DD204343A1 - PIPING PROTECTION SWITCH IN NARROW CONSTRUCTION - Google Patents

Abstract

The invention relates to a miniature circuit breaker with a centrally mounted two-armed switch contact frontally in front of the Loeschkammer. It is an object of the invention to ensure a high opening speed and a low parts and production costs. This is achieved according to the invention, in that the switching contact has a lever arm on the back, on which a connecting bracket acts on the switching mechanism, that the contact force is generated by a torsion spring arranged in the switching contact bearing and that the return spring is designed as a powerful tension spring, which directly over the connecting bracket on the lever arm of Switching contact attacks and in their direction of effect with the geometric direction of the connecting bracket agrees.

Description

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Miniature circuit breakers in narrow construction To the application field of the invention

The invention relates to a switching mechanism for a Leitungsjsschutzs ehalt he narrow in construction and low height with a thermal and magnetic ¬ trigger and a center frontally mounted in front of the quenching chamber two-armed Schalt «contact.

Ch arakteristik the known technical solutions

In this context, it has already been proposed to mount the switch contact in the center, frontally in front of the quenching chamber in the region of its center of gravity rotatable, resulting in a low Massenträghe-its moment for the movement of the switching contact e-s results (WP HO1H / 225237).

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This arrangement ensures a high contact opening speed and a high running speed of the Schaltlichbogens on the switch contact, so that the small gap to tangential lower guide rail has no adverse effect on the rapid entry of the arc into the quenching chamber.

Known technical solutions, which have a front side of the quenching chamber arranged switching contact, usually have the disadvantage that several parts of the switching mechanism when triggering the switch must be moved in case of short circuit and thus reduce the opening speed of the switching contact.

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For example, it is proposed in DE-GM 7500O6O to store the contact arm above the arc chamber and form so that in the on state its end extends directly to the lower arc guide plate. With this arrangement, a favorable shrinkage of the arc is also ensured in the quenching chamber. The disadvantage is that in this technical solution, the Verklinkungsteile the switching mechanism are mounted on the contact arm and must be moved during the opening process,

, Aim of the invention

The aim of the invention is to find a switching mechanism which avoids the mentioned deficiency of the already known technical solutions regarding the achievement of a high opening speed.

.Development of the essence of the invention

The object of the invention is to find a simple switching mechanism for a circuit breaker of the type mentioned, which in training the contact and extinguishing system with a centrally, frontally in front of the extinguishing chamber in the region of its center of gravity rotatably mounted .Schaltkontaktes the advantages achieved with respect to the achievement a high contact opening speed and a rapid retraction of the arc -in the quenching chamber maintains and beyond the necessary functions for a circuit breaker, such as z, B. Freiauslösung, manual override and ensures AusstromauslÖsung required only a small footprint, at the same time the parts and Production costs are kept low and the design of the individual parts is simple and easy to assemble ",

The object is achieved by the fact that the center, frontally mounted in front of the extinguishing chamber two-armed switching contact on the back of a-n lever arm, its effective length

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approximately half of the Äbstandes between Schaltkontaktdrehlager and contact point corresponds to the fact that a connecting bracket acts on this lever arm, which establishes the connection to the switching mechanism as a movable element, that the contact force is generated by a torsion spring which is arranged in Schaltkontaktdrehlager, and that the return spring Tension spring is formed, engages directly on the connecting bracket on the lever arm of the switching contact and their direction of action coincides with the geometric direction of the connecting bracket. This design of the switching mechanism is achieved that result in the event of a short circuit when opening the switch favorable conditions for a high opening speed.

The powerful return spring has its entire tensile force to move the switch contact available and needs only to accelerate the designed as a U-shaped wire bend connecting bracket with its low mass. The selected lever ratio supported by the thus required low Ausschaltweg also achieving a high contact opening speed «, The arrangement of the contact force-forming torsion spring in the pivot bearing of the switching contact also favors the maintenance of the low moment of inertia of the switching contact.

embodiment

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The invention will be explained in more detail with reference to an embodiment. The accompanying drawing shows the interior of a circuit breaker in Schmälbauweise and low height with a center, frontally mounted in front of the quenching chamber 1, two-armed switching contact 2 with a running according to the features of the invention simple switching mechanism in the off position.

The switch has a magnetic release 3, which is arranged on the i erating chamber 1, and a thermal release 4 »The upper guide rail 5 is connected to the fixed contact 6, and together with the magnetic release 3 and the terminal 7 is a structural unit. The lower guide rail 8 is extended beyond the Vorkammerraum 9 out and is gleich- _: timely the attachment for the thermal release 4 "on the extension of the F.ederwinkels 10, the electrical connection j is made to the terminal 11 and the lower guide rail. 8

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The two-armed switch contact 2 is mounted centrally in front of the quenching chamber 1 rotatable in the region of its center of mass on an axis 12 \ and thus has a low moment of inertia «, \ The lower guide rail 8 touches the lower end of Schaltkon- J takt it 2" With this arrangement ensures that the base of d.es resulting at the contact point 13 switching arc on the one hand on the fixed contact 6 and the associated, J upper guide rail 5 and on the other hand on the switching contact 2! and the tangent lower guide rail "8 can move through defects without additional delay and the switching light arc quickly enters the quenching chamber 1;

Via the rear lever arm 14 of the switching contact 2, whose effective length is approximately half the distance between the axis of rotation 12 _; and contact point 13, the mechanical drive takes place. , The connection to the switching mechanism, which is formed by the shift lever 15 which forms a knee joint with the connecting plate 16, a rotatably mounted latching element 17 with a slotted guide 18 and a half shaft 19 as a pawl element, is carried out by a connecting bracket 20, the u -shaped bent wire part is designed. At the lower leg of the connecting bracket 20,

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engages in the lever arm 14 of the switching contact 2, which is

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formed as a strong tension spring return spring 21 mounted. The return spring 21 is on the other hand fixed so that its direction of action coincides with the geometric direction of the connecting bracket 20. At the same time, a s _c henkl of the contact force-generating torsion spring 22 is supported at this point. This torsion spring 22 is also mounted on the axis of rotation 12, whereby no additional moment of inertia arises during the turn-off, - '

The switch is turned by movement of the shift lever 15 counterclockwise by hand, About the connecting plate 16, the upper leg of the connecting bracket 20 is guided in the slotted guide 18 of the Verrastungselementes 12 upwards. This movement is transmitted via the connecting bracket 20 to the switching contact 2, whereby this applies to the fixed contact 6. At the same time the return spring 21 is tensioned and after the application of the switching contact it 2 to the plunger contact 6 also the contact force-forming torsion spring 22,

Upon the occurrence of a short circuit, the pin 24 of the magnetic release 3 strikes the lever projection 25 of the half shaft 19, whereby the latching element 17 is released with the pivotal movement of the half shaft 19. At high short-circuit currents-n of the lever attachment 25 acts as a punch on the over, the contact point 13 also extended switching contact 2, The opening movement of the switching contact 2 is accelerated by the return spring 21. Due to the low moment of inertia of the switching contact it 2 • while a high opening speed is achieved , This advantage is virtually unaffected by the inventively embodied switching mechanism, since the only part of the switching mechanism of the connection bracket 20 must be accelerated with, since even a small rotational movement of the Verrastungselementes 17 is sufficient to move the connecting bracket 20 in the Kulisäenführung 18 down freely , The low mass

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the connecting bracket 20 and the coincidence of the direction of action of the return spring 21 with the geometric direction of the connecting bracket 20 also favors the achievement of a high opening speed, since the full tensile force of the return spring 21 is available to accelerate switching contact 2 and connecting bracket 20. The low Ausschaltweg, which is given by the described lever ratio of length lever arm 14 to distance between the rotation axis 12 and contact point 13, also has a positive effect on the achievement of a high contact opening speed. The thermal release is accomplished by means of the thermal release 4, which acts on the lever neck 26 of the half-wave 19 ,,

Claims (2)

23257 1 2 Erfindun g anspru ch 1 .. Miniature circuit breaker in slimline design and low height with a thermal and magnetic release and a mittag mounted two-armed switch contact frontally 'before the extinguishing chamber characterized in that the switching contact (2) has a lever arm (14), the effective length of approximately Half of the distance between switching contact pivot bearing (12) and contact point (13) ent ~
speaks that at this lever arm (14) a connecting bracket (20) engages the switching mechanism, that the contact force by a Schaltkontaktdrehlager in the bearing (12) arranged torsion spring (22) is generated and that the return spring (21) is designed as a powerful spring, the immediate engages on the lever arm (14) via the connection bracket (20) and in its direction of effect coincides with the geometric direction of the connection bracket (20). 2. Miniature circuit breaker in narrow construction according to item 1, characterized in that the connecting bracket (20) is designed as a U-shaped bent wire part massearm. For this 1 page drawings