A NEW OR IMPROVED HOLDER FOR INCANDESCENT ELECTRIC LIGHTS
Year: 1881

page_text: LETTERS PATENT to David Grahan, of Glasgow, in the County of Lanark,
North Britain, for an Invention of "A NEW OR IMPROVED HOLDER FOR
INCANDESCENT ELECTRIC LIGHTS."
PROVISIONAL SPECIFICATION left by the said David Graham at the
Office of the Commissioners of Patents on the 22nd December 1881.
DAVID GRAHAM, of Glasgow, in the County of Lanark, North Britain.
OR IMPROVED HOLDER FOR INCANDESCENT ELECTRIC LIGHTS."
"A NEW
This Invention which relates to a new or improved holder for incandescent
electric lights consists of a piece of insulating material in the one end of which a
screw thread is cut or a screwed bush may be placed thereon in order to attach the
holder on to the screw of an ordinary burner socket of a gas bracket or gasalier.-
This block or plate of insulating material has placed on it a spring or elastic socket
for holding the parallel or tubular part of the glass chamber of an incandescent
light. The spring or elastic holder is made in two portions, insulated from each
other.-Into each portion a pinching screw passes which when the lamp is placed
in its socket bear upon the two metallic tongues leading and joined to the
platinum or other wires to which the carbon is joined. Thus these pinching
screws form electrical connection between the outside metallic portions of the
holder and the interior of the lamp, so that by their means when a current is
passed through the holder it is transmitted by the pinching screws to the lamp
conductors. The holder may be provided with a switch or an equivalent apparatus
for making and breaking contact.-Electrical connexion with the light holder is
made by passing the wires of a circuit by preference for the sake of convenience
and neatness through the tube of a gas bracket or gasalier out through openings
formed in the side of the nozzle or gas burner socket, these wires being insulated
from the metal of the socket.
In cases where a shade is used over the light for partially obscuring or diffusing
it a gallery of any of the kinds usually employed for holding the shade of a gas
light is attached to the holder.
It is to be understood that in place of pinching screws as herein before described
springs or their equivalents may be substituted for making the electrical connection,
also that the improved holder may be attached to a bracket or gasalier or other
light holder so as to project either vertically upwards or to be suspended vertically
downwards.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said David Graham in the Great Seal Patent Office on the
21st June 1882.
DAVID GRAHAM, of Glasgow, in the County of Lanark, North Britain.
OR IMPROVED HOLDER FOR INCANDESCENT ELECTRIC LAMPS."
" A NEW
My said Invention which relates to a new or improved holder for incandescent
electric lights consists of a piece of insulating material in one end of which a
screw thread is cut or a screwed bush may be placed therein in order to attach the
holder on to the screw of an ordinary burner socket of a gas bracket or gasalier.
This block or plate of insulating material has placed on it a spring or elastic
socket for holding the parallel or tubular part of the exhausted glass chamber of
an incandescent light. The spring or elastic holder is made in two portions
insulated from each other.-Into-cach-portion-a-pinching-screw_passes_which_when_
the lamp is placed in its socket bears upon the two metallic tongues leading and
joined to the platinum or other wires to which the carbon of the lamp is joined.-
Thus these pinching screws form electrical connection between the outside metallic
portions of the holder and the interior of the lamp, so that by their means when a
current is passed through the holder it is transmitted by the pinching screws to
the lamp conductors. The holder may be provided with a switch or an equivalent
apparatus for making and breaking contact.-Electrical connection with the light
holder is made by passing the wires of a circuit by preference for the sake of
convenience and neatness through the tube of a gas bracket or gasalier out through
openings formed in the side of the nozzle or gas burner socket these wires being
insulated from the metal of the socket.
And in order that my said Invention may be properly understood, I now proceed
more particularly to set forth the system, mode, or manner, in or under which the
same is, or may be, used or practically carried into effect, reference being had to
the accompanying Drawings and to the letters and figures marked thereon, that
is to say:
Figure 1, of the accompanying Sheet of Drawings represents in side elevation a
lamp holder constructed according to my said Invention, Figure 2, is a plan of
the same and Figure 3 is a sectional elevation on the line x, y, Figure 2.
The insulating material A which may consist of wood, ebonite, insulate or other
suitable insulating or non-conducting material is preferably forined as shewn as a
somewhat cylindrical body.-The lower part or base of the stock of insulating
material is constructed as shewn more particularly in Figure 3, with a screwed
socket piece a, by which to fasten it upon the screwed nipple or portion of an
ordinary gas pipe on which the ordinary gallery of a gas bracket or gasalier is
usually screwed. Around the block A, of insulating material is attached a metallic
casing or holder made in two portions b, b¹, for the sake of being insulated from
each other as hereinafter more fully described; the upper part of these portions b, b',
is formed as shewn in Figures 1 and 3, of an elastic or spring socket piece b, b¹,
protruding above the top of the block A, for holding the parallel or tubular part or
stem of the glass chamber of an incandescent light; the said elastic parts b, bl, are
formed as shewn with a series of prongs or claws but the upper part of the
socket B, may be constructed in many varied forms to clasp the stem of the glass
globe. This metallic casing or holder is constructed as herein before mentioned in
two portions which are insulated from each other by the insulating space or part b³,
between the two halves or portions of the casing as shewn more particularly in
Figure 1 the two portions of the said casing being preferably secured to the side of

page_text: the block A by screws as shewn.-Through the side of the casing preferably at the
upper part of the block of insulating material A, are passed two pinching
screws, C, C, which act as the conductors of the electric current to the filament
within the vacuum globe as hereinafter more particularly described.-One screw is
passed through each of the portions b, bl, of the casing and projects into vertical
recesses a¹, formed in the side of the insulating block A, the metal being thickened
at b, to hold a sufficient number of the threads of the screws to work in as shewn
in Figures 2 and 3.- When the stem of the lamp is placed within the elastic socket
piece 62, the extremities of the two pinching screws C. are brought to bear upon
the two metallic tongues leading or joined to the platinum or other wires to which
the carbon is joined the extremities of the two tongues being received within the
slots a, of the insulating block A.-Thus these pinching screws form electrical
connections between the outside metallic portions of the holder and the interior of
the lamp, so that by their means when a current is passed through the holder it
is transmitted by the pinching screws to the lamp conductors. The conducting
wires may be attached at any suitable points of the two parts of the metallic
casing B, and the current passed therefrom to the screws.
As before inentioned the two metallic portions b, b¹, of the casing are insulated
from each other that is to say the part b, from the part b¹, which arrangement is
necessary both to make the circuit for lighting and to enable it to be broken when
the light is to be put out, and to effect this completely, the metallic portion b',
is separated from its lower part 61*, by the intervening or insulated part or space b*,
as shewn more particularly in Figure 1.-The switch for effecting the making and
breaking of contact consists of an arm or metallic conducting rod D, working upon a
pin d, which passes diametrically through the block A, as shewn in dotted lines in
Figure 2, but it may be mounted in any other suitable or convenient manner and
is provided with a handle d' of wood or other non-conducting material for moving
it into position by the fingers of the operator.-The switch is so pivoted that at its
pivot the extremity of the arm D, is always in intimate contact with the side of
the portion 6, of the casing, this being effected by the intervention of a ring d³,
against which the arm is brought to bear by the tightening nut and screw d³, at
the opposite side of the block A.- When the switch is moved into its lower position
as shewn in Figures 1 and 2 the lower part of the switch is brought into contact
with the lower insulated metallic ring portion b*, of the casing and the upper part
of the switch being in contact with the upper metallic portion b', the circuit is
completed. When the arm of the switch is brought round to a horizontal position,
the lower part of the arm being thus out of contact with the metallic ring portion b₁*,
the circuit is broken through the intervention of the insulating part or space b*.-
Electrical connection with the two portions b, b', of the casing is made by passing
the wires of a circuit by preference for the sake of convenience and neatness through
the tube of a gas bracket or gasalier out through openings formed in the side of
the nozzle or gas burner socket, these wires being insulated from the metal of the
socket.
In cases where a shade is used over the light for partially obscuring or diffusing
it a gallery of any of the kinds usually employed for holding the shade of a gas light
is attached to the holder.
In the Drawing I have shewn a gallery as consisting of three supports or
brackets E, which are of the ordinary formation and are rivetted or otherwise fixed
as shewn more particularly in Figure 3, to the sides of the two portions b, and b',
of the casing, the parts of the casing where the said brackets are attached being
swelled outwards at the part 65, for the reception of rivet heads 66, which part may
be so formed round the holder or casing as shewn in the Drawings.
It is to be understood that in place of pinching screws as herein before described
springs or their equivalents may be substituted for making the electrical connection,
also that the improved holder may be attached to a bracket or gasalier or other
light holder so as to project either vertically upwards or to be suspended vertically
downwards.

page_text: Having now described and particularly ascertained the nature of my said
Invention and the system, mode, or manner in or under which the same is, or
may be, used, or practically carried into effect, I would observe in conclusion that
what I consider to be novel and original and therefore claim as the Invention
secured to me by the hereinbefore in part recited Letters Patent is :-
The arrangement and construction of holders for incandescent electric lamps
consisting of insulated portions for forming the elastic receiver for the stem of an
incandescent light which portion also contains screws or their equivalents for
making contact with the wires or tongues leading to the filament within the lamp,
and provided with a switch for making or breaking the circuit substantially as
hereinbefore described.
In witness whereof I, the said David Graham, have hereunto set my hand and
seal this Twentieth day of June in the year of our Lord One thousand
eight hundred and eighty two.
DAVID GRAHAM. (L.S.)