DE443698C - Multiple switch for low current measurements - Google Patents

Description

GERMAN EMPIRE

Library
Ind. Self-dom

ISSUED ON
May 5, 1927

REICH PATENT OFFICE

PATENT LETTERING

- JVr 443 698 CLASS 21 c GROUP 39

(Ü9198 VIIIl ₂

«Ö · Alexis Ulitovsky in Leningrad.
Multiple clialter for weak electronic measurements.

Patented in the German Empire on March 7, 1926.

When switching over the individual electrical measuring instruments to different line branches with measuring devices such. B. Temperature meters. Steam gauges, gas detectors, etc., it is very important that the various contact points have the same properties, which is difficult to achieve.

With the currents of a few milliamperes, which are used in such measurements has to do, but the slightest unevenness of the contacts results in significant errors in the specifications of the measuring instruments.

According to the present invention, these excess margins can be completely eliminated and the voγ

Horizontal changeover switches with full safety for measuring the smallest currents \ -er be turned.

The essence of the invention now consists in the following.

With each switch z. B. always stay on four contacts and must therefore constant pressure must be assured in four points. This is achieved by

ίο that there are three pins on the relevant contacts be pressed, which form the tips of a triangle. The fourth point is geometric center of gravity of this triangle, on which the whole pressure of a spiral spring is exercised and transferred to the triangle points. ...

Thus, the total pressure in the center of gravity of the triangle is distributed completely evenly and unchanged at any position of the triangle's tip points, whereby the resistance in the contact points of the contacts remains the same with each switchover.
"The drawing shows an embodiment of the present invention, namely Fig. 1 and 2 show the changeover switch schematically, Fig. 3 and 4 the external view from the front and rear, Fig. 5 the front view with the cover removed and Fig. 6 a cross section after AB the

Fig. S- ".... 1

A rigid triangular plate α has three iso- '

fastened pins b, c and ei with attached!

rounded tips (Fig. 1 and 2). I The pins form the tips of the triangle, point 0 'its geometric center of gravity. The points h, c and d are arranged in such a way that each of them lies on a different circle with the common center 0.

A number of contact plates I are arranged at the circle of point b , the contact ring II is arranged at the circle of point C , while a number of contact plates III are again arranged at the circle of point d. The pin b is conductively connected to the pin c and the pin d to the pin 0 , the latter being under the action of the spring 14.

It is practically almost impossible to make all contact plates I and III completely identical to one another. Regardless of this, in the present embodiment the reactive force remains the same as the total pressure at point 0 , and its distribution over the three points b, c and d of the triangle α remains completely the same for every position of the triangle despite the possibly significantly unequal height of the contact plates for each branch or each meter switched on in the same.

As already mentioned, FIGS. 3 'to 6 show an embodiment of such a multiple switch for ten branches. The cover ι S has an opening ιό secured with glass (Fig. 3) and a centrally arranged rotary knob ij. The rotary knob adjusts the triangle σ, which is under the pressure of the spring 14, by means of a driving pin r8 (Fig. 6); the contact plates I or III and the contact ring II have contact bolts with nuts on the lower side of the switch box (Fig. 4).

From the schematic drawing of the = Fig. 1 and 2 it can be seen that the point ο connected to the - (- terminal of the electric knife is connected to the branch contact 11I ₃ by the line od and the pin d , while the terminal with the terminal The contact ring II connected to the knife is connected by the line cb and the pins c and b to the branch contacts I _{3 of the} same branch to be measured, and the relevant number 3 appears in the opening 16 of the cover.

To secure the position of the changeover switch when setting to each branch concerned is the contact ring JI with recesses Γ9 according to the contact plate. I and III provided.

The entire switch is covered by the cover 15 in a dust-tight and waterproof manner.

Claims (1)

Claim: Multiple changeover switch for low current measurements, characterized in that it consists of a triangle, the tips of which point to contacts of three groups ; are based, which are based on three concentricu, the geometric center of gravity of the triangle circumscribed circles He- - gen, while the vow point of the triangle forms the fourth contact. For this purpose ι sheet of drawings.