Electrical connectors – With sealing element or material for cooperation with...
Reexamination Certificate
1998-10-08
2001-04-10
Bradley, Paula (Department: 2833)
Electrical connectors
With sealing element or material for cooperation with...
C277S606000
Reexamination Certificate
active
06213805
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates in general to a high-voltage (HT) connector, particularly for providing power to X-ray tubes.
The HT current source for powering an X-ray tube is conventionally encased in a box filled with an insulating and cooling medium, generally a mineral oil, while the X-ray tube is itself also encased in another box filled with an insulating and cooling medium, for example a mineral oil.
Depending on the type of HT current source and the type of X-ray tube, whether it is monopole or symmetric, one or more HT cables convey HT current from the source to the X-ray tube. These power leads are connected to the HT source and to the X-ray tube by means of hermetically sealed HT connectors.
These HT connectors generally consist of two parts, a female part or receptacle which is attached permanently to the box and a male part or plug intended to plug into the receptacle to produce electrical continuity and which constitutes the end of the HT cable.
To withstand the high voltages of the source and of the X-ray tube, which may be as much as 150 kV or more, the receptacle and the plug of the HT connector are made of an insulating material and have shapes and sizes which are generally dictated by international standards.
To protect the users, the boxes of the HT source and of the X-ray tube are earthed and an external jacket of the HT cable is also earthed by metal parts of the receptacle and of the plug.
The HT source and the X-ray tube are electrically connected to the HT cable by interacting metal contacts arranged in receptacle of the connectors.
To avoid electrical discharge between the contacts and the metal parts of the connector of the HT source or of the X-ray tube, the gap between the receptacle and the plug is filled with an electrically insulating fluid, for example a mineral oil or grease such as a silicon oil or grease.
To keep this insulating fluid in the gap between the receptacle and the plug, an annular seal is arranged between the open end of the receptacle and a flange of the plug. As the volume of insulating fluid varies with temperature, and in fact increases as the temperature rises, it is necessary, in order to avoid excessively high pressures which could lead to leaks of insulating fluid and even to the destruction of the receptacle with a risk of HT electrical discharge, that this increase in volume of the insulating fluid be compensated.
To compensate for such variations in volume of the insulating fluid, use is made of a boot/ring, the volume of which varies as a function of the pressure of the insulating fluid in order to accommodate the increase in volume of the insulating fluid.
Furthermore, this annular seal needs to operate over a wide temperature range and be chemically able to resist the hot insulating fluid.
A first boot/ring conventionally used is depicted in FIG.
2
. This ring
41
is a ring made of metal which has a accordion side wall
42
. This ring is easy to handle and reliable in the long term but is very expensive to manufacture.
Another boot/ring also used is depicted in FIG.
3
. This composite ring
43
is composed of a flat metal annulus
44
to which an elastomer annulus
45
is attached, forming a half torus inside the metal annulus
44
. This boot/ring is difficult to handle, and requires extremely accurate fitting means to avoid leaks and is expensive.
BRIEF SUMMARY OF THE INVENTION
The purpose of the present invention is therefore to provide a boot/ring for a high-voltage connector which overcomes the drawbacks of the boot/rings of the prior art, and in particular which is reliable, easy to manufacture and inexpensive.
Also, the subject of the present invention is an HT connector comprising a boot/ring of this kind.
An embodiment of the invention is a boot/ring for an HT connector which is composed of an annular core made of a closed-cell elastomer foam entirely coated with a covering made of an elastomer that can withstand the insulating and cooling liquid at the HT connector operating temperature.
For the core of the boot/ring according to the invention, use may be made of any closed-cell elastomer foam, for example, a polyurethane or neoprene foam.
Given that the usual elastomer foams do not have the desired resistance to the insulating and cooling liquid (for example an oil) present in the HT connector, particularly when hot, the elastomer foam is entirely coated with a covering made of elastomer that can resist the insulating and cooling liquid at the HT connector operating temperature.
For the covering, use may be made of any elastomer which satisfies the above requirement. Among the elastomers that can be used, mention may be made of olefin elastomers such as neoprene, elastomeric polyesters, silicone elastomers, halogenated-olefin elastomers, particularly chlorinated olefin elastomers, and polyurethane elastomers.
REFERENCES:
patent: 4327924 (1982-05-01), Wheeler
patent: 4335928 (1982-06-01), Barrett et al.
patent: 4361721 (1982-11-01), Massey
patent: 4903972 (1990-02-01), Ombredane
patent: 5075174 (1991-12-01), Pyle
patent: 5358419 (1994-10-01), Pejsa et al.
patent: 5586776 (1996-12-01), Kubouchi et al.
patent: 5596621 (1997-01-01), Schwarz et al.
Jedlitschka Hans
Siruel Jacques
Bradley Paula
Chaskin Jay L.
Ta Tho D.
LandOfFree
Boot/ring for high voltage connector and high-voltage... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Boot/ring for high voltage connector and high-voltage..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Boot/ring for high voltage connector and high-voltage... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2449721