US1808441A - Electromagnetic automatic circuit breaker - Google Patents

Description

June 2, 1931. H. TRINKL 1,808,441

ELECTROMAGNETIC AUTOMATIC CIRCUIT BREAKER Filed Aug. 19, 1929 2 Slreecs-Sheel l Patented June 2, 1931 PATENT OFFICE HANS TRINKL, F AUGSBURG, GERMANY ELEUEROMAGNETIC AUTOMATIC CIRCUIT BREAKER.

Application led August 19, 1929, Serial No. 387,072, and in Germany September 7, 1928.

the dimensions of the circuit breaker wouldA grow up to a practically inadmissible eX- tent. This limitation is dispensed with by the present invention by the fact that the magnet coil of the circuit breaker in its closed position is formed by the conducting l parts of the contacts themselves and the parts interconnecting them. The coil so formed naturally has so large conductive cross sections that it can be used without any change for current strengths within wide limits, for instance up to amp. In a coil of this design the breaking motion for instance may take place normally to the axis of the coil and to the radius of the coil directed toward the contact points, so that the arcs are blown away along this radius. To boost the strength of the magnetic field of the coil I provide a closed iron frame which further serves to carry the breaking mech- 3o traordinarily simple construction of the circuit breaker even in the special case where the electro-magnetic trip device is combined with a thermally acting and a hand trip.

In order that my invention can be more readily understood, a preferred embodiment of the same is illustrated by way of example in the drawings which accompany and form part of this specification. In these drawings Figure l is a lateral view of my improved automatic circuit breaker, the procelain case thereof being shown in vertical section,

Figure 2 is a view seen from below, of the main insulating body of the circuit breaker, Figure 3 is a vertical section through the circuit breaker,

Figure 4 is a similar section normal to that of Figure 3, and

Figure 5 is a detail of the breaking mechanism.

anism. These arrangements result in an eX- K The circuit breaker illustrated comprises siX points of break that are connected in serles.

Referring to these drawings, l to 6 denote the fixed contact pieces formed by bolts while the movable contact pieces are designed as bridges denoted by la to 6a, see Figures l, 2 and 3. The contact bolts 1 to 6 are mounted in an insulating body 9 and are connected on the lower side thereof by bars 7 and 8, as to be seen from Figure 2. In the closed position of the circuit breaker the contacts therefore form closed windings or so to speak a coil. To boost the strength of the magnetic field ofthis coil an iron frame 10 is arranged which consists in two parallel sheet metal plates or piles interconnected within the coil by a transverse central portion. These plates serve as bearings for the pivot pins of the mechanical breaking mechanism which is described hereinafter, and of the trip armature 14. This armature is formed by a two-armed lever fulcrumed on a pin l5, Figure 3. The iron frame 10 is mounted on the insulating body 9 by screws 12, 13. Screw 12 further serves to supply the current and to this end is insulated relatively to frame l() and connected to the contact bolt l by a bar 24, Figure 2.

The xed contact pieces l to 6 are arrangedpairwise on both sides of the central portion of frame 10. On its longitudinal sides the latter is embraced by the insulating body 9 so that chambers ll for the contact pieces are formed, Figure 1. These chambers are open in the breaking direction but insulated from one another and closed transversely thereto, that means in the blowing direction of the arcs, by the porcelain case 25.

The movable contact pieces la to 6a are mounted side by side on an insulating body 29 and project through apertures 30 of frame 10, Figure 4. The insulating body 29 is connected to the breaking mechanism by means of a sleeve 32.

The breaking mechanism is designed as follows:

Sleeve 32 has shiftably mounted in it a bolt 34 which touches the attractable arm extending up to the central axis of the circuit breaker, of the trip armature 14 when this arm is not in attracted position. A flat spring 33 is attached to the sleeve 32 which spring has rolled-in ends and is guided by two cross pins 35 in slots 36 provided in frame 10, Figure 3., The rolled-in ends of spring 33 rest in open bearings 38 of slides 39 hinged on their ends each to a toggle lever 40. The pins 41 of this hinged conneetion are guided in slots 42 of frame 10. On their other ends the toggle levers 4() are hingedly connected to a bolt 43 which can be shifted in slots 45 of frame 10 by depression of a push button or knob 44. The slots 45 so farextend downward that the toggle levers are enabled to be moved a slight amount beyond their straight position so as to lock themselves in extreme position. The push Abuttonvor knob -44 is guided in a suitable bore of the cover 48 of the porcelain case 25.

The porcelain case 25 possesses the usual base cap with a cap screw 26 which is conductively connected to the contact bolt 6 by a bar 27, and, further, to the normal central contact`- 28 conductively connected to screw 12.

This connection between contact 28 and screw 12 is established in the embodiment illustrated by a thermally acting trip mem'- ber. To this end the insulating body 9 has a central hollow cylindrical extension 16, Figures 3 and 4, wherein this trip member 17 is lodged. The latter has the shape of a wlre or strip and is rigidly connected on its lower end to a threaded bolt 18. The latter engages a threaded sleeve 19 fixed on extension 16 by a nut`20. This arrangement enables the wire 17 to Vbe adjusted'in axial direction. The upper end of the thermally acting trip member 17 is connected to a flat spring 21, see best Figure 3, which is insulated relatively to the iron frame 10 by an insulating plate 22 and is fixed thereon by the screw 12 and a nut 23.. -The free end of spring 21 abuts on an insulating plate 14a mounted on the free end of the' attract'- able arm of armature 14. The thermally acting trip member 17 thusacts directly upon armature 14.

The extension 16 may be filled with any material that admits to carry off the heat in a suitable manner.

' The embodiment illustrated further comprises an arrangement for tripping the cir '39 inward. Consequently spring 33 is ten- The current then flows from the central Contact 28l through sleeve 19, setting bolt 18, the thermally acting trip mem'ber 17, spring 21, screw 12, bar 24, contacts 1 to 6, bar 27 to the cap screw 26 of the porcelain case. 25.

When short-circuit occurs, the electromagnetic field generated in the iron frame 10 becomes so strong that armature 14 is attracted. Consequently bolt 34 is lifted and urges the toggle levers 40 upward out of their straight position; Thereby spring 33 is unlocked and violently lifts the contact pieces 1a to 6a from the fixed contact pieces 1 to 6 so that the current is broken. This breaking motion takes place normally to the axis of the coil and to its radius directed to the Contact points so that the arcs wire 17 then expands and by means of spring 21 exerts a pressure 011 the insulating plate 14a so that armature 14 lifts bolt 34 and causes break of the contacts 1 to 6 in the manner described above. The interruption of the circuit by means of the thermally acting trip member 17 can be adjusted in dependence on the current strength by setting bolt 18. In the same sense the filling mass of extension 16 which carries off the heat becomes operative.

The direct action of trip member 17 upon armature 14 has the very important effect of the electro-magnetic trip taking place very quickly when' short circuit occurs, so that member 17 cannot be injured.

To enable the toggle levers 40 to be urged to breaking position independently of the position of 'button 44, the connection of the `toggle levers Wit-h the pin 43 of button 44 may be designed so as to not be a rigid but a detachable one. To this end the bearing eyes 'of the levers are open so as to form downward directed hooks so that even when button 44.- is firmly held in down position the toggle levers are lifted by bolt 34 when an overload or short circuit occurs. For, as soon as the levers 4() have then passed through straight position and spring 33 bel Letters Patent is l. An automatic circuit breaker of the type described comprising' an electro-magnetic trip device and a breaking mechanism adapted to be actuated thereby, said trip device comprising a coil and an armature, said coil being formed by a plurality of contacts of said trip device which are interconnected When the circuit breaker is in closing position.

2. An automatic circuit breaker of the type described comprising an electro-magnetic trip device and a mechanical breaking mechanism adapted to be actuated thereby, said trip device comprising a coil and an armature, said coil being formed bya plurality of contacts of said device which are interconnected when the circuit breaker is in closing position, said coil being adapted to be broken by its action upon said mechanism.

3. An automatic circuit breaker of the type described comprising an electro-magnetic trip device and a breaking mechanism adapted to be actuated thereby, said trip device comprising a coil and an armature, said coil being formed by a plurality of contacts of said device which are interconnected, when the circuit breaker is in closing position, the breaking motion of said mechanism being directed normally to the axis and that radius of said coil which is directed toward saidA contacts.

4. An automatic circuit breaker of the type described comprising an electro-magnetic trip device and a mechanical breaking mechanism adapte-d to be actuated thereby',

-said trip device comprising a` coil and an armature, said coil being formed by a plurality of contacts of said device which are interconnected When the circuit breaker is in closing position, and said coil being adapted to be broken by its action upon said mechanism, and a closed iron frame adapted to carry said mechanism and to form the core of said armature.

5. An automatic circuit breaker of the type described comprising an electro-magnetic trip device and a mechanical breaking mechanism adapted to be actuated thereby, said trip device comprising a coil and an armature, said coil being formed by a plurality of contacts of said device which are interconnected when the circuit breaker is in closing position, and said coil being adapted to be broken by its action upon .said mechanism, and a closed iron frame adapted to form the core of said armature and consisting of two lateral Walls and a transverse connecting piece located Within said coil, said lateral Walls consisting each of at least one sheet met-al plate, the movable parts of said mechanism and said armature being hingedly mounted on said Walls.

6. An automatic circuit breaker of the type described comprising an electro-magnetic trip device and a mechanical breaking mechanism adapted to be actuated thereby, said trip device comprising a coil and an armature, said coil being formed by a plurality of contacts of said device which are interconnected when the circuit breaker is in closing position, and said coil being adapted to be broken by its action upon said mechanism, and a closed .iron frame adapted to carry said mechanism and to form the core of said armature and consisting of two lateral Walls and a transverse connecting piece located Within said coil, the fixed contact pieces of said contacts being arranged pair- Wise on both sides ot said transverse piece and the movable contact pieces being bridgeshaped and projecting through openings of said lateral walls.

7. An automatic circuitbreaker according to claim 6, comprising an insulating body ixed to said frame and having chambers open in the breaking direction but closed and insulated from one another in the blowing direction of the arcs, one pair of said contacts being lodged in each of said chambers, and the ixed contact pieces of said contacts being mounted on said insulating body.

8.' An autolnatic circuit breaker according to claim 6, comprising a trip bolt adapt-ed to be actuated by said armature and to act upon said breaking mechanism and arranged in the central axis of the circuit breaker, said armature being formed by a two-armed lever one arm ot which is adapted to co-operate with said bolt.

t). An automatic circuit breaker according to claim 6, comprising a carrier for the movable parts of said contacts, a fiat spring having said carrier suspended therefrom, a toggle lever mechanism adapted to tension said spring, and a push button adapted to actuate said toggle lever mechanism, said toggle levers being adapted to assume a closing locked position beyond their straight position.

l0. An automatic circuit breaker according to claim 6, comprising a carrier for the movable parts of said contacts, a flat spring having said carrier suspended therefrom, a toggle lever mechanism adapted to tension said sprlng, and a. push button adapted to actuate said toggle lever mechant-m, said toggle levers beingadapted to assume a closing locked position beyond their straight position, and said toggle levers being hinged on said push button by means of eyes open in the' direction of the .closing motion.

11. An automatic circuit breaker according .to claim 2,comprising a hand-operated auxiliary trip device comprising a manipulative means adapted to immediately act lo upon said armature. Y

l2. An automatic circuit breaker according to claim 6, comprising an insulating body fixed to said frame and having chambers open in the .breaking direction but closed and insulated from one another in the blowing direction of the arcs, one pair of said contacts being lodged in each of said chambers, andthe iixed contact pieces of said contacts being mounted on said insulating body, and a thermally acting trip device having a thermally actuated member lodged in a chamber of said insulating body and adapted to directly act upon said armature.

13. An automatic circuit breaker according to claim 6, comprising an insulating body fixed to said frame and having chambers open in the breaking direction but closed and insulated from one another in the blowing direction of the arcs, one pair of 0 said contacts being lodged in each of said chambers, and the fixed contact pieces of said contacts being mounted on saidinsulating body, and a thermally acting trip device having a thermally actuated member' lodged in a chamber of said insulating body and adapted to directly act upon said armature, said chamber being filled with a material adapted to permit the heat to be carried away in a regulated manner.

4o 14. An automatic circuit breaker according to claim 6,' comprising an insulating body fixed to said frame and having chambers open in `the breaking direction but closed and insulated from one another in the blowing direction of the arcs, one pair of said contacts being lodged in each of said chambers, and the fixed contact pieces of said contacts being mounted on said insulating body, a thermally acting trip device 504 having a thermally actuated member lodged in a chamber of said insulating body and adapted to directly act upon said armature,

, said chamber being filled with a material adapted to permit the heat to be carried away in a regulated manner, and means for setting said thermally actuated member comprising a set screw adapted to adjust said member and a spring adapted to urge said member against said armature.

In testimony whereof I atiix my signature.

' HANS TRINKL.

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