US728821A - Heater cut-out for electric lamps. - Google Patents

Description

No. 728,821. PATENTED MAY 19, 1903. A. J. WURTS. HEATER GUT-OUT FOR ELECTRIC LAMPS.

APPLICATION FILED MAR. 14. 1901. RENEWED we. 4, 1902. NO MODEL.

Fig. 71

75 WITNESSES: a INVENTOR A TOR/V5 r.

UNiTED STATES Patented May 19, 1903.

PATENT Genres.

ALEXANDER JAY WURTS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO GEORGE VVES'IINGHOUSE, OF PI'ITSBURG, PENNSYLVANIA.

HEATER CUT-OUT FOR ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 728,821, dated May 19, 1903;

Application filed March 14, 1901. Renewed August 4:, 1902. serial No. 118,380. (No model.)

To all whom it may concern:

Beitknown that LALEXANDERJAYWURTS, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Heater Cut-Outs for Electrio Lamps, of which the following is a specification.

My invention relates to.electric lamps of the type in which the light-giving body or glower is a non-conductor when cold and is raised to conducting temperature by means of an electric heater located in proximity thereto.

My invention relates more particularly to devices employed for automatically opening the circuit of the electric heater when the glower becomes conductive and for automatically closing such circuit when the glower is not taking current either by reason of its being in a non-conducting state or by reason of its circuit being open.

The object of my invention is to provide a cut-out or circuit-interrupting device that shall be actuated. by gravity to close the circuit and by magnetism to open it, that shall be effective and durable in operation, and that shall be substantially noiseless when used in lamps operated by alternating currents. In order to accomplish this object, I have devised a cutout the movable member of which has a single point of pivotal support and has its center of gravity below such point of support in all its operating positions.

In the accompanying drawings, Figure 1 is a view, partially in side elevation and partially in section, of one form of cut-out embodying my invention, the other members of the lamp and the circuits being diagrammatically indicated. Fig. 2 is a view, partially in plan and partially in section, of the movable member of the cut-out and its supporting-pivot shown in Fig. 1. Fig. 3, is a view, partially in section and partially in end elevation, of the cut-out shown in Fig. 1. Figs. 4 and 5 are detail views showing modified forms of support for the movable member of the cut-out.

Referring now to Figs. 1, 2, and 3, the glower 1, heater 2, and ballast 3 may have any wellknown and suitable construction and arrange- I ment, the glower and ballast being connected in series with each other and with a cut-out coil h'which has a core 5 projecting downwardly beyond the end of the coil and is supported, by means of a bracket 6, upon a suitable non-conducting base 7. The base 7 also supports two terminal posts-8, to which are respectively connected by any suitable bind ing means the terminals of the heater-circuit. Projecting inwardly through holes formed in the studs 8 are wires 9, preferably, though not necessarily, made of silver, the inner ends of which are bent downward, so as to form a V- shaped space between them, into which the movable member 10 of the cut-out drops by gravity action when the cut-out coil 4 is deenergized. The movable member 10, as shown, comprises a comparatively thin strip 11, on which are fitted three blocks 12, 13, and 14, the block 13 being preferably made of or coated with silver and so located as to engage the silver wires 9 to close the heatercircuit and the other collars or blocks being made of magnetizable material. The strip 11 may be of. steel or other suitable material and, as shown in Fig. 1, it is curved upwardly beyond the block 14 and is supported upon a pin 15, the ends of which are mounted in the arms of asuitable bracketor standard 16. In order to maintain the movable member 10 in a central position, the pin 15 may be tapered from both ends inwardly to the middle or otherwise formed, so as to present an approximately V=shaped formation in longitudinal section, the diameter of the pin at the apex'of the V being less than that of the hole 17 in the piece 11. The periphery of the opening 17 of the'piece 11 preferably has a knife-edge contour, so that it engages the pin 15 at a single point only. I have shown the piece 11 as provided with a cut or slit 18 at one side, so that the adjacent parts may be sprung away from each other in order to slip the device over the pin 15; but of course this feature might be omitted and the pin inserted through the opening 17 before seating its ends in the arms of the bracket 16. I have found it convenient to employ a steel strip 11, that is so thin as to present a sufficiently close approximation to with the source of current.

aknife-edg'e by merely cutting the hole 17 therein. This feature as well as certain of the others are, however,.subject to variations, all of which it would be impracticable to illustrate.

In Figs. l and 5 I have shown one modification in which the supporting-pin l5 for the movable member of the cut-out is a wire the ends of which are inserted in slots or sockets 19 in the arms of the bracket 16 and clamped in position by upsetting the adjacent metal of the bracket-arms. Between the two bracket-arms the wire is shown as bent into a V shape. This form is illustrated merely to indicate a simple and inexpensive variation from what is shown in the preceding figures without any intention of excluding from the scope of the invention any other forms of pivotal support for the armature that might be employed to permit freedom of movement under the actions of magnetism and gravity and at the same time permitlateral displacement along the pivot.

In operation the current first traverses the heater 2, the stationary contact-terminals 8 9, the bridging member 10, and the wires which connect these devices with each other and As soon as the glower 1 is heated to conducting temperature current flows through it, the ballast device 3, and magnet-coil 4, and the magnetic field produced by the latter lifts the armature 10 from the contact-terminals 9 and holds it in this position so long as the glower remains conductive. When the lamp is operated by means of an alternating current, the alternations tend to produce vibrations of the armature and a resulting humming noise that is objectionable. As here shown, however, the armature is so constructed and supported that its center of gravity is always below its single point of support, and consequently gravity acts throughout each alternation to hold the armature upon its support. The chattering or humming noise which ordinarily results from the intermittent pull of lowfrequency currents is thus avoided.

As I have already stated, my inventionis susceptible of embodiment in apparatus that differs from what is shown in the drawings as regards form, dimensions, and relative location of parts without modifying the mode of operation or result. I therefore do not intend to limit myinvention except in so far as limitations are imposed by the prior art and expressed in the claims.

I claim as my invention- 1. Ina heater cut-out for electric lamps, the combination with a cut-out coil, of adjacent, converging heater-terminals and a cooperating pivoted oontact-terminal having a knife-edge support and operated in one direction by the magnet and in the other direction by gravity and having its center of gravity below its point of support.

2. In a cut-out, the combination with an electromagnet an armature therefor serving as the movable member of the cut-out, converging contact-terminals and means for pivotally supporting the movable member above said terminals at a single point and with its center of gravity below said point.

3. In a heater cut-out for electric lamps, the combination with an actuating-magnet, of stationary contact-terminals, an armature serving to bridge said terminals when the magnet is deenergized and means for pivotally supporting the armature at asingle point.

at. In a heater cut-out for electric lamps, the combination with an actuating-magnet, of heater circuit-terminals and an armature for making and breaking the circuit at said terminals, said armature being pivotallysupported at a single point and having its center of gravity below the point of support.

5. In a heater cut-out for electric lamps, the combination with an actuating-magnet, converging heater circuit-terminals, and an armature having a pivotal support above said terminals and its center of gravity below said support in all of its operative positions, said armature being moved by magnetism away from said circuit-terminals and by gravity into engagement therewith.

6. In a heater cut-out for electric lamps, the combination with an actuating-magnet, of stationary heater-terminals, an armature for making and breaking the circuit at said terminals and a support upon which said armature is pivotally mounted by means of a knife-edge bearing.

7. In a heater cut-out for electric lamps, the combination with an actuating-magnet, of heater circuit-terminals and a combined armature and cut-out member havingaknifeedge hearing at a single point and having its center of gravity below said point of support in all its operating positions.

In testimony whereof I have hereunto subscribed my name this 11th day of March, 1901.

ALEXANDER JAY WURTS. Witnesses:

H. A. ORooKs, D. W. CRooKs.

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