Improvements in Photographic Shutters.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Photographic Shutters.
I, ARTHUR BRYCE MEES, of Comberton Villa, Stourbridge, in the County of
Worcester, Mechanical Engineer, do hereby declare the nature of this invention
to be as follows:-
My invention relates to improvements in photographic shutters to be used more
particularly in connection with hand cameras and has for its object the con-
struction of a shutter in which the parts for operating are arranged in a more
compact form than in shutters as hitherto constructed and consists of two plates
jointed together with a space between for shutter to revolve, on the outside of
one plate is fixed a thimble having one end open to correspond to opening in
plate the other end of thimble having a smaller opening which leaves an internal
flange, a cap having corrugations on outside which engage with a pawl fixed to
thimble and allows cap to be moved in one direction only is fixed to a tube which
passes through opening in thimble and a hole in second or back plate, between
the two plates is a shutter having an aperture which will admit light through
apertures in the two plates this shutter is fixed to a sleeve which turns on central
tube this sleeve has a projection or stop which engages with projections or stops
fixed inside thimble, inside the tube is a key capable of sliding in tube one end
projecting beyond cap the inside end having a projection which passes through
a slot in tube and engages with the sleeve, as spring having one end attached to
tube the other end attached to shutter is so arranged that after being wound up
by means of turning cap a required distance the larger coils engage with a stop
and cause the smaller coils to be wound and in this manner variable tensions are
obtained for the purpose of obtaining various speeds, in the front of the cap is
a hole which exposes one of the numbers marked on the flange of thimble these
numbers indicate the speeds shutter will revolve at when cap is turned to expose
any particular number. The action of setting the shutter is as follows, the cap
is turned to expose the desired speed number, by the action of turning the cap
the shutter is moved by means of the spring until the stop on sleeve engages with
stop on thimble thus preventing shutter moving further and allowing a tension
to be put on spring, upon pressing key the sleeve stop and shutter are moved
until the stops disengage and spring pulls round the shutter and causes the
aperture in shutter to pass the apertures in plates, the action of setting may then
be repeated by turning cap.
For a *
time" exposure the cap is turned to a
position marked on the thimble when in this position the key engages with a
stop fixed to thimble and by limiting the sliding motion of key allows shutter
to miss one stop and engage with a second one, upon releasing pressure from
key the shutter is moved forward by means of spring and shutter disengages
with the second stop and moves until arrested by a third stop which is in a
position that brings the aperture of shutter in same position as apertures in
plates, upon pressing in the key the shutter is released from third stop and covers
apertures in plates, by these means when the cap is turned to a speed

page_text: number, one pressing of key gives the exposure, and when cap is turned to
"time" one pressing of key opens shutter and a second pressing closes same.
Dated this 18th day of January 1898.
I, ARTHUR BRYCE MEES, of Comberton Villa, Stourbridge, in the County of
Worcester, Mechanical Engineer, 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 relates to improvements in photographic shutters to be used more
particularly in connection with hand cameras and has for its object the con-
struction of a shutter in which the parts for operating are arranged in a more
compact form than in shutters as hitherto constructed.
In order that my invention may be clearly rendered reference may be had to
the accompanying sheet of drawings, in which
Fig. 1 is a front elevation.
Fig. 2 is a side elevation.
Fig. 3 is a front elevation shewing section through w x.
Fig. 4 is a sectional side elevation.
Fig. 5 is an elevation of back of shutter shewing spring.
Fig. 6 is a sectional side view of shutter shewing sleeve cap and tube.
Fig. 7 is a front elevation of projections.
Fig. 8 is a sectional side view of projections.
Fig. 9 is an elevation of thimble shewing pawl.
Fig. 10 is a front view of thimble shewing pawl and figures.
Figure 11 is a front elevation shewing position of shutter when released, and
section through wa.
The same letters of reference indicate the same parts in the said Figures 1
to 11.
a and a¹ are the two plates flanged to fit together. b is a thimble having one
end open to correspond to opening in plate a the other end of thimble having
a smaller opening which leaves an internal flange d.
e is a cap having corrugations 2 on outside which internally engage with a
spring pawl f fixed to thimble b.
The cap e has an internal rim in the centre which passes through the hole d
in thimble and is turned over as e³ to prevent cap from coming off thimble
One end of tube g is fixed to cap at e³ the other end passes through a hole h
in centre of plate a and turns in the cap which is fixed to plate a.
The shutter i having an aperture y is fixed to a sleeve which moves on and
around the tube 9. The stop m on sleeve / engages with projections n n' and n² on
ring which is fixed inside thimble. Inside the tube 9 is a key o having a
projection p which passes through a slot in tube g and which can be moved in-
wards so that the projection p will move the sleeve and shutter i along the
tube so that the stop m will miss the projections n n¹ and n³.
The spring 63 is so constructed that the small coils 65 will go inside the tube g
and extend from inside plate a to the key o and keep the key in the position
shewn in Fig. 4. This spring passes through the slot in tube
the tube through the eyes the end being fixed to the eye b³,
and coils outside

page_text: The spring 62 is arranged with a stop 6 which will come in contact with the
eyes when spring is wound up.
The plates a and a have an aperture h² opposite each other.
The hole c¹ in cap e exposes the numbers d' when the cap is turned on thimble b
and the pawlf keeps the cap in the position to which it is turned. The method
of working the shutter is as follows:-
Say for instance it is desired to give a time exposure and that the shutter has
been released from a time exposure the cap e being in the position shewn on
Fig. 1 and the shutter i in the position shewn on Fig. 11.
The cap e would be turned to the right until the figure T which indicates a
time exposure is visable, the spring being taken round by the slot in tube g
pulls round the shutter i for half a revolution until the stop m comes in contact
with the projection n and the shutter i being kept in the position shewn in
Fig. 3 the spring will be wound up during the remaining half revolution which
the cap will be turned in order to expose the figure T.
Upon pressing the key o the sleeve will be moved until the projection p
comes in contact with the projection 2, this motion will be sufficient to move
the stop m and clear the projection n so that the spring pulls round the shutter i
until the stop m is arrested by the projection n which is set back as shewn in
Fig. 8, upon releasing the key o the spring 65 returns it and the
spring acting between the plate a and the shutter i returns the
shutter SO that the stop m clears the projection n¹ and allows the
spring to pull round shutter until arrested by projection 2 which is in a position
that brings the aperture between the apertures 2 in which position the shutter
will remain allowing the light to pass through the apertures h² until the key o
is again pressed which will cause the stop m to clear the projection 72 and the
spring will pull round the shutter i into its normal position shewn on Fig. 11.
In order to give a speed-exposure the cap is turned to one of the Figures 12
or 3, upon pressing in the key o the projection will move inwards clearing the
projection and will move the sleeve a sufficient distance for the stop m to clear
the projections n n¹ and n² so that the shutter will be pulled by means of the
spring to its normal position giving an exposure whilst the aperture of shutter
passes the apertures of plates a and a². The spring is so arranged that after it
is wound up half a revolution the larger coils being the weakest the stop 4 will
travel half a revolution so that when the cap e is turned to T the stop 4 will
come in contact with the eye s so that upon moving the cap beyond T the smaller
and therefore stronger coils of spring will be wound so that the tension of spring
increases in a greater ratio after the first half revolution and the Figures 1 2
and 3 represent a greater increase of speed in the working of the shutter than
would be effected by the use of a plain spring.
I do not confine myself to the use of any particular number of figures to repre-
sent the various specxls, or to the number of stops on spring and eyes on shutter
to effect various tensions.
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:
First. In a shutter for giving exposures for photographic purposes having a
combination of parts whereby a cap can be turned to an indicated position for
a time exposure when a key in the centre of said cap upon being pressed and
released will cause the shutter to open and remain open until the key is again
pressed which will close shutter and in which upon the cap being turned to an
indicated position for a speed exposure one pressing of the central key will allow
the shutter to open and close, the said shutter being arranged and operated sub-
stantially as hereinbefore described.
Secondly. In a revolving shutter worked in one direction only in which after

page_text: winding a spring a required distance the larger coils are stopped off allowing the
smaller coils to be wound substantially as herein before described.
Thirdly. In a shutter in which a central key having a projection sliding in
a slot in a central tube moves a sleeve and shutter along the said tube for the
purpose of engaging or disengaging with fixed projections in order to give time
or speed exposures, arranged and operated substantially as hereinbefore described.
Dated this 17th day of October 1898.
ARTHUR BRYCE MEES.