Improvements in or relating to Holders for Photographic Films.
Year: 1885

page_text: Improvements in or relating to Holders for Photographic Films.
I ALFRED JULIUS BOULT of 323 High Holborn in the county of. Middlesex,
Engineer, do hereby declare the nature of this invention (a communication from
George Eastman of Rochester, New York, United States of America) to be as
follows:-
This invention consists of an indicating mechanism for use with roller holders for
photographic films more especially such as are described in the specification to
Letters Patent, No 15542 dated November 25th, 1884, and in connection with
which the present mechanism will be described.
The object is to indicate on the outside of the case the position of the film and,
to this end I secure upon or in connection with the end of the measuring roll,
described in the above named specification, a disc having one tooth which gears
with another disc having a suitable number of recesses on the principle of the well
known Geneva stop mechanism. The proportion of the gearing may vary but
usually four to one is appropriate, because the circumference of the measuring roll
is usually one fourth of the length of the portion of film required for one exposure,
and so one revolution of the second. wheel or disc of the indicating mechanism is
equal to one exposure. Ordinary gearing in the same proportion might be used,
but the Geneva stop action is preferred because the indicator cannot turn or slip.
The spindle of the second wheel is squared and upon this fits a sliding indicator-
knob squared internally to match the spindle; when pushed on the spindle the
knob turns with it-when withdrawn it is clear of the spindle and can be turned
independently of it. The knob is graduated or carries an index so that in con-
junction with a suitable scale plate or equivalent, the exact position of the film can
be ascertained; thus if the exposed portion of the film has not been wound quite off
the exposure table the indicator will show this, and the operator can rectify it and
avoid spoiling the plate by exposing a portion of it twice over.
This mechanism may be used alone or in connection with the warning device
described in the specification N° 15542.
By making one of the recesses in the second wheel shallower than the others.it
may be made to operate the spring of the warning device.
1007

page_text: I ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
Engineer, do hereby declare the nature of this invention (a communication from
George Eastman of Rochester, New York, United States of America, Manufacturer)
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :—
This invention consists of an indicating mechanism for use with roller holders
for photographic films more especially such as are described in the specification to
Letters Patent N° 15,542 dated November 25th 1884 and in connection with which
the present mechanism will be described.
The object is to indicate on the outside of the case the position of the film and
to this end I secure upon, or in connection with the end of the measuring roll
described in the above named specification a disc having one tooth which gears
with another disc having a suitable number of recesses on the principle of the well
known Geneva stop-mechanism. The number of recesses in the second wheel may
vary but four is a convenient number as the circumference of the measuring roll is
usually one fourth of the length of the portion of film required for one exposure
and therefore one revolution of the second disc indicates that a sufficient amount
of film has been measured off to suffice for one exposure.
Ordinary gearing may be used consisting of a pinion and toothed wheel the
latter being preferably four times the diameter of the former for the reasons
previously given.
In order to indicate the position of the mechanism on the outside of the case the
spindle of the second wheel is squared and upon this fits a sliding knob the stem
of which is squared internally to match the spindle. The stem of the knob passes
through an opening in the box opposite the end of the spindle and when pushed
over the spindle the knob turns with it, when withdrawn it can be turned
independently thereof. The knob is graduated or carries an index so that in
conjunction with a suitable scale plate or equivalent the exact position of the film
can be ascertained so that if the exposed portion of the film has not been wound
quite off the exposure table the indicator will show this and the operator can
rectify the error and so avoid spoiling the plate by exposing a portion of it
twice over,
Figure 1 of the accompanying drawings represents a Geneva-stop-movement
suitable for my invention and Figure 2 illustrates the manner of applying the same
in conjunction with other indicating apparatus.
Figure 3 is a partial side elevation shewing the application of ordinary gearing
instead of stop mechanism and also a modified form of indicator. Figure 4 is a
partial end view thereof and Figure 5 a plan.
Figure 6 shews part of case and external portion of indicator in side elevation
and Figure 7 is a vertical section thereof showing the internal mechanism of the
indicator.
Referring to Figures 1 and 2 A is the measuring roll indicated by the letter I'
in the specification herein before referred to. To one end of this roller is fixed a
disc or pinion A¹ having a single tooth A2 B is a wheel having 4 recesses or
spaces B¹ with one of which the tooth A* engages upon each complete revolution of
the roller A and by so doing imparts one quarter of a revolution to the wheel B

page_text: which will then remain stationary until the roller A completes its revolution
during which period the wheel B is locked by reason of the convex periphery of
the disc A¹ fitting into the concave portions B2 of the periphery of the wheel B
which lie between the spaces B¹ after the manner of a "Geneva-stop."
The end of
the spindle B³ of the wheel B which projects beyond the frame work C is squared
and over this slips the stem of the knob D which is squared internally to correspond
with the spindle. This stem passes through an aperture in the light-tight casing E
and through the centre of a dial plate F attached to the outside of the case E and
divided into any convenient number of parts. By means of an index or pointer F¹
attached to the knob D the exact state of the film as regards the amount wound off
can be ascertained. When it is required to turn the knob D independently of the
measuring roll A and wheel B it can be done by withdrawing it a sufficient
distance to clear the end of the spindle B³. To prevent the entire withdrawal of
the spindle and the consequent admission of light into the casing E a collar D¹ is
fixed around the end of the spindle D.
•
In Figures 3, 4, 5, 6 and 7 which show the use of ordinary toothed gearing in
place of the "Geneva-stop" mechanism 'above described, A represents the measuring
roll mounted in frame work C and E the light-tight casing. To the end of the
roll A is attached a pinion G which gears with a toothed wheel H-mounted fast
on a revolving stud or spindle H¹ which passes through the frame work C. For
reasons previously described these wheels are preferably in the proportion of four
to one to each other though other proportions may be adopted. On the end of the
spindle H¹ is an indicating knob or button H' on the face of which is an index
line H³ and an annular groove H*. The groove H* is formed for the purpose of
receiving one end of an eye piece J which consists of a short flanged tube passing
through a collar K. By this means a light-tight joint is ensured. A short slot J¹
is formed in the eye piece into which enters a screw J' which serves to prevent the
eye piece from being entirely withdrawn. When it is desired to remove the
machine or holder from its case the flange of the eye-piece J may be graduated as
shewn in Figure 6 and by comparing the graduations and the index line H³ the
amount of film wound off can be ascertained.
Having now particularly described and ascertained the nature of the said
invention as communicated to me by my foreign correspondent and in what
manner the same is to be performed I declare that what I claim is :-
1. The combination with a roller holder for photographic films of an indicating
apparatus which shows from outside the case the position of the film or of the
exposed portion thereof substantially as specified.
2. In a machine or apparatus such as herein described the combination with the
measuring roll A of an indicating mechanism substantially such as specified and
shewn in Figures 1 and 2 of the accompanying drawings.
3. In a machine or apparatus such as herein described the combination with
roll A pinion A¹ wheel B square-spindle B³ and knob D of a dial plate F and
index F¹ the latter attached to the stem of the knob substantially as and for the
purpose specified and illustrated in Figures 1 and 2 of the accompanying drawings.
4. In an apparatus such as described the combination with roll A pinion G and
wheel H of an index button H³ and eye-piece J substantially as specified.
5. The combination with the wheel H of a knob or button such as H³ having an
annular recess H' substantially as specified.