Improvements in or relating to Incandescent Electric Lamps.
Year: 1896

page_text: Date of Application, 26th June, 1896
Complete Specification Left, 19th Mar., 1897-Accepted, 24th Apr., 1897
Improvements in or relating to Incandescent Electric Lamps.
We, CAREL MARIE VICTOR ROOTHAAN, JOSEPH PHILIPPUS ROOTHAAN,
CORNELIS ALEWIJNSE, and HENDRIKUS SCHUURMAN, constituting the Firm of
Rootbaan. Alewijnse and Co., Manufacturers, of Nimeguen, in, the Kingdom of
Holland, do hereby declare the nature of this invention to be as follows:-
Our invention relates to incandescent electric lamps and, has for its object to
provide an improved method of securing to the neck of the bulb the cap by which
the lamp is held in its socket.
Hitherto the cap, which consists generally of a cylindrical metal tube loosely
fitting the neck or upper part of lanip, has been secured by means of plaster of
Paris this method of securing has however the disadvantage that the cap cannot be
used more than once because of the expense of detaching the same from a lamp
when the latter is worn out or broken.
By our invention we so secure the cap that it can be very easily, detached from
the lamp if desired, moreover the cost of securing the cap by our improved method
is somewhat less than that of securing it by plaster in the manner hitherto
adopted.
According to our invention the lamp is formed with a constriction or groove
extending round its neck at or near the place where said neck joins the bulb of the
lamp. This is easily formed at the time of manufacture. When we desire to cap
such a lamp we wind a metallic wire or ribbon one or two or a suitable number of
times round the neck in the groove abovementioned. The cylindrical cap is then
slipped on the neck and is adjusted so that its lower edge touches, or nearly
touches the wire in the groove. While the cap is held in this position it is soldered
to the wire either all round or in a suitable number of places and is thereby firmly
secured in place. The separate turns of the wire may be soldered together
if desirable by the same operation but we do not think that this is necessary or
important.
In order to detach the cap from a lamp it is only necessary to melt the solder
and the cap may be readily removed.
Lamp bulbs made with a constriction in the neck as hereinabove described
do not necessarily require to be capped after our improved method but may have
the caps secured by means of plaster of Paris in the ordinary manner if desired.
Our improved method of securing the cap is applicable to various kinds of
caps such as the Edison screw-cap, the bayonet cap and many others.
Dated this. 26th day of June 1896.
W. P. THOMPSON & Co.,
322,. High Holborn, London, W.C., Patent Agents for the Applicants.

page_text: We, CAREL MARIE VICTOR ROOTHAAN, JOSEPH PHILIPPUS ROOTHAAN,.
CORNELIS ALEWIJNSE, and HENDRIKUS SCHUURMAN, all Manufacturers, of
Nimeguen, in the Kingdom of Holland, 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:-
Our invention relates to incandescent electric lamps, and consists in an improved
means and method of securing to the neck of the bulb the cap by which the lamp
is held in a socket.
Hitherto the cap which consists generally of a cylindrical metal tube loosely
fitting the neck or upper part of the lamp has been secured. by means of plaster of
Paris. This method of securing has, however, the disadvantage that the cap
cannot be used more than once because of the expense of detaching the same when
the lamp is worn out or broken.
By our invention we so secure the cap that it can be very easily detached from
the lamp if desired. Moreover, the cost of securing the cap by our improved
method is somewhat less than that of securing the same by plaster in the manner
hitherto adopted.
In order that our invention may be clearly understood we will now proceed to
describe the same with reference to the accompanying drawing which is an
elevation partly sectional of a lamp having a bayonet cap secured thereto
according to our invention.
A is the lamp which is formed with a constriction or groove A' extending
round its neck at or near the place where said neck swells to form the bulb
.proper.
B is a
This groove is readily formed at the time of manufacture.
metallic ribbon or wire wound one or two or a suitable number of times round the
neck in the groove A'. C is the cylindrical cap which is adjusted in position on
the neck so that its lower edge touches or nearly touches the wire B. The cap is
secured in this position by soldering the same to the wire either all round or at
a suitable number of places, the soldering also preventing the wire from uncoiling
and shifting its position in the groove. Where the wire is wound more than once
round the neck the several turns may be soldered together if desirable at the
same time that the cap is soldered to the wire, but we do not think that this is
necessary or important. In order to detach the cap from the lamp it is only
necessary to melt the solder, and the cap may then be readily removed.
After the cap has been secured in place it is preferably filled with plaster or
other suitable insulating material D in which the plates E forming the terminals of
the lamp are embedded.
Our improved manner of securing the cap is applicable to various kinds of caps
such as the Edison screw cap and many others.
The lamp bulbs made with the constriction in the neck as hereinabove described
do not necessarily require to be capped after our improved manner, but may
have the caps secured by means of plaster of Paris in the ordinary manner if
desired.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. The method of securing caps to incandescent lamp bulbs by winding a wire
or ribbon in a groove in the neck of the lamp, and soldering the edge of the cap to
said wire or ribbon, substantially as described.

page_text: 2. An incandescent lamp in which the cap is secured to the bulb by soldering its
lower edge to a coil or coils of wire wound in a groove or constriction in the neck.
of the bulb, said cap being filled or not with insulating material, substantially as-
described.
Dated this 19th day of March 1897.
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester, and Birmingham,
Patent Agents for the Applicants.