EP0091040B1 - Protective excess current circuit-breaking switch - Google Patents

Description

The invention relates to an overcurrent protection switch with the features of the preamble of claim 1.

Such a switch is known from DE-B-2 132 738. By means of a toggle lever element, the movement of the actuating element is transmitted to a pivotable contact arm which, together with a contact fixed to the housing, forms the main contact of the switch. A restraining stop cooperating with the actuating element ensures that the contact elements close suddenly (momentary activation) when the contact is switched on. For this purpose, the contact arm is locked during the closing movement before the main contact is closed by means of the retaining stop. The latter is part of a retaining pawl which is essentially longitudinally displaceable in the closing direction and which can be locked behind a housing projection in the retaining position. When the actuating element is brought into the incision end position, the retaining pawl is disengaged by the actuating element acting on it, whereby the contact arm is released from the restraining stop for the abrupt closure of the main contact.

A disadvantage of the overcurrent protection switches described is the direct, articulated connection of the retaining pawl to the contact arm by means of a bolt. Relatively large masses are thus firmly coupled to the contact arm, which has a negative influence on the switching behavior. In particular, when several overcurrent protection switches are coupled to multiple switches with interconnected switching mechanisms, rapid, high breaking capacities can no longer be triggered. In addition, in the known construction of the overcurrent protection switch, there is a risk of false tripping due to fluttering movements of the armature of the magnetic release.

The invention has for its object to design a switch of the type mentioned in such a way that it has a defined switching behavior with a compact design and uncomplicated handling. This object is achieved by the characterizing features of claim 1.

According to the invention, the retaining pawl is a separate component that is decoupled from movement in the opening direction by the contact arm. With its restraining stop, it engages under the contact arm during the closing closing movement between its contact and joint end. This ensures that the torque is switched on, but in particular during the opening movement, the contact arm can freely move upwards into its open position. The mass carrier unit of the retaining pawl cannot have a negative effect on the switching time. The switching behavior is characterized by a defined short switch-off time. Since, in combination with the specified feature, the magnetic yoke of the overcurrent release also protrudes beyond the coil end on the side of the hinged armature and has an L-shaped shunt bend overlapping the hinged armature, the risk of false triggering due to fluttering movements of the armature of the magnetic actuator is also avoided. The hinged anchor “sticks” to the shunt bend in its rest position until the force exerted on it by the coil flow is greater than the holding force of the shunt bend. False triggers and their negative influence on the switching behavior are thus avoided, which is further supported by the characterizing feature of claim 2.

The switching behavior of the overcurrent protection switches according to the invention, which is defined to a high degree, allows a number of such switches of the same type to be coupled to one another in a simple manner. This is done according to claim 3 via a coupling lever in each overcurrent protection switch, which is effectively connected to the contact arm. The effective end of the coupling lever acts on the locking lever of the knee joint in the release direction. When at least two such overcurrent protection switches are coupled, the coupling levers are each connected to one another via a coupling axis engaging in the adjacent switch. In the event of an overcurrent tripping of at least one switch, all other switches in the multiple unit are triggered automatically. Since, apart from the coupling levers and the axis, no other parts, such as the retaining pawl or the like. must also be accelerated, the triggering takes place in a defined short switching time even when several switches are coupled.

Claim 4 teaches a particularly simple and functional way of arranging and guiding the restraint stop, it being emphasized that the restraint stop is released directly and thus in a structurally simple manner by the actuating element itself.

Claims 5-7 ensure that when the switch is switched off or overcurrent tripped, the retaining pawl jumps back into its retaining position. The spring exerts a torque on the retaining pawl above the projection, which it engages under, such that when the main contact opens, the retaining pawl securely latches behind the housing projection that holds it in the retaining position and simultaneously exerts a system pressure directed against the actuating element.

Claim 9 enables the switch lock according to the invention to be used in different switch housings, which simplifies the storage of components.

Claim 10 is concerned with a special, particularly functional design of the transmission of the axial movement of a push button on the stretching lever.

Claim 11 enables the control of an auxiliary circuit switch known per se.

• Fig. 1 eine Gesamtansicht zweier, aneinander gekoppelter Schalter,
• Fig. 2 eine Innenansicht des Schalters in der Einschaltstellung,
• Fig. 3 eine Innenansicht in der Ausschaltstellung,
• Fig. 4 einen Querschnitt durch zwei gekoppelte Schalter mit der Darstellung der Kopplungsteile,
• Fig. 5 das Schaltschloss - schematisch in der Aus-Stellung,
• Fig. 6 das Schaltschloss - schematisch in der Stellung kurz vor der Momenteinschaltung der Hauptkontakte,
• Fig. 7 das Schaltschloss - schematisch in der Ein-Stellung,
• Fig. 8 eine Ansicht der das Schaltschloss und den Magnetauslöser umfassenden einstückigen vorgefertigten Baueinheit,
• Fig. 9 einen Schalter mit als Druckknopf ausgebildetem Betätigungselement,
• Fig. 10 eine weitere Bauform eines Schalters mit Kipphebelbetätigung.

The invention is described in more detail with reference to several exemplary embodiments shown in the figures of the drawing. It shows:

• 1 is an overall view of two coupled switches,
• 2 is an interior view of the switch in the on position,
• 3 is an interior view in the off position,
• 4 shows a cross section through two coupled switches with the representation of the coupling parts,
• 5 the key switch - schematically in the off position,
• 6 the switch lock - schematically in the position shortly before the main contacts are switched on,
• 7 the key switch - schematically in the on position,
• 8 is a view of the one-piece, prefabricated structural unit comprising the switching lock and the magnetic release,
• 9 shows a switch with an actuating element designed as a push button,
• Fig. 10 shows another design of a switch with rocker arm actuation.

The key switch (Fig. 2, 3, 5 to 7)

The switch lock is operated manually via the rocker arm 1. This is rotatably mounted in the two housing halves with its pins 3 on both sides. In the drawing, the lower housing part 2 is shown. A joint 4 is arranged in the inner region of the rocker arm. The toggle lever element, consisting of the first stretching lever 5 and the second stretching lever 6, is mounted on it, which in turn is rotatably connected by means of the knee joint 7. The lower end of the toggle lever element is articulated to the contact arm 9 via the bolt 8. The stretching lever 5 is approximately triangular and has a further pivot point 10 in the third corner, in which a latching lever 11 is mounted. The latch lever can get caught with a catch 12 of the extension lever 6, so that the knee joint 7 becomes stiff. The latched knee joint is shown in FIG. 2 and in FIGS. 5 to 7, whereas in FIG. 3 the latching is released. As soon as the knee joint 7 is stiff, the contact arm 9 can be pivoted about its pivot point 13 when the rocker arm 1 is actuated manually. Depending on the direction of actuation of the rocker arm, the contacts are opened or closed.

In the switched-on position, the force component is oriented in such a way that a left-turning torque is exerted on the rocker arm 1. By the stop 14 in the housing, the rocker arm 1 comes to rest in this position. The key switch is cocked. The force component of the tensioned switch lock is greater than the counterforce of the torsion spring (not shown) on the rocker arm 1. When operated manually, the knee joint 7 remains locked. The contacts are influenced solely by the rocker arm positions.

The switch lock is triggered automatically via the magn.-hydr. Trigger 15.

When there is a corresponding overcurrent, the hinged armature 16 picks up and rotates about the pivot point 17. The arm 18 of the hinged armature 16 presses against the latching lever 11 and moves it upward. The latching between the latch lever 11 and the catch 12 of the extension lever 6 is released and the knee joint 7 collapses. This is caused by the torsion spring 19, which moves the contact arm 9 upwards by its spring force.

The magn. The circle of the magnetic hydraulic release has a magnetic yoke 20 which is provided with a shunt bend 22 connected to the magnetic core 21. In the middle area, the yoke carries lateral tabs in which the parts of the key switch are stored and guided.

The magnetic flux that forms in the magnetic coil when current flows through it also branches in the rest position via the shunt bend 22 and the hinged armature 16. The rest of the magnetic flux goes from the hinged armature 16 to the magnet core 21. The hinged armature 16 can be selected by corresponding cross-section of the shunt be fixed in its rest position more or less long. Only with larger currents does the pulling force between the hinged armature 16 and the magnetic core 21 predominate and the hinged armature 16 can tear away from its contact point on the shunt bend 22.

The moment switching on of the contacts:

When the rocker arm 1 is switched on, the contact arm 9 is held shortly before its final closure and released momentarily after the switch lock is tensioned.

• - Rückhalteklinke 23
• - Druckfeder 24
• - Bolzen 25
• - Bolzen 26
• - Rückhalteanschlag 28

The following parts do this:

• - Retaining pawl 23
• - compression spring 24
• - bolt 25
• - bolt 26
• - Restraint stop 28

The retaining pawl 23 is rotatably and displaceably mounted on the bolt 26. The retaining pawl 23 is pressed against the bolt 25 by the compression spring 24 (FIG. 5). If the key switch is moved to the switch-on position, the toggle lever element leads the contact arm 9 downwards. This movement is slowed down by the restraining stop 28. The bolt 8 moves freely and unhindered in the backdrop 27. This position is shown in FIG. 7. When the rocker arm 1 moves further, the main contact 48 cannot close. The restraint stop acts like a pivot point, so that the contact arm 9 moves at its pivot point 13 by means of the bearing groove 57. At the same time, however, the joint 4 of the rocker arm comes into contact with the release lug 29 and thereby moves the retaining pawl to the left until the locking on the bolt 25 is released. The main contact closes momentarily. The retaining pawl 23 is carried along by the retaining stop 28 from the contact arm 9 in the closing direction 51 and can only return to their locked position after opening the contacts.

The coupling mechanism (Fig. 2, 3 and 4 and Fig. 1):

The coupling of several individual devices to a functional unit takes place both with manual actuation and with overcurrent tripping.

The coupling for manual actuation takes place on the rocker arms 1 by interposing the coupling piece 30. The parts mentioned are connected to one another by suitable mechanical elements. This is shown in FIG. 1 using a two-pole device consisting of two individual devices (device 31 and device 32).

The coupling for the overcurrent release is established by the coupling lever 33 and the coupling axis 34. The coupling levers 33 of the devices lying next to one another are connected to one another by the coupling axis 34, which projects through the housing side walls. At the pivot point 36, the coupling lever 33 is mounted in the housing. By means of the compression spring 35, it is moved downwards in a clockwise direction and comes to rest with its leg 37 on the bolt 8. Now triggers a switch automatically by its magnetic trigger, then the bolt 8 moves up with the contact arm 9 and takes the coupling lever 33 with it.

• - Festkontakt-Öffner 39 (von der Aus-Stellung betrachtet),
• - Festkontakt-Schliesser 40 (von der Aus-Stellung betrachtet),
• - Kontaktfeder 41 in Schnappausführung,
• - Betätigungshebel 42.

Whose leg 37 strikes during its movement against the L-shaped tab of the latch lever 11 (Fig. 4) and thereby releases the locking of the knee joint 7. However, since the coupling axis 34 couples the coupling lever 33 to one another, the neighboring devices also come into operation. Auxiliary contacts are also inserted into the housing parts (Fig. 2 and 3). In the example shown, it is a changer with the following parts:

• Fixed contact break contact 39 (viewed from the off position),
• - Fixed contact make contact 40 (viewed from the off position),
• - snap spring contact spring 41,
• - operating lever 42.

The operating lever 42 has two attachment points. The stop point 43 is moved downward by the contact arm 9. With it, the stop point 44 moves against the contact spring and causes it to snap.

The current flow:

The current flows from the connection 45 to the coil of the magnetic hydraulic release 15, from this via a wire to the contact arm 9 and then via the contact pair to the connection 46. In the area of the contacts, quenching plates are arranged. The arc gases can be blown out via appropriate channels in the housing.

Fig. 8 shows the switch lock with magnetic release again, which can be used as a prefabricated component in the housing of different dimensions and designs (Fig. 9 and Fig. 10). In the exemplary embodiment shown in FIG. 9, the actuating element is a push-pull button 60, which is arranged in a screw sleeve 61 on the upper side 62 of the housing so as to be axially displaceable. Its inner end 63 interacts via an arm 64 by means of a pin 66 guided in an elongated hole 65 with a pivot lever 67 which converts the axial button movement into a pivoting movement and is pivotably mounted on an axis 68 fixed to the housing and with the first stretching lever 5 via a joint 69 connected is.

The unit 58 corresponds in function and components to the switch already described.

Auxiliary contacts 38 are arranged on the lower side of the housing facing away from the actuating element (push-pull button 60) and are actuated via an actuating lever 70 which interacts with the contact side of the contact arm 9.

The assembly 58 is also used in the exemplary embodiment shown in FIG. 10 of a switch which can be placed on a switch rail, the actuating element also being designed as a rocker arm as in the first exemplary embodiment explained. However, the connection elements 71-74 for the main and auxiliary circuit are in the side area of the housing.

Claims (14)

1. Excess-current circuit-breaker

1. with an actuation element for manual switching on/off,

2. with a toggle lever element (extending lever 5, 6, knuckle joint 7) which is articulated at the housing-internal end of the actuation element and can be locked for instance in extended position by means of a latching lever (11) and

2.1 is pivotably connected on the contact side to a swivelling contact arm (9) for opening and closing of the main contact (48), and

2.2 in the case of excess current, can be moved from its locked extended position into its bent position by releasing the latching lever (11) by means of impingement by the hinged armature (16) of a magnetic overcurrent trip (15),

3. the contact arm (9) being locked in the switching-on closing movement before closure of the main contact (48) by means of a retention stop (28) which

3.1 is a component part of a retention latch (23) which is longitudinally displaceable substantially in closing direction (51) and

3.1.1 can be locked in retention position (Figs. 5, 6) behind a housing projection (bolt 25) and

3.1.2 can be unlocked when bringing the actuation element into the switching-on end position by impingement of the actuation element (rocker lever 1), whereby the contact arm (9) is released by the retention stop (28) for the abrupt closure of the main contact (48),

characterized by the combination of the following features:

4. the retention latch (23) is a separate component decoupled in movement from the contact arm (9) in its opening direction and engages by its retention stop (28) underneath the contact arm (9) in the switching-on closing movement, between its contact end (49) and its joint end (50), and

5. the magnetic yoke (20) of the overcurrent trip (15) extends beyond the coil end on the side of the hinged armature (16) and has an L-shaped shunt-wound bent-off portion (22) engaging over the hinged armature (16).

2. Excess-current circuit-breaker according to Claim 1, characterized in that the hinged armature (16) lies in rest position against the side of the shunt-wound bent-off portion (22) facing the coil.

3. Excess-current circuit-breaker according to Claim 1 or 2, characterized in that at least two such excess-current circuit-breakers (31, 32) (Figs. 1, 4) can be coupled, each having a coupling lever (33) in effective connection with the contact arms (9) with its effective end (limb 37) engaging the locking lever (11) of the knuckle joint (7) in release direction, one coupling lever being connected, for engagement in the excess-current circuit-breaker (32) which is arranged alongside the one breaker (31), to the coupling lever (33) thereof via a coupling pin (34).

4. Excess-current circuit-breaker according to one of the preceding claims, characterized in that the retention latch (23) extends substantially along the toggle lever element (extending lever 5, 6) and has on its main contact-sided end (52) the retention stop (28) engaging underneath the contact arm (9) and on its actuation end (53) a trip lug (29) which can be shifted laterally through the inner end (joint 4) of the actuation element (rocker- lever 1).

5. Excess-current circuit-breaker according to one of the preceding claims, characterized in that the retention latch (23) has in its middle region (54) a substantially L-shaped clearance (55), in whose catch L limb (56), which runs substantially at right- angles to the closing direction (51), the housing projection designed as a bolt (25) lies in the retention position (Figs. 5, 6).

6. Excess-current circuit-breaker according to one of the preceding claims, characterized in that the retention latch (23) is pretensioned by means of a spring (24) in the direction of the actuation element (rocker level 1).

7. Excess-current circuit-breaker according to one of the preceding claims, characterized in that the spring (compression spring 24) engages underneath a projection (58) protruding from the retention latch (23) in the direction of the catch L limb (56) of the clearance (55).

8. Excess-current circuit-breaker according to one of the preceding claims, characterized in that the contact lever (9) is mounted on a housing pin (rotation point 13) by means of a bearing groove (57) running substantially in closing direction (51) in the joint end (50).

9. Excess-current circuit-breaker according to one of the preceding claims, characterized in that the latching mechanism (essentially 5-13, 23-29) and the trip (essentially 15-22) can be used as a standard prefabricated unit (58) in housings of different design and function.

10. Excess-current circuit-breaker according to one of the preceding claims, characterized in that the handle of the actuation element is designed as an axially shiftable pushbutton (60), the inner end (63) of which is connected to a swivelling lever (67) actuating the first extending lever (5) of the unit and converting the axial movement into a swivel movement.

11. Excess-current circuit-breaker according to one of the preceding claims, characterized in that one or more auxiliary contact switches (auxiliary contacts 38, fixed NC contact 39 and fixed NO contact 40) are arranged in the housing side facing away from the actuation elements and can be actuated by means of an adjusting lever (actuation lever 42) interacting with the contact side of the contact arm (9).

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