Improvements in Photographic Cameras.
Year: 1889

page_text: Date of Application, 26th Sept., 1889
Complete Specification Left, 26th July, 1890-Accepted, 13th Sept., 1890
PROVISIONAL SPECIFICATION.
Improvements in Photographic Cameras.
I ABRAHAM DIRK LOMAN of 361, N. Z. Voorburgwal Amsterdam in the Kingdom
of the Netherlands Manufacturer do hereby declare the nature of this invention to be
as follows:-
The object of my invention is so to construct and fit and with such appliances
photographic cameras and especially hand or portable cameras that the object can very
easily be exactly focussed that the longest or the shortest desired exposure can be
given to the sensitive plate therein and that no vibration will be given to the camera
by such exposure or that is to say by such movements of those parts in this camera
that allow the exposure and I realize all these advantages in a very simple and effective
manner.
To carry out this object the camera forms or is placed in a preferably rectangular
casing of the desired size one end whereof or part of the same may be open or capable
of being opened and the lens is placed at or near this opening preferably being
mounted as is usual in a tube and when the lens is behind the opening this tube can
he secured in and to a partition placed transversely in the casing and a rack and
pinion movement is provided which can be operated from outside the casing and by
which this partition may be moved or the tube may be elongated or shortened to
bring the object into focus and suitable stops preferably diaphragmatic may be fitted
to the lens or to the lens tube. When the partition is to be so moved suitable opaque
bellows can very conveniently be fitted between and to the opening of the casing and
the partition round the lens tube to make this partition light tight.
The proper
distance behind the lens is horizontally and transversely pivoted in the casing and
near the upper part of the same by its upper and further edge a mirror corresponding
wherewith a piece of ground glass is inserted into the top of the casing and this
mirror when inclined downwards at the proper angle receives the image through and
from the lens and transmits it to the ground glass. The mirror and the ground
glass are suitably surrounded by opaque bellows and when the same are extended an
opening made in the front part thereof corresponds with the lens. Below the mirror
is fitted in the casing an india rubber pocket or other pneumatic bellows which can
he operated from outside the casing by a collapsible ball and is connected by a link
or otherwise with the mirror in such wise that when and as the same is distended
the mirror is folded up against and parallel or thereabouts with the ground glass.
Bohind the mirror is inserted in the casing the dark slide that holds the sensitive
plate or plates. All these parts are so arranged that when the image has been
focussed on the ground glass it will also be exactly in focus on the sensitive plate
or a certain predetermined movement must be given as aforesaid to the lens whereby
it is known this exact focussing will be effected. Any suitable shutter may be used
in and with this camera that will give a timed or an instantaneous exposure as may
be desired and I preferably use what is known as a blind shutter placed behind the
mirror and immediately before the sensitive plate and more especially the blind shutter
that is described in the Provisional Specification accompanying another application
for a patent which I have made this day.
The method of using this camera is as follows. When the image has been duly
focussed on the ground glass and the known correction if any has been duly applied
to such focussing and the sensitive plate has been placed in position and uncovered if
timed exposure is required the shutter is properly arranged therefor and then by
E pneumatic bellows the mirror is raised and the required exposure is given to the
sensitive plate when the pressure is removed and the mirror is allowed to regain its
normal position being assisted therein if desired by a spring but if an instantaneous

page_text: exposure is required the shutter also is properly arranged therefor and then in the
same manner the mirror is raised until it comes in contact with a spring or catch or
other appliance which when pressed will allow or cause the shutter to act and give the
required exposure.
Instead of inserting the ground glass as aforesaid into the top of the casing I may
when I so desire insert the same into one of the sitles of the casing moving the
other parts of this camera where necessary into the proper corresponding relative
positions.
COMPLETE SPECIFICATION
Improvements in Photographic Cameras.
I ABRAHAM DIRK LOMAN of 361, N. Z. Voorburgwal Amsterdam in the Kingilom
of the Netherlands Manufacturer do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :—
The object of this my invention is so to construct and so to fit and with such
sappliances photographic cameras and especially hand or portable cameras that the
object can very easily be properly and exactly focussed that the longest or the
shortest desired exposure can be given to the sensitive plate therein and that little or
no vibration will be given to the camera by such exposure or that is to say by such
movements of those parts in this camera that allow or effect the exposure and I realize
all these advantages in a very simple but efficient manner.
In order the more clearly to explain this my invention and in what manner the
same is to be performed I refer to the accompanying drawing wherein Figure 1 is
a side elevation partly in section of a photographic camera constructed and fitted
according to my invention with the side of the casing thereof removed and Figure 2
is a transverse section of the same taken at a bin Figure 1.
The camera forms or is placed in a preferably rectangular casing A of the desired
size one end B whereof may be open or he capable of being opened and the lens is
placed at or near this opening B preferably mounted as is usual in a tube Cand when
the lens as is most convenient is behind the opening B this tube C can be secured in
and to a partition 1) placed transversely in the casing A and a rack and pinion
movement D is provided which can be operated from outside the casing A and by
which this partition D may be moved to bring the object into focus or the tube C
may be elongated or shortened for the same purpose in any usual and convenient
manner in which case the partition D could be a fixture or the partition D could be
dispensed with and the tulie C secured to the casing A round the opening B therein
and suitable stops preferably diaphragmatic may be fitted to the lens or to the lens
tube.
When the partition D is a movable one suitable opaque bellows E can very
conveniently be fitted to and between the casing A round the opening B and the
partition Dround the lens tube C to make this partition D light tight. The proper
distance behind the lens a mirror F secured in a suitable framing is horizontally and
transversely pivoted at F in the casing A near the upper part thereof by its upper
and further edge corresponding with which mirror F a piece of ground glass G is
inserted into the top of the casing A and when this mirror F is inclined downwards
at the proper angle as is shown in Figure 1 to receive the image through and from
the lens and transmit the same to the ground glass G it rests on suitable
brackets H and H. The mirror F and the ground glass G are properly surrounded
by opaque bellows K in the front part whereof an opening K' is made which corre-
sponds with and is opposite to the lens when the bellows are extended. Behind the
mirror a space L is made in the casing A wherein the dark slide that holds the
sensitive plate or plates can be inserted. All these parts are so arranged that when
the image has been focussed on the ground glass it will also be in focus on the

page_text: sensitive plate or a certain predetermined movement must be given in manner afore-
said to the lens whereby it is known that this exact focussing will be effected. Any
suitable shutter may be used in and with this camera preferably one that will give a
timed or prolonged or an instantaneous exposure as may be desired but I consider
the most convenient shutter is that known as a blind shutter M placed behind the
mirror F and immediately before the sensitive plate which blind shutter M would
proferably he constructed in the ordinary manner with two apertures one being a large
one for timed or prolonged exposures the other being a narrow one for instantaneous
exposures.
Any ordinary and suitable means and appliances may be used in this camera to
move and operate the mirror and the shutter in their due required and necessary
sequence.
For example an india rubber pocket or other pneumatic bellows may be fitted in
the casing below the mirror which can be operated from outside the casing by a
collapsible ball and is connected with the mirror by a link or otherwise in such manner
that when and as the same is distended the mirror is folded up against and parallel
or thereabouts with the ground glass and then the framing of the mirror may come
in contact with a spring catch or other appliance that will operate the shutter while
the release of the ball will allow the mirror to regain its normal position.
Again I may pivot a lover in the casing one end whereof can be depressed by a
push pin outside the casing which depression causes the other arm of the lever to
raise the mirror as aforesaid until the extreme end of this arm of the lever also comes
in contact with a spring catch or other appliance that will operate the shatter while
the release of the push pin will allow the inirror to regain its normal position.
Again I shew in the drawing a very convenient arrangement of these parts of my
camera and a very suitable apparatus for operating the same. The blind shutter M
is mounted on the two horizontal rollers N and N and gearing into or connected with
the upper roller N is a wheel O mounted on the side of the casing A which can be
revolved from the outside thereof by a suitable key and on the face of this wheel O is
a cam P shaped as shewn in Figure 1 whoreinto or whereon à stud Q on the frame of
the mirror can engage and a spring pawl R also mounted on the side of the
casing A can be operated from the outside thereof by and through the push pin S
which pawl R is normally kept by its spring in such position as to be in the path of
a stud or stop T on the side of the wheel O." When the camera is arranged and the
blind shutter is constructed for both timed or prolonged and instantaneous exposures
two stops T and T are fitted on the wheel O in such positions in relation to the shutter
that one stop is for the timed or prolonged exposure while the other is for the insuin-
taneous exposure. The lower roller N contains or is fitted with the spring which
actuates the shutter M which spring may be of any ordinary and suitable coiled or
other description and gearing into or connected with the spindle or centre of this
spring is a wheel U mounted on the side of the casing A which can be revolved from
the outside thereof by a suitable key and is fitted as is shewn in Figure 3 which is an
elevation thereof partly in section. A ratchet wheel V mounted in a bracket in such
wise that it cannot revolve engages a complementary ratchet on the wheel U being
pressed thereinto by the spring W. The keyhole X through which the wheel U can
be turned to wind up the spring of the roller N and thus increase its tension and
consequently the speed of the shutter M which action is allowed and which effect is
maintained by the ratchet wheel V passes right through the wheel U so that the key
being passed through this keyhole X can be pressed against the ratchet wheel V and
forcing the same out against its spring W will disengage it from the wheel U
which therefore can be turned in the other direction to decrease the tension of the
spring of the roller N and consequently to lessen the speed of the shutter M when
desired.
The method of using this camera and the action of the several parts thereof are as
follows. The desired tension is put on the spring of the lower roller N and the
shutter M is rolled up on the upper roller N against the spring until the proper
aperture therein is on the upper roller N' in readiness to pass down in front of the

page_text: sensitive plate and this upper roller N¹ is then held in this position by the pawl R.
The image is duly focussed on the ground glass and the known correction if any is
duly applied to such focussing the dark slide is placed in position and the sensitive
plate therein is uncovered. Then at the proper moment the pawl R is disengaged by
the push pin S from the stop T and the lower roller N is allowed to revolve causing
the blind shutter M to pass down in front of the sensitive plate and as the wheel Ŏ
revolves the cam P thereon raises the mirror F through the stud Q until the mirror F
no longer intercepts the light and is in the position shewn by dotted lines in Figure 1
or thereabouts at which time the aperture in the shutter M has left the upper roller N'
and is in front of the sensitive plate and the desired exposure is given thereto. If
this exposure be the timed or prolonged exposure and therefore the large aperture in
the shutter DI be in front of the sensitive plate the pawl P then engages the other
stop T and thus all parts are retained in their respective positions as long as may be
desired when the pawl R is again disengaged by the push pin S from the stop T and
the lower roller N is again allowed to revolve causing the blind shutter M again to
pass down in front of the sensitive plate removing the aperture therefrom and as the
wheel revolves the cam P thereon allows the mirror F to regain its normal position.
If on the other hand this exposure be the instantaneous exposure and therefore the
narrow aperture in the shutter M be in front of the sensitive plate there is no stop in
the action and no retention of the parts in their respective positions but the action
herein before described proceeds without a stop to its proper completion. The shutter
then can again be properly rolled up on the upper roller and another sensitive plate be
uncovered and the aforesaid procedure can be repeated and so on.
It is sufficiently obvious that a very similar procedure would be observed and
followed when an india rubber pocket or other pneumatic bellows or a lever as herein-
before described are used to operate the moving parts of this camera and no further
description of the use of the same when so fitted is or can be needed.
Again when other shutters are used in this caméra they can be fitted with their
ordinary actuating appliances which appliances in any usual or convenient manner
would be so connected with the mirror or with its operating appliance that the raising
of the mirror shall operate the shutter.
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 1
claim is
In a photographic camera the arrangement and combination of parts and appliances
substantially as hereinbefore described and shewn in the accompanying drawing.
..
JCT.... 1900
HART & Co.