ES2951583T3 - Switching device - Google Patents

Abstract

In a device (1) as an interface for an electrically driven machine tool or other electrical device and a person for converting a mechanical feed movement (2) into an electrical switching signal (12), consisting of: a housing (3) in which at least one notch (4) is incorporated, an elastic disc (9) kept pre-tensioned in the housing (3) and arranged in the area of the notch (4), which in the non-actuated state is bulging in the direction of the opening of the recess (4) and a printed circuit board (10) arranged in the housing (3), which is formed by electrically conductive tracks (21, 22, 23, 24), the elastic disc (9) being activated ) comes into active electrical contact with two conductive tracks (23, 24). At least two electrical control signals should be generated by means of an elastic disc (9). This is achieved because four of the existing conductive tracks (21, 22, 23, 24) are spatially separated from each other and connected in pairs and each pair of conductive tracks (21, 22,) or (23, 24) form a circuit in in which two separate support bodies (25, 26) are provided perpendicular to the four conductive tracks (21, 22, 23, 24), which are arranged in a plane between the four conductive tracks (21, 22, 23). , 24) and the spring disc (9), and that the spring disc (9) is supported by the support body (25, 26) as a rocker during the forward movement, in such a way that it is oriented towards the support. The bodies in the outer extension area (25, 26) of the spring disc (9) are lifted from the first and second driving tracks (21, 22) and at the same time the spring disc (9) rests on the third and inner room. conductive tracks (23, 24) and is electrically connected to them. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Switching device

The invention relates to a switching device as an interface for an electrically operated machine tool or other electrical apparatus and a person for converting a mechanical feed movement into an electrical switching signal according to the preamble of claim 1.

Such switching devices have been proven in the past as an interface between people and electrically operated devices or machine tools since they generate control signals when a mechanical forward movement is made towards them. The constructive structure and operation of such switching devices can be extracted, for example, from document EP 1750 291 B1. The switching devices consist of a housing in which a printed circuit board with contact or conductive tracks is present. One or more recesses are made in the housing. A press-fit disc made of an electrically conductive material that is pre-tensioned is inserted into the respective recess. Such press fit discs are curved outwards in particular in a dome shape so that the press fit discs protrude from the plane formed by the housing surface and are therefore freely accessible from outside and can therefore be mechanically actuated. . The outwardly protruding contours of the press fit discs can be covered by switching mats or other drive elements. Therefore, the contour of the switching surface can be distinguished both by touch and visually.

The pressure-fit disc or the operating lever arranged above consequently forms a switching surface. Each switching surface can be assigned a specific control function, which the respective person as user can distinguish by means of symbols or inscriptions.

A printed circuit board is arranged inside the housing, which has two switching contacts. These switching contacts usually protrude from the plane formed by the printed circuit board in the direction of the press fit discs. As soon as the press-fit disc has been bent by a mechanical feed force acting accordingly on it in the direction of the printed circuit board, the underside of the press-fit disc bridges the distance between both contact contacts. switching printed circuit board. Therefore, an electrical short circuit arises by which an electrical switching signal is generated and transmitted for control to a machine tool or other electrical appliance. The switching contacts are accordingly arranged in the area of maximum bulge of the press fit disc and run directly aligned below the curvature of the press fit disc. As soon as the manual feed force no longer acts on the press fit disc, the press fit disc rebounds to its initial position due to the pre-tension stored in it.

It has proven to be disadvantageous in this construction that a press-fit disc can exclusively generate an electrical switching signal, since the press-fit disc either bridges the distance between both switching contacts and thus generates the switching signal or The press fit disc is raised or spaced away from both switching contacts so that this electrical contact opens.

Document DE 2531841 A1 discloses a quick-acting switch with an elastic plate that, when applied under pressure by an actuating element, jumps from a stable position to a metastable position and therefore opens or closes contacts. In the unpowered state the outer conductors are electrically connected, while in the powered state one of the outer conductors is electrically connected to an additional inner conductor. Since one of the outer conductors in both the non-driven state and the driven state is part of a closed electrical circuit, no complete separation of the electrical circuits is realized.

US 2011/233037 A1 discloses a switching device with an elastic drive disc that can be translated from a non-driven state to a driven state. In the non-driven state, current-carrying contact rings are electrically connected across the drive disc and the electrical circuit is closed by resting the ends of the drive disc on the outer contact ring and the support legs radially inwardly offset. the underside of the drive disc on the inner contact ring. In the pressed-down driven state the ends of the drive disc are lifted from the outer contact ring so that the electrical circuit is interrupted. The support legs on the underside of the drive disc have both the function of a current-conducting element and the function of a counter support.

The invention is therefore based on the object of perfecting a switching device of the generic term mentioned at the beginning in such a way that at least two electrical control signals can be generated by means of a press-fit disc.

This objective is solved by the characteristics of the characterizing part of patent claim 1.

Other advantageous developments of the invention emerge from the dependent claims.

Since the four of the existing conductor tracks are spatially separated from each other and are interconnected in pairs and each pair of the conductor tracks form a switching circuit, two support bodies are provided perpendicular to the four conductor tracks, spaced apart from each other. another that they are arranged in a plane running between the four conductive tracks and the press fit disc, and that the press fit disc during the forward movement is supported by the supporting body as a rocker in such a way that the area of the press-fit disc running outside towards the support bodies is raised from the first and second conductive tracks and at the same time the press-fit disc rests on the third and fourth inner conductive tracks and is connected electrically with these, it is achieved that the press-fit disc contacts and short-circuits both in its initial position and in its press-fit position pushed inward in each case different conductive tracks. This respective short circuit can be detected by control equipment and converted into an electrical switching signal. Consequently, an electrical contact of the outer conductive tracks with the legs located in each case in the corner areas of the press-fit disc occurs, while in the operation of the press-fit disc by lifting the legs of the outer conductive tracks this contact opens, while the contact closes by the side-to-side oscillation of the press-fit disc on the center conductive tracks and consequently short-circuits the two center conductive tracks along their separation at the center .

When the printed circuit board consists of four conductor tracks spatially separated from each other that have the corresponding arrangement of switching contacts and when between the switching contacts of the first, second and third or fourth conductor tracks and between the center of The housing and the housing edge are supporting bodies at right angles to the conductive tracks, on which the press-fit disc rests in the manner of a rocker arm, then or the marginal areas of the press-fit disc in the thrust inwards are lifted from the respective outer conductor tracks and both switching contacts provided in the center are short-circuited by the press-fit disc or the press-fit disc short-circuits the outer conductor tracks in the non-actuated state, since this does not rests on the respective conductive tracks, so that each press-fit disc thereby generates two different switching signals.

The movement of the press-fit disc defined in this way, in particular its corner regions, when the press-fit disc bulge is pressed downwards in the direction of the two central conductive tracks leads to two different switching situations, to which A different switching signal can be assigned in each case.

It is particularly advantageous to manufacture the printed circuit board and its four conductive tracks as a patterned grid of an electrically conductive material and then extrusion coat or coat this patterned grid with a material that acts electrically insulating, for example plastic. In this regard it should be noted that areas of the conductive tracks that are directed to the subsequently mounted snap-fit discs are not covered by the insulating material but rather are freely accessible. These freely accessible areas of the conductor tracks serve specifically as switching contacts for the press-fit discs and to generate the respective short circuits. The stamped grating coated by extrusion in this way can be manufactured affordably and accurately, since by means of extrusion coating the housing and the accommodation opening necessary for the accommodation of the press-fit discs are formed, into which the disc of pressure is inserted. respective snap fit and is retained oriented in position.

An example of an embodiment according to the invention is represented in the set of drawings, which is explained below in more detail. In detail, they show:

Figure 1 shows a switching device composed of a housing in which an essentially rectangular recess is made, a pressure-fitting disc arranged in the recess and four conductive tracks spatially separated from each other, in a perspective view,

Figure 2 is a top view of the switching device of Figure 1 with two support bodies running parallel and perpendicular to the four conductive tracks that are formed in the housing and running between the conductive tracks and the press fit disc,

Figure 3a shows the switching device according to Figure 1 in parallel section and in the area of the central conductor tracks in the non-actuated state and,

Figure 3b the switching device according to Figure 3a in the activated state and

Figure 4 shows a manufacturing procedure for the conductive tracks designed as a stamped grid and its housing for a device according to the aforementioned figures.

From Figures 1 and 2, a switching device 1 can be seen as an interface for a not shown electrically operated machine tool or other electrical apparatus and a person for converting a mechanical feed movement 2 into an electrical switching signal. The device 1 is composed of a housing 3 and an essentially rectangular recess 4 made therein. A drive element 5 housed therein in an axially movable manner is fixed to the recess 4.

A press fit disc 9 is arranged between the drive element 5 and the closed lower side of the housing 3, which is made of an electrically conductive material. The press fit disc 9 has a dome-shaped bulge which is designed in the direction of the drive element 5 and cooperates with it as will be explained in more detail below. The pressure-fitting disc 9 has legs designed as a dome in the outer area. The bulge of the press-fit disc 9 protrudes from the outer area or the legs.

In particular, it can be seen from Figure 2 that the housing 4 supports conductive tracks 21, 22, 23 as well as 24. Both first and second outer conductive tracks 21 and 22 run both parallel to each other and parallel to both facing walls of the recess 4. In the non-actuated state, the press fit disc 9 rests in the corner areas 15 with its legs on the outer conductive tracks 21, 22 and therefore forms a contact with the two outer conductive tracks 21 and 22. closed electrical circuit that is defined as the first electrical switching circuit.

The conductor tracks 21,22, 23 and 24 are located on a common plane.

Between the two outer conductive tracks 21 and 22, the two third and fourth inner conductive tracks 23 and 24 are provided and spatially separated from each other, which are arranged at a distance from each other in the area of the center 6 of the recess 4. In In the center area 6, the two conductive tracks 23 and 24 each have a switching contact 13, which in each case cooperates with the snap-fit disc 9 when the bulge of the snap-fit disc 9 moves or rotates in the center direction 6. The distance between both switching contacts 13 is consequently bridged by the snap-fit disc 9 and a short circuit occurs. This switching state is defined as second switching circuit.

Support bodies 25 or 26 are arranged perpendicularly to the conductive tracks 21, 22, 23 and 24. The support bodies 25 and 26 are configured in each case as a rib that is formed or fixed to the inner wall of the recess 4. The support bodies 25 and 26 run perpendicular to the four conductive tracks 21, 22, 23 and 24. Furthermore, the support bodies 25 and 26 are arranged between the press fit disc 9 and the conductive tracks 21,22, 23 and 24.

From Figures 3a and 3b the respective movement of the snap-fit disc 9 can be seen depending on manual advance forces acting on it. According to Figure 3a, the pressure adjustment disc 9 is in its initial position and a manual advance force 2 does not act on it. The legs of the press-fit disc 9 rest in the corner regions 15 of the recess 4 on the first and second outer conductor tracks 21 and 22 so that the respective first and second conductor tracks 21 or 22 are electrically short-circuited. using press-fit disc 9. This electrical switching state can be mediated via an electrical contact, such as a welded connection 14, in the outer area of the housing 4 at the ends of the outwardly guided conductor tracks 21, 22, 23, 24 and transmitted to a control device not shown for switching an electrical device and can be evaluated and converted there.

As soon as a mechanical feed force acts on the press fit discs 9 or the externally accessible drive element 5, for example by a human finger, the press fit disc 9 bends in the direction of the two third and fourth interior runways 23 and 24. The snap-fit disc 9, in particular its maximum bulge, is consequently snapped between both spring bodies 25 and 26 running parallel to each other and spaced apart in the direction of the conductive tracks 23 and 24, i.e. That is, it passes through the support body 25 and 26, and specifically until the lower side of the press-fit disc 9 rests on both switching contacts 13 of the inner conductive tracks 23 and 24. Due to the elastic bending of the press fit discs 9 generated in this way, both switching contacts 13 of the inner conductor tracks 23 and 24 are electrically short-circuited and at the same time the press fit disc 9 in the corner areas 15 It rises from both outer conductive tracks 21 and 22. Consequently, the switching state has been modified with respect to the initial situation according to Figure 3a (first switching circuit) and this modification of the switching state in the second switching circuit can be transferred through the electrical contact of the two conductive tracks 23 and 24 centrals in their end area outside the housing 3 on a printed circuit board to the control equipment or registered and evaluated by it. Both support bodies 25 and 26 consequently form a rotating or supporting surface for the press fit disc 9, whereby the movement of the press fit disc 9 in the direction of both conductive tracks 23 and 24 is not impeded. interior and at the same time the outer marginal areas of the press fit disc 9 in the corner areas 15 are raised from the outer conductive tracks 21 and 22. This movement can also be considered in the technical sense as a type of see-saw.

To improve the electrical connection between the snap-fit disc 9 and the respective switching contacts 12, 13 on the underside of the snap-fit disc 9 in its central area, a corresponding conformation in the form of a curvature or dome can be provided. .

A particularly affordable manufacturing method for the printed circuit board 10 is shown in Figure 4. The printed circuit board 10 is composed of a patterned grid 20 of an electrically conductive material. Accordingly, the four conductive tracks 21, 22, 23 and 24 must initially be positioned in a mold 19 oriented in position and then extruded or coated with a liquid plastic material 18. The mold 19 is designed in such a way that, on the one hand, the housing 3 with the recess 4 is formed and, on the other hand, certain areas of the conductive tracks 21, 22, 23 and 24 are not covered by the plastic 18 that acts in an electrically insulating manner, that is, they are freely accessible. These thus formed free surfaces of the conductive tracks 21, 22, 23 and 24 serve for the switching device 1 according to the invention as switching surfaces 12 and 13, since the press fit disc 9 in the non-actuated state rests on the switching surfaces 12 of both outer conductive tracks 21 and 22 - as explained above - and when the press fit disc 9 has been moved by manual advance force 2 in the direction of both conductive tracks 23 and 24 interior, the outer regions of the press fit disc 9 lift from the switching surfaces 12 and at the same time come into an active electrical connection with the switching surfaces or contacts 13 of both inner conductive tracks 23 and 24. Said bulging of the press fit disc 9 is made possible only by the two support bodies 25 and 26 present that form a type of rocker for the press fit disc 9.

By means of the manufacturing method according to the invention according to Figure 4, the support bodies 25 and 26 can be manufactured at the same time. The support bodies 25 and 26 run between the respective switching surfaces 12 of both outer conductor tracks 21 and 22 as well as both switching surfaces 13 of the inner conductor tracks 23 and 24 and are approximately the same distance apart. of the respective switching surfaces 12 and 13.

Claims (8)

1. Device (1) as an interface for an electrically operated machine tool or other electrical apparatus and a person for the conversion of a mechanical feed movement (2) into an electrical switching signal (12) consisting of: - a housing (3), in which at least one recess (4) is made, - a press fit disc (9) held pre-tensioned in the housing (3) and arranged in the area of the recess (4) which is bulged in the non-actuated state in the direction of the opening of the recess (4) and - a printed circuit board (10) arranged in the housing (3) which is formed by electrically conductive tracks (21, 22, 23, 24), wherein the press fit disc (9) in the actuated state enters in electrically active contact with two conductive tracks (23, 24), characterized because four of the conductive tracks (21,22, 23, 24) present are spatially separated from each other and are interconnected in pairs and each pair of conductive tracks (21,22, 23, 24) form a switching circuit, because perpendicularly to the four conductive tracks (21, 22, 23, 24) two support bodies (25, 26) are provided, spaced apart from each other, which are arranged in a plane that runs between the four conductive tracks (21, 22). , 23, 24) and the press fit disc (9), and because the press fit disc (9) during the forward movement is supported by the support body (25, 26) like a rocker in such a way that the area of the pressure fit disc (9) that runs on the outer side towards the support bodies (25, 26) is raised from the first and second conductive tracks (21, 22) and at the same time the Press-fit disc (9) rests on the third and fourth inner conductive tracks (23, 24) and is electrically connected to them. 2. Device according to claim 1, characterized because the first and second outer conductive tracks (21, 22) run parallel to each other, because the third and fourth inner conductive tracks (23, 24) are arranged parallel to the first and second conductive tracks (21, 22) and between these, because the third and fourth conductive tracks (23, 24) run aligned with each other and are oriented in the area of the center (6) of the notch (4) and there they are spatially separated from each other, 3. Device according to claim 1 or 2, characterized because the four conductive tracks (21, 22, 23, 24) are arranged in a common plane and because the outer perimeter of the press fit disc (9) in the non-actuated state rests on the conductive tracks (21, 22 ) first and second in the corner areas of the notch (4) on the outer conductive tracks 21 and 22. 4. Device according to one of the aforementioned claims, characterized because the support bodies (25, 26) are configured as ribs and because the ribs (25, 26) are fixed to the inner wall of the housing opening (4) of the housing (3) or are made in this . 5. Device according to one of the aforementioned claims, characterized because the pressure fit disc (9) is curved outward in the shape of a dome and is pretensioned against the direction of movement by the pressure piece (5). 6. Device according to one of the aforementioned claims, characterized because the printed circuit board (10) is manufactured as a stamped grid (20) composed of four conductive tracks (21,22, 23, 24). 7. Device according to claim 6, characterized because the stamped grid (20) is extruded or coated with an electrically insulating material, preferably plastic, because areas of the conductive tracks (21,22, 23, 24) are open or freely accessible in the direction of the press-fit disc (9) and because the freely accessible areas of the conductive tracks (21, 22, 23, 24) serve as switching surfaces (12, 13) for the press-fit disc (9). 8. Device according to claim 6 or 7, characterized because the support bodies (25, 26) are arranged between the switching surfaces (12, 13) and are spaced at the same distance with respect to the switching contacts (12) of the conductive tracks (21,22) first and second and the contacts (13) for switching the third and fourth conductive tracks (23, 24).