DE2421941A1 - SNAP DEVICE, IN PARTICULAR SNAP SWITCHES - Google Patents

Description

DR.-INQ. DIPL-INe-M-SC. DIPL.-PHY9. "5R. OIPL.-PHV *. HÖGER - LEGAL RIGHTS - GRIESSBACH - HAECKER A 40 667 b PATENTANWÄLTE .N STUTTGART

B / K Patent Development,

INC.

Boston, Massachusetts, USA

SNAP DEVICE, IN PARTICULAR SNAP SWITCHES

The invention relates to a snap device _/ in particular a snap switch with a pretensioned snap element made of a resilient flat material with outer legs arranged at a distance from one another, with a middle leg arrangement which is connected to one end of the outer legs via curved pieces at one end of the Schfiappelements with one end of the outer legs Element via which the other ends of the outer legs are held with respect to the ^ ittelschenkelanordnung in such a position that there is a bias of the snap element, with approximately in the middle of the snap element effective fastening devices for attaching the snap element to a bracket, with at least one actuating element for Tilting of the snap element from a first to a second stable position and with at least one stop connected to the holder with which the snap element interacts.

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U.S. Patent 3,213,228 describes a snap element made of a resilient flat material, which has two flat, im has essential U-shaped loops, the side to freite are arranged. In the known snap element are the outer legs of the two loops are longer than the inner legs, and the ends of the outer legs are over a cross piece connected to each other. In the loops or in the snap element, a bias is generated by the ground the inner thighs spread apart. Because of this bias, the snap element can only do one of two take stable positions while it is unstable between these two positions. The pretensioned snap element snaps under the influence of a corresponding externally applied force from one of its stable positions to the other stable laae.

US Pat. No. 3,213,228 also describes a snap switch the one using the described snap element is constructed. With this snap-action switch, contacts on opposite sides of the snap-action device are aligned or arranged coaxially to one another. The known snap-action switch can thus be used as a single-pole, single-arm changeover switch or as be designed single-pole, two-armed changeover switch.

The well-known Schnanpschaltar possesses with regard to his Actuation occurring movement sequence, in terms of the force difference between the force to actuate and the Power to release, as well as very desirable properties in terms of its snap-on properties. Nevertheless, the well-known Snap switches do not fully satisfy in all cases. This also applies to other known snap-action switches, as shown in U.S. Patents 2,777,032 and 2,179,099.

The well-known snap switches can be relatively slow

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moving controls are operated. The contact pressure between contacts closed at the start of actuation takes on under some operating conditions the way that it gradually approaches the value "zero" or reaches this sonar, for a time which is sufficient, to allow a contact break to occur which may cause the contacts to stick together.

The invention is based on this prior art the underlying task ^ to propose an improved snap switch when it is actuated between previously closed contacts until the snap element tips over and becomes quick When these contacts open, a comparatively high contact pressure is maintained. It is also an object of the invention to design the snap switch so that the at contacts to be closed do not bounce or bounce only slightly when actuated.>

This object is achieved by a snap device, in particular by a snap switch of the type described at the outset, which is characterized according to the invention in that a first connection is provided which cooperates with a first point on one side of the snap element when this is in its first stable position is that a second stop is provided which cooperates with a second point on the opposite side of the snap element when this is in its second stable position that the first point is in a first area of the snap element, v / which is is located at the end of the same facing away from the curved pieces and which is limited by the "i.ttellini _e " of the latter running in the longitudinal direction of the snap element on the one hand and by a cross line running transversely thereto and through the fastening devices on the other hand, and that the second point

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lies in a second area at the same end of the snap element, which is also from the center line and the transverse line which is on the other side of the center line.

It is an advantage of the snap switch according to the invention that no contact bounce or only very little contact bounce occurs. But this is very important because of contact bounce often to scorching of the contacts and other undesirable effects, for example in the connected ones Circuits leads. With the snap switch according to the invention, contact bouncing is simple and economical Way by several orders of magnitude, both in terms of strength and in terms of Duration. In addition, with the snap switch according to the invention, up to the point in time at which a rapid separation closed contacts, an exceptionally high contact pressure is maintained. It is also an advantage of the snap switch according to the invention that only a relatively small stroke is required for the actuating element. moreover, this results when previously closed contacts are opened very quickly a relatively wide gap between the contacts, as will be explained in more detail below target.

In summary, it can be stated that the snap switch according to the invention for a given size is a comparatively shows great breaking power, and that, moreover, poor contacting under all operating conditions and contact bounce can at least largely be avoided. In addition, for the actuating element of the Snap switch only requires a relatively small working stroke.

The switch according to the invention has closed when opening

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There is a minimal loss of contact pressure between contacts on. Furthermore, when the closed contacts are opened, a greater distance is achieved between them, than with previously known snap switches of the same size. Furthermore, the distance between the contacts is at the end of the Opening process both with dynamic observation and with static observation larger than with the previously known Snap switches, in particular for a predetermined working stroke of the actuating element to bring about the Contact opening.

Another advantage of the snap switch according to the invention is that it is excellent for miniaturization suitable because it has a high interruption capacity even in small format and has excellent electrical properties. Moreover, the snap switch is according to the invention Its structure is simple and easy to adjust and, moreover, has a long service life.

Details and advantages of the invention are given below explained in more detail with reference to a drawing and / or are the subject of the claims for protection. In the drawing show:

Fig. 1 is a plan view of a snap element for a first Embodiment of a snap device according to the invention and on an enlarged scale;

Fig. 2 is a partially schematic, perspective illustration a first Ausunasform a Snap device according to the invention;

Fig. 3 is a side view of the snap device according to Fig. 2;

4 shows a schematic perspective illustration

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a second embodiment of a snap device according to the invention;

FIG. 5 shows a side view of the snap device according to FIG. 4;

6 shows an end view of the snap device according to FIGS. 4 and 5;

7 shows a schematic perspective illustration of a third embodiment of a snap device according to the invention;

8 shows a side view of the snap device according to FIG. 7;

Figure 9 is an end view of the snap device of Figure 7;

Fig. 10, 11

and 12. a side view, a plan view and a cross-section an embodiment of a fastener for snap devices according to the invention;

13 is a side view of a fourth embodiment a snap device with a fastening element according to FIGS. 10-12;

FIG. 14 shows a plan view of the snap device according to FIG Fig. 13;

15 shows a front view of the snap device according to FIGS. 13 and 14;

16 shows a schematic end view of the snap element

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for snap devices according to the invention with electrical contacts, as in all embodiments of snap devices according to the invention can be provided;

17 shows an enlarged plan view of the snap element of a fifth embodiment of a snap device according to the invention;

18 shows a schematic, perspective illustration of a fifth embodiment of a snap device according to the invention with a snap element according to FIG. 17;

19 shows a side view of the snap device according to FIG. 18, seen in the direction of arrow 19 in this FIG.

20 shows an enlarged plan view of a snap element for a sixth embodiment of a snap device according to the invention, in the non-pretensioned state;

FIG. 21 shows an enlarged plan view corresponding to FIG. 20 of a snap element in the pretensioned state; FIG.

22 shows a schematic, perspective illustration of a sixth embodiment of a snap device according to the invention with a snap element according to FIGS. 20 and 21 and

23 shows an end view of the snap device according to FIG. 22 seen in the direction of arrow 23 in this figure.

Before going into more detail on the individual figures in the drawing

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It should be stated in advance that parts corresponding to the drawing are provided with the same reference numerals in the individual figures. It should also be noted that in the drawing, the dimensions of individual parts to illustrate and improve understanding of the invention have been modified and / or exaggerated. The drawings are therefore not necessarily true to scale.

Figures 1 to 3 of the drawing serve to explain a first embodiment of a snap switch according to the invention. The representations are rather schematic in that, instead of the electrical contacts actually used, stops are shown schematically, one or both of which can be electrical contacts such as those shown in FIG. 16, for example. One or more electrical contacts can be stationary, while others can be attached to the snap element to suitably cooperate with the stationary contacts. Details of the mounting plate or the like for the various actuating elements and for the arm to which the snap element is attached have been omitted for the sake of clarity, and the guide means for the actuating element (in the present case a pushbutton) for actuating the snap switch have also been omitted. The omitted details can be found, for example, in US Pat. No. 3,213,228, the teachings of which are included in the subject matter of the present application in this respect; moreover, the omitted details can easily be supplemented in a suitable manner by the person skilled in the art.

In detail, Fig. 1 shows a plan view of a snap element 2, as it is in various embodiments of Snap switches according to the invention is used. Such a snap element is otherwise in the US patent

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3,213,228. The snap element 2 is a sheet metal part 4 with two essentially U-shaped loops, which preferably made of spring steel sheet, and the outer legs of which are connected to one another by a resilient connecting piece 10 are. The shorter inner legs 12 and 14 of the loops have a small distance from each other, like the Drawing shows. Each of the inner legs is with one Verseh.en groove or a semicircular recess 16, wherein the two recesses are opposite to each other and in addition serve to facilitate the assembly and pretensioning of the snap element with the aid of the inner legs 12, 14. the inner and outer legs are made by semicircular arch pieces 18, 20 connected to one another.

In operation, the inner legs 12, 14 are spread further apart in accordance with the teaching of the aforementioned US patent than in the unloaded state, so that the entire snap element 2 is under a bias and under Action of a force at a suitable point in one or other of its stable positions snaps. When the ends of the outer legs of the U-shaped loops through a connector 10 are connected, a pretensioning force can be applied in the plane of the snap element with the aid of a single pretensioning device are generated, which lies between the inner legs 12, 14, as will be described below will. The snap element has a longitudinal center line and a transverse line, which goes through the attachment point.

In the case of the switch according to FIGS. 2 and 3, the snap element is 2 supported at the ends of the inner legs 12 and 14 by a single fastener 22 which is inserted into the through the Recesses 16 formed "opening" engages. The diameter of the bolt-shaped fastening element 22 is in the range the "opening" by a predetermined amount greater than that

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Diameter of the "opening" limited by the recesses 16, so that the inner legs 12 and 14 are pushed apart.

Figures 10 to 12 show a bolt-free fastening element 22, which is particularly suitable. The fastening element shown there provides the pivot points in a simple manner, which are desired in order to achieve adequate freedom of movement of the inner thighs, and thus the desired ones Bending and snap options for the entire snap element. The fastening element 22 consists of a base material with a square cross-section, which can be processed on a lathe, for example. If a suitable Turning tool is used, a shaft 24 is turned on the round material at the same time and provided with a thread. As the turning process progresses, a smooth cylindrical bolt surface can also be created with a suitable tool Achieve 26, wherein the rotary tool can in particular be designed so that its end at a suitable angle protrudes inward to create a concave surface 23. As a base material with a square cross-section is used is, the production of the concave surface 28 has the consequence that four pivot points or support points 30 result. Such a fastening element can be produced in a simple manner on automatic machines for the production of screws.

When using a fastening element 22, as shown in FIGS. 10 to 12, two of the bearing points are supported 30, »■ / oak diametrically opposite one another Parts of the inner legs 12 and 14 and the other two bearing points 30 are located in the gap between the inner ones Thighs (compare Fig. 14). The snap-on element 4 is simple with the aid of such a fastening element 22 and can be produced cheaply, fastened in such a way that it

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Has sufficient freedom to move in the area of the two bearing points 30 to bend.

The fastening element 22 .bzw. its shaft 24 is "Opening" formed through the recesses 16 passed and then through a washer 34 and finally through a suitable opening in a spring arm 36, which in turn is attached to a support arm. Finally the fastener 22 secured to the spring arm 36 with the aid of a locking nut 38.

It can be seen that to reduce the size of the switch the spring arm 36 runs transversely to the longitudinal direction of the snap element 2. For reasons not currently available to the applicant are known, the operating behavior is somewhat better than with the second, exemplary embodiment, which will be described further below.

The spring arm 36 is made of a spring material such as phosphor bronze or annealed beryllium copper, being phosphor bronze for both economic reasons and because of Their higher electrical resistance is preferred, since current flows into the snap element 2 via the spring arm 36. The spring arm 36 is in its front part with vertical Side walls 38 provided to give it the required strength. The rear end of the spring arm is in use conventional devices attached to a block 40 at a suitable height above a base plate (not shown). As mentioned, the attachment of the spring arm 36 to the block and the attachment of the block 40 to the Base plate using conventional devices, with devices being provided at the same time, in an electrical one Establish connection.

In the upper part of the switch housing is an actuating element

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42 slidably guided. The actuator 42 has in the embodiment, the shape of a cylindrical push button, the end of which in the vicinity of the block 40 on the spring arm 36 acts.

In the vertical direction above and below the connecting piece 10 of the snap element 2, stops 44 and 46 are arranged in only schematically indicated parts of the base plate or the switch housing. For the sake of simplicity, the stops are shown as cylindrical elements, the ends 45 and 47 of which are located in the vicinity of the snap-on element 2. In practice, the stops are in most cases electrical contacts. A corresponding construction is shown, for example, in FIG. 16, where electrical contacts 48 and 50 are attached to the stops 44 and 46, contacts 52 and 54 interacting therewith being provided on the snap element 2 at the same time. Such a construction (but not the spatial position of the individual elements) is common for fixed contacts are therefore not discussed further herein to details Soli _x with the exception that are formed, the support elements for the contacts 48 and 50 with respect to the snap-in element 2 is preferably adjustable . The electrical contacts 52 and 54 cooperating with the stationary contacts are anaebrächt in the end region of the snap-on element 2, specifically at points 56 and 58 in such a way that the movable contacts are arranged coaxially with the stationary contacts 48 and 50.

The terminals 44 and 46 or the stationary electrical contacts - if such are used - are set so that their ends 45 and 47 each lie in a plane which runs perpendicular to the direction of the snap movement of the connector 10, the planes below level ¹ ? or the height of the middle or inner legs 12, 14 ran, as is clear from the drawing. Since the snap

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element is shaped by the fastener 22 so that the outer legs 6, 8 are bent downwards brought the connector 10 in such a position that the point 56 of the snap element 2 in contact with the end 45 of the stop 44 is brought. '(Of course, if electrical contacts the position of the snap element 2 that shown in Fig. 16, wherein the contacts 48 and 52 one another touch.) The end 47 of the stop 46 remains without contact with the .Schnappelement 2 (the ^ corresponding would also contacts 50 and 54 do not touch each other). It should also be noted that the end of the stop 46 below the level of the inner legs 12, 14 of the snap element 2 is.

It is essential that the contact pairs of the switch not are coaxially arranged, i.e. the contacts 48,52 are not arranged coaxially with the contacts 50,54. Corresponding Points 44, 56 must not be arranged coaxially to points 46, 58 either.

The electrical current is fed to the switch via the spring arm 36 and from there passes via the inner legs 12, 14, the outer legs 6, 8 and the connecting piece to the electrical contacts 48 and 52. The switch is therefore a single-pole, single-armed switch. If two The snap-on element is used if the contacts are used as a common connection of a single-pole two-armed switch. The circuits are not shown in the drawing, since they are common.

If the actuating element 42 is moved downwards in order to press the inner ends of the inner legs 12, 14 downwards _/ as shown in FIG. 3, then this has the consequence that the snap element 2 is biased even further until the inner legs are closed the point of instability of the Schnaopele

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get into the so-called neutral or "Rchnapp" -plane whereupon the connecting piece 10 of the snap element 2 snaps upwards _/ (based on the drawing,) whereby the point 58 comes into contact with the pointed end of the stop 46 or electrical contact 54 coming into contact with electrical contact 50. At the same time, the snap element 2 moves out of contact with the pointed end 45 of the stop 44 or the contact 52 lifts off the contact 48.

At this point we want to point out two important characteristics of the mode of operation of the snap element:

When the snap element snaps over, there is no obstacle to the upward movement of point 56, with the exception of the natural spring action or damping effect of the snap element itself. As a result, point 56 of the snap element reaches a distance from stop 44 which is greater than the distance that is present when the snap element 2 has stabilized in its second stable position. This overshoot or this additional movement is referred to below as the dynamic movement of the snap element, and the largest resulting distance as the dynamic gap. After the snap element has overshooted, the latter comes to rest (as long as the actuating element is held in its lower position) in a stable position in which the point 56 of the snap element 2 is a predetermined distance from the stop 44, which is less than the width The distance at rest is called the static contact gap.

Also, what is very important, one can observe that during the downward movement of the actuator 42 to Causing a snap movement of the snap element 2 of the

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Gradually point 58 on the other side of the snap element is moved in the direction of the stop 46. Thus, when contacts are used, contact 54 becomes gradual and continuous moved towards contact 50. However, point 58 does not come into contact with the end of the stop 46 (or the electrical contact 54 does not come into contact with the contact 50) before the snap-on element 2 does not is snapped over and before the mechanical contact between the stop 44 and the point 56 of the snap element 2 is interrupted. The electrical contacts 50 and 54 therefore do not close before the contacts 48 and 52 are open. From it it follows that before every Schnnaopvorganq that leads to a Contact between the contacts 50 and 54 leads to the snap element 2 moving only a little bit during the snap action must move to bring the contacts 50 and 54 into contact with each other. From this it follows in turn that between The components or contacts only have a low speed and so only a low moment of inertia is built up can, and a switch according to the invention does in fact show practically no contact bounce. In reality it is in the contact bounce is present in most cases. The duration of the contact bounce is, however, four orders of magnitude shorter than with conventional snap switches.

This result is surprising for snap switches and the applicant has no explanation for this at the moment Phenomenon, with the exception that it could be based on the possibility of the snap element being used in the manner described above Way to twist and bend around an axis parallel to its center line and up or down to snap when it is properly placed and loaded in a switch. In an inventive Switch, the snap element is able to almost close open contacts before a snap action. This is in Important in view of the fact that the burning of the

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with snap switches mainly during contact bouncing of the moving contact takes place in relation to a fixed contact during the closing movement. But if only one Very little contact bounce occurs, the risk of burning the contacts is greatly reduced.

With regard to the ability of the snap element 2 _/ to twist around its longitudinal axis or its central axis, it should be noted that this possibility is greatly facilitated by the fact that the connecting piece 10 has the points 56, 58 in its end regions, which are connected to the stops 44, 46 cooperate, is flexible. This flexibility makes it essential that the two outer arms 6, 3 twist along their longitudinal axes. The connecting piece 10 can therefore be viewed as a laterally protruding spring arm, at the ends of which the switching contacts are attached. This spring arm can be moved onto and away from the stationary contacts, specifically through the legs 6, 8, 12 and 14, while at the same time it can be bent about the longitudinal axis.

When the snap element is in the position in which the contacts 50, 54 are closed, the inner legs 12, 14 can move upwards when the actuator 42 is released. The upward movement has the consequence thatP possibly an unstable position of the snap element is reached, so that R this again in the figure 2 and 3 position shown snar back> r> t. During this movement it can be observed that contacts 48 and 52, as was the case with contacts 50 and 54, are mutually aligned approach very slowly, namely immediately before the entire Schnappelenent 2 is snapped around. This in turn has with the result that the snap element with respect to the section on which the contact 52 is attached, only a small amount Has momentum, so that only minimal contact bounce, if any occurs when contacts 43 and 52 meet

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Figures 4, 5 and 6 of the drawing show a second embodiment of a switch according to the invention. The switch shown corresponds essentially to the first embodiment, with the exception that the snap element 2 is attached so that its longitudinal axis or its central axis is parallel to Longitudinal direction of the spring arm 36 lies. As in the first embodiment, stops 44 and 46 are used again, which, as in the first embodiment, serve as adjustable, stationary, electrical contacts, as they are for example are shown in Fig. 16 when the device is used as an electric switch. Associated electrical contacts 54 and 52 which are provided in the area of the connecting piece 10 on the snap element, preferably at points 56 and 58. The movable electrical contacts can also be connected to (with appropriate relocation of the associated stationary contacts) other locations of the snap element 2 are provided, as will be explained in more detail below. The setting the physical properties of the snap switch takes place in the manner as explained in connection with FIG. 1, i.e. by adjusting the parallel planes in which the. Ends of the stationary contacts 44 and 46 are up or down downwards, with respect to the plane in which the inner legs 12, 14 lie when the snap element is unloaded. By changing the width of the gap, the actuating forces and the contact forces of the snap element can be changed by the Adapt the switch to the desired application.

It is understood that certain physical properties of the Snap devices in accordance with the invention can be specified in the prior art by changing the thickness of the sheet metal part 4. Furthermore, the dimensions of the snap element can be changed, and the spring characteristics of the spring arm 36 as well as the position of the fastening element 42 can be changed. With regard

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the practically unlimited number of choices regarding the thickness of the various materials, their width and length, their spring constants, and their relative The width and length of the legs are not to be discussed in detail here. These details can be understood by those skilled in the art can easily be determined when operating in accordance with the teachings of the present invention. Below should however, as a guideline, the data of a snap-action switch that has been tried and tested in practice is given in more detail.

FIGS. 7 to 9 show a third exemplary embodiment of the invention, in which a tendon element is used again as in the embodiments described above and in which stationary stops 44 and 46 are also used again. (As explained above, the stops are normally electrical contacts 48, 50, ₇ waves interacting with movable contacts 52, 54 on the snap element 2.) In the exemplary embodiment under consideration, the snap element 2 is not attached to a spring arm. Instead, an actuating element 62 (for which a cylindrical push button is suitable) is provided, which has a flat end on which the snap element is provided with a newinde-

s
The fastening element 64 is fastened internally. The fastening element 64 reaches through the "opening" which is delimited by the recesses and spreads the inner legs 12, 14 of the snap element 2 apart, as does the shaft or the bolt surface 26 of the fastening element 22 does, whereby the Schnappelenent is biased in a suitable manner.

The actuating element 62 can be slidable in a usual socket or bore 66 in the upper part of a housing 68 of a switch, which is made of insulating Material can for example consist of a molded synthetic plastic. In the base slat 72 is in the

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Exemplary embodiment below the actuating element 62 Stop element 70 is provided, which is adjusted so that when the actuator 62 is depressed sufficiently is (as FIG. 8 shows) to bring the snap element 2 to snap over so that it differs from that shown in FIG Position reaches the upper position in which it rests against the stop 46 or in which the contact 54 on the Contact 50 is present, further movement of the actuating element 62 is prevented. The base plate 72 is also made made of electrically insulating in. Material. As in the previously considered exemplary embodiments, the contacts or the stops 44 and 46 can advantageously be screwed into the base plate 72 or into the housing 68, see above that they are easily adjustable.

Figures 13 to 15 show a fourth embodiment of the invention in which on a basis of electrical insulating material with the aid of a fastening screw, an electrically insulating collar or a socket 80 is attached is. Furthermore, a rigid but flexible support arm 82 is made of an electrically conductive spring material, such as e.g. PhosDhorbronze, provided as well as a second electrically insulating one Bushing 84. A spring arm 86 made of electrically conductive, elastic material such as phosphor bronze is also provided and an insulating collar 88 is also provided. These parts are all from the fastening screw 78 reached through, and a locking nut 90 is provided, around the parts with respect to the fastening screw 78 to back up. Instead of the screw connection 78, 90, a rivet connection can also be provided, if this is desired. The fastening screw 78 is surrounded by a suitable insulation, around ■ the support arm 82 and the spring arm 86 q against each other to isolate.

The support arm 82 serves firstly to close the snap-on element 2

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wear, which is designed in a similar manner to the snap element according to FIG. 1. The second function of the support arm 82 is to serve as an electrical power supply. The snap element 4 is fastened to the end of the support arm 32 with the aid of a fastening element 34, which can be designed similarly to the fastening element 22 according to FIGS. 10 to 12. Below the inner legs 12 , 14 there is provided a metallic collar or a bushing 92 through which the fastening element extends. The shaft of the screw-shaped fastening element is, as in the exemplary embodiments considered above, made sufficiently strong to press the inner legs 12, 14 apart and to produce a pretension in the SchnaopeleRient 2. A fastening nut 96 is provided in order to clamp the snap element 2 to the socket 92 and thus to the support arm 82 which is in electrical contact with the socket 92. In the area of the end of the snap element 2, an electrical contact 98 is attached by welding or riveting, the most favorable position being at point 56.

To increase the rigidity, the spring arm 86 is provided with side walls 106 over part of its length. Between 106 is the upper arm 100 of a U-shaped element

102, which also has a shorter lower arm 104. The fastening of the upper arm 100 to the spring arm 86 can be carried out in a simple manner with the aid of a rivet-shaped electrical Contact 103 take place, which - is arranged so that it is with the electrical contact 9 8 can cooperate. The shaft of the Contact 108 is used to produce a riveted connection between the upper arm 100 of the U-shaped / 1-2 and the spring arm 86 so / ie to produce an electrical connection to: the spring arm 86. A further connection is made with the aid of a threaded hole in the upper arm 100, through which the threaded shaft of an adjusting screw HO is screwed,

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the shaft through a suitable opening in the lower arm 104 reaches through, as the drawing shows. At the end of the shorter arm 104 is an electrically insulating stop -112 attached, which is preferably made of a synthetic resin or a junk material.

Another set screw 114 is screwed into the base 76 and is secured there by a locking nut /. The upper end of adjusting screw 114 further supports the support arm 82 from below _f v / ie this shows the drawing.

As in the embodiment according to FIG. transmission element 118 is provided, which in a housing opening or is slidably guided in a socket in the cover of the housing of the switch (not shown).

From the above description it is clear that in the fourth embodiment of the snap action of the snap element is not triggered by the fact that the actuating element acts directly on the inner legs. Instead moved an actuating element 113 moves the spring arm 86 downwards (in the drawing), whereby the contact 108 is moved downwards. The downward movement of contact 108 moves contact 98 downward. This will create the outer legs bent in the direction of the plane of the inner legs until the tipping point is reached. The snap element then snaps around, the contacts 9 8 and 108 being separated from one another. The other side of the SchnaOpelement lies down against the stop 112. The support arm 32 is sufficiently rigid or stiff, so that the fixed part during operation the inner leg maintains its position.

T-7 when the spring arm 86 is deflected downwards, it moves also the U-shaped member 102 downwards so that the stop 112 moves downwards. If then the qualification

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element 118 is released and moves upwards, so that the spring arm 86 also moves upwards, then moves also the stop 112 upwards. This exerts a force against the end of the snap element, see above that this is moved upwards until an unstable position is reached again. The snap element now schnapot back to the position shown in FIG. During this movement, when the actuating element 118 is gradually released is observed that the contact 93 moves to the contact 118 slowly approaches, which moves up with him. However, the upward movement of the stop 112 is greater than the movement of contact 108, so that a gap between the two contacts gradually closes. Immediately before the final closing as a result of this slow movement, however, the snap element reaches its unstable position, so that the contacts 9 8 and 108 come into contact with one another in the course of a snap action. Because of the short distance that the contact 98 covers in the direction of the contact 108 during the snap operation, contact 93 has little momentum, so that, if at all, only minimal contact bounce occurs.

For setting the path or the working stroke of the actuating element of the snap device or of the snap switch the actuating element 118 is moved down to the point at which the snap element snaps over. The actuating element is then slowly moved upwards by a distance that corresponds to the required difference in position is equivalent to. At this point, another upward movement of the actuator 118 is terminated and the Adjusting screw 110 is adjusted in such a way that the stop element 112 and thus the snap element resting thereon are raised are wrapped around the snap element and the contacts 9 8 and 108 rest against one another. Because the arm 100 of the U-shaped Element 102 is a spring arm, the adjusting screw then basically remains in the set position.

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If desired, however, the upper end of the adjusting screw can be used 110 a lock nut (not shown) may also be provided.

The force difference of the snap switch can be adjusted with the help of further adjusting screw 114 can be adjusted. The further the support arm 82 is moved upwards (in FIG. 13), the smaller is the force required to operate the snap switch is.

The force required to operate the snap switch is of course a function of the position of the support arm 82 and thus a function of the position of the snap element 2 with respect to the fixed contact 108. If consequently the other Adjusting screw 114 is moved downward (in Fig. 13) so that the snap element also moves downward, then a longer actuation path of the actuation element 118 is also required in order to enable the snap element 2 to snap over to bring it down, where it rests against the stop element 112. In addition, there is a correspondingly larger upward movement of the actuating element 118 required ^ to bring the snap element to snap over again, so that it assumes its upper position, under the action of the stop element 112, which the Schhappelement upwards presses.

In the embodiment according to FIG. For example, 4 to 6 can the spring arm made of about 0.25 mm thick tempered beryllium copper material exist. The snap element 2 itself can be made of a similar material and for example be about 1.4cm wide and about 2.1cm long in total. The distance between the center of the cutouts 16 formed "openings" on the inner edges of the inner Leg and the rear end of the snap element can be about 1.07cm and the distance between the center of the

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April 25, 1974 2421941

"Opening" and a line connecting points 56 and 58 may be approximately 0.79 cm. Points 56, 53 and thus the The center points of the contact 98 and the stop 112 have the center line of the snap element running in the longitudinal direction 4 a distance of about 4.3 mm.

The dimensions given above can also be selected with advantage in the other exemplary embodiments (in FIGS the dimensions for the snap element are the same as in the embodiment according to FIG. ₇ and the electrical contact 9 8 and the stop element 112 are located at points 56 and 58, respectively, which are shown in FIG. The Bet-Ktirrunaselement 118 has a distance of about 9.1 mm from the center of the fastening screw 78 and a distance of about 6.4 mm from the center of the rivet-shaped contact 103. The centers of the contact 98 and the stop element 112 are about 3.7 mm from the center line of the snap element 2, which runs in L rncrs rieh tuner. The length of the flexible part of the spring arm 86, ie the length of the part not provided with side walls / provided! the same, measured from the circumference of the collar 88 is about 4.45 mm.

At this point three essential features of the invention are intended Snap switch compared to the previously known snap switches, in particular compared to the snap switch according to U.S. Patent 3,213,228 will.

In the previously known snap devices, it is generally the case that the actuating element is moved in order to snap over of the snap element, the force or pressure between the contacts until immediately before

409849/0753

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2 ^ 4.1974

Snap action at a fairly steady rate decreases. At this point in time, i.e. immediately before the snap, the contact pressure in the prior art switches tested by the applicant was less than about 2 g. in the In contrast to this, the contact pressure in the case of snap switches according to the invention is immediately before the snap-over in the case of a corresponding one Adjustment 25g and more. The contact pressure can therefore be adjusted to values that are 10 times or more of the contact pressure in the known switches. In other words, an improvement of more than wildly 1OOO% achieved. But it also follows from this that snap arrangements or snap switches according to the invention have a far lower tendency to contact bounce than the previously known snap switches.

The second point to highlight is contact bounce. In the case of snap devices in which the snap elements cannot twist and bend relatively freely, as with the snap device according to the present invention, and in which the stops or contacts on both sides of the snap element are arranged coaxially, as is the case with the previously known switches, it is found that a moving contact does not move (i.e. no contact opening occurs) until the actual snap action takes place. This has the consequence that the movable contact a Reached relatively high speed as it moves towards its mating contact and finally at the end the snap action occurs on this. The high speed has the consequence that the movable contact is relatively has great energy, so that as a result of the generally existing Elasticity of the contact materials a contact bounce occurs. The contact bounce, in turn, often results in that the contacts melt together, so that the switch is unusable. In contrast, a snap switch moves according to the invention that contact with whose

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April 25, 1974

A circuit should be closed after snapping on, while the actuation of the actuation element gradually moves in the direction of its new position, up to a point at which there is still just no contact with the stationary contact a space meant that amounts to only a few thousandths of an inch.) ^T? then hen the Umchnamen occurs, the movable contact must therefore only be moved to gelanqen to irf contact with the stationary contact treks across a small ^. it 3I only builds This in turn has the consequence that, in contrast to the previously known snap-action switches, only slight contact bounce occurs, if at all.

For those execution examples where with a Schnappelenent is worked according to Fig. 1, it has been shown that under most operating conditions the best results are achieved when contacts 52 and 5 4 attached to the Schnapo element 2 approximately at points 56 and 51 are.

However, there are also unexpected improvements compared to the dai ™ state of the art _; when the electrical contacts 52, 54 are in areas of the snap element which are delimited by the center line, by the edges of the snap element, by a transverse line through the fastening element and by the outer edge of the connector IO.

In the four exemplary embodiments considered above, the snap element returns to its disengaged position when no more force is exerted on the actuating element. In order to achieve this must be the upper Anschlaa as showing all of the Figures are below the plane velche occupy the inner leg, before it is applied to a ^ ^r orspannunq. -If it is desired, however, there «the Schnaon

-27-

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element after actuation both in the upper position and also remains in the lower position, then only the lower end of the upper stop (for example the stop 46) lie above said level, and it must also be the upper end of the other stop (for example of the stop 44) lie below this level.

In all execution examples, when snapping on the Snap elements because of the non-coaxial arrangement of the stops 44 and 46, or the electrical contacts 48 and 50, there is no stop which can spring freely the snapping parts of the snap element via the rest position would prevent beyond. The 'Jaberschwingen or the Compared to the small dimensions of the snap switches, free swinging leads to a very large contact distance, whereby the effective interruption of a previously existing circuit in a snap switch according to the invention is improved.

Throughout the description and in the claims, the reference means that a snare element with two stable layers is used is that the snap element remains in each of the two positions until a force is again applied to the actuating element from it. is exercised.

A typical snap switch according to the invention, as shown in The .Figuren 4 to 6 is shown, has been thoroughly designed and successfully tested. Below are the main ones Dimensions, materials, forces and other measured values in tabular form summarized:

Sheet thickness ") approx. 0.25 mm

Sheet width i of the Schnaop- approx. 1.4 cm material J elements fully hoarded

BeryIlium-Kunfer

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Width of the outer legs

Width of the inner legs, -23-

about 2.5 now :. about 2.5 irari

Distance between the two levels in which the ends of the stationary stops lie

approx. 0.36 mm

Distance of the ends of the connections 44 and 46 from the center plane

the inner leg, with automatic approx. 1.62 mn or automatic return of the Schnaop approx. 1.98 mm

elements

Distance from the center of the attachment to the line connecting the stops approx. 5.08 mm

Distance each of the stops from

the center line approx. 5.33 mm

Distance from the center of the attachment to the support or Pivot point of the spring arm approx. 1.59 mm

Distance of the actuating element

from pivoting) approx. 6.35 mm

Length of the unreinforced section of the spring arm approx. 1.59

Width of the spring arm

Material of the spring arm

409849/0753 approx. 6.35 mm

fully hoarded ^ e ry 11 i um- Kut> ^ e r

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A 40 667 b -29-

Actuation force 420 g

In FIGS. 17 to 19, a fifth embodiment is shown Invention shown, in which additional devices are provided to connect and other movements of the Snap element to improve further and also to even more favorable results in terms of contact bounce come.

In this embodiment, a snap element 120 is used, which so far is substantially the qleichen construction shows how the snap element 2 according to FIG. I _{1 and} also as the outer legs 122 and 124, inner leg 126 and 128, elbows 132 and 134 connecting .to the Hufleren and inner legs, a connector 136 and one through recesses on the. inner. Legs limited mounting opening 130 are provided.

With the connecting piece 136, however, a preferably molded contact carrier element 138 is connected, which also consists of spring steel sheet. The contact carrier element 138 has a relatively narrow stem, one end of which is connected to the connecting piece .136 and at the other end of which an Oupiece 142 made of spring material is provided. The material for the additional Kontaktträqereleirent 138 is preferably the same material as that of the other parts of the snap element 120, and the width of the web 140 and the width of the OuerstHcks 142 can be approximately equal to the width of the outer legs 122,] 24.

The points 144 and 146 of the crosspiece 142 correspond to the Points 56 and 58 of the PchnaOpelement 2 in Fig.'l. On these Points if the snap element is in a switch

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April 25, 1974 2421941

is used, preferably electrical. Contacts _/ like contacts 52 and 54 in FIG. 16, attached.

Fig. 18 shows that the snap element 120 is attached in the embodiment under consideration in a similar manner as 2 shows this for the first embodiment. Those Parts of the two execution examples that correspond to one another, are · denoted by the same reference numerals; these parts are: the spring arm 36, the reinforcing crosswinds 38 of the spring arm 36 and the block 40 for fastening the spring arm and also the manually operable actuating element 42, the fastener 22 and the lock nut 39.

As in Fig. 2, stops 44 and 46 are also provided which are aligned with respect to points 144 and 146, respectively. The adjustment the attacks are done in the same way as this in the embodiments considered above to set the force difference and the path difference or the stroke.

For the sake of clarity, FIG. 19 once again shows a side view the snap device according to FIG. 18. As already mentioned above, the snap device is adjusted or the snap switch by adjusting the stops up and down with respect to the central plane or the neutral one Level of the snap element until the desired operating values are obtained.

With a snap switch according to Firr. 17 to 19 is the Contact pressure 27 g when the actuator 42 is moved so far down that to the point at which the snap of the snap element takes place, there is only a distance of about 0.254 ^ ". In comparison, the Switch according to FIGS. 2 to 6 with a conventional snap element a contact pressure of 23g exists under the same conditions. The static contact gap for the switch according to

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• 51 *

Figures 17-19 was approximately 0.79 cm compared to a contact spacing of about 0.724 cm for a snap switch with a conventional snap element.

Figures 20 to 23 show a sixth embodiment of the invention, based on which it should be clarified, as previously known Snap switches can be improved. With this one A snap element according to the US Pat 2 777 032 used. The snap element has two outer legs 150 and a middle leg 154. The one end of the outer limbs is each connected to the central limb 154 via a bend 156. If the free ends of the outer legs 152 are moved towards each other in the direction of arrows 158 (Fig. 21), i.e. when they be brought closer to the middle Schenjcel 154, then As disclosed in US Pat. No. 2,777,032, it can be observed that the snap element buckles so that it is now in a state in which the middle Leg 154 snaps up or down relative to a neutral plane.

Contrary to the teaching of U.S. Patent 2,777,032, the middle leg 154 extends beyond the free ends of the outer legs 150 and 152 and ends in one flexible crosspiece 160 to which the electrical contacts of the snap switch are attached at points 162 and 164. As in all previously considered exemplary embodiments, the contacts in the new exemplary embodiment are also in Set of switches in accordance with HR US patents 2 777 O32 and 3213 228, again not aligned coaxially.

The snap element according to FIG. 20 is fastened in FIG. 22 to a base 166 made of a suitable insulating material. It should be noted that the snap switch is somewhat schematic is shown in order to avoid an unnecessarily complicated drawing

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to avoid. In detail, there are 166 mounting sockets on the base 168 attached, and the free ends of the Husseren legs 150, 152 are on the sockets 16 3 by means of screws 170 attached, which openings 171 in the outer legs 150, 152 reach through. The sockets 168 are on the base 166 arranged at such a distance that the outer legs are pressed closer together, in the direction of the middle leg to a predetermined extent, so that the snap element comes into a pretensioned state, as he shown in FIG.

At the points 162 and 164 of the Ouorstücks 160 movable electrical contacts 172 and 174 are attached, stationary contact holders 176 and 178 are attached to the base 166 in such positions that they can carry stationary contacts 178 and 182, which with the movable contacts 172 and 172 respectively * ⁷ . 174 cursing.

In the embodiment under consideration, the stationary contacts are fixedly arranged with respect to the basin 166. It will be appreciated that the stationary contacts may be 178 and 182 also adjustable befestiat to its associated KontakttrHgern, for example on pins, which are in G ev / indebohrungen the contact carrier \ ^r be created, so that the fixed contacts with respect to the neutral plane of Schnanpelements in the desired ^r- 7eise can be adjusted, as described in the previously considered Ausf'ihrunrrsbeispiolen. If suitable manufacturing processes are used and given tolerances are observed, the distances between the contacts and the neutral plane of the snap element are given with sufficient accuracy even in the construction shown.

When the middle leg 154 of the snap element assumes its lower position, as shown in FIG. 22, the contacts are 172 and 178 in conductive connection with each other, while each other

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contacts 174 and 182 are spaced apart

As with the Construction according to U.S. Patent 2,777,032, one solid Attached support or a bearing pin 136, which the snap element touched approximately at point P and which is adjustable in a threaded hole in the base 166 and with a nut 188 is secured. The snap element can be actuated with the aid of a pressure element or an actuation element which take place at a short distance from point P. the side facing away from the crosspiece 160 acts on the base of the middle leg 154. If the snap element is so snaps over so that the middle limb 154 moves into the upper position, then the middle limb 154 remains behind Termination of the pressure on the actuating element 190 either in the upper position in which the contacts 174 and 182 abut one another, while contacts 172 and 178 abut one another are removed, or the middle leg 154 returns to its original position, so that the contacts 172 and touch 178 again. What happens in the individual case depends on the position of the contact 182 with respect to the neutral plane of the snap element, as discussed in US Pat. No. 2,777,032. If the operating conditions of the Snap switch should be adjustable, then the two can stationary contacts 178 and 182 each be mounted on their contact carriers so that they with respect to the neutral Are adjustable level of the snap element. In the embodiment 22 and 23, the contacts 178 and 182 are arranged in such a position that the snap element maintains the position reached after a snap. For this reason, as shown in Fig. 23, to return · tilt the snap element into the position shown in FIG. 23, a second actuating element 192 is provided, which is related on the bearing pin 186 is opposite the actuating element 190, '

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In the two embodiments shown in Figs. 17-19 and FIGS. 2O to 23 it can be seen that when the actuating element is moved s the snap switch shown there in a direction for causing the snap-on element to snap over and to open the closed contacts, the respective other contact on the snap element gradually moves onto its associated one stationary contact is moved. However, contact with this contact does not take place until the snap element actually snaps. When this snap occurs, the distance between the two contacts to be closed is so small that they close immediately when snapped on, with little or no contact bounce occurring.

With regard to the production and use of electrically insulating materials for base plates and housings as well as insulating collars and sockets, actuating elements, etc., all embodiments of the invention work in the usual way and with the usual materials. From the above Descriptio? 7 ^s clear that the invention achieves the intended aim and that the intended benefits are achieved.

It goes without saying that the invention is not limited to the structural details of the exemplary embodiments considered is, which have only proven to be particularly advantageous and the explanation of the basic idea of Invention serve. It is also understood that numerous possibilities are available to those skilled in the art, those shown Modifying exemplary embodiments without departing from the basic concept of the invention.

409849/0753 -35-

Claims (15)

A 40 667 b April 25, 1974 2421941 Claims Snap device, in particular snap switch, with a pretensioned snap element made of a resilient flat material, with outer legs arranged at a distance from one another, with a center leg arrangement which is connected at one end of the snap element to one end of the outer legs via curved pieces, with at least one element via which the other ends of the outer legs are held with respect to the central leg arrangement in such a position that there is a pretensioning of the snap element, with fastening devices effective approximately in the middle of the snap element for fastening the snap element to a holder, with at least one actuating element for tilting the snap element from a first into a second stable position and with at least one stop connected to the holder, with which the snap element interacts, characterized in that a first stop (44) is provided which is connected to a first Pu nkt (56) cooperates on one side of the snap element (2) when this is in its first stable position that a second stop (46) is provided, which with a second point (58) on the opposite side of the snap element (2nd ) cooperates when this is in its second stable position that the first point (56) lies in a first area of the snap element, which is located at the end of the snap element facing away from the curved pieces (18, 20) and which through the longitudinal direction of the snap element (2) running center line of the same on the one hand and ^{limited by a transverse thereto and by the fastening devices c} (2 ^ iYr aliaeYersMWs ISt ₇ and that the second point (58) lies in a second area at the same end of the snap element (2), which 409849/0753 ~ ³⁶ " A 40 667 b lc-h -Jb- April 25, 1974 2421941 is also bounded by the center line and the transverse line and which is on the other side of the center line lies. 2. Snap device according to claim 1, characterized in that at least one of the stops (44, 46) as electrical Contact (48, 50; Fig. 16) is formed and that with each of the contacts (48, 50) a corresponding contact (52 or 54) cooperates on the snap element (2). 3. Snap device according to claim 1 and 2, characterized in that that the actuating element (42) acts on the central leg arrangement (12,14) in such a way that it is in such a direction is moved with respect to the outer legs (6, 8) that the snap element (2) is in an unstable one Position is guided and when approaching this unstable position both bends and twists. 4. Snap device according to claim 3, characterized in that the area which is not on the assigned stop or contact is applied when bending and twisting the snap element (2) is moved in such a way that that it approaches its assigned stop or contact without touching it, however, before the snap action of the Snap element (2) takes place. 5. Snap device according to one or more of the preceding claims, characterized in that the central leg arrangement comprises two inner legs (12, 14), that the curved pieces (18, 20) each have one end of an outer leg (6 _f 8) and an inner leg (12,14) connect with each other that the at least one element, via which the other ends of the outer legs (6,8) are held in predetermined positions with respect to the inner legs (12, 14), a connecting piece (10) from a 409849/0 7'5 3 " ³⁷ ~ A 40 667 b -j / - April 25, 1974 2421941 is flexible metal strip, the ends of which with the ends facing away from the curved pieces (18, 20) of the outer Legs (6, 8) are twisted, and that the first • and the second point (56, 58) or the corresponding Contact between the center line of the snap element (2) and the end of the associated outer leg (6,8) lie on the connecting piece (10). 6. Snap device according to claim 5, characterized in that that the inner legs (12, 14) are spread further apart than in the case of the non-prestressed Snap element (2). 7. Snap device according to claim 8, characterized in that the fastening devices have a movable one Include spring arm (36), which with the holder (40) on the one hand and with a central portion of the inner Leg (12, 14) is connected on the other hand. 8. Snap device according to claim 7, characterized in that that the actuating element is a slidably mounted push button (42) which on the spring arm (36) at a point between the holder and the Affixing point acts on the inner legs (12, 14). 9. Snap device according to claim 7 and 8, characterized in that that the inner legs (12, 14) and the outer legs (6, 8) essentially under a right Angle to the longitudinal axis of the spring arm (36) run (Fig. 2). 10. Snap device according to one or more of the preceding Claims, characterized in that the actuating element (118) is connected to devices 409849/0753 -38- A 40 667 b ■ k-b -3o- April 25, 1974 2421941 which with respect to the holder (78, 80, 84, 88, 90) are movable that one of the stops (112) on this movable means is mounted and through this in opposite directions to bring about a Snap action against the snap element (2) movable and that the central leg arrangement (12, 14) of the snap element (2) is adjustable (82, 116) on the holder is attached. 11. Snap device according to claim 10, characterized in that the other stop or contact (108) with respect to of the first stop (112) is adjustable (Fig. 13-15). 12. Snap device according to claim 10 and 11, characterized in that that at least one of the stops (108, 112) is a first electrical contact (108) and that a second electrical contact (9 8) on the snap element (2) is provided, which occupies such a position in one of the areas that it is with the first Contact (108) can be brought into contact when the snap element (2) is in one of its stable positions ^ and that by moving the first contact (108) in the direction of the snap element (2) a snap-over occurs the same can be brought about (Fig. 13-15). 13. Snap device according to one or more of the preceding Claims, characterized in that the snap element (120) has a cross piece (142) which consists of a flexible metal strip and extends transversely to the central axis of the snap element (120) that the cross piece (142) has free end regions and that the end regions of the cross piece comprise the first and second regions of the very "element (120) and associated with it Stops (44, 46) interact (Fig. 17-19). . 409849/0753 -39- A 40 667 b 14. Snap device according to claim 13, characterized in that that the crosspiece (142) is connected to the other parts of the snap element (120) via a web (14O) is. 15. Snap device on one or more of the preceding Claims, characterized in that the central leg arrangement is formed by a single central leg (154) is formed that the bow pieces (156) one end of the central leg (154) each with one end the two outer legs (150, 152) connect and that the other end of the central leg (154) in one Cross piece (160) ends, which has free end regions that form the first and second regions of the snap element form and interact with associated stops or contacts (178, 182) (Fig. 20 - Fig. 23) 409849/0753