Improvements in Photographic Shutters.
Year: 1896

page_text: Improvements in Photographic Shutters.
I, GAETAN JOSEPH FORTUNE MARIE MATTIOLI, of 7 Rue Broca, Paris, in
the Republic of France, Optician and Measuring Instrument Maker, do hereby
declare the nature of this invention to be as follows:-
This invention relates to photographic shutters, the various constituent parts of
which are so constructed and combined as to simplify the construction of the
operating mechanism, while at the same time reducing the space occupied by the
complete instrument.
The main features of my invention comprise the special arrangement and com-
bination of the mechanism for operating the shutters, the method of fixing the
instrument upon the hood of the object-lens, and the arrangement enabling the
admission of air to the apparatus to be regulated or controlled, in order to vary
the time occupied in opening and closing the shutters at will.
The invention will be best understood by reference to the accompanying
drawings, which are however, illustrated by way of example only; and in which
Figure 1 shows the internal arrangement of my improved apparatus with the
shutters closed;
Figure 2 is a similar view of the apparatus, but with the shutters open;
Figure 3 also illustrates the internal arrangement of the apparatus, the shutters
being here supposed to have been removed;
Figure 4 is a detail view of the shutters;
Figure 5 shows a modification of the apparatus ;
Figure 6 shows another modification of the same;
Figure 7 illustrates a further modification, with the shutters closed
Figure 8 shows the same form of apparatus as Figure 7, but with the shutters
open;
Figure 9 represents the same modification with the shutters removed;
Figure 10 is a vertical section of the arrangement whereby the air supplied to
the apparatus may be controlled at will;
Figure 11 is a horizontal section on line 1-2, Figure 10;
Figure 12 is a vertical section of the same arrangement;
Figure 13 is a vertical section on line 3-4 of Figure 12; and
Figure 14 is an elevation of the device for fixing the apparatus.
In all the figures, like letters of reference designate like parts.
In this improved shutter arrangement each shutter consists of two parts a¹, b¹,
and a², 63, slotted as shown in Figure 4 and pivotted at c', c² respectively.
The leaves or plates ba¹ and a 6, respectively which are adapted to slide over
each other, as illustrated in Figure 2, being mutually opened or spread out in
fan-shape when the shutters are actuated by a sliding device d', d'.
This arrangement enables the shutters to occupy a minimum space when open.
The two compound shutters formed by the plates a¹ b' and a³ 6² are arranged to
operate each other, each pair acting as a whole, for which purpose the plate a' is
provided with, or formed into, a fork, such as e, between the prongs or arms of
which is located the pin or pivot f, secured to the end of the heel-piece y with
which the plate a' is provided. The leaf or plate a¹ likewise carries a heel-piece h,
whereon the operating piston is intended to act in order to cause the shutters to

page_text: open. The plate al also carries a pin or pivot i which engages the fork ; forming
one of the arms of the bell-crank lever k, whereon the operating device is made to
act when the shutters are to be closed.
This operating device consists of a piston carrying a tappet at its end and
adapted to be set in operation by the compression of an india-rubber ball connected
by a flexible tube with the interior of the cylindrical body m wherein the said
piston is located.
When an exposure is to be made, the piston l, after having repelled the heel-
piece and thereby caused the shutters to open, must be arrested in its course by a
stop, the object of which is to prevent it from acting immediately upon the bell-
crank lever k. This stop is formed by the extremity of a lever p, pivotted at r,
and subjected to the action of a spring which constantly tends to move it into
contact with the pivot u. At a certain period of the operation, the lever p, being
required to move out of the way, in order to, allow the passage of the tappet l', is
removed by a lever n which acts upon it through the medium of a spring s, more
powerful than the spring t. This lever n, pivotted at q, is in turn operated by the
end of the bell-crank lever k, when, for the purpose of opening the shutters, such
lever kis turned about its pivot k³.
For instantaneous exposures, the lever p, is not required to detain the tappet l',
and therefore is kept entirely out of the way by the lever n, which, for this purpose,
will in its turn be repelled by the end of the bent rod v, suitably pivotted and
terminating in a milled head, whereby it may readily be operated by hand.
As shown in Figure 5, the bell-crank lever k is capable of acting upon the
lever p direct, for which purpose it here terminates in a flat spring s', which, when
the shutters are to be opened, presses upon the said lever p.
The lever p may, furthermore, be provided with a heel or tail-piece p' which, by
coming into contact with the wall of the apparatus, will arrest the movement of the
lever p and enable it to form a firm stop, when the bell-crank lever k is out of
engagement therewith.
The operation of the mechanism is as follows.
Supposing the shutter to be closed, as shown in Figure 1; then, if air under
pressure be forced into the cylinder m, the piston will be raised; and the tappet,
by coming into contact with the heel h, will turn the shutter a' on its pivot c¹, with
the result that the plate or leaf will also be turned on the pivot c'. This
movement will cause the fork e to act upon the pin f, and the shutters a² and 6 to
turn on the pivot ². The shutters a¹, b¹ and a³, 62, respectively, will then be found
to occupy the positions indicated in Figure 2. The tappet , after escaping from
contact with the heel h, will be arrested in its movement by the extremity of the
lever p, and will return to its initial position, as soon as the operator ceases to
compress the india-rubber ball.
In turning on its pivot el, the shutter, or portion of shutter, a', turns the bell-
crank lever on its pivot ', and the end of one of the arms of the same is thereby
caused to act upon the lever p, either directly (Figure 5), or through the medium
of the lever n (Figure 1), so as to prevent its further interference with the action
of the tappet l'.
When the time allotted for the exposure has elapsed, the operator presses the
indiaubber ball once more, to close the shutter. The piston forced up, as before,.
by the air under pressure, now acts upon the bell-crank lever k direct, causing it to
turn, on its pivot k', in the opposite direction, and thus to bring about the closure
of the shutters a', ' and a², 12.
For taking instantaneous views, it is merely necessary to turn the cranked rod v
so as to cause it to remove the lever p from the path of the tappet l' either direct
(Figure 5), or through the medium of the lever n (Figure 1), so that the piston /
shall be no longer prevented from making a full stroke.
The lever p, shown in Figures 3 and 5, may be substituted by a bell-crank
lever 2, as shown in Figure 6, subject to the action of the first mentioned bell-
crank lever k, which, in this case, is constructed in the shape of a cam k, adapted

page_text: to act upon a pin or stud p³, projecting from the end of the short arm of the lever p³.
The angular displacement of the lever p will,-when an exposure is made-be
limited by the striking of the pin p against a projection or shoulder, arranged at
the end of the arm v, pivotted at .
When the apparatus is in the position shown in Figure 6, (the position for
instantaneous work,) the piston 1, as previously explained, is the means whereby
the shutters are both opened and closed. The tappet , when it strikes the end
of the bell-crank lever p' in its upward movement, causes the said lever to turn
on its pivot in its movement, since there is no obstacle to prevent it from so doing.
For a time exposure, however, the arm is turned so that the shoulder ', is
caused to take up its position in the path of the pin p³. and thus limit the extent of
the angular displacement of the lever p, so that this lever, in turn, arrests the
tappet in its movement and so prevents it from acting upon the bell-crank lever k
immediately. When the shutters are closed, the cam k, hy pressing upon the
pin ³, will retain the long arm of the bell-crank lever p in the path of the spring-
tappet ; and as soon as the shutters open again, the bell-crank lever k will turn
on its pivot k¹, the result of such movement being that the cam k2 will release the
pin p, and the lever will yield to the pull of the spring t, so that the tappet
may be allowed to act upon the hell-crank lover k, as previously explained, when
the india-rubber ball is compressed.
Whether, therefore, a time or instantaneous exposure be desired, the apparatus
may be suitably set by the mere operation of the milled head terminating the
spindle, so that the shoulder v' is caused to arrest the action of the bell-crank
lever p, or not, as the case may be, when it is actuated by the piston l.
The two shutters may be exactly alike, as shown in Figures 7 and 8. Each
shutter, the constituent plates or leaves of which slide upon each other, as before
stated, is operated by a device such as ', . Each of these devices, or pieces, 4, 43,
which are pivotted at c', c², respectively, carries a stud 3, 4, extending through
the leaves a, a, so as to turn them as it moves; and is further provided with a
beel-piece, respectively, whereon the operating tappet is adapted to act when
the shutters are required to open. The piece h¹ is traversed by the stud or pin it
projecting from the bell-crank lever k, pivotted at kl, and the piece is similarly
traversed by the pin extending from the bell-crank lever, pivotted at . In
addition to this, the said lever & carries a second pin or stud k, which engages in
the fork el, terminating one of the arms of the bell-crank lever, for the purpose
of rendering the respective movements of the two shutters dependent on, or simul-
taneous with, each other. The stop p', pivotted at r, and intended to check the
motion of the operating tappet, is arranged and operated as stated above, being
subjected to the action of a flat spring t and controlled by the end of the long arm
of the bell-crank lever k acting upon the pin p3, which projects from the end of the
short arm of the said bell-crank lever p (Figure 9).
In the case of a time exposure, the lever p2 is arrested in its movement by a
stud carried by the rod v2.
This modification is operated as follows.
For instantaneous views, the tappet, by engaging the heel-pieces A, A, causes
the shutters to open, and the lever p to turn about its pivot, as it completes its
stroke, finally acting upon the bell-crank levers k, k, and thereby causing the
shutters to close.
For a time exposure, the rod v should first be turned in such a manner that the
stud may limit the extent of angular motion of the lever p; when this lover will,
in turn, arrest the operating tappet in its movement and so prevent its immediate
action upon the bell-crank levers k, k. Whilst the shutters are being opened, the
end of the lever k turns the lever, so that the free end of the latter is removed
from the path of the tappet . To close the shutters, it is necessary, as before
stated, to compress the indin-rubber ball, so as thereby to force the piston outward
and so cause the tappet to act directly upon the levers k and k³.
The opening and closing movements of the shutters are timed by means of a

page_text: special device enabling the admission of air into the cylinder m to be varied as
required (Figures 10 and 11).
The cylinder m is provided at its lower part with an internal collar m¹ having
apertures such as m² formed in it. Into this collar is screwed a length of tube w,
with which is connected the flexible tube communicating with the india-rubber
ball. This junction tube w, which has a central orifice w¹ at the top, and a suitable
number of orifices w2 in the sides, encloses a valve x in the sides of which, slots or
ports are provided for the passage of air. The central orifice w is directly
connected with the interior of the cylinder m, while the lateral orifices w² open
into the interior of a sleeve y which is screwed to the lower portion of the
cylinder m.
Air under pressure being admitted through the length of tube w raises the
valve, but cannot reach the interior of the cylinder m without passing through the
side orifices ¹, chamber y¹ and orifices m².
The speed of motion of the piston depends upon the volume of air admitted into
the cylinder m. It is therefore only necessary to screw or unscrew the sleeve y,
as the case may be, in order to reduce or increase the volume of the chamber y', and
therefore the quantity of air admitted into such chamber and the cylinder mat each
compression of the india-rubber ball; whereby, the time occupied in opening and
closing the shutters will be varied accordingly.
The sleeve y is graduated, and the divisions of the graduation correspond to the
varying volumes of the chamber y' and therefore, to the varying speeds of operation
of the mechanism, so that the division of the scale in front of a fixed index indicates
the corresponding length of time occupied by the opening and closing movements
of the shutters.
The time occupied by the shutters in opening and closing may be regulated by
the following mechanism, shown in Figures 12 and 13 which substantially consists
of a cock having a plug H which is provided with a circular groove I and an
orifice J, at both ends of which there open two narrow channels K. L, extending
round part of the periphery of the plug and the depth of which channels gradually
decreases, so that the sectional area of the aperture open for the passage of air
varies according to the position of the plug.
This plug is located within a bedy M provided with two sets of superposed
orifices, facing each other, as at O P Q R, one of these orifices R, being fitted with
a valve S.
The air, as it arrives through the pipe T, passes through the orifice O, then
through the port J in the plug, next through the orifice P into the cylinder m where
it actuates on the piston l.
According to the position of the plug H, or according as to whether the air is
allowed to pass through the port J direct, or is made to circulate through the
channels KL, the speed at which it is supplied will vary.
As soon as the india rubber ball is relieved from pressure, the air tends necessarily
to return to the ball with considerable speed, so that the said piston may immediately
return to its initial position. This quick return is obtained by the use of this
admission cock, for the air returns through the orifices P J O, and, in addition-
through the orifice Q, circular groove I and orifice R, thereby forcing the valve S
from its seat. The plug H carries a milled bead H, graduated on its periphery,
the division placed in front of the fixed index U indicating the corresponding
speed.
The apparatus is attached to the hood of the object-glass of the camera by the
tension of a flexible plate A one end of which is secured at a fixed point while the
other is connected with the end of a lever B pivotted at C and controllable by means
of the set-screw D (Figure 14).
In order to enable the arrangement to be firmly tightened, I have devised a
special method for the attachment of the flexible plate A to the lever B. This
plate A, which extends around the pins E set in the periphery of the aperture F
of the apparatus, passes round the lever B and over a pin G, in such a manner that

page_text: even a slight displacement of the lever may powerfully stretch or strain the
plate A.
This
Thus by operating the screw D, and so forcing the lever B to turn on its pivot C
the tension of the said plate A may be increased or reduced. The consequence will
be a more or less close adhesion of the apparatus to the hood of the camera.
arrangement also enables my improved apparatus or attachment to be fitted to
object-glasses of various diameters.
The shutter arrangement may be protected, or covered in, by a plate of glass or
any other suitable transparent material, thus exposing the internal mechanism to
view.
It will be understood that the several improvements herein described are
applicable to existing shutters of every description, either singly or in combination;
while the details of construction and arrangement may vary according to
requirements without any departure from the principle of the invention.
Dated this 2nd day of June 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
I, GAETAN JOSEPH FORTUNE MARIE MATTIOLI, of 7 Rue Broca, Paris, ia
the Republic of France, Optician and Measuring Instrument Maker, 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 relates to photographic shutters, the various constituent parts of
which are so constructed and combined as to simplify the construction of the
operating mechanism, while at the same time reducing the space occupied by the
complete instrument.
The main features of my invention comprise the special arrangement and
combination of the mechanism for operating the shutters, the method of fixing the
instrument upon the hood of the object-lens, and the arrangement enabling the
admission of air to the apparatus to be regulated or controlled, in order to vary
the time occupied in opening and closing the shutters at will.
The invention will be best understood by reference to the drawings accompanying
my Provisional Application, which are however, illustrated by way of example only
and in which
Figure 1 shows the internal arrangement of my improved apparatus with the
shutters closed;
Figure 2 is a similar view of the apparatus, but with the shutters open;
Figure 3 also illustrates the internal arrangement of the apparatus, the shutters
being here supposed to have been removed
Figure 4 is a detail view of the shutters;
Figure 5 shows a modification of the apparatus ;
Figure 6 shows another modification of the same;
Figure 7 illustrates a further modification, with the shutters closed;
Figure 8 shows the same form of apparatus as Figure 7, but with the shutters
open;
Figure 9 represents the same modification with the shutters removed;
Figure 10 is a vertical section of the arrangement whereby the air supplied to
the apparatus may be controlled at will;

page_text: Figure 11 is a horizontal section on line 1-2, Figure 10;
Figure 12 is a vertical section of the same arrangement;
Figure 13 is a vertical section on line 3-4 of Figure 12; and
Figure 14 is an elevation of the device for fixing the apparatus.
In all the figures, like letters of reference designate like parts.
In this improved shutter arrangement each shutter consists of two parts a', b',
and a², 2, slotted as shown in Figure 4, and pivotted at c', c respectively.
The leaves or plates 1, a' and a² 2, respectively which are adapted to slide over
each other, as illustrated in Figure 2, being mutually opened or spread out in
fan-shape when the shutters are actuated by a sliding device d', d².
This arrangement enables the shutters to occupy a minimum space when open.
The two compound shutters formed by the plates a', b' and a², 62 are arranged to
operate each other, each pair acting as a whole, for which purpose the plate al is
provided with, or formed into, a fork, such as e, between the prongs or arms of
which is located the pin or pivot f, secured to the end of the heel-piece g with which
the plate a is provided. The leaf or plate a¹ likewise carries a heel-piece h,
whereon the operating piston is intended to act in order to cause the shutters to
open. The plate a¹ also carries a pin or pivot i which engages the fork j forming
one of the arms of the bell-crank lever k, whereon the operating device, is made to
act when the shutters are to be closed.
This operating device consists of a piston carrying a tappet at its end and
adapted to be set in operation by the compression of an india-rubber ball connected
by a flexible tube with the interior of the cylindrical body m wherein the said
piston is located.
When an exposure is to be made, the piston l, after having repelled the
heel-piece h and thereby caused the shutters to open, must be arrested in its course
by a stop, the object of which is to prevent it from acting immediately upon the
bell-crank lever k. This stop is formed by the extremity of a lever p, pivotted at r,
and subjected to the action of a spring t which constantly tends to move it into
contact with the pivot u. At a certain period of the operation, the lever p, being
required to move out of the way, in order to allow the passage of the tappet , is
removed by a lever n which acts upon it through the medium of a springs, more
powerful than the spring t. This lever n, pivoted at y, is in turn operated by the
end of the bell-crank lever k, when, for the purpose of opening the shutters, such
lever kis turned about its pivot k¹.
For instantaneous exposures, the lever p, is not required to detain the tappet,
and therefore is kept entirely out of the way by the lever n, which, for this
purpose, will in its turn be repelled by the end of the bent rod v, suitably pivotted
and terminating in a milled head, whereby it may readily be operated by hand.
As shown in Figure 5, the bell-crank lever k is capable of acting upon the lever p
direct, for which purpose it here terminates in a flat spring which, when the
shutters are to be opened, presses upon the said lever p.
The lever p may, furthermore, be provided with a heel or tail-piece p' which, by
coming into contact with the wall of the apparatus, will arrest the movement of the
lever p and enable it to form a firm stop, when the bell-crank lever k is out of
engagement therewith.
The operation of the mechanism is as follows.
Supposing the shutter to be closed, as shown in Figure 1, then, if air under
pressure be forced into the cylinder m, the piston I will be raised; and the tappet l',
by coming into contact with the heel h, will turn the shutter a' on its pivot c', with
the result that the plate or leaf will also be turned on the pivot c'. This
movement will cause the fork e to act upon the pin, and the shutters a² and 6 to
turn on the pivot c. The shutters a', 6' and a², 63, respectively, will then be found
to occupy the positions indicated in Figure 2. The tappet l', after escaping from
contact with the heel h, will be arrested in its movement by the extremity of the
lever p, and will return to its initial position, as soon as the operator ceases to
compress the india-rubber ball.

page_text: In turning on its pivot c', the shutter, or portion of shutter, a¹, turns
the bell-crank lever k on its pivot k', and the end of one of the arms of the
same is thereby caused to act upon the lever p, either directly (Figure 5), or
through the medium of the lever n (Figure 1), so as to prevent its further
interference with the action of the tappet 1.
Z
When the time allotted for the exposure has elapsed, the operator presses the
india-rubber ball once more, to close the shutter. The piston 7 forced up, as before,
by the air under pressure, now acts upon the bell-crank lever direct, causing it to
turn, on its pivot k, in the opposite direction, and thus to bring about the closure
of the shutters a', ' and a², ².
For taking instantaneous views, it is merely necessary to turn the cranked rod »
so as to cause it to remove the lever p from the path of the tappet I, either direct
(Figure 5), or through the medium of the lever n (Figure 1), so that the piston
shall be no longer prevented from making a full stroke.
The lever p, shown in Figures 3 and 5, may be substituted by a bell-crank
lever p3, as shown in Figure 6, subject to the action of the first mentioned bell-crank
lever k, which, in this case, is constructed in the shape of a cam k2, adapted to act
upon a pin or stud p³, projecting from the end of the short arm of the lever p
The angular displacement of the lever 2 will, when an exposure is made, be
limited by the striking of the pin p3 against a projection or shoulder v¹, arranged
at the end of the arm e, pivoted at 2.
When the apparatus is in the position shown in Figure 6, (the position for
instantaneous work), the piston 1, as previously explained, is the means whereby
the shutters are both opened and closed. The tappet , when it strikes the end
of the bell-crank lever p³ in its upward movement, causes the said lever to turn on
its pivot since there is no obstacle to prevent it from so doing.
For a time exposure, however, the arm v is turned so that the shoulder v', is.
caused to take up its position in the path of the pin p3, and thus limit. the extent
of the angular displacement of the lever p², so that this lever, in turn, arrests the
tappet in its movement and so prevents it from acting upon the bell-crank lever k
immediately. When the shutters are closed, the cam k2, by pressing upon the
pin p³, will retain the long arm of the bell-crank lever p in the path of the spring-
tappet ; and as soon as the shutters open again, the bell-crank lever k will
turn on its pivot k', the result of such movement being that the cam k² will release
the pin p, and the lever p² will yield to the pull of the spring t', so that the
tappet may be allowed to act upon the bell-crank lever k, as previously explained,.
when the india-rubber ball is compressed.
Whether, therefore, a time or instantaneous exposure be desired, the apparatus
may be suitably set by the mere operation of the milled head terminating the
spindle v², so that the shoulder ol is caused arrest action of the bell-crank lever p,
or not, as the case may be, when it is actuated by the piston l.
The two shutters may be exactly alike, as shown in Figures 7 and 8. Each
shutter, the constituent plates or leaves of which slide upon each other, as before
stated, is operated by a device such as h³, h². Each of these devices, or
pieces, 1, 1, which are pivotted at c', c2, respectively, carries a stud ³, 1,
extending through the leaves a', a², so as to turn them as it moves; and is further
provided with a heel-piece h, respectively, whereon the operating tappet is
adapted to act when the shutters are required to open. The piece is traversed
by the stud or pin ", projecting from the bell-crank lever k, pivotted at ', and the
piece is similarly traversed by the pin extending from the bell-crank lever k³,
pivotted at k. In addition to this, the said lever k carries a second pin or stud k³,
which engages in the fork e', terminating one of the arms of the bell-crank lever 3,.
for the purpose of rendering the respective movements of the two shutters
dependent on, or simultaneous with, each other. The stop p³, pivotted at r, and
intended to check the motion of the operating tappet, is arranged and operated as
stated above, being subjected to the action of a flat spring t¹ and controlled by the
end of the long arm of the bell-crank lever k acting upon the pin p³, which

page_text: projects from the end of the short arm of the said bell-crank lever p³
(Figure 9).
In the case of a time exposure, the lever p³ is arrested in its movement by a
carried by the rod ².
stud
This modification, is operated as follows.
For instantaneous views the tappet, by engaging the heel-piece h, h, causes the
shutters to open, and the lever p to turn about its pivot, as it completes its
stroke, finally acting upon the bell-crank levers k, 3, and thereby causing the
shutters to close.
For a time exposure, the rod 2 should first be turned in such a manner that the
stud may limit the extent of angular motion of the lever p²; when this lever
will, in turn, arrest the operating tappet in its movement and so prevent its
immediate action upon the bell-crank levers k, k³. Whilst the shutters are being
opened, the end of the lever k turns the lever p, so that the free end of the latter
is removed from the path of the tappet . To close the shutters, it is necessary,
as before stated, to compress the india-rubber ball, so as thereby to force the
piston outward and so cause the tappet to act directly upon the levers k, and k³.
The opening and closing movements of the shutters are timed by means of a
special device enabling the admission of air into the cylinder m to be varied as
required, (Figures 10 and 11).
The cylinder m is provided at its lower part with an internal collar m¹ having
apertures such as m² formed in it. Into this collar is screwed a length of tube w
with which is connected the flexible tube communicating with the india-rubber
ball. This junction tube w, which has a central orifice w¹ at the top, and a suitable
number of orifices w² in the sides, encloses a valve in the sides of which, slots or
ports are provided for the passage of air. The central orifice w is directly
connected with the interior of the cylinder m, while the lateral orifices w² open
into the interior of a sleeve y which is screwed to the lower portion of the
cylinder m.
Air under pressure being admitted through the length of tube w raises the
valve, but cannot reach the interior of the cylinder m without passing through
the side orifices a¹, chamber y' and orifices m².
The speed of motion of the piston depends upon the volume of air admitted
into the cylinder m. It is therefore only necessary to screw or unscrew the
sleeve y, as the case may be, in order to reduce or increase the volume of the
chamber y', and therefore the quantity of air admitted into such chamber and
the cylinder m at each compression of the india-rubber ball; whereby the time
occupied in opening and closing the shutters will be varied accordingly.
The sleeve y is graduated, and the divisions of the graduation correspond to the
varying volumes of the chamber y and, ther. fore, to the varying speeds of operation
of the mechanism, so that the division of the scale in front of a fixed index
indicates the corresponding length of time cccupied by the opening and closing
movements of the shutters.
The time occupied by the shutters in opening and closing may be regulated by
the following mechanism, shown in Figures 12 and 13 which substantially consists
of a cock, having a plug H which is provided with a circular groove I and an
orifice J, at both ends of which there open two narrow channels K L, extending
round part of the periphery of the plug and the depth of which channels gradually
decreases, so that the sectional area of the apertures open for the passage of air
varies according to the position of the plug.
This plug is located within a body M provided with two sets of superposed
orifices, facing each other, as at O P Q R, one of these orifices R, being fitted with
a valve S.
The air, as it arrives through the pipe T, passes through the orifice O, then
through the port J in the plug, next through the orifice P into the cylinder m
where it actuates on the piston l.
According to the position of the plug H, or according as to whether the air is

page_text: allowed to pass through the port J direct, or is made to circulate through the
channels KL, the speed at which it is supplied will vary.
As soon as the india-rubber ball is relieved from pressure, the air tends necessarily
to return to the ball with considerable speed, so that the said piston may immediately
return to its initial position. This quick return is obtained by the use of this
admission cock, for the air returns through the orifices P, J, O, and, or in addition
-through the orifice Q, circular groove I and orifice R, thereby forcing the
valve S from its seat. The plug H carries a milled head H', graduated on its
periphery, the division placed in front of the fixed index U indicating the
corresponding speed.
The apparatus is attached to the hood of the object-glass of the camera by the
tension of a flexible plate A one end of which is secured at a fixed point while the
other is connected with the end of a lever B pivotted at C and controllable by
means of the set-screw D. (Fig. 14.)
In order to enable the arrangement to be firmly tightened, I have devised a
special method for the attachment of the flexible plate A to the lever B. This
plate A, which extends around the pins E set in the periphery of the aperture F
of the apparatus, passes round the lever B, and over a pin G, in such a manner
that even a slight displacement of the lever may powerfully stretch or strain the
plate A.
Thus by operating the screw D, by forcing the lever B to turn on its pivot C,
the tension of the said plate A may be increased or reduced. The consequence
will be a more or less close adhesion of the apparatus to the hood of the camera.
This arrangement also enables my improved apparatus or attachment to be fitted
to object-glasses of various diameters.
The shutter arrangement may be protected, or covered in, by a plate of glass or
any other suitable transparent material, thus exposing the internal mechanism to
view.
It will be understood that the several improvements herein described are applicable
to existing shutters of every description, either singly or in combination; while
the details of construction and arrangement may vary according to requirements
without any departure from the principle of the invention.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improved photographic shutter arrangement, characterized by the special
combination and arrangement of the means for operating the shutters, the device
for controlling the admission of air to the apparatus, so as to vary the time taken
up in opening or shutting the shutters at will, and the method of attachment
of the improved mechanism to the hood of the object-lens of the camera.
2. The employment of these improvements in existing shutters of every
description either singly or in combination.
3. The complete apparatus described, or any one or more of its constituent
parts, all substantially as and for the purpose specified and illustrated in the
accompanying drawings.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.