Improvements relating to the Sealing of Wires in Glass.
Year: 1893

page_text: Date of Application, 30th Jan., 1893
Complate Specification Left, 30th Nov., 1893-Accepted, 30th Mar., 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad by JOHN BLEECKER TIBBITS, of Hoosac, New York,
United States of America, Clergyman.]
Improvements relating to the Sealing of Wires in Glass.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex do hereby declare the
nature of this invention to be as follows:—
This invention relates to the sealing of wires in glass and its chief object is to
provide means whereby electric light conductors may be sealed into the glass of
incandescent lamp bulbs and yet be capable of carrying a large current.
Heretofore it has been the custom to seal platinum "leading in" wires into
incandescent lamps to carry the current to the carbon filament and the glass has
been generally sealed direct to the wire, but even then the differential expansion of
the "leading in" wires at high temperatures with respect to the glass is sufficient
to crack the glass, and thus electric incandescent lamps have been able to carry
only a very small current.
By my invention I so seal wires into glass that the expansion of the said wires
can take place without cracking the glass.
For this purpose I provide a ring of platinum or other suitable metal having
Hanged ends; such a ring I call an "eyelet ring." The glass is sealed to the
flanges of the eyelet ring and the wire conductor is passed through the ring to the
interior of the bulb. The conductor is secured to the eyelet ring by a suitable
medium such as silver solder; or it may be secured by electrolytic action or by
other suitable method or means. When the conductor is heated and expands, the
eyelet ring owing to the annular interstice between its flanges does not press against
the glass so as to crack it.
The eyelet rings may be made in various forms such as for instance of a bobbin
shape or of two truncated cones joined by their truncated apices, or in the shape of
an ordinary eyelet such as is used in boots for example.
A very useful method of employing eyelet rings according to my invention in
sealing wires into an incandescent lamp bulb is as follows,-A glass stem through
which the conductors pass has two teats or tubular projections into each of which
an eyelet ring is inserted and sealed in the manner hereinabove described. The
vacuum bulb may be sealed to the stem at one extremity and contignous to the
socket or lamp holder.
My improved mode of sealing wires into glass may be advantageously applied to
vacuum tubes.
It will be understood that I reserve to myself the right of varying the method of
carrying out my invention in detail without départing from the nature thereof.
Dated this 30th day of January 1893.

page_text: COMPLETE SPECIFICATION.
Improvements relating to the Sealing of Wires in Glass.
1, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :—
This invention relates to the sealing of wires in glass and its chief object is to
provide means for sealing such conductors into incandescent lamp bulbs as shall be
capable of carrying a largo current.
Heretofore incandescent lamps have been provided with platinum "leading-in"
wires and the glass has generally been sealed direct to the wires but even then the
heat generated in the said wires has often been so great and has expanded the same
so much as to crack the glass. Lamps made in this manner therefore have been
able to carry only a small current, in fact no lamp in which the glass was sealed
to any part liable to take current could be relied on for use with heavy
currents.
By my invention I seal wires in glass in such a manner that the said wires can
expand to a considerable extent without cracking the glass and I am thereby
enabled to seal thick wires into glass, which wires are capable of carrying a heavy
current. I do this in the manner following, that is to say,
I secure to the wire a ring of a shape hereinafter fully described and then seal
the flanges or edges of the ring to the glass. The wire is thereby elastically
supported in the glass so that expansion of the wire can take place without injury
to the glass.
In order that my invention may be more clearly understood I will now proceed.
to describe the same with reference to the accompanying drawing in which,
Figure 1 is an elevation of an incandescent lamp having leading-in wires sealed
in according to this invention.
Figures 2, 3 and 4 are detail views shewing the method of sealing hereinafter
fully described.
Like letters of reference denote similar parts in all the figures.
A is the lamp bulb, B the filament, and C, C, the leading in wiree.
For the purpose of sealing the leading-in wires C, a ring C' of platinum or other
suitable metal is provided. "Said ring is preferably of the shape shewn in Figure 2,
which is formed of two truncated cones joined by their truncated spices, or the ring
may take the form of an ordinary eyelet such as is commonly used in boots for
example. I have tried other forms of ring such as a bobbin shape for example, but
the results are not satisfactory. The wire B is passed through the ring and secured
thereto as shewn in Figure 3, by a suitable medium such as silver solder, or it
he secured by electrolytic action or by other suitable method or means. The wire
and ring are now placed in a tubular glass stem D and the glass is fused to the
ring the glass worker at the same time gently compressing the glass. The tube and
wire now appear as shown in Figure 4.
may
The glass tube D can now be secured in the side of any glass vessel so that the
wire C will pass from the outside to the inside of the vessel.
In the case of incandescent lamps to the making of which as above mentioned
this invention is particularly applicable, I preferably prepare two tubes on one base
as shewn at D D Figure 1. The wires C are then sealed into the tubes in the
manner heroinabove described and the filament B is secured to the wires in any
suitable manner. The tubes D with the filament are now sealed into the lamp bulb
at the part marked A' Figure 1, the bulb is then exhausted of air and hermetically
sealed off in the well known fashion.

page_text: By using an eyelet ring in the manner above stated the glass is not sealed to the
conducting wire, as the eyelet is not a part of said wire, but is merely soldered or
otherwise united thereto.
Wires capable of carrying large currents can be sealed into lamp bulbs or the
like in the manner hereinabove described without danger of cracking the glass by
expansion when the current is passed through. Hitherto incandescent lamps made
for use with large ourrents have usually been constructed with a number of single
leading-in wires separately sealed into the glass but all being joined to the same
filament, this is a very costly method of manufacture and moreover is not efficient.
By my method of sealing this process is obviated, also the. eyelet which I use
affords a certain amount of elasticity at the point of sealing and allows the
conductor to expand if required owing to the fact that a small annular space is left
at the apices of the cones which is free from glass as shewn at D' in the drawings.
Moreover the eyelet is much more easily manipulated by the glass worker than a
oylindrical wire can be.
My improved method of sealing wires into glass may be advantageously applied in
the manufacture of vacuum tubes as well as to incandescent lamps and is useful in
many other cases.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. The method of sealing wires in glass, which consists in socuring an eyelet
ring to the wire and then fusing the glass to the eyelet ring, substantially as
described.
2. A glass vessel having a wire sealed therein by means of an eyelet ring with or
without an annular space around said ring, substantially as described.
3. An incandescent electric lamp having leading-in wires sealed into the glass in
a inanner substantially as hereinabove described.
Dated this 30th day of November 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, Loudon, W.C., Agents for the Applicant.