US2551397A

US2551397A - Electric circuit breaker

Info

Publication number: US2551397A
Application number: US63577A
Authority: US
Inventors: Raymond N Rowe
Original assignee: Trumbull Electric Manufacturing Co
Current assignee: Trumbull Electric Manufacturing Co
Priority date: 1948-12-04
Filing date: 1948-12-04
Publication date: 1951-05-01
Anticipated expiration: 1968-05-01

Description

y 1951 R. N. ROWE ELECTRIC CIRCUIT BREAKER Filed Dec. 4, 1948 Fgl.

M L h ll m v Fig.7

FT Inventor: 39 Raymond N Rowe l M ETAL INSULATION Patented May 1, 1951 The Trumbull 'Electric -Manu'facturing "Company, 'Blainv'ille, Conn a corporation of Con- 'necticut Application December 4, r1948,-.Serial No. 63,577

13 Claims. 1

JMy invention relates "to switches or circuit breakers actuated manually to open and close a circuit and automatically to .open a circuit on an overload in the :circuit and manually resettable after automatic release.

Such'switches utilize :atoggle action for swinging the movable contact when opening and clos ing the circuit.

One object is to "improve the e'iiectiveness "of the makeand breakactio'n.

Anotherobj ect is to simplify the construction.

Another object. is "to slide the movable contact across the face .of the stationary contact when the circuit is broken automatically, to prevent sticking.

Another object is to provide a 'mechanism where two or more breaker units are independently operable and in which the automatic tripping of any one unit maybe initiated unhindered by the other units-and'yet in which all units will trip automatically whenany one trips.

The current responsive elementin each unit is only called upon to furnish sufficient force for tripping that particular unit. Thereafter the main operating spring of the circuit breaker mechanism .comes .into play to cause tripping of the adjacent unit or units.

Another object 'is .to provide a multiple un'it breaker in which each unit maybe independently calibrated and yet the tripping or any one "unit upon "an overload will cause the other unit or units to be tripped automatically regardless of the condition of the overloaddevices of the other units.

Fig. '1 is a plan view showing a combinationof two units involving my invention, parts being broken away.

Fig. 2 is an end View of the exterior of the switch of. Fig. 1.

Fig. 3 is a longitudinal sectional view taken on ltheplane of the line 3-3 of Fig. -1, the parts being shown in the closed circuit position.

Fig. 4 a cross-tsectionalview taken -.on the plane-of the line'44=of:Fig. 3.

Fig. 5 is a fragmentary sectional view :similar to 355g. 3 but showing the .Darts sin theopen'circuitposition. v

Fig. 6 is another view similar to Figs..:3 .and 5 but with the parts in .the opencircuitposition after automatic tripping.

Fig. .7 :is .a .detail plan of the overload release actuator.

Fig. Bis aside viewo'f the;rocker .ortrip mem- 'ber.

'Fig. 91s a detail plan of the'latch member.

Each unit of the invention isshown :a-s .embodiedinan insulating housing having a-base 410 and .a cover 11. A stationary contact 1.2 inside the housing has an external terminal .I3. The

other terminal I4 is connected to the movable switch contact. armniember !.5 .by a thermostatic :bimetal overload strip i6 .and flexible conductors i1 and 48.

All of the switch parts except the stationary contact l2 are carried by a. U-shaped .frame .20. The rocker or trip member 2101? insulating vinaterial is pivoted at 22 in theirame. The actuating slever.23 is pivoted at 24 and has a-handle 25 which may "have a .cross bar 25' to connect two switch units as shown in Figs. 1, 2 and i. The movable switch contact carryingarm [5 is hinged at 26 in the trip member :21 and biased to the open'and-to-the olosed'circuit positions by springs 21 connected to the lever 23 at 28 and to the switch arm i5 at 29.

In the closed circuit position of Fig. 3, the springs bias the actuating lever '01 its handle toward an abutment or stop Stand in the open circuitposition the lever presses against the sto pin {ii-on the trip member.

The latch strip .32 is hinged in the frame by the lugs 33 which rest in the bearings 34. An adjustable stud -35 carried-by the strip 32 is positioned by the notched end of the overload actuatorstrip l6 and is normally positioned in the path of movement of the trip :member 2| as shown .in .Figs. :3 and 5.

The spring 3-5 presses against the end of the latch strip to hold thelugs 33 in the bearing seats 34.

To :manually close the circuit, the actuating ,lever -23 is moved from .the position -:of Fig. 5

toward the position of Fig. 3. -As soon as :the

end 28 of lever :23 passes the -;plane which includes lugs 29 and pivots 24, thesprings .21 throw pull down on lugs '29 .and throw the switch arm I5 to the open .circuit position where the switch member-abuts against the .frame at 3?. When the finger .lever 2,5 is released, the springs .pull :the lever 23 against the .stop;pin :31.

.In case xii .an .overloadQin the circuit, .the Ibi- .metal strip 16 bends downwardly .nntil the .upper end of :stud 35 .frees the tip of .member f2| which tilts to the position of Fig. 6 under "the pull of springs 21. These springs connect lugs 29 on switch member 15 to lugs 28 on operating lever arm 23 and cause the thrust of member I to turn rocker 2|. This causes the right hand end of member I5 to rise above the line of pull about pivot 22 so that the springs 21 pull horizontally and downwardly on the lugs 29 and thus tilt arm l5 and open the circuit.

The switch may then be reset manually by moving the handle 25 from the position of Fig. 6 back to the position of Fig. 5 in which operation the lever 23 presses against the pin 3! and forces the trip member back into position for latching engagement with stud 35 as soon as the bimetal has cooled sufiiciently to permit spring 36 to return latch strip 32 to its normal inactive position.

In the automatic breaking of the circuit, the switch member [5 starts to slide across the face of the contact 52 just as the tension of the spring 2'! becomes effective so that there is no tendency to stick as is the case where the movement is merely at right angles to the contact surfaces. This sliding action is accomplished by reason of the fact that the trip member 2! which serves as an abutment for the switch member I5 is hinged at a point 22 beyond the pivot 24 of the lever 23 and the hinge 26 of the switch arm in the trip member lies between the

pivots

24 and 22. The switch arm therefore moves longitudinally as the trip member turns on its pivot 22, thus causing a more effective "action when breaking the circuit on an overload.

When two units are mounted together as shown in Figs. 1, 2 and 4, I provide an insulating block 49 connected to each latch strip 32 so that it moves with the latch. These blocks have spaced projections ii and 42 which coact to cause one unit to move the next adjacent unit after a short time. This sequential action is made possible by spacing the projections i! and 42 as shown in Fig. 4, the lost motion permitting the release of the unit which has been overloaded to take place independently.

Each unit has an element which is movable initially to release its circuit breaking mechanism and on continued movement causes tripping of the other units. The initial moving force is supplied by the current responsive device but the force required to trip the other unit is supplied by the conventional operating spring.

A great advantage of this system is that the loading on the latch of any unit i unaffected by the presence or absence of adjacent units and hence the calibration is unailected.

I claim:

1. In a circuit breaker, a stationary contact, a pivoted trip member, an overload latch normally interposed in the path of movement of the trip member, a switch member hinged to said trip member for coacting with said contact, a pivoted actuating lever and a toggle acting spring connecting said lever and said switch member, the hinge point of said switch member lying between the pivot of the actuating lever and the pivot of the trip member and at one side of a line connecting the pivots of the lever and the trip member so that the switch member slides longitudinally and swings away from the stationary contact when the trip member is released.

2. In a circuit breaker, a stationary contact, a pivoted trip member, a latch normally interposed in the path of movement ofthe trip member, a thermostatic actuator for said latch, a switch "member hinged to said trip member for coacting with said contact, a pivoted actuating lever and a toggle acting spring connecting said lever and said switch member, the hinge point of said switch member lying between the pivot of the actuating lever and the pivot of the trip member and at one side of a line connecting the pivots of the lever and the trip member.

3. In a circuit breaker, a stationary contact, a pivoted trip member, an overload actuated latch normally interposed in the path of movement of the trip member, a switch member hinged to said trip member for coacting with said contact, a pivoted actuating lever, a toggle acting spring connecting said lever and said switch member, the hinge point of said switch member lying between the pivot of the-actuating lever and the pivot of the trip member but at one side of a line connecting the pivots of the lever and the trip member and means of connection between said lever and said trip member for resetting the trip member and switch member.

4. A circuit breaker comprising a stationary contact, a movable switch member for coacting therewith, a pivoted trip member having a hinge bearing for the switch member located to move in direction away from said contact and cause the switch member to slide on said contact when the trip member turns, a pivoted actuating lever, a spring connecting said switch member and said lever at points which, when in closed circuit position, lie at one side of the pivot axis of said actuating lever and when in open circuit position lie on the opposite side of said pivot axis biasing said switch member to turn the trip member, and an overload latch coacting with said trip member to oppose its turning on its pivot.

5. A circuit breaker comprising a stationary contact, a movable switch member for coacting therewith, a pivoted trip member having a hinge bearing for the switch member located to move in a direction away from said contact and cause the switch member to slide on said contact when the trip member turns, a pivoted actuating lever, a spring connecting said switch member and said lever at points which, when in closed circuit position, lie at one side of the pivot axis of said actuating lever and when in open circuit position lie on the opposite side of said pivot axis biasing said switch member to turn the trip member, an overload latch coacting with said trip member to oppose its turning on its pivot and means of connection between the lever and trip member to permit resetting of said trip member.

6. A circuit breaker comprising a stationary contact, a movable switch member coacting with said contact, a pivoted trip member pivotally supporting said switch member in a plane offset from the plane including the pivots of said trip member and a manually actuated lever, a latch member spring-pressed against said trip member, a manually actuated lever pivoted between said trip member and said contact, a toggle acting spring connecting said lever and said switch member and a thermostatic overload member coacting with said latch member to release the trip member in case of an overload.

'7. In a circuit breaker, e, pivoted trip member, a switch member pivoted thereto, a'pivoted'actw 'ating lever, a main spring connecting said lever with said switch member at points which, when in closed circuit position, lie at one side of the pivot axis of said actuating lever and when in open circuit position lie on the opposite side of said pivot axis and biasing the trip member to turn in one direction, a pivoted latch member coacting with the trip member, a spring pressing said latch member against said trip member in opposition to the bias of the main spring and an overload member for retracting the latch memher from the trip member.

8. In a circuit breaker, a pivoted trip member, a switch member hinged to said trip member at one side of the pivot of the trip member, an overload latch interposed in the path of movement of the trip member at the opposite side of the pivot of the trip member, a pivoted actuating lever, and a toggle acting spring connecting the switch member and the actuating lever at points movable from one side of the pivot of the actuating lever to the other.

9. A circuit breaker comprising a stationary contact, a hinged switch member coacting therewith, a pivoted actuating lever, a main spring connecting said lever and said switch member at points which, when in closed circuit position, lie at one side of the pivot axis of said actuating lever and when in open circuit position lie on the opposite side of said pivot axis, an overload latch, a pivoted trip member having a hinge bearing for said switch member and normally held against said latch member by said spring, an auxiliary spring biasing said latch against said trip member, said trip member having a heel engaging said latch when released.

10. In a circuit breaker, :a hinged tripping member, a switch member pivoted to the tripping member, an actuating lever, a main spring connecting said lever and said switch member at points which, when in closed circuit position, lie at one side of the pivot axis of said actuating lever and when in open circuit position lie on the opposite side of said pivot axis, a spring pressed arm having a latch stud normally holding the tripping member from turning, an overload response device for retracting said arm and its stud and permitting said main spring to rotate said tripping member by the thrust of said switch member, said tripping member having a shoulder engaging said spring pressed arm to hold it depressed independently of the overload responsive device.

11. A multiple unit circuit breaker in which each unit is formed as set forth in claim 10 and each spring pressed arm has a lost motion interlocking element connected to an element of an adjacent unit.

12. A breaker unit as defined in claim 2 combined with another unit of similar construction and lost motion means of connection between the latch member of the two units.

13. The combination of two breaker units as set forth in claim 1 and lost motion means of connection between the latch members.

RAYMOND N. ROWE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,726,233 Krantz Aug. 27, 1929 2,329,362 Swingle Sept. 14, 1943 2,367,382 Taylor Jan. 16, 1945 2,447,652 Jennings Aug. 24, 1948