US788493A

US788493A - Incandescent electric lamp.

Info

Publication number: US788493A
Application number: US21504304A
Authority: US
Inventors: Herschel C Parker
Original assignee: Individual
Current assignee: Individual
Priority date: 1904-07-02
Filing date: 1904-07-02
Publication date: 1905-04-25
Anticipated expiration: 1922-04-25

Description

lo6 s4 CROfiEF NC-E PATENTED APR. 25, 1905.

H. G. PARKER. INGANDESOBNT ELECTRIC LAMP.

APPLICATION 'rnnn JULY 2, 1904.

25 M Q W,

A TTORN/i r.

N f X72 amount of light increases greatly with the inessary to employ a tubing capable of withseasonal. o. PARKER,

INOANDESOENT ELECTRIC 'LAMP.

Patented April 25, 1905.

PATENT OFFICE.

OF NEW YORK, N. Y.

en's

SPECIFICATION forming part of Letters Patent Not-788,493, dated April 25, 1905.

Continuation of Serial No. 201,643. filed April 6, 1904- Thil application filed July 2, 1904. Serial No. 216.043.

'1'!) (all whom it may concern..-

Be it known that I, Heuscum. O. PARKER, of New York, in the county of Kings and State of New York, have invented a new and Improved Incandescent Electric Lamp, of which the following is a full, clear, and exact deseription.

My invention relates to improvements in incandescent electric lamps; and the object of my invention is to produce a practically indestructible lamp which has a higher efliciency than the lamp in general use and which is likewise cheaper to manufacture.

My invention is especially intended to produce a lamp in which the incandescent material is arranged in the core formed inside of a refractory translucent tube and in which the incandescing material is raised to a heat sufficient to melt any kind of glass. As the crease of heat, to produce a bright light in lamps of high resistance a state of heat is required which is so much higher than that necessary to melt the most refractory glass that if an attempt is made to heat the resisting matter in a glass tube the latter almost instantly slags and renders the lamp useless. It has been discovered, however, that quartz tubing has the transparent effect of glass and that it will stand the most intense heat to which a contained resisting-body is subjected in producinga light of high efiiciency, and it is necstanding (without slagging) the intense heat indicated. 1 have found, further, that if the tube is essentially straight the resisting-bod y can be packed in powdered or granulated form so closely that'there is little chance of combustion.

In the drawings I have shown the parts greatly exaggerated in order that the construction can be understood; but in practice I use a refractory translucent or transparent tube, preferably of very small bore and of a nature to withstand a heat suflicient to slag glass. in this I pack closely a resisting-body, such as a stable oxid like thorium oxid or carborundum, and at the ends of the tube 1 pack graphite or some better conductor, so that the terminals may connect with this conductor and not be unduly heated. With the resisting matter 1 also incorporate suflicientgraphite to cause the current to pass through it, but not suflicient to reduce resistance too much. Obviously the end portions of the lamp should 5 5 be of less resistance than the body portion,- so that the terminals may not be affected and that the body part will give an efficient light.

With these ends in view my invention consists of an incandescent electric lamp the construction of which will be hereinafter described and the novel features claimed.

Reference is to'be had to the accompanying drawings, forming a part of this specification, in which the letters and figures represent corresponding parts in both the views.

Figure 1 is a longitudinal section of a simple form of lamp embodying my invention;

- and Fig. 2 is a similar view. but showing the resisting part 7 effect of crystallization of the of the lam p. The tube 10 is preferably, and I believe necessarily, of quartz, as 1 have found that this resists perfectly the high heat of the body portion 11 of the lamp, and it has the necessary light-permeable qualities. It is possible that a refractory non-conducting lightpermeable tube can be made of other material; but the essential thing is to have the tube capable of withstanding a heat higher than that required to slag glass. 1 have tried many kinds of 'glass to see if any efiicient results could be attained with it; but as glass melts at approximately 1,5200 Fahrenheit and the heat required to produce a lamp of 5 high efliciency is vastly higher than this it is obvious that the use of glass is out of the question. I am aware also that certain forms of crystals have been used for producing a lamp, the crystals having channels in them in 9 which a conductor is laid; but this is impractical, first, for the reason that such a lamp is enormously expensive, and, second, that it is impractical to keep out the oxygen.

In producing my lamp the tube has the resisting-body 11, preferably of a stableoxid such as described, with a small percentage of graphite mingled with it hammered intothe tube, so that it is packed as tightly as possible. In order to secure the results desired, it is important that the materials forming the core be treethat is, that they have no binder by which the materials are stuck together. Hence the term free in this connection will be understood as meaning independent particles which are not united by a binder. At the ends of this portion 11 I place graphite 12 or other conductor. Behind this 1 pack asbestos 13 to hold the powder in place. Before packing the asbestos, however, the terminals a. of the wires A are embedded in the graphite, and then after the asbestos is in position the ends of the tube are sealed, as at 14. Any suitable cement having the proper coefiicient of expansion and the necessary elasticity can be used for this purpose. I have used carborundum with asuitable binder, such as silica or waterlass.

'l'lie particular iorm of connection 15 not essential; but it is essential that the wires have an excellent contact with the graphite 12.

When the current is turned on, the resistance offered by the body portion 11 causes the latter to be quickly raised to a high heat, and consequently the lamp is made bright instantly. 1 find that there are practically no chemical changes, and so far my experiments have shown merely a slight crystallization, as indicated at 15, on the inner surface of the tube 10; but this takes place at the first heating and does not in any way impair the subsequent efiiciency of the lamp.

Having thus fully described my invention,

1 claim as new and desire to secure by Letters Patent 1. In an electric lamp, a highly-refractory non-conducting tube, permeable to light,aconductive but resisting core of free particles tightly packed within the tube, the ends of the core offering less resistance to current than the intermediate portion thereof, and circuitterminals held in the end portions of the tube.

2. An electric lamp comprising a tube of quartz, a tightly-packed resisting but conductive core of free particles within the tube, the said core being less current resistant at the ends than at the middle portion and circuitterminals connected with the end portions of the core.

3. An electric lamp comprising a tube of quartz, a conductive but resisting filling of free particles tightly packed in the tube, the filling at the ends of the tube ofiering less resistance to a curreutthan the filling in the intermediate portion of the tube and suitable terminals connected to the said conductors.

4. An electric lamp comprising a tube of quartz,a conducting but resisting filling of free particles in the tube, the said filling comprisingastable oxid with asmall percentage of graphite. the filling near the end portions of the tube containing a greater percentage of graphite than the filling in the intermediate portion of the tube, suitable conductors having their ends embedded in the filling at the ends of the tubes, and suitable seals for inclosing the ends of the tube. 5. An electric lamp comprising a tube of quartz, a conducting but resisting filling of free particles in the tube, the said filling comprising a stable oxid with asmall percentage of graphite, the filling near the end portion of the tube containing a greater percentage of graphite than the filling in the intermediate portion of the tube, suitable conductors having their ends embedded in the filling at the ends of the tubes, packing at each end of the filling and suitable seals for inclosing the ends of the tube.

6. An electric lamp comprising a tube of quartz, a conducting but resisting filling of free particles in the tube, the said filling comprising a stable oxid with a small percentage of graphite, the filling near the end portion of the tube containing a greater percentage of graphite than the filling in the intermediate portion of the tube, suitable conductors havingv their ends embedded in the filling at the ends of the tubes, asbestos packing at each end of the filling and suitable seals for inclosing the ends of the tube.

HERSCHEL C. PARKER.

Witnesses:

W. B. HUICHINSON, JOHN T. CAROLAN.