Year: 1896

page_text: Date of Application, 3rd Dec., 1896-Accepted, 27th Feb.. 1897
Figs. 4, 5 and 6 are detail-views relating to the cam-groove 12;
Fig. 7 shows one of the arms 13 of the fork in frout elevation and side
elevation;
Fig. 8 shows a photographic strip having its edges provided with circular or
oval apertures arranged at equal distances apart; and
Fig. 9 shows the lever 8 separately.
Upon a shaft mounted in plates 2 and 3 there is keyed a toothed wheel. 4
gearing into a pinion 5 keyed on a shaft 6 upon which is fixed a pinion 7. Upon
one end of this shaft 6 there is fixed a slotted lever 8 in the slot of which is
adapted to slide a roller 9 revolving about a small shaft whose other end carries
another and similar roller 10 sliding in the cam-groove 12. This cam-groove is cut
in a metal plate fixed on another plate 11 connected to the plate 3. The shaft of
the rollers 9 and 10 is mounted in an arm 13 of a fork mounted on an axle 15 of a
jointed frame 16. The arms 16 turn at their other ends about the axis of a
shaft 17. Each of the arms 13 and 14 of the fork carries a pointed part 18 or 19.
The plates 2 and 3 are fixed at right angles to a plate 20 provided on the right-
hand side with an aperture 21 in front of which is arranged a frame 22 mounted on
an axle 23. This frame may be kept in place by means of a pivoted catch 24.
Through the plate 20 passes a shaft 25 upon one of the ends of which is keyed a
bevel-wheel 26 gearing into the pinion 7. Upon the other end of the shaft 25
there is fixed a shutter 27 which is provided with openings. The motion of the
shutter is regulated in such a manner that the full portions will pass in front of the
aperture 21 whilst the sensitive strip is moving as hereinafter described, and that
the openings thereof will so pass whilst the sensitive strip is at rest.
Above the aperture 21 there is arranged a roller 28 that is free to rotate and
serves simply as a guide. A drum 29 is fixed on a shaft carrying a grooved
pulley 30 corresponding to a similar pulley 32 which is keyed on the shaft I and
with which it is connected by means of a small cord 31. The shaft 1 may be
actuated through crank 33 by means of a handle 34.
The cam-groove that we employ has the shape of a D as shown in Fig. 4. This
enables it to impart alternately to the arms 13 and 14 of the fork, a rectilinear
movement and a curvilinear movement. Whilst the roller 10 fullows the straight
portion a bof the cam-groove, the forks have a rectilinear movement, whereas they

page_text: have a curvilinear movement whilst the roller follows the curve a c 3. This
D-shaped cam-groove gives excellent results, but its form may be modified
according to circumstances and the objects in view without departing from this
invention.
The mechanical parts just described may be arranged in any suitable wooden
casing or box provided with a small aperture at the top and at the bottom to allow
of the passage of the strip of sensitive film. Another aperture is provided in front
of the aperture 21 to allow the rays of light to impinge upon the sensitive plate.
On imparting rotary-motion to the shaft 1 by means of the handle, the lever 8
tends to impart to the arms 13 and 14 a rotary movement about their axis, but as
the roller 10 fixed to the arm 13 is engaged in the cavity of the cam 12, the
fork 13, 14 is compelled to follow the sinuous path by the cam-groove 12, and the
pointed parts 18 and 19 describe a curved path having a straight portion
corresponding to the distance between two consecutive holes in the strip.
We shall now proceed to describe the mode of working of our apparatus.
The strips of sensitive film are prepared and perforated beforehand. The holes
near each edge are placed at equal distances apart. They may be circular, but are
preferably of slightly oval form.
The end of the film is passed behind the roller 28 which serves as a guide, and
the film is pressed by means of the frame 22 in such a manner as to be gently held
whilst, however, being capable of sliding under the action of the claws 18 and 19.
as bereinafter described. Then the first two holes at the bottom are brought into
coincidence with the pointed parts 18 and 19.
If the apparatus be now set into motion by turning the crank 33, the claws will
describe a curve corresponding to that of the cam-groove and will consequently
strike against the film, and enter the holes provided for that purpose, at the instaut
that the roller 10 begins to engage in the straight portion of the D-shaped can-
groove. During the whole of the time that the roller follows the sail straight
portion, the claws will move in a straight line; they will then exert a pull on the
film and cause it to move forward up to the moment when the roller 10 enters the
curved portion of the D-shaped cam-groove. From that moment the claws leave
the film, which remains stationary until the roller, having moved through the
curve, returns into the straight portion of the D, and the claws act so as to move
the film forward again. The film has thus an intermittent motion imparted to it.
the period of rest being longer than that of motion. The film may as desired be
allowed to slide down to the bottom of the apparatus or be wound around the
drum 29.
The various parts of our apparatus are arranged in such a manner that the full
parts of the shutter 27 come in front of the aperture 21 whilst the film slides along
and moves longitudinally, whereas the openings of the shutter come in front of the
aperture 21 whilst the film is stationary and is exposed to the light. Consequently.
the sensitive film is acted upon by the light during the time it is stationary, the
rays of light being shut off by the shutter while the fiim is moving.
It will be readily understood that by means of our apparatus a series of instan-
taneous views may be taken of any object in motion at very short intervals of time
giving exposures however sufficiently long to produce very clear pictures.
One of the essential and characteristic features of our invention consists in our
having succeeded in imparting an intermittent movement to the film by means of a
regular and continuous rotary motion on the part of the remainder of the
apparatus, which is not interrupted during the stoppage of the film, whilst the
time during which the film is at rest is very much greater than the time during
which it is moving.
The straight portion of the cam-groove ensures that the motion of the film shall
be perfectly regular, and, as the holes pierced in the strip (Fig. 8) are slightly
larger than the diameter of the pointed parts, the consequence is that even if the
perforation were irregular to a certain extent, in eonsequence either of some fault
of the perforating machine or of the shrinkage of the film, that would not affect

page_text: the success of the photographs. The pointed parts enter the perforations and draw
down the film by bearing upon the lower edges of the perforations.
The engagement and disengagement of the pointed parts takes place always with
the geatest ease, whatever may be the speed of movement, and in a uniform manner
without the use of any special device.
The apparatus hereinbefore described may be employed, not only for taking
photographs of objects in motion, but also for projecting the same. For the latter
purpose it is sufficient to place in front of the aperture 21 an objective which will
magnify the photographs to the desired extent. The exposed film has imparted to
it a movement similar to that herein before described with respect to the sensitive
film, and the pictures are projected on to a screen.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. In apparatus. for taking and exhibiting series of photographs to represent
objects in motion comprising the combination with a shaft 6 arranged to be rotated
by a crank 33, of a slotted lever 8 in the slot of which is adapted to slide a
roller 9 revolving about a small shaft whose other end carries another and
similar roller 10 adapted to slide in the groove of a stationary cam 12, the form of
the said groove being such as to cause the roller 10 to have a rectilinear movement
followed by a curvilinear movement.
2. In an apparatus of the kind referred to, the combination of the shaft of the
rollers 9 and 10 with an arm 13 of a fork mounted on an axle 15 of a jointed
frame 16, which enables the successive rectilinear and curvilinear movements of
the roller 10 to be transmitted, by means of the arms 13 and 14 of the fork, to
pointed parts 18 and 19 fixed on the said arms.
3. An apparatus of the kind referred to in Claim 2, in which the successive
rectilinear and curvilinear movements of pointed parts 18 and 19, produced by
means of a cam of suitable form, are utilised for successively holding and releasing
the sensitive or exposed film by the said pointed parts, the said pointed parts
taking hold of the film by entering holes previously made in the edges of the film,
and continuing their hold thereof during the whole of their rectilinear movement,
the release of the film lasting during the whole of their curvilinear movement, and
the successive holding and release of the film corresponding respectively to the
movement and the stationary state of the film.
4. Our improved apparatus for taking and exhibiting photographs in series.
described with reference to and shown in the accompanying drawings.
Dated this 3rd December 1896.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.