EP0371416B1 - Thermal relay - Google Patents

Abstract

The invention relates to a thermal relay having bimetal triggers, mounted in a housing with at least one side which can be closed off by means of a lid, and an auxiliary switch with switching rocker and a multi-part transmission device responding to the bimetal deflection, actuating the auxiliary switch and having a compensation bimetal rod for the ambient temperature, as well as operating elements in the form of an adjustment member for the current by changing the triggering path of the bimetal triggers, of a test member for testing the switching function of the auxiliary switch and of an operating member for the resetting of the auxiliary switch into the initial position manually or automatically, all the operating elements (600, 620, 650) being fastened on a carrier plate (60) which can be pushed together with the operating elements into the housing equipped with the auxiliary switch components, the transmission device and the bimetal triggers from the side which can be closed off by means of the removable lid (13). <IMAGE>

Description

The invention relates to a thermal relay with bimetallic triggers accommodated in a housing with at least one side that can be closed by means of a cover, and an auxiliary switch with rocker switch and a multi-part transmission device that responds to the bimetal deflection and actuates the auxiliary switch with a compensation bimetal rod for the ambient temperature, and operating elements in the form of a setting element for the current by changing the release path of the bimetallic release, a test element for testing the switching function of the auxiliary switch and an operating element for resetting the auxiliary switch to the starting position by hand or automatically.

Thermal relays, also known as thermal overcurrent relays or overload protection relays, serve as reliable motor protection in the event of overload and phase failure by switching off the motor. The essential components of such a thermal protection relay are bimetallic trip units, transmission mechanisms and auxiliary switches. In Figure 1, the principle of operation of such a known relay is shown. The bimetal releases 100 through which the motor current I flows, a bimetal release for each phase and which are surrounded by the heating wire 101, act on a bridge system 200 with a release bridge 201 and differential bridge 202. If a bimetal release does not deflect or run back as much as the other two in the event of a phase failure, then put trigger bridge and differential bridge different ways back. The differential path of the bridge system is translated by the actuating lever 16 and transmitted to the rocker switch 400 via the transmission mechanism with a release lever 17 and a temperature compensation strip 300 which can be set as a function of the current. The rocker switch moves the auxiliary switch 500, which is designed as a snap switch with the normally closed contacts 95, 96 and galvanically separated normally open contacts 97, 98, and switches it when the motor is overloaded and switches off the motor contactor and thus the motor at risk. When the motor is switched off, the energy supply for the bimetallic releases 100 which are electrically connected in series with it is interrupted, these cool down again and return to the starting position. The relay has a current setting device 620 with which it can be set to different nominal motor currents. The relay can be switched on again either automatically A or by hand H, this mode of operation can be set by means of the restart lock 600, which also forms the unlock key and is referred to as the reset key. An off-test button 650 is also provided. Depressing button 650 opens the break contact and the circuit of the motor contactor is interrupted without a fault message being issued via the make contact of the auxiliary switch. Pulling the same button simulates a trigger, the test. The normally closed contact is opened and the normally open contact is closed in the test function. When operating with a restart lock, the changeover is retained until it is unlocked using the unlock button.

Thermal relays that work according to the above-described mode of operation have become known, for example, from DE-PS 22 62 387 or DE-OS 33 05 646.

A thermal relay is known from EP-PS 011 0758, which is composed of two housing parts in order to enable a space-saving design. In this case, the ones used for current monitoring are in a first housing part Bimetallic strips housed and in a second housing part of the safety switch, a transmission device and a thermal compensation device. To enable the housing to be installed, the housing parts and partitions are equipped with openings and window recesses. The relay is compact in design, but complicated to assemble, since the parts have to be assembled from different assembly directions and the two housing parts still have to be adjusted to each other.

The invention has for its object to construct the known thermal relays in terms of handling and ease of use on the one hand, the precision of the response in the event of overcurrent and phase failure as well as the economical production, i.e. easy to assemble, to improve. It is particularly important to facilitate the assembly of the auxiliary switch part with operating elements, with many individual elements that are subject to high dimensional accuracy having to be put together.

According to the invention, the object is achieved in a generic thermal relay with control elements arranged in the housing and accessible from the outside and an auxiliary switch influenced by this, in that all control elements are held on a support plate, that the support plate together with the control elements in that with the auxiliary switch parts, the transmission device and the bimetallic triggers can be inserted from the lockable side by means of the removable cover. The inserted support plate then forms part of the housing wall. The assembled carrier plate is only inserted into the housing after all other auxiliary switch parts have been installed. The carrier plate is first equipped with the correspondingly designed controls, whereby the assembly can be done automatically due to the clever construction. The carrier plate with control elements thus produced as a pre-assembled unit is then assembled with the housing for final assembly, none additional adjustment is required. The housing is also designed so that all parts to be inserted into the housing can be used from just one direction of assembly. The thermal relay is thus designed to be easy to install. The housing has removable parts on two sides, namely the cover and the carrier plate. This means that there are large openings for inserting the device parts. The device parts can all be inserted into the housing from just one direction of assembly. There is only one common housing for all parts to be used, so that additional adjustment work is not necessary. The housing itself can be manufactured with high precision. Since all device parts can be inserted into the housing from just one direction of assembly, automatic production is possible, for example using robots, which enables high precision and safety in the production of the thermal relays.

The relay according to the invention is also characterized in that all controls are arranged next to one another in an easily accessible place, both the setting element for the operating current, the test element for function testing of the switching function of the auxiliary switch and the operating element, which both the operating position for the Manual or automatic resetting of the auxiliary switch enables as well as the resetting of the auxiliary switch - Reset - includes. An advantageous structural design of the support plate for receiving and holding the operating elements can be found in the characterizing features of claim 2.

In a further embodiment of the invention, the carrier plate is additionally equipped with receptacles and holders for the elements to be actuated by the operating elements. An inventive guide and holder on the carrier plate which allows the adjustability of the test member can be gathered from the characterizing features of claim 3.

The operating device for the hand - automatic adjustment - for resetting the normally open contact is according to the characterizing features of claim 4 as a rotary knob with two snap-in positions and further perpendicularly movable for the reset required in manual operation as a reset button. The make contact, ie the adjustable fixed contact of the auxiliary switch, is adjusted via the bellcrank actuated by the operating element, which is also rotatably mounted on the underside of the carrier plate. In order to ensure the return of the bell crank, it is also equipped with a return spring which is also articulated on the carrier plate.

An expedient embodiment of the housing for the thermal relay, in order to be able to insert the support plate equipped with the operating elements during assembly as a finished module, provides for the housing to be designed, for example, like the features of claim 5. This design of the housing allows, despite the small size of the device, to create sufficient space overall for access to assembly and joining tools, with which the auxiliary switch parts, the transmission device and the bimetallic release can be mounted in the housing and then the carrier plate with the Controls can be used.

A further simplification of the assembly of the thermal relay is achieved according to the invention in that the cover is designed in accordance with the features of claim 6 with tubular connecting sockets, in particular molded connecting sockets for the plug connections, and all plug connections are held in a single holding frame. In this way, it is possible to assemble the plug connections preassembled in the holding frame into the housing at the same time in a single operation.

Since the bimetallic triggers not only respond to the temperature generated by the current, but are also influenced by the ambient temperature, they become caused fluctuations in the tripping current in the relay compensated by temperature compensation in the form of a bimetallic rod. This compensation bimetallic rod is provided in the transmission mechanism between the bimetallic release and the auxiliary switch, ie the rocker switch. Since the bimetallic triggers also respond to the current, it is necessary to be able to set the relay, the bimetallic triggers and also the compensation bimetallic rod to different nominal currents, for which purpose the current setting element is provided in the carrier plate. The setting to different current strengths is ultimately achieved by adjusting the triggering path of the transmission device.

Appropriate temperature compensation is also required for equipping the carrier plate with the current setting element according to the invention, i.e. a suitable design of the compensation bimetallic rod is required. According to a further proposal of the invention, an embodiment of the compensation bimetallic rod is proposed for this purpose, which at the same time for controlling the current, i.e. to adjust the current and to compensate for the ambient temperature. The combined control and compensation unit is characterized according to the invention by the characterizing features of claim 7. The compensation bimetallic rod is mounted and arched in a double suspension, which reduces the bending back and the compensation path is evened out. The contact point on the eccentric enables adjustment to different currents by adjusting the eccentric, i.e. of the adjusting element. The transmission path is influenced in a further embodiment in accordance with the features of claim 8. The fixed pivot point of the other end of the compensation bimetal rod thus defines the pivot point for the trigger lever for transmitting the bimetal triggering to the auxiliary switch via the connection to the shaft axis of the trigger lever.

By the construction of the Compensation bimetallic rod forms with the shaft axis of the release lever via the support part a triangle movable around the pivot point formed by the fixed end of the compensation bimetallic rod, the second corner point of which can be moved by the variable side length corresponding to the lengthening or shortening of the compensation bimetallic rod on the eccentric and its third the corner point formed at the center of the shaft axis of the release lever is forcibly adjustable by changing the position of the compensation bimetallic rod by a distance K which corresponds to the compensation. Due to the defined, preformed shape of the bimetallic rod, which is frequently curved, the transfer of the change in curvature via the tangent to the curvature, ie the supporting part, is possible, a large translation being achieved, so that high accuracy is possible through the compensation.

In order to be able to carry out the switching movement of the auxiliary switch as smoothly as possible and at the same time to stabilize the rocker switch against lifting off the fixed contact due to vibrations of the relay, in a further embodiment of the relay according to the invention it is provided that the rocker switch has a defined mass distribution at the center of gravity of the rocker switch in the bearing axis of the rocker switch or as close as possible to it. The center of gravity should be arranged as precisely as possible in the plane of the rocker switch bearing. In this way it is achieved that in the event of vibrations, in particular in the direction of the bearing, the opening moment is equal to the closing moment. This increases the shock resistance of the auxiliary switch break contact without affecting the switching movement. In a further embodiment of the invention, the rocker switch can be designed with two blades arranged in an alignment and forming the bearing axis for storage in bearing notches of the connection contact pieces of the auxiliary switch.

In order to allow a sufficient size of the rocker switch and sufficient switching paths, the rocker switch is preferred as open multi-chambered hollow body, so that the necessary size can be realized while saving weight. The shape and shape of the rocker switch is adapted to the switching movement, preferably in the two central planes perpendicular to the bearing axis, each mirror-symmetrically offset by 180 °. In order to achieve a defined mass distribution according to the invention, the switching rocker can be equipped with compensating masses in the form of webs and walls, possibly with the inclusion of materials of higher density, which protrude downward beyond the bearing axis.

The switching movement of the rocker switch is triggered by the transmission of the release path as a result of the bimetallic deflection via a transmission mechanism with levers, a tension spring being provided as the end member, which connects the rocker switch to the transmission mechanism. For the introduction of force of the kinetic energy it is now provided in a further embodiment that the rocker switch in the vertical central axis in the area above the bearing axis has an at least downwardly open cavity with a web for hooking the tension spring.

The invention is shown in the drawing using an exemplary embodiment of a thermal relay with structural details of the configuration.

Figur 1

das Funktionsprinzip eines thermischen Relais für Motorschutz

Figur 2

ein thermisches Relais für Motorschutz in Aufsicht

Figur 3

das Relais nach Figur 2 in Vorderansicht

Figur 4

einen Querschnitt durch das Relais gemäß Figur 2 durch die Steckanschlüsse

Figur 5

einen Querschnitt durch das Relais gemäß Figur 2 mit ansicht der Übertragungseinrichtung

Figur 6

einen Querschnitt durch das Relais gemäß Figur 2 durch den Hilfsschalterteil und Bimetallauslöser

Figur 7a-f

verschiedene Ansichten und Querschnitte der Trägerplatte

Figur 8a-d

verschiedene Ansichten der Trägerplatte gemäß Figur 7 bestückt mit Test- und Betriebsorgan

Figur 9a,b

zwei Ansichten des Testorganes gemäß Figur 8

Figur 10

Rückstellfeder

Figur 11a-c

Ansichten des Betriebsorganes gemäß Figur 8

Figur 12

Aufsicht auf komplett bestückte Trägerplatte gemäß Figur 8

Figur 13

Teilausschnitt für Funktion des Testorganes gemäß Figur 8

Figur 14

Teilausschnitt für Funktion des Betriebsorganes gemäß Figur 8

Figur 15a-c

Ansichten des Steckanschlusses

Figur 16a-c

Ansichten des Halterahmens

Figur 17a,b

zwei Ansichten der komplett ausgerüsteten Schaltwippe

Figur 18a-e

Querschnitt AA und verschiedene Ansichten der Schaltwippe gemäß Figur 17 ohne Kontaktwinkel

Figur 19a,b,c

drei Ansichten des Kontaktwinkels für die Schaltwippe gemäß Figur 17

Figur 20-23

die Kontaktanschlüsse des Hilfsschalters in je zwei Ansichten

Figur 24a,b

die Steuereinheit mit Temperaturkompensation in Seitenansicht und in Funktion

Figur 25

eine schematische Darstellung der Doppelaufhängung des Kompensations-Bimetallstabes.

Show it

Figure 1

the principle of operation of a thermal relay for motor protection

Figure 2

a thermal relay for motor protection under supervision

Figure 3

the relay of Figure 2 in front view

Figure 4

a cross section through the relay of Figure 2 through the plug connections

Figure 5

a cross section through the relay of Figure 2 with a view of the transmission device

Figure 6

a cross section through the relay of Figure 2 through the auxiliary switch part and bimetallic release

Figure 7a-f

different views and cross sections of the carrier plate

Figure 8a-d

different views of the carrier plate according to Figure 7 equipped with test and operating organ

Figure 9a, b

two views of the test organ according to FIG. 8

Figure 10

Return spring

Figure 11a-c

Views of the operating element according to FIG. 8

Figure 12

Top view of the fully equipped carrier plate according to FIG. 8

Figure 13

Partial section for the function of the test organ according to FIG. 8

Figure 14

Partial section for the function of the operating element according to FIG. 8

Figure 15a-c

Views of the connector

Figure 16a-c

Views of the holding frame

Figure 17a, b

two views of the fully equipped rocker switch

Figure 18a-e

Cross section AA and different views of the rocker switch according to Figure 17 without contact angle

Figure 19a, b, c

three views of the contact angle for the rocker switch according to FIG. 17

Figure 20-23

the contact connections of the auxiliary switch in two views

Figure 24a, b

the control unit with temperature compensation in side view and in function

Figure 25

is a schematic representation of the double suspension of the compensation bimetal rod.

The motor protection relay 1 shown in FIGS. 2 to 6 works according to the physical principle as a bimetal relay, as was explained with the functional principle of FIG. 1. In the housing 10, which is covered on one side of the housing with the cover 13 and on the upper side in the partial area of the auxiliary switch parts by means of the carrier plate 60, the bimetallic triggers 100, see FIG. 6, are accommodated with the bridge system 200, which consists of a tripping bridge with a differential bridge. The heating coil 101 surrounds the individual bimetal releases and can be connected at one end to a power supply device via plug connections 66. The plug connections are inserted and held in tubular sockets 132 formed on the outside of the cover 13. For simplified assembly, the plug connections 66 are inserted into the holding frame 67 and are inserted as a module in the housing, the cover 13 is plugged onto the plug connections 66 from the front with the sockets 132. The three phases of the motor current are connected to the bimetallic release 100 via the connections 2, 4, 6 and contact tabs 20. In the event of an overload, the bridge system 200 in is bent by bending the bimetal release 100 The direction of the arrow G moves and triggers the switching movement of the rocker switch 400 in the direction of the arrow F via the transmission device with the actuating lever 16, bimetal compensation rod 300, release lever 17, tension spring 125. The movement is triggered by the tension spring 125, which is attached at one end to the rocker switch 400 and at the other end to a screw 126 arranged on the housing 10 and is actuated by the release lever 17. If the tripping path that can be set as a function of the current intensity by means of the bimetal compensation rod 300 is exceeded, the break contact 95, 96 of the auxiliary switch is opened by switching the rocker switch and the downstream motor contactor (not shown here) switches off the endangered motor. At the same time, the normally open contact 97.98 is closed by switching the rocker switch. The relay according to FIGS. 2 to 6 is equipped with an adjusting element 620 in the form of a rotatable eccentric for setting the size of the nominal current. Furthermore, an operating device 600 with unlocking, also referred to as a reset button, is provided with the operating position “auto” or “manual”. Be the setting "auto", which works without restart lock, the rocker switch automatically returns to the starting position and closes the break contact, so that the motor switches on again automatically after tripping. In the "manual" position, a restart lock is used and the rocker switch must be reset to the starting position by manually pressing the reset button. The relay also has a test lever 650, which is designed as a multi-function key, in order to simulate by hand a trial opening of the normally closed normally closed contact and closing of the normally open contact for testing or commissioning. These three controls for current setting 620, operation 600 and testing 650 are attached to the carrier plate 60 and are mounted together with this in the housing 10. The housing 10 is divided by the wall 103 into two chambers, the bimetallic release and the bridge system 200 being accommodated in one chamber and the auxiliary switch parts and carrier plate with operating elements in the other chamber. Partition walls 104 are also provided between the individual bimetal releases 100. The carrier plate is inserted and guided in grooves 102 of the housing. The front of the two chambers is closed by the cover 13. The test element 650 is guided with its lever 652 in the chamber of the auxiliary switch parts in such a way that, when actuated appropriately, it can open the break contacts 95/96 and close the contacts 97/98 by switching the rocker switch 400.

In FIGS. 7a to f, the carrier plate, which is fitted with the operating elements as a preassembled unit, is completely inserted into the housing 10 during final assembly, in an advantageous embodiment. The carrier plate with an approximately rectangular shape, which closes the housing chamber 105 receiving the auxiliary switch on the upper side, has guide strips 602 along the sides that come into contact with the housing walls, which engage in corresponding grooves in the housing. The bulge 603, preferably stepped, is formed on the end face 618 of the carrier plate 60, which is later closed with the housing cover 13. The setting element for the current, for example in the form of the eccentric 620, can be inserted into this bulge 603 from the side. The recess 604 for receiving the test element 650 is formed approximately in the center along the side of the carrier plate which bears against an outer wall of the housing 10. This test organ is also inserted into the carrier plate from the side. To accommodate the operating member 600, the support plate is formed with the through bore 605, which is formed on the underside of the support plate with pairs of webs 6051, 6052, of which the webs 6051 are provided with locking hooks projecting from the bore. Figure 7d shows the side view of the carrier plate on the cut-out opening 604, FIG. 7e the longitudinal section A5B5, FIG. 7b the cross section D1D1 and FIG. 7c the cross section C1C1 and FIG. 7f the bottom view of the carrier plate 60. From FIG. 7c it can be seen that the receiving bore 605 for the operating element two paragraphs is formed in different levels for corresponding locking positions of the operating element 600. In addition, a receiving pocket 608 is formed on the carrier plate on the underside of the carrier plate on the side opposite the cutout opening 604 by means of a projecting web 609. A bearing in the form of bearing blocks 606 is formed on the underside of the carrier plate along one side opposite the bore 605 for the storage and fastening of the bellcrank for the reclosing lock or the self-decay of the rocker switch. The guide strips 602 can have a dovetail shape, for example. The support plate 60 is to be mounted in a precise position, therefore the catch cam 607, which engages in a corresponding groove in the housing wall, is formed on the underside of the support plate opposite the insertion side.

FIGS. 8a to 8d show the carrier plate 60 equipped with the test element 650 and the operating element 600. The test element 650, which is formed in two further views in FIGS. 9a and 9b as a lever 652 which has been bent several times, can be adjusted in the direction of the arrow to carry out the test function. As the detail according to FIG. 13 also shows, the test element 650 is guided on the underside of the carrier plate 60 in the pocket 608 by a guide web 651 which extends at right angles to the longitudinal extent of the lever 652. The guide web 651 is designed to be somewhat elastic, so that guidance is ensured when the test element 650 moves up and down in the direction of the arrow. The test lever 652 of the test element also has a longitudinally projecting guide rib 653.

The operating element 600 is a multi-function key. By rotation, two snap positions are in different levels possible that cause either the self-decline of the rocker switch or the self-locking of the rocker switch by a corresponding adjustment of the adjustable fixed contact 98 forming the normally open contact. In addition, the self-locking can be released again by actuating the operating element 600. FIGS. 8 in conjunction with FIGS. 12 and 14 show the design of the operating element 600 and mode of operation using an exemplary embodiment. The operating element 600 is designed, for example, in the manner of a cap nut, see FIGS. 11a to 11c, with the through bore 613 for receiving a threaded pin 610. In the bore 613 guide ribs 614 are provided, on the outside the projections 611 and 612 are formed at different locations, making it possible to snap them into the operating position "auto" or "hand" by turning the operating element 600 accordingly. On the head side there are slots 605 or 616 throughout. As can be seen from FIGS. 12 and 14, the operating element 600 cooperates with the deflection lever 670, which is in contact with the stop end 6701 with the adjustable fixed contact 98. The bell crank 670 is of an angular design and is rotatably fastened at the other end 6702 in the bearing blocks 606 on the underside of the carrier plate 60. In order to ensure the correct return of the bell crank 670 in the “auto” and “hand” modes, the return spring 660, for example a leaf spring, as shown in two views in FIG. 10, is articulated on the bell crank in a pocket 6704 and also on the other Fixed end in the area of the pedestals 606. The position of the bell crank 670 shown in dashed lines in FIG. 14 corresponds to the automatic operating position of the relay, ie that the rocker switch automatically returns to the starting position after the switchover. In the manual position of the deflection lever 670, which is shown as a solid line in FIG. 14, the unlocking is carried out by pressing the operating element 600 in the direction of the arrow, which is used as a reset button.

In order to achieve simultaneous assembly of the plug connections, these are, for example, as in FIGS. 15a to c shown, formed with contact lug 661, plug 663 and U-shaped loop 662. A single holding frame 67, as shown in FIGS. 16a to 16c, has U-shaped cups 671, 672, 673, which are connected to one another by a web 674. The connectors 66 with the loop can be inserted into the wells and then attached to the housing as a pre-assembled unit.

An advantageous shape of a rocker switch with a defined center of gravity in the tilting and bearing plane L is shown in FIGS. 17 to 18. The rocker switch of FIGS. 17a, b is complete, ie equipped with contact angles 41, while the cross sections, bottom view, top view and the two partial perspectives according to FIGS. 18a-e show the rocker switch 400 without a contact angle. The cutting edge bearing 401 is brought about by the cutting edges 43 formed on the contact angles 41 below, which form the bearing plane and the axis of rotation L. The rocker switch is mirror-symmetrically offset by 180 ° around each of the vertical central axes M and D, so that two identical contact angles 41 can be arranged on both sides 409 and 410 of the rocker switch. The introduction of force for the switchover movement of the rocker switch 400 should take place symmetrically in the central axis, for which purpose the web 402 is provided in a cavity 406 of the rocker switch that is at least accessible from below for hanging the force-transmitting tension spring. The web 402 is located approximately at the level where the contact surfaces or contact pieces 42 of the contact angle 41 also extend on the outside. The rocker switch now has a defined mass distribution with a corresponding configuration such that the center of gravity of the rocker switch 400 comes to lie in the bearing axis L as far as possible. For this purpose, the rocker switch is equipped with lateral projections 404 and 405 extending downward beyond the bearing axis L on both sides of the central axis M in the form of walls or webs or the like. In order to make the area of the rocker switch, which is located above the bearing and rotation axis L, as light as possible, this area is preferably equipped with cavities. To at compact design to achieve a defined shift of the center of gravity in the axis of rotation L can also be attached to the lateral downward projecting parts 404 and 405, for example, heavy mass particles, while the rocker switch itself is made, for example, of a relatively light plastic.

FIGS. 19a, b, c show an advantageous embodiment of the contact angle 41 for the rocker switch with molded cutting edge 43 in the three views from the front, from the side and from above. The contact angle 41 has an approximately angled L-shaped shape, the contact piece 42 being provided on the protruding angle arm 41a. The cutting edge 43 is formed on the foot of the other angle arm 41b. According to the configuration of the rocker switch, the angle arm 41a of the contact angle is bent in the second plane, see FIG. 14c, which creates the contact surface B on the rocker switch. Other forms of the contact angle 41 are also conceivable. For the cutting edge formation 43, for example, an angle of 30 ° is expedient. The mutually mirror-inverted contact angles 41 assigned to the rocker switch then form with their cutting edges 43 an aligned line which forms the bearing and axis of rotation L and in which the center of gravity of the rocker switch should also be as precise as possible. The contact angles 41 are guided, for example, in insertion grooves 403 of the rocker switch 400 with a precise fit, at the lower end of which the blades 43 formed on the contact angles 41 protrude for storage.

The counter bearing of the rocker switch is formed by the contacts 95 and 97 of the rocker switch of the auxiliary switch, which are housed in the housing 10 of the relay. The connections 95 and 97, see FIGS. 22 and 23 each consist of a connection angle, shaped more or less in accordance with the available space, more or less in a Z shape, which is fastened on one side in the respective connection screw 951 and 971, respectively. A V-shaped notch 952 and 972 is located at the free, upstanding, other end of the connection bracket formed, which form the cutting edge bearing for the cutting edges 43 of the rocker switch. The connections 96 and 98 of the fixed contacts of the auxiliary switch assigned on the opposite side of the rocker switch each have the connection screw 961 and 981 with the correspondingly shaped connection angles 96 and 98, which are more or less resilient, see FIGS. 20 and 21.

The rocker switch 400 of the thermal relay of the example shown is also designed for electrical isolation between the normally closed and normally open contacts.

The triggering path is adjusted according to different current strengths to be monitored via the setting element 620, e.g. a rotary knob with scales, which adjusts the adjacent bimetal compensation rod 300 via an eccentric. 26a, b show the structure of a control and compensation unit according to the invention with the compensation bimetal rod 300 in a schematic view. The compensation bimetal rod 300 is permanently pre-formed mechanically with a uniform circular arc shape with a curvature corresponding to the radius r. In the area of one end, the compensation bimetal rod 300 is mounted at a fixed pivot point M3. The fixed pivot point is formed, for example, by the axle or bolt 302, which is rotatable in a bearing bush 304 attached to the housing 10. The compensation bimetal rod 300 is fixedly connected to the axle bolt 302 in the region 301, for example welded, and can be rotated about the fixed pivot point M3 in the bearing bush 304. The attachment point 301 is preferably arranged on the convex side 308 of the compensation bimetal rod.

At the other end 305, the compensation bimetal rod 300 is supported with its convex side 308 on the eccentric of the setting member 620 for the nominal current. The contact surface 621 on the eccentric 620 practically forms a rotary contact surface for the compensation bimetallic rod, which at the same time increases or decreases pushes along this pivot point, whereby the contact point M2 of the compensation bimetallic rod is moved to M2 '.

The release lever 17 is rotatably mounted about the shaft axis 170 and transmits the release movement by a stop at its end 171 to the other end 172. The release paths, see arrows H1, H2, are calibrated by means of the temperature compensation with the aid of the compensation bimetal rod 300. The shaft axis 170, which carries the release lever 17, is rigidly connected to the compensation bimetal rod 300 via the support part 310, for example a metal rod, for example by welding the shaft axis 170 in the area 307 to the support part 310 and in the area 306 by welding the support part 310 with the compensation bimetal rod 300. Here it is essential that the supporting part 310 is articulated and welded tangentially to the convex side 308 of the compensation bimetal rod, and also tangential to the shaft axis 170 of the release lever. The center point M1 of the shaft axis 170 can be moved in the direction of the arrow K when the position of the support part 310 changes, and thus the stop surfaces are also shifted or the release paths of the lever ends 171 and 172 change, for example oriented at the center point M0 of the lever end 171 of the release lever 17 .

As shown in FIG. 25, one end of the compensation bimetal rod 300 can be rotated about the fixed pivot point M3, while the shaft axis 170 with the center point M1, which are articulated via the support part 310, are freely movable in the direction of arrow K. The other end 305 of the compensation bimetal rod is slidably guided at the end M2. This displaceability at point M2 enables control on the one hand according to the adjustable nominal current in which the contact point M2 is displaced by changing the position of the eccentric 620. Another possibility of displacement in the direction of arrow K1 results from the fact that, by changing the ambient temperature when the eccentric 620 is permanently set, the compensation bimetal rod is Length changed and thus shifts its contact point to M2 '. The arrangement of the uniformly curved compensation bimetal rod according to FIG. 26a thus fulfills both the task as a control unit and as a compensation unit.
The compensation bimetallic rod 300 is mounted in a double suspension, whereby the release lever can be moved from M1 to M1 'by the path K around the fixed pivot point M3, corresponding to the displacement of the other end of the compensation bimetallic rod 300 from M2 to M2' by the path K1. This shift can either be controlled or triggered by changing the ambient temperature.

FIG. 24 schematically shows compensation compensation when the ambient temperature rises for the compensation bimetal rod 300 according to FIG. 24a. As a result of the extension of the bimetallic rod 300 along the contact surface 621 on the eccentric 620 in its longitudinal extension in the direction of the arrow K1, the support part 310 is carried along and changes the position of the release lever 17 at its other end via the shaft axis 170 attached thereto. This also makes the position M0 of the stop lever end 171 moved to M0 ', which corrects the release path, ie is compensated for according to the ambient temperature. This also applies to the other lever end 172 of the release lever 17.

The first link of the transmission device for triggering the auxiliary switch as a result of the bimetallic deflection forms a calibrated bridge system 200 with a differential bridge and release bridge made of two comb-like bridge parts and a hinged actuating lever 16 for the thermal relay according to FIGS. 2 to 6.

As can be seen, for example, from FIGS. 5 and 6, the movement triggered by the bimetallic elements is transmitted via the bridge system 200 to the actuating lever 16, which sets the trigger lever 17 in motion, so that it moves about its axis of rotation with the other end of the tension spring 125 and thus triggers the rocker switch.

Claims (12)

1. Thermal relay with bimetal trips (100) accommodated in a housing having at least one side which can be closed by means of a cover, and with an auxiliary switch (500) with operating rocker (400) and a multi-part transmission device having a compensating bimetal rod (300) for the ambient temperature, said multi-part transmission device responding to the bending of the bimetal element and actuating the auxiliary switch, and with control elements in the form of a preset control (620) for the current by varying the tripping path of the bimetal trip, a test device (650) for testing the switching function of the auxiliary switch and an operating device (600) for resetting the auxiliary switch to the original position either manually or automatically, characterised in that the control elements (600, 620, 650) are retained at a support plate (60), that the support plate together with the control elements can be inserted into the housing, fitted with the auxiliary switch parts, the transmission device and the bimetal trips, by means of the side which can be closed by means of the removable cover (13).
2. Relay according to Claim 1, characterised in that the support plate has a curved recess (603) at the end face (618) facing the cover (13) of the housing (10), in which curved recess the preset control (620) for the current, and constructed as a cam, can be inserted from the side, and at a side of the support plate adjacent to the end face that is arranged along an outer wall of the housing (10) there is formed an opening (604) into which the test device (650) can be inserted from the side, and a continuous drilled hole (605) into which the operating device (600) is inserted, is provided in the support plate, whereby a pair of webs (6051) is formed having locking hooks opposite to each other, said pair of webs protruding as an extension of the drilled hole on the underside of the support plate.
3. Relay according to Claim 1 or 2, characterised in that the test device (650), which can be adjusted perpendicularly to the support plate (60), has a guide web (651) extending at right-angles to said test device on the underside of the support plate, the end of said guide web being guided in a pocket (608) that is formed on the side of the suppcrt plate opposite to the opening (604) and at a slight distance from the underside of said support plate.
4. Relay according to one of the Claims 1 to 3,
   characterised in that the operating device (600) is constructed as a rotary knob which can be moved along the drilled hole (605) of the support plate in the form of a bayonet fastener into two locking positions in different planes of the support plate, and the operating device is in contact with a swivel-mounted shift lever (670) on the underside of the support plate (60), said shift lever varying its position and the position of the adjustable fixed contact (98) of the auxiliary switch according to the position of the rotary knob (601), which adjustable fixed contact is in mechanical contact with said shift lever.
5. Relay according to one of the Claims 1 to 4,
   characterised in that a partition (103) arranged between the parts of the auxiliary switch and the bimetal trips subdivides the housing (10) into compartments which are open along one side of the housing, and of these compartments the one that contains the parts of the auxiliary switch is open at the top, and the top side can be closed by inserting the support plate (60) fitted with the control elements (600, 620, 650) from the open side of the housing, and the open side of the housing can be closed by plugging in the cover (13) which extends over the two compartments.
6. Relay according to one of the Claims 1 to 5,
   characterised in that in the region of the compartments receiving the bimetal trips (100), the cover (13) is constructed with tubular connecting sockets (132) for plug connections (66), with the plug connections (66) being retained by a U-shaped loop (662) in cup-like receptacles (671, 672, 673) of a retaining frame (67) resting on the inner side of the cover (13).
7. Relay according to one of the Claims 1 to 6,
   characterised in that for control of the current and for compensation of the ambient temperature, the compensating bimetal rod (300) is mechanically preformed in the shape of a uniform arc and is supported at one end (301) on a fixed-position rotary bearing (304) arranged in the housing (10) and is supported at the other end at its convex side (308) at the cam of the preset control (620).
8. Relay according to Claim 7, characterised in that the compensating bimetal rod (300) is permanently attached to a shaft axis (170), about which a tripping lever (17) can rotate, by means of a supporting component (310) lying tangentially on the convex side (308) of the compensating bimetal rod (300) and on the shaft axis (170), the tripping lever forming one element of the transmission device.
9. Relay according to one of the Claims 1 to 8,
   characterised in that the operating rocker (400) forming the moving contact of the auxiliary switch has a defined mass distribution by which the centre of gravity of the operating rocker is located at, or as closely as possible to, the support axis of the operating rocker.
10. Relay according to Claim 9, characterised in that the operating rocker (400) is constructed with two knife-edges arranged in alignment and forming the support axis (L) for a bearing in bearing notches of the contact pieces (95, 97) of the auxiliary contact.
11. Relay according to one of the Claims 9 or 10,
    characterised in that the operating rocker (400) has balancing weights in the form of webs and partitions (404, 405), possibly incorporating high-density materials, that project downwards beyond the support axis (L).
12. Relay according to one of the Claims 9 to 11,
    characterised in that the shape of the operating rocker (400) is offset by 180° in mirror-image fashion in each case in both central planes (D, M) perpendicular to the support axis (L) and is constructed as an open, multi-compartment hollow body that has, in an open hollow space (406) opening downwards and arranged in the centre axis, a web (402) arranged above the support axis (L), which web serves to anchor a tension spring (125) and to introduce the force of the kinetic energy for the operating rocker.

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