Improvements in Photographic Shutters.
Year: 1892

page_text: Date of Application, 23rd Mar., 1892
Complete Specification Left, 23rd Dec., 1892-Accepted, 28th Jan., 1893
PROVISIONAL SPECIFICATION.
Improvements in Photographic Shutters.
We, ARTHUR SAMUEL NEWMAN and JULIO GUARDIA, trading as Newman &
Guardia of 71, Farringdon Road, London in the County of Middlesex, Photo-
graphic Apparatus Manufacturers, do hereby declare the nature of this invention
to be as follows :-
This invention relates to improvements in photographic shutters of the character
known as "blind" shutters and has for its object to improve the construction and
operation of such shutters.
Our present invention is as follows:-
The frame or support may be made of any suitable material but we find it very
advantageous to use aluminium as such material gives great strength with lightness
and durability and is not liable to warp or change its shape as is the case with
wood.
Within a case at each end of this frame we mount a roller (which may also be
made of aluminium) with which is combined either a spiral helical or other suitable
spring one end of which is attached to the roller and the other to the frame.
The other roller has a pinion fixed to the axis or axle thereof and this pinion in
<< setting "the shutter is actuated by a rack of either straight or other form.
One end of this rack is connected to a pneumatic piston and the movement of
this rack when the shutter is released is controlled by said pneumatic piston
working in a cylinder that is the movement of the rack is pneumatically regulated
either in accordance with the said Arthur Samuel Newman's Patent No. 7156 of
1886 or otherwise pneumatically regulated.
Any usual or well-known pneumatic release is used to operate the catch which
holds the rack in the position "set" ready for giving an exposure or to hold the
shutter "open" during exposure or focussing.
$6
The blind" having an aperture therein is wound off one roller on to the other-
to "set" the shutter ready for exposure-by moving the said rack by means of a
knob or handle or other attachment to the said rack this movement causing the
winding of the aforesaid roller spring. On releasing the rack the "blind" is wound
back again on to the first roller by the re-action of the aforesaid spring and the
rack is returned--by the said revolving pinion on the said roller axis-to its normal
position. The speed of its return being regulated by the movement of the piston in the
pneumatic cylinder this regulation being effected either by varying the distance
that the piston is caused to travel or by varying the size of the aperture or apertures
through which air is expelled or drawn in as the case may be.
According to our present invention we also provide an extra space at the end of
the pneumatic cylinder so as to form an air cushion or buffer to prevent or reduce
jar or vibration when the exposure is completed.
A dial or other index is or may be arranged and combined with the pneumatic
cylinder so as to thereby indicate the speed at which it is desired the shutter
should work.
This shutter may be arranged and mounted to work on the front of the lens or
at any other convenient point for instance it may be arranged within the camera
case.
Dated this 23rd day of March 1892.
TONGUE & BIRKBECK,
34, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Photographic Shutters.
We, ARTHUR SAMUEL NEWMAN and JULIO GUARDIA, trading as Newman &
Guardia of 71 Farringdon Road, London, in the County of Middlesex, Photo-
graphic Apparatus Manufacturers, 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 improvements in photographic shutters of the character
known as "blind" shutters and has for its object to improve the construction and
operation of such shutters-especially the regulation.
Our present invention is as follows:-
The frame or case may be made of any suitable material but we find it very
advantageous to use aluminium as such material gives great strength with lightness
and durability and is not liable to warp or change its shape as is the case with
wood.
Within this case or frame and at each end thereof we mount a roller
advantageously of large diameter (which may also be made of aluminium) with
which is combined either a spiral helical or other suitable spring one end of which
is attached to the roller and the other to the frame.
$6
The other roller has a pinion fixed to the axis or axle thereof and this pinion in
setting" the shutter is actuated by a rack of either straight or other suitable
form.
One end of this rack is connected to a pneumatic piston and the movement of
this rack when the shutter is released is controlled by said pneumatic piston working
in a cylinder that is the movement of the rack is pneumatically regulated.
Any usual or well-known pneumatic release is used to operate the catch which
holds the rack in the position "set" ready for giving an exposure or to hold the
shutter "open" during exposure or focussing.
"
66
The "blind" having an aperture therein is wound off one roller on to the other-
to " set the shutter ready for exposure-by moving the said rack by means of a
knob or handle or other attachment to the said rack this movement causing the
winding of the aforesaid roller spring. On releasing the rack the blind" is
wound back again on to the first roller by the re-action of the aforesaid spring and
the rack is returned (by the said revolving pinion on the said roller axis) to its
normal position. The speed of its return being regulated by the movement of the
piston in the pneumatic cylinder this regulation being effected either by varying
the distance that the piston is caused to travel or by varying the size of the
aperture or apertures through which air is expelled or drawn in as the case may be.
According to our present invention we also provide an air cushion or buffer at
the end of the pneumatic cylinder to prevent or reduce jar or vibration when the
exposure is completed and thus reduce wear and tear of the working parts and
making the whole apparatus work smoothly.
A dial or other index is or may be arranged and combined with the pueumatic
cylinder so as to thereby indicate the speed at which it is desired the shutter
should work.
This shutter may be arranged and mounted to work on the front of the lens.or
at any other convenient point for instance it may be arranged within the camera
case.
And in order that our present invention may be fully understood and readily
carried into practice we will proceed to describe same with reference to the sheet
of drawings hereunto annexed.

page_text: DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a front elevation of a roller blind shutter having our improvements
applied thereto.
Fig 2 is a side elevation looking in the direction of the arrow = Fig. 1.
·
Fig. 3 is a local enlarged view of the upper part of Fig. 2--parts being broken
out in order to show details.
a is the body or frame of the shutter which we find it advantageous to make of
aluminium for the reasons hereinbefore stated.
This case a is made in the form of a hollow box as is well known and under-
stood in blind shutters.
b is the lower roller combined with a spring or springs (not shown) which
normally keeps the blind e wound upon it.
is the upper roller upon the axle of which is fixed the pinion or toothed
wheel d.
e is the blind which is successively wound backwards and forwards on and off the
large rollers b and c as is well understood in blind shutters.
is the rack which in the case illustrated is a straight rod the lower end of
which is fixed to a piston y working in the pneumatic cylinder h-the teeth on this
rack gear with the teeth of pinion d.
i is the free end of the rod f by means of which said rod f is pulled out to wind
the blind e on to roller c off the roller b.
jis lug or projection through a slot in which the rack f passes so as to act as
guide for said rack f.
k is a pin or stud on f to hold the shutter open for long exposures or focussing
and is a second pin or stud on to hold the shutter set ready for giving exposures
i.e. when the rack is drawn out to the full extent as shown in Fig. 2 the stud / is
held on the releasing spring catch m.
as is
The releasing catch m formed as a bell crank turns on the pivot n and is actuated
by the other end thereof m¹ being raised by the ordinary pneumatic releasing
device consisting of piston o and cylinder p operated by squeezing the ball
well understood. Thus on raising the end m¹ the catch m is thrown clear of and
allows the wound spring on to quickly wind off the blind-the air in the
cylinder serving as a brake to regulate the speed when such blind is wound off c.
r is a stop to prevent m' travelling too far. At the lower end of the cylinder h
is an apertures which is controlled by the revolving cover t this regulating cover t
is turned on the pivot or centre by means of a handle or knob v-a pointer w
on u serving to indicate on a dial the duration of the exposure which will be
given according as the pointer w is moved upon said dial.
Below the orifice or controller apertures the cylinder is prolonged so as to
form additional space at the end A of the regulating cylinder / so as to form an
air cushion or air buffer at the bottom A of said cylinder to prevent or reduce jar
or vibration when the exposure is given and thereby prevent or reduce wear on the
working parts.
The operation is as follows:-
To set the shutter it is only necessary to grasp the knob i on the rack f (Fig. 1)
and draw same out until the stud on said rack f is caught and retained on the
spring catch m as shown in Fig. 2 and the shutter is now set ready for giving an
exposure.
By pressing the ball the pneumatic releasing device throws m free of 7 and the
blind e is then wound as rapidly off 6 and on to c as the pneumatic regulation will
permit that is to say the blind being wound off c rotates the pinion d and thereby
forces the rack f with piston g thereon down the cylinder and according to the
tightness of closure over aperture s so will the speed of the travel of the blind e be
regulated while after the piston 9 has passed the orifices (the exposure having
taken place and the light already completely shut off) the air in the lower end Å

page_text: of the cylinder h having no means of ready escape will thus act as a buffer or air
cushion to prevent or reduce jar or vibration at the end of the down strok
off and g-this means of preventing or reducing jar or vibration and thus reducing
wear and tear of the working parts being an important point in our present
invention.
It will be obvious that in place of the rack and pinion illustrated-we may
substitute any well-known means of converting rotary motion into reciprocating
motion and interpose such equivalents for the rack and pinion between the axle of
one of the blind rollers and the pneumatic regulating cylinder and piston.
A further obvious modification would be simply arranging the pneumatic
regulating cylinder and piston vice versa-that is the cylinder connected to and
moving with the rack and the piston fixed for such cylinder to work on.
We would remark that we are well aware that blind shutters are not new and
that the pneumatic releasing device is not new nor pneumatic regulation in itself
(the latter having been invented and patented by the said Arthur Samuel Newman
in 1886, No. 7156) and we therefore make no claim herein to any of these features
separately.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The combination in a roller blind shutter for photographic purposes- of a
pinion fixed on the axle of one of the rollers (on which latter the said blind is
wound on and off') a rack or its equivalent gearing with said pinion and a piston
travelling in a pneumatic cylinder said piston being fixed or connected to said rack
so as thus to control and regulate the speed of rotation of said pinion and thereby
regulate the duration of the exposure given.
2. In a pneumatic regulating device for photographic shutters-the combination
and arrangement of the regulating orifice in the cylinder in such a position as to
leave a space at the inner end only of said cylinder from which space the air cannot
freely escape and therefore acts as an air cushion or buffer at the end of the stroke
so as to thereby reduce jar and wear on the working parts substantially in the
manner and for the purposes hereinbefore set forth.
3. The combination with a photographic roller blind shutter of a pinion fixed on
the axle of one of the rollers, a rack or its equivalent gearing with said pinion, a
piston fixed or connected to said rack, a pneumatic cylinder in which said piston
works, means to vary the resistance offered by the air in said cylinder to the said
piston and the said cylinder having the regulating orifice therein in such a position
as to leave a chamber or space at the closed end of said cylinder from which the
air cannot freely escape and therefore such air acts as a buffer or cushion
substantially in the manner and for the purposes hereiubefore described and
illustrated in the drawings hereunto annexed.
Dated this 23rd day of December 1892.
TONGUE & BIRKBECK,
34, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicants.