US787428A

US787428A - Incandescent electric lamp.

Info

Publication number: US787428A
Application number: US18788704A
Authority: US
Inventors: Frank H Blackburn
Original assignee: NAT ELECTRIC LAMP Co
Current assignee: NATIONAL ELECTRIC LAMP Co; NAT ELECTRIC LAMP Co
Priority date: 1904-01-06
Filing date: 1904-01-06
Publication date: 1905-04-18
Anticipated expiration: 1922-04-18

Description

No. '787,428'. PATENTED APR. 18, 1905.

- I'. H. BLACKBURN.

INGANDESCBNT ELECTRIC LAMP.

APPLICATION FILED JAN. 6. 1904.

,my 9d.

UNITED STATES Pari-nf FRANK H. BLACKBURN, OF FOSTORl'A, OHlO, ASSlG-i OR TO @dit NATONAL ELECTRIC LAMP COMPANY, OF CLEVELAND, OlilfO, A CORPORATON OF NEW JERSEY.

INGANDESCNT ELEOTFHM;

Application led Janna-ry 6, 3.904. Serial No. 1821,88?.

To all whmn il; may concern:

Be it known that I, FRANK H. BLACKBURN,

a citizen of the United States, residing` at Fostoria, in the county of Seneca and State of Ohio, have invented a certain new and useful Im provement in Incandescent Electric Lamps, ot which the following is a full, clear, and exact description, reference being had to the accompanying drawings. v

This invention is a so-called tipless incandescent lamp-that is to say, an incandescent lamp which has no visible tip.

The tip on an incandescent lamp is the pointed projection which remains attached to the lamp after the exhaustion-tube has been fused olf, which tip seals the hole through which the air is exhausted. Ordinarily these tips are at the Xtreme outer end of the bulb. `Wher ever they are, if in thevisible part of the bulb, 2O they are objectionable for many reasons well understood in this art. .Many elorts have been made to do away with the visible tip; but such eorts have heretofore not resulted in any satisfactory practical construction. in

. a practical construction the exhaustion-tube,

of which the tip is the remains, must be accessible throughout its length during the manufacture of the lamp, so that it can be repaired when broken, and it is very liable to be broken during the repeated necessary hand ling. Said exhaustion-tube must not be attached so near another seal that the glass at the point of attachment is under strain due to the other seal, because thereby the liability to breakage' is multiplied. -It must not require the reduction in the size of the bulb or any variation from the standard size of the lampbase.

A lamp constructed according to the inven- A4C* tion herein described has all ot the necessary characteristics above referred to, and, moreover, it costs no more to make the lamp than it does to make the ordinary lamps in common use with the Avisible tip.

The invention in its entirety consists in incandescent lamp having` its tip projecting,r out from the side of the neck of the bulb and covered, concia. ed, protected by the shell of the lamp-base;. and it consi ts, further, in certain details of construction, 'to be herein- SO after definitely pointed out.

n the drawings, Figure l is an elevation o'tf a lamp-bulb, showing its condition in an early stage in the manuiacture ot' a lamp in accordance with this invention and having the exhaustion-tube secured thereto. Fig. 2 is a similar View of the lamp after the stern has been inserted into and sealed to the bulb. Fig. 3 is a similar view ot' the lamp after the exhaustion-tube has been fused of? and the opening` sealed, but before the base has been applied; and Fig. i is similar View of the completed lamp, one side ot' the neck and ol' the base being in section.

Referring to the parts by letters, A repre sents the lamp-bulb of 'Familiar outline and oi' regular size, (t being the neck thereof.

B represents the stem, whose daring; lower edge is sealed to the lower end or` the neck.

D represents the base oi' the lamp, having' '.70 the usual threaded shell, which is intended to be secured upon the neck in the usual way.

in that part of the'neck fr. which will be -oraced by and covered by the shell (l of the e is a perforation (nl, which is preferably 7 ned before the stem B is sealed to the lower end of the neck. This perforation is in the best construction, as shown, formed in a portion t3 oi said neck which is depressed below the adjacent surfaces, said depression being, asshown, annular, extending entirely around the neck. The exhaustion-tube E is fused to the neck over this perforation, as shown in Fig. 3, and then the stem is sealed terfere with the applic in in 'the usual way of the standard base The shell Z of the base covers, conceals, and protects the tip'.

The described lamp is tipless in the ordinary sense and is quite as strong and no more expensive than the ordinary lamps.

1. In an incandescent lamp, a bulb having a depression in its neck, and the tip which seals the air-exhaustion hole projecting from said depressed portion.

2. In anincandescent electriclamp, the combination of a bulb having a neck and a tip projeeting laterally out from said neck, with a. metallic base having a shell which embraces said neck and conceals and protects said tip.

3. In an incandescent electriclamp, the combnation of a bulb having a depression in its neck and the tip projecting out from said depressed uportion, with a base having a shell which embraces said neck and covers said depressed portion thereof and thereby conceals and protects said tip.

In testimony whereof 1 hereunto alix my 20 signature in the presence of two witnesses.

FRANK H. BLACKBURN.

Witnesses:

. A. H. WINsLow,

E. J. KULAs.