Improvements in Enlarging Apparatus for Photographic Purposes.
Year: 1897

page_text: Improvements in Enlarging Apparatus for Photographic Purposes.
I, LEON GAUMONT, of 57, Rue St. Roch, Paris, in the Republic of France,
Manufacturer of Photographic Cameras, do hereby declare the nature of this
invention to be as follows:-
This improved enlarging or "amplifying" frame is distinguishable by its extreme
simplicity of construction and the readiness with which it may be operated when it
is desired to obtain double or treble enlargements of photographic pictures; the
relations of 1 to 2 and 1 to 3 being those most frequently adopted for enlargements
by amateurs from what I have been able to gather within my experience.
The improved frame consists of a pyramid-shaped case which at its base receives
a frame containing the sensitized surface whereon the image to be enlarged has to
be formed.
At the top of the pyramid there is provided a box with a slide, by the operation
of which the proportions of the enlargement may be fixed at will at 1 to 2 or
at 1 to 3, by varying the distance between the object lens and the sensitized
surface and also the distance between the object glass and the image to be enlarged.
The slide adapted to move in the box has an object lense fitted in it and is
moreover provided with pins or studs which serve to limit the extent of displacement
of the box, while at the same time doing duty as a stop for arresting the slide at
the required distances, by abutting against the ends of the grooves formed upon
the stationary case or sheath wherein the said box and slide are arranged to move.
For the operation of the frame, the box is provided with a handle which enables
the apparatus to be moved to the desired position.
When the frame is adjusted for enlargements in the proportion of 1 to 2, the
box is moved right home to the bottom of the sheath.
When it is desired to enlarge a picture in the relation of 1 to 3, the negative
is placed at the upper part of the slide and the handle
pulled so as to raise the
box. As this movement is being performed, the box carries the slide along with
it until its pins meet the bottom surfaces of the grooves of the sheath, thereby
arresting it. Then the said box continues to ascend until the bottoms of its
recesses in their turn come into contact with the pins; when the frame will be in
readiness for enlarging the negative in the proportion of 1 to 3.
In order to so adjust the apparatus as to make double enlargements (in the
proportion of 1 to 2) the box is pushed home by means of the handle; this box
first descends, carrying the slide along with it, until the pins strike the bottoms
of the grooves; then the said box continues its downward movement until the
bottom surfaces of the recesses in their turn come into contact with the pins.
By such means the apparatus may be exactly set, so that the distance between the
objective and the sensitized surface, as well as the distance between the said

page_text: objective and the picture to be enlarged may always be accurately proportioned
to the required enlargement.
Dated this 10th day of
100
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in Enlarging Apparatus for Photographic Purposes..
I, LEON GAUMONT, of 57, Rue St. Roch, Paris, in the Republic of France,
Manufacturer of Photographic Cameras, 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 improved enlarging or "amplifying" frame is distinguishable by its extreme
simplicity of construction and the readiness with which it may be operated when it
is desired to obtain double or treble enlargements of photographic pictures; the
relations of 1 to 2 and 1 to 3 being those most frequently adopted for enlargements
by amateurs from what I have been able to gather within my experience.
In the accompanying drawing,
Figure 1 is a vertical section of my improved' enlarging frame as arranged
for enlargements in the proportion of 1 to 2; and
Figure 2 is a similar view of the frame arranged for enlargements in the propor-
tion of 1 to 3.
This frame consists of a pyramid-shaped case A which at its base receives a frame
B containing the sensitized surface whereon the image to be enlarged has to be
formed.
At the top of the pyramid there is provided a box with a slide, by the operation
of which the proportions of the enlargement may be fixed at will at 1 to 2 or
at 1 to 3, by varying the distance between the object lense and the sensitized
surface and also the distance between the object glass and the image to be enlarged.
The slide C adapted to move in the box D has an object lense O fitted in it and
is moreover provided with pins or studs a which serve to limit the extent of displace-
ment of the box D), while at the same time doing duty as a stop for arresting the
slide at the required distances, by abutting against the ends and b¹ of the
grooves formed upon the stationary case or sheath E wherein the said box and
slide are arranged to move. For the operation of the frame, the box D is provided
with a handle F which enables the apparatus to be moved to either of the two
positions shewn in the drawing.
In Figure 1, the frame as stated is adjusted for enlargements in the proportion
of 1 to 2, for which purpose the box D is moved right home to the bottom of the
sheath E.
When it is desired to enlarge a picture in the relation of 1 to 3 (Figure 2), the
negative is placed at the upper part of the slide and the handle F is pulled so as
to raise the box D. As this movement is being performed, the box D carries the
slide C along with it until its pins a meet the bottom surfaces b b of the grooves c
of the sheath F, thereby arresting it. Then the said box D) continues to ascend
until the bottom d of its recesses f in their turn come into contact with the pins a;
when the frame will be in readiness for enlarging the negative in the proportion
of 1 to 3.
In order to so adjust the apparatus as to make double enlargements (in the
proportion of 1 to 2) as illustrated in Figure 1, the box D is pushed home by
means of the handle F; this box first descends, carrying the slide C along with

page_text: it, until the pins a strike the bottoms b¹ of the grooves c; then the said box D
continues its downward movement until the bottom surfaces d' of the recesses f
in their turn come into contact with the pins a.
By such means the apparatus may be exactly set, so that the distance between
the objective and the sensitized surface, as well as the distance between the said
objective and the picture to be enlarged may always be accurately proportioned to
the required enlargement.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
An improved enlarging or amplifying frame of simplified construction for the
reproduction of photographic images, such frame comprising a box with a slide
carrying the object lense which, by one single operation, enables the proportions
of the enlargement, viz. either 1 to 2 or 1 to 3, to be varied, by varying the relation
between the picture to be enlarged and the sensitized plate; such frame being
constructed and operating substantially as described and illustrated in the accom-
panying drawing.
Dated thin 9th daw of Tan
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.