DE410250C - Arrangement for small overcurrent switches in the form of oil switches with thermal release - Google Patents

Description

GERMAN EMPIRE

ISSUED
FEBRUARY 23, 1925

REICH PATENT OFFICE

PATENT LETTERING

CLASS 21c GROUP

VIIII2

Voigt & Haeffner Akt-Ges. in Frankfurt a. M. *).

Patented in the German Empire on May 10, 1924.

The innovation is intended for small oil switches that are used as circuit breakers for motors and the like, especially if they are to be used for motors that start under heavy overload, short-circuit motors and the like. For this purpose, the bushings carrying the contacts are designed as porcelain tubes with an opening at the bottom and a hot wire is fitted in them,

ίο which is also used to conduct electricity to the upper one Terminal is used. This ensures that on the one hand the otherwise necessary overcurrent relays in the absence of any and the space requirement is greatly reduced, on the other hand through the lower openings oil into the Porcelain tube can enter and has a cooling effect on the hot wire, i.e. the duration of the release is significantly reduced in the case of low overload, while in the event of severe overload or short circuit by heating the oil present in the porcelain tube, the triggering is accelerated.

In the drawing, α the lid of the oil-switch, the b with the interposition of the insulation is used in the implementation c. as d is the hot wire, which is attached to the contact on the one hand, and is connected to the lever on the other hand, which causes the trigger by interruption at i. Openings k are present on the contact. / is a horseshoe-shaped iron surrounding the bushing c on which

*) The patent seeker stated as the inventor:

Paul Brinkmann in Frankfurt a. M.

the armature / ra for the short circuit of the hot wire through the contact device is opposite at η. As is apparent from the drawing, * -tritr through the openings of the implementation c k oil into the interior so that the hot wire d is partly located in the oil and accordingly dissipates its heat in a certain way, is thus cooled. If there is a slight overcurrent, then so

ίο the hot wire ^ will expand and trigger the switch by means of the lever h by interrupting at i.

There is also a magnet I on the bushing. If there is a very strong increase in the current as a result of a short circuit, it will attract its armature m and thereby connect a circuit of very low resistance in parallel with the hot wire, so that the hot wire closes

ao strong currents cannot melt through. The attachment of this short-circuit device at η under oil, which causes a slight extinction of the sparks occurring there, and the attachment of the contact

»5 clock device for interrupting a zero voltage coil at / in air guarantees safe operation of the switch in all in Question coming cases.

Claims (3)

Patent Claims: 1. Arrangement for small overcurrent switches in the form of oil switches with thermal release, characterized in that the contacts carrying Bushings penetrated by the hot wire instead of the bushing bolts are. 2. Arrangement according to claim 1, characterized in that the porcelain bushings are provided with openings at the bottom through which the switch oil enters the Pipe climbs into it. 3. Arrangement according to claim 1 and 2, characterized in that the thermal Relay is provided with a magnetic +5 short-circuit device that with a very strong increase in the current strength closes and so relieves the hot wire, the contact device for a possible tripping due to the interruption of a zero voltage coil arranged above the oil he follows.