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

page_text: Improvements in or relating to Photographic Cameras or Film-
exposing Apparatus.
I, THOMAS HENRY BLAIR, of Naylor House, Chiswick, in the County of Surrey,
Manufacturer, do hereby declare the nature of this invention to be as follows:
This invention relates to that class of instrument used for rapidly taking,
reproducing, or exposing photographic pictures, as large a number being taken
or exposed per minute as is necessary, on a continuous film, for producing the
so-called "living pictures." The object of this invention is to secure the correct
position of each portion of the film on which cach picture is made, during taking
or the subsequent expure.
The invention consists in the employment of pins or equivalent, having by
preference tapered points or ends, adapted to engage with openings in the film,
and, should the openings in the film not register with the pins, to move the film
in either direction as the pointed ends enter, so that when the pins are through
the film the latter is correctly placed, and held during the exposure. The pins
or projections may pass in bearings through the table or casing through which
the film is fed, or through other supports, or they may be carried upon a spring
plate, being operated in either instance by an eccentric or equivalent, which may
be carried upon one of the moving parts or shafts of the apparatus, so that the
pins are caused to enter the film as it is coming to rest and just before the
completion of exposure, to hold it if required during the exposure, and to with-
draw after, during, or even before the exposure according to requirement, leaving
it free to travel in the interval between two exposures.
The shutter which shuts off the light during the time in which the film is being
moved forward is preferably of the reciprocating rocking form, and may be also
operated by an eccentric or equivalent carried upon one of the moving shafts,
and may travel when shutting off the light in a direction the reverse of that in
which the film travels, or, in the same direction, according to requirements.
The film may also be moved forward by the direct action of the shutter or by
an independent reciprocating rocking shaft, according to requirement.
To assist in bringing the film to a more even register, and to avoid the variable
jerk on the supply spool which occurs in most apparatus as the film is being
quickly pulled forward for each exposure, a toothed drum is employed, operating
on the film before exposure to unwind the film from the supply spools; the
surface of this drum revolves at the same speed as that, of the drum upon which
the film is taken up after exposure.
Dated this 7th dor of Lucust 1806

page_text: COMPLETE SPECIFICATION.
'
Improvements in or relating to Photographic Cameras or Film-
exposing Apparatus.
I, THOMAS HENRY BLAIR of Naylor House, Chiswick, in the County of Surrey,
Manufacturer, 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 film-exposing apparatus which
will enable the successive portions of a continuous sensitized film or ribbon to
be rapidly and successively exposed before development for the production of
photographic negatives or positives, or for exposing the film after positives have
been produced upon it, as for example in apparatus in which the pictures are
exposed in rapid succession, either to the direct view of the operator, or to pro-
jection-apparatus for lantern displays.
According to one part of this invention the film-exposing apparatus comprises
devices whereby each section of the film is jerked onward with great rapidity
after exposure in order to lengthen the period which, between such movements,
is available for exposure. By thus lengthening the period of exposure the
efficiency of the apparatus is improved, particularly in respect of the optical
impression produced on the observer of the pictures when they are displayed by
projection. According to other parts of this invention improved means are
provided in such apparatus to ensure the proper centering or registering of each
portion of the film at the time of exposure, with the aperture at which it is to
be exposed.
In the accompanying drawings
Fig. 1 illustrates in end elevation, and
Fig. 2 in side elevation, one construction of apparatus according to this inven
tion, by which the centering and subsequent rapid onward movement of
successive portions of a continuous film is secured, one of the cheek plates of the
apparatus being removed in Fig. 2 and certain of the parts being shown in section,
for the sake of clearness.
The apparatus illustrated in, the before mentioned Figures is intended to be
placed within a suitable casing the latter being provided with doors which permit
of its use in conjunction with projection apparatus, or make the apparatus light-
tight according as the aaratus is used for projecting views or for taking
photographs, respectively.
A A¹ are two cheek-plates, kept apart and retained in proper position relatively
to each other by oss stays A2. B is a spindle, the ends of wich are journalled
in the cheek-plates A A; it carries a spool C of continuous film hereinafter
referred to as the supply spool, to which is supplied a frictional brake to prevent
the film unwinding except when a positive pull is applied to it; this brake and
spool are hereinafter described in detail. D, E and are other spindles, which
also are journalled at their ends in the cheek-plates; of these, E is the driving
spindle to which rotation can be imparted from any suitable source of power, E₁
is a toothed pinion fixed upon the spindle E: with it gear spur wheels D and F
fixed on the spindles D and F respectively. G is a spindle journalled in the
cheek plates A A¹ and geared by a spur wheel G to the spun wheel F1, and so to
the driving spindle E. C² is a spool hereinafter referred to as the receiving spool,
formed of the film which has been exposed; C is film intermediate between the
supply and receiving spools. From the foregoing it will be seen that the

page_text: spindles D E F G are geared together by spur gearing, so that they all rotate
together. when the driving spindle E is operated. The dimensions of the
spur wheels F1 geared to the pinion E, are such that they both have the same
angular velocity when they are turned by the said pinion. Either the receiving
spool C or the spur wheel G¹ is engaged with the shaft G by friction only, so
that the speed of rotation of the receiving spool can vary in relation to that of
the shaft which operates it, in order that the film which is moved, as will herein-
after appear, with a mean linear velocity which is uniform may be properly,
wound on the receiving spool, no matter what amount of film may have
accumulated upon it.
Upon the spindles D and F drums D and F3 respectively are fixed; it is by
these drums that the film, at the place where it is operated by them, is moved
onward with uniform velocity, for on the drum D are projections D and on the
drum projections F, properly placed to engage with perforations C provided
at intervals in the continuous film near its edges.
H is a frame fixed transversely between the cheek-plates A A¹ it supports
four pillars H', which in turn support an open rectangular frame H upon which
is secured a cover plate H³ (Fig. 2). In the frames H H and the cover plate H³
there is a central rectangular passage or opening J (Fig. 1) which when the
apparatus is employed in taking photographic pictures is closed by a block K
which is received in a rebate of the frame H and is readily removable to enable
the image on the portion of the film stetched as hereinafter described across the
opening to be viewed or projected. There is just sufficient clearance H between
the cover plate H3 and the adjacent portion of the frame H to permit the passage
of the film C L L' are guide plates in proximity to the drums D² F2 respectively;
they are attached to the cheek-plates A A¹ and are so disposed as to
prevent the film from leaving the peripheries of these drums around which it is
led from the supply spool C to the receiving spool C in the path indicated by the
line C, which in Fig. 2 indicates in section the portion of the film intermediate
between the supply and receiving spools. The guide-plate L is provided with
an extension L2 over which the film passes from the drum D to the clearance
opening H between the cover plate and the frame H. M are rollers pivotted
between the cheek-plates A A¹ to aid in guiding the film and keeping it on
the drums D F, they are grooved as at M (Fig.1) so as to clear the projec-
tions D3 F3 on the drums 12 F2.
1.
Rotation of the drums D2 F2 which occurs in the direction indicated by the
arrows upon them in Fig. 2 would cause the film to pass from the drum D² to
the drum F continuously and at uniform speed, assuming that the driving shaft E
be rotated uniformly, as it is intended to he; but the apparatus comprises an
intermittent feeding device as well as a retaining device and the former operates
to give the film an intermittent movement in the frame H2 as it passes from the
drum D to the drum F: during the détention of the film in the frame H2 by
the retaining device, which latter will presently be described in detail, the contin-
ued rotation of the drum D2 causes the film above the frame H2 to rise in a loop
such as is indicated by the curve C in Fig. 2 and during the same period the
portion of the film extending from the lower edge of the frame H to the drum F
will be caused by the continued movement of that drum to have the slack existing
therein partially taken up, so as to hang in some such curve as that in which it
is shown in full line. The necessity for the intermittent formation of slack in
the loop C and the partial taking up of slack in the portion of film below the
frame H, will be appreciated when the description hereinafter furnished of the
operation of the rest of the apparatus is perused.
The said retaining and intermittent feeding devices will now be described :-
The retaining device comprises the pins; N with tapered points or ends N¹;
they slide endwise in bearings formed in portions of the frames H H, and have
fitted upon them blocks N which have jaws Na embracing guide hars H secured
in the frames H H aforesaid: by thus engaging the blocks with the guide bars H

page_text: the pins N are prevented from rotating about their own axes, and this is a matter
of importance inasmuch as the pins are in the present instance tapered from one
side only as may be clearly seen in Fig. 2. Instead of arranging the pins N. to
slide endwise in a stationary support they may be fixed to springs constituting
supports which will yield sufficiently to permit them to have the desired range
of motion.
00 are two arms fixed upon a shaft P pivotted between the cheek-plates A A¹
to constitute a rocking frame which is operated in the rotation of the driving-
spindle E by means of an eccentric E fixed upon it, and connected by the strap E3
and rod E to the lower end of the arm 0. Each of the blocks N2 has a pin N
projecting from one side of it and engaging with a lot in the adjacent armis 00
as shown in Fig. 1, so that upon operation of the arms 0 0 by means of the
eccentric they will reciprocate the blocks N and cause the pointed end of the
pins N to be alternately projected across and withdrawn from the passage-way
provided between the frame H and the cover plate IP, through which the film
passes.
For the feeding device a somewhat similar rocking frame is constituted by
two arms carried upon a shaft R pivotted between the cheek-plates A A
and carrying between their free ends a wide roller Q rotatable in hearings in
the ends of these arms; the arms are connected by a cross stay Q to which is
connected an eccentric rod E operated by an eccentric E fixed upon the driving
spindle E. When the shaft Eis nitated the roller Q is raised and lowered in
an approximately vertical path extending downwards from the lower end of the
frame H².
It should he observed that the film on its passage through the lower end of
the frame to the upper side of the drum F2 is led below the wide roller Q2 for a
purpose which will hereinafter he explained.
The operation of the apparatus will now be described. Assuming that the parts
of the mechanism are in the position in which they are indicated in Fig. 2, and
that the film has been placed in the apparatus in the position in which it is shown
in full lines in that view:-In that Figure a portion of the film is being retained
in proper position for exposure by the pins N which am in engagement with the
marginal perforations Cupon rotation of the shaft E in the direction indicated
by the arrow in proximity thereto (Fig. 2) the pins N will commence to with-
draw from the film and the drums D2 and F3 will rotate. As the pins are being
withdrawn by the arms 0 0 from engagement with the portion of the film between
the frame and the cover plate H the arms Q Q will be sharply depressed by
the eccentric thereby causing the roller Q to descend rapidly about midway
in its descent when moving at its maximum speed and when the pins N have
been completely withdrawn from the film, the roller Q strikes sharply the loop
or catenary of film lying in its path between the parts H F and forces that part
of the film to assume a more marked loop form indicated in dotted lines C4 in
Fig. 2. The increase of film in this loop C in the lower part of the apparatus
draws a fresh portion of the film from above the frame H sharply into the space
between that fitime H2 and the cover plate H3 for exposure thus causing the
loop C to disappear for the moment and effecting very rapidly the removal from
the said space of the section of 'the film just previously exposed. At the end of
the downward movement of the roller Q2 the film between the parts D2 and F2 will
have been brought taut and thereafter will travel slowly, that is, at the speed
of the periphery of the drums D 2. The extent of the path traversed by the
roller and the primary sag of the loop on which it acts are so proportioned
relatively to the pitch or distance apart of the pictures on the filne that each step
of the intermittent feed is properly and sufficiently effected by the roller Q, and
this being done the pins N move forward again to reengage and adjust to proper
register a fresh portion of the film in the frame H³.
If by any chance this fresh portion of film has niet heen brought into' exact
register for exposure the bevel points of the pins N act as wedges in their

page_text: passage into the marginal perforations C and impart such slight further move-
ment to the film as may be necessary to properly centre or register the same.
'The movement of the pins N is so timed that they enter the film when it has
arrived at the end of the movement imparted to it in the frame H by the roller Q³,
that is to say that the end of the downward stroke of the latter, while the film
is taut and moving at a much slower speed than that which it! just previously has
obtained from the roller Q; moreover the entry of the pins into the whole of the
film is completed just before it is completely exposed to view or to the rays pass-
ing though the lens, so that when exposed the film will be in proper register.
The pins may hold the film during exposure and withdraw thereafter, or even
withdraw slowly before the shutter returns and ends the period of exposure, leaving
the film free to be moved as described in the interval between the two exposures,
which is shortened as aforesaid by reason of the rapidity with which the roller Q
is caused to operate, and also by reason of the fact that it becomes effective
when moving more or less at its maximum speed. The vertical return movement
of the roller Q2 occurs during the interval in which the film is at rest in each opera-
tion, and in this period the loop C is drawn somewhat tauter into some such form
as is indicated by the full lines in which the film is shown in Fig. 2.
'It will be understood that the greater the length of travel of the roller Qin
proportion to the length of the film to be moved in each descent, the more rapid
may the forward movement of the film be made.
Instead of the rocking arms Q Q a sliding frame reciprocating along both
paths of the film can be used. With reference to the supply spool C and the
receiving spool it will be seen from the foregoing that the former spool
decreases in size as the latter increases, and also that the feed devices inter-
mediate between the two spools by which the film is fed from one to the other,
operate to produce a forward feed at a rate which is constant.
To ensure that film shall not be delivered too freely from the supply spool C,
and to ensure also that despite of the steady increase in the diameter of the
receiving-spool C the film shall be maintained at the desired degree of tautness
both between the supply spool C and the dqum D and between the receiving
spool C and the drum Fa the following arrangements are made:-
Attached to a suitable, fixed point on the framing is one end of a spring A-
the other end A of which hears upon the flange T of a drum T on which the
supply of film is wound; there is no restraint upon the free rotation of the supply-
spool, under the influence of the film in company with the flanged drum T except
the friction of the bearings and the action of the spring As which latter exerts
sufficient retardation upon the flanged drum T and spool C to ensure the main-
tenance of the film between that spool and the drum D always sufficiently taut.
The receiving spoof C2 is in the example illustrated carried on a flanged drum U
which is carried upon the spindle G, and has engaged with it a pin V projecting
from a dise V fixed on the spindle G and entering a hole in one of the flanges U
of the drum. The spur-wheel G is supported upon, but is not fixed to the end of
the spindle G; between that wheel and a pin G fixed in the adjacent end of the
spindle is a spring washer G3 by which the wheel G is kept always in sufficient
frictional contact with the collar G fixed on the spindle G to ensure that although
the wheel G may always e able to effect rotation of the spindle G and spool C
by reason of the frictional engagement existing between the wheel and spindle,
et if by geason of the increasing diameter of the body of film accumulating on
he spool, the periphery of the spool' tends to over-run the film (that is to say,
o wind it up too fast) the wheel will be able to over-run the spool by slipping
t the spindle. Any other form of frictional engagement or brake may be used
vithout departing from my invention.
It will be appreciated that by using a brake on the supply spool C or friction
n the film issuing therefrom and applying frictional driving apparatus to the
pool C the drum D can be dispensed with.
The shutter used with the apparatus shown in Figs. 1 and 2 is preferably, one

page_text: which rotates continuously and is fixed upon a shaft S journalled in bearings A
on the cheek plate A and geared, by a bevel wheel B which is fixed upon it,
to a bevel wheel Es fixed upon the shaft E.
In exposing the film for projection a shutter will not always be necessary as when
exposing scenes which have been rapidly taken, for the film is then carried ahead
with such speed that the change is not noticeable to the eye of the observer.
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 film exposing apparatus of the kind described the combination with a
film support such as H of pins such as N in operative connection with the driving
shaft and movable in or upon stationary or on elastic supports for the purpose
described.
2. In a film exposing apparatus of the kind described the combination with
a driving shaft such as E of pins such as N stationary guides and mechanism
such as arms 0 0¹ and eccentric E2 by which the pins are reciprocated substan-
tially as described.
3. In a film-exposing apparatus of the kind described the combination with
a support such as H2 of pins N tapered as at N¹ guide bars H and blocks N2 to
engage with the pins and guides so as to prevent the pins from turning about
their own axes.
:
4. In a film-exposing apparatus of the kind described the combination with a
driving shaft E and oscillating frame Q Q' of devices to reciprocate the frame
for the purpose described.
5. The combination with a driving shaft such as E of pivotted pins N and a
shutter and oscillating frame such as QQ operatively connected with the driving
shaft.
6. The combination and arrangement of parts constituting the complete film
exposing apparatus, substantially as described and illustrated in the accompany-
ing drawings.