Improvements in or relating to Photographic Cameras or Film- exposing Apparatus.
Year: 1896

page_text: Date of Application, Toth June, 1890
Complete Specification Left, 15th Mar., 1897-Accepted, 17th Apr., 1897
Date of Application, Toth June, 1o90
Complete Specification Left, 15th Mar., 1897-Accepted, 17th Apr., 1897
Improvements in or relating to Photographic Cameras or Film-
exposing Apparatus.
A communication from THOMAS HENRY BLAIR, of The Chestnuts, Northborough,
Massachusetts, United States of America, Manufacturer.
I, ALFRED JULIUS BOULT of 111 Hatton Garden in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:-
This invention has for its object to construct a camera so as to enable portions of
a continuous sensitized film or ribbon to be rapidly and successively exposed for
producing photographic negatives or for exposing the film after the pictures have
been produced thereon as for example in apparatus in which the pictures are exposed
in rapid succession either to the direct view of a spectator or by projection on to say
a sheet for lantern displays.
The film or ribbon is provided with perforations at or near each edge and a roller
or drum provided with teeth for engaging with these perforations feeds the ribbon
through the apparatus.
One end of the film is secured to a supply roll or spool and the other end to a
receiving roll or spool the latter of which is mounted on a shaft on which is also
mounted a spur wheel gearing with a toothed wheel rigidly secured on the shaft of
the toothed-drum. Either the receiving spool or the spur wheel is frictionally
engaged with its shaft so as to allow the speed of rotation of the receiving spool to
vary in relation to that of the drum, and the film consequently to be wound on the
drum at a uniform speed no matter what amount of film may have accumulated on.
it. The film may be held in close contact with the toothed drum by two rollers in.
which are formed two grooves to accommodate the teeth of the drum.
The before mentioned wheel gears with a spur pinion secured on a shaft on each end
of which may be secured a crank disc. These crank discs may be connected by links.
with the two ends of a rod secured to one end of the shutter which is free to
reciprocate in fixed guides and at its opposite end may be provided with
a roller.
The shutter which is preferably of rigid construction, works close
against the front of a casing immediately behind which passes the film, this
casing being provided in order to keep the shutter out of actual rubbing
contact with the film. The film may be held in proper working position upon
a table by one or more spring-controlled rollers and through this table as well
as the back of the camera casing there is formed an opening through which
the "picture" may be viewed for focussing purposes. At the back of the opening
is fitted a door or slide which may be removed for focussing or viewing purposes and
replaced when the negatives are to be taken. A light-tight casing may extend from
the lens back to the shutter; in all other respects the camera body, which may
consist conveniently of only one main compartment, is light-tight.
The operation of the before described apparatus is as follows:-
The strip or ribbon of film having been previously wound on the supply spool
and properly passed behind the shutter and made fast to the receiving spool, the
focussing is done directly on the film by removing the slide and adjusting the lens,
the portion of film then exposed being subsequently discarded as it is rendered

page_text: useless by exposure. When the camera is brought into proper focus the shaft is
rotated either by hand or power. Towards one end of each stroke of the shutter
which stroke is considerably longer than the length of the film exposed at each
exposure, the roller carried by the shutter is pushed against the film and causes a
certain length of it (an exposure length) to be unwound from the supply spool, the
film during this unwinding operation travelling in the same direction as the shutter.
Immediately thereafter the last named roller is moved away from the filin, which
at that time and at the part immediately behind the lens and casing remains at rest,
and at the other end of its stroke the shutter opening is brought into coincidence
with the lens and the exposure consequently made. The shutter then moves
cnwards and draws off another exposure length from the supply spool that last
drawn off having at that time been taken up by the continuously rotating receiving
spool; in other words it may be explained that the receiving spool in its continuous
motion takes up the same amount of film as that intermittently unwound by the
reciprocating shutter.
To prevent the film being exposed at both the upward and downward strokes of
the shutter the latter may be provided with a cover plate having an exposure
opening. which, during the movement of the shutter in one direction would
correspond with and allow light to pass through the shutter opening and, during
the movement of the shutter in the reverse direction would be moved away from,
the shutter opening which, at that time would be closed by an opaque portion of the
cover plate.
The cover plate may conveniently be connected to the shutter by means of say
two. T-headed pins or equivalent secured to the latter, engaging with two slots in
the former, and in which slots the pins are free to slide; or the reverse of this
arrangement may be provided. The cover plate is preferably provided with an
adjustable stop plate by means of which the effective size of the shutter opening
may be regulated to suit the amount of light required to be admitted at each
exposure, this stop plate constituting' the abutment surface against which one of the
pins strikes to move the cover plate along with the shutter. The cover plate if
desired may be acted upon by a suitable brake so as to prevent it from moving,
except when positively operated by the shutter, although at the rapid rate at which
the shutter is operated the inertia of the cover plate may be sufficient to render such
a brake unnecessary.
When the shutter is in its lowest position the opening thereof is out of line with
the lens and light-tight casing and covered by an opaque portion of the cover plate
and when the shutter is moved along for making the exposure the cover plate for a
brief interval remains stationary either under the influence of its own weight or
otherwise and when the pin abuts against the stop plate, the shutter opening is in
line with the cover-plate opening lens and light-tight casing so that at that moment
the exposure is made. At the opposite end of the stroke when the movement of
the shutter is reversed the cover plate either under the influence of its own weight
or otherwise remains at rest for a brief interval so that the shutter opening is moved
out of coincidence with the cover plate opening and is covered by an opaque portion
of the cover plate the shutter and cover plate then moving together to the end of
the stroke when the shutter is again moved back and the cover plate momentarily
remains stationary as before explained.
When the before described mechanism is employed for exposing the film or
ribbon after the pictures have been produced thereon as for example, in apparatus
in which the pictures are exposed in rapid succession either to the direct view of a
spectator or by projection on to say a sheet for lantern displays, the before
mentioned door of the apparatus is removed.
Dated this 16th day of June 1896.
BOULT & WADE,
Agents for the Applicant.

page_text: Improvements in or relating to Photographic Cameras or Film-
exposing Apparatus.
A communication from THOMAS HENRY BLAIR, of The Chestnuts, Northborough,
in the State of Massachusetts, United States of America, Manufacturer."
I, ALFRED JULIUS BOULT, of 111 Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, 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 has for its object to construct a camera so as to enable portions of
a continuous sensitized film or ribbon to be rapidly and successively exposed for
producing photographic negatives or for exposing the film after the pictures have
been produced thereon, as for example in apparatus in which the pictures are exposed
in rapid succession either to the direct view of a spectator or by projection on to say
a sheet for lantern displays.
The film or ribbon is provided with perforations at or near each edge and a roller
or drum provided with teeth for engaging with these perforations feeds the ribbon
through the apparatus.
In the accompanying drawings,
Figure 1 is a vertical section of a camera constructed in accordance with this
invention.
Figure 2 is a side elevation of a part of Figure 1.
Figure 3 is a section on the line 3-3 of Figure 2.
Figures 4 to 7 inclusive are views showing an alternative arrangement of the
shutter mechanism shown in Figures 1, 2 & 3.
The film A is drawn from the supply roll or spool B and the other end is attached
to the receiving roll or spool C the latter being mounted on the shaft C' on which
is also mounted a spur wheel C2 gearing with a toothed wheel D rigidly secured on
the driving or drum shaft D'. Either the receiving spool C or the spur wheel C
is frictionally engaged with the shaft C' so as to allow the speed of rotation of the
receiving spool to vary in relation to that of the drum, and the film consequently to
be wound on the receiving spool at a uniform speed no matter what amount of film
may have accumulated on it. The film between the supply and receiving spools is
held in close contact with a toothed drum D2 by two rollers E in which are formed
two grooves E to accommodate the teeth of the drum D².
The wheel D gears with a spur pinion F secured on a shaft F' on each end of
which is secured a crank dise F. These crank discs F2 are connected by links F³
with the two ends of a rod F secured to one end of the shutter G which is free to
reciprocate in fixed guides H and at its opposite end is provided with a roller G'.
The shutter G which is preferably of rigid construction, works close against the
front of a casing J immediately behind which passes the film A this casing being
provided in order to keep the shutter out of actual rubbing contact with the film.
The film may be held in proper working position upon the table K by one or more
spring-controlled rollers L and through this table as well as the back of the camera
casing M there is formed an opening M' through which the "picture" may be
viewed for focussing purposes. At the back of the opening M is fitted a door or
slide N which may be removed for focussing or viewing purposes and replaced
when the negatives are to be taken. A light-tight casing O extends from the

page_text: lens P back to the shutter G ; in all other respects the camera body, which may
consist conveniently of only one main compartment, is light-tight.
The operation of the before described apparatus is as follows:-
The strip or ribbon of film having been previously wound on the supply spool B
and properly placed behind the shutter G over the toothed drum D' aud made fast
to the receiving spool C, the focussing is done directly on the film A by removing
the slide N, and adjusting the lens P, the portion of the film then exposed being
subsequently discarded as it is rendered useless by exposure. The camera being
properly focussed the shaft D' is rotated in the direction indicated by the arrow in
Fig. 1 either by hand or by means of the crank handle D³ or power and thus feeds
the film A through the machine by means of the toothed drum D and also sets the
reciprocating shutter G in motion. Towards one end of each stroke of the
shutter G which stroke is considerably longer than the length of the film exposed
at each exposure, the roller G' is pushed against the film A as shown in Fig. 1 and
causes a certain length of it (an exposure length) to be unwound from the supply
spool B, the film during this unwinding operation travelling in the same direction
as the shutter. Immediately thereafter the roller G' is moved away from the film,
which at that time and at the part immediately behind the lens P and casing O
remains at rest, and at the other end of its stroke the shutter opening G2 is brought
into coincidence with the lens and the exposure consequently made. The shutter
then moves onward and draws off another exposure length from the supply spool B
that last drawn off having at that time been taken up by the continuously rotating.
toothed drum D2 and passed on to the frictionally driven receiving spool C; in
other words it may be explained that the toothed drum D2 and receiving spool C
in their continuous motion take up the same amount of film as that intermittently
unwound by the reciprocating shutter.
For exhibiting the pictures after having been made, the apparatus may be used to
advantage without at any time cutting off the light, or another form of shutter, for
instance a revolving one can be used, in which case an open frame, instead of the
shutter itself, would carry the roller G¹.
The stroke of the shutter G being greater than each exposure-length of the film,
the latter is therefore jerked ahead with great rapidity as it must travel at the
speed of the shutter with the additional speed at which the continuously rotating
toothed drum D' is taking up the film. Therefore the shutter can be adjusted so
that its stroke may be increased or decreased as it is found desirable to change the
speed at which the film is jerked ahead and thus increase or decrease the length of
time that it remains at rest out of the portion of time required for a cycle of
operations.
To prevent the film A. being exposed at both the upward and downward strokes
of the shutter G the latter may be provided with a cover plate Q having an
exposure opening Q' which, during the movement of the shutter in one direction
would correspond with and allow light to pass through the shutter opening G2 and
during the movement of the shutter in the reverse direction would be moved away
from the shutter opening G2 which at that time would be closed by an opaque
portion of the cover plate.
.
Figs. 4 to 7 inclusive show a cover plate applied to a shutter of the construction
represented in Figs. 1, 2, and 3. Figs. 4, 5 and 6 being sections showing the
shutter and cover plate at three different parts of the stroke and Fig. 7 an elevation
of Fig. 6.
The cover plate Q may conveniently be connected to the shutter G by means of
say two T-headed pins or equivalent G³ secured to the latter, engaging with two
slots Q in the fornier, in which slots the pins C³ are free to slide or the reverse of
this arrangement may be provided. The cover plate Q is preferably provided
with an adjustable stop plate Q by means of which the effective size of the shutter
opening G may be regulated to suit the amount of light required to be admitted
at each exposure, this stop plate Q3 constituting the abutment surface against

page_text: which one of the pins G3 strikes to move the cover plate along with the shutter..
The cover plate Q if desired may be acted upon by a suitable brake so as to
prevent it from moving except when positively operated by the shutter G although
at the rapid rate at which the shutter is operated the inertia of the cover plate may.
be sufficient to render such a brake unnecessary.
When the shutter is in its lowest position the opening G2 thereof is out of line
with the lens P and casing O and covered by an opaque portion of the cover
plate Q and when the shutter is moved along for making the exposure of the cover
plate Q for a brief interval remain stationary either under the influence of its own-
weight or otherwise and when the pin G abuts against the stop plate Q3, the
shutter opening G2 is in line with the opening Q₁ lens P aud casing as shown
in Fig. 4 so that at that moment the exposure is made. The opposite end of
the stroke when the movement of the shutter is reversed the cover plate Q either
under the influence of its own weight or otherwise, remains at rest for a brief
interval so that the shutter opening G is moved out of coincidence with the cover-
plate opening Q, and is covered by an opaque portion of the cover plate shutter C
and cover plate Q then moving together to the end of the stroke when the shutter
is again moved back and the cover plate momentarily remains stationary as before
explained.
When the before described mechanism is employed for exposing the film or
ribbon after the pictures have been produced thereon as for example in apparatus
in which the pictures are exposed in rapid succession either to the direct view of a.
spectator or by projection on to say a sheet for lantern displays the door N of the
apparatus is moved.
It is obvious that though the continuously rotating toothed drum D2 is described!
as having been found to be the best practical means of moving the film yet a plain
drum with or without a special means for obtaining a hold upon the film may equally.
well be employed.
Having now particularly described and ascertained the nature of the said inven-.
tion 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. In apparatus for successively exposing different parts of a strip of photographic.
film moving the film by means of a shutter.
2. In apparatus for successively exposing different parts of a strip of photographic
film, the employment of a film moved by the shutter.
3. In apparatus for successively exposing different parts of a strip of photographic
film the combination with a toothed drum such as D2 of a shutter by which the film
is moved substantially as described.
4. In apparatus for successively exposing different parts of a strip of photographic
film the combination with a reciprocating adjustable shutter or frame such as G
which intermittently feeds the film forwards of a continuously rotated drum such
as D substantially as and for the purpose described.
5. The combination and arrangement of parts constituting the complete
apparatus for successively exposing different parts of a strip of photographic film
substantially as described and illustrated in Figures 1, 2 and 3 of the accompanying-
drawings.
6. In apparatus for successively exposing different parts of a strip of photographic
film the combination with a film actuating reciprocating shutter such as G of a cover-
plate movable thereon for the purpose described.
7. In apparatus for successively exposing different parts of a strip of photographic
film the combination with a film actuating reciprocating shutter and cover plate
movable thereon of an adjustable stop for limiting the movement of the cover plate.
in relation to that of the shutter for the purpose described.
8. In apparatus for successively exposing different parts of a strip of photographic.
film the combination and arrangement of parts constituting the complete shutter.

page_text: mechanism substantially as described and illustrated in Figures 4, 5, 6, and 7 of
the accompanying drawings.
1005
T. H. BLAIR.
Boult & Wade,
Agents for the Applicant.