Improvements in Photographic Hand Cameras.
Year: 1889

page_text: Date of Application, 1st Apr., 1889
Complete Specification Left, 19th Dec., 1889-Accepted, 15th Feb., 1890
PROVISIONAL SPECIFICATION.
Improvements in Photographic Hand Cameras.
DENIS MCNAMARA 25 South Terrace Inchicore Dublin Engine Fitter I do hereby
declare the nature of this invention to be as follows :-
Its novel features are (First) A dry plate is changed and placed in focal position
and the shutter set, by the one movement, thereby preventing the possibility of
exposing the same plate twice over through inadvertence or otherwise (secondly)
The one button or knob serves all purposes viz., for changing dry plate, for setting
and discharging the shutter. Hence the advantage by which a number of dry plates
may be exposed in very rapid succession.
In outward shape it consists of a rectangular box or case, one end of which is
recessed to received the lens. Within said case is a grooved box open at the side
next to the lens, its depth a little more than double that of the sensitized plates of
which it is capable of holding 12 or more each of the latter is inserted in a thin
metallic sheath, midway on the inside of the two opposite walls of said box is formed
a horizontal groove parallel to the axis of the lens through which is passed a thin
metallic plate or partition dividing it into two compartments, the upper for the
unexposed and the lower for the exposed plates and on which it is capable of sliding,
the ends of said partition are attached to the walls of outer casing and a slot is cut in
the former sufficiently large to allow one plate with its sheath to drop through at a
time from top to bottom compartment. Immediately beneath partition and in said
bottom compartment is a rod one end crossing said slot so as to prevent a plate from
dropping through and is kept in position by a. spiral spring, the other end passes
through wall of outer case at the end opposite to the lens and terminates in a joint
to which is attached a lover actuated by a bar placed longitudinally on the outside of
camera ono end bearing at right angles against said lever, the other terminates in a
knob or button which is used for setting and discharging the shutter and also for
changing the dry plates. On the bottom of the outer case is a sliding cover through
which the grooved box is charged with dry plates. In doing so the plates are placed
in their grooves in the lower chamber the camera being inverted according as grooved
box is moved along the partition each time a plate comes over the said slot it drops
through into the upper compartment the rod being kept back so as to clear the
slot by pressing upon the knob during this operation.
The instantaneous shutter is inside the camera. A nozzle or rim is formed at the
back of the lens on which is fitted a cap capable of opening by a hinged joint at the
bottom and actuated by a spindle one end of which passes through the outer wall of
camera terminating in a cross piece forming a T with said spindle. At one end of
said cross piece at right angles to it and parallel with wall of outer case is secured
or formed a thin flexible arm of spring steel, the end of said arm resting upon a ledge
or stud when the shutter is closed, the other end of cross piece forming a crank with
said spindle is used for the purpose of opening the cap by means of a hook hinged on
to a sleeve and kept in position by a flat spring. Said sleeve is capable of sliding
upon the bar to which is attached knob or button heretofore mentioned and is actuated
by a spiral spring slipped over said bar, one end bearing against the sleeve, the other
against a movable pin for regulating the speed of the shutter. When said bar is
pushed forward by the knob the sleeve and hook are carried with it the spiral spring
becomes compressed the hook coming into contact with cross piece and having a
wedge shaped end loops on to it, when the finger is removed from said knob the latter
returns to its original position being acted upon by the spiral spring in grooved box
the hook retaining its hold upon the cross piece, the shutter is now set.

page_text: To discharge the shutter, the knob is pushed in the opposite direction thereby
bringing a thin flat projecting piece secured to said bar into contact with flexible arm
resting upon projecting ledge which yields by, its flexibility and is pushed off said
ledge the spiral spring now acting on the hook shoots it forward thereby turning
round, the cross piece with it and opening.the cap when. said cross: piece arrives at a
certain angle the hook slips off but the momentam imparted to the cap causes the
latter to strike an elastic band or spring which causes it to rebound and lock itself
once more on projecting ledge.
To change a plate, the knob is pushed forward the shutter becomes set as before
the bar bearing against the end of lever draws out the rod in grooved box and a plate
is dropped into bottom compartment, the pressure of the finger is now removed from
said knob and the spiral spring brings back said rod into its original position but the
latter when returning comes into contact with the top edge of plate which has just
dropped and pushes it forward and being in its groove it carries the entire grooved
box along the sliding partition until the next plate following up drops a short distance
down into slot in partition and rests on top of rod said plate becomes jammed in
the slot by the pressure of the rod still bearing on top edge of, plate in bottom
compartment thereby keeping the plate steady for exposing.
The plates when dropping would be liable to stick after being jammed. in the
manner described. To overcome this, the partition where it is attached at both ends
to camera is made to slide longitudinally through a short distance. A lever is hinged
on inside to wall of camera one end bearing against a stud on partition the other end
against a similar stud on rod, when the latter is drawn out the said lever moves the
partition the grooved box remaining stationary and liberates the plate which. had
been jammed in the slot thereby allowing it to drop freely said partition being
brought back again to position by a spring.
An indicator is attached to camera for the purpose of registering, the number of
exposed plates. It consists of a flat graduated bar connected to grooved, box and
capable of moving in a guide on the inside of camera with a hole in the latter
forming light tight communication with said guide and' through which the number
of exposed plate can be read from the outside."
Dated this 30th day of March 1889..
COMPLETE SPECIFICATION.
Improvements in Photographic Hand Cameras:
DENIS MCNAMARA 25 South Terrace Inchicore Dublin Engine Fitter 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:
My invention consists of a Photographic Detective or Hand Camera the construction
of which is illustrated in the accompanying drawing. aa Figs. 1. 2. & 3 is a rectangular
box or case represented in wood but it may also be of sheet metal or other material.
ss is a recess formed out of thin sheet metal and secured on the inside to one end of
said case, with a corresponding hole in the latter through which the lens 0, is inserted
into said recess from the outside. Within the outer case is a grooved box bbb i bl
with its depth a little more than double that of the sensitized plates of which it is capable
of holding 12. Each of the latter is inserted in a thin metallic sheath, see Fig 7.
Midway on the inside of each of the two opposite walls of said box is formed, longi-
tudinally, a groove through which is passed a thin metallic flanged plate or partition cc,
dividing it into two compartments the upper for the unexposed and the lower for the
exposed plates and on which it is capable of sliding, the said upper, compartment is
left open at the end next to lens so as to admit the light from the latter to the
sensitized film.

page_text: A slot is cut in said partition at the focal distance from the lens sufficiently
largo to allow one plate with its sheath at a time to drop through from top to bottom
compartment. Immediately beneath partition is a rod d capable of moving in a
guide U with one end crossing said slot, the other end terminates in a joint, which
is attached to the lever Q, the latter is hinged at D to the said partition the opposite
end coming into contact at about right angles with the hollow bar G placed longi-
tudinally inside the wall of outer casing, the front end of said bar passes through
the light tight guide M and into the recess opening to the outside of camera, the
said recess is formed out of thin sheet metal and inserted in a hole cut in the wall of
outer casing. To the end of hollow bar is attached an angle shaped piece of thin
sheet metal fitting over said recess thereby forming a sliding cover for same. A
notch is cut near N for the purpose of giving a hold for the fore finger and thumb
for moving said slide back or forward when manipulating the shutter or changing the
dry plates, the rod d, and hollow bar are actuated by the spiral spring placed in the
barrel A the latter being secured to the lever and flanged inwards at one end to
prevent said spring from being forced through by the collar B, of a spindle which is
bearing against it one end of said spindle coming into contact with back wall of outer
casing. The instantaneous shutter is inside the camera. A nozzle or rim is formed
at the back of the lens on which is fitted a cap e capable of opening at the bottom
by means of the spindle V to which said cap is attached at one end, the other end of
said spindle passes through a long bearing W and into the recess r, and terminates
in a cross piece E (see Fig. 8, with the inside reversed or turned outwards) to a
portion of which is attached or formed a thin elastic arm a resting upon a ledge, the
other end of said cross piece forming a bell crank with the spindle V, and is used for
the purpose of opening the cap e, by the hook L hinged on to a cylindrical shaped
slide K capable of moving inside the hollow bar G. A slot is cut in the latter through
which passes a projection formed on said slide and to which the said hook is attached.
A spiral spring H is placed inside the hollow bar one end bearing against the slide K
the other end against a pin n (Fig. 9) movable in the slot m for regulating the speed of
the shutter, said pin coming into contact with a fork to which is attached a light
tight slide the latter having two projections (see Fig. 9) passing through a slot cut in
the bottom of a recess, the screwed rod T (Figs. 3 & 4) being secured at both ends
to said recess, with a milled nut u fitting thereon, the under portion of the latter
passing between the projections at the bottom of recess is capable of carrying them
with it when turning the milled nut together with the fork to which they are
attached thereby varying the tension of the spiral spring H and consequently the
rapidity of the shutter. An indicator is attached to the camera for the purpose of
registering the number of plates exposed. It consists of a flat graduated bar
connected to grooved box and capable of moving with the latter through a light
tight sleeve said bar passing over an aperture cut in the outer casing through
which the number of exposed plates can be read from the outside.
The Camera is manipulated in the following manner. When the hollow bar G
is pulled back by pressing on the sliding cover at N the hook L is carried with it and
the inclined plane portion of the latter coming into contact with the outside of bell
crank causes it to loop thereon by the assistance of the flat spring g. At the same
time the rod d is drawn out by the action of the lever Q and the plate resting thereon
(which we will say has already been exposed) drops with its sheath into bottom com-
partment, the pressure is now released at N and the spiral spring in the barrel A
acting upon the lever causes both the hollow bar G and rod d to return to their
original positions, but when returning the front end of the latter comes into contact
with the top edge of the plate which has just dropped and pushes it forward, and as
cach plate is in a separate groove it carries the entire grooved box along the sliding
partition together with the remainder of the unexposed plates resting thereon until
the plate next to the one just released coming over the slot of drops a short distance
into the latter and rests on the spindle d. where it is held rigidly in position for
exposure, by the rod still pressing on the top edge of plate in bottom compartment
(see Fig. 1). At the same time the hollow bar G when returning leaves the hook L

page_text: ooped onto the bell crank arm and the shutter is set. To release the shutter the
sliding cover N is pushed or moved a short distance in the opposite direction thereby
bringing a thin flat projecting piece Z secured to the hollow bar into contact with the
elastic arm a resting upon the ledge (see Fig. 8) the said arm yields by its elasticity
and is pulled off the said ledge the spiral spring H being now released acting upon
the hook L shoots it forward thereby turning round the bell crank arm, when the latter
arrives at a certain angle the hook slips off but the momentum imparted to the cap
or shutter (which by the action of the bell crank has been opened) causes it to strike
the elastic band y from which it rebounds and closes again, at the same time the
elastic arm g becomes latched on top of the projecting piece Z, by releasing the fingers
from N the small spiral spring at one end of the hollow bar draws back the latter to
its original position leaving the elastic arm resting upon the ledge, a pin is inserted
at the back of said spring so as to hold it in its place, it also acts as a stop for hollow
bar when discharging the shutter, the end of the bar passing through a bracket or
guide secured to the side of outer casing at this point (see Fig. 3). The action of
drawing back the rod, d from beneath the sensitized plate is not at all times sufficient
to drop the latter without tilting the camera, as the front side of the slot, which
had previously jammed the plate-so as to hold it steady for exposure-is still in
contact with it, in order to overcome this, the sliding partition has about 1 of an inch
of play longitudinally in the supports CCC, so that when the rod, d is drawn back,
the spiral spring acting as a fulcrum to the lever, Q, causes the end D (Fig. 3) to
move the sliding partition a little forward, the grooved box remaining stationary as it
is resting on the bottom of outer casing which is a sliding cover hereinafter to be
described. By this means the sensitized plate becomes liberated and drops freely into
the bottom compartmont, when the rod, d, has returned to its original position, the
slotted link R connected to the joint h and the back wall of casing-holds it in check,
tho said slotted link becomes the fulcrum to the lever Q, the spiral spring acting upon
the lever causes the end, D to move the partition back to its original position.
A slot is cut in a portion of ono side of the grooved box to allow the lever to pass
through.
The sliding cover on the bottom of outer casing already refered to, is used for
the purpose of giving access to the interior when charging or removing the dry plates.
The latter are placed in the grooves in the bottom compartment-the camera being
inverted and are dropped one by one through the slot, into the top compartment,
the rod, d being held back during the operation. J (Fig. 10) is a small indiarubber
washer against which the slide K strikes at the moment of exposure, and is used to
provent vibration in the camera.
Having now particularly described and ascertained the nature of my said
invention and in what manner the samo is to be performed, I declare that what I
claim is
(1) The Instantaneous shutter, comprising the mechanism for setting, releasing,
and regulating the rapidity of the shutter and the action thereof described and
illustrated in the foregoing.
(2) The arrangement for automatically changing the sensitized plates and the
working thereof in conjunction with the mechanism employed in setting the shutter
so that both are effected by the one movement of the button or trigger, comprising a
flanged metallic plate or partition passing longitudinally through the centre of the
grooved box dividing it into two compartments, the upper for the unexposed and the
lower for the exposed plates and on which said box is capable of sliding, with a
transverse slot in said partition at the focal distance of the lens through which each
plate is dropped after exposure into bottom compartment, the partition having about
Te of an inch of play longitudinally on supports attached to the end walls of outer
casing, a lever is hinged at one end to partition, the other end comes in contact with
one extremity of the hollow bar G, the rod d-for dropping the plates-is jointed
at to the said lever, the opposite end crosses the transverse slot fin and upon which
a plate is held when in focal position, a spiral spring is connected to the lever to

page_text: impart a return motion to the latter and hollow bar after dropping a plate it also
serves as a fulcrum to the lever when drawing out the rod, d, by which the partition
is moved forward to facilitate the dropping of the plates. In the return motion the
spiral spring is the motive power and throws the fulcrum on to a link R by which
the partition is moved back to its original position, the top edge of a plate when
dropped into bottom compartment acts as a support to the end of rod d to bring the
next plate into focal position.
Dated this 17th day of December 1889