom (23) when said disconnector (10) is closed.
The electrical disconnector according to one or more of the preceding claims, characterized in that said female arm (12) has means for spacing said half-arms (17a, 17b) to contrast their juxtaposition beyond a predefined distance.
The electrical disconnector according to one or more of the preceding claims, characterized in that said spacing means comprise two brackets (24a, 24b), which protrude toward each other from said half-arms (17a, 17b), defining said minimum distance upon their abutment.
The electrical disconnector according to one or more of the preceding claims, characterized in that said elastic means (18) comprise a helical spring (25), which surrounds a stem (26) that protrudes from a first one of said brackets (24a, 24b) toward the second one of said brackets (24a, 24b), the ends of said spring (25) abutting, in an electrically insulated manner, against a shoulder (27) of said stem (26) that is provided at its free end, and against an abutment (28) that is formed on said second bracket (24b), to contrast the divarication of said brackets (24a, 24b).