Improvements in and relating to Applying Carbon Filaments to Electric Lamps.
Year: 1892

page_text: Date of Application, 8th Mar., 1892-Accepted. 7th May, 1892
COMPLETE SPECIFICATION.
Improvements in and relating to Applying Carbon Filaments to
Electric Lamps.
I, AUGUSTUS CELANUS CAREY, a citizen of the United States of America,
residing at Lake Pleasant, in the County of Franklin and State of Massachusetts
one of the United States of America, Machinist, 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 :-
Figure 1 is an elevation of a "dead" lamp, showing, by dotted lines, the bulb
opened for renewing the filament.
Figure 2 is an elevation of a lamp in process of renewal according to my
invention.
Figure 3 shows in section and plan, enlarged, the couplings used in one form of
my invention.
Figure 4 is an elevation showing my invention applied to short filament lamps.
Figure 5 is a perspective view of this filament attachment detached.
Figure 6 is a sectional elevation of a single tube attachment.
Figure 7 is a perspective view of a solid coupling applied to this form of my
invention.
Figures 8, 9 and 10 are sections and corresponding plans of various forms of
couplings.
Figure 11 is an elevation of still another form of coupling.
Figure 12 is a section substantially on line x-x of Figure 5.
Figure 13 is a perspective view, and
Figure 14 is a sectional view of still another form of attachment.
Figure 15 is an elevation of a common form of glow lamp supplied with a con-
stricted coupling.
Figure 16 is a partly sectional elevation on a larger scale of the glass standard
and adjacent parts illustrating the constricted coupling,
Figures 17 and 18 are perspective views on a very large scale of two forms of
my constricted coupling.
In all these various forms of my invention, the essential feature is a coupling for
connecting in circuit the filament and leading-in wires.
The primary object of this invention is to provide for supplying incandescent
electric lamps with fresh carbon filaments in place of those that are burnt out.
When the carbon filament of an incandescent electric lamp is burnt out or exhausted
or broken, the lamp is called "dead and commonly goes into the scrap heap, and
the glass bulb and its socket or fitting are a loss. I propose to save this loss and
to renew the lamp repeatedly so far as the carbon filament is concerned. While
this renewal of the lamp is the main object of my invention, it will be manifest that
I can supply new lamps with the carbon filaments by the same means, and in so
doing their subsequent renewal will be facilitated.
In practising my invention I take an exhausted or dead lamp, a, and by heat
reduce the teat, b, to a plastic state, push a suitable tool through it and enlarge the
opening, as shown by dotted lines in Figure 1 and by full lines in Figures 2 and 4.
The exhausted filament, c, is then removed and the leading-in wires, d, cleaned of
adhering parts. If the bulb be foul, it may be cleansed by brushes or other means.
I then take a new filament, and fasten to its ends, by cement, f, or other means,
metallic couplings, g, and inserting the filament thus supplied with couplings into
the bulb, I connect the couplings with the leading-in wires, d, and complete the
union by pinching the couplings about the leading-in wires, or by adding cement in

page_text: those portions of, the. couplings which are to receive the leading-in wires, or by
soldering or electric welding or other means, although I prefer to effect the union
of the couplings and leading-in wires simply by pinching, crimping, or bending, as
more fully illustrated in Figures 5, 6, 7, 12, 15, and 16. A glass tube, h, Figure 2,
having a flaring mouth is then applied to the opened end of the bulb, the air is
exhausted from the bulb, and the bulb sealed by melting the tube and closing it as
indicated by dotted lines in Figure 2, to form the teat, and the tube then removed,
the lamp being then ready for duty.
The couplings may be variously constructed. As shown in Figure 3 they are
made by folding a piece of metal upon itself somewhat like a figure eight (8), thus
forming two tubes, one of which takes the filament and the other the leading-in
wire. Or I may make them of solid wire bored longitudinally with straight sided
holes, as in Figures 7 and 8, or with tapering holes as in Figure 9, or with oppositely
tapering holes as in Figure 10, the tapering holes enabling the coupling the better
to receive the cement; or with a notch, i, Figure 11, to afford an anchorage for the
cement. Or I may make the coupling as a single tube, as in Figures 6, 15, 16, 17
and 18, of folded or of solid metal or of tubular wire, in which case the filament is
applied at one end and the leading-in wires at the other. I may crimp, bend or
pinch the couplings about both filament and leading-in wires, but I prefer to cement
in the filament and bend, pinch or crimp the couplings about the leading-in wires
only. Or I may make the coupling tubular for the reception of the filament and
provide it with a transversely perforated portion, g', through which the leading-in
wire is bent or threaded, as shown in Figures 13 and 14. The simplest and
preferred form of coupling is shewn in Figures 15, 16, 17 and 18, and it consists of
à tube made by rolling up a sheet of metal, as in Figure 17, or by boring a solid
wire, or of a section of tubular wire, as in Figure 18, and constricting it about
midway of its ends as at j. This constriction determines the extent to which the
filament and leading-in wire shall enter the coupling, and moreover insures perfect
electric contact. Another purpose of this constriction of the coupling is this: In
practising my invention, the couplings are placed on wire supports, and then the
filament's ends are inserted in the couplings and cemented. If there be no con-
strictions in the couplings, the cement is apt to run down upon and adhere to the
wire supports and make the removal of the couplings therefrom difficult and expose
the carbon to danger of breaking, but with such constrictions, the cement cannot
pass to the wire supports and hence the couplings will not stick and may be removed
without trouble or danger.
In those incandescent lamps in which the glass tubes or standards which contain
the leading-in wires extend well into the bulb or globe, the filament is short, and in
order to renew the carbon it is a matter of difficulty to determine the proper length
of carbon to get the right resistance, candle-power, etc. This is true, for example,
. of the Edison lamp. I find that I can preserve the proper resistance, candle-
power, etc., by using a relatively long filament by connecting it with the leading-in
wires through the medium of interposed conductors.
Referring now to Figures 4, 5, 6, and 7, I attach the filament to couplings, g, as
before and connect the couplings with pot-hook or S-shaped conductors, k, which
conductors are supplied at their opposite ends with couplings, g, and these couplings
in turn are connected with the leading-in wires. For the reason that these con-
ductors extend toward the butt of the lamp I call them, for convenience, and to
distinguish them, depending conductors.
The couplings and conductors may be crimped together.
By crimping together the wires and couplings a very firm union of the two is
effected, and a joint made which is not materially or injuriously affected by
expansion and contraction. Moreover, such a joint may be straightened out
sufficiently to detach the couplings for renewals of filaments and for other
purposes.
A suitable instrument for crimping the couplings and wires consists of a pliers-
like device whose jaws are toothed to intermesh.

page_text: The constriction may be applied to any or all of the various forms of couplings
shown if desired.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. Applying carbon filaments to the leading-in wires of electric lamps by means
of couplings in which the ends of the filament are secured and the ends of the
leading-in wires are crimped, bent, or pinched, substantially as shown and described.
2. Couplings for securing the carbon filaments of electric lamps to the leading-in
wires, consisting of metallic tubes provided with constrictions, substantially as
shown and described.
3. Applying carbon filaments to the leading-in wires of electric lamps by means
of couplings on the filaments, and couplings on the leading-in wires and interposed
depending conductors, substantially as shown and described.
Dated this 8th day of March 1892.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.