US2298053A

US2298053A - Automatic circuit breaker

Info

Publication number: US2298053A
Application number: US315608A
Authority: US
Inventors: Helland John Hilmar
Original assignee: WILLIAM M PEARSON
Current assignee: WILLIAM M PEARSON
Priority date: 1940-01-25
Filing date: 1940-01-25
Publication date: 1942-10-06
Anticipated expiration: 1959-10-06

Description

Oct. 6, 1942. J. H. HELLAND 2,298,053

AUTOMATIC CIRCUIT BREAKER Filed Jan. 25, 1940 2 Sheets-Sheet l 2', ATTORNEY-SE;

Oct. 6, 1942. .1. H. HELLAND 2,298,053

AUTOMATIC CIRCUIT BREAKER Filed Jan. 25, 1940 2 Sheets-Sheet 2 r 4/ 3/ so I 3g i353 3/ y 42 44 29! 4.5 1 i?" 2 Z8 ,9 2 T z 46 g x 6 37 g 2 55 1 40 4/ I I I l 3/ 33 I I l I l i H 30 42 44 1 I w 45 24 2e A /9 I U l I 57 y g I a7 49 T JHfleZZaraZ -/z I INVENTOR. J"

47 ATTORNEYS.

Patented Oct. 6, 1942 AUTOMATIC CIRCUIT BREAKER John Hilmar Helland, Newark, Ohio, assignor of one-third to William M. Pearson, Newark,

Ohio

Application January 25, 1940, Serial No. 315,608

Claims.

This invention relates to an automatically controlled circuit breaker, designed for use in the usual fuse plug socket of an electric line, the primary object of the invention being to provide means for breaking the circuit in which the device is located, when a short or overload occurs in the circuit, thereby protecting the circuit and appliances connected therein.

An important object of the invention is to provide a device of this character which maybe readily reset after it has operated to break the circuit, and after the defective line or appliance has been repaired, thereby eliminating the necessity of installing a new circuit breaker in thecircuit.

Another important object of the invention is' to provide a device of this character including a stationary contact and a movable contact,,the

movable contact being positioned and constructed in such a way that it will snap into engagement c with the stationary contact, completing the circuit, thereby eliminating any possibilit of arcing, when the movable contact member engages the stationary contact member.

With the foregoing and other objects in view,

which will appear as the description proceeds, the invention resides in the combination and arrangement of 'parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein described,

may be made within the scope of what is claimed,

without departing from the spirit of the invention.

Referring to the drawings:

Figure 1 is a longitudinal sectional view through a device constructed in accordance with the invention.

Figure 2 is a sectional view taken on line 2-2 of Figure 1.

Figure 3 is a sectional view taken on line 3-3 of Figure 1.

Figure 4 is a sectional view taken on line 4-4 tion of the circuit breaker which is formed'with a reduced end portion 6 formed with threads to accommodate the screw sleeve 1 that has an inwardly extended annular flange 8 formed at the lower end thereof. This annular flange provides a support for the insulating member 9, through which the contact wire 10 extends, the wire l0 being connected with the solenoid coil 1 I mounted within the reduced end portion of the shell or body portion 5.

The coil II is mounted on the spool-like sup port 12, and is secured in position by means of the screw l3' which is shown as extended through the plate l4 that closes the lower end of the reduced portion 6.

Mounted within the support I2, is a coiled spring indicated at l5 which is of the contractile type, the lower end of the spring being secured to the support l2, at I6. The upper end of the spring [5 is secured to the movable contact support i! so that the normal tendency of the spring i5 will be to draw the movable contact support l7 downwardly, or towards the coil I I.

Contact ring indicated at I8 is secured to the movable contact support 17, as clearly shown by Figure 1 of the drawings.

As clearly shown by Figure 1 of the drawings, the bod portion is provided with a plurality of bores disposed longitudinally thereof, the bores being of diameters to accommodate the coiled springs 19, which springs are of the expansible type. These springs are arranged in predetermined spaced relation with respect to each other, in a circular line.

The movable contact support I! is formed with a depending annular flange 2i! inside of which the armature 2| moves. The armature 2| is mounted on the lower end of the rod 22, which is formed with a lower tapered section 49. The upper end of the rod 22 is threaded, and extends into the threaded opening of the disk 41. Mounted within the shell or body portion 5, is a disk- 24 that supports the split tube 25, the tube 25 being provided with slots extending inwardly from the lower end thereof, providing a plurality of fingers 26. heads 21 that contact with the inner surface of the depending annular flange 29, under normal conditions. The disk 24 is of a diameter to rest on the coiled springs i9 to the end that under normal conditions, the action of the springs 19 will be to urge the disk 24 upwardly. A disk of mica or similar insulating material is indicated at 28, and insulates the disk 24 from the springs IS.

The split tube 25 is of a diameter appreciably These fingers are provided with larger than the diameter of the rod 22, providing a housing for the coiled spring 29 which normally acts to urge the disk 41 upwardly.

Pins indicated by the reference character 30 extend upwardly from the disk 24 and are adapted to be engaged by the cams 3| depending from the cap 32. These cams 3| are provided with straight end portions 33, so that when the cap is rotated to cause the cams to move the pins, the pins will snap from the cams at the straight ends thereof, for purposes to be hereinafter more fully described.

The disk 24 is also provided with an upstanding flange 34 to which the disk 35 is connected, the disk 35 providing the cover for the thermal element. The disk 23 is disposed between the cover disk 35 and thermal element 36, the disk 23 being shown as resting on the thermal element at all times. The thermal element embodies disks connected at their edges and formed with annular corrugations, and constructed of bimetallic or special alloy, thermo-magnetic material, which will bulge when the disk expands under heat, due to an abnormal condition in the circuit, with the result that the armature is drawn through the fingers, releasing the fingers 26 to the action of the coiled spring I9, which forces the movable contact support I! and contact mounted thereon, away from the stationary contact 31, breaking the circuit.

The contact member with which the contact l8 cooperates in completing a circuit, is indicated by the reference character 31, and is in the form of segmental contacts against which the contact l8 engages. the circuit between the solenoid coil II and stationary contact 37, the return circuit being made through the wire 39 that connects with the contact 37 at the opposite side thereof, the wire 39 being in circuit with the screw sleeve 1.

A stem indicated at all extends from the button 4| through the cover disk 35 and connects with the disk 23 that rests on the thermal unit 36.

Carried by the cap 32, is a ring 42 which is formed with a groove in its periphery, the groove accommodating the spring member 43 which is in the form of a split ring constructed to expand beyond the periphery of the ring 42 so that portions thereof will extend into the groove 44 formed in the shell or body portion 5, near the upper end thereof. This spring member allows the cap to rotate, but at the same time prevents the cap from moving longitudinally of the body portion.

Ring member 42 is prevented from rotating within the housing, by the lugs 45 that extend from the periphery thereof, and are seated in recesses formed in the inner surface of the shell or body portion 5,

It might be further stated that the stationary contacts 31 are prevented from rotary movement, by the lugs 46 that extend from the periphery thereof, and lie in recesses formed in the inner surface of the body portion 5.

The operation of the automatically controlled switch or circuit breaker is as follows: When the device is positioned in a. fuse plug socket, the movable contact member is in the position shown by Figure 1 of the drawings. The cap 32 is now rotated in a clockwise direction resulting in the cams 3| directing a downward movement of the pins 3!], disk 24 and split tube 25. Since the disk 47 supports the rod 22 and the coiled spring 29 is positioned between the disk 41 and heads 21 A wire indicated at 38 establishes of the fingers 26, it will be seen that downward pressure moves the rod 22 downwardly until the sleeve and rod 22 are in positions as shown by Figure 6 of the drawings. The heads 21 are now in expanded position below flange 20 due to the fact that downward movement of the disk 24 moves the free ends of the fingers over the tapered portion 49 of the armature 2|. Upon further rotary movement of the cap 32, the cams move so that the pins 30 snap over the straight end por tions 33 thereof. With this movement, the mov-' able contact support i together with the contact ring l8, are moved upwardly since the contact support l1 has become connected with the split tube 25, whereupon, the contact ring l8 engaging the stationary contact segment 31, complete a circuit through the device.

Assuming that a short occurs in the circuit, the coil II will become energized resulting in the armature 2| being drawn downwardly. It will of course be understood that when the device is in its set position, the spring IE will be placed under tension. As the armature 2| moves away from the fingers 26, the fingers contract due to the resiliency thereof, leaving the movable contact support whereupon the coiled spring l5 snaps the movable contact ring l8 downwardly away from the contact member 31, breaking the circuit.

When the device is in a set position, and an overload occurs in th circuit, the coil II will become heated, causing the thermal element to expand. As the thermal element expands, the disk 41 is forced downwardly moving the rod 22 to a position where the tapered portion thereof disengages the fingers. With this movement, the coiled spring l5 contracts to move the movable contact ring I8 out of engagement with the stationary contact segment 31, again breaking the circuit.

It might be further stated that when it is desired to break the circuit, the button 4| is manually depressed, and when the device is to be reset, the cap 32 is rotated in a clockwise direction, as described.

From the foregoing it'will be seen that due to the construction shown and described, the device may be readily and easily set for operation, after the line or circuit has been repaired, without the necessity of providing a new circuit breaker.

What is claimed is:

1. An automatically controlled circuit breaker comprising a body portion adapted to be screwed into a fuse plug socket of an electric circuit, a stationary contact member within the body portion, a movable contact member within the body portion and adapted to complete a, circuit with the stationary contact member, a solenoid in the circuit with the contact members and mounted within the body portion, said solenoid including an armature embodying a stem formed with a cam surface, a movable member within the body portion, spring fingers carried by the movable member and normally engaging the cam surface, said fingers adapted to expand by movement of the fingers over the cam surface of the armature stem of the solenoid, connecting the movable member and movable contact member, means for moving the movable member whereby the movable contact member is moved into engagement with the stationary contact member, completing a circuit, and said solenoid adapted to disengage the fingers releasing the fingers when an abnormal condition occurs in the circuit, and means for operating the movable contact member to disengage the stationary contact member, breaking the circuit.

2. An automatically controlled circuit breaker comprising a body portion adapted to be secured in a fuse plug socket of an electric circuit, a stationary contact member within the body portion, a movable contact member within the body portion, a support for the movable contact member, said support including an annular flange, a movable member mounted within the body portion and including spring fingers, adapted to extend to a position adjacent to the annular flange of the movable contact member, a solenoid within the circuit and including an armature stem having a cam surface formed thereon movabl between the spring fingers and adapted to expand the spring fingers into frictional contact with the flange of the movable contact member support, means for moving the movable member and movable contact member whereby the movable contact member engages the stationary contact member completing the circuit, said solenoid adapted to be energized when an abnormal condition arises in the circuit, whereby the cam surface moves away from the spring fingers, releasing the movable contact member, and spring means for actuating the movable contact member to break the circuit.

3. An automatically controlled circuit breaker comprising a body portion adapted to be screwed into a fuse plug of an electric circuit, a stationary contact member and a movable contact member mounted within the body portion, a movable member above the stationary contact member, spring fingers carried by the movable member, a solenoid having a tapered armature stem mounted within the body portion the tapered portion of said armature stem adapted to extend between the spring fingers expanding the fingers into engagement with the movable contact memher and connecting the movable member and movable contact member, said armature stem adapted to move between said spring fingers in one direction, releasing the fingers, when the solenoid is energized due to an abnormal condition in the circuit, and means for moving the movable contact member out of engagement with the stationary contact member breaking the circuit when the movable contact member is released by said fingers.

4. In a device of the character described, a body portion adapted to be screwed into a fuse plug of an electric circuit, a stationary contact member and a movable contact member mounted within the body portion, a latch adapted to normally hold the contacts together, said latch comprising a tube split longitudinally from one end, providing spring fingers, a solenoid in the body portion and embodying a tapered armature stem adapted to move between the spring fingers urging said spring fingers laterally into frictional engagement with the movable contact member connecting said movable member and said movable contact member, yieldable means adapted to move said movable contact member to a position closing a circuit between the movable contact member and stationary contact member, and said tapered armature stem adapted to move releasing said fingers and freeing said movable contact member when the solenoid becomes energized, and a spring adapted to move the movable contact member away from the stationary contact member breaking the circuit.

5. An automatically controlled circuit breaker comprising a body portion adapted to be screwed into a fuse plug socket, a stationary contact member including an annular flange, mounted within the body portion, a movable contact member mounted within the body portion and adapted to engage the stationary contact member completing an electrical circuit, a movable member extending through the movable contact member, said movable member embodying a tube split longitudinally providing a plurality of spring fingers, a solenoid within the body portion and in circuit with the contact members, a tapered stem forming a part of the solenoid and adapted to extend into the split sleeve expanding said fingers into frictional engagement with the annular flange holding the sleeve and movable contact together in a set position, said solenoid adapted to Withdraw the said tapered stem, releasing the fingers, and a spring adapted to move the movable contact member away from said stationary contact member breaking the circuit.

JOHN HILMAR HELLAND.