DE102007040047B3 - Electrical switch has housing, and plastic deformation element is provided on actuator for damping the excessive force effect in addition to elastic deformation element - Google Patents

Abstract

The electrical switch has a housing (1). A plastic deformation element (6) is provided on the actuator (3) for damping the excessive force effect in addition to the elastic deformation element (7). The deformation energy consumption of the deformation element is greater than the deformation energy consumption of the elastic deformation element. The elastic deformation element is impinged on the actuator during excessive force effect and impinges the plastic deformation element of the actuator.

Description

The The invention relates to an electrical switch according to the preamble of claim 1.

It are diverse embodiments of electrical switches, in particular in the form of buttons and Keyboards known. The switch according to the invention starts from a housing in which an actuator in the form of a print head is linearly inwardly movable. In the pressed state of the actuator includes or at so-called normal closed-buttons - this opens an electric Switching contact.

One Problem with such switches is the so-called vandalism, So the protection of the switch in case of violence. Be here from the market ever higher Requirements for the degree of protection against impacts.

Out For this reason, it is known, the above-described electrical Switch with an elastic damping element to equip, which is an excessive force to dampen on the actuator. These elastic damping elements can while compensating to an extent for excessive force, Nevertheless, the force in daily practice can be so great that the Deformation energy of the elastic damping element is insufficient for the forces receive. It then comes due to the introduced energy irreversible deformations and destruction with the consequence of functional failures.

From the EP 1 603 012 A2 For example, a keyboard is known in which an actuator is arranged in a front panel. Below this actuator, an electrical switch is arranged.

Under this in turn a support plate is provided. To create a vandalism protection is below this support plate an elastic device in the form of a planar structure in particular in the form of a thermal plastic gel.

The DE 28 37 461 C3 also shows a button with a vandal protection. In this case, the actuator is supported on the side facing away from the actuator plate side to a repository with non-linear compliance. This repository gives it when crossing conventional actuation forces acting on the actuator plate, elastic and thus prevents destruction by excessive pressure forces.

The DE 296 09 977 U1 shows an illuminated button, especially for key units of intercoms. In this case bellows seals are provided which act on the one hand as damping and which on the other hand return the key to its rest position when it is released.

The EP 0 473 934 A1 shows a vandal resistant push button element. A radially projecting shoulder of a push button comes to a corresponding stop of the housing to plant.

The DE 20 2007 003 190 U1 shows an actuator for an electrical or electronic switching element. To increase the vandalism, the actuator is made of a ceramic.

Of the Invention is therefore based on the object, the electrical switch develop the type specified above such that the so-called Vandalism protection is even further improved.

The technical solution is characterized by the features in the characterizing part of claim 1.

The Basic idea of the electrical according to the invention Switch is in a 2-stage actuator damping. This way will by using elastic and plastic deformation energies a higher vandal protection achieved. The damping the actuator forces thus two-stage. In the first stage is done by the elastic damping element one - concerning the Damping element - non-destructive low energy absorption. In the second stage is due to the plastic damping element a high energy absorption. Since this element is plastic, is this high energy absorption due to the deformation irreversible. Consequently let yourself with this system a high vandalism protection he aim. Should be an overload take place, so can with a corresponding constructive training of the electrical switch the plastically deformed damping element be replaced without having to replace the entire switch.

The Training according to claim 2 hits before, that off the time from which the plastic damping element acted upon by the actuator is, the elastic damping element continues also remains charged. This will add an additive energy achieved.

According to the training in claim 3, it is in the elastic damping element preferably a rubber or plastic. Other materials, which elastic damping properties are equally conceivable.

at the plastic damping element acts it according to the training in claim 4, preferably to metal, for example to copper. Other Metals are basically also conceivable.

A preferred training proposes according to claim 5 before that it Both in the elastic damping element as well as in the plastic damping element each dealing with O-rings. These have the advantage that these cheap in the Trade available are so that the inventive switch economical is feasible.

A Another preferred embodiment proposes according to claim 6 that the O-rings in terms of the central axis of the actuator are arranged concentrically. This will be a compact design created. The underside of the mushroom-shaped actuator lies in the Applying force to the O-rings.

A preferred development thereof proposes according to claim 7, that the O-ring the elastic damping element a larger cross-sectional diameter has as the O-ring of the plastic damping element. Under the "cross-sectional diameter" is not the outside diameter to understand the O-ring, but the diameter of the ring as such in a section perpendicular to the circle center line of the ring. This means that when pushing down of the actuator first the bottom of the actuator's head on the upper generatrix the elastic damping element incident. After then the actuator performs a certain stroke then hits the underside of the actuator on the upper surface line the plastic damping element.

Finally, the training suggests according to claim 8 that the Place O-rings on a platform of the housing. The housing forms in a sense a kind of pot, on the bottom of which are the two O-rings.

One embodiment an electrical according to the invention Switch will be described below with reference to the drawings. In this shows:

1 a side view of the switch, partially cut;

2a to c different positions of the actuator when pushing down.

The button has a housing 1 on, which in the upper part cup-shaped with a central axis substantially perpendicular platform 2 is trained.

In the case 1 is linearly displaceable an actuator 3 stored. This is mushroom-shaped with an axial guide rod 4 as well as with an actuator plate 5 at the upper end of the guide rod 4 educated.

Concentric around the central axis of the switch is inside a plastic deformation element 6 arranged in the form of an O-ring made of a metal, in particular copper. In the outdoor area of the platform 2 is an elastic damping element 7 also in the form of an O-ring, but here stored in rubber or plastic.

The How it works is as follows:

1 such as 2a show the basic position. The actuator plate 5 of the actuator 3 lies on the O-ring of the elastic deformation element 7 on. Since the cross-sectional diameter of the O-ring of the plastic deformation element 6 is less than the corresponding diameter of the elastic deformation element 7 there is still a gap here.

When pushing down the actuator 3 ( 2 B ) becomes the elastic deformation element 7 elastically compressed, combined with a low energy absorption by the elastic reversible deformation. 2 B shows the situation where the actuator plate 5 just before touching the O-ring of the plastic deformation element 6 stands.

Will the force on the actuator 3 even bigger ( 3 ), the O-ring of the plastic deformation element becomes 6 also deformed, namely plastically deformed, associated with a high energy consumption. When the force stops, moves the elastic deformation element 7 due to its reversibility the actuator 3 back to the starting position, due to the irreversible plasticity of the plastic deformation element 6 However, this O-ring remains in its deformed shape.

However, after this "vandal attack" on the electric switch, the O-ring of the plastic deformation element 6 be replaced so that the vandalism protection is restored.

1

casing

2

platform

3

actuator

4

guide rod

5

operating plate

6

plastic deformation element

7

elastic deformation element

Claims (8)

Electric switch with a housing ( 1 ), with one in the housing ( 1 ) linearly movable actuator ( 3 ), which closes or opens in the pressed state an electrical switching contact, and with a between the housing ( 1 ) and the actuator ( 3 ) arranged elastic deformation element ( 7 ) for damping an excessive force on the actuator ( 3 ), characterized in that in addition to the elastic deformation element ( 7 ) nor a plastic deformation element ( 6 ) for damping the excessive force on the actuator ( 3 ), wherein the deformation energy absorption of the plastic deformation element ( 6 ) is greater than the deformation energy input of the elastic deformation element ( 7 ) and in the case of an excessive force acting on the actuator ( 3 ) first the elastic deformation element ( 7 ) and then the plastic deformation element ( 6 ) from the actuator ( 3 ) can be acted upon. Switch according to the preceding claim, characterized in that when the plastic deformation element ( 6 ) also the elastic deformation element ( 7 ) from the actuator ( 3 ) can be acted upon. Switch according to one of the preceding claims, characterized in that the elastic deformation element ( 7 ) made of rubber or plastic. Switch according to one of the preceding claims, characterized in that the plastic deformation element ( 6 ) consists of metal. Switch according to one of the preceding claims, characterized in that it is in the elastic deformation element ( 7 ) and in the plastic deformation element ( 6 ) are about O-rings. Switch according to Claim 5, characterized in that the O-rings are movable relative to the central axis of the actuator ( 3 ) are arranged concentrically. Switch according to claim 5 or 6, characterized in that the O-ring of the elastic deformation element ( 7 ) has a larger cross-sectional diameter than the O-ring of the plastic deformation element ( 6 ). Switch according to one of Claims 5 to 7, characterized in that the O-rings are mounted on a platform ( 2 ) of the housing ( 1 ) rest.