Year: 1899

page_text: Date of Application, 4th Apr., 1899
Complete Specification Left, 4th Jan., 1900-Accepted, 10th Feb., 1900
I, GERALD ST. JOHN DAY, of 18, Barker Street, Oldham, Lancashire, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
-
The improvements relate to electric arc lamps and have for object to dispense
with all feeding or moving mechanisms for actuating the carbons, in manner
hereinafter to be described.
To accomplish this and to effect my improvements, I provide the requisite
carbons of such cross.sectional form as will enable one to be encircled or sur-
rounded, so to speak, by the other. The forms of such carbons can be greatly
varied, but in all cases the inner carbon is arranged as a core within the other.
One form I employ, and by preference, is that of a carbon rod, surrounded by a
cylindrical carbon or tube and each of which is affixed to a suitable stand or
holder, and arranged with the requisite space between the same. The outer
cylinder of carbon is connected to one wire of an energised circuit, and the inner
rod which may be either solid or hollow-is connected to the other wire.
The arc is established at the free ends of these fixed or stationary carbons
which burn in candle form without the need of any movement or feeding mechan-
ism therefor whatsoever.
Although the circular form of the outer and inner carbons arranged concen-
trically is preferred, other forms in cross section may be employed, such as the
triangle and all suitable polygonal forms, and the sides of the circular or other form
of enclosing carbon need not be continuous sectionally.
The arc may be established in various ways, either by leading the same by means
of a small piece of carbon attached to a rod to be used like unto a torch, or by
a. tilting mechanism, which, will enable one carbon to be inclined to the other
momentarily, for the purpose of starting the light when the current is switched on.
When the carbons are burnt down the light may be arranged to automatically
go out either by so shaping the carbons at the lower end that their distance apart
is increased, or by arranging suitable stops, or otherwise, as will readily be
understood.
When desired, more than one pair of concentric carbons may be employed, that
is to say, circular or otherwise formed carbons may enclose other carbons to such
extent as may be requisite for the purpose in view.
Variations in detail, such as the form and length of the carbons; the mode of
mounting the same in or upon the holder; the means employed in starting the
light the arrangements for automatically or otherwise stopping the same, and
other variations may be made without departing from the peculiar character of
the invention.
Dated this 1.4
J
1000
WILLIAM GADD, C.E.,
64, Barton Arcade, Manchester,
Agent for Applicant.

page_text: Improvements in Electric Arc Lamps.
I, GERALD ST. JOHN DAY, of 18, Barker Street, Oldham, Lancashire, Electrical
Engineer, 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:
-
"
The improvements relate to electric arc lamps and have for object to dispense
with all feeding or moving mechanisms for actuating the carbons, in manner
hereinafter to be described.
To accomplish this and to effect my improvements, I provide the requisite
carbons of such cross sectional form as will enable one to be encircled-or sur-
rounded, so to speak, by the other. The forms of such carbons can be greatly
varied, but in all cases the, inner carbon is arranged as a core within the other.
One form I employ, and by preference, is that of a carbon rod surrounded by a
cylindrical carbon or tube and each of which is affixed to a suitable stand or
holder, and arranged with the requisite space between the same.
The outer
cylinder of carbon is connected to one wire of an energised circuit, and the inner
rod which may be either solid or hollow-is connected to the other wire.
The arc is established at the free ends of these fixed or stationary carbon's
which burn in candle form without the need of any movement or feeding mechan-
ism therefor whatsoever.
Although the circular form of the outer and inner carbons arranged concen-
trically is preferred; other forms in cross section may be employed, such as the
triangle and all suitable polygonal forms, and the inner carbon may be formed at
its free end with a thickened portion extending across as well, as longitudinally
beyond the end of the outer carbon. The sides of the circular or other form of
enclosing carbon need not be continuous sectionally.
The arc may be established in various ways, either by leading the same by means
of a small piece of carbon attached to a rod to be used like unto a torch, or by a tilt-
ing mechanism which will enable one carbon to be inclined to the other, for the
purpose of starting the light when the current is switched on.
When the carbons are burnt down the light may be arranged to automatically
go out either by so shaping the carbons at the lower end that their distance apart
is increased, such as making the outer carbon internally, or. the inner carbon
externally, or both, in taper form, or by arranging suitable stops, such as an
insulator round the lower part of the inner carbon, or notches in the carbons, or
otherwise.
1101
When desired, more than one pair of concentric carbons may be employed, that
is to say, circular or otherwise formed carbons may enclose other carbons to such
extent as may be requisite for the purpose in view.
But that the improvements may be better understood I will, with the aid of the
accompanying drawings, proceed more fully to describe means employed by me.
1
DESCRIPTION OF DRAWINGS.
Fig. 1 is a sectional plan view of the underside of Fig. 2, which latter figure is
an elevation partly in section (having certain portions broken away) of one form
of arc lamp with the carbons arranged according to my improvements, and
Figs. 3, 4, 5, and 6 are cross sectional views of other forms of carbons similarly
arranged. The same letters indicate corresponding parts wherever they occur.
a is the, innermost carbon surrounded by one or more carbons b.
In Fig. 2 the carbon a is supported by the socket piece a¹ of the holder c, which
socket piece passes through a hole in the lower part of the holder, and is pivotted

page_text: at a² on the standard a³ (partly dotted for sake of clearness), and such standard is
separated by insulation from the holder c. The socket piece a¹ carries the lever *,
one end of which lever is attached to the holder by the insulated spring a³ and
the other end of the lever carries the adjustable stop a6. The carbon 6, in the
same figure, is supported by the socket piece b¹. This outer carbon is arranged
to be connected through the conducting material of which the holder is com-
posed, and by the terminal t¹, to one wire of an energised circuit, and the inner
carbon is arranged to be connected by wire to the electro-magnet e, which, in
turn, is to be connected, by wire to the terminal t, to the other wire of the circuit.
The terminal t is insulated from the holder c.
The arc is established at the free ends of the carbons which burn in candle form
without the need of any movement of feeding mechanism therefor whatsoever.
The arc may be established in various ways, but, as shown in Fig. 2, this con-
nection for starting the light when the current is switched on is automatically
accomplished in the following manner:-
Before the current is switched on, the spring as acting on the lever at tilts the
socket piece a¹ on its centre of turn a² (as illustrated by dotted lines) until there
is sufficient contact between the free ends of the carbons a, b, for the arc to 'be
established whenever the current of electricity is passed through the apparatus;
but when this takes place the electro-magnet e (the core of which may have at
the centre of its top surface a small piece of non-conducting material) becomes
operative in manner well understood, and attracts towards it the end of the stop a
and with it that end of the lever a, thus producing the effect of bringing the
carbon a into the working position shown. It is obvious however that the carbon b
may be tilted for the same purpose, or the arc be otherwise established.
Variations in detail, such as the form, and comparative diameters and lengths
of the carbons, the mode of mounting the same in or upon the holder; the means
employed in starting the light; the arrangements for automatically or otherwise
stopping the same; and any well known means may be employed, if necessary,
for preventing the arc travelling unduly away from the free ends of the carbons,
and the lamp may or may not be made to burn in a partial vacuum within a globe;
and the relative lengths of the carbons, when in position, may be temporarily
adjustable, such as for the purpose of producing a beam of light for stage and
other effects, and other variations may be made without departing from the
peculiar character of the invention.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
In arc lamps of candle form, a core or cores of carbon within one or more other
carbons, and provided or not with automatic means for establishing the arc, for
the purpose and in manner substantially as herein shown and described.
Dated this 3rd day of January 1900
WILLIAM GADD, C.E.,
64, Barton Arcade, Manchester,
Agent for Applicant.