Contact spring arrangement for a relay for conducting and switching high currents

• US 5,583,471 A
• Filed: 05/09/1995
• Issued: 12/10/1996
• Est. Priority Date: 05/15/1992
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Esterl, Robert, Weiser, Josef, Furtwangler, Gerhard, Tamm, Horst
• Primary Examiner(s): DONOVAN, LINCOLN D
• Application Number:
  US08/335,741
• Time in Patent Office: 581 Days
• Field of Search: 335/78-80, 335/124-128, 335/129, 335/130
• US Class Current: 335/78
• CPC Class Codes: H01H 1/54 by magnetic force combined with electrodynamic opening H01H77/101
• CPC Class Codes: H01H 51/2272 comprising rockable armature, rocking movement around central axis parallel to the main plane of the armature H01H51/2227 takes precedence
• CPC Class Codes: H01H 9/38 Auxiliary contacts on to which the arc is transferred from the main contacts using arcing-horns H01H9/46

Abstract

The contact spring arrangement has an elongated contact spring having a rigid connecting leg which extends approximately parallel to the contact spring and conducts the switching current in a direction opposite to the contact spring. On the side opposite the connecting leg the contact spring has a contact piece which co-operates with an opposite counter-contact element having a contact piece. The repulsive forces between the connecting leg and the contact spring become so long that even in the case of the highest short circuit currents no welding of the contacts results when in the case of contact pieces made from silver or a silver alloy the length of the gap formed between the contact spring and connecting leg is at least 20 times larger than the average spring spacing in the gap.

Claims

1. A contact spring arrangement for a relay for conducting and switching high currents comprising:

at least one elongated contact spring which carries a first contact piece and co-operates with a fixed counter-contact element carrying a second contact piece,

at least one rigid connecting leg for the contact spring, the at least one rigid connecting leg extending approximately parallel to the contact spring while forming a spring gap on a side opposite the first contact piece and the at least one rigid connecting leg conducting a switching current in a direction opposite to the contact spring,

the spring gap extending at least approximately over an entire length of the contact spring from a mounting point of the contact spring to the first contact piece, and a ratio of length to spacing in the spring gap approximately satisfies the following condition when the first and second contact pieces are closed;

##EQU8## where L=length of the spring gap

D=average spacing in the spring gap

μ

_o =magnetic field constant=1.256·

10⁶ [Vs/Am]

H_S =limiting heating intensity of current-carrying capacity of contact material ##EQU9## of the first and second contact pieces.

2. The contact spring arrangement as claimed in claim 1, wherein the ratio of the length of the spring gap to the spacing in the spring gap satisfies the following condition:

L/D≧

20.

4. The contact spring arrangement as claimed in claim 1, wherein the contact spring is subdivided into a main spring leg having a main contact piece made from a silver alloy and an advance spring leg having an advance contact piece made from tungsten.

5. The contact spring arrangement as claimed in claim 1, wherein the ratio of the length of the spring gap to the spacing in the spring gap satisfies the following condition:

L/D≧

30.

3. A contact spring arrangement for a relay for conducting and switching high currents comprising:

at least one elongated contact spring which carries a first contact piece and co-operates with a fixed counter-contact element carrying a second contact piece,

at least one rigid connecting leg for the contact spring, the at least one rigid connecting leg extending approximately parallel to the contact spring while forming a plurality of spring gaps on a side opposite the first contact piece and the at least one rigid connecting leg conducting a switching current in a direction opposite to the contact spring,

the plurality of spring gaps extending at least approximately over an entire length of the contact spring from a mounting point of the contact spring to the first contact piece,

the plurality of spring gaps being lined up by folding the contact spring in the manner of an accordion, a sum of gap lengths satisfying the following relationship in relation to an average gap width, when the first and second contact pieces are closed;

##EQU10## where L=length of the spring gap

D=average spacing in the spring gap

μ

_o =magnetic field constant=1.256·

10^-6

H_S =limiting heating intensity of current-carrying capacity of contact material ##EQU11## of the first and second contact pieces.

6. The contact spring arrangement as claimed in claim 3, wherein the contact spring is subdivided into a main spring leg having a main contact piece made from a silver alloy and an advance spring leg having an advance contact piece made from tungsten.

7. The contact spring arrangement as claimed in claim 3, wherein the ratio of the length of the spring gap to the spacing in the spring gap satisfies the following condition.

8. The contact spring arrangement as claimed in claim 3, wherein the ratio of the length of the spring gap to the spacing in the spring gap satisfies the following condition.