DE1172775B - Electromagnetic changeover switch with one-sided rest position - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school KL: HOIh

German KL: 21g-4/01

Number: 1 172 775

File number: W 32422 VIII c / 21 g

Filing date: June 14, 1962

Opening day: June 25, 1964

The invention relates to an electromagnetic changeover switch with a one-sided rest position, in particular of the type of melted-down reed switch or reed relay.

This type of switch usually consists of a hermetically sealed piston, which is supported by a Control coil is surrounded and which encloses a movable ferromagnetic tongue spring, which partially with a second, mostly rigid ferromagnetic contact piece serving as an outer contact piece The tongue overlaps and is separated from it by a narrow gap. When the control coil is energized, a magnetic control flux is formed in the longitudinal direction of the two tongues and in the intermediate one Gap and causes the overlapping ends of the same to make contact. if the device is used as a changeover switch with one-sided rest position, the movable tongue spring becomes normally pressed against a normally closed contact part, while the other tongue is a normally open contact side Forms contact part that only engages when the control coil is energized.

One of the main advantages of this switch is its simplicity; but its distribution largely depends on being amenable to mass production processes. Is detrimental to its usability the problem of counteracting the movable tongue spring with a constant, predetermined mechanical force to press the normally closed contact part. The elastic properties of the tongue or any Springs which press on the tongue have been found to vary considerably from switch to switch. This problem is accompanied by manufacturing difficulties in alignment and in relation on the distances between the various elements arise, especially in the case of higher-quality forms of a melted tongue switch.

It has also been found that under certain conditions there is a tendency that between open Contact parts arc discharges continue to burn when switched under high voltage will, so there are large potential differences between the tongue and the working or break contact part.

Some of these disadvantages can be avoided if a conductive permanent magnet is used as the normally closed contact part. It has been found, however, that the flux produced by the permanent magnet of devices of the previous type tends to interfere with the flux produced by the signal coil and thereby affect the general operation of the device
unilateral rest position

Applicant:

Western Electric Company Incorporated,

New York, N.Y. (V. St. A.)

Representative:

Dipl.-Ing. H. Fecht, patent attorney,

Wiesbaden, Hohenlohestr. 21

Named as inventor:
Walter Breckenridge Ellwood,
New York, NY (V. St. A.)

Claimed priority:

V. St. v. America August 3, 1961 (129 130)

pregnant. Furthermore, the flux of the signal coil tends to magnetize the permanent magnet to change.

It is an object of the invention to provide the structure of melted-down reed switches Simplify and facilitate their manufacture, in particular a predetermined and easily adjustable Contact pressure between the tongue spring and the normally closed contact piece of a tongue switch without disturbing the flux produced by the signal coil.

This task is performed with an electromagnetic changeover switch with a one-sided rest position of two outer contact pieces, one of which carries a rod-shaped permanent magnet, which in one are arranged at a certain distance from one another, and a non-preloaded changeover contact tongue spring, whose free end protruding into the space between the contact pieces is normally leans against the bar magnet (break contact) while it is under the influence of one of an excitation coil generated magnetic flux is attracted by the other contact piece (working contact), according to the invention solved in that the magnetic axis of the bar magnet essentially to the direction of the magnetic control flux in the working air gap is perpendicular and essentially in a perpendicular to the swivel plane of the tongue spring plane, so that that of the bar magnet

409 627/284

3 4

The permanent magnet is used for the flux originating essentially perpendicular to the electrical type of switch tric fields is due to a between only to generate a polarized working tongue spring and opposite contact piece wisely, i.e. for a completely different purpose, prevailing tension occur. The invention is based on one in the drawing

The flux of the permanent magnet is thus in detail in the embodiment shown in FIG Angle to the control flow so that no corn letters; it shows

component of the magnetic flux an additive or subtractive F i g. 1 a longitudinal section through the execution

tive effect on the tax flow. The switch is example and

therefore magnetically neutral, and its response is FIGS. 2a and 2b sections along line 2-2 of FIG

regardless of the direction of control flow. Um- io F i g. 1 when the normally open contact is closed or when the contact is closed, the control flux can change the magnetic self-contact of the exemplary embodiment, shafts of the permanent magnets of the normally closed contact - it will now be discussed in FIG. There is

partly not change. a melted reed switch 10 is shown,

Since most of the return flow of the permanent a hermetically sealed glass bulb 11 nenten magnet essentially perpendicular to the 15, in which at one end two outer conelectric Field between the tongue spring and the tact pieces 12 and 13 are arranged. At the other Working or the break contact is, a tongue spring 14 is so beSpalt in the end of the piston existing gas ions and free electrons that the free end of the tongue spring is strengthened prevented from being directly or in a straight line between the contact pieces 12 and 13 into it Tongue spring and one of the outer contacts to 20 stretches and an overlap area with these move as the magnetic field and current forms in the gap. A control coil 15 surrounds the glass bulb are crossed so that the formation of an arc discharge and controls the contact of the tongue spring 14 with the If switching takes place under load, contact pieces 12 and 13 are prevented.

will. In addition, the permanent magnet exercises as a result of the contact piece 12 carries a permanent magnet

its special orientation via two magnetic 25 th 17, the one with the magnetically neutral point on Column on the tongue spring a magnetic force contact piece is attached and its magnetic which therefore decreases sharply with the distance. Axis perpendicular to both the coil axis and As a result, the permanent magnet geauf to the axis of the between the contact pieces the tongue spring exerted little force. formed gap. The magnet serves as a resting when it is in contact with the normally open contact part. 30 contact for the tongues leaning against this On the other hand, however, it is in contact with the pearl 14. In the non-actuated, intestinal magnet in FIG. 1 of the normally closed contact is, a current flows over when the switch is in the set state magnetic force on the tongue spring so great that the tongue 14, the magnet 17 and the Kontaktein good contact pressure is ensured and a piece 12.

due closing of the normally open contact prevents 35 The contact piece 13 and the tongue spring 14 bewird. It is expediently provided that they are made of soft magnetic material. If the Tongue, the contact pieces and the magnet in a signal coil 15 is energized, a magnetic flows gas-filled glass bulbs are melted down. Control flow via the tongue spring 14 and the ferro-

There is also a type of switch known in which the magnetic contact piece 13, as shown by the generation of a control flux direction-dependent switching 40 path H ₁ . This control flux has the function of a permanent magnet with one or both of the magnetic force of attraction between the tongue of the outer spring 14 made of ferromagnetic material and the contact piece 13. This force standing contact pieces is coupled so that in overcomes the force of attraction of the permanent effect a magnetic rectifier arrangement for magnets 17, so that the tongue spring 14 is formed by the condensation control flux. For this purpose, a 45 clock piece 13 is attracted and provided between the two cases that both outer contact pieces, a contact takes place (working contact). When the signal current ceases in a position parallel to the direction of control flow, the tongue 14 jumps both arranged approximately in the middle of its length due to its elastic restoring force and cranked so that an enlarged gap area is due to the field of the permanent magnet 17 . In this area, the gap is magnetically 50 sem back and is arranged by the magnetic bridging permanent bar magnet, pulling force in firm electrical contact with its poles resting on the contact pieces. By this and thus with the contact piece 12, a narrowing of the mutual distance of the (normally closed contact) is held.

two outer contact pieces on the input The magnet 17 consists of hard magnetic

At the end facing side, the path of the flux originating from the permeable material, which closes a path with high magnetic permanent magnets, represents resistance for the flux H ₁ , so that a so that the contact pieces along this flux path goes over the conductor 12 with a very low flux , also in a saturated state. The magnetic control if this conductor made of magnetic material flow can therefore only via the contact piece that is available.

Achieve tongue spring in which the permanent 60 F i g. 2 a shows the position of the tongue spring 14 in the flux originating from the magnet in the opposite actuated state, ie when it has a magnetic direction. As an alternative to this, control flow can be provided through the tongue spring and the ferromagnetic contact piece 13 that flows in a rod-shaped permanent magnet. In FIG. 2 a allele or antiparallel to the control flow direction on the signal flow H _{1 is shown} by crosses, ie, contact pieces are attached, whereby the between 65 he emerges from the plane of the drawing upwards. The part of each con-polarity of the permanent magnet 17 which lies at the poles of the bar magnet results in a clock piece in the corresponding magnetic permanent magnetic flux path H ₂ . It should be noted that the state of saturation is brought about. With this known- the magnetic axis and thus the flux path H.,

5 6

of the magnet 17 at right angles to the path H _{1 of} the after the fusion is formed and on

Control flow lies. It is therefore no significant room temperature has cooled down, the sheet is de-

Flux component of the permanent magnet present, removes.

which has an additive or subtractive effect on the building is then between the poles of a Can have control flow. As a result, the 5 electromagnets pushed speaks of a high magne device in the same way on a river, the table field of z. B. produce 25,000 Gauss is perpendicular to the plane of the drawing and can go down. The axis of the permanent magnet is aligned is as if held on a river of the same orientation allele to the field. The permanent magnet 17 tion, but in the opposite direction. The latter is made of a hard magnetic material shown in Fig. 2a. The mode of operation of the circuit with high coercive force, while the contact piece 13 ters 10 is therefore independent of the direction of the low coercivity made of soft magnetic material the coil 15 flowing control current. It is there by virtue of its existence. When the magnetic field is removed In contrast to similar devices up to now, the permanent magnet 17 retains a strong one prior art magnetically neutral, and the establishment of permanent magnetization while the contact of the F i g. 1 speaks in the same way to one of 15 pieces 13 remains unmagnetized. The permanent left to the right directed control flow as on a magnet 17 preferably consists of a warm von right-to-left flow of control. treated alloy of 77% platinum and 23% carbon

2b shows the position of the tongue 14 in its bait, while the contact piece 13 and the tongue 14 normal or inoperative condition. One sees, for example, a heat-treated alloy that the flux of the magnet 17 in the tongue 14 over 20 49% cobalt, 49% iron and 2% vanadium heart white magnetic column occurs, namely can be placed over a. If with miniature execution The north pole and a very small short magnet on the south pole of the permanent ring of the switch. It can be shown that the use of the contact may be desirable Body to produce magnet pieces 12 from two pieces, which act over the two gaps Tical force decreases much more strongly with the distance 25 one from the latter alloy to Einais a corresponding force that only melts one into the glass and the other from the rust gap works. Therefore, when the tongue 14 is in its free steel or feed wire, to a non-actuated Location is as shown in FIG. 2 s is shown to create magnetic carrier for the magnet, the magnet 17 exerts a smaller magnetic force.This may be necessary because it is difficult to do that on it, as if the force is only applied by a contact piece 12 to a very small magnet magnetic gap acts. to fix its neutral point.

Under certain circumstances, after magnetization, the tongue is in the conditions a potential difference between the gap between the magnet 17 and the working tongue 14 and the contact piece 13, contact part of the contact piece 13 is used. When the tongue from the contact piece 13 to the magnet 35 tube structure is merged with the protruding tongue with th 17, as shown in Fig. 2b, the open end down into the heating coil or vice versa. The elec- tric caused by this. While forming gas in the open tric field £ has the tendency to blow gas molecules in the end of the piston, the second gap between the contact parts is ionized, fusing at the tongue end of the piston 11, where in the absence of the flow H ₂ a 40 with itself the tongue in a completely un-arc discharge. However, because the stressed condition is located. FIuBH _{2 is} perpendicular to the electric field / s. The above manufacturing process is advantageous for several reasons in the gap, the magnetic field and the current. The magnet 17 is first magnetically crossed, as a result of which the ions are forced to be tized after following the cycloid or trochoidal path with the contact piece 12, which welds and the external contact end of the piston is at right angles to the electrical as well as to the melted. Which cherish during welding and magnetic field. As a result, the heat generated by the melting process can prevent the rich ions and free electrons from directly traversing the gap, which no longer affects the magnetization of the magnet, with undesired results. Furthermore, glow or arc discharges cannot accumulate on the magnet 17 in their duration, no magnetic dirt can accumulate before it subsides, if not completely prevented. Here- is magnetized. A magnetic blow-out effect arises from the not yet magnetized, ahn magnets 17 can, before it is magnetized, borrowed as with large circuit breakers. Dirt particles can be easily removed by compressed air

It is now the manufacturing process for each one. Finally, the normally closed contact pressure of the

fused reed switch of FIG. 1 explained. 55 tongue on the magnet 17 easily within wide limits

The piston 11 initially has the shape of a glass- can be adjusted simply by changing the thickness

tube that is open at both ends. The contact of the magnetic field during the magnetization

Pieces 12 and 13 are changed into a device.

Bracht that they are slightly inclined and at the end of the magnet It should be noted that only a mechanical Abin Keeps contact. The end of the magnet is then in the 60 stand, the - if the contact end an open end of the glass tube is inserted, which is fused into the flask - adhered to suitable heating coil is held to the must, namely the size of the gap between Perform melting. A chisel-shaped the magnet 17 and the contact piece 13. If Sheet metal of a predetermined thickness is reduced between the rest - this fusion is carried out contact-side contact piece 17 and the working 65 the accompanying heat the pressure on the distance contact-side Contact piece 13 pushed to the plate that defines the gap, so that when straightening out Keeping the distance and alignment tight, pulling the sheet metal no moving the magnet while the end of the tube is fused. or the contact piece 13 occurs.

As stated above, the tongue 14 is melted in the piston 11 in the unstressed state. This is important because it is for this reason that the normally closed contact pressure between the tongue and the Magnet does not depend on the elastic properties of the tongue.

In summary, it can be stated that the attachment of a permanent magnet 17, its magnetic axis is perpendicular to the path of the control flux, advantageous for pretensioning the tongue 14 is because it improves the functioning of the device and because it improves the manufacture of the device relieved. A particular advantage is the control flow direction-independent response of the device.

Claims (5)

Patent claims: 1. Electromagnetically controlled changeover contact with one-sided rest position, consisting of two outer contact pieces, one of which carries a rod-shaped permanent magnet that is inserted into are arranged at a certain distance from one another, and a non-preloaded changeover contact tongue spring, whose free end protruding into the space between the contact pieces is normally on the bar magnet leans (normally closed) while it is under the influence of one of an excitation coil generated magnetic flux is attracted by the other contact piece (working contact), thereby characterized in that the magnetic axis of the bar magnet is substantially to the direction of the magnetic control flux in the Working air gap is perpendicular and in wesentliehen in a perpendicular to the pivot plane of the Tongue spring standing plane runs, so that the flux originating from the bar magnet is essentially is perpendicular to electrical fields that result from a between the tongue spring and opposite contact piece occur voltage prevailing. 2. Switching device according to claim 1, characterized in that the tongue, the contact pieces and the magnet is fused into a gas-filled glass bulb. 3. Device according to claim 1 or 2, characterized in that the contact piece lying on the working side has the shape of an elongated one Has rod which is arranged substantially parallel to the tongue spring, and that the magnetic control flux substantially axially to both the contact piece and the tongue spring runs. 4. Device according to claim 1, 2 or 3, characterized in that the bar magnet bearing contact piece is formed by a conductive non-magnetic carrier attached to the Side of the magnet midway between the poles of the magnet, d. H. at its »neutral Point «, is attached. 5. Device according to claim 1, 2 or 3, characterized in that the bar magnet has a Forms part of an elongated conductive support rod and forms the neutral point of the permanent magnet of the holding rod essentially parallel axially with the free end of the tongue spring is aligned. Considered publications:
German Auslegeschrift No. 1 033 762;
U.S. Patent No. 2,245,391. 1 sheet of drawings 409 627/284 6.64 © Bundesdruckerei Berlin