DE102023131721B3 - snap switch - Google Patents

Abstract

The present invention relates to a snap switch (100) with a housing (1), an actuating plunger (2) with two switching positions and two contact bridges (31, 32) for electrically connecting two pairs of fixed contacts (21, 22; 23, 24), wherein the first pair of fixed contacts (21, 22) is connected in the first switching position and the second pair of fixed contacts (23, 24) is connected in the second switching position, and with snap springs (8, 9) which are supported on an actuating element (3) and the actuating plunger (2) essentially symmetrically under prestress, the lines of action of which can be displaced by the actuating element (3) in such a way that the actuating plunger (2) can be snapped over, wherein the snap switch (100) further comprises a positive opening arrangement, wherein the two contact bridges (31, 32) each have at least two contact points (17, 18, 19, 20) for electrically parallel contacting of the first pair of fixed contacts (21, 22) or the second pair of fixed contacts (23, 24), wherein each of the contact points (17, 18, 19, 20) is designed to completely switch an electrical nominal power of the snap switch (100) and the actuating plunger (2) has a first stop (41) in the closing direction of the first pair of fixed contacts (21, 22) and a second stop (42) in the closing direction of the second pair of fixed contacts (23, 24), wherein the stops (41, 42) in cooperation with a first counter-stop (51) or a second counter-stop (52) limit a movement of the actuating plunger (2) in the closing direction of the first pair of fixed contacts (21, 22) or the second pair of fixed contacts (23, 24).

Description

The present invention relates to a snap switch according to the preamble of claim 1.

Snap switches are generally known from the prior art and generally have a housing, a contact bridge with two switching positions that can be switched via an actuating plunger for electrically connecting fixed contacts, in particular at least a first pair of fixed contacts in the first switching position and at least a second pair of fixed contacts in the second switching position. Two snap springs are supported essentially symmetrically under pretension on an actuating element and the actuating plunger, the lines of action of which can be displaced by the actuating element in such a way that the actuating plunger can be snapped from the first switching position, in which the actuating plunger is essentially in the rest position, to the second switching position, in which the actuating plunger is essentially in the actuating position.

Snap switches have in common that they work with a bistable snap spring arrangement, which results in a rapid switching movement when a certain switching point is exceeded. This rapid switching movement is intended to minimize arcing and thus damage to the contact elements. To provide this function, it does not matter whether the spring arms are designed as one piece with the contact bridge or as separate components.

A snap switch known from the state of the art is in 9 shown.

The snap switch shown has a housing 1 with a rectangular cross-section, which serves to accommodate the individual components of the snap switch. An actuating plunger 2 is arranged in the middle of the housing 1, which has a stop step inside the housing 1, which rests on an inner side of a wall of the housing 1 when the actuating plunger 2 is in the rest position. The actuating plunger 2 is pressed upwards into its rest position by a compression spring 4, so that the stop step 3 comes into secure contact. The actuating plunger 2 is guided in a sleeve-like receptacle in the area of the compression spring 4 and at an end opposite the compression spring 4 in a recess in the housing 1.

Approximately at the height of half of a longitudinal extension of the actuating plunger 2 located within the housing 1, the latter has two diametrically opposed receiving notches 7, i.e. in the present embodiment, mirror-imaged opposite one another, which are each designed to support a V-shaped snap spring 8, 9 on one side. A contact carrier 10 is held under prestress on the actuating plunger 2 via the snap springs 8, 9.

The other end of the snap springs 8, 9 is each received in a receiving notch 11, 12 of an insulating spacer 13, 14. The spacers 13, 14 hold an upper contact arm 15 and a lower contact arm 16 parallel to each other and spaced apart from each other. The contact arms 15, 16 are approximately O-shaped when viewed from above. The holding is achieved by arranging the snap springs 8, 9 under pre-tension between the actuating plunger 2 and the spacers 13, 14 so that the spacers 13, 14 are pressed against the contact arms 15, 16 and thus fix them in their position.

The contact arms 15, 16 have contact points 17, 18, 19, 20 arranged at the ends, wherein the contact points 17, 18, 19, 20 arranged on the contact arms 15, 16 are each assigned fixed contacts 21, 22, 23, 24 arranged opposite one another, so that one contact arm 15, 16 in the actuating position and the other contact arm 16, 15 in the rest position of the snap switch contacts the fixed contacts 21, 22, 23, 24 assigned to it and connects them to one another in an electrically conductive manner.

A first fixed contact 21 is assigned to a first contact point 17 and a second fixed contact 22 is assigned to a second contact point 18. The first fixed contact 21 and the second fixed contact 22 can thus be electrically connected to one another by the upper contact bridge 15 and form a first contact pair. Similarly, a third fixed contact 23 is assigned to a third contact point 19 and a fourth fixed contact 24 is assigned to a fourth contact point 20, so that the third fixed contact 23 and the fourth fixed contact 24 can be electrically connected to one another by the lower contact bridge 16 and form a second contact pair.

Since thermal overload of the contact points can lead to unwanted welding of the contact points of the contact arms with the contacts of the contact pairs, i.e. the fixed contacts, in some applications lever elements are provided for positive opening. In addition to the snap spring mechanism, the DIN EN 60947-5-1 standard in Appendix K prescribes such a rigid, positive opening for standard snap switches so that for safety reasons when the actuating element is operated element of the snap switch, the resting contact position is reliably opened. This forced opening is able to open contact points welded by excess current by applying the appropriate force. These lever elements can usually be swiveled over the switch plunger and one end can be placed on the contact carrier or the contact arms and, if sufficient force is applied to the switch plunger, lead to the contact points being pushed away from the fixed contacts and thus to a forced opening of the switch position. In order to make one of the switch positions the resting position, as in the example shown, 9 An additional spring element must be integrated into the snap switch in such a way that the position of the contact carrier in the rest position is stabilized by the force of the spring element.

The known snap switches are already very reliable and can be used for safety-critical applications. However, it is considered a disadvantage that they can fail electrically due to various effects, i.e. that the contact arms do not establish a conductive connection between the fixed contacts or do so only inadequately. Reasons for such a failure can include excessive contact resistance due to deposits of dirt or burn-off on the contacts, breakage of the snap springs or the contact bridge due to mechanical and/or thermal stress.

One reason for this degradation of the contact points 17 - 19 is the so-called bouncing of the contact bridge when it is transferred from one switching position to the other. Bouncing in this context describes a mechanically triggered interference effect when switching the snap switch.

Instead of an immediate and constant electrical contact, the switching of the contact bridge at high speed and the impact of the contact bridge on the fixed contacts causes the electrical connection to be closed and opened several times for a short time. The reason for this is that the contact bridge elastically rebounds from the fixed contacts. This repeated closing and opening of the electrical connection causes an electric arc at voltages of over 16 V and up to several hundred amps, which acts on the contact points 17 - 20 at temperatures of 10,000 °C to 15,000 °C and thus causes increased burn-off. The burn-off results in the contact points becoming dirty and thus in an increased contact resistance and a reduced service life of the contact points 17 - 20.

It is therefore the object of the present invention to improve a known snap switch in such a way that it has an increased service life and an increased availability or increased reliability when contacting the contact points with the fixed contacts.

This object is achieved by a snap switch with the features of patent claim 1. Advantageous further developments are the subject of dependent claims and the following description.

A snap switch according to the invention has a housing, an actuating plunger having two switching positions with at least one contact bridge for electrically connecting at least a first pair of fixed contacts in a switching position and with snap springs which are supported on an actuating element and the actuating plunger essentially symmetrically under prestress, the lines of action of which can be displaced by the actuating element in such a way that the actuating plunger can be snapped from a first switching position, in which the actuating plunger is essentially in the rest position, to a second switching position, in which the actuating plunger is essentially in the actuating position, wherein the snap switch further has a positive opening arrangement by means of which a switchover at least from the first to the second switching position is forced when a positive opening force on the actuating element is exceeded, wherein the actuating plunger has at least one first stop at least in the closing direction of the first pair of fixed contacts, which in cooperation with a first counter stop limits a movement of the actuating plunger in the closing direction of the first pair of fixed contacts.

The first stop and the first counter stop create an arrangement in which the movement of the actuating plunger is slowed down not only by the contact bridge, but also by the stop. The material and structure of the first stop and/or the first counter stop absorbs kinetic energy from the movement of the actuating plunger and dissipates it via the housing. By absorbing and dissipating the energy, the kinetic energy of the actuating plunger is reduced and not transferred back to it. This ensures that the actuating plunger and the contact bridges arranged on it bounce less, which increases the overall service life of the contact points and the contact bridges and thus of the snap switch as a whole.

By reducing the bounce, the service life of the contact points is increased, as they close and reopen less often and therefore arc less frequently, which reduces the burn-off of the contact points. On the other hand, the impact and the reduction in bounce increase the service life of the contact bridge, as it is bent less when the impact of the impact on the counter-attack occurs, and the number of alternating bending loads on the contact bridge is reduced by a smaller number of bounces.

Due to the stress conditions that constantly reverse in the rhythm of the alternating bending loads, in particular due to the respective tensile stresses, notches and cracks can appear on the surfaces of the contact bridge, which ultimately lead to the component breaking during the alternating bending load. The time of breakage depends on the level of the bending force and the resulting extent of the alternating elastic deflection of the component, and on the number of consecutive alternating loads. By reducing the bouncing of the contact bridge, the stability of the contact bridge is increased to the same extent as the bouncing is reduced. For example, the number of bouncing processes can be reduced from 5 to 2, preferably to 1 and ideally to 0, so that the stability increases to the same extent, i.e. it is tripled, quadrupled or quintupled.

Because part of the kinetic energy of the actuating plunger is absorbed and partly diverted by the stop, it is possible to make the contact bridge less massive than the state of the art, so that the mass of the contact bridge can be reduced. Because the contact bridge has a lower mass, the bouncing is also reduced.

The snap switch can be designed as an opener or a closer, whereby the rest position of the actuating plunger defines whether it is a normally closed contact, i.e. an opener, or a normally open contact, i.e. a closer.

The snap switch has two contact bridges for electrically connecting at least the first pair of fixed contacts and at least a second pair of fixed contacts, wherein the actuating plunger has a second stop in the closing direction of the second pair of fixed contacts, which, in cooperation with a second counter-stop, limits a movement of the actuating plunger in the closing direction of the second pair of fixed contacts.

By using two contact bridges with opposite closing directions, an arrangement is created in which when the electrical contact of the first pair of fixed contacts is opened, the electrical contact of the second pair of fixed contacts is closed, and vice versa. This makes it possible to switch two different electrical contacts, whereby when one contact is closed, the other contact is opened. If the snap switch is designed in such a way that the first pair of fixed contacts is connected in the first switching position and the second pair of fixed contacts is connected in the second switching position, the snap switch is implemented as an opener or a closer, depending on which fixed contacts are contacted from the outside.

By providing a stop in both closing directions, the bouncing of the actuating plunger in both directions is reduced and the positive effects described above are achieved for both contact bridges.

A double opener or a double closer can be realized by using two contact bridges with identical closing directions. Accordingly, a double opener and a double closer can be realized simultaneously by using two contact bridges per closing direction.

In the context of the present disclosure, the term closing direction is to be understood as referring to the direction of movement of the actuating plunger in each case with respect to a pair of fixed contacts, in which the plunger moves in such a way that an electrical contact of the respective pair of fixed contacts is established by the contact bridge.

The term contact point is to be understood in such a way that it does not only refer to point-like contacts, but also to linear or surface-like contacts. It is obvious to the expert that a purely point-like contact is not possible, but always covers at least a small area.

Preferably, the at least one contact bridge has at least two contact points at one end and at the other end for electrically contacting the first pair of fixed contacts in parallel, wherein each of the contact points is designed to completely switch a rated electrical power of the snap switch.

This design creates electrical and mechanical redundancy, so that even if up to two contact points fail, the snap switch is still available. The contact bridge can be connected to the switch by means of electrical and mechanical parallel electrical electrical conductors, whereby in this way, for example in the case of two parallel electrical conductors, the electrical or mechanical failure of one of the conductors, ie in this case of the two contact points assigned to this conductor, can be compensated.

In an advantageous embodiment, the snap switch has a housing, an actuating plunger having two switching positions with at least two contact bridges for electrically connecting at least a first pair of fixed contacts in the first switching position and at least a second pair of fixed contacts in the second switching position and with snap springs which are supported on an actuating element and the actuating plunger essentially symmetrically under prestress, the lines of action of which can be displaced by the actuating element in such a way that the switch plunger can be snapped from the first switching position, in which the actuating plunger is essentially in the rest position, to the second switching position, in which the actuating plunger is essentially in the actuating position, wherein the snap switch further has a positive opening arrangement by means of which a switchover from the first to the second switching position is forced when a positive opening force on the actuating element is exceeded, is characterized in that the at least two contact bridges have at one end and the other end at least two contact points for electrically parallel contacting of the first contact pair in the first Switching position and the second contact pair in the second switching position, wherein each of the contact points is designed to completely switch an electrical rated power of the snap switch, wherein the actuating plunger has a stop both in the closing direction of the first pair of fixed contacts and in the closing direction of the second pair of fixed contacts and a counter-stop which cooperates with the respective stop and limits a movement of the actuating plunger in the closing direction of the respective pair of fixed contacts.

A design of the contact bridges with at least two contact points each has the advantage that in this way an electrically parallel contact can be made between the fixed contacts. This means that the failure of one switching point per contact point can be compensated for per switching bridge, which means that one contact point can fail at both the one end of the contact bridge and the other end of the contact bridge, for example due to contamination, burnout or a mechanical defect, and the functionality of the snap switch is still maintained. This creates additional redundancy and increases switching reliability. The availability of the snap switch increases.

In a design with two contact points per bridge end, the following contacting options are possible when the parts of the contact bridge are cross-contacted, i.e. when the contact bridge is designed in such a way that all contact points are electrically connected to one another: Ideally, both contact points on both sides make contact. In the event of any kind of failure of one of the contact points either on the input side and/or on the output side, a situation is created in which at least one contact point is functional.

The term contact point is used here only to distinguish between the different positions of the contacts. Contact points are therefore not necessarily point-shaped, but can also be linear or flat.

The term contact pair is also used in the present application. Contact pairs are always the contact points of the associated fixed contacts arranged at opposite ends of a switching bridge. These comprise at least two contact points, i.e. a pair, but can also comprise several contact points. Preferably, however, the fixed contacts at both ends of the contact bridge comprise an identical number of contact points.

In an advantageous development of the snap switch, the contact bridges are each made in one piece. In this context, one piece means that the contact bridges are made entirely of the same material, which has both the energy transfer and the static load-bearing properties. In contrast to the state of the art, the contact bridges are characterized by a simple structure. The material of the contact bridges is therefore preferably designed to be both conductive and load-bearing.

A metal or metal alloy with spring properties is particularly suitable for the design of the contact bridge. Spring steel can be used, for example, although bronze, brass, nickel silver or copper alloys are preferred due to their higher conductivity. A copper-beryllium alloy is particularly preferred because it combines particularly good electrical and thermal conductivity and mechanical properties. Copper-nickel-silicon alloys can also be used due to the good electrical and thermal properties that can be achieved with these alloys. thermal conductivity in conjunction with good mechanical properties. This type of design ensures that the contact bridge is mechanically stable despite its small material cross-section and is sufficiently dimensioned for the currents to be switched.

The spring properties of the contact bridge can be selected and the contact bridge dimensioned in such a way that the movement of the actuating plunger is dampened even before the stop strikes the counter stop.

In a preferred embodiment, the contact bridges are designed in the form of a double H-bridge, each with an H-bridge with two bridge legs on either side of the actuating plunger and at least one transverse web.

The term H-bridge refers to the design of the contact bridge in the shape of an "H". This design provides two parallel contact paths for contacting the opposite fixed contacts, whereby at the same time a cross-contact can be made from one leg of the H-bridge to the other leg of the H-bridge via the crossbar.

The design as an H-bridge also offers the advantage that the individual legs of the H-bridge can be designed to be flexible in the closing direction, so that the height of the individual contact points at one end of the bridge can be adjusted. For example, the H-bridge can be used to compensate for a height difference due to a particle between the contact points at one end of the H-bridge.

The contact bridge can also be designed in such a way that on both sides of the actuating plunger one bridge leg is designed to lead and the other bridge leg to lag. With such a design, a contact bridge can be realized in which the contact point arranged on the leading bridge leg is mainly exposed to switching arcs and the associated burn-off.

In this context, leading means that the leading leg of the switching bridge, or the contact point arranged on the leading leg, comes into contact with the fixed contacts first in the closing direction of the contact bridge and establishes an electrically conductive connection. The lagging contact point only contacts the fixed contact when a conductive connection already exists via the leading leg.

Conversely, when opening, this means that the trailing leg of the contact bridge first separates the electrical connection and only then opens the leading leg. This ensures that a switching arc is only created at the leading contact point and only the leading contact point tends to weld to the fixed contact, since it switches higher currents than the trailing contact.

In a preferred embodiment, the material of the respective contact point can be adapted to this. In particular, the contact points on the leading legs can be designed to be more resistant to burn-off. Suitable materials for the contact points of the leading leg are, for example, silver, gold or silver or gold alloys.

Conversely, the trailing leg can have contact points made of a highly conductive but less resistant material, e.g. gold.

With mixed loads, the leading contact point switches the high currents and is loaded accordingly. The lagging contact point switches when the contact resistance of the leading contact point becomes too high at lower currents. The lagging contact can have a contact material that is more suitable for lower loads, since it does not switch high loads.

In a further embodiment, the contact bridges are designed to be spring-elastic. This allows manufacturing tolerances to be compensated and reliable contact to be achieved, for example by compensating the height of particles. Furthermore, a spring-elastic design of the contact bridges can support the opening of the snap switch. The metals and metal alloys already mentioned above are particularly suitable as materials for the design of the contact bridge. A spring-elastic design of the contact bridges also ensures reliable contact between the contact points and the fixed contacts. Preferably, the position of the switching positions of the actuating plunger is coordinated with the dimensions of the contact bridges so that the stop in the rest position of the actuating plunger is not in contact with the respective counter-stop. The contact bridge is dimensioned in terms of its geometric dimensions and spring constant so that in the rest position a force acting through the contact bridge against the closing direction is greater than a force acting through the snap springs in the closing direction.

The rest position of the actuating plunger refers to the static position of the actuating plunger in a switching position. This means the stable position that occurs when the switching process is complete and a balance of forces is established.

Reliable contacting can also be supported if the contact bridges are designed in such a way and the contact points are arranged in such a way, and relative to the fixed contacts, that the contacts are self-cleaning.

Self-cleaning of the contacts can be achieved, for example, by designing the contact points and the fixed contacts and arranging them relative to each other in such a way that a lateral movement is caused between the contact point and the fixed contact, at least when the contacts are closed.

Such a lateral movement removes and clears away deposits caused by burn-off, for example, during the lateral movement, thus always ensuring reliable contact.

If, for example, the contact bridge is made of a spring-elastic material, then if an electrical connection already exists, i.e. if the contact points are already in contact with the fixed contacts, a further movement of the contact bridge in the closing direction can cause a lateral movement of the contact points and the fixed contacts relative to each other, whereby deposits are rubbed off and simultaneously pushed away from the contacts.

In one embodiment, a reinforcement arrangement can be assigned to the at least one contact bridge in the opening direction. The reinforcement arrangement can ensure that the at least one contact bridge itself can be made weaker and still have sufficient stability. Such a reinforcement arrangement can be useful in the opening direction in particular, since welds caused by thermal stress may have to be removed in this direction. At the same time, if the reinforcement arrangement acts exclusively in the opening direction, it can ensure that there is flexibility in the closing direction on the one hand, and sufficient stability in the opening direction on the other.

Such a reinforcement arrangement can, for example, be arranged on the actuating plunger, in particular be formed integrally with the actuating plunger.

Alternatively, a multi-part design is also conceivable in which the reinforcement arrangement is designed as a separate component.

By arranging the reinforcement arrangement, and in particular by forming the reinforcement arrangement in one piece with the actuating plunger, a particularly space-saving and, in particular, easy-to-implement realization can be achieved.

The actuating plunger can, for example, be designed in such a way that the contact bridge is inserted as a component into a receptacle of the actuating plunger and is fixed in place by a second part of the actuating plunger.

The reinforcement arrangement can be designed, for example, as a molding extending from the actuating plunger in the direction of extension of the contact bridge. The moldings and the receptacle are preferably designed in such a way that the contact bridge is held prestressed against the closing direction when inserted into the actuating plunger. In a side view, the contact bridge is in contact with the actuating plunger and the moldings in the inserted state preferably at three points. A bearing with three supports achieves a statically determined situation and ensures that there is no static overdetermination of the bearing of the contact bridge. Furthermore, a defined prestress of the contact bridge can be achieved by three supports. The contact bridge preferably rests on the support arrangement on both sides of the actuating plunger and is prestressed within the actuating plunger by a third support. For this purpose, the supports formed by the support arrangement act on one side surface of the contact bridge and the support formed within the actuating plunger acts on an opposite side surface of the contact bridge.

Various advantages can be achieved by pre-tensioning the contact bridge. Manufacturing tolerances of the contact bridge can be compensated without the need for rework, as the contact bridge is brought into a defined position by the moldings. It is also possible for the contact bridge to have a defined pre-tension, meaning that an increased force is immediately available in the opening direction to open the contacts.

The moldings can be implemented particularly easily during the manufacture of the actuating plunger, e.g. in plastic injection molding, and can be produced in the necessary dimensions.

It is preferred if the supports formed by the moldings are designed symmetrically to the actuating plunger and support the contact bridge in the uncontacted state at a distance of at least 1/5, preferably at least 1/4, more preferably at least half, particularly preferably at least 3/4 of a projection of the contact bridge onto a line extending perpendicular to a longitudinal axis of the actuating plunger and parallel to a longitudinal extension of the contact bridge.

To determine the distance, the contact bridge is projected perpendicularly onto a line that is perpendicular to the longitudinal axis of the actuating plunger and runs parallel to a longitudinal extension of the contact bridge.

The further out on the contact bridge the support is, the shorter the portion of the contact bridge that projects beyond the support and can deform elastically when the contact is opened, and the greater the force that can be transmitted in the opening direction. It has proven to be sensible to arrange the supports in the opening direction in a range between 3/4 and 4/5 of a distance perpendicular to a longitudinal axis of the actuating plunger, whereby the distance is determined perpendicular to a longitudinal axis of the actuating plunger and the end of the contact bridge is assumed to be the point at which the contact bridge rests on the fixed contact when in contact. The supports are preferably designed as linear supports. The bearings are preferably floating bearings.

An opening force acting on the actuating plunger is thus transferred to the contact bridge closer to the contact points and at the same time the freely projecting length of the contact bridge is reduced. A force acting against the opening, e.g. by welding the contact point to the fixed contact, acts via a reduced lever arm, so that there is less risk of the contact bridge bending.

In order to prevent the contact bridge from slipping relative to the actuating plunger, it can be fixed in the holder by a fixed bearing. It has been found that fixing can be carried out particularly easily by moldings onto the contact bridge that engage in correspondingly designed recesses in the holder.

The contact bridge can be designed in particular as a stamped and bent part. Stamped and bent parts can be manufactured cost-effectively and in high quality.

Alternatively, other manufacturing methods can be used, especially for smaller quantities. For example, various cutting processes can be used, e.g. using a water jet or laser with a subsequent bending step.

In order to be able to reliably transmit a prescribed opening force for a forced opening of the rest position, the support arrangement is dimensioned such that an opening force of at least 10 N, preferably 20 N, more preferably 30 N can be transmitted to the contact points of the contact bridge. In this way, it can be ensured that the snap switches according to the present application also comply with the standard DIN EN 60947-5-1. However, the moldings also make it possible to transmit higher forced opening forces than the 20 N required by the standard, so that in particular a transmission of 30 N and more can be achieved.

The actuating plunger can, for example, be designed in at least two parts, such that the contact bridge can be inserted between two parts of the actuating plunger and thus fixed.

In an alternative design, the contact bridge is overmolded with the actuating plunger. This design has the advantage that it is particularly cost-effective to implement, reduces the number of components of the snap switch and it offers particularly good fastening of the contact bridge, since the contact bridge is fixed in the area of the actuating plunger in a form-fitting and force-fitting manner.

In one embodiment, a first distance between a contact point and an associated fixed contact is smaller than a second distance between the stop and the associated counter-stop. This means that the contact points and the fixed contacts already establish electrical contact during the closing process before the stop comes into contact with the counter-stop. The fact that the actuating plunger essentially breaks through during closing ensures that the contacts are self-cleaning, since the additional axial movement of the actuating plunger causes a lateral movement of the contact points of the contact bridge.

It has been shown that a difference between the first distance and the second distance, e.g. between 0.1 mm and 0.3 mm, achieves particularly good results in terms of the cleaning effect achieved and the reduction of the bounce of the contact points. Because the actuating plunger first penetrates and the counter-stop, the contact bridge can compensate for part of the distance covered during the rebound through its spring properties. This means that the bouncing processes are reduced not only by dissipating the kinetic energy, but also because the contact bridge compensates for part of the movement distance through elastic rebound during the counter-movement of the plunger.

By optimizing the design, the number of bounces can be drastically reduced and the service life of the snap switch can be maximized. In a preferred embodiment, the snap springs for actuating the actuating plunger, a spring force of the contact bridge and the differential distance are coordinated in such a way that the number of bounces is minimized, in particular to 1 or zero.

In the case of snap switches designed as switch switches, the number of bouncers can be reduced to 1 or 2 due to the stronger snap springs compared to other snap switches. A further reduction is currently not possible due to the significantly increased kinetic energy when switching the actuating plunger due to the stronger snap springs.

All contacts, both on the contact bridge and on the fixed contacts, can be cylindrical, flat or spherical/oval (contact rivet). With spherical contacts, the contact surface is point-shaped, with cylindrical contacts it is linear, and with two-surface contacts it is flat.

The formulation that two elements are assigned to one another is used in the present application for elements that interact with one another, in particular interact with one another electrically or mechanically. In this sense, two elements that establish an electrical connection through mechanical contact are assigned to one another. For example, these can be a contact point and a fixed contact that electrically contact one another in a switching position of the actuating plunger. In the same way, two mechanical elements that interact mechanically, e.g. meet one another or support one another, are assigned to one another. For example, these can be a stop and the counter-stop that is arranged in such a way that the stop hits when the actuating plunger switches from one switching position to the other switching position. Likewise, a reinforcement arrangement is assigned to the contact arm of the contact bridge, for which this reinforcement arrangement forms a support.

The self-cleaning of the switching points can be designed to be pushing or pulling. Depending on the angle at which the contact points and the fixed contacts meet, a pushing or pulling relative movement is carried out between the contacts. Further details can be found in the embodiments described below.

Advantageous embodiments and variants of the invention emerge from the subclaims and the following description. The features listed individually in the subclaims can be combined with each other in any technically reasonable manner and with the features explained in more detail in the following description and represent other advantageous embodiments of the invention.

• 1 ein erstes Ausführungsbeispiel eines Schnappschalters gemäß der vorliegenden Anmeldung in vereinfachter Darstellung,
• 2 eine Prinzipskizze des Betätigungsstößels mit der ersten Kontaktbrücke sowie zugeordneten Festkontakten,
• 3a) bis d) einen Schließvorgang einer Kontaktbrücke des Schnappschalters gemäß 2,
• 4a) bis c) einen Öffnungsvorgang der Kontaktbrücke aus 3,
• 5 ein Ausführungsbeispiel eines Betätigungsstößels, wie er in den 3 und 4 gezeigt ist, in Schnittdarstellung,
• 6 eine dritte Ausgestaltungsform einer Kontaktbrücke,
• 7 eine vierte Ausführungsform einer Kontaktbrücke,
• 8a) und 8b eine Kontaktbrücke mit einem vorauseilenden und einem nacheilenden Brückenschenkel und
• 9 einen Schnappschalter gemäß dem Stand der Technik (schon behandelt).

The present invention is explained in detail below using exemplary embodiments with reference to the attached figures. They show:

• 1 a first embodiment of a snap switch according to the present application in a simplified representation,
• 2 a schematic diagram of the actuating plunger with the first contact bridge and associated fixed contacts,
• 3a) to d) a closing operation of a contact bridge of the snap switch according to 2 ,
• 4a) to c) an opening process of the contact bridge 3 ,
• 5 an embodiment of an actuating plunger as shown in the 3 and 4 shown in section,
• 6 a third design form of a contact bridge,
• 7 a fourth embodiment of a contact bridge,
• 8a) and 8b a contact bridge with a leading and a trailing bridge leg and
• 9 a snap switch according to the state of the art (already discussed).

In the figures, unless otherwise stated, identical reference symbols designate identical or corresponding components with identical functions.

1 shows a first embodiment of a snap switch 100 according to the present application.

The snap switch 100 is simplified in the illustration shown and shown with the housing 1 open, so that the functionality of the components located in the snap switch 100 can be seen more clearly. The essential function of the snap switch 100 is accomplished by an actuating plunger 2 having at least two switching positions, wherein the actuating plunger 2 can be switched by means of an actuating element 3 between a first switching position, as shown in 1 is shown and can be switched to a second switching position in which the actuating plunger 2 is in a position displaced relative to the first switching position in the direction of the actuating element 3. The switching element 3 is connected to the actuating plunger 2 via two snap springs 8, 9 supported in parallel on the switching element 3 and the actuating plunger 2, so that by actuating the actuating element 3 the characteristics of the snap springs 8, 9 are displaced in such a way that the actuating plunger 2 is snapped from the first switching position to the second switching position. In the present embodiment, the actuating element 3 is further actuated by means of a compression spring 4, so that the 1 The first switching position shown is stabilized by the compression spring 4.

The in 1 The snap switch 100 shown further has a positive opening arrangement consisting of a first positive opening lever 5 and a second positive opening lever 6. The positive opening levers 5, 6 are supported at one end on a circumferential collar of the actuating plunger 2 and at the other end are slidably mounted in the housing 1 of the snap switch 100. If a predetermined actuating force is applied via the actuating element 3, this comes into contact with the positive opening levers 5, 6 and, by tilting the positive opening levers 5, 6, causes an indirect mechanical coupling of the actuating element 3 via the positive opening levers 5, 6 to the actuating plunger 2, so that, in the event that it was not possible to snap the actuating plunger 2 from the first switching position to the second switching position, a mechanically forced switchover takes place.

As already explained with reference to the prior art, such a positive opening may be necessary if, for example, due to thermal stress, contacts of the snap switch 100 are welded together in a switching position (in this case the first switching position) and as a result the snap springs 8, 9 are not able to release the contacts and switch the switching position.

In the present case 1 In the snap switch 100 shown, a first contact bridge 31 and a second contact bridge 32 are arranged on the actuating plunger 2, wherein in the 1 In the first switching position of the actuating plunger 2 shown, the first contact bridge 31 is not in contact with the fixed contacts 21, 22 assigned to it and the second contact bridge 32 electrically connects a third fixed contact 23 and a fourth fixed contact 24. To contact the respective fixed contacts 21, 22, 23, 24, the contact bridges 31, 32 have contact points 17, 18, 19, 20 arranged on the ends thereof, which reinforce the contact bridges 31, 32 and thus make them wear-resistant.

Reinforcing arms 25, 26 are arranged integrally as molded-on parts on the actuating plunger 2 to support the contact bridge 31, 32 in the opening direction. The reinforcing arms 25, 26 extend away from the actuating plunger 2 on both sides. On a side facing the contact bridge 31, 32, the reinforcing arms 25, 26 have a slope that is selected such that the contact bridge 31, 32 only rests against the reinforcing arms 25, 26 at the end. A side of the reinforcing arms 25, 26 facing away from the contact bridge 31, 32 is aligned perpendicular to a longitudinal axis and direction of movement of the actuating plunger 2 and in the present embodiment serves as a stop 41, 42 to limit a movement of the actuating plunger 2 in the closing direction.

By designing it as a stop 41, 42, a closing movement of the actuating plunger 2 is limited in the closing direction by striking a counter-stop 51, 52 formed in the housing 1. By striking the stop 41, 42 against the counter-stop 51, 52, part of the kinetic energy of the actuating plunger 2 is absorbed, thus reducing the bouncing of the actuating plunger 2 itself.

Out of 1 It is clear that a first distance s1 between the contact points 17, 18, 19, 20 on the contact bridge 31, 32 and the respectively associated fixed contacts 21, 22, 23, 24 is smaller than a second distance s2 between the stop 41, 42 and the respectively associated counter-stop 51, 52. This design has the consequence that an electrical contact is already established before the stop 41, 42 meets the counter-stop 51, 52. This ensures, on the one hand, that part of the kinetic energy is absorbed by the spring-loaded contact bridges 31, 32 before the stop 41, 42 hits the counter stop 51, 52 and, on the other hand, that the actuating plunger 2 moves even further after the contact points 17, 18, 19, 20 hit the fixed contacts 21, 22, 23, 24. moved in the closing direction, the contact points 17, 18, 19, 20 execute a lateral movement relative to the fixed contacts 21, 22, 23, 24, which causes a self-cleaning of the contact points.

The stop 41, 42 also reduces the mechanical load on the contact bridges 31, 32, since the kinetic energy of the actuating plunger 2 does not have to be absorbed exclusively by the contact bridges 31, 32, but is essentially dissipated by the impact of the stop 41, 42 on the counter stop 51, 52. This makes it possible to reduce the mechanical load on the contact bridge 31, 32 compared to the prior art as described in 9 shown, to be less massive so that the mass of the contact bridge 31, 32 can be reduced. Because the contact bridge 31, 32 has a lower mass, the bouncing is also reduced.

The fact that the contact bridge 31, 32 elastically compresses over the differential distance Δs between the first distance s1 and the second distance s2 after the electrical contact has been closed between the contact points 17, 18, 19, 20 and the associated fixed contacts 21, 22, 23, 24 until the stop 41, 42 hits the counter stop 51, 52 ensures that even if the actuating plunger 2 bounces back, the mechanical and electrical contact initially remains for the difference.

2 shows a schematic diagram of the actuating plunger 2 with the first contact bridge 31 and the fixed contacts 21, 22 assigned to it in the second switching position.

The statements made in the following figures with regard to the second pair of fixed contacts 21, 22 and the first contract bridge 31 as well as the associated first stop 41 and the first counter stop 51 are exemplary and apply mutatis mutandis also to the opposite direction of movement and the pair of fixed contacts 23, 24 provided for this purpose, the second contact bridge 32, as well as the second stop 42 and second counter stop 52 formed in this direction of movement.

The representation in 2 is greatly simplified and is essentially intended to explain the operating principle of the embodiments shown in more detail. The first contact bridge 31, now shown in detail, is held in a recess of the actuating plunger 2 on the actuating plunger 2. The first contact bridge 31 is designed in the embodiment shown as a so-called H-bridge, whereby the contact bridge 31 resembles the letter "H" in a plan view from above and has two parallel extending bridge legs 311, 312, which are connected by means of a 2 not visible crosspiece 313. Reinforced contact points 314, 315, 316, 317 are arranged at the ends of the bridge legs 311, 312, which reinforce the contact bridge 31 and thus make it wear-resistant. In the exemplary embodiment shown here, the contact points 314-317 are designed as reinforcing surfaces in the shape of a cylinder jacket and welded onto the ends of the bridge legs 311, 312. The cylindrical shape extending transversely to the direction of extension of the bridge legs 311, 312 creates a linear contact surface between the fixed contacts 21, 22, which are flat in the exemplary embodiment shown here, and the contact points 314-317, over which electrical current flows.

The contact bridge 31 is designed as a concavely curved leaf spring which is supported in the opening direction, ie when an electrical contact closed between the contact points 314-317 and the fixed contacts 21, 22 is opened again, by a reinforcing arrangement arranged on the actuating plunger 2 in the form of reinforcing arms 25, 26. In the present embodiment, the reinforcing arms 25, 26 are formed as integrally formed parts with the actuating plunger 2 and support the contact bridge 31 in the opening direction, as described below in connection with 3 will be explained in more detail.

In the present embodiment, the reinforcement arms 25, 26 are simultaneously designed as a first stop 41, with which the actuating plunger 2 strikes a first counter-stop 51 in the closing direction, which in this case is designed to be identical to the fixed contacts 21, 22. The design shown is particularly easy to manufacture, since an additional counter-stop 51 does not have to be designed separately. At the same time, however, the fixed contacts 21, 22 must be designed to be significantly more solid so that they can dissipate the transmitted kinetic energy.

3 shows in the 3a) to 3d ) an arrangement similar to the arrangement in 2 in a plan view from the front when closing the contact between the first contact bridge 31 and the first pair of fixed contacts 21, 22. The arrangement shown differs from the design of the 2 in that the first counter-stop 51 is formed separately from the fixed contacts 21, 22.

In 3a) It is shown how the actuating plunger 2 moves from the first switching position, in which - as in 1 shown - the second contact bridge 32 contacts the fixed contacts 23, 24 in the second switching position, in which a contact between the first contact bridge 31 and the fixed contacts 21, 22 The direction of movement of the actuating plunger 2 is determined by the 3a) indicated by the arrow drawn in. In the first partial figure, it can be clearly seen that the bridge legs 311, 312 extending on both sides of the actuating plunger 2 - in the present illustration, this is the bridge leg 312 pointing forwards - rest on the reinforcement arrangement in the form of the reinforcement arms 25, 26. The first contact bridge 31 is shaped in such a way that the bridge legs 311, 312 only rest on the end of the reinforcement arms 25, 26. Because the first contact bridge 31 is designed in such a way that it is only clamped in the middle and rests on the end of the reinforcement arms 25, 26, a statically determined design with a defined prestress of the first contact bridge 31 is created.

3b) shows the point in time at which the contact points 315-317 of the first contact bridge 31 come into contact with the fixed contacts 21, 22. In principle, a movement of the actuating plunger 2 could stop at this point in time, since at this point in time there is contact between the second pair of fixed contacts 21, 22 and the contact points 314-317 and thus an electrically conductive path is established between the first fixed contact 21 and the second fixed contact 22. In order to further increase the reliability of the snap switch according to the present application, the contact points formed by the contact points 314-317 and fixed contacts 21, 22 are designed to be self-cleaning, which means that particles, deposits or deposits caused by the burning of the materials on the fixed contacts 21, 22 or the contact points 314-317 are mechanically loosened and pushed away. In the present embodiment, this is done by the actuating plunger 2 starting from the 3b) shown situation, in which there is already contact between the contact points 314-317 and the fixed contacts 21, 22, is moved further in the direction shown, whereby the spring-elastic contact bridge 31 is slightly bent, which results in a lateral movement between the fixed contacts 21, 22 and the contact points 314-317. This lateral movement guides the contact points 314-317 along the fixed contacts 21, 22, so that the friction generated at the contact points loosens deposits and particles and pushes them outwards. In this way, a permanently low contact resistance between the contact points 314-317 and the fixed contacts 21, 22 is ensured, thus increasing the reliability of the snap switch 100.

In addition, the contact bridges 31, 32 formed with individual bridge legs 311, 312 ensure that in the event of deposits and particles on one of the contact partners, height compensation can take place due to the spring-elastic design of the contact bridge - also between the individual legs 311, 312 for contacting a fixed contact 21, 22 - whereby an electrical contact is closed even more reliably.

In 3D ) the end of the movement of the actuating plunger 2 is indicated; in the position shown, the actuating plunger 2 has moved into a stable position after reaching the first counter-stop 51 due to the rebound from the first counter-stop 51 and due to the spring force of the first contact bridge 31, which will only be left again by switching.

The 4a) to c) show an opening process of the first contact bridge 31 from 3 .

4a) shows the 3D ) situation reached after complete closure of the first contact bridge 31 from 3 . As shown by the 4a) to c), the actuating plunger 2 now moves downwards, ie away from the fixed contacts 21, 22, so that an electrical connection between the fixed contacts 21, 22 and the contact points 314-317 of the contact bridge 31 is released again. It is assumed here that the contact points 314-317 are welded to the fixed contacts 21, 22 due to thermal stress from the flowing currents and therefore adhere to them and do not come loose immediately when the contact bridge 31 comes into contact with the reinforcing arms 25, 26.

4b) shows the position of the actuating plunger 2 in which the bridge legs 311, 312 of the contact bridge 31 are in contact with the reinforcing arms 25, 26 of the actuating plunger 2 and then the contact points 314-317 are released from the fixed contacts 21, 22 by a further movement of the actuating plunger 2 in the direction away from the fixed contacts 21, 22. By the further movement of the actuating plunger 2, the force in the direction of movement is introduced into the contact bridge 31 via the reinforcing arms 25, 26. The reinforcing arms 25, 26 additionally reinforce and stiffen the contact bridge 31 in this direction. In this way, it is possible, as in 4c ) has shown that, contrary to the spring-elastic design of the contact bridge 31, an increased opening force can be applied to the welded contact point so that it is opened reliably.

In this embodiment, the contact points 314-317 are subtracted from the fixed contacts 21, 22, ie a tensile force acts in the contact bridge 31.

5 shows an alternative design of the actuating plunger 2 in a longitudinal section.

In the 5 As shown, the prestressing of the first contact bridge 31 is implemented by means of three supports 61, 62, 63. On the one hand, the first contact bridge 31 rests on the reinforcing arms 25, 26 extending on both sides of the actuating plunger 2, which form a first support 61 and a second support 62. The first support 61 and the second support 62 act on a surface of the first contact bridge 31 facing the reinforcing arms 25, 26 and located at the front in the closing direction. On the other hand, the first contact bridge 31 rests centrally on a third support 63, which acts on an opposite side of the first contact bridge 31 and places the concavely curved first contact bridge 31 under prestress. In order to achieve a defined pre-tensioning and prestressing of the first contact bridge 31, an abutment is arranged opposite the third support 63 so that the first contact bridge 31 is clamped in the position shown between the third support 63 and the abutment. The abutment ensures that the contact bridge 31 has a defined pre-tensioning in the desired position.

The second contact bridge 32 is arranged mirrored to the first contact bridge 31 on a mirror plane that is perpendicular to a direction of movement of the actuating plunger 2 and runs centrally through the actuating plunger 2, and is also held and prestressed.

At the contact bridges 31, 32 of the 5 In the embodiment shown, contact rivets are arranged at the ends, which serve to reinforce the contact points 17, 18, 19, 20 and make them more resistant to burn-off and mechanical stress.

6 shows in a more detailed representation a further embodiment of the contact bridge 31, as it is arranged in an arrangement as shown in the 1 to 5 can be used.

The in 6 The contact bridge 31 shown is designed as an H-bridge with a first bridge leg 311 and a second bridge leg 312. The bridge legs 311, 312 are connected to one another centrally by the crosspiece 313 and are each divided into two bridge leg sections 311a, 311b, 312a, 312b extending from the crosspiece 313.

In the present embodiment, the crosspiece 313 is arranged centrally, so that the bridge leg sections 311a, 311b, 312a, 312b each extend symmetrically from the crosspiece 313 and at right angles to it. The bridge legs 311, 312 are initially designed to run with a positive curvature and then extend with a negative curvature, so that the contact bridge 31 is concave in a central area and convex in the end areas of the bridge legs 311, 312. The contact points 314-317 are arranged at the end of the bridge legs 311, 312, and in the present embodiment, these are designed as contact rivets. Contact rivets have the advantage over soldered contacts that they can be produced using other manufacturing processes. This means that other material combinations are possible. As the name “contact rivets” already suggests, the contact points 314-317 are attached to the respective bridge leg end with a rivet or are themselves designed as a rivet.

In the present embodiment, the crosspiece 313 is designed such that it extends linearly between the bridge legs 311, 312 with a semicircular formation on both sides of the bridge legs 311, 312. This formation can be used to align and center the contact bridge 31 within the actuating plunger 2 and thus represents an assembly aid.

7 shows a further embodiment of a contact bridge 31, wherein the 7 The contact bridge 31 shown has a completely convex shape.

The 8a) and 8b) show a modified embodiment of the contact bridge 31 from 6 .

In contrast to the 6 shown embodiment of the first contact bridge 31, in which both bridge legs 311, 312 are designed to run parallel, the embodiment of the first contact bridge 31 according to 8a) designed such that one bridge leg 311 is designed to lead and the other bridge leg 312 is designed to lag.

Leading in this context means that the contact point 314, 316 arranged on the leading bridge leg 311 contacts the associated fixed contact before the contact point 315, 317 arranged on the trailing bridge leg during a movement in the closing direction and thus establishes an electrically conductive connection before this. Conversely, the trailing bridge leg 312 or the contact points 315, 317 assigned to it are first lifted off from the respective fixed contact when the switching position is opened and the bridge leg 311 leading in the closing direction is the second to release the connection.

In the 8 In the embodiment shown, the first bridge leg 311 and thus also the contact points 314, 316 assigned to it are designed to lead and the second bridge leg 312 with the assigned contact points 315, 317 to lag in the closing direction. 8a) shows the entire contact bridge. This design means that when the contacts are opened, increased current densities and the associated arcing and the resulting burn-off essentially affect the contact points 314, 316 of the leading, first bridge leg 311. By selecting a suitable material, the leading bridge leg 311 can thus be equipped with contact points made of a material that is more resistant to burn-off, for example, whereas the lagging bridge leg 312 can be provided with contact points 315, 317 made of a very good conductor, but with arcing and significantly more burn-off and thus a more sensitive material.

8b) shows a detail enlargement from 8a) , from which it is particularly clear how a leading and a trailing bridge leg 311 can be realized. In the present embodiment, the bridge legs 311, 312 are bent in such a way that the first bridge leg section 311b shown here as an example projects beyond the second bridge leg section 312b in the closing direction by a height Δh and is thus leading in the closing direction.

In an alternative embodiment, the contact rivets used in each case could also have a different height, so that the bridge legs 311, 312 are bent in the same way, but the contact rivets used in each case of the leading contact point 314, 316 have a greater height than the contact rivets of the trailing contact point 315, 317. Such an embodiment can provide a greater material thickness for the leading contact point 314, 316, so that in addition to a material that is more resistant to burn-off, it also has an additional material thickness that can be worn away.

list of reference symbols

1

Housing

2

actuating plunger

3

actuator

4

compression spring

5

first positive opening lever

6

second positive opening lever

8

first snap spring

9

second snap spring

11, 12

receiving notch

13, 14

spacer

15

upper contact arm

16

lower contact arm

17

first point of contact

18

second contact point

19

third contact point

20

fourth contact point

21

first solid contact

22

second fixed contact

23

third fixed contact

24

fourth fixed contact

25, 26

reinforcement arm

31

first contact bridge

32

second contact bridge

41

first attack

42

second attack

51

first counterattack

52

second counterattack

61

first support

62

second support

63

third edition

100

snap switch

311

first bridge leg

311a, 311b

bridge leg sections

312

second bridge leg

312a, 312b

bridge leg sections

313

crossbar

314-317

contact points

324-327

contact points

Δh

Height

s1

first distance

s2

second distance

Δs

differential distance

Claims (13)

Snap switch (100) with a housing (1), an actuating plunger (2) having two switching positions with at least one contact bridge (31, 32) with contact points (314-317) arranged at one end and the other end on the contact bridge (31, 32) for electrically connecting at least a first pair of fixed contacts (21, 22) in a switching position and with snap springs (8, 9) which are supported on an actuating element (3) and the actuating plunger (2) essentially symmetrically under prestress, the lines of action of which can be displaced by the actuating element (3) in such a way that the actuating plunger (2) can be snapped over from a first switching position in which the actuating plunger (2) is essentially in the rest position to a second switching position in which the actuating plunger (2) is essentially in the actuating position, wherein the snap switch (100) further comprises a positive opening arrangement (5, 6), by means of which a switchover at least from the first to the second switching position is forced when a positive opening force on the actuating element (3) is exceeded, characterized in that the actuating plunger (2) has at least one first stop (41) in the closing direction of the first pair of fixed contacts (21, 22), which in cooperation with a first counter stop (51) limits a movement of the actuating plunger (2) in the closing direction of the first pair of fixed contacts (21, 22), wherein the snap switch (100) has two contact bridges (31, 32) for electrically connecting at least the first pair of fixed contacts (21, 22) and at least one second pair of fixed contacts (23, 24), wherein in the first switching position the first pair of fixed contacts (21, 22) and in the second switching position the second pair of fixed contacts (23, 24) are connected and wherein the actuating plunger (2) in the closing direction of the second pair of Fixed contacts (23, 24) has a second stop (42) which, in cooperation with a second counter-stop (52), limits a movement of the actuating plunger (2) in the closing direction of the second pair of fixed contacts (23, 24). Snap switch (100) according to patent claim 1 , characterized in that the contact bridges (31, 32) are designed to be spring-elastic. Snap switch (100) according to one of the preceding claims, characterized in that the contact bridges (31, 32) are designed in such a way and the contact points (17, 18, 19, 20) are arranged in such a way and relative to the fixed contacts (21, 22, 23, 24) that the contacts are self-cleaning. Snap switch (100) according to patent claim 3 , characterized in that the contact points (17, 18, 19, 20) and the fixed contacts (21, 22, 23, 24) are designed and arranged relative to one another in such a way that at least when the contacts are closed, a lateral movement is brought about between the contact point (17, 18, 19, 20) and the fixed contact (21, 22, 23, 24). Snap switch (100) according to one of the preceding claims, characterized in that a reinforcement arrangement (25, 26) is assigned to at least one of the contact bridges (31, 32) at least in the opening direction. Snap switch (100) according to patent claim 5 , characterized in that the reinforcement arrangement (25, 26) is arranged on the actuating plunger (2). Snap switch (100) according to patent claim 6 , characterized in that the reinforcement arrangement (25, 26) is formed integrally with the actuating plunger (2). Snap switch (100) according to one of the patent claims 6 or 7 , characterized in that the reinforcing arrangement (25, 26) is designed as a molded-on portion extending from the actuating plunger (2) in the direction of an extension direction of the contact bridge (31, 32), in particular in the form of reinforcing arms (25, 26). Snap switch (100) according to claim 8 , characterized in that the contact bridge (31, 32) is arranged in a receptacle of the actuating plunger (2) and the formations are designed such that the contact bridge (31, 32) is held in a prestressed manner. Snap switch (100) according to claim 8 or 9 , characterized in that the molded-on portions each form a support (61, 62) which supports the contact bridge (31, 32), at least in the contacted state, at a distance of at least 1/5, preferably at least 1/4, more preferably at least half, particularly preferably between 3/4 and 4/5 of a projection of the contact bridge (31, 32) onto a line extending perpendicular to a longitudinal axis of the actuating plunger (2) and parallel to a longitudinal extension of the contact bridge (31, 32). Snap switch (100) according to one of the Claims 6 until 10 , characterized by , that the reinforcement arrangement (25, 26) is dimensioned such that an opening force of at least 10 N, preferably at least 20 N, more preferably at least 30 N can be transferred to the contact points of the contact bridge. Snap switch according to one of the preceding claims, characterized in that in the rest position of the actuating plunger (2) a first distance (s1) between a contact point (17, 18, 19, 20) and an associated fixed contact (21, 22, 23, 24) is smaller than a second distance (s2) between the stop (41, 42) and the associated counter-stop (51, 52). Snap switch according to claim 12 characterized in that a difference distance (Δs) between the first distance (s1) and the second distance (s2) is between 0.1 mm and 0.3 mm.

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