mprovements in is Diap
Year: 1894

page_text: Date of Application, 8th Mar., 1894
Complete Specification Left, 8th Dec., 1894-Accepted, 9th Feb., 1895
mprovements in is Diap
ARTHUR SAMUEL NEWMAN and JULIO GUARDIA Manufacturers of Scientific
Apparatus 92 Shaftesbury Avenue London W. do hereby declare the nature of this
invention to be as follows:-
1
Our invention relates to improvements in iris diaphragms, such as are used in
photographic lenses and other optical appliances. In many cases it is necessary
to construct diaphragms occupying a very small space, to allow them to be inserted
between lenses or other arrangements without touching or interfering with the same,
more especially in the case of the recently introduced photographic lenses known
by the name of Anastigmats and Dopple-anstigmats and in which the space between
the lenses is very small. In carrying out our invention we construct the diaphragms
of a pivot-plate, driving-plate, and a number of leaves in the usual manner, but
instead of pivoting and driving the leaves by the usual methods, we have devised
certain improvements and these constitute our invention, which we now proceede
to describe.
In diaphragms as hitherto constructed, it has been usual to rivet or otherwise fix
the pivots and driving pins into the leaves, in such a manner as to let the side of
the leaves away from the pins, be quite smooth, to allow them to slide the one over
the other without friction.
Owing to the necessary thinness of the leaves this has been attended with some
difficulty. Or in other cases where the pivots or driving-pins are not fixed into
the leaves, but into the moving or fixed plates, the thickness of the whole arrange-
ment is increased by the length of the said pics. Our method of obviating these
difficulties is as follows. The leaves of our diaphragm are so arranged that a piece
of the metal is bent at right angles to the plane of the leaf, in such a manner that
a line drawn along the bend, being produced, shall approximately cut the centre of
the pivot on which the leaf turns. This bent up piece takes the place of the usual
driving-pins.
To construct our pivots we stamp or otherwise form a projection consisting of a
piece of the leaf, and fit the same into a corresponding depression in the pivot plate.
This projection may have a pivot hole in its centre, and a corresponding pin may
be provided in the corresponding depression, the top of the said pin being flush
with the surface of the pivot-plate.
To construct the driving plate, we drill or otherwise form a number of holes
surrounding the aperture of the diaphragm, and cut suitable slots into the same,
the turned up edges of the leaves being allowed free play angularly and lengthwise
in the slots.
1 1004
J. GUARDIA.
ARTHUR S. NEWMAN.

page_text: We, ARTHUR SAMUEL NEWMAN, and JULIO GUARDIA, both of 92 Shaftesbury
Avenue, London, Scientific Instrument Makers, 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, that is to say:
This invention relates to improvements in what are known as iris diaphragms
such as are commonly used in connection with photographic lenses and other optical
apparatus and which consist of a number of specially shaped leaves superposed one
above another and so mounted that by the partial rotation of a driving plate they
are caused to move inwards or outwards simultaneously towards or away from the
centre of the apparatus in such a manner that their inner edges form a more or less
perfect circular opening varying in diameter according to the relative position of
the parts. For this purpose the before mentioned leaves have hitherto, so far as
we are aware, been mounted or pivotted and also actuated by means of pins rivetted
or soldered thereto, such pins taking into holes or slots formed in the pivot plate
and driving plate. This arrangement necessitates the entire diaphragm apparatus
being of such a thickness as to preclude its use in certain cases where such apparatus
is required to occupy a very small space, for example where they are required to be
inserted between lenses the combinations of which are very close together, without
touching or otherwise interfering therewith. The photographic lenses recently
introduced and known as Anastigmats and Doppel-anastigmats more especially
require that the diaphragm apparatus shall be very thin.
According to our invention we so construct our diaphragm apparatus as to reduce
its thickness to a minimum and at the same time simplify and improve its
construction.
In the accompanying drawings Figure 1 represents a face view of a diaphragm
apparatus constructed in accordance with our invention, Figure 2 a similar view
with the driving plate removed, Figures 3 and 5 face views, and Figures 4 and 6
corresponding sectional views showing our improved method of pivotting the leaves
to the pivot plate.
Similar letters of reference relate to like parts in all the figures of the
drawings.
A are the leaves pivotted at B to the pivot plate C. D is the driving plate
adapted to be rotated on the pivot plate C'in a manner well understood in connection
with iris diaphragm apparatus of ordinary construction, by means of levers, handles
or other suitable or well known devices not shewn in the drawings. E is the central
opening which is to be covered or uncovered by the leaves A as required. F are
holes corresponding in number to the leaves A. and formed around and close to the
internal edge of the driving plate D. G are slots cut through the metal of the
driving plate D between the holes F and the internal edge of such plate as shown
in Figure 1. Each of the leaves A has a portion of its edge turned up so as to
form a flange H at right angles to the plane of the said leaf, the said flange H
being more or less radial to the pivot B on which the leaf turns. The flanges H of
the leaves A take into the slots G in the plate D so that when the latter is rotated
more or less, in the usual manner it turns the leaves A on their pivots B by action
of the slots G on the flanges H, so as to increase or decrease the diameter of the
opening E according to 'the direction in which the said plate D is rotated, in the
manner well understood in connection with the well known iris diaphragm apparatus.
It will be understood that the holes F in the plate D allow of the free movement
angularly and lengthwise of the flanges H as the plate D is rotated.
The leaves A may be pivoted to the pivot plate C by means of pins B (see

page_text: 1
Figure 2) screwed into and projecting therefrom, the leaves A passing freely over
and turning on such screwed pins or other projections. But, we prefer. to employ
one or other of the special methods of pivotting the leaves A illustrated in
Figures 3 and 4, or 5 and 6 of the drawings. In the method shewn in Figures 3
and 4, an annular recess B' is formed in the plate C, leaving the central part. B
standing up as a pin in the recess B', the top of the part B being preferably about
level with the face of the pivot plate C. The leaf A. is recessed as shown by
stamping or otherwise, and in the centre of the recess is formed a hole adapted to
pass over the pin B2 in the pivot plate C. The top of the pin B2 may then be
rivetted over slightly at its edges so as to prevent the easy withdrawal or removal
therefrom of the leaf A.
Or the leaves A may be pivotted to the plate C in the manner shewn in
Figures 5 and 6 in which a hole is formed through the plate C and slightly tapered
from the, under or outer side as shewn. A corresponding hole is drifted through
the leaf A and the drifted or projecting metal A¹ thereby produced is then passed
into the tapered hole in the plate C and further drifted or opened out into a conical
form so as to be held or retained in such hole as shewn in Figure 6.
When the pivot plate is sufficiently thin the hole need not be tapered but the
drifted part A of the leaf may be passed through the hole and rivetted over at the
back; or when the plate is too thick for this to be done, a recess may be formed
in the back thereof and the drifted part of the leaf rivetted over in the said
recess.
It will be understood that by the employment of either of the methods of
pivotting the leaves A described and shewn in Figures 3 to 6 the said leaves A
are so attached to the pivot plate C that no parts of such pivots project beyond
the upper surface of the leaves A. And that as the flanges H of the leaves A
project into the slots G in the driving plate D, the space between the parts C
and D of the apparatus need only be equal to the combined thickness of the super-
posed leaves A allowing the necessary additional space for their more or less free
movement. Consequently the entire thickness of the apparatus is reduced to a
minimum, and may therefore be employed under conditions which would render the
use of diaphragm apparatuses as hitherto constructed impossible. Moreover by
avoiding the necessity of attaching pins or pivots rivetted or soldered to the
leaves A we are enabled to use thinner metal for such leaves, and the liability of
the pius or pivots to be damaged during the process of blacking or otherwise
finishing the leaves is entirely obviated.
We have hereinbefore described the pivot plate on which the leaves A are
mounted as being fixed, and the driving plate provided with the holes F and slots G
as rotating; but it will of course be understood that this may be reversed if
desired without departing from our invention.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed we declare that what
we claim is :-
First. In an iris diaphragm apparatus forming the leaves A with driving flanges
or projections H shaped out of the metal of the leaves themselves, substantially as
described and for the purpose specified.
Second. In an iris diaphragm apparatus a pivot plate C, leaves A provided with
driving flanges or projections H, and a driving plate D having holes and slots G,
adapted to receive the said flanges or projections H, combined, arranged and
operating substantially as described with reference to Figures 1 and 2 of the
drawings.
Third. In an iris diaphragm apparatus pivotting the leaves to the pivot plate
by means of pins standing up in recesses formed in such plate, substantially as
described with reference to Figures 3 and 4 of the drawings.
Fourth. In an iris diaphragm apparatus pivotting the leaves to the pivot plate

page_text: by means of projecting parts formed out of the material of such leaves and secured
in holes in the pivot plate, substantially as described with reference to Figures 5
and 6 of the drawings.
Fifth. The improvements in iris diaphragm apparatus substantially as described.
Dated this 8th day of December 1894.
A. S. NEWMAN,
J. GUARDIA,
Per W. H. Beck,
115, Cannon Street, London, E.C., Agent.