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Publication numberUS3512043 A
Publication typeGrant
Publication dateMay 12, 1970
Filing dateNov 9, 1967
Priority dateNov 9, 1967
Publication numberUS 3512043 A, US 3512043A, US-A-3512043, US3512043 A, US3512043A
InventorsJaaksoo Lembit, Johansson Arne, Stange Werner
Original AssigneeAsea Ab
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Means for short-circuiting the secondary circuit of a current transformer
US 3512043 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

May 12, 1970 L. JAAKSOO ETAL 3,512,043


A (m l ro H 1 N550 N warm bx 5 A (HE United States Patent U.S. Cl. 31714 2 Claims ABSTRACT OF THE DISCLOSURE A device for short-circuiting the secondary circuit of a transformer when a contact making device is removed from such circuit comprises a body of insulating material in which is slidably mounted a short-circuiting member which is pushed into a position by a spring to make contact with two jacks when the contact making device is removed, so as to short-circuit the transformer. When the contact making device is replaced, a pin engaging a pin on the short-circuiting member pushes it to another position in which it no longer short-circuits the secondary.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to an arrangement for shortcircuiting a secondary circuit of a current transformer when a relay or other device is removed from such clrcuit.

The prior art When disconnecting electrical apparatus which are directly connected to a current transformer there is a great risk that the secondary circuit of the current transformer will be opened involuntarily. This is the case especially with apparatus of the plug-in type, for example, relays. Usually some type of switch-over with non-interrupting contacts is used for short-circuiting the secondary circuit before the apparatus is removed from its mounting plate. As the switchover is operated manually, there is always a risk that the short-circuit is not brought about, which results in an opening of the secondary circuit and risks of damage to the current transformer.

Summary of the invention With a device according to the invention an automatic short-circuiting of the secondary circuit is obtained when the apparatus is removed. The short-circuiting is brought about before the apparatus is removed and the risk of damaging the current transformer is completely eliminated.

The essential characteristic for the invention is that the device consists of a socket of insulating material and a short-circuiting body which is movably arranged in an aperture in the socket. The body is actuated partly by a spring mounted in the aperture and partly by a pin on the apparatus. The contact arrangement in the device consists of two contact parts which are connected to the secondary circuit of the current transformer. When the apparatus is removed the body is situated in one of its end positions under influence of the spring where it brings about a shortcircuit between the two mentioned contact parts. When the apparatus is inserted the body is situated at its second end position under the influence of the pin in the apparatus whereupon the short-circuit is nullified.

Brief description of the drawing The attached drawing shows the structure of the invention when applied to a relay of the plug-in type.

Description of the preferred embodiments In the modification shown in the drawing, the device is inserted in a mounting plate 1. The device consists of a socket 2, in which there is an aperture 3, in which a short-circuiting body 4, is arranged. The body at its centre part 5, is actuated by a pressure spring 6, which is in contact with a bottom surface 7 in the aperture and presses the body to the left in the figure. The free ends of the body are bent in order to obtain a good contact surface, partly against two contact parts 9, partly against a slanting surface 10 in the aperture. The contact parts 9 are shaped as contact jacks inserted in tubes 11 in the socket. At their right end the jacks are connected to a cable from the secondary circuit of a current transformer which is not shown.

Of the relay which is to be connected, only the bottom socket 20, two plugs 21 and a pin 22 are shown in the figure. When the relay is mounted on the mounting plate the plugs 21 enter the jacks 9, and by this the relay is connected to the secondary circuit of the current transformer. The pin 22 is intended to cooperate with a guide pin 14 in the body 4 and to press the body to the right when the relay is inserted in its place. When moved to the right, the body is compressed slightly and its free ends are slid along the edges 15 in the aperture so that the short-circuit is broken. The lengths of the guide pin 14, pin 22 and the two plugs 21 on the relay are so dimensioned that upon insertion of the relay into the socket the plugs 21 have good contact with the contact jacks 9 before the body 4 is pressed so far to the right that the short-circuiting between the contact parts 9 is broken. Upon the removing of the relay the body 4 will have brought about a short-circuit of the secondary circuit before the plugs 21 have left the contact jacks 9.

We claim:

1. Device for short-circuiting the secondary circuit of a current transformer simultaneously with the removing of an apparatus which is connected to said current transformer by means of said device, said device comprising a socket of insulating material having an aperture therein, a short-circuiting means movably arranged in said aperture, a pressure spring in said aperture and a pin on said apparatus for moving said short-circuiting means in opposite directions, said socket having tubes therein on opposite sides of said aperture and communicating therewith, two contact jacks in said socket connected to the secondary circuit of said current transformer, each said contact jacks being positioned in one of said tubes, said short-circuiting 4 means engaging in direct contact with said contact jacks References Cited when the apparatus is removedfrom the soclret, said con- UNITED STATES PATENTS tact acks being arranged for direct cooperation with corresponding contact pins on the apparatus. g 1;9 2: 3%? 2. A device acco din to claim 1, said short-circuitin I I g g 5 3,243,773 3/1966 Leichsenring zoo-41.10 X

body being provided with a guide pin which cooperates with said pin of said apparatus, the length of the guide pin and said pin in the apparatus being such that the apparatus JAMES TRAMMELL Pnmary Exammer is electrically connected to the current transformer before U S cl X R the short-circuit is broken upon inserting of an apparatus 10 in the socket. ZOO-51.10; 336-107

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2747049 *Feb 1, 1954May 22, 1956Anchor Mfg CompanyPlug-in meter socket with shunt switch and signal
US3208021 *Sep 12, 1962Sep 21, 1965Astra CorpShorting switch mechanism
US3243773 *Apr 29, 1965Mar 29, 1966Max LeichsenringControl means for the selective energization of an electrically energizable device from an electrical potential source
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3692966 *Jul 22, 1970Sep 19, 1972Cooke Eng Co TheMulti-circuit patch plug and jack
US3903385 *Oct 25, 1973Sep 2, 1975E Advanced Packaging Inc SaShorting bar switch in electrical connector biasing assembly
US4053724 *Jun 19, 1975Oct 11, 1977Jesus Gomez LlonaPanel and plural module assembly having mechanical keying and modular plug structure to activate/deactivate automatically bridged load carrying circuits
US4151576 *Oct 31, 1977Apr 24, 1979General Electric CompanyTransformer secondary disconnect and shorting switch
US4256936 *Oct 27, 1978Mar 17, 1981Dynatech Laboratories, Inc.Electrical jack and patch cord assemblies
US4594490 *Nov 8, 1984Jun 10, 1986At&T Bell LaboratoriesTerminal pin shorting switch apparatus
US4904196 *Jul 14, 1988Feb 27, 1990Yazaki CorporationReleasable connector for electric circuits
US4988307 *Oct 10, 1989Jan 29, 1991Itt CorporationCircuit shorting connector
US5145391 *Apr 29, 1991Sep 8, 1992Gte Products CorporationSwitching connector assembly
US5201853 *Apr 24, 1992Apr 13, 1993Gte Products CorporationSwitching connector assembly
US5275575 *Oct 9, 1992Jan 4, 1994Trw Inc.Electrical connection system with safety interlock
US5277602 *Nov 25, 1992Jan 11, 1994Yi Lee MElectrical plug and receptacle assembly
US5314345 *Oct 9, 1992May 24, 1994Trw Inc.Electrical connection system with interlock
US5505631 *Jun 10, 1994Apr 9, 1996Kabelmetal Electro GmbhDevice to connect an explosive charge with an electric current source
US5600108 *Aug 29, 1994Feb 4, 1997Bed-Check CorporationDocking module enclosure including connectors and power switching
US6198233Nov 13, 1998Mar 6, 2001Zeon CorporationNeon sign transformer module and receptacle
US6392360Jan 24, 2001May 21, 2002Zeon CorporationNeon sign transformer module and receptacle
US6618231Feb 27, 2002Sep 9, 2003Zeon CorporationNeon sign transformer module and receptacle
US6788510Jun 12, 2003Sep 7, 2004Zeon CorporationHigh voltage transformer module and receptacle
US7354287 *Oct 31, 2006Apr 8, 2008Caterpillar Inc.Shorting connector
US7616421Nov 30, 2007Nov 10, 2009Caterpillar Inc.Electrical interface system
US7633024 *Apr 3, 2009Dec 15, 2009Tech Patent Licensing, LlcPush rod shunt for light string sockets
US7789685Dec 18, 2006Sep 7, 2010Caterpillar IncElectrical shorting system
US7955102 *Mar 15, 2007Jun 7, 2011Eduardo Pedrosa SantosLocking system to keep movable contacts apart from fixed contacts of a short circuit
DE19702373B4 *Jan 23, 1997Feb 21, 2008The Whitaker Corp., WilmingtonElektrischer Steckverbinder mit einer Kurzschlu▀feder und Kurzschlu▀feder
EP0318644A2 *Aug 27, 1988Jun 7, 1989Ramos Evaristo GarciaA computer connector with an automatic loop closure device
EP0389779A2 *Feb 16, 1990Oct 3, 1990Robert Bosch GmbhMultiple plug-and-socket device
EP0492018A1 *Dec 20, 1990Jul 1, 1992Jean Paul AvocatElectric measuring transformer
WO1986003894A1 *Oct 31, 1985Jul 3, 1986Amp IncA closed loop connector
U.S. Classification361/35, 200/51.1, 439/188, 200/51.00R, 336/107
International ClassificationH01F38/30, H01F38/28, H01R13/703, H01R13/70
Cooperative ClassificationH01R13/7032, H01F38/28, H01F38/30
European ClassificationH01R13/703B2, H01F38/28, H01F38/30