Improvements in Apparatus for the Use of the Electric Light for Photographic Purposes.
Year: 1894

page_text: Date of Application, 22nd Mar., 1894-Accepted, 19th May, 1894
COMPLETE SPECIFICATION.
Improvements in Apparatus for the Use of the Electric Light for
Photographic Purposes.
I, ANDREW GEORGE ADAMSON, of 136 Buchanan Street, Glasgow, Photographic
Artist, 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 Improvements in Apparatus for the Use of the Electric
Light for Photographic Purposes, and is a further development of my Patent
No. 21,379, A.D. 1893.
In order that my invention may be properly understood and readily carried into
effect I have hereunto appended three explanatory sheets of drawings in the
several figures of which corresponding parts are marked with the same letters of
reference.
Figure 1 is a general view of the apparatus embodying my improvements.
Figure 2 is a detail view in side elevation of the carriage showing its swivel and
electrical connections.
Figure 3 is an end view of the same.
Figures 4 and 5 are side and end views respectively of the end of beam, also
showing its swivel connection with the reflector and feed conductors for electric
lamps.
Figure 6 is a fragmental section of the reflector showing its pivotal arrangement
for giving to it a motion independent of that of the beam.
Figures 7 and 8 are respectively elevation and side sectional elevation of the
resistance coil.
As will be seen from the drawings the reflector A is suspended at one end of a
bracket or beam B by a swivel arrangement C, and has a counterweight D at its
opposite end. This bracket or beam B is connected to a carriage E which runs on
rails F by means of a tubular swivel F', so that the apparatus can be moved from
one end of the studio to the other or adjusted. The dome-shaped_chamber A. is
pivoted at G so that it can be adjusted to any suitable angle. The lamps are
placed round the inside of this chamber A, and a central one is suspended from its
roof. The feed conductors h h are led from any suitable source to the carriage E
by the metallic pieces e, e, and from thence they are led to that part thereof having
a swivelling motion by the metallic springy pieces f. f. The said springy
pieces f,connect the metallic pieces e e to the metallic rings g, g¹ in which are
clamped the feed conductors h h. These conductors are carried along the beam B
by the insulated pieces i, i to the reflector A, where by a system of metallic rings
and conductors similar to that last described they supply a powerful current to the
lamps placed round the rim of the reflector. As illustrated in Figure 6 the
reflector is shown cased with wood. At opposite sides a pivot or bolt a is passed
through the reflector near its largest diameter. Upon a double flanged ring
screwed to the reflector A and through which this pivot or bolt a passes the
reflector is capable of being turned in a horizontal axis. This pivot or bolt a has
mounted upon it at either end a metallic ring a' provided with an eye in which is
clamped by screws the end of the feed conductor. The current passes through the
pivot or bolt a to the underside of the reflector, and an annular conductor supplies
the current to the lamps. The conductor for supplying current to the central lamp
is led from the carriage down through the tubular swivel F along the beam B to
its end thereof down the tubular swivel F2 and out through the centre of the dome
of the reflector to the central lamp or lamps. By this arrangement of connections

page_text: and swivels F and F the beam and reflector are capable of being turned completely
round.
The resistance coil consists in its simplest form of a framework or casing of box
like form in which is mounted a ring or part ring of carbon J. This ring is
embedded in plaster of Paris or analogous cement. The current enters the
resistance coil at by means of the metallic disc j and is led to the contact arm k
having a handle which is pivoted to the switchboard centrally with the said carbon
ring J. By this arrangement a rubbing contact is obtained with varying degrees of
resistances by causing the current to pass through the ring at different positions of
The greater degree of resistance offered to the current is when the arm k
is turned round upon the carbon ring and reaches the point x. The current leaves
the ring at Z.
its arc.
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. The general arrangement, combination and operation of the parts of the
apparatus for the use of the electric light for photographic purposes substantially
as hereinbefore described in Figures 1 to 6 of the accompanying sheets of
drawings.
2. The form of resistance coil, substantially as hereinbefore described and shown
in Figures 7 and 8 of the accompanying sheets of drawings.
Dated this 20th day of March 1894.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.