Improvements in or relating to Photographic Cameras.
Year: 1897

page_text: Date of Application (in United Kingdom), 25th June, 1897
Complete Specification Left, 25th June, 1897-Accepted, 18th Sept., 1897
Improvements in or relating to Photographic Cameras.
EUGENE PROSPER PASQUIER, of 244 Boulevard St. Germain, Paris, in the
Republic of France, 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 photographic apparatus forming the object of the present invention consists
of two principal parts.
1. A dark chamber provided with an objective and shutter enabling time or
instantaneous exposures to be made as desired either by hand or by means of a
pneumatic disengaging device.
2. An adjoining chamber to receive the film and its operating mechanism.
Figs. 1 and 2 show the apparatus in side elevation and plan respectively.
Figs. 3 and 4 are respectively longitudinal and transverse sections and
Figs. 5, 6, 7 and 8 are detail views.
The dark chamber itself may be of ordinary construction and may be made of wood
metal or other material covered or not with leather or other material. It has
however in one of its walls an opening A (Fig. 3) which is closed in a light tight
manner when necessary and the use of which will be indicated hereafter.
The film holder or chamber consists of a casing of wood metal or other material
separated from the main chamber in the interior by a partition B (Fig. 3), destined
to prevent light from penetrating to the film contained in the frame and com-
pletely closed by a cover.
This chamber contains 5 rollers and spools which are its principal parts viz.―
The carrying spool C (Figs. 3 and 4) on which is wound the sensitive film.
The indicating roller D which serves to measure off a fresh length of film
after each exposure.
up.
The receiving spool E on which the film which has received impressions is wound
Finally the rollers 7 and 71 (Figs. 3 and 4) the function of which is of the utmost
importance as they ensure by means of a device to be hereinafter described perfeet
tension of the film.
The carrying spool is provided at each end with a central cylindrical shallow
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page_text: hole one of said ends being moreover provided with one or several recesses into
which fit exactly projections of a part 9 (Figs. 4 and 5) to form one whole with
said spool and having a milled edge.
The carrying spool is held in place on one side by a screw terminating in a
cylindrical support and on the other side by a screw preferably of metal and of a
much greater diameter the head of which has an opening sufficiently wide to
enable the part 9 to freely pass,
This screw V is of such length that when it is completely screwed down there
is no clearance between the part 9 and the spool.
The indicating roller D (Figs. 3, 4, and 6)* turns on the points of two metallic
screws or pivots.
It carries at a (Fig. 3) two or more points which passing under the grooved roller
or rollers (Fig. 3) perforate the film and thus mark the spot where it ought to
be cut after it has been exposed in order to divide the different photographs. The
roller D has also at 6 (Fig. 6) a circular gradually inclined groove which when the
roller turns exercises a progressive pressure on the stem of the knob d (Fig. 4)
which on the other hand has a tendency to be pressed inwards by a helical or
other spring.
'
The receiving spool E (Figs. 3 and 4) turns at one end on a pivot similar
to that of the carrying spool and on the other on a part f (Fig. 4)
provided with a ratchet wheel and secured to the spool either by a screw or other-
wise. The ratchet in conjunction with a spring pawl h opposes the backward
movement of the spool (Fig. 1).
The receiving spool is alos provided with a clamp by which the end of the film
is secured when charging the camera and the arrangement of which is clearly
shown in Figs. 3 and 4.
The rollers r and 1 (Figs. 3 and 4) instead of being rigidly fixed as in similar
apparatus are caried on springs i (Figs. 3 and 4); they are consequently movable
and owing to this arrangement it is possible to give the sensitive film an absolutely
flat surface in front of the screen B.
The film chamber finally contains a compensating spring consisting of say two steel
plates secured to a spindle freely turning in two small bearings shown ate and e¹.
(Figs. 4 and 7) and carrying two rods or rollers which press on the carrying and on the
receiving spools. The spindle being loosely carried in its bearings avoids the
differences of pressure which are produced owing to variation of the diameters
of the spool
as the film becomes transferred from one spool to the other when
each of them is acted upon by an independent spring; the compensating.spring
distributing its energy equally between the two spools so that they are subject
to a constant pressure in spite of their varying diameters.
It will be understood that on examining Figs., 3 and 4 how the apparatus is
charged.
The two screws V and v¹ being removed the carrying spool is placed in posi-
tion; vis then screwed in and through the opening in V part 9 is introduced
in such manner that its projecting portions exactly fit the recesses in the spool.
Then V is inserted its central portion penetrating into the cylindrical recess
in the spool after having passed through g.
Then the compensating spring is inserted a certain length of the film is then
unwound and passed over the rollers D and r and held by one hand in this
position. The other hand is passed through the opening A and by causing the
film to pass along the screen B its end is brought under the roller r¹ and the
clamp of the spool E is caused to engage it and hold it fast.
The film presents at this moment an irregular surface.
In order to stretch it a knob m (Figs. 1 and 4) is rotated which causes the
pawl n to engage with the teeth of the part g. Then the part f is caused to turn
in the direction of the arrow (Fig. 1) which causes the receiving spool to
particinate in its movement.
The spool C being blocked by the pawl the film cannot further unwind from

page_text: the spool. Being however pulled by the spool E it exercises on the rollers 7 and 71
an increasing traction which is transmitted to the springs i.
When a slight resistance is felt the rotary movement is stopped and the film
becomes perfectly flat in front of the screen B owing to the tendency of the
springs i to resume their original position.
After exposure it is necessary to replace the portion of film before the screen
by a new section of sensitive surface.
For this purpose it is necessary to disengage the carrying spool by turning the
knob m in the opposite direction the knob d is then pulled out so that the rod
which forms its continuation is caused to come out of its recess.
The part is then turned in the direction of the arrow and the knob d is
released.
The film causes the roller D to participate in its movement and the inclined
groove in said roller (Fig. 6) gradually raises the knob d which then suddenly
falls and strikes against the stop p (Fig. 6).
At this moment the turning of f is stopped the spool C is locked by means of
the knob m and f is again turned through an angle corresponding to 3 or 4 teeth
of the ratchet the new surface substituted for the first one is in the place which
it must occupy and is perfectly stretched.
The operations can be thus continued till the whole roll of film is exhausted.
The combination of the different parts described gives excellent results and
I reserve to myself the right to apply it to photographic apparatus of all kinds
and sizes either with an adjoining frame as in the present instance or with an
independent frame or roll holder.
My experiments have proved to me the great superiority with regard to the
stretching of the film of spring supported rollers, whatever be the shape and the
arrangement of the latter over rollers carried in fixed supports.
Having now particularly described and ascertained the nature of the said in-
vention. and in what manner the same is to be performed I declare that what I
claim is:-
1. In a roll holder or chamber forming part of a photographic camera or
independent thereof spring supported rollers for the purpose of obtaining a flat
strip of film in front of the exposure opening substantially as described.
2. In a roll holder or chamber forming part of a photographic cameral or
independent thereof a pressure compensating device consisting of a spindle freely
rotatable in its bearings and carrying spring arms provided with rollers adapted
to press against the film carrying and receiving spools substantially as described.
3. The combination and arrangement of parts constituting the complete roll
holder or chamber substantially as described and illustrated in the accompanying
drawings.
Dated this 24th day of June 1897