Arc motivation device

Abstract

A circuit interrupter including an arc extinguisher which functions to arrest an arc that develops between electrical contacts. The circuit interrupter includes a permanent magnet coupled at opposite ends to two magnetically permeable pole pieces that are configured to drive or urge an arc into toward an arc extinguisher. The device allows for arc motivation due to the magnetic field without requiring the use of electrical power and allows for a rugged, light-weight design.

Claims

1. A circuit interrupter including arc suppression comprising: a first contact electrically connectable to a power source; a second contact electrically connectable to a load; said first and second contacts being movable between a closed and open position relative to each other; an arc extinguisher for extinguishing an arc that develops in the vicinity of said first and second contacts; a permanent magnet disposed in the vicinity of at least one of the contacts, said permanent magnet having a first end having a first magnetic polarity and a second end having a second magnetic polarity opposite to the first magnetic polarity, said permanent magnet generating a magnetic field; a first pole piece comprising a magnetically permeable material; a second pole piece comprising a magnetically permeable material, said second pole piece positioned apart from and substantially parallel with said first pole piece to form a gap where said first and second contacts are positioned; said first pole piece positioned adjacent to the first end having the first magnetic polarity and said second pole piece positioned adjacent to the second end having the second magnetic polarity; a non-magnetic pole structure having: a first non-magnetic pole piece extending along a longitudinal length of said first pole piece and positioned in the gap between said first pole piece and said contacts; a second non-magnetic pole piece extending along a longitudinal length of said second pole piece and positioned in the gap between said second pole piece and said contacts; and a non-magnetic connecting portion connecting one end of said first non-magnetic pole piece to one end of said second non-magnetic pole piece, said non-magnetic connecting portion positioned in the gap between said permanent magnet and said contacts; wherein the magnetic field extends across a gap formed between the first and second pole pieces such that an arc that forms in the gap is drawn in a direction toward said arc extinguisher.

2. The circuit interrupter according to claim 1 wherein said first non-magnetic pole piece extends a longitudinal length that is substantially equal to a longitudinal length of said first pole piece, and said second non-magnetic pole piece extends a longitudinal length that is substantially equal to a longitudinal length of second first pole piece.

3. The circuit interrupter according to claim 1 wherein said non-magnetic connecting portion is formed as a magnet retainer.

4. The circuit interrupter according to claim 3 wherein said first and second non-magnetic pole pieces and said magnet retainer are all formed as a single unitary structure comprising a non-magnetic structure.

5. The circuit interrupter according to claim 4 wherein an exterior surface of said first and second non-magnetic pole pieces each comprise a cavity with a raised perimeter edge that extends at least partially around a perimeter of each of said first and second non-magnetic pole pieces.

6. The circuit interrupter according to claim 5 wherein each of said first and second pole pieces are positioned in the respective cavities located in the exterior surfaces of each of said first and second non-magnetic pole pieces.

7. The circuit interrupter according to claim 6 wherein the raised perimeter edges extends upwards from the exterior surface of said first and second non-magnetic pole pieces such that they are essentially flush with an outer surface of the respective pole piece positioned in the respective cavity.

8. The circuit interrupter according to claim 4 wherein an interior surface of said first and second non-magnetic pole pieces each comprise a plurality of raised portions that run traverse to a longitudinal length of said first and second non-magnetic pole pieces.

9. The circuit interrupter according to claim 1 wherein said permanent magnet consists of a single permanent magnet having rectangular shape.

10. The circuit interrupter according to claim 1 wherein said first and second pole piece each comprise steel.

11. The circuit interrupter according to claim 1 wherein said first pole piece comprises a flat structure having a width and a longitudinal length defined by a first end and a second end, where the longitudinal length is greater than the width.

12. The circuit interrupter according to claim 11 wherein the first end of said first pole piece is positioned in the vicinity of the first end of said permanent magnet, and a width of the first end of the first pole piece is greater than a width of the second end of the first pole piece.

13. The circuit interrupter according to claim 1 said first pole piece is positioned in contact with the first end of said permanent magnet and said second pole piece is positioned in contact with the second end of said permanent magnet.

14. The circuit interrupter of claim 1, wherein said arc extinguisher comprises a first arc path and a second arc path.

15. The circuit interrupter of claim 14, wherein the first arc path extends in a direction substantially parallel to the second arc path.

16. The circuit interrupter of claim 14, wherein the first arc path extends in a direction substantially perpendicular to the second arc path.

17. The circuit interrupter of claim 1, wherein said first and second contacts are positioned one above the other and said permanent magnet is positioned below both said first and second contacts.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates components of an example circuit interrupter according to aspects of the invention.

(2) FIG. 2 is an exploded view of two pole pieces, a magnet and a retainer according to aspects of the invention.

(3) FIG. 3 is a side view according to FIG. 2.

(4) FIG. 4 is a section view along section A-A of FIG. 3.

(5) FIG. 5 is a section view along section B-B of FIG. 3.

(6) FIG. 6 is an overhead view according to FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIG. 1 illustrates components of an example circuit interrupter 100 having magnetic arc extinguishment features according to aspects of the invention.

(8) Circuit interrupter 100 may be any device which can be used to make and break an electrical circuit. For example, it will be clear to those of skill in the art that circuit interrupter 100 may comprise a switch, or may be implemented as a circuit breaker.

(9) Circuit interrupter 100 includes stationary contact 110, which is electrically connected to line terminal (not shown). The line terminal receives electrical power from a power source (not shown), which in some applications is supplied by a power company. It will, however, be understood by those of skill in the art that the power may be provided and conditioned by any commercial means including, but not limited to, a commercial electrical power grid, a generator(s), solar panels, fuel cells, and so on.

(10) A movable contact 120 is disposed on a movable contact arm 140, which is movable between a closed and an open position relative to the stationary contact 110. In FIG. 1, contact arm 140 is shown in a closed position, with movable contact 120 physically contacting stationary contact 110. It will be understood by those of skill in the art that contact arm 140 may be moved upward rotating about a pivot point such that moveable contact 120 is moved out of physical contact with stationary contact 110.

(11) Movable contact 120 is connected to load terminal 130 through a conductor 150. When contact arm 140 is in the closed position as shown, movable contact 120 is electrically connected to stationary contact 110 such that electrical current is allowed to flow between line terminal and load terminal.

(12) Pole pieces 170 and 170 (FIGS. 2-6), may be disposed on opposite sides of the contacts 110, 120 and oriented to produce magnetic fields through the region where an arc may form between contacts 110, 120. A permanent magnet 160 may further be positioned below stationary contact 110 and movable contact 120, and oriented such that the pole pieces 170, 170 are in physical contact with opposite ends of the permanent magnet 160.

(13) Contact arm 140 may be actuated via a switch, trip mechanism, and/or any other known mechanism (not shown) depending on the desired implementation of circuit interrupter 100.

(14) It will be understood that pole pieces 170, 170 will need to be positioned in such a manner that they do not obstruct the travel of contact arm 140. This arrangement provides the advantage of creating magnetic fields, which maintain a desired field strength and direction over the expected travel path of an arc generated between contacts 110, 120. In the example depicted in FIG. 5, pole pieces 170 and 170 are oriented such that the magnetic field produced by magnet 160 flows from one pole piece to the other and encourages an arc toward arc extinguisher 205.

(15) FIG. 2 provides an exploded view of a portion of the circuit interrupter 100 illustrating an example of one configuration for the pole pieces 170, 170 and the permanent magnet 160. In this example, a structure comprising a non-magnetic material is provided including two upturned pieces 172, 172 that run essentially parallel to each other and are connected at a lower end by an end piece 174 that also comprises a non-magnetic material. The two upturned pieces 172, 172 and the end piece 174, may in one example, comprise a single unitary structure.

(16) Provided on an exterior surface of the upturned piece 172 is a cavity 176 that is provided substantially to receive pole piece 170 therein. While not depicted, it should be understood that a corresponding cavity is provided on an exterior surface of upturned piece 172 that is provided to receive the corresponding pole piece 170 therein.

(17) On an interior surface of upturned piece 172 are raised protrusions 178 that are provided traverse to a longitudinal length of upturned piece 172. While five (5) protrusions 178 are illustrated in the drawing, it will be understood by one of skill in the art that any number may be provided.

(18) The permanent magnet 160 is provided below and is affixed, in one example, to end piece 174. The pole pieces 170, 170 are fitted into their respective cavities of upturned pieces 172, 172 such that the lower ends of the pole pieces 170, 170 come into contact with opposite ends of permanent magnet 160. This functions to magnetize the pole pieces 170, 170 in a manner consistent with the magnetic polarity of the end of the permanent magnet 160 they are connected to. In other words pole pieces 170, 170 will assume opposite polarities.

(19) Turning now to FIGS. 3-5, FIG. 3 illustrates a side view of the pole piece 172 with two section views (A-A and B-B) indicated thereon.

(20) FIG. 4 is a drawing according to FIG. 3 along section line A-A showing the permanent magnet 160 coupled to both pole pieces 170, 170, which are fitted into the cavities of upturned pieces 172, 172. In this example, the upturned pieces 172, 172 and end piece 174 are all formed of a non-magnetic material as a single unitary structure. Also illustrated in FIG. 4 are magnetic lines of force 182, which are provided to illustrate the magnetic field that is developed in the gap 180 between pole pieces 170, 170. The function of the magnetic field 182 will be discussed in greater detail in connection with FIG. 6.

(21) FIG. 5 is a drawing according to FIG. 3 along section line B-B showing both pole pieces 170, 170 and the interaction of the magnetic field 182 with and arc that forms in the gap 180.

(22) FIG. 6 is a top view of pole pieces 170, 170 and illustrates the effect of magnetic field 182 upon an arc developing between contacts 110, 120.

(23) For example, in FIG. 6, an arc 500A is illustrated developing between stationary contact 110 and movable contact 120. An electromagnetic field 510A surrounding arc 500A is developed in a counter-clockwise direction as indicated. Electromagnetic field 510A interacts with magnetic field 180 to move arc 500A in the direction illustrated by arrow 520A (i.e., to the right in FIG. 6). Referring to the corresponding structures in FIG. 1, this movement will drive the arc 500A toward arc extinguisher 205 to be extinguished.

(24) Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many modifications and variations will be ascertainable to those of skill in the art.