EP0673047B1 - Switch - Google Patents

Abstract

The switch has a manual operating button (2), displaced against a return spring bias, with a ratchet mechanism for holding the switch in the on position. The ratchet mechanism can be released manually, or electrically or electronically, with the operating button returned to the off position via the return spring bias. The ratchet uses a ratchet cam attached to the operating button and a cooperating ratchet element, which is released by moving it out of engagement with the cam, e.g. via a release electromagnet (7).

Description

The invention relates to a switch, in particular a power switch, for electrical or electronic devices, with an actuating button which can be actuated manually against the force of a spring, in particular a compression spring, and which, in order to create a latching mechanism for the on-position of the actuating button, has a positive guidance for an engagement therein and counter element (22) which engages in the on position, the counter element being able to be brought out of engagement with the positive guidance of the actuating button to unlock it by moving the counter element out of the positive guidance by means of the control of an electromagnet, such that the actuating button can be moved again due to the force of the spring automatically moved from the on position to the off position.

The known device power switches are mostly pressure switches. They have an idle position, namely an off position, in which the operating button of the switch rests in a "forward" position and the 2-pole circuit for the mains voltage is thereby interrupted. As a second state, these pressure switches have an on position, which is achieved by pushing the actuating button in, with a snap-in mechanism using a so-called switching heart. As a result, the switch with the actuating button remains in this "rear" locking position. In this position the 2-pole circuit is closed. To return to the off position, the operating button must be pressed in again. This unlocks the locking position and the actuating button is pushed back into the off position by a previously tensioned compression spring. This will interrupt the circuit again. The disadvantage of these known device power switches in the form of pressure switches is that they can only be operated manually.

DE-B-1 415 591 discloses a pushbutton arrangement with an electromagnetic unlocking of the mechanical locking in the working position of the type specified at the outset. For this purpose, a manually operable switch is provided, which has a locking lever that can be pivoted about a screw and has a curve that defines a positive guidance. In operative connection with this locking lever is a locking pin of a magnetic core, which is axially movable in an outer magnet coil 16. The axially movable magnetic core is acted upon by a compression spring and is pressed into the positive guidance of the curve of the locking lever. When the actuator is depressed, the locking lever moves after a brief evasive movement the locking pin in the curve of the locking lever and engages there so to speak, so that the actuator is held in its lower position. In order to be able to electrically unlock the actuator, the magnet coil is excited and the axially movable magnetic core with its locking pin is displaced such that the locking pin disengages from the curve (positive guidance) of the locking lever, so that the actuator returns to its initial position due to a compression spring , ie, the off position flips back. - The disadvantage of this known switch is that the electrical unlocking device with the electromagnet must be relatively complex and therefore expensive to be able to provide the necessary forces for unlocking.

Proceeding from this, the object of the invention is to provide an improved switch, in particular a mains switch, for electrical or electronic devices, in which the electrical locking and / or unlocking is possible by means of a relatively weak electromagnet.

As a technical solution , the invention proposes that the positive guidance is formed in a switching heart of the actuating button and that a two-armed, pivotable lever is provided, the counter element being arranged on the first lever arm and a pivoting device being associated with the second lever arm and the second lever arm has a metal body to which the electromagnet is assigned.

This creates a switch, in particular a power switch, for electrical or electronic devices with a technically simple and inexpensive controllable unlocking. The basic idea of the electronically controlled, automatic unlocking according to the invention is that the counter element, which engages in the positive guidance of the switching heart of the actuating button, can be moved by means of the electronic component by means of a current or voltage pulse such that it disengages from the positive guidance of the switching heart Unlocking the actuating button can be brought. As a result, the forced operation and forced positioning of the actuating button in its on position is canceled, so that the actuating button automatically returns to the unlocked off position due to the spring action. The particular advantage of the switch according to the invention is that the electrical unlocking is subject to minimal wear and tear since the counter element is moved out of the positive guidance during the electrical unlocking. Another particular advantage of the locking and unlocking device according to the invention is that the appropriate design of the lever can create lever ratios which require a relatively weakly designed electrical component for the pivoting device of the lever.

The lever can be angled. One lever arm end carries the counter element, which can be designed as a pin. The pivoting device engages at the other end of the lever arm. This can be a combination of a mechanical and electrical, in particular electromagnetic, pivoting device.

The lever is preferably spring-loaded in the basic position. For this purpose, a spring can be supported between the housing of the switch and the lever, which can preferably be a compression spring or tension spring, in particular in the form of a helical spring. Of course, leaf springs etc. are also conceivable. Due to the spring loading of the lever, the lever automatically returns to the starting position when it is unlocked electrically.

A further development suggests that in the off position of the actuation button, the counter element is disengaged from the positive guidance of the switching heart and that when the actuation button is pressed from the off position to the on position by a guide surface between the actuation button and the lever Counter element can be brought into engagement with the positive guidance of the switching heart. This means that the counter element only comes into the positive direction of the switching heart when the actuating button is pressed. This creates a mechanical possibility to transfer the counter element from the disengaged position to the engaged position in the forced operation of the switching heart. For this purpose, the actuating button has a corresponding switching cam, which cooperates with an associated counter surface of the lever and thereby pivots the lever when the actuating button is pressed down.

A development of this proposes that a permanent magnet is provided which magnetically holds the lever in the engaged position of the counter element in the positive guidance of the switching heart after the lever has been pivoted by hand for a certain distance by means of the pivoting device, and that the electromagnet is used for a short time Excitation cancels the magnetic force of the permanent magnet so that the lever returns to its original position. The basic idea is that the lever is first pivoted a short distance by hand until the permanent magnet acts and attracts and holds the lever. For this purpose, the lever has a metal piece which interacts with the permanent magnet. The electrical release takes place in that the electromagnet is briefly energized, so that the magnetic force of the permanent magnet is canceled, so that the lever can pivot back into the disengaged position due to the spring force.

An alternative possibility provides that the electromagnet magnetically holds the lever in the positive position of the switching heart in the engaged position of the counter element during the duration of its excitation. This provides the opposite case to the previously mentioned case in that the excitation of the electromagnet secures the on position of the actuating button, while the electrical unlocking takes place when the electromagnet is switched off.

A preferred development proposes that the latching position can be unlocked manually by pressing the actuating button in the on position again. The basic idea of this further development is that, in addition to the electronic unlocking device according to the invention, a "conventional" manual on / off actuation with manual unlocking of the on / off position is also possible by pressing (and releasing) the actuating button again. To switch off the device, you have the option of doing this manually, on the one hand, or choosing electronic unlocking, on the other.

A further development suggests that the forced guidance of the switching heart is three-dimensional, with the forced guidance having a recess in the third position in the on position of the counter element. This depression keeps the counter element even more securely in the on position of the switching heart.

A further development of the switch according to the invention proposes that the actuating button is directly or indirectly in operative connection with a button for switching the circuit. Such a button is a current switching element with a switch without a locking mechanism. In this case, a special separate latching mechanism of the type according to the invention is built on the button, which offers the desired possibility of electronically controlled, automatic unlocking, but at the same time also the "conventional" manual on / off actuation with manual unlocking of the on latching position by pressing again (and release) the control button. When the button is pressed, it makes its working stroke and closes the circuit formed by its contacts.

In the direct operative connection between the actuation button and the button, the actuation button is in direct operative connection with a control cam of the button via a control cam. This is one possibility that when the actuating button is operated manually, it acts directly on the button, so that it makes its working stroke and closes the circuit.

In the indirect operative connection between the actuation button and the button, a compression spring is preferably arranged, the compression spring thereby tensioned triggering the switching function of the button when the actuation button is depressed. This also represents a technically simple possibility to convert the button into its switching function in a technically simple manner by actuating the actuation button. Of course, the compression spring must have such a spring characteristic that the force when pressing the actuating button is large enough to be able to actuate the button at all.

Either a 2-pin button is provided as the button or two 1-pin buttons are provided. In the case of the 2-pole push button, an indirect operative connection with the actuation button offers itself, while when using 1-pole push buttons, direct actuation by the actuation button is preferably provided.

Furthermore, it is proposed in a further development that the button is equipped with or without a snap characteristic. It is therefore fundamentally possible to use pushbuttons with or without a snap characteristic, those with a snap characteristic having the advantage that shorter opening and closing times of the contacts can be achieved, which benefits the electrical service life.

Finally, it is proposed in a further development that the actuating button has guide bevels by means of which contact springs fixed to the housing can be brought into contact with switching contacts which are also fixed to the housing. This is also a technically simple way to trigger a switching operation using the switch.

Fig.1

eine Längsschnittdarstellung des Schalters;

Fig.2

die Ein-Stellung des Schalters in Fig. 1.

An embodiment of a switch according to the invention in the form of a device power switch is described below with reference to the drawing. In this shows:

Fig. 1

a longitudinal sectional view of the switch;

Fig. 2

the on position of the switch in Fig. 1st

The switch has a housing 1, in which an actuation button 2 - in the drawing - is mounted so that it can move vertically. This actuating button 2 has a switching heart 3 with a positive guide at its lower end. Between the housing 1 and the actuation button 2, a compression spring 4 is supported, which tries to push the actuation button 2 into the upper off position. The lower end of the actuating button 2 is via switching cams 19 in contact with spring contacts 20, which when the Actuate button 2 corresponding circuits close, as in particular a comparison of FIGS. 1 and 2 shows.

An angled, two-armed lever 21 is mounted within the housing 1 so as to be pivotable about a pivot axis V. One lever arm 21 ′ of the lever 21 has a counter element 22 in the form of a pin at the front end, which is located in the region of the switching heart 3. The other lever arm 21 ″ carries a metal body 23, as well as a guide surface 24. A compression spring 25 is supported between the housing 1 and the lever 21. The actuating button 2 has a switching cam 27 on a cantilever 26 which is in contact with the guide surface 24 of the lever arm 21 "cooperates. Finally, an electromagnet 28 and, not visible, a permanent magnet are arranged in the housing 1.

The switch works as follows:

In Fig. 1 the basic position, i.e. Switch position shown, i.e. the actuating button 2 is in its upper position, in which it is held by the compression spring 4. By the compression spring 25, the lever 21 is pivoted such that the pin-like counter element 22 is out of engagement with the positive guidance of the switching heart 3.

When the operating button 2 is pressed down, its switching cam 27 comes into engagement with the guide surface 24 of the lever 21 and moves it down until the permanent magnet in interaction with the metal body 23 of the lever 21 develops such a force that the force of the compression spring 25 is overcome and thus pulls the lever 21 with its lever arm 21 "downward and holds the lever 21. In this position, the pin-like counter element 22 comes into engagement with the positive guidance of the switching heart 3, so that the actuating button 2 is held in this lower on position At the same time, the spring contacts 20 are brought into the closed position.

In addition to the manual unlocking of the operating button 2, in which it is pressed down again, an electrical unlocking is also possible in that the electromagnet 28 is briefly acted upon with a corresponding voltage, so that the electromagnet 28 generates a magnetic field which the magnetic field of the Permanent magnet cancels. As a result, the force of the compression spring 25 is greater and pivots the lever 21 counterclockwise, so that the counter element 22 disengages from the positive guidance of the switching heart 3. The compression spring 4 then moves the operating button 2 upwards into the off position. At the same time, the spring contacts 20 are opened.

An alternative is to omit the permanent magnet. In this case, when the actuating button 2 is pressed down by the spring contacts 20, i.a. the electromagnet 28 is energized so that it attracts the metal body 23 of the lever 21 and thus holds the lever 21 in the position shown in FIG. 2. This position of the lever 21 is maintained as long as the electromagnet 28 is excited and generates a corresponding magnetic field. For the electrical unlocking, the electromagnet 28 is simply switched off by interrupting the voltage supply. As a result, the compression spring 25 pushes the lever arm 21 "upward and pivots the lever 21 in such a way that the peg-like counter element comes out of engagement with the positive guidance of the switching heart.

The switch according to the invention has the advantage that both manual and electrical unlocking are optionally possible. With manual unlocking, the operating button 2 is operated a second time (and released). The electromagnet (28) is actuated during the electronically controllable unlocking. Only a few individual parts are required for the proposed switching system with automatic unlocking. This also results in little assembly effort, so that another advantage is that only low manufacturing costs are incurred.

Reference list

1

casing

2nd

Control button

3rd

Switching heart

4th

Compression spring

19th

Switch cams

20th

Spring contact

21

lever

21 ', 21 "

Lever arm

22

Counter element

23

Metal body

24th

Leadership area

25th

Compression spring

26

boom

27

Switch cams

28

Electromagnet

V

Swivel axis

Claims (13)

1. Switch, in particular a mains switch, for electrical or electronic devices, with an actuating knob (2) which can be controlled manually against the force of a spring, in particular a pressure spring (4), the said knob, to create a ratchet mechanism for the On position of the actuator knob (2), having a restraint for a counter-element (22) engaging in this and locking in the On position,
   where the counter-element (22) can be moved, by means of controlling an electromagnet (28), out of engagement with the restraint of the actuator knob (22) to unlock, by the counter-element (22) moving out of the restraint, such that the actuating knob (2) automatically moves from the On position back to the Off position under the force of the spring,
   characterised in that

   the restraint is formed in a switch core (3) of the actuator knob (2) and

   in that a two-armed swivellable lever (21) is provided, where the counter-element (22) is arranged on the first lever arm (21') and a swivel device is allied to the second lever arm (21"), and the second lever arm (21") has a metal body (23) which is allied to the electromagnet (28).
2. Switch according to claim 1,
   characterised in that
   the lever (21) is spring-loaded in the base position.
3. Switch according to claim 1 or 2,
   characterised in that
   in the Off position of the actuator knob (2), the counter-element (22) is out of engagement with the restraint of the switch core (3), and that on pressing the actuator knob (2) from the Off position to the On position the counter-element (22) can be brought into engagement with the restraint of the switch core (3) via a guide surface (24) between the actuator knob (2) and the lever (21).
4. Switch according to claim 3
   characterised in that
   a permanent magnet is provided which holds the lever (21) magnetically in the engagement position of the counter-element (22) in the restraint of the switch core (3) after the lever (21) has been manually swivelled for a certain distance by means of the swivelling device, and that the electromagnet (28), on short excitation of the magnetic force of the permanent magnet, is neutralised such that the lever (21) returns to its starting position.
5. Switch according any of claims 1 to 3,
   characterised in that
   during the period of its excitation, the electromagnet (28) holds the lever (21) magnetically in the engagement position of the counter-element (22) in the restraint of the switch core (3).
6. Switch according to any of the previous claims,
   characterised in that
   by repeated pressing of the actuator knob (2) in the On position, the rest position can be unlocked manually.
7. Switch according to any of the previous claims,
   characterised in that
   the restraint of the switch core (3) is constructed three-dimensionally, where in the third dimension the restraint has a recess in the On position of the counter-element (22).
8. Switch according to any of the previous claims,
   characterised in that
   the actuator knob (2) is actively connected directly or indirectly with a key switch (5) for switching the circuit.
9. Switch according to claim 8
   characterised in that
   in the case of indirect active connection between the actuator knob (2) and the key switch (5), the actuator knob (2) stands in direct active connection via a radial cam (11) with a peripheral cam (12) on the key switch (5).
10. Switch according to claim 8,
    characterised in that
    in the case of direct active connection between the actuator knob (2) and the key switch (5), a pressure spring (4) is arranged where on depression of the actuator knob (2) the pressure spring (4), tensioned as a result, trips the switch function of the key switch (5).
11. Switch according to any of claims 8 to 10,
    characterised in that
    one 2-pole key switch (5) or two 1-pole key switches (5) are provided.
12. Switch according to any of claims 8 to 11,
    characterised in that
    the key switch (5) is equipped with or without a snap action.
13. Switch according to any of claims 1 to 7,
    characterised in that
    the actuator knob (2) has guide obliques (18) by means of which contact springs (16) with robust housings can be brought into contact with switch contacts (17) with equally robust housings.

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