EP0120836A1 - Electric safety switch for apparatus. - Google Patents

Abstract

In a small-format appliance safety switch with tripping in the event of short-circuit and overcurrent, as well as in a signal switch for actuating and fusing household appliances, office machines, manufacture and other similar devices, the switching and triggering mechanism consists of the combination on the same axis of a fixing body (5) comprising a latching lever (4), a tilting contact pad (6) and a drive lever (14) in operative relationship with several spring elements; this mechanism is in a central position below the control mechanism (1-3), between the swing armature system (8) and the bimetallic strip (10), above the arc extinguishing chamber (12), the (additional) switch contact device (13) and various switch connections (15).

Description

 Electrical device circuit breaker

The invention relates to a single or multi-pole device circuit breaker in small format and narrow construction. Such controls are used in a variety of electrical devices and equipment, such as Household appliances, office machines, control devices for production and assembly machines or the like, built in, in order to provide protection for the relevant circuits and consumers against short-circuit and overload at the same time, in addition to their actual switch function, for which up to now a separate or fuse is provided, which has to be replaced after each defect in a complex and cumbersome manner.

The general structure and function of this device circuit breaker is comparable to the known miniature circuit breaker, which can be actuated manually using a mechanical spring mechanism and actuated manually, electromagnetically and electrothermally

Switch contact arrangement in front of an arc extinguishing device. However, this miniature circuit breaker is usually switched on at all times and should only enable it to be switched on again in the event of a short-circuit or overcurrent trip after the fault has been eliminated.

In contrast, the function of the circuit breaker is a switch element that is frequently operated by hand, which the above-mentioned monitoring functions are additionally entered in order to be able to dispense with the separate need for protection within the switched consumer circuit. - In addition, efforts are made to add a further contact arrangement to the device switch or circuit breaker, which according to its on or off position within a separate signal or control circuit should serve to open the respective switch position and thus the operating state of the electrical device to be switched suitable way, for example optically or acoustically, to show or to control other auxiliary devices corresponding to the switch position or the switching state.

In the much more extensive overcurrent or line circuit breakers of the type mentioned, their equipment with such an auxiliary switch is already known from DE-OS 30 38 511. However, such an extension does not encounter any particular difficulties, since the spatial arrangement of the switching and tripping mechanism in the upper part of the conventional circuit breakers usually allows for no major changes, in this area also an auxiliary contact arrangement of lower load capacity and correspondingly actuated synchronously with the movable main contact to accommodate relatively little space required relatively easily.

On the other hand, in the case of the device circuit breaker in question, if the external dimensions of the circuit breaker are not to differ, or only insignificantly, from the installation size of the previous switch versions without protective measures, the additional accommodation of the switchgear, release elements and extinguishing device in the available switch interior alone presents considerable difficulties . This fact also explains why the designer did not initially consider equipping the circuit breaker with another contact arrangement. The present invention is therefore based on the object to develop a circuit breaker, the protective devices against short circuit and overload can be accommodated in connection with a changeover contact arrangement for signal or control purposes by a suitable design and arrangement of all components within the specified dimension range of the normal built-in switch design.

This object is achieved in a device circuit breaker according to the preamble of claim 1 according to the invention in that the entire switching mechanism from the combination of a clamping body with several functional approaches, a V-shaped flat release lever, the movable pivoting contact piece and one arm

Driver lever for the signal switch composes, which are arranged at a central location for themselves pivotable about a common axis of rotation, functionally interlock and partially supported against each other and overall against the housing by means of individual spring elements.

Due to this particular training and summary of the switching mechanism and its central arrangement with a common pivot point, it is now possible to distribute the operating and actuated elements of the entire circuit breaker to a very limited space in the plane around such a switching mechanism and to functionally function with it couple.

Accordingly, the switching mechanism is made up of a total of four individual lever members mounted on the switching housing and pivotable about the same axis of rotation, including three further spring elements. The basic element here is the clamping body formed from insulating material with the function protruding from its three corner points on the front approach, which is rotated by the leg spring wound around a flange and supported against the housing in the direction of the switch-off position. In the spatial area between these three functional approaches, both the unlatching lever and the movable swivel contact piece are arranged as stamped parts, as is the driver lever, which is again made of plastic, for the signal switch. The V-shaped, flat release lever works together with its bow-shaped, extended latch leg with the upper functional shoulder, against which it is also supported with a counter leg under pressure from the latch spring. The swivel contact piece mounted on it is pressed on its switching arm by the spring, which is supported in front of the right functional approach and causes the contact pressure, into the more extensive guide cut of the left functional approach, which then may suddenly act on the switching arm when the switch is triggered due to this guide play. In addition, the electrical supply is via a flexible strand, which is conductively connected to one arm of a T-shaped configuration of the swivel contact in the area of its mounting.

With this composition, in comparison with the known spring mechanisms, in which the spring elements in question are each individually supported on the housing, the combined

(Storage and) suspension of the release lever as the swivel contact piece by means of the associated pawl and contact pressure spring compared to the same movable clamping body de switching mechanism achieved with advantage that for these two elements, on the one hand, a smaller spring travel is required and, on the other hand, a greater spring consistency is thereby ensured.

On the axis of rotation of these three lever members is still the loosely attached driver lever for the contact arrangement of the signal switch, which in the course of the on or off rotation) of the clamping body by its right Functional approach and with effect on the changeover (middle) contact is pivoted into one or from the left functional approach to the other switching position. This overall arrangement of the switching mechanism is then simply moved freely within the switch assembly by means of the cover cap which is plugged on and which positively slides over the end face of the common axis of rotation.

According to the feature of claim 2, the on and off actuation of the circuit breaker takes place with the help of an outwardly from the housing and through its cover cap protruding toggle which is pivotally mounted on an axle shoulder of the housing and against the restoring force of the leg spring contained by its shaft . This control knob is coupled to an inward-extending extension in the manner of a knee with the H-shaped connecting member, in the free end of which a push pin is inserted transversely. The push pin acts on the upper functional approach of the clamping body during the activation process and adjusts the entire switching mechanism against the restoring force of the leg springs of the control knob and clamping body beyond a dead center. This is followed by the release spring-loaded release lever, which has a locking groove on the inside of the bow-shaped extension of the relevant latch leg, in which the pressure pin can get caught. In addition, in the case of free triggering when the control knob springs back, a forced guidance of the knee joint connecting element is achieved, as a result of which the return spring necessary for returning the push pin into its latching can be saved without this.

For the feature of claim 3, the electromagnetic release member of the switch is designed as a hinged armature system, with its magnetic yoke enclosing the magnetic core with the excitation winding on the left in a U-shaped manner Narrow side of the housing is inserted into an appropriate profile and is held therein. In addition, the folding armature of this release element, which is mounted on an extension of the outer magnetic yoke leg and is tensioned from there by means of a tension spring, has an extension which extends into the functional area of the adjacent switching mechanism in order to trigger a short-circuit release of the switch to the second one which is adjusted by the tensioned mechanism To strike the latch leg of the release lever. This arrangement also results in a defined assignment of the hinged armature to the magnetic yoke, which makes any adjustment and subsequent correction unnecessary with regard to the exact dimensioning of the air gap.

According to the feature of claim 4, the bimetallic strip-shaped electrothermal release element of the switch for protection against overload is arranged next to the switching mechanism on the right narrow side of the housing. Here, the bimetallic strip has a setting above the plug-in holder in a corresponding profile of the housing the exact trigger value serving and therefore accessible from the outside adjustment and continues down into one of the outer connecting lugs. In addition, the adjustment arrangement welded to this connecting lug is made in one piece with one of the arc guide plates for the quenching device described below. On the other hand, the bimetal strip with its free actuating end in the switched-on state faces the bow-shaped, elongated latch leg of the unlatching lever of the switching mechanism in order to initiate the triggering of the switch from this point after a corresponding deflection due to the load-dependent curvature of the bimetal strip.

With regard to the individual features of claims 5, 6 and 8 is by the fixed contact piece and the movable Swivel contact piece formed contact interruption arcing directly in front of the quenching chamber for the resulting switching, which in turn extends spatially under the hinged armature system and is therefore classified next to the signal switch in the lower part of the switch housing. In the extinguishing chamber provided with gas outlet slots there are two or more ferromagnetic extinguishing plates which are inserted parallel to each other in longitudinal grooves on the rear wall of the housing. In addition, an arc guide plate that is brought forward into the contact area is provided on both long sides of these quenching plates. Of this, one baffle forms with its front end the fixed contact of the switching path and at the same time the connection point for the end of the field winding of the hinged armature system, while the other baffle - as already mentioned - integrally with the adjustment device for the bimetal strip mechanically and electrically in direct connection with de relevant connection flag is. It is also important that the contact pairing is provided with silver overlay against silver-cadmium oxide, which ensures a high level of arcing, erosion and welding resistance of the contact arrangement with a very low voltage drop, which in addition results in the sudden separation by the triggering Clamping body of the switching mechanism has an advantageous effect. Overall, it is achieved with the design provided here that the V-shaped blow loop formed by the contact arrangement itself drives the arc which arises when the switching path is opened extremely quickly from the two contacts and along both guide plates into the quenching chamber. In its area, the sheet is then divided, cooled and deionized by means of the sheets, after which the air cushion in front of it, like the gases produced by it, can escape safely into the open.

According to the features of claims 7 and 8 sets you between the quenching chamber and the connection bracket for the bimetallic strip signal switcher composed of two fixed contact pieces inserted into the housing base and with their connecting lugs reaching outwards, between which the switch contact piece designed as a spring-loaded flip-flop is mounted on the bend of a further connecting lug engaging in the housing. In addition to its double contact rivet, this flip-flop is provided with an actuation projection, which is gripped in a fork-like manner by the driver lever of the switching mechanism in order to synchronize it accordingly, in accordance with the switch-on and switch-off or triggering operation thereof, but electrically independently of the actual switching and monitoring function of the circuit breaker alternatively, to be switched from one to the other switch position in order to suitably signal the main operating state or existing operating state or to control other processes depending on this.

The manufacturing and assembly matters of the device circuit breaker according to the features of claims 9 and 10, the individual parts thereof can be used and held by hand and partly even mechanically, either individually or as preassembled assemblies, functionally in the correspondingly designed and prepared insulating housing. In addition, this fully assembled housing is designed in its spatial form as an insert, which can finally be provided with an insulating material cap encompassing it on both narrow sides. This cap fully covers the entire assembly area of the switch on one side and acts as a safeguard against loosening of the parts used as well as a contactor and protection against contamination. On the other hand, it enables unhindered access by the control knob on the front of the switch to be installed and leaves the various connection lugs freely accessible on the underside of the switch, so that, in the fully pushed-on position, it can be elastically and detachably moved over one on the rear of the housing insert. to catch the goat. Furthermore, the cap is provided on the outside on its two narrow sides with molded spring tongues which, in cooperation with the front panel, enable a detachable mounting of the switch in a corresponding section of the electrical appliance in question or elsewhere.

The subject matter of the invention is explained in more detail in the various functional sequences with reference to a device circuit breaker with signal switching shown as an exemplary embodiment in the accompanying drawing and as a supplement to the above explanations. This shows:

Figure 1 shows the overall view of the switch in the ON position with the cover cap cut.

2 shows a longitudinal section through the switch in the area of its switching mechanism; and FIG. 3 shows the cross section at the level of the rotary bearing of this switching mechanism.

As can be seen from the enlarged illustration of FIG. 1 of the drawing for the original version on a scale of 2.5: 1, the switching mechanism composed of several lever and spring members is located approximately in the middle of the flat switch. According to the further construction of the switch, this switching mechanism is located between the electromagnetic release element arranged on the left switch side and the electrothermal release element arranged on the right switch side. Furthermore, the switching mechanism is below the outward-reaching operating handle, as well as above the contact and extinguishing device of the switch, the contact arrangement of the signal switch and the various external connections.

The switching on by means of a toggle actuation of the control knob 1 and against the force of its return spring of the device circuit breaker takes place in the manner of a knee joint coupling via the connecting member 2. This member 2 is guided with its transverse pressure pin 3 through the bow-shaped port set of the unlatching lever 4 and meets with the pin 3 on the functional approach of the clamping body 5 of the switching mechanism located above. When it is adjusted in the opposite direction of rotation and against the force of its return spring, the unlatching lever 4 embedded in the tensioning body 5 on the same axis of rotation follows the pressure pin 3 under the action of its ratchet spring. In the course of this movement, the pressure pin 3 hooks under the bow-shaped extension of Unlatching lever 4, with which the switching mechanism is in the tensioned state after the operator-side overturning of the dead center of the knee joint coupling, namely against the force of the leg springs of the tensioning body 5 and operating knob 1. At the same time, with the accompanying adjustment of both pawl legs of the unlatching lever 4 into their respective triggering position, the pivoting contact piece 6 of the contact arrangement of the contact body 5, which is still embedded in the clamping body 5 of the switching mechanism

Switch in conductive contact with the fixed contact 7 has been adjusted. After contact has been made, a sufficient overstroke in the rotary movement of the left-hand functional approach leading the contact arm 6 causes the required contact pressure to be achieved by means of the helical spring which is supported between the contact arm 6 and the right-hand functional approach of the tensioning body 5.

If a short-circuit current flows through the switch as a result of a defect in 7 to 10 times the nominal current, it excites the hinged armature system 8 via the windings of the winding, whereupon the magnet armature 9, which is loaded by tension spring, and the entire switching mechanism via the leg of the release lever 4 opposite it opens or triggers. Accordingly, the other leg of the unlatching lever 4 is the one with the pressure pin 3 under its bow-shaped Extension latched actuators free, whereupon the spring-loaded ßedienungsknebel 1 returns to its off position and the spring-loaded switching mechanism by means of its clamping body 5 snaps back into the corresponding position. In this process, the two spring elements (from FIGS. 1 and 5) initially act together on the clamping body 5 until it has completely opened the contact path 6/7 when it strikes an existing housing stop; then only the leg spring of the control knob 1 leads it back to its original position. Furthermore, in the course of the switching-on process, the clamping body 5 has been given an overstroke whose left-hand functional approach can act suddenly on the contact arm 6 at the moment of the short-circuit triggering and consequently bring about an extremely fast and effective contact separation, which prevents, among other things, contact welding.

If, on the other hand, a greater overcurrent flows through the switch due to a prolonged overload of the consumer circuit to be monitored, this fact has an effect on the thermal release, which is electrically connected in series, instead of energizing the relevant short-circuit monitoring element 8. Here, the current of the connected consumer flows through a resistor, which heats the bimetal strip 10 more or less and accordingly quickly and strongly causes a curvature towards the switch. If this curvature path is greater than the value which was set by means of the adjustment device 11 provided in the connection and mounting area of the bimetallic strip 10, the strip 10 strikes the free end of the bow-shaped extension of the unlatching lever 4, pushing it out of the latching position the push pin 3 of the actuators and thus initiates the triggering process already described for the short circuit. - In both cases the free trip entered into the switching mechanism that the switch cannot be switched on again as long as the cause for its switching off has not been eliminated.

When the device circuit breaker is switched off manually under load, as well as when it triggers a short circuit or overcurrent, an energetic switching arc is formed at the contact interruption point 6/7. Due to the V-shaped blow loop formed by the swivel contact piece 6 with the plague contact 7 and its connection point, this arc is quickly driven from the point of origin into the subsequent quenching chamber 12. He remains ver with his one foot point in constant contact with the guide plate leading from the fixed contact 7 further into the extinguishing chamber 12, while his other foot point is made much easier by the extension of the opposite guide plate into the ϊfah range of the swivel contact piece 6. Then the arc column is split into partial arcs when it strikes the end faces of the three ferromagnetic quenching plates within the chamber 12, cooled between the plates and deionized. Thereafter, the arcing gases generated, as well as the air cushion produced in front of the arc, can escape safely and safely through the ventilation slots provided between the metal sheets in the housing wall.

Ben additional signal switch of the device circuit breaker, its toggle spring-loaded center contact 13 by the clamping body 5 of the switching mechanism (together with the unlatching lever 4 and the pivoting contact piece 6) on the same axis of rotation entrained driving lever 14 corresponding to the switch-on or switch-off or release movement of this Clamping body 5 mechanically brought into (snap) contact with one or the other fixed contact piece. In this simple way it is possible to be in exact sync to switch additional circuits to the operating state of the switched and simultaneously monitored electrical device in a confined space, with which, for example, the respective switch position or the existing operating status can be optically signaled or auxiliary devices dependent thereon can be controlled accordingly.

Claims

Claims

1.Single-pole or multi-pole device circuit breaker in small format and narrow construction with a mechanical spring mechanism for actuating a switch contact arrangement which can be switched on by hand and can be triggered manually, electromagnetically and electrothermally in front of an arc extinguishing device and in conjunction with an additionally integrated signal changeover switch, characterized in that the entire Switch mechanism composed of the combination of a clamping body (5) with several functional approaches, a V-shaped flat release lever (4), the movable swivel contact piece (6) and a one-armed driver lever (14) for the signal switch (13), which are located at a central point for are arranged to be pivotable about a common axis of rotation, functionally interlocking and partially supported against one another and overall against the housing by means of individual spring elements.

2. Device circuit breaker according to claim 1, characterized in that the toggle pivotally mounted on the housing against the force of a return spring control knob (1) like a knee via an H-shaped connecting member (2) with a transverse push pin (3) loose with one of the functional approaches of the clamping body ( 5) is coupled.

3. Device circuit breaker according to claim 1, characterized in that the tension spring-loaded hinged armature (9) of the on one narrow side next to the switching mechanism and below the control knob (1) and designed as a hinged armature system (8) formed electromagnetic release member with an extension beyond its magnetic yoke in the release area of one of the legs of the release lever (4) protrudes.

4. Circuit breaker according to claims 1 and 3, characterized in that the bimetallic strip (10) of the electrothermal tripping element arranged on the other narrow side next to the switching mechanism is fixed with one end (at 11) and can be readjusted in the housing and for tripping with its free actuating end of a bow-shaped extension on the other leg of the unlatching lever (4).

5. Device circuit breaker according to claims 1, 3 and 4, characterized in that the switching arm of the swivel contact piece (6) electrically connected to the free end of the bimetallic strip (10) via a flexible wire and that directly to one end of the excitation winding of the hinged armature system (8 ) connected fixed contact piece (7) when the switching path is closed, a V-shaped blow loop is formed when it is opened on the switching arc running from the point of interruption into the quenching chamber (12).

6. Device circuit breaker according to claims 1 and 3 to 5, characterized in that the obliquely extending under the hinged armature system (8) and provided at the rear with gas outlet slots quenching chamber (12) is equipped with a plurality of ferromagnetic quenching plates held parallel to each other on the housing, the two lateral Baffles, on the one hand, form the fixed contact point (7) on the front side and, on the other hand, are in object-conductive connection with the connection bracket (11) for the bimetal strip (10).

7. Circuit breaker according to claims 1 and 6, characterized in that the contact pieces of a between the arcing chamber (12) and the connection bracket (11) for the bimetallic strip (10) arranged signal switch with their connecting lugs (15) reach outwards, the switching contact piece (13), which is designed as a spring-loaded tilting member, between the two fixed contact pieces being operable via the driving lever (14) by the respective rotary movement of the clamping body (5) of the switching mechanism.

8. Circuit breaker according to claims 1 to 7, characterized in that the current supply within the switch from the one terminal lug (15) electrically in series via the field winding of the hinged armature system (8) by the two switch contact pieces (6 and 7) immediately before the extinguishing chamber (12) formed interruption point and the bimetallic strip (resistance) (10) to the other terminal lug (15), for which purpose the additional signal switching device has its center contact (13) according to the respective switching state, but electrically independent, from one to the other other plague contact connection (15).

9. Circuit breaker according to claims 1 to 8, characterized in that the individual parts of the operating and switching mechanism, the hinged armature system with its connecting lug, the bimetallic strip with its connection and adjustment bracket and, partly in connection with the latter, the arcing and - Extinguishing plates, and also the contact arrangement of the signal changeover switch with its connections, can be mounted overall on or within the design of a housing insert provided for this purpose, which in turn is to be provided by means of an insulating material cap that surrounds it on the two narrow sides and fully covers the assembly side, the top side has an opening for reaching through the control knob and takes over the (partly movable) mounting of the parts used as well as the contact protection of the switch.

10. Circuit breaker according to claim 9, characterized in that the releasably locking with the housing insert on the back of the insulating cap is provided on its two narrow sides with molded spring tongues for holding the switch in a corresponding device cutout.