Improvements in connection with Diaphragms or Stops for use with the Lenses of Photographic Cameras.
Year: 1889

page_text: Date of Application, 24th Jan., 1889
Complete Specification Left, 21st Nov., 1859--Accepted, 11th Jan., 1890
PROVISIONAL SPECIFICATION.
Improvements in connection with Diaphragms or Stops for use with
the Lenses of Photographic Cameras.
We JOHN STUART of The Hollies Clapham Common in the County of Surrey
Optician and GEORGE HARROP of 30 Russell Road Holloway in the County of
Middlesex Engineer do hereby declare the nature of this Invention to be as
follows:-
This Invention relates to the stops or diaphragms known as the “Iris" and has for
its objects to enable the diaphragm or stop and its holding and operating rings to be
contained entirely within a lens tube or mounting of the usual size and also to provide
means whereby the operator can (without necessitating reference to a scale) with
great facility and certainty adjust the diaphragm or stop definitely to any set size of
aperture without danger of its accidentally becoming altered. To effect this the ring
to which one end of the component members leaves or strips are centered is made of
a size to fit in the lens tube or mounting and the ring to which the other ends of the
said members leaves or strips are centered is provided with slots extending from the
inner circumference to near the outer circumference where the said ring is strengthened
by a supplementary ring or annulus preferably at right angles thereto. A stem attached
to this slotted ring or the supplementary ring projects through a slot in the tube or
mounting for enabling the operator to adjust the aperture.
In a suitable part (for instance in a ring secured within the casing which contains
the diaphragm) notches or recesses are made with which engages a spring or catch
secured to any suitable part (for instance to the ring which is slotted as aforesaid).
The free end of the spring catch that enters the recesses or divisions in the ring allows
the ring to be rotated but as it comes opposite the notches or recesses the operator is
aware that the diaphragm or stop then presents a certain known and definite aperture
in accordance with the recess or notch with which the catch is engaged.
The tube or mounting of the lens may be provided with divisions marked so that
the position of the stem corresponding with any given aperture.may be ascertained by
reference to the scale or projections recesses or the like may be used instead of the
scale or in addition thereto so that by running the finger over them they may be
readily counted and the aperture thus ascertained in a dark place.
Dated this 24th day of Jo 1000
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in connection with Diaphragms or Stops for use with
the Lenses of Photographic Cameras.
We JOHN STUART of The Hollies Clapham Common in the County of Surrey
Optician and GEORGE HARROP of 30 Russell Road Holloway in the County of
Middlesex 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 :-
This Invention relates to the stops or diaphragms known as the "Iris" and has for
its objects to enable the diaphragm or stop and its holding and operating rings to be
contained entirely within a lens tube or mounting of the usual size that is a lens tube
or mounting whose internal diameter does not exceed that of the full opening or
aperture of the lens or diaphragm more than in the proportion of 3 to 2 and also to

page_text: provide means whereby the operator can (without necessitating reference to a scale)
with great facility and certainty adjust the diaphragm or stop definitely to any set size
of aperture without danger of its accidentally becoming altered. To effect this the
ring to which one end of the component members leaves or strips of the diaphragm
or stop are centered is made of a size to fit in the lens tube or mounting of the usual
size and the ring to which the other ends of the said members leaves or strips are
centered is provided with slots extending radially from or near the inner circumference
to or near to the outer circumference the said ring being strengthened by a supple-
mentary ring or annulus preferably at right angles thereto. A stem attached to this
slotted ring or the supplementary ring projects through a slot in the tube or mounting
for enabling the operator to adjust the aperture.
In a suitable part (for instance in a ring secured within the casing which contains
the diaphragm) notches or recesses are made with which engages a spring or catch
secured to any suitable part (for instance to the ring which is slotted as aforesaid).
The free end of the spring catch that enters the notches or recesses in the ring allows
the ring to be rotated but as it comes opposite the notches or recesses the operator is
aware that the diaphragm or stop then presents a certain known and definite aperture.
in accordance with the recess or notch with which the catch is engaged.
The tube or mounting of the lens may be provided with divisions marked so that
the position of the stem corresponding with any given aperture may be ascertained
by reference to the scale or projections recesses or the like may be used instead of the
scale or in addition thereto so that by running the finger over them they may be
readily counted and the aperture thus ascertained in a dark place.
The accompanying Drawings illustrate a lens tube or mounting with a diaphragm
or stop constructed according to this Invention. Figure 1 being a longitudinal section
and Figure 2 a transverse section thereof. The other figures shew parts separately as
hereinafter described.
The lens tube or mounting A is of the usual size and is provided with a ring A³ to
which one end of the leaves B constituting the diaphragm or stop are centred by the
pins b entering holes in the said ring A³. Figure 3 shews the ring A³ separately in a
front view and section and Figure 4 shews one of the leaves B separately in plan and
edge view. The end of each of the said leaves B opposite that at which the pin b is
situated is provided with a pin 6ª projecting on the side opposite to that on which the
pin 6 projects.
These pins enter the slots c which extend radially from the inner circum- 1
ference of the ring C (shown separately in plan and section in Figure 5) to or
near to the outer circumference of the said ring which is strengthened by the angled
rim or ring e' which gives such strength as to allow the slots c to extend radially across
or nearly across the ring. To the said ring O a stem c³ is affixed (see Figure 1) the
said stem extending through slots a 63 in the ring A³ and lens mounting or tube A
respectively where the said stem is furnished with a pointer the coincidence of
which with projections or markings (as at a) on the mounting or tube A indicating
the degree of opening or aperture of the diaphragm or stop. In the ring A³ is
secured another ring D (shewn separately in plan and section in Figure 6) having
therein notches d corresponding like the projections or markings a to the degree of
aperture to which the diaphragm is adjusted the outer end of a spring E secured
at to the ring C) engaging with the notches d. As the ring C is moved round by.
the sten the radial slots c operate on the pins 6' of the leaves B and as the other-
ends of the said leaves are fixed by the pins 6 engaging in the holes in the ring A³
the said leaves are caused to approach to or recede from the axis of the lens tube or..
mounting and so contract or expand the aperture of the stop or diaphragm according
to the direction in which the ring C is moved the spring E riding along the edge of
the ring D and by engaging with the notches d indicating the degree of aperture
the said spring being sufficient to engage with the notches so as to indicate when any
set size of aperture is reached and prevent accidental alteration of the aperature
but not to interfere with the movement of the ring by the operator,
b

page_text: 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 :-
First. In diaphragms or stops of the kind described the actuating ring C having
a strengthening rim or ring and radial slots c therein opening from the inner cir-
cumference of the ring or thereabouts with which slots engage pins on the leaves
members or strips B of the diaphragm or stop substantially as and for the purposes
herein before described.
Second. In diaphrgms or stops of the kind described the combination with an
indicator or scale of a spring engaging with a notched ring for indicating the degree
of aperature and retaining the leaves members or strips of the diaphragm or stop in
their adjusted position substantially as herein before described.
Third. The arrangement and combination of parts constituting a lens tube or
mounting provided with a diaphragm or stop of the kind shewn substantially as and
for the purpose herein before described and illustrated in the accompanying drawings.
Dated this 21st day of November 1889.
J. H. JOHNSON & Co.,
Agents.