EP2095388B1 - Double break installation switchgear - Google Patents

Abstract

The invention relates to an installation switchgear (1) with at least one pole current path (2), comprising two stationary contacts (5, 6) and two mobile contacts (8, 9) that are arranged on a mobile contact bridge (7), said contacts forming a double break pole switch with two contacts. The contact bridge (7) is impinged upon by a pusher (12) in the direction of opening (O) and by a contact compression spring (11) in the direction of closure (S). The switchgear further comprises an electromagnetic trigger (13) the striker armature of which, in the event of a short-circuit, strikes the contact bridge (7) open via the pusher (12) in the direction of opening (O) and unlatches the latch point of a switch latch (15) so that the switch latch (15) permanently impinges the contact bridge (7) in a point of attack via an active lever (17) against the force of the contact compression spring (11) so as to open it. The invention is characterized in that the pusher (12), when striking the contact bridge (7) open, entrains the active lever (17) in the direction of its point of attack (24) on the pusher (12) via a dog element (29) so that the trigger path of the active lever (17) is shortened.

Description

The invention relates to a service switching device with a double break according to the preamble of claim 1, as it for example DE 19 540 972 A1 is known.

Generic service switching devices, such as motor protection switch, have at least one Polstrompfad, comprising two fixed contacts and two arranged on a movable contact bridge, movable contact pieces through which a pole switch with two contacts and double interruption is formed The contact bridge is thereby by a pusher in the opening direction and through a contact pressure spring in the closing direction acted upon. Furthermore, generic service switching devices include an electromagnetic release whose armature strikes the contact bridge in the opening direction when a short-circuit current in the Polstrompfad both via the pusher, as well as unlatching the Verklinkungsstelle a switching mechanism, so that the switching mechanism via a knuckle the contact bridge permanently against the contact pressure spring opening acts ,

Immediately after the impact of the contact bridge and thus the interruption of the short-circuit current in the Polstrompfad breaks the electrodynamic recoil of the electromagnetic release together and the contact bridge is acted upon by the force of the contact pressure spring in the closing direction to its closed position.

Due to the greater inertia of the mechanical system formed from the switching mechanism and the active lever, compared with the lower inertia of the armature and the pusher comprehensive mechanical system, the active lever for permanent keeping open of the contacts through the switch lock the pusher movement nacheil. Because after unlatching the switching mechanism, it takes a certain time until the active lever is acted upon by the switching mechanism in the opening direction, and then again passes a certain time until the active lever covered the designated as tripping distance between its rest position and its point of application to the pusher Has. For design reasons, a certain trip path of the action lever is unavoidable, since the pusher and the active lever at rest require a certain amount of play.

Under unfavorable conditions, it may happen that the contacts have already been closed again by the contact pressure spring before the switch lock can cause a permanent opening via the active lever and the pusher. One then speaks of the occurrence of a contact bounce, which is undesirable.

It is therefore an object of the present invention to provide a generic service switching device with improved dynamic behavior in the short-circuit current interruption while avoiding contact bounce.

The object is achieved by a generic service switching device me the characterizing features of claim 1.

According to the invention takes the pusher on a driving part when opening the contact bridge the active lever in the direction of its point of attack on the pusher with, so that the triggering path of the action lever is shortened. If it is then acted upon in the opening direction after unlatching of the switching mechanism of the active lever, it is already close to its point of application to the - then back again by the force of the contact pressure spring in the closing direction moving back - pusher. This allows him to act after unlatching of the switching mechanism with a very small time delay at its point of attack on the pusher and hold it permanently in the open position, before the contact bridge is moved by the restoring force of the contact pressure spring in the closing direction in its closed position, thereby closing the contacts prematurely would. Contact bouncing can be prevented.

According to a particularly advantageous embodiment, the driving part cooperates with the free, the pusher at the point acting on the end of the action lever together. For this purpose, the pusher have a first, a lower stop for the free end of the action lever forming paragraph. The point of action of the action lever on the pusher is then at this first paragraph.

Advantageously, the pusher may have a second, an upper stop for the free end of the action lever forming paragraph. When the pusher through the anchor is beaten in the opening direction, he can then take with the upper stop the free end of the action lever in the direction of the first paragraph out.

It is particularly advantageous if the second paragraph is formed as a bead-like molding on the free, acted upon by the anchor end of the pusher. Further developed, this advantageous embodiment can be characterized in that the pusher is formed in the region between the first and the second paragraph in the form of an approximately cylindrical tube or a cylindrical bolt with a smaller diameter than the rest of the pusher.

Accordingly, in an advantageous embodiment, the active lever at its free, the pusher acting end having a driving part corresponding with the coupling part. This coupling part can be a loop-like surrounding the pusher, U-shaped recess at the free end of the action lever. The recess may at least partially surround the pusher in the area between the first and the second shoulder, so that the range of motion of the action lever is limited to this distance.

Reference to the drawings, in which an embodiment of the invention is shown, the invention and further advantageous refinements and improvements of the invention will be explained and described in detail.

Figur 1:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes mit einem erfindungsgemäßen Drücker in der Ruhestellung,

Figur 2:

eine Schnittansicht des erfindungsgemäßen Drückers gemäß Figur 1,

Figur 3:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes kurz nach Auftreten eines Kurzschlussstroms,

Figur 4:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes bei maximaler Auslenkung der Kontaktbrücke in Öffnungsrichtung,

Figur 5:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes bei rückläufiger Bewegung der Kontaktbrücke in Richtung ihrer Schließ- stellung, sowie

Figur 6:

ein Funktionsschema eines erfindungsgemäßen Installationsschaltgerätes bei dauerhafter Öffnung durch das Schaltschloss über den Wirkhebel.

Show it:

FIG. 1:

a functional diagram of a service switching device according to the invention with a pusher according to the invention in the rest position,

FIG. 2:

a sectional view of the pusher according to the invention FIG. 1 .

FIG. 3:

a functional diagram of a service switching device according to the invention shortly after the occurrence of a short-circuit current,

FIG. 4:

a functional diagram of a service switching device according to the invention with maximum deflection of the contact bridge in the opening direction,

FIG. 5:

a functional diagram of a service switching device according to the invention in case of declining movement of the contact bridge in the direction of its closed position, and

FIG. 6:

a functional diagram of a service switching device according to the invention in permanent opening through the switch lock on the active lever.

In the FIGS. 1 to 6 Each identical or equivalent elements or assemblies are each denoted by the same reference numerals.

The FIG. 1 shows an inventive switching device 1 with a Polstrompfad 2 between an input terminal 3 and an output terminal 4. It could for example be a Polstrompfad a three-pole motor protection switch, the other two Polstrompfade are constructed accordingly.

The pole current path 2 comprises two fixed contact pieces 5, 6 and two movable contact pieces 8, 9 arranged on a movable contact bridge 7, through which a contact point 10 with double interruption is formed. The contact bridge 7 is acted upon by a contact pressure spring 11 in the closing direction, see directional arrow S. By a pusher 12 which engages the contact pressure spring 11 opposite side of the contact bridge 7, this can be applied in the opening direction, see direction arrow O.

The Polstrompfad 2 still includes a thermal release 113 and an electromagnetic release 13 with an armature that hits the contact bridge 7 in the opening direction in the event of a short circuit current occurring in the Polstrompfad 2 due to an electrodynamic recoil over the pusher 12, indicated by the action line 14. At the same time acts the armature of the electromagnetic release 13 in the event of a short circuit on a switching mechanism 15 and unlatched Verklinkungsstelle, indicated by the action line 16, so that the switching mechanism 15 in the unlatched state via an active lever 17, indicated by the action line 18, the pusher 12 permanently in the opening direction the contact bridge 7 acted upon.

The function of the thermal release 113, which also acts in the case of an overcurrent on the switching mechanism 15, indicated by the action line 114, is known in principle and not the subject of the present invention. The thermal release 113 is shown here only for the sake of completeness.

In the mechanical system comprising the switching mechanism 15 and the active lever 17 may be, for example, a toggle lever system with a two-stage latch act. The active lever 17 is designed as a double arm lever whose first, acted upon by the switching mechanism 15 lever arm 171 and the second, cooperating with the pusher 12 lever arm 172 form an obtuse angle with each other and is rotatably mounted in a stationary axis of rotation 173, whereby the active lever 17 as a lever acts.

The mechanical system just described has a certain mechanical inertia, which would, if no further action is taken, after the unlatching a certain time, for example 2 to 5 ms, would pass before the active lever 17 with the free end of its second arm 172 on the Pusher 12 strikes to apply this permanently in the opening direction. In contrast, the time to direct strike of the contact bridge 7 by the armature of the electromagnetic release 13 is much shorter, it is for example only 1 ms. This could, if no further measures are taken, happen that the contact bridge 7 already pressed back by the restoring force of the contact pressure spring 11 back to its original position in the closed position and the contact point 10 is closed again before the effective lever 17 with the free End of his second arm 172 the pusher and thus the contact bridge 7 can act permanently in the open position.

The measures according to the invention, which are taken to prevent this, are described below.

As in the sectional view of FIG. 2 can be seen, the pusher 12 is a total of a longitudinally extending components with approximately a cylindrical or cuboidal basic shape. It comprises two fixedly connected parts, a slide 19 and a striking pin 19 firmly integrally formed on this slider 19.

In a slot-like opening 21 (see FIG. 2 ) in the slide 19, which can be closed down to the narrow side of the slide 19 through a web 25, the contact bridge 7 is guided in its closing - or slidably in its opening direction.

In the opening 21 of the slider 19, an upper stop 23 is formed for the contact bridge 7.

The active lever 17 carries at the free end of its second lever arm 172 a U-shaped recess 174 which surrounds the striker pin 20 of the pusher 12 in an eyelet-like manner. About the U-shaped recess 174 thus the active lever 17 is articulated movably on the pusher 12.

At the transition of the slide 19 on the striker 20, the pusher 12 has a first, a lower stop for the free end 174 second lever arm 172 of the action lever 17 forming paragraph 24.

At the free end of the striker pin 20, the pusher on a second, an upper stop for the free end 174 of the second lever arm 172 of the action lever 17 forming guide shoulder 28. The guide shoulder 28 is designed here as an edge on a attached to the free end of the striker pin 20 driving part 29. The driving part 29 here is a bead-like molding on the free end of the striker pin 20. It could also be a molded plate or a similar construction element.

The effect of this arrangement according to the invention is the following. Because in the Polstrompfad 2 a short circuit occurs, see FIG. 3 Thus, the armature of the electromagnetic release 13 strikes the guide shoulder 28, indicated by the force arrow I in conjunction with the action line 14. By this impulse the pusher 12 is struck in its opening direction O, where he takes over the stop 23, the contact bridge 7, so that thereby the fixed contact piece for 5.6 are separated from the movable contact pieces 8.9 and the contact point 10 is opened altogether. The contact bridge 7 presses in its downward movement while the contact pressure spring 11 together.

By the displacement of the pusher 12 in the opening direction of the guide shoulder 28 arrives in the striker 20 of the pusher 12 in contact with the U-shaped recess 174 at the free end of the second lever arm 172 of the action lever 17, whereby the guide shoulder 28 so the stop for the free end of the second lever arm 172 is.

After opening the contact point 10 of the electrodynamic recoil breaks in the electromagnetic release 13 and the force on the pusher 12 disappears. Due to the inertia of the pusher 12 but this continues its movement in the opening direction O, see FIG. 4 , He takes the active lever 17th via the U-shaped recess 174 at the free end of the second lever arm 172, whereby the active lever 17 is rotated a little way clockwise.

After the contact bridge 7 has reached its maximum deflection in the opening direction, it is pressed by the restoring force of the contact pressure spring 11 again in the closing direction, see FIG. 5 , The active lever 17 initially remains in the position in which he had been brought by the guide shoulder 28 of the slider 12 in its lowest reversing position.

In the restoring movement of the slider 12 thereby approaches the first paragraph 24, which acts on the slider 12 as a lower stop for the U-shaped recess 174 at the free end of the second lever arm 172 of the action lever 17, this free end of the second lever arm 172.

If the slider 12 would now move even further in the closing direction, it would rotate over the first paragraph 24 the active lever 17 counterclockwise again in the direction of its initial position. However, meanwhile, the inertia-related delay shows the switching mechanism 15 has expired, and the switching mechanism exerts a force F on the first lever arm 171 of the action lever 17 via a mechanical device known per se, whereby it remains rotated in a clockwise direction relative to its starting position.

Since the U-shaped recess 174 at the free end of the second lever arm 172 of the action lever 17 at this time already in contact with the first paragraph 24 to the pusher 12, now the pusher 12 by the force F of the switching mechanism 15 via the active lever 17 permanently held in its open position, so that now the contact point 10 is permanently open, see FIG. 6 ,

Without the guide shoulder 28 on the pusher 12 would be at the onset of action of the force F of the switch lock 15, the active lever 17 must turn so far from its rest position that its free end reaches the first paragraph 24 to the pusher 12 in abutment. The consequent additional delay time is avoided by the inventive design of the pusher in cooperation with the U-shaped recess 174 at the free end of the second lever arm 172.

The U-shaped recess shown in the embodiment at the free end of the second lever arm 172 in cooperation with the pin-shaped configuration the pusher 12 in the area of the striker pin 20 is only one of many conceivable ways of realizing the function according to the invention of taking the action lever 17 in the direction of its point of application 24 on the pusher 12. A person skilled in the art will certainly come up with a number of further possible embodiments in order to realize this function according to the invention. For example, the free end of the second lever arm 172 of the active lever 17 may be bar-shaped and extend in a longitudinal direction of the pusher 12 at a corresponding position attached slot between an upper and a lower stop position. The slide can be made in one piece with the striker 20 or the aforementioned slot as an injection molded part. But it could also consist of two parts, in the simplest case of a lower part and a screwed into this lower part cap screw, which then acts as a striking pin with guide paragraph.

LIST OF REFERENCE NUMBERS

1

Service switching device

2

pole current path

3

input terminal

4

output terminal

5, 6

Fixed contact pieces

7

Mobile contact bridge

8.9

Movable contact pieces

10

contact point

11

Contact pressure spring

12

handle

13

Electromagnetic release

14

line of action

15

switch lock

16

line of action

17

active lever

18

line of action

19

pusher

20

striker

21

opening

23

Stop for the contact bridge

24

First paragraph

28

guide shoulder

29

Take part

113

Thermal release

114

line of action

171

First lever arm

172

Second lever arm

173

axis of rotation

174

U-shaped recess

O

opening direction

S

closing direction

I

power Blast

K

force

Claims (7)

1. Service switching device (1) with at least one pole current path (2), comprising two fixed contact pieces (5, 6) and two movable contact pieces (8, 9), which are arranged on a movable contact link (7) and are used to form a pole switch with two contacts and with a double-break function, the contact link (7) being acted upon by a thruster (12) in the opening direction (O) and by a contact pressure spring (11) in the closing direction (S), with an electromagnetic release (13), whose impact armature in the event of a short circuit both strikes the contact link (7) in the opening direction (O) via the thruster (12) and unlatches the latching point of a switching mechanism (15), with the result that the switching mechanism (15) acts on the contact link (7) so as to open it permanently counter to the force of the contact pressure spring (11) via an active lever (17) acting on the thruster (12) at a point of attack, characterized in that the thruster (12), by virtue of a driver part (29), carries along the active lever (17) in the direction towards its point of attack (24) onto the thruster (12) when said thruster strikes the contact link (7), with the result that the release path of the active lever (17) is shortened.
2. Service switching device (1) according to Claim 1, characterized in that the driver part (29) interacts with the free end (174) of the active lever (17), said free end (174) acting upon the thruster (12).
3. Service switching device (1) according to Claim 2, characterized in that the thruster (12) has a first shoulder (24), which forms a lower stop for the free end (174) of the active lever (17).
4. Service switching device (1) according to Claim 3, characterized in that the thruster (12) has a second shoulder (28), which forms an upper stop for the free end (174) of the active lever (17).
5. Service switching device (1) according to Claim 4, characterized in that the second shoulder (28) is a bead-like integral formation on the free end of the thruster (12), said free end being acted upon by the armature.
6. Service switching device (1) according to Claim 5, characterized in that the active lever (17) has an articulation part (174), which corresponds to the driver part (29), at that end of said active lever (17) which is free and acts upon the thruster (12).
7. Service switching device (1) according to Claim 6, characterized in that the articulation part (174) is a U-shaped cutout surrounding the thruster (12) in the form of an eyelet.

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