Apparatus for Copying Tracings by Means of Artificial Light.
Year: 1896

page_text: Date of Application, 9th Jan., 1896
Complete Specification Left, 8th July, 1896-Accepted, 8th Aug., 1896
PROVISIONAL SPECIFICATION.
Apparatus for Copying Tracings by Means of Artificial Light.
I, BENJAMIN JAMES HALL, of 39 Victoria Street, in the County of Middlesex,
Iron and Steel Works Engineer, do hereby declare the nature of this invention to
be as follows:-
This invention has for its object the arrangement & construction of apparatus
suitable for obtaining photographs of tracings by means of electric or other artificial
light capable of acting on sensitized paper.
It consists of a cylinder of glass or other material transparent to the photographic
rays, mounted vertically, horizontally, or at any required angle; this cylinder is so
arranged that the tracing or negative, with the sensitized paper at the back, may
be rolled around it, on the outside, & pressed tightly thereon by means of a blanket
of felt, canvas, rubber or other substance.
The cylinder is used in combination with an arc lamp which can be passed inside
it, throughout its entire length, a clockwork or other escapement being provided
to regulate the motion, in order that all exposed portions of the sensitized paper
may be acted upon. If desired the movement of the light may be controlled by
hand.
In place of the electric arc lamp, the photographic rays of a suitably exhausted
vacuum tube through which an electric current is passed, may be used. This tube
may be moved, or remain stationery within the cylinder during the photographing
process.
In order to economise light & hasten the process of photography, cylinders of
varying diameters & lengths may be employed to suit the dimensions of tracings to
be rolled thereon.
Dated this 8th day of January 1896.
BENJAMIN JAMES HALL.
COMPLETE SPECIFICATION.
Apparatus for Copying Tracings by Means of Artificial Light.
1, BENJAMIN JAMES HALL, of 39 Victoria Street, Westminster, in the County
of Middlesex, Iron and Steel Works 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 object of this invention is to construct and arrange apparatus whereby
tracings can be photographed by means of artificial light in a more expeditious
manner and with a better result than with apparatus as heretofore made and used.
The apparatus which forms the subject of this invention comprises a cylinder of
glass, or other material which is transparent to photographic rays, and an electric
or other source of artificial light which is capable of acting on photographic
sensitized paper. The tracing to be copied and the sensitized paper are wrapped
round the outside of the cylinder and secured in contact therewith by a suitable
backing. The artificial light is placed inside the cylinder and the apparatus is

page_text: preferably so mounted that the cylinder can be rotated on its longitudinal axis
and also travelled along outside the light, or the light may be mounted to rotate
and be travelled along inside the cylinder, or the light may be made to rotate and
the cylinder be travelled along outside thereof, or the cylinder may be made to
rotate and the light be travelled along on the inside thereof so that all exposed
portions of the sensitized paper may be equally brought under the action of the
photographic rays.
In the accompanying drawings I have shewn one form of my invention in which
an electric arc lamp is mounted so as to be travelled along inside the cylinder, the
latter being mounted with its longitudinal axis vertical and adapted to be rotated
by hand or by mechanical means.
A is the arc lamp which is suspended by a cord B passing over suitable guide
pulleys C and having a counterbalance weight D secured at the end. The lamp
may be lowered into the cylinder E by hand, or a dash-pot, a clockwork or other
escapement, or any other suitable mechanical means may be adopted for controlling
and regulating the motion of the lamp into the cylinder and for passing it from top
to bottum thereof by a gradual and continuous motion. A step-by-step movement,
with a period of rest between successive steps sufficient to allow of the requisite
exposure may be adopted when the lowering is effected by hand.
The cylinder E is placed on a base plate or table F having a vertical shaft G
fitting into a footstep bearing H and supported in a bracket frame J. The table
may be rotated by hand or by means of a strap passed over the pulley K or other-
wise as found convenient.
The tracing to be copied is rolled tightly around the outside of the cylinder
with the sensitized paper at the back, and a blanket of felt, canvas, rubber or
other suitable material is wrapped thereover to form a backing which is secured in
any convenient manner.
In place of the electric are lamp, the photographic rays of a suitably exhausted
vacuum tube through which an electric current is passed, may be used. This tube
may be moved or remain stationary within the cylinder during the photographing
process, as desired. In fact any source of artificial light which is capable of
acting on photographic sensitized paper may be used, and a cylinder or open ended
body of any material which is transparent to the photographic rays may be used
with the artificial light.
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 ;-
Apparatus for copying tracings by means of artificial light, comprising a cylinder
or open ended body of glass or other material which is transparent to photographic
rays and around which the tracing and photographic sensitized paper are wrapped,
and an electric or other source of artificial light which is capable of acting on
the sensitized paper, the said light to be passed into the cylinder or body
substantially as described.
Dated this 8th day of "Tul. 1900
F. W. GOLBY,
36, Chancery Lane, London, W.C., Patent Agent for the Applicant.