DE206249C - - Google Patents

Description

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IMPERIAL

PATENT OFFICE.

Patent specification

- ■ ΛΙ206249 - CLASS 21 c. GROUP

GEORG SANDER in OSNABRÜCK.

Patented in the German Empire on November 8, 1907.

A device is known according to which one on the shaft of one of an electric motor and an auxiliary machine of an existing machine set arranged centrifugal governor when the speed of the wave drops below a certain amount a circuit is created closes, which contains an automatic off switch for one machine and so on puts the machine set out of action. It

ίο is also no longer new, engines against Damage caused by excessive speed with the help of one on their axis arranged to protect their operating current interrupting centrifugal governor.

In contrast, the invention consists in that in the circuits one of the motor monitoring, electromagnetic switch, two contact devices connected in series one operated by the engine starter lever and one Current circuit device influenced by a centrifugal governor located on the motor axis. The current circuit for the electromagnetic switch is now overloaded when starting the Engine prepared by the governor at one point and by the starter lever only established when a certain starter contact is reached at a second point, in normal operation of the engine, on the other hand, prepared by the starter lever at one point and by the governor only established at a second point when the motor is overloaded.

The invention is shown schematically in the drawing.

The motor shaft α is extended at its end and carries a centrifugal governor b, which moves a sleeve d on the motor shaft extension c. This is at your ί

Provide the free end with a metal plate e insulated from it. In front of this metal plate there is a fixed, adjustable pair of brushes consisting of carbon f and holder g , which is connected to the electrical line h, h ¹ . The circuit of the latter can now be closed or interrupted at this point by the regulator sleeve plate e, and at a second point by the manually moved starter lever of the starter i. An automatic, electromagnetic switch k is built into the line h, k ¹ , which interrupts the motor supply lines I , which are also protected by fuses s, in the event of a current connection in the same. m collector brush is η, the collector, 0 of the armature of the motor, p represents the field winding and r, q, r ^1, the associated lines. The starter is i provided with a contact rail t, which during the movement of the starting lever from right to left, ie when starting the engine, at a certain point the starter period comes into conductive contact with the starter lever and thus closes the circuit h, h ¹ at this point.

The device works in the following way, namely 1. when starting the engine and 2. for the engine in operation.

i. If the motor is switched on at a certain overload and therefore does not start when the starting lever is moved to the second or possibly third contact, the regulator sleeve plate e keeps the circuit h, h ^{1 closed} at e, f . As soon as the starting lever is brought to the fourth contact as shown in the figure, current flows through the contact bar t into the current-

circle h, h ^{1 of} the electromagnetic switch k ; this responds and interrupts the motor current lines I.

2. If the motor was so_loaded that it started on the first three starting contacts, the maximum switch circuit h, h ^{x was} interrupted in good time at e, f and, with the motor that is now in operation on the rail t, is completely after

ίο the left-hand starter lever held closed. If the number of revolutions falls below a certain minimum as a result of the motor being overloaded, the controller or its sleeve plate e at e, f establishes a current connection in the line h, h ¹ ; consequently, the electromagnetic switch k of the main line I comes into action and interrupts the flow of current to the motor.

Claims (1)

Patent claim: Device for protecting electric motors against overload, characterized in that two current connection devices, one influenced by a centrifugal regulator arranged on the motor axis (e, f) and one formed by the regulator lever of the starting resistor and a contact bar (t) arranged on the latter, are in this way in the Circuit (h, h ¹ ) of an electromagnetic switch (k) monitoring the engine are switched on, so that the circuit for the latter is prepared by the centrifugal governor at one point when the overloaded engine is started and by the starter lever when a certain starter contact is reached by touching the Contact bar (t) is made at a second point, during normal operation of the engine, on the other hand, prepared by the circuit breaker consisting of the starter lever and contact bar (t) at one point and made by the centrifugal governor at a second point when the motor is overloaded. 1 sheet of drawings.