US2053574A - Flasher bulb - Google Patents

Description

Sept. 8, 4936; Y P. A. NOTHSTINE I FLASHER BULB Filed Aug. 18, 1928 Patented Sept. 8, 1936 UNITED STATES Arem" orriee FLASHER BULB Paul A. Nothstine, Dayton, Ohio Application August 18, 1928, Serial No. 300,561

5 Claims. (01. 176-14) descent lamp or in a radio tube, or the like, an

My invention relates to flashing lamps, and more particularly to an incandescent lamp having incorporated therein as a part of its unitary structure, a thermostatic control member, having operative connection with the lamp filament, whereby an intermittent flashing action is effected.

The present construction is a further development of that shown and described in copending application, Serial No. 206,566 filed July 18, 1927, wherein the thermostatic flasher switch or control element is located interiorly of the bulb in the same compartment with the filament. In the present method of assembly, the tubulation stem of the lamp bulb is utilized as a support for the thermostatic control element within the hollow mount. The present thermostatic control means may be applied to existing lamps as purchased in the open market.

The object of the invention is to simplify the structure, as well as the means and mode of operation of automatic flasher lamps, whereby they will not only be cheapened in construction, but will be more efficient in use, positive in operation, uniform in action and unlikely to get out of repair.

In the accompanying drawing, wherein is shown the preferred, but obviously not necessarily, the only form of embodiment of the invention, Fig. 1 is a side elevation partly in section of an incandescent lamp bulb of standard commercial type to which the present invention has been applied. Fig. 2 is an enlarged detail view illustrating the application of the thermostatic flasher to a standard commercial lamp bulb. Fig. 3 is a detail perspective view of the thermostatic flasher switch removed from the mount. Fig. 4 is a detail sectional view of a modification wherein the flasher switch is hermetically sealed within the chamber of the bulb mount. Fig. 5 is a detail sectional view of a further modification wherein the flasher switch is mounted directly upon the wall of the mount or stem within the bulb. Fig. 6 illustrates a further modification showing the mounting of a resistance element or automatic rheostat within the mount in lieu of the thermostatic switch.

Like parts are indicated by similar characters of reference throughout the several views.

While the present invention is directed primarily 'to the incorporation of an automatic flasher element as a unitary part of an incandescent lamp, it will be understood that the means and method herein shown and described may be employed to incorporate in an incanautomatic rheostat or resistance element, or any other filament regulating or control member.

Referring to the accompanying drawing, l is the bulb of a standard commercial type incandescent lamp, 2 is the screw base for attachment to the socket or lighting fixture. Such lamp bulb I is formed with an inwardly projecting hollow or tubular mount 3, the lower end of which,

during the process of lamp manufacture is flared 10 outwardly at A and united with the marginal walls of the bulb I. The inner end of the mount 3 while heated to plastic condition is compressed about the filament leads 5 and 6 which are sealed in such contracted or compressed portion I,

known as the press. Projecting within the bulb I from the press I is the standard or support 8 upon which is carried the illuminating fllament 9 connected with the circuit leads 5 and 6. Attached interiorily to the hollow mount 3 adjacent to its press and communicating with the interior or the bulb I through the wall of the hollow mount 3 is a tubulating stem 'or evacnation tube It. Through this stem or tube ID the oxygen contents of the bulb I is exhausted. If the lamp is of the so-called gas filled type, a charge of inert gas may be admitted through the same tubulation stem Ill. After exhausting the bulb I to cause a vacuum therein, or after filling the bulb with an inert gas the end of the tubulation stem I8 is sealed. This is the usual construction of a commercial type incandescent lamp and per se, forms no part of the present invention. The present flasher lamp has a wide field of usefulness for decorative purposes as to provide a twinkling lamp for a Christmas tree, and carnival use for which purposes the use in large numbers of separate flasher means in the present lamp circuits is prohibited by their cost. The present lamp may further be employed for general sign and signal purposes.

Filament control-In applying the present invention to a commercial incandescent lamp, as described, the control element, whether it be a thermostatic switch, a rheostat or resistance element, or a safety fuse, such element is located within the compartment or chamber I I interiorly of the mount 3. In a simple form, as illustrated, abi-metal thermostatic bar I2 of comparatively small dimensions is secured to a split collar or band is, preferably having a degree of resiliency or spring action. The spring collar I3 is slidingly adjusted upon the tubulating stem I!) and over one of the filament leads, which in the present instance is the lead 5. In its adjusted position the spring band I3 surrounding the supporting stem Ill also encloses the end of the lead 5, which for greater security, and to prevent accidental displacement of the thermostat supporting band I3 is turned upwardly into a hook form exteriorly of the band or collar I3. Ordinarily the clamping action of the collar upon the filament lead will afford sufiicient contact. However, to insure a perfect electrical connection the filament lead 5 may be soldered, welded or otherwise integrally united to the collar I3 or directly to the thermostatic bar I2. To make this connection eificiently and economically, a small deposit of solder may be placed upon the spring collar I3 before mounting it upon the tube I6. After being adjusted exteriorly of the tube and the lead 5 a small heated rod or wire may be introduced into the recess H, and sufiicient heat applied to the solder deposit to unite the lead 5 with the collar I3. Located upon the stem I5 in spaced relation with the bar supporting collar I3 is a second collar I which carries a contact I5, preferably though not necessarily, or silver, for engagement of the thermal bar I 2. Attached to the collar I4 by soldering, welding'or otherwise is the continuation 5 of the filament lead. Surrounding the bar I2 is a heater coil I6 of fine Wire, one end of which is connected with the bar 52 or with the collar I3, while the other end is connected with the contact supporting collar I4. Thus the heater coil I6 is introduced into the filament lead and permanently connects the portions 5 and 5'. This heater coil is of sufiicient resistance that solong as the current passes through the heater coil the filament 9 will not become incandescent, or in any event, will glow but dimly. As the coil I6 heats the thermal bar I2 the latter will be warped or flexed under influence of unequal expansion of. its component metals until the free end of the thermal bar I2 engages with the contact I5 upon the supporting collar I 4. This will form a shunt bridging the heater coil is and connecting the filament lead portions 5 and 5 directly one with the other from the collar I3 to the collar I4 independently of the heater coil. The current thus passing through the thermal bar causes the filament 9 to become incandescent during the period of contact of the bar I2 with the contact I5. During this time the heater coil I5 cools and permits cooling of the thermal bar I2, the reaction of which effects the breaking of the contact between the bar I2 and the contact I5, thereby again bringing the heater coil into the circuit. Current again passing through the heater coil heats the thermal bar I2 and the contact is again re-established. This alternation of make and break between the thermal bar I2 and the contact I5 upon the collar I4 is continued indefinitely, eifecting an intermittent fiashing of the lamp filament 9.

For ordinary commercial use, for signs and signal purposes, and the like, the thermostatic chamber II within the hollow mount 3, is not sealed. It is, however, enclosed and protected by the metal-lie screw base 2. There may be conditions of use, however, wherein it is desired to operate the thermostatic element I 2 within a vacuum or within a body of inert gas, such as neon, helium, or the like. In such case, the tubulating stem I is burned oif or sealed within the chamber I I of the mount 3 so that it does not project beyond the base end of the bulb I, and a sealing disc I! is applied to the bottom of the bulb I, and its margins fused thereto after the installation of the thermal control means. The

leads and 6 in such event are brought out of the bulb between the sealing disc I1 and the base margin of the bulb being sealed in the joint while the material is in a plastic condition.

To facilitate the engagement of the lead wires 5 and 5 with the respective collars I3 and i4 these collars are preferably formed with a slight crimp or interiorly grooved bead I3, which will conform to and enclose the end of the lead wire while the remainder of the spring collar will conform closely and tightly to the tubulating stem IE]. Obviously, other means of mounting the 7 thermal bar I2 upon the tubulating stem I6 may be employed. In the event that the control element is applied to a bulb that does not include a tubulating stem I5, or if it be desired to mount the element independently of such stem the thermal bar I2 and its cooperating contact I5 may be mounted upon expansible collars or rings I9 engaging the interior walls of the hollow mount 3 under expansive tension as shown in Fig. 5. In Fig. 6 there is shown a modification, where in lieu of the thermostatic bar I2 there is substituted a control element 20 which may be a resistance element or automatic rheostat, or in lieu thereof, such element 20 may comprise a fuse, or other electrical element regulating or controlling the filament 9. As a protection against possible short circuiting of the second filament lead 6 upon the supporting collars I3 or I4 such lead is preferably, though not necessarily insulated in the chamber I I by slipping over such lead a short length 22 of insulating material of tubular form.

In the event the control element is hermetically sealed within the mount the chamber I I may be exhausted by fusing of a tube to a disc I1 and blowing a hole through the softened disc before assembly, through which the oxygen may be removed, and if desired, a change of inert gas admitted. The thermal bar I2 is preferably, though not necessarily tapered, whereby it is of less width at its free end. This renders it somewhat more sensitive and facilitates the flexing action.

From the above description it will be apparent that there is thus provided a construction of the character described, possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification 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 thestatute 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 details 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. An incandescent lamp having a hollow filament mount and an evacuation tube extending through the interior of the mount, a thermostatic switch member, a mounting collar therefor slidingly carried by the tube, a contact collar for engagement by said switch, also slidingly carried by said tube, one of the lamp filament leads being connected with the switch member, a continuing circuit lead connected with the contact collar and interconnected with each other by the circuit closing action of the switch,.an d a heater coil also enclosed. within said hollow mount and bridged across the thermostatic switch for influencing the action of said switch to efiect intermittent flashing operation of the lamp.

2. The combination with an incandescent lamp having a hollow filament mount and an evacuation tube extending therethrough, of a thermostatic circuit switch located within said hollow mount, means for engaging said switch with said tube, a contact member with which the switch cooperates, means for engaging said contact with said tube in spaced relation with the engagement of said switch, said switch being adapted intermittently to engage said contact to effect a flashing action of the lamp filament.

3. The combination with an incandescent lamp having a tubular mount for the lamp filament through which the lead conductors extend, a tubular stem mounted in and concentric with said mount, of a thermostatic make and break assembly including a fixed contact carried by said stem and a movable contact carried by a thermostatic element mounted upon said stem.

4. As an article of manufacture, a stem assembly including an exhaust tube, and a make and break mechanism coaxially arranged about and carried by said exhaust tube and disposed lengthwise with respect to the tube.

5. The combination with an incandescent lamp having a tubular mount for the lamp filament through which the lead conductors extend, a tubular stem mounted in said mount, of a thermostatic make and break assembly including a movable contact carried by a thermostatic element having one end thereof mounted in fixed relation upon said stem, and a contact arranged in fixed relation with respect to one end of said thermostatic element and located in the path of the movable contact.

PAUL A. NOTHSTINE.

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