US3430164A - Circuit breaker mechanism - Google Patents

Description

Feb.l25, 1969 l R. L.. HURTLE CIRCUIT BREAKER MECHANISM l of Sheet Filed Sept. 15, 1967 v mn u, IU www.; vLw mm/MA m K y@ Feb. 25, 1969 R. l.. HURTLE '3,430,164

CIR-CUIT- BREAKER MECHANISM Filed Sept. 15, 1967 Shee'cI 2 of 2 United States Patent O M 3,430,164 CIRCUIT BREAKER MECHANISM Ralph L. Hurtle, West Hartford, Conn., assignor to general Electric Company, a corporation of New ork Filed Sept. 15, 1967, Ser. No. 668,088 U.S. Cl. 335-22 5 Claims Int. Cl. Htllh 73/36, 77/06 ABSTRACT OF THE DISCLOSURE An electric circuit breaker operating mechanism including a single operating spring which, in the closed condition of the circuit breaker acts between a support member and a movable contact mem-ber to urge the movable contact to closed circuit position; upon the occurrence of overcurrent, the support member for the spring is released, permitting the spring to accelerate the support member in a -direction away from the movable contact member; the inertia thus built up in the support member and associated parts is utilized by means of a lost-motion connection to the movable contact member, to cause opening movement of the movable contact.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to automatically operable circuit breakers, and particularly to circuit breakers of the type including a movable contact member and spring means for maintaining the contact member in closed circuit position, together with automatically operable means for causing movement of the contact member to open circuit position.

Description of the prior art Prior art mechanisms for electric circuit breakers of the type referred to comprise two main types. The first of these types utilizes a main operating spring and a separate overriding or kick-off spring, which upon the occurrence of predetermined current conditions, is released to act against the contact pressure spring to move the movable contact to open circuit position. The second type utilizes an operating spring and mechanism linkage so arranged that upon the occurrence of predetermined current conditions, the line of action of the spring changes with respect to a given pivot point so as to reverse its bias on the movable contact member and move it to open circuit position.

The first of these types suffers from the disadvantage of requiring two separate springs, and also of having a high latch pressure, complicating the release of the mechanism by automatic current responsive means. Such high latch pressure results from the fact that the overriding or kick-Gif spring must, in its most relaxed condition, be stronger than the operating spring in its most compressed condition. The second type of operating mechanism has the disadvantage of requiring relatively complicated operating mechanisms, and also of being relatively inefficient as regards utilization of spring force, since only a portion of the force of the operating spring is used to produce contact pressure in the closed circuit position of the mechanism, the remaining portion of the force of the spring being utilized to produce the shifting of the line of action of the spring upon release of the latch mechanism.

Objects of the invention It is an object of the present invention to provide a simplified circuit breaker operating mechanism which requires only a single spring to produce force urging the contacts into engagement and also moving them apart,

3,430,164 Patented Feb. 25, 1969 without the necessity of changing the line of action of the spring.

It is another object of the invention to provide an electric circuit breaker operating mechanism of the type described which is simple, eicient, and dependable in operation.

Summary of the invention In accordance with the invention, an electric circuitl breaker operating mechanism is provided including at least one stationary contact member and at least one moveable contact member and spring means acting between the movable contact member and a normally stationary support member to provide contact closing pressure. Upon the occurrence of predetermined conditions, the stationary support member is released, and the operating spring acts on the stationary support member to impart motion thereto in a direction away from the stationary contact, thereby storing kinetic energy in the support member and its associated parts. This kinetic energy is utilized, by means of a lost motion connection lwith the movable contact member, to move the movable contact member in open circuit direction, the parts being latched open, pending subsequent manual reclosing operation.

The invention will be more fully understood from the 'lfollowing detailed. description, and its scope will be pointed out in the appended claims.

-Brief description of the drawings In the drawings,

FIGURE 1 is a side elevation view of a circuit breaker operating mechanism incorporating the invention, the supporting and enclosing insulating casing being shown only fragmentarily for clarity;

FIGURES 2 through 5 are semi-schematic representations of the mechanism of FIGURE 1, the parts being shown in the following conditions:

FIGURE 2-c1osed circuit condition;

FIGURE 3-just subsequent to tripping initiation and prior to separation of the contacts;

FIGURE 4-following trip initiation and after opening of the contacts, but prior to completion of the automatic opening movement;

FIGURE S-normal open or tripped condition;

FIGURE 6 is a side elevation view of another embodiment of the invention, comprising a resettable cut-out or non-trip-free circuit breaker.

Description of the illustrated embodiment In the drawings, the invention has been shown in FIG- URE 1, as incorporated in an electric circuit breaker of the general type shown and described in prior Patent 3,158,711, B. A. Piteo, Nov. 24, 1964, assigned to the same assignee as the present invention. The parts illustrated are supported and insulated by suitable insulating casing means, shown only fragmentarily. The circuit breaker illustrated includes an in-coming or load terminal 1, having an elongated conductor 2 connected thereto, leading to an angular combined stationary contact and support member 10 spaced closely from a correspondingly shaped cooperating combined stationary contact support and arc runner member 11 which is connected by conductor 3 to a solenoid coil 4 having its other end connected to a line terminal 5.

The contact support members 10 and 11 include stationary contacts 12 and 13 respectively which are contacted by movable contacts 14 and 15 carried by a movable bridging contact member 16. When the bridging contact member 16 is moved upwardly, it carried 'with it the movable contacts 14 and 15, separating them from theY into a single arc which exists subsequently directly between the runner portions A and 11A of the contact support assemblies 10 and 11, moving outwardly therealong and becoming elongated and finally extinguished.

For the purpose of moving the bridging contact assembly -16 between open and closed circuit positions both manually and automatically, operating mechanism is provided in accordance with the invention including a pair of toggle links 17 and 19 interconnected by a toggle knee pivot pin 18. The upper toggle link 19 is pivotally connected by a pivot pin 20 to a manually operable closing button member 21.

The manual closing member 21 includes a latch portion 22 which is adapted to be releasably held by a latch member 23 pivotally supported at 24 in the insulating casing, not shown. The latch member 23 is generally L- shaped and includes an extending portion 23A, which is biased by a compression spring 24 against a stop portion 25 of the casing.

|For the purpose of operating the latch member 23 to release the manual member 21, an off button 26 is provided, having a stem 27 projecting downwardly and having its end portion adjacent the extension 23A of the latch member 23. A compression spring 28 is further provided, biasing the 01T button toward its unactuated position, i.e., upwardly, at all times.

The upper toggle link 19 includes an offset extension 29 extending beyond the pivot pin 20 and having a portion adapted to engage a pin 30 carried by -the latch member 23 on the occurrence of predetermined current conditions, and for a purpose to be described.

The movable contact assembly 16 includes a stem portion 16A terminating in a generally disc-shaped upper portion 16B. The disc-shaped portion 16B moves slidably within a generally cup-shaped member 32, shown in section for purposes of clarity, which includes an integral extension 32A connected by means of a pivot pin 33 to the lower toggle link 17.

The main operating compression spring 34 is trapped within the cup-shaped member 32 `and acts between the cup-shaped member 32 and the disc-shaped portion 16B of the movable contact member. The cup-shaped member 32 includes an inwardly directed flange portion 32B which is bent-over after assembly of the parts therein to retain the disc-shaped portion 16B and the operating spring 34 therein. The cup-shaped member 32 is guided for sliding reciprocating movement by means of insulating guide formations 32C in the insulating casing. The guide portions 32C also include extensions 32C' and a wall 32D which serve to restrain the arc products generated by separation of the contacts, to the immediate area between the stationary contacts 12 and 13. The solenoid 4 includes an armature member 4A Iwhich is slidably guided within a suitable cylindrical non-magnetic guide member 4B. The armature 4A is provided with a rigid extending arm 40 terminating in a hook portion 41 adjacent the knee pin 18 of the toggle linkage 17, 19. The toggle linkage 17, 19 also includes a wire type spring 38 acting on the knee pivot 18 to constantly bias the toggle linkage 17, 19, to straightened condition.

OPERATION Manual operation Assuming the parts to be in the condition illustrated in FIGURE 1 and schematically in FIGURE 2, manual opening of the contacts is achieved by depressing the off button 26, which causes the rod 28 to act on the latch member 23, rotating it counterclockwise against the bias of spring 24' to withdraw the latch 23 from the latch projection 22 of the manual closing member 21.

It will be observed that in the on condition of the parts as shown in FIGURES 1 and 2, the operating compression spring 34 is acting against the back wall of the member 32 on one hand and the disc-shaped portion 16B of the movable contact assembly 16 on the other. Since the toggle linkage is in its set condition, and is latched by the latch 23, the spring 34 has a normally stationary support for one end thereof, the other end acting against the movable contact member to produce contact closing pressure.

Upon the release of the latch member 23, however, the compression spring 34 expands, moving the member 32 and the toggle linkage 17, 19, together with the manually operable member 21 upwardly as viewed in FIGURE l. As this motion proceeds, kinetic energy is built up in the movable members comprising the member 32, and the toggle links 17, 19, and the manually operable member 21.

When the lost motion between the parts 16B and 32B is taken up, the momentum of the parts 32 and the links 17 and 19 in the upward direction pulls the movable contact assembly 16 upwardly to open condition as indicated diagrammatically in FIG. 5. In this position, the resilient hook 21A engages the flange of the manual closing button 21 and holds -the parts in the open condition.

Operation-Automatic tripping Assuming the parts to be in the condition shown in FIGURE 1, if the current through the circuit breaker exceeds a predetermined amount, the pull exerted by the solenoid 4 on its armature 4A, and through the link 40 on the pin 18, becomes sul'licient to collapse the toggle linkage 17, 19 to the right as indicated in FIG- URlE 3. This releases the compression spring 34, which throws the spring actuating member 32 upwardly, with the result that its velocity and momentum are suicient to carry the movable contact member 16, after the lost motion has been taken up between the members 32 and 16, upwardly, to open circuit position. At the same time, the tilting of the upper toggle link 19 also has the effect of releasing the latch member 23. This occurs because of the action of the projection 29 on the pin 30, rotating the latch member 23 in counterclockwise direction and disengaging it from the latch.

The buckling of the toggle linkage 17, 19 and the release of the latch 22 occurs simultaneously, leaving this assembly free to be moved upwardly by the action of the compression spring 34. The parts, therefore, comprising the support member 32, the toggle links 17 and 19, and the operating button 21, are all thrown rapidly upward upon buckling of the toggle linkage, and given an upwardly directed momentum. When the lost motion between the members 32 and 16B is taken, up, the movable contact member 16 is moved upwardly in open circuit direction interrupting the current and releasing the armature 4A of the solenoid 4. The spring 38 thereupon acts to straighten the linkage 17, 19, and the parts assume their full open position as shown in FIGURE 5 in which the surface 22 `of the support member 22 overlies the upper edge of the latch member 23, maintaining the parts in open circuit position as indicated schematically in FIGURE 5.

The form shown in FIGURE 6 comprises a simplied, non-trip-free circuit breaker operating on the same principle as the form of FIGURE 1.

In this form, a bridging contact 16' is held in closed position by a spring 34 acting on the rod 16A. The spring 34 is kept compressed by a rigid push rod 50 having a detent 50A receiving a latch member 51. The latch member 51 is biased by a spring 27 to latching position and includes a portion 51A serving as an armature for solenoid 4 connected in series with the contacts.

Upon the release of latch 51 by means of the manual button 26 or by the solenoid 4', the spring 34 is freed to -begin upward movement of the rod 50, member 32 and button 21, throwing these parts upward. When the lostmotion between |32 and 16B is taken up, the rod 16A and contacts 14 and 15' are moved to open position. When the rod 50 moves upwardly, the spring latch 23 drops into the detent 50B and holds the parts in open condition. To reclose, the button 21 is depressed, causing the spring latch 23 to deflect sideways until the latch 23 slides out of the detent 50B and the contact assembly is moved to the closed position shown.

While the invention has been shown as incorporated in two specic forms, it will be readily apparent that many modiiications thereof may readily be made. Thus current-responsive means may be applied to latch 23 in the FIGURE 1 form to provide automatic opening rather than solenoid 4. It is therefore intended by the attached claims, to cover all such modifications as come within the true spirit and scope of the invention.

What =I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric circuit breaker comprising:

(a) a support;

(b) at least one stationary contact supported on said support;

(c) at least one movable contact supported on said support for movement between open and closed circuit positions with respect to said stationary contact;

(d) an actuating member supported on said support;

(e) spring means having one end thereof acting on said movable contact member and having the other end thereof acting on said actuating member;

(f) lost-motion connecting means connecting said actuating member and said movable contact member;

(g) operating means carried by said support for moving said actuating member to a first position in which said spring means is stressed so as to urge said movable contact toward said closed circuit position;

(h) releasable means carried by said support for restraining said actuating means in said first position;

(i) current responsive means carried 4by said support for causing release of said releasable means upon the occurrence of predetermined current conditions in said circuit breaker;

(j) latch means for latching said movable contact in open-circuit position;

(k) the inertia of said actuating member and said operating means following release of said releasable means being such that following take-up of said lost-motion in said connecting means between said spring-operating member and said movable contact member, said inertia causes said actuating member to move said movable contact member in open circuit direction and into latched engagement with said latch means.

2. An electric circuit breaker as set forth in claim 1 wherein said circuit breaker comprises a pair of spaced stationary contacts supported on said support and wherein said movable contact member comprises a bridging conductive member interconnecting said stationary contacts when in said closed circuit position.

3. A-n electric circuit breaker as set forth in claim 1 wherein said operating means for operating said actuating member comprises a pair of interconnected toggle links and releasable supporting means for supporting one end of said toggle links, the other end of said toggle links being connected to said actuating member, and means releasably restraining said toggle links in straightened condition.

14. An electric circuit breaker as set forth in claim 1 wherein:

(a) said spring means comprises a compression spring,

and wherein (b) said actuating member comprises a generally cupshaped cylindrical member receiving said compression spring therein; and

(c) a generally disc-shaped member slidably received within said cup-shaped member and acting on said compression spring means, and

(d) means interconnecting said movable contact member and said generally disc-shaped member.

5. An electric circuit breaker as set forth in claim 4, said circuit breaker also including an electric solenoid connected electrically in series with said contacts, said solenoid including an armature member and means connecting said armature member to said toggle linkage for collapsing said toggle linkage upon the occurrence of predetermined current conditions through said solenoid.

References Cited UNITED STATES PATENTS 2,184,372 12/1939 Von Hoorn 335--16-9 2,701,284- 2/ 1955 Edmunds 335-167 3,158,711 11/1964 Pitco 335--173 BERNARD A. GILHEANY, Primary Examiner. HAROLD BROOME, Assistant Examiner.

U.S. Cl. X.R.

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