US2297320A

US2297320A - Circuit breaker

Info

Publication number: US2297320A
Application number: US392603A
Authority: US
Inventors: Elwood T Platz
Original assignee: Bulldog Electric Products Co
Current assignee: Bulldog Electric Products Co
Priority date: 1941-05-09
Filing date: 1941-05-09
Publication date: 1942-09-29
Anticipated expiration: 1959-09-29

Description

p 1942. E. T. PLATZ 2,297,320

CIRCUIT BREAKER Filed May 9, 1941 3 Sheets-Shqet 1 Sept. 29, 1942. E. "r. PLATZ CIRCUIT BREAKER Filed May 9, 1941 3 Sheets-Sheet 2 /////////////I/II// TQ/PPED f 2615 INVENTOR KQuM M Sept. 29, .1942. E. r. PLATZ 2,297,320

CIRCUIT BREAKER Filed lay 9, 1941 3 Sheets-Sheet 3 Patented Sept. 29, 1942 UNITED STATES PATENT OFFlCE.

' azamzo cmcm'r BREAKER Elwood 'r. Plats, Detroit, Mich, assignor to Bulldog Electric Products Company, Detroit, Mich a corporation of West Virginia Application May 9, 1941, Serial No. 392,603

2 Claims. (01. 200-116) This application relates to circuit breakers and, in one aspect, relates to multipole circuit breakers.

One object of the invention is to provide a multipole circuit breaker all of whose poles will open on the arising of an overload in any pole. In one form of the invention all of the poles open simultaneously: In another form the pole in which the overload occurred would open first and cause the opening of the other poles.

Another object of the invention is to provide a multipole circuit breaker embodying certain features of circuit breaker construction, such as a rocker handle, a single spring on each pole for maintaining contact pressure and for pro-, viding a tripping force, trip free operation, etc.

Another object is to provide a circuit breaker wherein a contact arm holding element is utilized as an operative connection between the contact arm and the handle.

A preferred embodiment of the invention is .In these shown in the appending drawings. drawings,

Figures 1 to 3 are section views of the device, along line |-I of Figure 5, in three diflerent positions, as indicated.

Figure 4 is a section on line 4-, Figure .5.

Figures 5 and 6 are top and bottom plan views,

. respectively.

Referring to the drawings it will be seen that these show a circuit breaker casing having a major compartment land a minor compartment Barriers |2 help to divide the major compartment into three cells, each containing a contact arm or bar H having a movable contact I5 for engaging a stationary contact IS. The barriers |2 thus isolate the diflerent poles, a desirable feature. Each arm has an axle or pin ll whose ends ride in slots l8 formed in the cell walls to permit rocking of the contact arms in paths determined by the guiding portions I! formed on the cell walls.

post at stationary contact IE to the binding post at bracket 21 through a contact bar H, a connector 25, and a warping element 26.

Fixed to the cross shaft 24 and disposed within the cells containing the contact bars It are arms II to which are connected ends of springs 32 in turn connected to the contact bars l4.

Disposed within the minor compartment H and fixed to cross shaft 24 which thus journal them, are a rocker handle 33 and an arm 34, whose free end is operatively connected to the casing by a suitable overcenter or snap spring arrangement 35.

The operation of the breaker is as follows: Manual switching action is obtainedby movement of the rocker handle, the first part of each stroke being opposed by the overcenter means 25 and the latter part of each stroke being aided by such means 35 for typical snap action. Handle movement will cause rotation of the cross shaft 24 and of the arms 23 and 3|. Movement of arms 23 will cause rocking of the contact arms on their pivots H by virtue of the operating con nection between the arms 23 and contact arms ll established through the latch bars 2|. The

floating of the axles H in slots l8 will permit End lugs 20 o! the arms or bars releasably interlock with slots of latching or holding bars 2| fixed to a transversely extending common trip bar or shaft 22 rotatably mounted or journaled at its ends in arms 23 fixed to a cross shaft 24 in turn journaled in the sides of the casing. A flexible connector 25 connects each bar H with a bi-metal warping element 26 anchored to a bracket 21 supporting a U shaped magnet 28 surrounding the element 28 and cooperating with the metal latch bar 2| to form a magnetic loop around the bi-metal element 26. The circuit for contact pressure for all contact arms to be equalized while maintained independently by springs 32. These springs also provide tripping force to move the arms |l counterclockwise on their axles free of the handle, when the arms are released by the latch bars 2|, incident to overload.

The magnetic loop 282| around each warping element 26 provides for quick opening in the event of a short circuit and accelerates opening of the circuits on ordinary overloads.

When an overload or short circuit occurs in any pole thelatching bar 2| of that pole is moved counterclockwise to release its arm It so that it will be tripped by its spring 32. To permit such movement of bars 2|, the common trip shaft 22 is journaled in the arms 23, though normally springs (not shown) maintain shaft 22 in the position indicated in Figure 1 with latch bars 2i engaging contactarms ll, these springs (not shown) being overcome on overload by the forces which move the latch bars each pole is thus established from the binding 2| counterclockwise, either the warping of the elements 26 or the magnetic forces of the magnetic loops 28--2|.

It will thus be observed that springs 32 have many functions: they aid circuit opening movement or bars l4 responsive to handle actuation; they cause overload opening movement or bars it without opposing circuit closing movement; and they also maintain and equalize contact pressure.

For resetting all poles subsequently to an overload release of all poles, it is merely necessary to move the handle from the position of Figure 3 to that of Figure 2 so that the lower ends of the latch bars 2! pick up and re-engage the elevated right ends of the contact arms It, the parts assuming the open circuit position of Figure 2- Now having described the circuit breaker herein disclosed, reference is now made to the claims winch follow.

1 claim:

1. In a circuit breaker, a movable contact bar having at one point a contact for engaging a stationary contact, holding means releasably engaging another point on the bar, spring means between the contact and the holding means for normally biasing the her contact against the stationary contact, when the holding means holds, and for normally biasing the bar against the holding means so as to be held thereby, means forming a fixed Journal for the bar at a point between the spring means and the contact'thereof whereby the spring means rocks the bar for contact separation when the holding means releases the bar, and manual actuation means including a fulcrummed' lever separate and independent of the bar journal means and connected to the holding means for moving it, and for moving the bar when the holding means holds the bar, onthe bar Journal point as a pivot, for eil'ecting contact separation, when the manual actuation means is moved .in one direction, the manual actuation means also functioning, when moved in the opposite direction, to ret the bar to the stationary contact, the fulcrum of the lever and the journal of the bar being relatively spaced so that the axes of rotation of lever and connected at one point of the bar, the aforesaid enemas two points, with the lever fulcrum and the bar journal, defining a parallelogram, whereby the spring means is not stressed during manual actuation movement.

2. In a circuit breaker, a movable contact her having at one point a contact for engaging a stationary contact, holding means releasably engaging another point on the bar, spring means between the contact and the holding means for normally biasing the bar contact against the stationary contact, when the holding means means forming a fixed journal for the bar at a mint between the spring means and the contact thereof whereby the spring means rocks the I bar for contact separation when the holding all means releases the bar, and manual actuation means including a fulcrummed lever separate and independent of the bar journal means and connected to the holding means for moving it, and for moving the bar when the holding means holds the bar, on the bar journal point as a pivot, for efiecting contact separation, when the manual actuation means is moved in one direction, the manual actuation means also functioning, when moved in the opposite direction, to return the bar to the stationary contact, the fulcrum of the lever and the Journal of the her being relatively spaced so that the axes of rotation of lever and bar are eccentric, and circuit responsive means for moving the holding means, on overload, away from the bar to release it, the l'ever'and bar rotating in parallel planes, said spring means and lever being interconnected at one point of the lever, said spring means and her being interconnected at one point of the bar, the aforesaid two points, with the lever fulcrum and the bar journal, defining a parallelogram,

whereby the spring means is not stressed during manual actuation movement, the fulcrum of the lever and the interconnection of the lever and the strip being formed as parallel shafts transverse of the lever and bar and of their planes of rotation, and a handle connected to the lever fulcrum shaft.