DE1281530B - Pressure dependent electrical switch - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

HOIh

German class: 21 c - 40/04

Number:
File number:
Registration date:
Display day:

P 12 81 530.4-34 (B 79275)

November 11, 1964

October 31, 1968

The invention relates to a pressure-dependent electrical switch that has at least one between the associated pair of contacts is equipped with protruding contact spring from the outside influenceable organ over both under the action of a spring as well as under the Effect of at least two mutually associated directional springs standing tongue can be controlled, wherein one directional spring a strong and the other, additional directional spring only a weak spring force having.

In connection with such pressure switches, an embodiment has become known, for example, in which two directional springs arranged concentrically to one another and connected in parallel are provided, of which the inner spring has only a weak spring force. First of all, there is only the weak spring in this construction comes into action, only the spring constant (restoring force) of this weak spring is initially used effective. However, as soon as the strong spring also comes into action, the sum of the two spring constants becomes effective. As a result of this parallel connection of the two springs, it is possible, one after the other to allow different spring forces to take effect, but the scope given is sufficient often not over yet.

Thus, the invention is based on the object, with such a pressure switch also with a relatively high switching point of, for example, 100 mm WS and more, a switch-back point achieve which is as close as possible to the zero point, for example a value of only 20 mm WS. There now a relatively high switching point hard spring with a correspondingly large spring constant and only a small spring deflection is required, switching back close to the zero point is only unsafe.

To now close to the zero point the effective spring constant still over the measure of the spring constant To be able to reduce the weak spring addition, it is proposed according to the invention, the two To switch direction springs one after the other, with then the stroke of the weaker directional spring is limited. As a result of this construction results in the area of the zero point is an entire spring constant

Pressure dependent electrical switch

Applicant:

Walter Beck K. G.,

Control and telemetry equipment,

7000 Stuttgart-Möhringen, Leinenweberstr. 42

Named as inventor:

Walter Beck, 7000 Stuttgart-Möhringen;

Karl Roll, 7022 Leinfelden

Cges -

C ₁ · C ₂

C ₁ + C ₂

where the spring constant of the weak spring is denoted _{by C 1} and that of the strong spring _{is denoted by C 2.} On the basis of these relationships between the spring constants, it follows that the entire

so the spring constant C _{tot is} in any case still smaller than the spring constant C _{1 of} the weak directional spring. However, as soon as the stroke limitation of the weak directional spring becomes effective, only the strong directional spring with the spring constant C ₂ exerts a compressive force.

In a switch of this type, it is useful between the two, preferably helically Directional springs have an abutment on both sides, advantageously a washer, one having a collar Intermediate piece or the like. Arranged.

In order to limit the stroke of the weaker directional spring, at least one spacer is advantageous to provide that, for example, as an arranged on one abutment of this weaker directional spring, into the interior of the spring protruding pegs or also as a pin surrounding the spring Spacer sleeve od. The like. Can be formed, on whose end face then the other abutment of the weak spring.

If the expansion stroke of the stronger deformation spring is also limited, it is possible to give this stronger deformation spring a bias. As a result of this increased bias of the strong directional spring, the series connection of the two axially one behind the other directional springs can be canceled again, so that initially only the spring constant C _{1 of} the weak spring becomes effective and the effect of the spring constant C _{2 of} the strong spring only starts as soon as the stroke of the weak directional spring is limited and the organ that can be influenced from the outside now

809 629/1156

3 4

exclusively on the stronger directional spring one in the F i g. 2 to 4 illustrated manner with the Exerts counter pressure. strong direction spring 18 is connected in series.

In this context, it is finally conceivable, in the case of the FIG. 2 illustrated embodiment

the strong deformation spring of a sleeve or the like. The strong directional spring 18 is based on the shape to surround, at the outer edge then a radial 5 switching tongue 12 from, the weak directional spring 19 inwardly protruding collar is arranged, which, however, is on the serving as a fixed abutment even that between the two bolts 17 one behind the other. Between the two directorates Common abutments 18 and 19 located on springs are used as a common abutment engages behind the bearing of both springs and for this one a disk designated 21 is arranged, which forms a fixed system. io early also the guidance of the two springs 18 and 19 From the foregoing it can be seen within which the can bottom 14 adjoins these features according to the invention of the pressure switch surrounding the two springs 18 and 19 Of course, it is not only used for a part 22 of the connecting piece 15.

pole pressure switch, but also in connection with the stroke H of the weak direct

The bolt 17 instructs the use of a multi-pole pressure switch to limit the function spring

are real. its end face facing the spring 19 one in

In the drawing, for example, this spring 19 protruding pins 23 are on, on Shapes of the switch according to the invention shown. the end face 24 of which the disc 21 rests as soon as

It shows that exerted by the membrane 5 via the plunger 7

F i g. 1 the section of the design of a print is sufficiently large in itself. The possible stroke H of the known pressure switch with a single weak spring 19 is determined by the distance

Direction spring is equipped, between the end face 24 of the pin 23 and the

F i g. 2 shows an excerpt from FIG. 1 determined in the opposite side of the disc 21, on a larger scale, but one directional

spring by two directional springs 18 and 19 connected in series tion springs is replaced, the switching of the switch tongue 12 and the con

F i g. 3 and 4 a further embodiment. Clock spring 11 shows the following illustration:

In the case of the FIG. 1 shown in section If the plunger 7 is provided with a form-pressure-dependent electrical switch through the membrane 5, the thrust is given in the direction of the arrow 25, this switch housing is made in the usual way from a cylindrical box designated 30 advance against the action of the two springs 18 1 and one with 2 and 19, the total restoring force of which is determined by the designated cover, which has an inlet connection 3 for total spring constant C _tot . As soon as the medium controlling the switch, for example in the further course of the plunger advance, has air or a liquid. Between the associated pressing together of the can edge 4 and the lid 2, a membrane, denoted by 5, is also arranged on the two springs 18 and 19, which has applied to the side 24 of the pin 23, the stroke H is known Way reinforced by a sheet metal plate 6 and limited by the weak spring 19 and switched off its effect with a arranged on this sheet metal plate 6. But this means that the plunger 7 is now equipped. only the strong directional spring 18 and its spring

Furthermore, in the socket 1 _{, a pair of contacts 8, 9 is effective at 40 constant C 2} , which again has a behavioral order. Between these two contacts 8 and 9, a switching point that is noticeably high, protrudes firmly into the wall of the can on one side, on the other hand that which is exerted on the membrane 5

tensioned contact spring 11 into it, which in their pressure after, so causes the stronger direction F i g. 1, a return stroke contact 8 is applied to the upper rest spring 18 as a result of its restoring force. This contact spring 11 is a with 45 of the plunger 7 as well as the membrane 5 against 12 designated, also in the can wall in the direction of the arrow 25, initially assigned to the pointed switch tongue, which in turn exclusively the spring constant C _{2 of} the star known Way by a direction spring 18 ken in the contact spring 11 becomes effective. Swinging through shortly before the rectangular recess that is located, however, can reach the intended switch-back point. Furthermore, a switch 50, designated by 13, also detaches the disc 21 from the front spring, which is located on the one hand on the side 24 of the pin 23, so that now both free ends of the switch tongue 12 and on the other hand on springs 18 and 19 in Action occur and now the inner edge of the recess located in the contact spring 11 again supports the entire spring constant C _total. is. _{The total} due to the low spring constant C

The bottom 14 of the can 1 also has a relatively large spring travel-related tongue above the 55 12 a connecting piece 15 with an inner bar also always ensures an exact downshift thread 16, in which a designated 17 bolt when the switchback point is very close to zero is screwed in. This bolt 17 serves as a lies.

adjustable abutment for a directional spring 18, In addition, the following numerical example may illustrate the

which is supported one behind the other in a known manner on the switching tongue 12 60 according to the invention and the directional springs 18 and 19 controlled by the diaphragm 5, the ram 7 counteracts. borrowed: Should, for example, the switching point for a

Now the switching range of this a high spring pressure of 100 mm Ws, the switch-back point, on the other hand, force-exhibiting directional spring 18 with the spring- at the very low pressure of only 20 mm Ws constant C ₂ lie in the manner already discussed above 65 To expand the strong directional spring 18, this strong directional spring 18 is assigned a spring constant C ₂ = 100 g and the weak directional spring 19 has no further weak directional spring 19 designated as 19 with a spring constant C ₁ = 50 g, assigned to a spring with the spring constant C ₁ , based on these values results in the background

interconnection of the two springs 18 and 19 results in a total spring constant

-β it

QC ₂
C ₁ + C ₂

50 g x 100 g
50 g + 100 g

= 33g.

This total spring constant C _ges isi thus still less than the weak spring 19 g of the associated spring constant C ₁ = 50, whereby then the greater spring travel is limited.

What the embodiment according to FIG. 3, in this case the two springs 18 and 19 are merely interchanged in their arrangement, with an intermediate piece designated as 26 being provided as a common abutment instead of the disk 21, which protrudes over the edge 27 of the sleeve-like connecting piece lower part 22 and a collar 28 having. A collar 29 projecting radially inward is arranged on the edge 27 of the lower part 22, the clear width of which is smaller than the outer diameter of the intermediate piece collar 28. Furthermore, on the end face of the intermediate piece 26 facing the weaker directional spring 19, a pin designated 31 is arranged, which protrudes into the interior of the directional spring 19 and in the same way as in the embodiment according to FIG. 2 to limit the stroke H of the weaker directional spring 19 is used. The mode of action of this in FIG. 3 is again the same as it has already been explained in detail in connection with the embodiment according to FIG. 2 was explained.

If now in the F i g. 4, the bolt 17 serving as a fixed abutment for the strong directional spring 18 is screwed deeper into the connecting piece 15, this causes a bias of the directional spring 18, with the intermediate piece 26 then fixed with its collar 28 on the now serving as a fixed abutment Collar 29 of the sleeve 22 applies. By shifting the intermediate piece 26, the previous stroke H is reduced to the dimension h .

In the case of an advance of the plunger 7 in the direction of arrow 25 via the diaphragm 5, as already described above, the compressive force exerted by the diaphragm 5 initially overcomes the restoring force of the weak directional spring 19, only the spring constant C _{1 of} this spring 19 being effective is. As soon as the stroke h of this weak spring 19 is limited by the plunger 7 striking the end face of the pin 31, the weak spring 19 becomes ineffective. With a further advance of the plunger 7, only the restoring force of the strong directional spring 18 is _{now to be overcome, with only the spring constant C 2 of the spring 18 now being effective.} The same applies of course in a lessening of the force acting on the diaphragm 5 pressure and the consequent return stroke of the diaphragm 5 and of. The plunger 7. It follows that the effect of the common spring constants C _ges by biasing the strong director spring 18 in such a way it can be suppressed that now only the individual spring components C ₁ and C ₂ assigned to the two springs 18 and 19 become effective one after the other. So while with a pure series connection of the two springs 18 and 19, as shown in FIGS. 2 and 3, the switching point is determined by the stroke h and the spring constant C _{2 of} the strong spring 18, the switching point according to FIG. 4 largely determined by the bias of the strong spring 18. However, this in turn extends the range of application of the pressure switch according to the invention extraordinarily.

Claims (5)

Patent claims: 1. Pressure-dependent electrical switch with at least one contact spring protruding between the associated pair of contacts, which can be controlled by an organ that can be influenced from the outside via a tongue which is under the action of a spring mechanism as well as under the action of at least two mutually associated directional springs Directional spring has a strong spring force and the other, additional directional spring has only a weak spring force, characterized in that both directional springs (18, 19) are connected in series and the stroke (H, K) of the weaker directional spring (19) is limited. 2. Switch according to claim 1, characterized in that preferably between the two helical directional springs (18, 19) have an abutment on both sides, for example a washer (21), an intermediate piece (26) or the like having a collar (28) is arranged. 3. Switch according to claim 1 and / or 2, characterized in that the hub (H, h) of the weaker directional spring (19) by at least one spacer, for example a pin (23, 31) projecting into the interior of the spring (19) , a sleeve or the like surrounding the spring, which in its end position rests against the opposite end face (24) of the abutment (21, 26). 4. Switch according to one or more of the preceding claims 1 to 3, characterized in that that the stroke of the stronger directional spring (18) is limited. 5. Switch according to claim 5, characterized in that the stronger directional spring (18) of a sleeve (22) or the like, on the outer edge (27) of which a radially inwardly protruding, the abutment (26) engaging behind the collar (29) is arranged. 1 sheet of drawings 809 629/1156 10.68 © Bundesdruckerei Berlin