DE1116782B - Circuit breaker - Google Patents

Description

GERMAN

PATENT OFFICE

L 34865 Vrab / 21c

REGISTRATION DAY:

NOTICE THE REGISTRATION AND ISSUE OF EDITORIAL:

DECEMBER 7, 1959

NOVEMBER 9, 1961

There are circuit breakers known whose contact system when short-circuit currents occur as a result the electrodynamic forces acting on the contact system are opened very quickly. The shutdown the short-circuit current takes place within the first half-wave before the current has reached its full strength. The switch has a current-limiting effect. The dynamic effects the surge short-circuit current and the breaking work in the arc are thereby reduced.

In electrical networks with several series circuit breakers, for reasons the selectivity of the current-limiting switches only for those directly in front of the consumer Insert line outlet switch.

It is already a switch for power supply and distribution systems with selectively responsive Circuit breakers known, which cooperate with the moving contact with the same basic structure mechanical and electrical trip elements with different types of the fixed contact piece accessible lines is provided. The moving contact of this switch is designed as a lever and is under the action of a labile spring. The power supply to the fixed contact piece forms a Loop and consists of several detachably connected individual rails, their various types of connection with the external terminal and the fixed contact piece in the event of a short circuit once has an effect that increases the contact pressure and once has an effect that opens the contact system. Switches of this type can be used as current-limiting or as selectively staggered switches. However, their area of application is due to their special design of the contact system, especially the movable contact lever limited to lower nominal currents and lower short-circuit current values.

The invention relates to an electrical circuit breaker, ζ. B. for low voltage, with key switch and a contact system that can be opened by electrodynamic forces in the event of a short circuit can, with the same basic structure in terms of its trigger mechanism and the training of the Contact system both as a current-limiting switch and as a switch with adjustable tripping delay can be used for selective grading. The invention is that between the Switching mechanism and the (the) movable contact (s) or its support (their supports) interchangeable or intermediate elements which can be changed in their function are arranged, which can optionally be one of the key switch function independent electrodynamic and circuit breakers

Applicant:

LICENTIA Patent Administration -G. m. b. H., Frankfurt / M., Theodor-Stern-Kai 1

Heinz Fehling and Dipl.-Ing. Friedrich Bösoldt,

Neumünster, have been named as the inventor

or or electromagnetic or a contact opening caused only by unlatching the switch lock allow.

In order to give the switch one or the other function, it neither needs to be expanded nor disconnected from the network to be separated. The universal applicability is achieved with very simple mechanical means and therefore allows economical constructions. Special, extremely sweat-resistant contact material, z. B. silver graphite, but which tends to form conductive deposits on the switch walls not mandatory. In the switch according to the invention, the contact pressure of the contact system amplified by the short-circuit current until it is unlocked.

A few exemplary embodiments are to be explained with reference to the drawing for illustration. It shows

1 shows a diagram I = f (t) with short-circuit current profiles in the case of current-limiting rapid disconnection and delayed disconnection; Fig. 2a schematically shows an embodiment of the switch according to the invention, on which the mode of operation is explained in more detail. The various phases of movement of the contact system are shown. The switch has a current-limiting effect.

FIG. 2 b the same, but as a switch with an adjustable release delay; FIG.

3 shows a technical embodiment of the switch according to the invention;

Fig. 4 a, 4 b, 4 c a further technical embodiment of the invention as a current limiting Switch in different movement phases of the switch-off process.

109 738/309

Corresponding parts are provided with the same reference symbols in all figures.

In Fig. 1, the time course of short-circuit currents I = f (t) is shown in a diagram until they are switched off. With ^ ₁ the time from the beginning of the short circuit to its disconnection when using a current-limiting circuit breaker is denoted, with to the corresponding time with a normal circuit breaker. It can be seen that the stress on an electrical system due to the dynamic and thermal effects of the surge short-circuit current is considerably lower when using a current-limiting circuit breaker.

The invention is explained in more detail with reference to the schematically illustrated embodiment of a switch according to the invention in FIGS. 2a and 2b. 1 and 2 mean the current input and current output rails of the contact system. The fixed contact consists of the main contact piece 3 α, the intermediate contact piece 3 b and the tear-off contact piece 4. The movable contact, which is mounted on the contact carrier 7, is denoted by 5. The flexible connecting strip 6 forms the connection between the connecting rail 2 and the movable contact.

The contact carrier 7 is connected via the joint 8 to an insulating piece 11 which is rotatably mounted about the fixed point 9 and is provided with a guide and limiting hole 10. The contact carrier 7 is also supported by the pawl 12 against the rocker 13 which is provided with a roller 14 and which is connected to the contact crossmember 16 via the joint 15. The contact traverse 16 is also pivotably mounted about the fixed point 9 and is used to switch the contact system on and off. 17 is a tension spring which, when the switch is closed, supplies the contact pressure and, after the pawl 12 is unlatched, pulls the movable contact back together with the spring 18. The busbar 2 is guided through a magnetic release 20, which attracts its armature 21 when a short-circuit current occurs. The lever arm 22 acts on the insulating piece 11 in the direction of the arrow (A) . A second armature 23 triggers the switching mechanism via a linkage.

The mode of operation is as follows: As soon as a short-circuit current occurs, the armature 21 of the magnetic release 20 presses in the direction of arrow 04) on the insulating piece 11. This, or in the case of higher short-circuit currents together with the electrodynamic forces acting on the flexible connecting strip, lifts the movable contact 5 from the main contact piece 3α , wherein the contact rotates around the intermediate contact 3 b or rolls on it and then lies against the tear-off contact 4 with increased contact pressure. The contact carrier 7 is supported by the pawl 12/14 and the tension spring 17 against the rocker 13 held by the switching mechanism (not shown) in the contact opening direction at point 15 until the pawl 12 slides off the roller 14. A rotation of the insulating piece 11 around the fixed pivot point 9 by a few degrees is sufficient for this. After the contact carrier 7 has been unlatched, the tension spring 18, together with the tension spring 17, pulls the movable contact 5 into the open position I. The roller 14 rests in the boundary 19 of the carrier 7. At the same time, the armature 23 triggers the switching mechanism.

Then the contact traverse 16 is moved out of its switched-on position in the direction of arrow B and thereby takes the movable contact 5 and the contact carrier? up to the opening position II with. The lower limit of the elongated hole 10 in the insulating piece 11 is now on the fixed limiting bolt 24. The contact cross member 16 moves on in the direction of arrow B, the roller 14 rolling along the slope of the pawl 12 until it snaps back into place behind the pawl.

ίο The switch-off process is finished in this position and the contact system is ready to switch on again at the same time, position III.

Should the switch be selectively staggered within a row with adjustable tripping delay Switches are used, the contact carrier 7 is in the exemplary embodiment according to FIG. 2a 2b to be permanently coupled to the rocker 13 in accordance with FIG. This is done by changing the Pawl 12 and roller 14 against triangle 25,

ao which is permanently connected to the contact carrier 7 via the joint 27. All other switch parts remain unchanged. The arrangement works as follows:
- When a short-circuit current occurs, the movable contact performs a rolling movement around the intermediate contact piece 3 b under the action of the electromagnetic forces of the trigger 20 and the electrodynamic forces of the current loop 6 and rests against the tear-off contact 4 with increased contact pressure Main contact piece 3 a . The joint 27 bends upwards, the triangle 25 rotating about the pivot point 26. The contact system remains in this position until the triggering of the switching mechanism initiates the movement of the contact cross member 16. Triangle 25, contact traverse 16 and rocker 13 occupy the position IIb and finally the final open position IUb.

In Fig. 3, a technical embodiment according to FIG. 2 a is given. Corresponding to each other Parts have the same reference numbers.

4 a, 4 b, 4 c show a further embodiment according to the invention. The desk is shown in its current-limiting embodiment. 1 and 2 are again the power supply or discharge rails designated. 3 is the main, 4 the breakaway contact of the fixed Contact. The movable contact 5 is on the flexible connecting strip 6 with the busbar 2 in Link. It is also connected to the shift lever 30 via the rigid coupling 29 and the knee joint 28. 34 and 35 are return springs, 31 is the contact compression spring. Switch lock and switch mechanism act via linkage 32 and angle lever 33. The switch works as follows:

When a short circuit occurs, the movable contact 5 is electrodynamic Forces in the current band 6 rotated about its point of support on the tear-off contact piece 4. The main contact pieces separate, the contact pressure at the tear-off contact increases until the driving pin 36 pushes the knee joint 28 upwards. The moving contact is now unlocked and will in a very short time thanks to the electrodynamic opening forces and the return springs 34 and 35 in brought the open position of FIG. 4 b. Meanwhile the lock has opened and the moving contact falls into the final open position according to FIG. 4 c. There-

when the stop 37 pushes the knee joint down so far that the switch is in this position is ready to be switched on again.

If you make the knee joint ineffective, z. B. by replacing it with a rigid coupling, it becomes from the current-limiting opening switch is a normal circuit breaker, the one with a conventional delay device provided can be used in systems with selectively staggered switches.

IO

Claims (4)

PATENT CLAIMS: 1. Electrical circuit breaker, e.g. B. for low voltage, with a switch lock and a contact system that can be opened in the event of a short circuit by electrodynamic forces, which can be used with the same basic structure in terms of its trigger mechanism and the design of the contact system both as a current-limiting switch and as a switch with adjustable release delay for selective grading is, characterized in that between the switch lock and the (the) movable contacts) or its carrier (their carriers) interchangeable or changeable in their function intermediate members are arranged, which optionally have an electrodynamic and / or electromagnetic or only one independent of the switch lock function Allow contact opening caused by unlatching the key switch. 2. Electrical circuit breaker according spoke 1, characterized in that the intermediate members either a detachable or detachable or an unsolvable or non-detachable Effect coupling between the key switch and the movable contact. 3. Electrical circuit breaker according to claim 2, characterized in that as intermediate members two-part or multi-part coupling members, e.g. B. pawls, knee joints or replaceable one-piece, z. B. rigid coupling links are used. 4. Electrical circuit breaker according to spoke 1 and 2, characterized in that mechanical locking members are provided, which the number of possible degrees of freedom of Allow coupling links to be changed. Considered publications:
British Patent No. 165 563. For this purpose 2 sheets of drawings © 109 738/309 10.61