Certain Improvements in Photographic Shutters.
Year: 1896

page_text: Date of Application, 4th Apr., 1896
PROVISIONAL SPECIFICATION.
Certain Improvements in Photographic Shutters.
I, EDWIN UNDERWOOD, trading as E. & T. Underwood, of 130 and
132, Granville Street, Birmingham, Warwickshire, Photographic Apparatus
Manufacturer, do hereby declare the nature of this invention to be as follows:-
This invention consists of the hereindescribed improvements in combined time
and instantaneous photographic shutters, that is to say, those photographic shutters
which can be used either to give an instantaneous exposure, or a time exposure for
a picture with a foreground where the shutter is required to give a gradually
diminishing exposure and closes by rising so as to give the least exposure to
the sky.
In carrying out this invention I provide a roller shutter or blind which has the
exposure aperture at about the middle of its length and is wound on to a roller at
the top of the shutter box or casing and on to another roller at the bottom of the
same. The top roller is a spring roller and tends to roll the blind or shutter
thereon and the bottom roller is provided with two cords one of which is shorter
than the other and both of which will be wound on the roller as the shutter is
wound off the same on to the top roller. By pulling the longer cord an exposure
is obtained as the shutter is wound off the top roller on to the bottom roller the
exposure being obtained as the opening passes the lens. By pulling the shorter
cord a time exposure is obtained as when this cord is pulled as far as it will go a
part of the shutter is wound on the bottom roller and the opening is brought
opposite the lens thus giving the time exposure and then when this cord is released
the shutter is re-wound on the upper roller rising from the bottom and giving the
least exposure to the sky.
The top roller is provided with a disc or cam in which is a notch and to engage
with this notch there is a spring lever which, when the shutter has been wound on
the bottom roller by pulling the longer cord, springs into the notch and prevents
the recoil of the top roller. To release the shutter to give an instantaneous
exposure the said spring lever has to be forced sideways out of the notch so as to
release the spring roller and allow of the shutter winding thereon. This releasing
of the shutter can be done by means of a pneumatic pusher. In combination with
this spring lever I employ a spring prop or catch which acts upon the spring lever
and is so arranged that when the prop or catch is turned in one direction it will
force the spring lever sideways and prevent its engaging with the cam so that the
shutter can then be used for the time exposure; and by turning the prop or catch
in the opposite direction it will release the catch lever and allow of the same
engaging with the cam of the spring roller to hold the same set for the instantaneous
exposure as above described.
Instead of using the short cord for winding the shutter off the spring roller on
to the other roller, I may use the following arrangement of mechanism which forms
one of the important features of this invention and also serves the purpose of
holding the shutter open during the time exposure and of releasing and allowing
the same to close. Upon one end of the roller spindle I provide a small pinion and
gearing with this pinion there is a toothed sector turning on a suitable pin and
fixed to another toothed pinion which turns with the sector on the same pin.

page_text: Gearing with the second pinion there is a second toothed sector made in the form
of a lever to be acted on by a pneumatic pusher in one direction and by a spring
on the opposite direction against the pusher. When the usual hollow ball part of
the pneumatic pusher is squeezed in the usual way the pneumatic pusher will act
upon and turn the second toothed sector which in its turn will turu the second
pinion and also the first sector which latter will turn the roller by gearing with
the said pinion upon it and thus unwind the shutter or blind off the spring roller
and on to the other roller far enough to bring the opening opposite the lens and
give the time exposure. When it is desired to terminate the exposure it is only
necessary to release the pneumatic ball when the pneumatic pusher will allow the
spring to act upon the second toothed sector and the gearing and spring roller so
that the latter will wind back the shutter. When in its normal position the first
named toothed sector has turned far enough away out of gear with the pinion on
the roller so as to permit of the roller being free to be turned by the spring roller
when the shutter is being used for an instantaneous exposure. In combination
with the said toothed sectors or one of them there may be a catch piece which can
be turned so as to come in contact with the same and prevent them moving when
the shutter is being used for an instantaneous exposure.
The gearing above described for the time exposure is by preference arranged to
be worked by a pneumatic pusher on one side of the shutter box and the catch
lever release for the instantaneous exposure is worked by a pneumatic pusher on
the other side of the shutter box. Both of these pneumatic pushers may be
arranged to be worked from the same air ball by suitable air tubes and taps to shut
off communication from that pusher which is to be inoperative.
Dated this 2nd day of April 1896.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.
Certain Improvements in Photographic Shutters.
I, EDWIN UNDERWOOD, trading as E. & T. Underwood, of 130 and
132, Granville Street, Birmingham, Warwickshire, Photographic Apparatus
Manufacturer, 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 consists of the hereindescribed improvements in combined time
and instantaneous photographic shutters, that is to say, those photographic shutters
which can be used either to give an instantaneous exposure, or a time exposure for
a picture with a foreground where the shutter is required to give a gradually
diminishing exposure and closes by rising so as to give the least exposure to
the sky.
I will describe my invention by referring to the accompanying drawings on
which
Fig. 1 represents a photographic shutter and operating mechanism arranged
according to one arrangement of my invention set for use for giving a time
exposure; Fig. 2 is a side elevation of the same shutter set for giving an
instantaneous exposure; Fig. 3 shews the roller blind part of the said shutter
separately on a smaller scale;
Fig. 4 is a front view of a photographic shutter constructed according to another
arrangement of my invention; Fig. 5 is a view of one side of the same and Fig. 6
is a view of the other side of the same.

page_text: The same letters of reference indicate the same parts in all the figures.
I will first describe the arrangement of my invention shewn by Figs. 1, 2 and 3.
In carrying out this invention I provide an ordinary roller shutter or blind A
which has the exposure aperture B at about the middle of its length (see Fig. 3)
and is wound on to a roller Cat the top of the shutter box or casing D and on to
another roller E at the bottom of the same. The top roller C is a spring roller
and tends to roll the blind or shutter A thereon and the bottom roller E is
provided with two cords F and G of which the cord F is shorter than the other
cord G and both of which will be wound on the roller E as the shutter A is wound
off the same on to the top roller C. By pulling the longer cord G an exposure is
obtained as the shutter is wound off the top roller C on to the bottom roller E the
exposure being obtained as the opening B passes the lens. By pulling the shorter
cord F a time exposure is obtained as when the cord is pulled" as far as it will go
(as shewn in Fig. 1) the lower part of the shutter A is wound on the bottom
roller E and the opening B is brought opposite the lens thus giving the time
exposure and then when this cord F is released the shutter A is re-wound
on the upper roller C rising from the bottom and giving the least exposure to
the sky.
The top roller C is provided with a disc or cam H in which is a notch h¹ and to
engage with this notch there is a spring lever I jointed at to the side of the
shutter box, which lever (when the shutter A has been wound on the bottom
roller E by pulling the longer cord G) springs into the notch and prevents the recoil
of the top roller C. To release the shutter A to give an instantaneous exposure
the spring lever I has to be forced sideways out of the notch ' so as to release the
spring roller C and allow of the shutter A winding thereon. This releasing of
the shutter can be done by means of an ordinary pneumatic pusher part of which
is shewn in Figs. 1 and 2 and marked J. In combination with the spring lever I
there is a prop or catch K turning on a screw which is so arranged that when
the prop or catch is turned in one direction as shewn in Fig. 1 it will force the
spring lever I sideways and prevent its engaging with the cam H so that the
shutter can then be used for the time exposure by pulling the shorter cord Fas
aforesaid; and by turning the prop or catch K in the opposite direction (see
Fig. 2) it will release the catch lever I and allow of the same engaging with the
cam H of the spring roller C to hold the same set for the instantaneous exposure
as above described.
It will be evident that the shutter above described may either be used with the
spring roller C at the top as shewn in Fig. 1, as is necessary when the shutter is
used at the back of the lens, or the shutter box may be reversed with the spring
roller C at the bottom as is required when the shutter is used at the front of the
lens.
Instead of using the short cord F for winding the shutter A off the spring
roller C on to the other roller E, I may use the following arrangement of
mechanism illustrated by Figs. 4 and 5 which forms one of the important features
of this invention and also serves the purpose of holding the shutter A open during
the time exposure and of releasing and allowing the same to close at the termination
of the exposure.
In Figs. 4, 5 and 6 I have shewn the spring roller C at the
bottom of the shutter box. Upon one end of the spindle e¹ of the roller E
I provide a small pinion L and gearing with the pinion L there is a toothed sector
or partial wheel M turning on a suitable pin m¹ and fixed to another toothed
pinion N which turns with the sector or partial wheel M on the same pin m¹.
Gearing with the second pinion N there is a second toothed sector O made in the
form of a lever turning on a pin o' at one end and arranged to be acted on by a
pneumatic pusher in the direction indicated by the arrow in Fig. 5 and by the
tension spring Q in the opposite direction against the pusher P. When the usual
hollow ball part T of the pneumatic pusher is squeezed in the usual way the
pneumatic pusher P will expand and act upon and turn the second toothed sector

page_text: which in its turn will turn the second pinion N and also the first sector or partial
wheel M which latter will turn the roller E by gearing with the pinion L upon its
spindle e and thus unwind the shutter or blind off the spring roller C and on to
the other roller E far enough to bring the opening B opposite the lens and give the
time exposure. When it is desired to terminate the exposure it is only necessary
to release the pneumatic ball when the pneumatic pusher P will contract and allow
the spring to act upon the toothed sector () and the gearing N M L and spring
roller C so that the latter will wind back the shutter A. When in its normal
position shewn in Fig. 5 the first named toothed sector or partial wheel M has
turned to such a position that the toothless space m² is next the pinion L and the
teeth of the wheel M are out of gear with the piuion L on the roller E so as to
permit of the roller E being free to be turned by the spring roller C when the shutter
is being used for an instantaneous exposure. In combination with the said toothed
sector there is a catch piece R which can be turned so that its notch will
engage with the pin o³ on the sector O and thus lock the same and prevent the
sectors moving when the shutter A is being used for an instantaneous exposure.
The gearing above described and shewn in Figs. 4 and 5 for the time exposure
is by preference arranged to be worked as shewn by the pneumatic pusher Pon
one side of the shutter box D, and the catch lever I for the release for the
instantaneous exposure is worked by the pneumatic pusher J on the other side of
the shutter box. Both of these pneumatic pushers P and J may if desired be
arranged to be worked from the same air ball T by their air tubes p¹ and j¹ being
joined to the pipe t' connected to the air ball T.
I wish it to be understood that I make no exclusive claim to the roller blind A
and its rollers and E apart from the particular meaus which I have described
for operating the roller to enable an instantaneous or a time exposure to be given
at the will of the operator.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is
1. In a photographic shutter arranged for giving either an instantaneous
exposure or a time exposure, the combination with the shutter box of the roller
blind A made with a central aperture B, a spring roller C and roller E connected
respectively to the ends of said blind, the cords F and G fixed to the roller E one
of the said cords being only long enough to roll so much of the blind on the roller
as will bring the aperture in the blind opposite the lens and the other cord being
long enough to roll the said aperture past the lens on to the said roller, means for
retaining the spring roller set for an instantaneous exposure and the prop adapted
to prevent the catch lever from holding the spring roller when the shutter is being
used for a time exposure, all substantially as hereinbefore described and illustrated
by Figs. 1, 2 and 3 of the accompanying drawings.
2. In a photographic shutter arranged for giving either an instantaneous or a
time exposure, the combination with the shutter box of the roller blind made with
an aperture, a spring roller C and roller E connected respectively to the ends of
said blind, and the mechanism arranged and operating substantially as herein before
described with reference to Figs. 5 and 6 of the accompanying drawings for
winding the blind off the spring roller on to the other roller for giving the time
exposure and for causing the said blind to rewind on to the said spring roller at
the termination of the exposure and means at the other side of the said shutter box
for retaining the spring roller set for an instantaneous exposure and for releasing
the same by the pneumatic pusher, all substantially as herein before set forth.
3. In a time exposure photographic shutter made with a roller blind having an
exposure aperture and a spring roller and another roller connected respectively to
the ends of said blind, the employment of the mechanism substantially as herein-
before described and illustrated by Figs. 4 and 5 for causing the pneumatic pusher

page_text: to wind the blind off the spring roller and on to the other roller to give the time
exposure and to allow of the said blind rolling back on to the spring roller at the
termination of the exposure as herein before set forth.
Dated this 2nd day of January 1897.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.