US685488A - Heater cut-out for electric lamps. - Google Patents

Description

' Patented Oct. 29. I90l. H. N. POTTER.

HEATER CUT-OUT FOR ELECTRIC LAMPS.

.(Application filed Aug. 15, 1900. Renewed Sep(:. 6, 1901.)

(No Model.)

Fig. 1.

WITNESSES INVENTOR B l A'TTdm/Er.

m: norms PETERS o0. PHOTO-Undo" WASHINGYONA 0.6.

UN lTE- STATES PATENT OFFICE.

HENRY NOEL POTTER, OF HALENSEE, GERMANY, ASSIGNOR TO GEORGE XVESTINGHOUSE, OF PITTSBURG, PENNSYLVANIA;

SPECIFICATION forming as be Letters Patent No, 68 5,488, dated October 29, 1901.

Application filed August 15,1900. Renewed September 6, 1901. Serial No. 74,577. (No model.)

To all whom it may concern/.-

Be it known that I, HENRY NOEL POTTER, a citizen of the United States, residing at Halensee, in the Kingdom of Prussia and Empire of Germany, have invented a new and useful Improvement in Heater Cut-On ts for Electric Lamps, of which the following is a specifical'lOlL I My invention relates to electric lamps of the type in which the illuminating body or glower is a conductor only when hot; and it has particular reference to the means for eutting out of circuit the heaters employed for raising the temperature of the glowers in such lamps to the conducting-point.

The object of my invention is to provide an electromagnetic heater cut-out which will be operative under the action of a comparatively small percentage of the glower-current without unduly increasing either the size of the cut-out coil or the expense of its manufacture and at the same time avoiding the injuries caused by excessive heat due to the consumption in the coil of an excessive quantity of energy. With these ends in view I have devised the means shown in the accompanying circuit supplying a plurality of lamps in seballasts, particularly the latter, since they are not capable of withstanding an excessive current-overload. In order to overcome the difficulties incident to such condition and operation, I propose to employ a sensitive heater cut-out which will serve to interrupt the heater-circuit before the glower takes sufficient current to render the combinedheate'r and glower current of the particularlamp thus operating dangerous to the lamps of the series already in operation. 1

Referring now particularlyto the drawings, the circuit 1 is supplied with energy either directly or through a transformer from a main circuit 2, fed by a constant-potential generator 2. Thelamps 3, of which ten are shown in Fig. 1, will obviously be designed individs ually for such voltage that the number con nected in series will be adapted to the voltage supplied to the circuit either directly or indirectly from the circuit 2. The glower 4 of each lamp is supplied with current through a ballast device 5 and is heated to conducting temperature bya suitable heater 6, as is usual in this class of lamps. The cut-out for the heater-circuit comprises a magnet-winding 7, a core 8 therefor, and a movable contact member 9, that normally rests in contact with a stationary contact-terminal 10 and is moved into contact with a second stationary contact-terminal 11 when the magnetis energized. The contact-terminal 10 is connected to one terminal of the heater 6 and the contact-terminal 11 to a suitable point intermediate the ends of the Winding 7. The two parts 12 and 13 of the winding 7, between which the terminal 11 is connected, may be considered as separate coils connected together or as parts of a single winding. One terminal of the winding 7 is connected through the ballast device 5 to one terminal of the glower.

cut-out. It will be readily seen that when the glower is raised to conducting temperature by means of the current traversing the heater current will flow through the entire coils '7, and by reason of the length and consequent resistance of such coil the amount of current will not be sufficient to endanger the otherlamps in this series,but the small amount of current is sufficient to lift the member 9 into engagement with the stationary contactterminal 11, and when brought to that position the part 12 of the winding 7 will be shortcircuited.

It has been found in practice to be feasible The other terminal of the winding is connected to the movable member 9 of the to employ a magnetic cut-out of the usual type which will interrupt the heater-circuit upon the passage of one-half the full glowercurrent and which will not become unduly heated nor be extremely wasteful of energy when traversed by the entire current of the glower; but an attempt to employ a cut-out which will interrupt the heater-circuit when traversed by a small percentage, even as high as twenty-five per cent. of the normal glowercurrent involves difficulties on account of the size of the coil necessarily employed and the consequent expense of manufacture and the heating in use. With my present arrangement the heater-circuit is interrupted before the glower takes sufficient current to render the combined heater and glower current dangerous to other lamps in the series, and the short-circuiting of the part of the magnetwinding leaves only sufficient winding in circuit to maintain the heater-circuit in open condition.

My invention is not necessarily limited to use in connection with lamps operated in series in a constant-potential circuit, and I therefore desire it to be understood that variations in this respect, as well as in others, may be made without departing from the invention.

I claim as my invention- 1. In an electric lamp of the type described, the combination with a glower and a heater therefor, of a heater cut-out having two coils primarily connected in series with the glower and having means for cutting out one of said coils after the heater is cut out.

2. In an electric lamp of the type described, the combination with'a glower and a heater therefor, of a heater cut-out comprising two coils connected to form a single winding for breaking the heater-circuit and means for short-circuiting one of said coils after the heater-circuit is broken.

3. In a constant-potential electric circuit, a plurality of electric lamps of the type described connected inseries each of which has a heater cut-out comprising a magnet and means for short-circuiting a part of said winding immediately after the heater-circuit is interrupted.

4. In a constant-potential electric circuit, a plurality of lamps connected in series each of which has a glower and heater and a heater cut-out comprising an actuating-magnet, a movable member and two cooperating contact-terminals connected respectively to one heater-terminaland to an intermediate point in the magnet-winding, whereby the entire magnet-windingis utilized to break the heatercircuit and a portion of the same is immediately thereafter short-circuited.

In testimony whereof I have hereunto subscribed my name this 31st day of July, 1900.

HENRY NOEL POTTER.

Witnesses:

HENRY HASPER, WILLIAM MAYNER.

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