The present invention relates to an electrical connector, and more particularly to an arc suppressing electrical connector subjected to a high voltage.
Power and signal distribution connectors mechanically and electrically connect at least two conductors at, ideally, the lowest possible power loss. Connectors are not designed to make and break a hot electrical circuit as are switches, relays and contactors. Nevertheless, during their service life connectors can be plugged and unplugged under load many times (i.e. “hot plugged”). Very often this disconnection under load occurs when physically switching off the power in advance would be considered time consuming and inconvenient. Also, connectors in automotive power networks are plugged and unplugged under load during diagnostic procedures, fuses are plugged at short circuit conditions, and so forth. Under some circumstances in the above situations, the connector suffers no significant damage with multiple engages/disengages. Other times, just one disconnect damages the terminals beyond repair. In other words, under specific conditions, a long arc may be generated at engage/disengage, which may cause extensive terminal erosion. This erosion may damage the physical shape of the terminal, preventing re-engagement or proper terminal contact forces after disengagement.
Traditionally, the automotive industry utilizes a 14 volt direct current, VDC, power network. With such low voltages, no serious consequences are associated with plugging and unplugging under load due to very spatially short break arcs (the arc energy remains below that required to damage the contact material). However, the world's leading car manufactures and component suppliers are promoting 42 VDC power networks. Unfortunately, multiple matings and disconnects of a 42 VDC automotive network damages a standard connector terminal beyond repair because the break arcs are much longer and associated energy is higher. In other words, under specific conditions, a long arc may be generated at matings or disconnects which may cause high contact erosion. This erosion may damage the physical shape of the 42 VDC terminal preventing re-mating or hindering proper terminal contact forces after assembly.
Accordingly, it would be highly desirable if such arcs could be suppressed or quenched as soon as possible reducing the arc energy exposed to the contacts to eliminate contact erosion.
An arc quenching electrical connector has a terminal, preferably a male pin, which inserts longitudinally into a mating terminal or receptacle having a gassing wall engaged concentrically and directly about the receptacle. During “hot unplugging” of the electrical connector, an arc can occur and would be carried between a tip of the male pin and a contact surface of a leading end of the receptacle. The gassing wall extends over and is engaged directly to a portion of the contact surface. The contact surface preferably has an annular portion orientated closest to the tip of the male pin and a radial portion facing inward and engaged congruently to the inner perimeter of the annular portion. The gassing wall substantially extends over and is engaged directly to the annular portion of the contact surface.
Because the gassing wall is preferably an electrical insulator, a root of the arc does not substantially contact the annular portion of the contact surface which is closest to the tip of the male pin, but instead, directly contacts the radial portion of the contact surface. The arc root is therefore biased against or is adjacent to the gassing wall. This very close proximity of the arc to the gassing wall enhances the arc's ability to quickly heat the gassing wall through the metallic receptacle. When heated, the gassing wall preferably releases hydrogen gas which creates a pressure surge that bends the arc thereby causing the arc to reach its break arc length sooner which reduces the energy exposed to the contacts when hot unplugging/plugging the connector. The high thermal conductivity of hydrogen gas also serves to cool the arc root which dissipates the arc energy away from the contact surfaces.
An advantage of the present invention in the ability to quench an arc when “hot plugging or unplugging” an electrical connector which substantially reduces arc produced terminal erosion.
Another advantage of the present invention is the ability to manufacture automotive power networks having voltages in excess of 14 VDC.
The presently preferred embodiments of the invention are disclosed in the following description and in the accompanying drawings, wherein:
As previously noted,
During “hot un-plugging” of the electrical connector 26, the second terminal or male pin 14 is withdrawn longitudinally through a rearward hole 28 defined at the end of a metallic or stainless steel outer sleeve 30 of the receptacle 12 from a forward hole 32 defined by an inner spring contact sleeve 34 disposed concentrically within and engaged to the outer sleeve 30. The contact sleeve 34 is flexed resiliently and radially outward to provide a lateral inward force against the male pin 14 thereby achieving a reliable electrical connection.
The electrical connector 26 has a characteristic terminal proximity zone 36 which is substantially shorter than the terminal proximity zone 20 of the known connector 10 attributable to the gassing wall 24 which externally surrounds and is engaged directly and concentrically to the outer sleeve 30 of the receptacle 12. The smaller the proximity zone 36, the lower the arc energy transferred to the terminals 12, 14 and the smaller the opportunity for contact erosion. The trailing rear end contact surface 16 of the outer sleeve 30 has a substantially annular portion 40 which faces rearward and a radial portion 42 which is exposed or faces radially inward and opposes the male pin 14 when the electrical connecter 26 is mated. The proximity zone 36 is generally measured axially between the annular portion 40 of the receptacle 12 and the contact tip or surface 18 of the disengaged male pin 14.
The outer limit or maximum distance of the proximity zone 36 is dictated by the extinguishing or quenching point of the arc 22. In other words, as the contact surface 18 of the male pin 14 moves rearward from the annular portion 40 of the receptacle 12 within a “hot” circuit, the voltage of the resultant arc 22 continues to increase while the current decreases simultaneously. The arc 22 dissipates when the current reaches zero. At the point of arc dissipation, dictated by the circuit voltage and current, the distance between the contact surface 18 and the annular portion 40 generally establishes the outer limit of the proximity zone 36. The higher the circuit voltage, the longer the proximity zone 36 tends to be. Because energy is directly proportion to the product of voltage, current and time, it is preferable to reach current zero as soon as possible, thereby decreasing arc induced erosion and melting of the contacts by reducing the total energy exposed to the contact surfaces.
The gassing wall 24 accomplishes this reduction in energy, thereby favorably shortening the proximity zone from the zone 20 of the prior art in
Unlike the art of electrical switches, the gassing wall 24 is engaged directly to a substantial portion of the annular portion 40 of the contact surface 16 and is thereby disposed axially between the contact surface 18 of the male pin 14 and the contact surface 16 of the receptacle 12. Therefore, and because the gassing wall 24 also has electrical insulating characteristics, an arc root 46 of the arc 22 electrically contacts the radial portion 42 instead of the closer annular portion 40 of the contact surface 16. Yet, the energy transmitting root 46 is biased against the gassing wall 24 directly adjacent to the closer annular portion 40 because the arc 22 has a tendency to travel the shortest distance between two oppositely charged contact surfaces. Because of this close proximity, the root 46 of the arc 22 heats the high thermally conductive metallic outer sleeve 30 which in turn heats the adjacent gassing wall 24. The substantial heat flow direction is designated by arrows 47 of FIG. 2. As the gassing wall 24 heats, it releases the hydrogen gas 49 which in turn creates a pressure front or wave within the adjacent proximity zone 36 that bends the arc 22, and simultaneously cools the root 46 of the arc 22, thereby dissipating the energy of the arc 22. This is unlike the art of switches which utilize gas to cool the column of the arc, not the root.
Referring to
The gassing wall 24 can be made of a polymer material such as flame retardant polyolefin rubber, neoprene or polypropylene and may further take the form of heat shrink tubing or ceramic as suggested and illustrated by FIG. 2. Referring to
Referring to
Although the preferred embodiments of the present have been disclosed various changes and modifications may be made thereto by one skilled in the art without departing from the scope and spirit of the invention as set forth in the invented claims. Furthermore, it is understood that the terms used here are merely descriptive rather than limiting and various changes may be made without departing from the scope and spirit of the invention.
This patent application claims priority of Provisional Patent Application No. 60/303,652 filed Jul. 6, 2001.
Number | Name | Date | Kind |
---|---|---|---|
3860322 | Sankey et al. | Jan 1975 | A |
3958855 | Oakes | May 1976 | A |
4186985 | Stepniak et al. | Feb 1980 | A |
4192572 | Stanger et al. | Mar 1980 | A |
4464004 | Hegyi et al. | Aug 1984 | A |
4843199 | Niemeyer | Jun 1989 | A |
4863392 | Borgstrom et al. | Sep 1989 | A |
5213517 | Kerek et al. | May 1993 | A |
5401173 | Grandchamp et al. | Mar 1995 | A |
5462453 | Muller | Oct 1995 | A |
5475193 | Perdoncin | Dec 1995 | A |
5530047 | Watanabe et al. | Jun 1996 | A |
5717183 | Lehmann et al. | Feb 1998 | A |
5775930 | Model et al. | Jul 1998 | A |
5925863 | Zehnder et al. | Jul 1999 | A |
5990440 | Yamaguchi et al. | Nov 1999 | A |
6017971 | Mizoguchi et al. | Jan 2000 | A |
6071153 | Fink et al. | Jun 2000 | A |
6142813 | Cummings et al. | Nov 2000 | A |
6162085 | Chugh et al. | Dec 2000 | A |
6168445 | Seutschniker et al. | Jan 2001 | B1 |
6171146 | Fink et al. | Jan 2001 | B1 |
6176746 | Morello et al. | Jan 2001 | B1 |
6179658 | Gunay et al. | Jan 2001 | B1 |
6203364 | Chupak et al. | Mar 2001 | B1 |
6210186 | Fink et al. | Apr 2001 | B1 |
6213795 | Drescher et al. | Apr 2001 | B1 |
6247965 | Cummings et al. | Jun 2001 | B1 |
6276960 | Schaefer et al. | Aug 2001 | B1 |
6305957 | Fink et al. | Oct 2001 | B1 |
6338651 | Svette, Jr. et al. | Jan 2002 | B1 |
6361356 | Heberlein et al. | Mar 2002 | B1 |
6379162 | Raypole et al. | Apr 2002 | B1 |
6383033 | Politsky et al. | May 2002 | B1 |
6406307 | Bungo et al. | Jun 2002 | B2 |
6416119 | Gericke et al. | Jul 2002 | B1 |
6422881 | Puhl et al. | Jul 2002 | B1 |
6485318 | Schoepf | Nov 2002 | B1 |
6485337 | Hsieh | Nov 2002 | B2 |
6494751 | Morello et al. | Dec 2002 | B1 |
6508666 | Francis | Jan 2003 | B1 |
6527573 | Stein, Sr. et al. | Mar 2003 | B2 |
6533611 | Morello et al. | Mar 2003 | B2 |
6537099 | Herlinger et al. | Mar 2003 | B2 |
6547605 | Daugherty et al. | Apr 2003 | B2 |
6565372 | Bakker et al. | May 2003 | B2 |
6607393 | Raypole et al. | Aug 2003 | B2 |
Number | Date | Country |
---|---|---|
1-157013 | Jun 1989 | JP |
Number | Date | Country | |
---|---|---|---|
20030008542 A1 | Jan 2003 | US |
Number | Date | Country | |
---|---|---|---|
60303652 | Jul 2001 | US |