EP2048676A2 - Sliding contact switch - Google Patents

Abstract

The electrical sliding contact switch has zones (18) in the sliding path (12) where they do not touch the sliding contact (8) while passing over the sliding zone (20). At least one rib or groove (16) is in the sliding zone.

Description

The invention relates to an electrical sliding contact switch, in particular a micro, miniature or subminiature switch whose switching positions are changed by sliding movement of the contact body.

Electrical sliding contact switch of this type serve as micro, miniature or subminiaturschalter in many applications, such. B. in the automotive and home appliance technology. In these switches sliding contacts are brought in a sliding movement of a contact point to another contact point. The electrically conductive connection should be made only at the respective contact points.

Out DE 10 2006 011 930 B3 is an electrical sliding contact switch with a pivotally mounted contact rocker known. The known switch has a base of electrically insulating plastic and a lid. The voltage is applied to a common contact body, which is constantly in electrically conductive connection with a contact rocker mounted on it. The contact rocker has two pairs of contact fingers that sweep contact areas on two select contact bodies. A positioning spring in C or Ω form pulls the contact rocker into a first oblique position, in which the shift fingers rest on both sides against the contact region of the first selection contact body. By pressure on an actuator, which is displaceable in the lid and sealed by a sealing sleeve, the contact rocker is forced into its opposite second pivotal position in which abut the contact fingers on both sides of the contact region of a second selective contact body.

EP 1 764 813 A1 describes an electrical switch having a common contact body as well as a first selective contact body and a second elective contact body. With the common contact body, a contactor is mechanically and electrically connected. The contactor consists of an elastic, electrically conductive material. The contactor is biased such that the contact fingers rest against the contact surfaces of the first select contact body. By pressure on the contactor of this is elastically deformed, and pivoted with the contact fingers so that the contact fingers comprise the contact surfaces of the second electroresistive switching effect.

A disadvantage of the switch of the prior art is that by the sliding movement of the sliding contacts on the housing areas between the selective contact bodies metallic Deposits may occur, which can even make a conductive connection between the individual Wahlkontaktkörpern. These deposits are reinforced by contamination and by the burning of the lubricating grease or oil used, so that the grinding path, which is formed by the sliding contacts in the grinding region of the housing, can make a conductive connection.

With progressive wear of the sliding contacts, which preferably have a spherical segment shape in their original state, the sliding contacts in the switch of the prior art become ever flatter, so that the initial point contact of the sliding contacts with time passes into a surface contact. This has the effect that the contact pressure / surface pressure of the sliding contacts on the selector contact bodies is getting smaller, since the contact surface of the sliding contacts is getting larger, and therefore an ever poorer contact reliability is achieved.

However, the flattening of the sliding contacts with increasing wear also has the consequence that the switching point shifts, since the bearing surface is larger. In extreme cases, this may lead to a simultaneous contact of a sliding contact on two selective contact bodies, and lead to a short circuit. To avoid this, the distance between the selection contact bodies must be chosen so large that this effect is taken into account. This results in the new state to long Umschaltwegen (dead paths) in the switch, with the service life, i. with increasing wear of the sliding contacts, become shorter. This also results in a decreasing switching time with the service life of the switch, i. the switching times of the known switch can not be kept constant. This results in relatively large switching point tolerances, which must be maintained over the life of the switch.

The invention is therefore based on the object to provide an electrical switch of the type mentioned, in which the switching operation can be optimally designed according to the electrical and mechanical requirements, so that, despite economical production, a long-term reliable continuous operation is guaranteed.

The solution of this problem is achieved by an electrical sliding contact switch with the entirety of the features of claim 1. Further developments of the invention will become apparent from the dependent claims.

Starting from the generic switch according to DE 10 2006 011 930 B3 In the switch according to the invention, a contactor between selector contact bodies is brought dragging from a switching position to another switching position. Here is the contactor with one end constantly in electrically conductive connection with a common contact body, which usually represents a ground terminal. On the contactor sliding contacts are formed, which make electrical contact with Wahlkontaktkörpern in the respective switching position. Upon actuation of the actuation switch or -gliedes these sliding contacts are brought out of engagement with a first selector contact body and slidingly into engagement with a second selector contact body, wherein between the two selector contact bodies of the sliding contact is passed over a grinding area. Not necessarily, the switch according to the invention has two selector contact body. The sliding contact switch according to the invention can also have, for example, as a simple on / off switch only one selector contact body, wherein the sliding contact is reciprocally coupled between an electrically non-conductive grinding region and the contact surface of a selector contact body.

Thus, in the operation of the switch by frequent switching back and forth between the Wahlkontaktkörpern and the grinding area no contact or trace on the grinding area is built up by the abrasion of the sliding contact, the contact track or the contact tracks of the sliding contact / the sliding contacts are deliberately interrupted. This is done according to the invention for example by introducing a rib or a groove in the grinding area, which crosses the slideway. Such a design of the grinding area between two selector contact bodies or the selector contact body and a non-conductive basic position of the sliding contact the continuity of the grinding path is avoided. This can be produced by deposits, which may be metallic abrasion of the sliding contacts and / or dirt, no electrical connection between the selector contact bodies.

By arranging a rib transversely to the direction of movement of the sliding contacts, it is achieved that in the region of the transition of the grinding surface to the surface of the rib, the sliding contact does not touch the rib in the connection region to the grinding surface, ie at the foot of the rib, during the passage of the sliding contact over the rib. The sliding contact can not penetrate to the bottom of the rib due to its crowned shape, with a radius which is greater than the radius of the point of attachment of the rib to the grinding surface. This creates on both sides of the rib in each case an interruption in the grinding path, in which abrasion and / or impurities can not make a conductive connection. A formation of a conductive connection between the election contact body over the rib away is thus not possible. At the same time, the contact point of the sliding contact changes continuously as it traverses the rib so that possible abrasion occurs uniformly over the entire surface of the sliding contact.

Although the shape of the rib can be determined largely freely, it must nevertheless be ensured that the sliding contact and the rib are designed so that at the moment in which the sliding contact touches the rib and not yet lifted from the grinding area, a gap remains between sliding contact and ribbed bottom, in which the sliding contact can not penetrate. This gap interrupts, as already indicated above, on the one hand, the sliding track between the selector contact bodies and on the other hand can accumulate in this gap grease or oil and thus improve the lubrication of the sliding contact. Lubricating grease used will preferably accumulate in the bottom of the rib and spread along the rib, so that lubricating oil or grease can be absorbed to lubricate the sliding contact each time the sliding contact is brushed away.

What was described above in the example of a rib in the switching area of the housing, applies analogously or correspondingly also for grooves that are introduced into the grinding area. Unlike the embodiment with protruding from the grinding area ribs, in which the grinding path is interrupted on both sides of the rib, the grinding path is interrupted only once when introducing a groove in the grinding area. In the groove base, which is not touched by the sliding contact, no mechanical contact takes place through the sliding contact, and thus can not be made a merger of the abrasion to a conductor track here. The shape of the groove can be chosen arbitrarily, as long as it is ensured that the sliding contact can not penetrate into the groove base.

As with the execution of rib-like bulges or protrusions from the grinding area, accumulates in groove-like recesses, the lubricating oil or grease used. Thus, the groove for the lubricant used also acts as a kind of reservoir.

By introducing grooves and ribs is achieved as a further advantage tactile feedback that occurs when the sliding contact over the groove or the rib. This can be used to detect a switching state, for example, a basic position of the switch. When performing a constriction, this is particularly easy because the sliding contacts are pressed easily into the indentation due to their contact force and an increase in the resistance to movement for further movement of the sliding contacts can be seen.

Thus, for example, a center-zero position is detectable, which may be a basic position for the switch. But even by sequential arrangement of two ribs can achieve such an effect. Here, the tactile feedback can be utilized by crossing the sliding contact of the first rib to determine after leaving the selection contact a non-conductive position of the sliding contact and vice versa after leaving the Abrasive area a conductive connection can be detected on a dial contact body. Thus, a switch position with conductive electrical connection or a position with non-conductive connection can be determined in a simple and reliable manner. Thus, for example, in a so-called center-zero position, the non-conductive grinding region, which is also referred to as an insulator, arranged between two conductive regions, each associated with a selective contact body or even belong to a single contact body (selector contact body). In the center zero position, the sliding contact of the contactor is located on the grinding area of the insulator, so that no passage takes place in the switch.

With the invention, all known switching positions or switching states can be realized, as with switches, which are known from the prior art, in particular, the sliding contact can be brought from a position on a non-conductive grinding area in a conductive contact region on a (optional) contact body be moved from there to another grinding area, for example, another insulator, or back to the (output) insulator. The switch according to the invention can also be made of a switching or normal position, in which the contactor is in conductive connection with at least one sliding contact with a selective contact body, and thus a passage through the switch takes place over a grinding range, during which no passage through the switch takes place be moved to another dial contact body, in which case again takes place a passage through the switch. In this case, the contactor with a different contact point with a common contact body for the contact body, which usually represents the ground contact of the switch, in constantly electrically conductive connection.

By introducing at least one rib or groove, the switching point can be precisely defined from one selection contact body to another elective contact body, since in addition to the movement running in the plane of the grinding regions, a movement directed away from the grinding surface is added, which permits a defined switching point. This additional movement can also be achieved that the distances between the selector contact bodies can be optimally designed so as to enable a faster and more accurate switching. In addition, the switching path remains largely constant regardless of the number of switching cycles. A shortening of the dead travel due to the flattening of the initially crowned sliding contact and the associated increase in the contact surface is practically not in the switch design according to the invention.

With regard to the design of the contactor with its sliding contacts and its movement possibilities, ie the sliding contacts on the grinding path in the grinding area a variety of possibilities can be implemented, which are all encompassed by the inventive concept, as long as the trajectory / sliding track, the sliding contact in electrically non-conductive Abrasive region is interrupted by introducing an elevation or depression, so that zones in the grinding area and / or on the surface of the elevation or depression are present, which does not touch the sliding contact. Since the idea of the invention allows already existing electrical circuit breaker concepts to change according to the concept of the invention, such modified electrical contact switches are also included in the inventive concept.

The invention is likewise not limited to switches which switch back and forth between two selector contact bodies with an electrically nonconductive grinding region arranged therebetween or switch from an electrically non-conductive grinding region into an electrically conductive region and vice versa, but it is readily apparent to the person skilled in the art that the concept of the invention can also be applied in rotary sliding contact switches, potentiometers or rotary switches. The same applies to linear switches with a purely linear movement of the contactor or the sliding contacts from a first position to a second position. Of course, switches that perform a combination of linear and rotary movements of the sliding contacts and thereby run over elevations or depressions in non-conductive areas, also included in the inventive concept.

The manner in which the contactor is brought from a contact point on a selector contact body over the barrier on the grinding region of the housing to another contact point of a selector contact body is included in the invention in all possible embodiments. It does not matter whether the contactor is elastically biased or elastically brought into a biased position or simply pushed without elastic deformation of a range in the next area, pulled or rotated. In all these cases, the inventive concept is also realized when between two switch positions for a sliding contact a geometric obstacle, for. B. is introduced in the form of a rib or a groove which interrupts the slideway, so that between two adjacent areas no conductive connection is established by the slideway.

Figur 1

eine räumliche Darstellung eines erfindungsgemäßen Schalters mit abgenommenem Schalter.

Figur 2

eine vergrößerte Detailansicht aus Figur 1, in der der Bereich zwischen zwei Schaltstellungen dargestellt ist.

Figur 3

eine Seitenansicht eines Schleifbereiches zwischen zwei Wahlkontaktkörpern mit einer eingebrachten Nut.

Figur 4

eine Seitenansicht eines Schleifbereiches zwischen zwei Wahlkontaktkörpern mit einer eingebrachten Rippe.

Figur 5

eine Seitenansicht eines Schleifbereiches zwischen zwei Wahlkontaktkörpern mit zwei eingebrachten Rippen.

The invention and further developments of the invention will be explained in more detail below with reference to the drawings of an embodiment. In the drawings show:

FIG. 1

a spatial representation of a switch according to the invention with removed switch.

FIG. 2

an enlarged detail view FIG. 1 , in which the area between two switching positions is shown.

FIG. 3

a side view of a grinding area between two Wahlkontaktkörpern with an introduced groove.

FIG. 4

a side view of a grinding area between two Wahlkontaktkörpern with an inserted rib.

FIG. 5

a side view of a grinding area between two Wahlkontaktkörpern with two introduced ribs.

FIG. 1 shows a sliding contact switch, as it is known from the aforementioned prior art, but with an introduced in the grinding area rib. The switch shown has a housing 2, in which a common contact body 4 and two selective contact body 10 are arranged with their broad sides flat next to each other so that in each case one end of the three contact body protrudes from the housing. In the housing 2, the common contact body 4 and the two selector contact body 10 are arranged or embedded in the housing 2 such that there is no conductive connection between them. A contactor 6 is in constantly conducting electrical connection with the contact body 4. The contactor can be switched by an actuator 14 elastically between the contact surfaces 11 of the selector contact body 10 back and forth. In this case, the contact surfaces 11, which are located on both sides of the selection contact body 10 of contact fingers 22, which are located on the contactor 6, comprises elastically biased. By pressing the actuator 14 into the switch into the Schleiffinger 22 are moved by a first selector contact body 10 grinding a grinding area 20 to a second Wahlkontaktgeber 10.

As in detail FIG. 2 As can be seen, the wiper fingers 22, as they move from one selector contact body to the other selector contact body, cross a rib 16 which is arranged in the grinding region 20 approximately transversely to the direction of movement. In FIG. 2 is shown in dashed lines, the respective sliding track 12 for the sliding contacts 8. It can be seen that the slideway 12 is interrupted in each case before and after the rib, as seen in the direction of movement of the Schleiffinger 22.

How very good of the Figures 3 and 4 As can be seen, these interruptions 18 occur in the grinding path 12 in that in these zones, the Schleiffinger 22 have no contact with the grinding area 20.

In FIG. 4 the two Schleiffinger 22 are shown in the position in which they just touch the rib 16. With further progression of Schleiffinger 22 in the direction of in the FIGS. 3 and 4 indicated arrow lifting the Schleiffinger 22 from the grinding area 20 and cross the rib 16. At the moment of contact of the contact fingers 22 with the rib 16, as in FIG. 4 shown, contact-free zones 18 are present between the contact fingers 22 and the grinding area 20, in which the sliding contact 8 can not occur. The sliding contact 8, which in the illustration according to FIG. 4 still touches the selector contact body 10, moves away from the grinding area 20 when continuing the contact fingers 22. Thus, the contact finger 22 moves its point of contact to a support point, which is seen in the direction of movement further forward.

With continuation of the contact fingers in the direction of arrow can be turned off FIG. 4 recognize well how this contact point of the Schleiffinger 22 on the rib slowly moves backwards seen in the direction of movement. At the end of the rib 16, the contact fingers rest against the grinding area due to their inherent biasing force and can then be further moved in a sliding movement toward the second selection contact body 10.

In a further embodiment, the in FIG. 5 is shown, two ribs 16 are provided in the grinding area 20, which, for example, can serve to hold the Schleiffinger 22 in a defined position. From this, they can then be deflected in both directions in order to enter into a conductive connection with both the first selection contact body 10 and the second selection contact body 10.

The grinding region 20 is in this embodiment, a part of the housing, that is, the selective contact body are embedded in the housing so that the area 20 is filled between them by housing material. This can be realized, for example, in the injection molding process of the housing, wherein care must be taken that the contact surfaces 11 of the selector contact body are not covered with injection molding material. Simultaneously with the embedding of the selector contact body in the housing and the rib 16 and the groove 16 may be formed, in FIG. 3 is shown.

The embodiment according to FIG. 3 shows how the already FIG. 4 the principle of the sliding moving contact fingers of a selective contact body 10 via a grinding area 20 to a second dial contact body 10. In this case, the sliding contacts 8, which are attached to the contact fingers 22, a groove 16 in the groove bottom, the groove 16 zones 18, which of the sliding contacts 8 can not be achieved. As a result, the sliding track of the sliding contacts 22 is interrupted simply and reliably here by a design measure.

The principle of interruption of the slide tracks by non-contact zones 18 is shown here using the example of a NO / NC switch, but this represents only one of a variety of embodiments.

LIST OF REFERENCE NUMBERS

2

casing

4

common contact body

6

contactor

8th

sliding contact

10

Selective terminal

11

contact area

12

sliding track

14

actuator

16

Groove rib /

18

non-contact zone

20

grinding area

22

sanding finger

Claims (10)

Electric sliding contact switch comprising a housing (21) in which are arranged: a common contact body (4), at least one selection contact body (10) having a contact surface (12), a grinding region (20) consisting of electrically insulating material, adjacent to the contact surface (11) of the electropolishing contact body (10), - A contactor (6) having a contact in constantly electrically conductive connection with the common contact body (4) and at least one sliding contact (8) which is in electrically conductive connection with the selective contact body (10) or the grinding area (20 ) touched, - An activatable actuator (14), which upon actuation the at least one sliding contact (8) of the contactor (6) on a grinding path (12) from the contact surface (11) of the selector contact body (10) in the grinding area (20) and / or moved from the grinding area (20) to the contact surface (11) of the electrowitch body, characterized,
in that zones (18) are formed in the grinding path which are not touched by the sliding contact (8) during the travel of the grinding area (20). Sliding contact switch according to claim 1, wherein at least one rib (16) or a groove (16) is arranged in the grinding region (20). Sliding contact switch according to claim 1 or 2, wherein the common contact body (4) and the at least one selection contact body (10) are designed in the form of flat disc-shaped body, which form a common plane with their broad sides for the arrangement in a row. Sliding contact switch according to one of claims 1 to 3, wherein the contactor (16) is elastically deformed upon activation of the actuating member (14). Sliding contact switch according to one of claims 1 to 4, in which the activatable actuating member (14) and the contactor (6) automatically return to their initial positions after actuation. Sliding contact switch according to one of Claims 1 to 5, in which the sliding contacts (8) of the contactor (6) are in a basic position in a grinding region (20) between two adjacent selective contact bodies (10). Sliding contact switch according to one of claims 1 to 6, wherein the sliding track (12) from a first selection contact body (10) to a second selection contact body (10) is substantially curved or rectilinear. Sliding contact switch according to one of Claims 1 to 7, in which the contactor (6) has pairs of sliding contacts (8) which adjoin one another and between which a selection contact body (10) can be received. Sliding contact switch according to one of Claims 1 to 8, in which the sliding contacts (8) on the contactor (6) are designed as sliding contact fingers. Sliding contact switch according to one of Claims 1 to 9, in which the contact surfaces (11) of the selector contact bodies (10) are arranged annularly and are separated from one another by grinding regions (20).

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