DE3150210A1 - ELECTRIC SNAP SWITCH - Google Patents

Description

"Electrical snap switch"

The invention relates to an electrical snap switch, consisting of at least one pair of spaced-apart fixed contacts attached to the housing, a movable contact bridge with molded on both ends Contact platforms with at least one contact on each platform and one in the middle between the fixed contacts, Plunger-like trigger as an actuating element, which also serves as a carrier for the double-interrupting contact bridge, which is moved with a snap.

Snap-action switch with connecting elements, which are both on the contact platforms as well as on the actuating member are blade-mounted have the disadvantage that the moving contact bridge system with the actuating member a relatively rigid system, which only has a degree of freedom of movement namely in the direction of actuation. In the course of the frequently decreasing switching loads towards the mV and mA ranges, with increasing demands on reliability in terms of volume resistance, it is advantageous to use the individual contact

■ provide with twin contacts. The invention lies in the The object is to store the connecting elements on the contact platforms and / or on the actuator that the contact bridge system is freely movable on all sides and all twin contact points rest on the fixed contacts with the smallest possible contact differences.

Since parallel with increasing demands on the contact reliability The demands on the accuracy of the switching time have also increased and therefore inevitably readjustment when replacing the snap-action switches is required in systems with predefined switching times, options are now required on the snap-on switching elements of outside, that is, to carry out this adjustment without removing housing parts and the like.

The invention is also based on the object, in addition to the increase the contact reliability by ensuring the four-point support of the contact bridge, the readjustment of the switching point

to provide a positive opening and the post stroke after pressing the actuator and to enlarge the completion of the snap-action.

With snap switches according to the preamble, two basic principles ', and. although the one time with resilient contact bridges and rigid connecting elements (between contact platform and actuator) and the other time with rigid contact bridges and resilient connecting elements, differentiated.

Snap switches with a resilient contact bridge are from the German Patent specification 975 831 known, a snap switch with two resilient contact bridges, -which thus becomes a two-circuit changer, is in the German patent 17 65 712 described. A snap switch with one or two rigid contact bridges and resilient connecting elements is shown in German OS 28 17 815.

What these principles have in common, as shown there, is that the Contact platforms with one-bridge design one contact each for the NC and NO function, with two-bridge design only one each carry one contact per contact point. A doubling of the contact points to so-called twin contacts even if there are two

lateral cutting edge storage of the connecting elements would be with the DT PS 17 65 712 is still conceivable. But since such snap switches must also be provided with devices for positive opening, divide according to the requirement of VDE 0660 (that as a switch with inevitable opening Such switches are to be understood, the contact pieces of which when switching off at least on a part of the actuation path without interposition elastic drive links are reliably separated) elastic, d. H. resilient contact bridges.

A doubling of the contacts to twin contacts required so far Special constructions as described in English patent 1,593,948. The required there. Separation of the contact system from the jump system but brings with it major disadvantages in terms of contact reliability small actuation speeds as has been explained in the magazine ETZ Volume 101 (1980) Issue 4 on page 221 Fig. 2.

In all of the aforementioned snap switch designs, there were also no device lengths available, the time of switching, i.e. the Time of the snap to adjust. Only OS 29 13 913 shows a possibility in this regard. However, since this is a Snap switch acts in which the contact system is separated from the snap mechanism, this principle is based on the aforementioned For reasons of contact security not optimal at slow actuation speed. In addition, the adjustment of the snap point is only there at removed housing or if there is a corresponding opening in the housing.

The object is achieved according to the invention in that the between the contact platforms of the contact bridge - or between contact bridges positioned one above the other and insulating pieces the actuating member clamped connecting elements on the contact platforms or insulating pieces are knife-edge-mounted in a known manner and point-mounted on the actuating element.

This gives the contact system the option of twin contacts mediates to level off to the position of the fixed contacts.

'»Slight remaining differences in position of the four support points can also be compensated for with the contact bridges, which are massive but easily twistable in the contact system. A particularly preferred one Embodiment of the point support, with regard to a spatially fixed fixation of the pendulum center and thus prevented lateral Moving out the contact bridge system is characterized in that the portion of the actuating member on which the connecting elements rest, is designed to be rotationally symmetrical, and the supports of the connecting elements on the rotational body are each preferably in the form of a circular arc Have recess whose radii are larger than the radius of the rotation body at the support point.

For the construction that requires the least number of components, it is useful to that the actuator is made in one piece or that for A rotational body is pressed into the actuating member to achieve a wear-optimized design. In this case the part will the actuator into which the rotary body is pressed,

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with regard to friction and wear behavior to the friction partner "housing" optimized, the rotational body in relation to its friction partner "connecting element" .

Is the pressed-in rotational body dimensionally to a tolerance limit position fixed towards, a snap adjustment can be achieved in such a way that that the end position of the rotary body pressed into the actuator with an adjusting screw in the direction of its longitudinal axis and against the Contact system or is displaceable towards the contact bridge.

It can be useful to move the snap point in both directions to adjust. For this case, it is proposed according to a further development that the rotary body is freely longitudinally displaceable in the actuating member is arranged and against the force of a pressure spring supported between the rotating body and the actuating member with a Adjusting screw is adjustable.

In this case it is useful that the preloaded force of the compression spring has a higher numerical value over its entire adjustable range than that in the direction of the compression spring, but acting in the opposite direction Force component of the snap springs and / or the resilient contact bridges.

Furthermore, in order to achieve an additional overtravel, the compression spring is to be dimensioned so that after pressing the snap switch via the actuator and reaching the end position of the contact system and the rotary body, the actuating member may have an additional overtravel by compressing the compression spring up to its block height.
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Is the contact security of those provided with twin contacts sufficient Contact points and the free mobility of the point-supported contact system, which also increases the contact reliability, for very small ones Actuating speeds not yet reached, the between the actuating tappets and rotating body used compression spring be dimensioned so that they along the path of the actuators in comparison to that of her counteracting component of the snap springs or the resilient

Contact bridge exerted force in the area of the snap point stronger, towards the end position of the actuator is weaker than this component and that it has a flatter characteristic than the snap spring or has the resilient contact bridges. 5

In this embodiment, too, the snap points are adjustable that the point of equilibrium between the compression spring and the counteracting component of the snap springs and / or contact springs is adjustable with an adjusting screw.

In all possible embodiments, it makes sense that a degree of freedom of the pendulum movement of the contact system or bridge is provided by noses of the insulating piece, which may be in frictional contact with the housing parts step, is narrowed.

The exemplary embodiments of the invention are explained with reference to the figures. The individual figures represent:

Fig. 1 is an illustration of a snap switch with cut off Cover, cut contact system and a partial cut through the actuating element with a pressed-in rotary body.

The left half of the figure shows the position of the contact system when the actuator is pressed; the right side the rest position of the snap switch,
25th

FIG. 2 shows a section through the switch of FIG. 1 to the right of the center line according to line I - I, to the left of the center line, according to line II - II,

3 shows a section through the switch of FIG. 1 along the line III - III,

Fig. 4 sections through the point support (rotation body and connecting element),
35

Fig. 5 is a section through an actuator and in principle the Representation of a contact system with only one contact bridge and

Fig. 6 is a section through an actuator with a longitudinally displaceable Solid of revolution.

The snap switch shown in Figures 1 to 3 comprises a housing 1 and a cover 2 which is held in place in bores 4 (FIG. 1) of the housing 1 with clips 3 (FIG. 2). An actuator 5 is guided on the upper collar 6 (FIG. 1) of the housing 1 and over webs 7 (FIGS. 1 and 3) in grooves 8 (FIG. 3) of the housing 1. A cylinder spring 9 (FIG. 1) presses the actuating member 5 into its rest position, the stop 10 (FIG. 1) being the rest position of the actuating member 5 fixed.

The fixed contacts 11, 12 are assigned to the normally open contact (closer), the fixed contacts 13, 14 the normally closed contact (NC contact). Between the fixed contacts on the one hand 11, 12 and 13, 14 on the other hand is freely movable the contact system consisting of contact bridges 15, 16, which over the Insulating body 17, 18 are joined to form a unit. The two snap springs 19, 20 are between the blade bearings 21, 22 of the insulating body 17, 18 and the two point bearings 23, 24 clamped in the rotary body 25.

With the help of Fig. 3, the construction of the contact bridges is closer explained, which shows the contact bridge 15 in plan view: The contact platforms Twin contact pairs 26, 27 and 28, 29 assigned to 15a and 15b are mutually via the narrow webs A1 and A2 and electrically connected to each other with the likewise narrow webs B1 and B2, the contact system is enabled via the point bearings 23, 24, largely on the possibly existing differences in position between the contact pairs 26, 27/28, 29 and the four support points of the fixed contacts (the two support points of the fixed contact 11 are designated in Fig. 2 with 11a and Hb) to adapt, to the extent that until three of the four contact points have come into contact. Since the point bearings are relatively easy to twist through the narrow Bars Al, A2 or Bl, B2 deliberately torsion-unstable constructed contact bridges allow, the fourth contact point also comes to rest in the course of the snap action with small contact force differences.

The free wobble mobility of the contact system requires guidance to the housing parts 1, 2. For this purpose, the lugs 17a and 17b are formed on the insulating body 17, the lugs 18a and 18b on the insulating body 18.
5

The different ways a switch of the presented construction to be attached are described in German patent application P 31 39 701.8 and HGm G 81 29 211.2.

In Fig. 4, the point bearing points 23, 24 are between the connecting elements, in the example shown, the snap springs 19 and 20 and the rotary body 25, explained in more detail. This one has the scope circumferential groove 30. To avoid that the snap springs 19, 20 migrate in the direction of arrow C, d. H. leave their planned symmetry, the snap springs have circular arc-shaped cutouts 31, the radii of which are operational to ensure the point bearing points in all possible positions of the rotary body 25 for the position of the connecting elements 23, 24 must be equal to or greater than the radius of a circle which is given by the points 24, 32 on its circumference, The points 32, 33 are the points of intersection of the line X1-X2 with the line Y1-Y2 and, on the other hand, the lines Y1-Y2 with the circumferential line Z.

With Fig. 5 the possibility is explained, the spatial position of the im Actuator 5 firmly pressed-in rotary body 25 to adjust.

The rotational body 25 is in the course of assembly until it rests Surface 34 is pressed into a bore 5a of the actuating member 5. The pin 35 of the rotary body 25, which projects into the bore 5a, has Undercuts 36 to achieve a clear interference fit. When the parts 5 and 25 rest on surface 34, this results in a pre-travel path the distance D and the distance E as the overtravel. The theoretical snap point results when the dimension of the distance D has become zero.

In the example of FIG. 5, the contact system consists of only one contact bridge 49, on which the snap springs 50, shown symbolically, attack via insulating pieces 52, 53 via blade bearings 21, 22. the Fixed contacts are denoted by 54a, 54b and 55a, 55b.

- 11 -. <····

In terms of design, it is useful for the adjustment shown as an example, to lay the individual part dimensions determining the advance path in such a way that an adjustment always has to assume that the advance path is too large.

To reduce the distance D, the screw 37, which is at 38 on rests on the rotary body 25, adjusted so that the rotary body 25 is pressed out of the bore 5a in such a way that the undercuts 35 dig into the hole 5a. The course D is then reduced by the amount by which the rotary body 25 from the actuating member 5 is pressed, the overrun increases by this distance. The switch-back point results from the sum of the adjusted Line E plus the contact opening F. Of course, it is possible at any time to close the rotating body 25 and screw 37 in one piece do. This only requires the rotary body to be designed in such a way that it can be displaced longitudinally and is secured against accidental damage Turning provided in the actuator 5 is used.

In FIG. 6, the rotary body 39 is freely displaceable in the longitudinal direction G stored in the actuator 40, the path of which is predetermined by the stops and 42. For this example, the return spring was arranged at the lower end 44 of the rotary body 39. The rotation lock is given by a square 39a.

When dimensioning the compression spring 45 in such a way that its spring force over the entire adjustable range over the spring force component of the snap spring, which acts against the force of the compression spring 45, is, there are snap conditions similar to FIG. 5. The difference to the construction according to FIG. 5 lies in the quite significant advantage that after reaching the end position of the rotary body 39 - corresponds Distance D plus E of FIG. 5 - the actuating member 40 can be pushed in even further until either it rests at 42 or the compression spring rests 45 turn to turn. With the adjusting nut 46, which at 47 is on a collar of the actuator and against which the compression spring 45 presses the adjusting nut 46, the snap time can be adjusted in both directions.

When dimensioning the compression spring 45 in such a way that it runs along the path of the actuating member compared to the counteracting component of the snap springs and / or the resilient contact bridge exerted force in the area of the snap point stronger, against the However, the end position of the actuator is weaker than this component and that it has a flatter characteristic than the snap spring or has the resilient contact bridges, a so-called double snap function results, as described in DT OS 29 13 913. The difference between the solution according to the invention and that disclosed in DT OS 29 13 lies in the enormous advantage that none in the actuating element bearings to be introduced are required and the adjustment of the snap time from the outside via the adjusting nut 46 is possible. The measure of the advance path results in this construction from the distance D shown in Fig. 5 minus the path X (not shown), around which the compression spring 45 can be compressed by the shoulder 48. The switch-back point is also reduced by this amount X, i.e. H., that the difference path, which is normal (when not by the snap spring force component compressible compression spring 45) corresponds to the contact distance F (Fig. 5), increased by the dimension 2 times X, i.e. F + (2 times X) amounts to. The function of the positive opening device can be seen in FIG.

· “And 2 are explained. The two positive opening levers 56, 57 are at 56a and 57a mounted in the housing 1 and cover 2, respectively.

After pressing the actuator 5 and reaching the switchover point of the contact system, but prevented for some reason Switching, comes after having covered a further distance, which takes into account the operationally occurring burn-off on the contacts, at 58 or 59 the rotating body is in operative connection with the contact bridge and thus forcibly triggers an opening of the normally closed contact (NC contact).

6 figures
11 claims

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Claims (1)

SDS - Elektro GmbH '"TO. December 1981 81/12/1 Claims Electrical snap-action switch, consisting of at least one pair of spaced-apart fixed contacts attached to the housing. platform with at least one contact on each platform, as well as a plunger-like trigger located in the middle between the fixed contacts as an actuating element, which also serves as a carrier for the snap-moving, double-interrupting contact bridge, characterized that between the contact sites of the contact bridge - arranged or between superposed contact bridges (15, 16) positioned insulating pieces (17, 18) and the actuating member (5, 25/39, 40) clamped connecting elements (19, 20/50, 51) to the contact platforms or insulating pieces (17, 18/52, 53) are knife-edge-mounted in a known manner and point-mounted on the actuating element (5, 25/39, 40). Ί 2. Electrical snap-action switch according to claim 1, characterized in that the section of the actuating member (5, 25/39, 40) on which the connecting elements (19, 20/50, 51) rest, is rotationally symmetrical and the supports of the connecting elements ( 19, 20/50, 51) on the rotating body (25, 39) each have a preferably circular arc-shaped recess (31), the radii of which are larger than the radius of the rotating body (25, 39) at the support point. 3. Electrical snap switch according to claim 1 and 2, characterized in that the rotary body (25, 39) is pressed into the actuating member (5, 40). 4. Electrical snap-action switch according to claim 1 to 3, characterized in that the end position of the rotary body (25) pressed into the actuating member (5) can be displaced with an adjusting screw (37) in the direction of its longitudinal axis and against the contact system or against the contact bridge (49) is. 5. Electrical snap-action switch according to claim 1 and 2, characterized in that the rotary body (39) is arranged freely longitudinally displaceable in the actuating member (40) and against the force of a between the rotary body (39) and the actuating member (40) supported compression spring (45) with a Adjusting screw (46) is adjustable. 6. Electrical snap switch according to claim 1, 2 and 5 marked ichnet that the pretensioned force of the compression spring (45) has a higher numerical value over its entire adjustable range than that in the direction of the compression spring (45), but oppositely acting force components of the snap springs ( 19, 20/50, 51) and / or the resilient contact bridges. 7. Electrical snap-action switch according to claim 1, 2, 5 and 6, characterized in that the compression spring (45) is dimensioned so that after actuation of the snap-action switch via the actuating member (39, 40) and reaching the end position of the contact system and the rotary body (39 ), the actuating member (40) by compressing the compression spring (45) under certain circumstances has an additional overrun path up to its block height. 8. Electrical snap-action switch according to claim 1, 2 and 5, characterized in that the compression spring (45) is dimensioned so that it is along the path of the actuating members (39, 40) in comparison to the counteracting component of the snap springs (19, 20/50, 51) or the resilient contact bridge exerted force in the area of the snap point is stronger, towards the end position of the actuator "(39, 40) but weaker than this component and that it has a flatter characteristic than the snap spring (19, 20 / 50, 51) or the resilient contact bridges. 9. Electrical snap switch according to claim 1, 2, 5 and 8, characterized in that the point of equilibrium between the compression spring (45) and the counteracting component of the snap springs (19, 20/50, 51) and / or contact springs with an adjusting screw (46 ) is adjustable. 10. Electrical snap-action switch according to claim 1 and the following, characterized in that a degree of freedom of the pendulum movement of the contact system or bridge (49) by lugs (17a, 17b / 18a, 18b) of the insulating piece (17, 18), which may be in frictional contact step with the housing parts (1, 2), is narrowed. 11. Electrical snap-action switch according to claim 1 and the following, characterized in that in the housing parts (1, 2) positive opening levers (56, 57) are mounted, soft after pressing by the actuator (5, 25/39, 40) and after not done Snapping over the contact system creates a non-positive connection between the rotating body (-25, 39) and the intermediate insulating piece (17, 18/52, 53) or the contact system.