US2044256A - Automatic flashing lamp - Google Patents

Description

June 16, 1936- P. A. NOTHSTINE AUTOMATIC FLASHING LAMP Filed July 18, 1927 Patented June 16, 1936 UNITED STATES PATENT OFFICE 2,044,256 AU'roMA'rIc FLASHING LAMP Paul A. Nothstine, Dayton, Ohio Application July 18, 1927, Serial No. 206,566 12 Claims. (01.176414) My invention relates to incandescent lamps, and more particularly to an intermittently operated or automatic flashing lamp. Intermittently illuminated or flashing lamps are quite commonly employed for advertising purposes, illuminated signs, signals, and the like. Ordinarily such lamps are controlled by a thermostatic switch or circuit breaker which may be common to a number of such lamps and located in the supply circuit, or in some instances individual thermostatic switches or circuit breakers are provided in the respective lamp sockets.

In the present instance the automatic circuit breaker or thermostatic switch is enclosed within the lamp bulb and controlled by either light or heat from the lamp filament, or by both. There is thus provided a unitary flasher lamp wherein the oxidization or burning of the switch or circuit breaker contact points is minimized, due to the fact that such contact and breaking takes place in a vacuum or in a body of non-conductive inert gas. By so minimizing the deterioration of the circuit breaker or thermal switch such element, although of small size and cheaply constructed, will outlast the life of the filament.

The thermal member is preferably, though not necessarily, a short flexible bi-metal arm, the preferred materials being phosphor bronze and invar, which is a nickel steel alloy sometimes known as Guillaume or Serves alloy having a substantially zero co-efiicient of expansion and contraction. The bi-metal thermal member may be blackened on one side and white on the other and thus caused to absorb the rays of light from 5 the filament upon the black side and thus induc ing a warping action. This absorption of light is but an indirect application of heat. In lieu of such indirect'heat or light influence the thermal member may be controlled by direct radia 40 tions of heat from the illuminating filament of a lamp, or by the heat of a heating coil associated therewith and connected in the lamp circuit in series withthe filament, which heating coil is intermittently short circuited or shunted by the closing of the thermal switch member. As an alternative construction the heater coil may be bridge across the filament terminals or in parallel in such manner that the warping or opening of the thermal switch under the influence of heat 5 generated by such coil will disconnect both the coil and the filament. Furthermore, such thermal switch member maybe arranged within the bulb to connect different filaments or portions of a divided filament alternately into the circuit. in order to give definition to the pulsations or alternating periods of illumination and obscurity magnetic means is preferably, though not necessarily employed to temporarily delay the alternation of the thermal switch element, causing it to momentarily hold in position until sufficient inherent tension has been accumulated to effect a quick snap or breakaway action.

In especially large lamps a resistance unit may be connected across the thermal switch to by-pass a fractional part of the voltage during the period of non-activity of the filament thus preventing a voltage drop to zero. By breaking the filament circuit in a vacuum or a body of inert gas it makes possible the flashing of large lamps which otherwise would be impracticable.

The object of the invention is to simplify the structure, as well as the means and mode of operation of intermittent or flashing incandescent lamps whereby they will .not only be cheapened in construction, but will be more eiilcient in use, positive in operation, uniform in action, of greater durability, capable of increased periods of operation, and unlikely to get out of repair.

A further object of the invention is to provide an automatic interrupter or flashing element incorporated in and forming a unitary part of an incandescent lamp or" commercial type.

A further object of the invention is to provide an intermittently operated switch or flasher the operation of which will be effected within a vacuum or body of inert gas, non-conducive to oxidization and thereby minimizing deterioration or burning of the contact points.

A further object of the invention is to provide means for temporarily retarding, the action of the thermal switch or intermittent flasher element by holding such element in its operative position by magnetic means until sumcient irlierent tension has been developed to effect a quick and forcible instantaneous break of the contact relation. 1

With the above primary and other incidental objects in view, as will more fully appear in the specification, the invention consists of the features of construction, the parts and combinations thereof, and the mode of operation, or their equivalents, as hereinafter described and set forth in the claims.

Referring to the accompanying drawing wherein is shown the preferred, but obviously not necessarily the only forms of embodiment of the invention, Fig. 1 is a side elevation of a commercial type of incandescent lamp in which the present invention has been embodied in a simplifled form. Fig. 2 is a similar view showing the thermal'switch or circuit breaker controlled by a heating coil connected in series with the filament. Fig. 3 illustrates a modification wherein the heating coil is connected in parallel with the filament. Fig. 4 is a detail view somewhat diagrammatic illustrating the application of the present circuit breaker to a divided or multiple filament, the portions of which are to be energized alternately. Fig. is a similar view of a modification of the thermal member arranged for control by direct heat radiation. Figs. 1a, 2a and 3a are schematic diagrams of the arrangements shown in the corresponding Figs. l, 2 and 3. Fig. 6 is an enlarged detail view of the detent magnet for the vibratory thermostatic arm.

Like parts are indicated by similar characters of reference throughout the several views. a Referring to the drawing l is the usual bulb of an incandescent lamp within which is the li- -luminating filament 2 supported upon the usual press 3. The current is supplied to the filament 2 through the usual lead. wires 4 and 5 embedded in the press and connected with the terminals upon the base 6 in the usual manner.

The bulbd is exhausted to afford a vacuum or is filled with an inert gas, such as nitrogen.

Enclosed within the bulb I is a thermostatic switch or circuit breaker 1. For convenience of mounting this circuit breaker or thermal switch I has been shown supported upon the press 3. It is to be understood, however, that it may be supported in any suitable or convenient manner. One end of the thermal arm I is connected with the lead wire 4 while the free end of such arm makes intermittent contact with a terminal 8 communicating with the filament 2. The thermal arm 1 thus completes the circuit between the lead 4 and the contact 8 thus supplying current to energize the illuminating filament 2. As the filament 2 becomes incandescent the heat generated thereby radiates to the thermal arm 1 causing this arm to warp and thereby break its contact with the filament terminal 8. As the contact is broken the circuit is interrupted and the filament de-energized. The source of heat being removed the arm I after a momentary interval returns to its original position as it cools and again makes contact with the terminal 8 to reestablish the circuit and again energize the filament. This alternating make and break action continues indefinitely during the operation of the lamp. The thermal arm I is preferably of bi-metal form. That is to say it consists of two thin strata of metals having different co-efiicients of expansion and contraction. The preferable materials are phosphor bronze and invar, which is a nickel steel alloy, having substantially a zero co-efilcient of expansion and contraction. Obviously, however, other materials may be employed. In lieu of depending upon direct heat radiation to eifect the warping action of the thermal arm I, one side of said -arm may be blackened and the other side whitened or made bright, whereby it will reflect the light rays, which are absorbed by the dark side. Such absorption of light rays, which is in fact, but an indirect application 01' heat will serve the same purpose of causing the warping or bending action of the thermal'arm l to make and break its engagement with the contact 8. In Fig. 2 is shown a modified construction wherein in lieu of depending upon the radiation of heat or light from the filament 2 a heater coil 9 is provided about the thermal arm I, which coil, in this instance, is connected in series with the filament 2 between the lead wire 4 and the filament terminal 8. This heater coil, however, affords such resistance that so long as it is in the circuit the filament 2 will not be energized as sufilcient current cannot fiow there through to cause it to become incandescent. However, during such period the fiow of current through the coil 9 serves to heat the thermal arm 1 suI ficiently to cause it to make contact with the terminal 8 and thereby shunt or short circuit the heater coil 9. The energizing current may then flow freely through the lead wire 4 and through the thermal arm 1 to the terminal 8 leading to the filament which will become incandescent. The current passing through the arm 1 instead of through the coil 9 allows the coil to cool, and as the temperature of the thermal arm 1 also decreases it will warp away from the terminal 8 and so break the direct path oi current and again bring the heater coil 9 into the circuit.

There is this difference noticed between the construction shown in Fig. l and that disclosed in Fig. 2, that whereas in Fig. 1 the heat influence upon the thermal arm or circuit breaker 1 causes such arm to open the circuit or break its connection with the contact 8, in Fig. 2 the influence of heat serves to close the contact between the arm I and terminal 8.

To give definition to the pulsations oi the thermal switch or circuit breaker and momentarily retard its action there is preferably, though not necessarily, employed a miniature bar or horseshoe magnet in which tends to attract and hold the free end of the vibratory arm I, which in this case is provided with a slight deposit ll of iron to form an armature. One pole of this magnet is preferably insulated to prevent electrical contact by providing a small stud or wafer H of insulating material which is engaged by the thermal arm to prevent direct electrical contact with such pole of the magnet while under the influence of its magnetic attraction. The opposite pole of the magnet may be connected with or comprise the filament terminal 8. In such case the thermal arm I will approach the pole of the magnet solely under the influence of heat until it comes within the range of magnetic attraction, whereupon the contact engagement will be sudden and forceful as the influence of the magnet is added to that of temperature or light tending to warp the arm 1. Upon decrease of the heat influence the free end of the thermal arm I will be momentarily held and its action retarded, while inherent tension is being accumulated due to temperature change. As the spring tension of the arm 1, due to change of temperature, increases sumciently to overcome the attraction of the magnetic pole the arm I will be released with a snap action aifording an instantaneous and complete break of contact. When the arm in its warping action due to temperature change approaches the opposite pole of the magnet the amass cool somewhat, whereupon it will return to its it breaks its contact to open the filament circuit it also: opens the circuit to the heater coil In other words the point of make and break oi the thermal arm 1 is between the heater coil and the lead wire 4. In this case the thermal arm 'I normally closes the circuit at lower temperature and opens it as the temperature increases; Normally the arm I will be in contact with the terminal 8' and so complete the circuit through the filament 2. The heater coil 9' being also connected with the filament will also receive suillcient current to cause it to heat the thermal arm I, whereupon the contact is broken bebetween said am and the terminal 8. This not only disconnects the filament 2, but it also disconnects the heater coil 8. As the temperature of the arm I and heater coil 8' decreases the arm will again return to contact with the terminal 8' to re-establish the circuit through the filament and at the same time through the heater coil. The magnetic regulator heretofore described may be employed with any one of the several forms of embodiment of the invention. While a double pole or horseshoe magnet is to be preferred single pole or bar magnets may be utilized. In such case the thermal arm will be retarded at only one end of the range of movement. However, the effect will be substantially the same.

As a further variation oi. the application of the invention there is shown in Fig. 4 a diagrammatic view in which the filament is divided into two sections i3 and H, by the attachment of the thermal arm I at a mid-length point. In this instance the warping of the thermal arm I, first in one direction and then in the other, serves to shunt or short-circuit first one portion and then the other of the filament. In its movement in one direction it engages the terminal I5 of the lead wire 4 and so eliminates from the circuit the portion 14 of the filament. Upon its reverse movement it will engage the terminal l6 associated with the lead wire 5 to thereby shunt or short-circuit the portion iii of such filament. Thus the portions of the filament are alternately energized. These filament portions may be of unequal extent or unequal character, thereby giving to the lamp an alternating or flashing effect, without however entirely destroying illumination during alternating intervals. Likewise, the filament portions l3 and Il may be of equal extent and like character, and thus be alternately i1- luminated after momentary intermediate periods oi simultaneous illumination, while the thermal arm is passing from one contact to the other. In the construction shown in Fig. 4 the thermal arm 1 is preferably controlled by the influence.

of light from the respective sections of the filament. To this end one side of the thermal arm is preferably blackened while the other side is whitened or polished. In Fig. 5 there is shown a similar construction wherein the thermal arm 1' is bent to arcuate form and thereby extends in very much closer relationship to one portion ll of the filament than to the opposite portion 13. Thus, whenever the portion ll of the filament is rendered lowly incandescent, the thermal arm will be subjected to an increase of temperature sufiicient to afford a warping efiect by which its contact with the terminal i5 is broken and engagement made with the terminal It to establish the circuit through the thermal arm and then through the portion ll of the filament. The filament portion l3 .being further removed from the arm will cause the thermal arm I to engagement with the terminal I! again establishing the circuit through the portion ll of the filament. The filament portion ll being closer to the thermal arm will cause it to be heated s sufiiciently to repeat its action.

The magnetic regulating means heretofore described may be applied to the form 01' device shown in Figs. 4 and 5 as well as to the other embodiments of the "invention. 10

From the above description it will be apparent that there is thus provided a construction oi the character described, possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modifil5 cation in its form, proportions and arrangement of parts. without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute, the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise the preferred form of several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described my invention, I claim:

1. A unitary flashing lamp including a bulb having a non-conducting chamber, a filament and an automatic circuit breaker both included in said chamber, circuit leads for continuously supplying current to the filament, said circuit breaker including a magnet cooperating with an electrothermal element carrying one of the contacts of the circuit breaker, said element within the bulb controlling the operation of the filament and in turn controlled thereby.

2. In a unitary flashing lamp, a bulb, a filament and a vibratory circuit breaker connected thereto both enclosed in said bulb, circuit leads for supplying current to the filament, said breaker including a movable heat responsive member to opcrate the circuit breaker to interrupt the current supply, and magnetic means spaced with respect to the filament for temporarily retarding the action of said breaker.

3. The combination of a lamp having a bulb and a filament in said bulb with a thermostatic control device connected in the filament circuit and a magnet all mounted in said bulb, thermally responsive means composed in part of magnetic material associated with said magnet and nor- 5 mally held in contact therewith by magnetic attraction but adapted to separate therefrom when the temperature of said device exceeds a predetermined value, said magnet and means being electrically interconnected with the filament 60 circuit.

4'. A lamp assembly including a lighting filament, electric circuit leads thereto, a thermostatic make and break switch in the filament circuit including a bimetallic element and a magnet, 66 a sealed lamp bulb in which said switch and filament are enclosed, said conductors extending from said element and said magnet to the exterior of said bulb for connecting said switch in an electric circuit, said conductors supporting 70 said switch in spaced relation to said bulb.

5. A unitary flashing lamp including a bulb,

a filament and an automatic circuit breaker both enclosed in said bulb, said circuit breaker including a thermal responsive electrical contact 76 element a heater coil to which the thermal contact member is responsive and a magnet having a magnetic core, leads for supplying current to the filament, said heater coil being permanently interconnected to the filament and aflording resistance alternately included in and excluded from the filament circuit by the fluctuations ot the thermal responsive contact member biased in at least one direction by said magnet.

6. In a flashing lamp, a bulb, a filament and a thermal responsive circuit breaker including a magnet enclosed in the bulb, said magnet being arranged in spaced relation with respect to the filament, electric circuit leads for supplying electric current to the filament, and a duofunctional heater and resistance element also enclosed in the bulb and included in and excluded from the filament circuit by the fluctuations of the thermal responsive circuit breaker, said duofunctional coil when in the circuit afiording resistance by which the lighting efifect oi the filament is subdued.

7. A unitary flashing lamp, including a bulb, a filament and a thermal responsive circuit breaker both enclosed within said bulb, said circuit breaker including a magnet arranged in spaced relation with respect to the filament, circuit leads for supplying current to said filament, and a heater coil for said circuit breaker also enclosed within said bulb and intermittently bridged across the leads in parallel relation with the filament, said filament being permanently connected in said circuit and heater coil being periodically included in and excluded from the circuit by the make and break operation of the circuit breaker under influence of said coil, said heater coil affording resistance in the circuit.

8. In a unitary flashing lamp, a filament, and an automatic circuit breaker controlled by influence of the filament current, a bulb enclos ing said filament and circuit breaker, conductor leads for supplying current to the filament, a shunt circuit opened and closed by the circuit breaker, and a magnet spaced from the filament tending to attract and hold said circuit breaker in operative position in opposition to the influence of the filament current.

9. A lamp comprising a bulb, a non-conducting medium in said bulb, a filament mounted in said bulb, conductors extending through the bulb and connected to the filament terminals for supplying energy thereto, and an automatic circuit breaker interconnected with one of the conductors, said circuit breaker including a thermostat responding to thermal conditions and a magnet mounted in spaced relation from the filament, but within the bulb, said magnet exerting a pull at least in one direction upon the thermostat tending to hold the circuit breaker in at least one position.

10. A unitary flashing lamp including a bulb, a filament, and an automatic circuit breaker, current leads for supplying current to the filament, said circuit breaker including a thermal responsive contact element, a magnet enclosed in the bulb but in spaced relation from the filament, a heater coil for the thermal responsive .contact element also enclosed within the bulb, the heater coil being permanently interconnected to at least a portion of the filament whereby the filament current flowing therethrough influences the thermal responsive contact element to closed condition to short circuit the heater coil and supply filament current to the filament through the thermal responsive member independently of the heater coil until under influence of decreasing temperature the thermal responsive contact member reacts to open condition.

11. A unitary flashing lamp including a bulb, a filament and an automatic circuit breaker, both included within said bulb, circuit leads for supplying current to said filament, said circuit breaker including a heater coil with a thermostat also included within said bulb, said circuit breaker including magnetic means exerting a pull in at least one direction upon the thermostatic means which operates in response to said heater coil to alternately open and close the supply circuit to both the heater coil and the filament. 12. A unitary flashing lamp including a bulb, a filament, and a thermal responsive circuit breaker including a resistance element and a magnet arranged in spaced relation with respect to the filament and enclosed in the bulb, leads for continuously supplying current to the filament, said thermal responsive circuit breaker being effective to decrease the flow of current through the filament when said circuit breaker is open and to increase the flow therethrough when the circuit breaker is in closed position.

PAUL A. NOTHS'I'INE.

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