US2274135A

US2274135A - Circuit breaker

Info

Publication number: US2274135A
Application number: US302980A
Authority: US
Inventors: William H Frank; Joseph A Messing
Original assignee: Bulldog Electric Products Co
Current assignee: Bulldog Electric Products Co
Priority date: 1939-11-06
Filing date: 1939-11-06
Publication date: 1942-02-24
Anticipated expiration: 1959-02-24

Description

Feb. 24, 1942. w. H. FRANK ETAL 2,274,135

CIRCUIT BREAKER Filed Nov. 6, 1939 2 Sheets-Sheet l AUTOMATIC RESET n it NO AUTOMATIC 7 31 RESET l7 INVENTORLS AIM I 1-4 zfd M ZTORNEY.

- Feb. 24, 1942.

W. H. FRANK EIAL CIRCUIT BREAKER Filed Nov. '6, 1939 2 Sheets-Sheet 2 I than;

a eWa'i-b. 24, 1942 CIRCUIT BREAKER William H. Frank and Joseph A. Messing, Detroit, Mich., assignors to Bulldog Electric Products Company, Detroit, Mich., a corporation of West Virginia Application November 6, 1939, Serial No. 302,980

15 Claims.

This application relates to circuit controlling means or circuit breakers and is a continuation in part of our application Serial No, 99,265 filed September 3, 1936, which in turn discloses an improvement over the breaker shown in Patent No. 2,072,163 of March 2, 1937. Application Serial No. 99,265 filed September 3, 1936, became Patent No. 2,251,703 on August 5, 1941.

In that application there is shown an overload release circuit breaker having an automatic reclosing action and a manually accessible control means for providing manual switching action for the breaker.

The control means of that application is so constructed as to lack a quick make and break manual latch may be te m uum ne vent automatic reclosing without at the same time causing release. The means may be oper-,

ated to set the parts in such a condition that fol-1 0 lowing an overload release opening of the breaki er, the parts move to an open circuit position: from which they can be moved manually into the closed circuit position.

The breaker hereof, as well as the breaker shown in the parent application, Serial No. 99,265 above mentioned, has as a feature the use of a magnet operating directly on the contact for biasing it to open circuit position, in opposition to the spring which tends to bias it into the closed circuit position, the magnetic force operating to open the circuit, not through any manual operation means, nor through any overload release latch means, but directly on the contact in an operating path independent of any manual operation means and independent of any overload release latch means.

The control means distinguishing the breaker hereof from that of the prior application, Serial No. 99,265, when operated to prevent automatic reclosing, merely shifts the line of action of the spring which causes closing so that that spring can not operate to cause closing, once the parts have moved to open circuit position on overload, but the control does not operat to cause release of the parts when it is moved to prevent automatic closing of the parts.

For an understanding of the circuit breaker embodiment herein disclosed, reference should be had to the appended drawings showing a circuit breaker of the automatic release and reclosing type having a manual control means for the breaker which is of the spring snap action type and which is operable for preventing automatic closing without such operation causing release. In the drawings. wherein the parts are shown diagrammatically:

Figs. 1 and 4 show the breaker in on and tripped positions respectively, but with the control means in a position to permit automatic reclosing following release;

Fig. 2 shows the breaker in on" position, but with the control means in such a position as to prevent automatic reclosing and to require a manual movement for a closing following release;

Fig. 3 shows the breaker in 011" position;

Fig. 4a is a fragmentary plan view of Fig. 1.

Figs. 5 and 6 show alternate wiring diagrams for the breaker.

The drawings show a circuit breaker employing a solenoid l0 whose plunger l l is connected through a link l2 to a breaker contact arm H! by a pin and slot connection at IS. The solenoid 10, the arm I, and the overload release element l9 are electrically connected as shown in Figs. v5-6. The operation of the magnet is under the time delay control of the element l9, provided by the contacts 50 (Fig. 6) closed on warping of element ill on overload due to the coil 5|, or provided by the latch It on the link I 2 which is normally caught under a cross piece ll, restrained against movement to the right for release of link l2 by the tip l8 of the element l9. Pedestals 20 and it support the contact arm 14 and the cross piece IT.

The cross piece is formed with a slot 30 formed to cooperate with the latch 16 pivotally mounted n the link l2 and urged by a spring 3| to assume he position shown, with the latch engaging the stop 32 formed on the link l2, the latch being movable in opposition to the spring 3| from the position shown, in a counterclockwise direction.

The curved end 33 of the contact arm II is connected at 34 to a tension spring 35 which in turn is connected at 36 to the handle 31 pivotally mounted at 38 on pedestal 20. Movement of the handle 31 left and right to and from the positions of Figs. 1 and 3 causes the spring 35 to cross the center or pivot 38 and thus to swing the contact arm H open or closed with a spring snap action.

An indexing plate 39 (Fig. 4a) having three teeth, the extreme two of which are occupied by the handle 31 in the positions of Figs. 1 and 3 and the intermediate one of which determines the position of the handle in Fig. 2 is provided.

The various operations of the breaker and its functions are as follows:

When the contact arm 14 is in closed position, Figs. 1 and 2, the remaining parts are in the positions of Figs. 1 or 2. Spring 35, now to the left of pivot 38, holds the contact arm in closed position with a spring pressure for butt contact.

Movement of handle 31 to the left (Fig.3) causes the spring to cross pivot 38 and this snaps arm H up to open the circuit, the lost motion at l5 acting to permit the contact arm to move without moving link I2. Reverse movement of the handle (to Fig. 1) causes the arm to move down with a snap action to close the circuit.

If an overload occurs, solenoid i is energized and tends to pull arm l4 upwardly to open the circuit. Nothing will happen, however, unless the overload has endured suificiently long to warp element l9 so that it will move cross piece 11 to the right or close contacts 50 to permit the parts l||2l4 to move upwardly and open the circuit.

The pin and slot connection l insures opening of the circuit in the event of sticking of the contacts by providing suffici-ent momentum of link l2 before it meets the resistance offered by contact arm H on solenoid pull.

Automatic overload release action will take place if the breaker be closed, regardless of the position of the handle 31, as can readily be seen, inasmuch as such action does not depend upon the position or operation of the spring 35.

Reclosing will take place automatically (in the event the handle is in the position of Fig. 1 when an overload release occurs), following overload release, and after a delay provided by the cooling of element I9 (long enough to insure opening of contacts 50 or slot of cross piece l1 returning to the position of Fig. 1, wherein it permits latch l6 and link l2 to move down) by virtue of the spring tension of spring 35, which is still to the left of pivot 38, not having moved overcenter during overload release.

For preventing an automatic reclosing subsequent to an automatic release, handle 31 may be moved to the position of Fig. 2. This movement does not cause opening of the circuit breaker but merely sets the parts in such a position that in the event the circuit breaker opens on an overload, it will not close automatically but will require manual movement for closing. When the handle 31 is put in the position of Fig. 2, the line of action of spring 33 is placed very close to pivot 38, and this renders the spring 35 inoperative to pull down the contact arm it after it had been moved to open position on an automatic or overload release; with handle 31 in the position of Fig. 2, there is nothing to prevent the arm I 4 from being moved upwardly by the solenoid.

During the overload release operation, spring 35 crosses overcenter to move handle 31 to the open circuit position of Fig. 3, where the parts remain, automatically set in such open position by the overload release and by the placing of the handle prior to such release in the position of Fig. 2.

Note here that the breaker is a normally closed spring held breaker which may be opened by the application of a force (magnet) on the arising of an overload. In the on" position, arm M is normally biased into closed position; the handle may move the arm with a snap action to open and closed positions, through the overcenter action of the spring 35. The breaker automaticaly opens on an overload completely trip free of the handle.

We claim:

1. In an automatic opening and reclosing circuit breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including a handle and a spring for moving the movable contact with a spring snap action to and from the stationary contact in response to movements of the handle and arranged to hold the movable contact against the stationary contact when the handle is in circuit closed position and to tend to move the movable contact towards the stationary contact in the event the movable contact is remote from the stationary contact and the handle is in circuit closed position, and overload responsive means automatically operable on overload for overcoming the spring and moving the movable contact away from the stationary contact, and for thereafter releasing the movable contact so that the spring can return it automatically to the stationary contact.

2. In an automatically opening and reclosing circuit breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including a handle and a spring for moving the movable contact with a spring snap action to and from the stationary contact in response to movements of the handle and arranged to hold the movable contact against the stationary contact when the handle is in circuit closed position and to tend to move the movable contact towards the stationary contact in the event the movable contact is remote from the stationary contact and the handle is in circuit closed position, and overload responsive means separate and independent of the first named means and automatically operable on overload for overcoming the spring and moving the movable contact away from the stationary contact, and for thereafter releasing the movable contact so that the spring can return it automatically to the stationary contact.

3. In an automatic opening and reclosing circuit breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including a handle and a spring for moving the movable contact with a spring snap action to and from the stationary contact in response to movements of the handle and arranged to hold the movable contact against the stationary contact when the handle is in circuit closed position and to tend to move the movable contact towards the stationary contact in the event the movable contact is remote from the stationary contact and the handle is in circuit closed position, and overload responsive means automatically operable on overload for overcoming the spring and moving the movable contact away from the stationary contact, and for thereafter, following a time delay, releasing the movable contact so that the spring can return it automatically to the stationary contact.

4. In an automatic opening circuit breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including a handle and a spring for moving the movable contact with a spring snap action to and from the stationary contact in response to movements of the handle and arranged to hold the movable contact against the stationary contact when the handle is in circuit closed position and to tend to move the movable contact towards the staionary contact in the event the movable contact is remote from the stationary contact and the handle is in circuit closed position, and overload responsive means automatically operable on overload for overcoming the spring and moving the movable contact away from the stationary contact without moving the handle from closed circuit position, and for thereafter releasing the movable contact so that the spring can return it automatically to the stationary contact, the handle and spring being movable manually to a position wherein the spring is rendered incapable of exerting any stress on the movable contact after automatic opening operation, whereby there will not be an automatic reclosing after an overload opening.

5. In an automatic opening circuit breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including a handle and a spring for moving the movable contact with aspring snap action to and from the stationary contact in response to movements of .the handle and arranged to hold the movable contact against the stationary contact when the handle is in circuit closed position and to tend to move the movable contact towards the stationary contact in the event the movable contact is remote from the stationary contact and the handle is in circuit closed position, and overload responsive means automatically operable on overload for overcoming the spring and moving the movable contact away from the stationary contact without moving the handle from closed circuit position, and for thereafter releasing the spring snap action to and from the stationary contact in response to movements of the handle and arranged to hold .the movable contact against the stationary contact when the handle is in closed circuit position, electrically operating overload actuating means separate and independent of the tlrst named means and automatically operable when released on an overload by a holding means for overcoming the spring and moving the movable contact away from the stationary contact even though the handle be held in closed circuit position and holding means for said actuating means, arranged to release the latter on overload.

8. In a circuit breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including 'a handle and a spring movable contact so thatv the spring can return it automatically to the stationary contact, the

handle and spring being movable manually to aposition wherein the spring is rendered incapable of exerting any stress on the movable contact after automatic opening operation, whereby there will not be an automatic reclosing after an overload opening, with the parts so arranged that such movement of the handle and spring means does not cause the movable contact to move away from the stationary contact but-merelyprevents the movable contact from returning to the stationary contact in the event the movable contact is caused-to leave the stationary contact, as on overload, by the action of the overload opening means.

6. In a circuit-breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including a handle and a spring for moving the movable contact with a spring snap action to and from the stationary contact in response to movements otthe handle and arranged to hold the movable contact against the stationary contact when the handle is in closed circuit position, electrically operating overload actuating means separate and independent of the first named means and automatically operable when released on an overload by a holding means for overcoming the spring and moving the movable contact away from the stationary contact and holding means for said actuating means, arranged to release the latter on overload.

'7. In a circuit breaker, a stationary contact, a movable contact,.a manually operable overcenter spring means including a'handle and a spring for moving the movable contact with a for moving the movable contact with a spring snap action to' and from the stationary contact in response to movements of the handle and arranged to hold the movable contact against the stationary contact when the handle is in closed circuit position, electrically operating overload actuating means separate and independent of the first named means and automatically operable when released on an overload by a holding means for overcoming the spring and moving the movable contact away from the stationary contact and thereafter'releasing the contact to the influence of the spring, whereby the spring will automatically reclose the circuit and holding means for said actuating means, arranged to release the latter on overload.

9. In a circuit breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including a handle and a spring for moving the movable contact with a spring snap action to and from the stationary contact in response to movements of the handle and arranged to hold the movable contact against .the stationary contact when the handle is in closed circuit position, electrically operating overload actuating means separate and independent of the first named means and automatically operable when released on an overload by a holding means for overcoming the spring and moving the movable contact away from the stationary contact and thereafter releasing the contact to the influence of the spring; whereby the spring will automatically reclose the circuit, and holding means for said actuating means, arranged to release the latter on overload, the handle being movable manually to a position wherein the spring can not move the movable contact back to closed circuit position after it is moved to the open circuit position by the actuating means following its release by the holding means.

10. In a circuit breaker, a stationary contact, a movable contact, amanually operable overcenter spring means including a handle and a spring for moving the movable contact with a spring snap action to and from the stationary contact in response to movements of the handle and arranged to hold the movable contact against the stationary contact whenthe handle is in closed circuit position, electrically operating overload actuating means separate and independent of the first named means and automaticall operable when released on an overload by a holding means for overcoming the spring and moving the movable contact away from the stationary contact, and holding means for said actuating means, arranged to release .the latter on overload there being a time delay provision for the operation or the actuating means.

11. In a circuit breaker, a movable contact, means for automatically causing opening and reclosing movements thereof cyclically, a quick make and break, snap action, manually operable means for manually moving the contact to open and clase the circuit, and constructed to be operable for inhibiting automatic reclosing operation of the first means without causing circuit opening movement of the contact.

12. In a circuit breaker, a movable contact, means for automatically causing opening and reclosing movements thereof cyclically, a quick make and break, snap action, overcenter spring, manually operable means for manually moving the contact to open and close the circuit, and constructed to be operable for inhibiting automatic reclosing operation oi the first means without causing circuit opening movement of the contact.

13. In an automatic opening circuit breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including a handle and a spring for moving the movable contact with a spring snap action to and from the stationary contact in response. to movements of the handle and arranged to hold the movable contact against the stationary contact when the handle is in circuit closed position and to tend to move the movable contact towards the stationary contact in the event the movable contact is remote from the stationary contact and the handle is in circuit closed position, and overload responsive means automatically operable on overload for overcoming the spring and moving the movable contact away from the stationary contact without moving the handle Irom closed circuit position, and for thereafter releasing the movable contact so that the spring can return it automatically to the stationary contact, the handle and spring being movable manually to a position wherein the spring is rendered incapable of exerting any stress on the movable contact after automatic opening operation, whereby there will not be an automatic reclosing after an overload opening, the parts being so arranged that when the handle is in a position to prevent automatic reclosing, and an overload arises, the handle is moved to the open circuit position into which it is ordinarily moved on manual operation, and all parts come to rest in an open circuit position.

14. In an automatic opening circuit breaker,

2,274,185 I tionary contact and the handle is in circuit closed position, and overload responsive means automatically operable on overload for overcoming the spring and moving the movable contact away from the stationary contact without moving the handle from closed circuit position, and for thereafter releasing the movable contact so that the spring can return it automatically to th stationary contact, the handle and spring being movable manually to a position wherein the spring is rendered incapable of exerting any stress on the movable contact after automatic opening operation, whereby there will not be an automatic reclosing after an overload opening, with the parts so arranged that such movement of the handle and spring means does not cause the movable contact to move away from the stationary contact but merely prevents the movable contact from returning to the stationary contact in the event the movable contact is caused to leave the stationary contact, as on overload, by the action of the overload opening means, the parts being so arranged that when the handle is in a position to prevent automatic reclosing, and an overload arises, the handle is moved to the open circuit position into which it is ordinarily moved on manual operation, and all parts come to rest; in an open circuit position.

15. In a circuit breaker, a stationary contact, a movable contact, a manually operable overcenter spring means including a handle and a spring for moving the movable contact with a spring snap action to and from the stationary contact in response to movements of the handle and arranged to hold the movable contact against the stationary contact when the handle is in closed circuit position, electrically operating overload actuating means separate and independent of the first named means and automatically operable when released on an overload by a holding means for overcoming the spring and moving the movable contact away from the stationary contact and thereafter releasing the contact to the influence o! the spring, whereby the spring will automatically reclose the circuit, and holding means for said actuating means, arranged to release the latter on overload, the handle being movable manually to a position wherein the spring can not move the movable contact back to closed circuit position after it is moved to the open circuit position by the actuating means iollcwing its release by the holding means, the parts being so arranged that when the'handle is in a position to prevent automatic reclosing, and an overload arises, the handle is moved to the open circuit position into which it is ordinarly moved on manual operation, and all parts come to rest in an open circuit position.

WILLIAM H. FRANK. JOSEPH A. MESSING.