Improvements in Combined Instantaneous and Time Shutters for Photographic Cameras.
Year: 1889

page_text: Date of Application, 13th May, 1889
Complete Specification Left, 13th Feb., 1890-Accepted, 15th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Combined Instantaneous and Time Shutters for
Photographic Cameras.
1, JOHN THOMAS DANIELS, of 14 Smith Street, Northampton Square, E.C.,
mathematical instrument maker, do hereby declare the nature of this invention to be
as follows:--
This invention relates to improvements in shutters for photographic cameras the
object being to combine simple instantaneous shutting mechanism with equally simple
devices whereby the shutter can be kept open and the lens exposed for any desired
length of time.
Around
The shutter which I propose to use consists of a rectangular piece of sheet
metal mounted in vertical guides fixed in front of the lens or object glass. On
the outer face of the shutter is a stud or button and on each of the vertical guides
is a similar stud or button these latter being placed horizontally opposite each other
and vertically above the stud in the shutter so that the three studs represent the
three corners of a triangle of which the apex represented by the stud in the shutter
is the lowest. For a reason which will be afterwards explained the upper studs
project further from the guide pieces than the lower one in the shutter.
the three studs is stretched an india-rubber ring which when free to act raises the
shutter and exposes the object glass. The shutter is however controlled by a
notched lever pivotted below the lens tube, the notch spanning a pin on the bottom
of the shutter in which position it is retained by a flat spring. The releasing motion
can be effected by pneumatic pressure or other device and the contraction of the
india-rubber ring jerks the shutter quickly upwards and retains no further hold on
the stud in the shutter as the latter falls in consequence of the lower stud lying in
a different plane from the two upper ones and the tendency of the ring to hang
vertically when free to do so. Thus released the shutter would fall under the
influence of gravitation but its downward motion is accelerated by a second india-
rubber spring which is stretched across its upward path and with which the stud
in the shutter comes in contact whereby its upward course is checked and a
rebounding motion imparted to it. For "time" exposures a vertical lever is pivotted
to the shutter slides or other convenient part the upper end of which is turned
inwards towards the shutter. To the lower end of this lever is hinged an arm
which can be connected to the catch lover which retains the shutter in its closed
position. As soon as the latter is disengaged by the pneumatic or other appliance
the shutter flies upwards but before it can descend the turned-in end of the side
lever has advanced sufficiently to intercept its downward motion and the operator
can thus obtain any desired period of exposure.
It must be understood that the details above mentioned may be modified without
departing from the main features of the invention.
JOHN THOMAS DANIELS.
COMPLETE SPECIFICATION.
Improvements in Combined Instantaneous and Time Shutters for
Photographic Cameras.
I, JOHN THOMAS DANIELS of 14 Smith Street, Northampton Square,. E.C.
Mathematical instrument maker, do hereby declare the nature of this invention and
in what manner the sanie is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to improvements in shutters for photographic cameras the

page_text: object being to combine simple instantaneous shutting mechanism with equally
simple devices whereby the shutter can be kept open and the lens exposed for any
desired length of time.
The
The shutter which I propose to use consists of a rectangular piece of sheet metal
mounted in vertical guides fixed in front of the lens or object glass. On the outer
face of the shutter is a stud or button and on each of the vertical guides is a
similar stud or button these latter being placed horizontally opposite each other
and vertically abovo the stud in the shutter so that the three studs represent the
three corners of a triangle of which the apex represented by the stud in the
shutter is the lowest. For a reason which will be afterwards explained the upper,
studs project further from the guide pieces than the lower one in the shutter.
Around the three studs is stretched an india-rabber ring which when free to act
raises the shutter and exposes the object glass. The shutter is however controlled
by a notched lever pivoted below the lens tube, the notch spanning a pin on the
bottom of the shutter in which position it is retained by a flat spring.
releasing motion can be effected by pneumatic pressure or other device and the
contraction of the india-rubber ring jerks the shutter quickly upwards and retains
no further hold on the stud in the shutter as the latter falls in consequence of the
lower stud lying in a different plane from the two upper ones and the tendency of
the ring to hang vertically when free to do so. Thus released the shutter would
fall.under the influence of gravitation but its downward motion is accelerated by a
second india-rubber spring which is stretched across its upward path and with
which the stud in the shutter comes in contact whereby its upward course is checked
and a rebounding motion imparted to it. For time exposures a vertical lever is
pivoted to the shutter sides or other convenient part the upper end of which is
turned inwards towards the shutter. To the lower end of this lever is hinged an
arm which can be connected to the catch lever which retains the shutter in its
closed position. As soon as the latter is disengaged by the pneumatic or other
appliance the shutter flies upwards but before it can descend the turned-in end of
the side lever has advanced sufficiently to intercept its downward motion and the
operator can thus obtain any desired period of exposure.
It must be understood that the details mentioned may be modified without departing
from the main features of the invention.
In the accompanying drawings Fig. 1 represents a front elevation of the exposing
apparatus in which the shutter is closed. Fig. 2 is a similar elevation with the shutter
open and fig. 3 is a side elevation thereof.
A is the cap of the sliding tube in which is fitted the object glass this cap being
provided with an opening B (see fig. 2) which can be closed by means of a shutter C
mounted in vertical guides D fixed to the front of the cap A. In the centre of the
shutter is a stud c projecting only a short distance from the face of the shutter and
in each of the guides D is fixed a stud d these latter studs being longer than the stude
for the reason hereinafter explained. At the bottom of the shutter is a small pro-
jection c¹ the upper surface of which is perpendicular to the face of the shutter whilst
the lower surface is bevelled and at one side of the shutter is a similar projection d²
the character of the surfaces being the reverse of the former that is to say the upper
surface is bevelled and the lower surface perpendicular to the face of the shutter. To
a bracket E fixed to the cap A is pivoted a lever F notched at its upper end, the
notch being for the purpose of receiving the projection c¹ on the shutter. C. The
lever F is formed of thin spring steel or any suitable material so as to bend outwards
with a slight pressure. The lateral movement of this lever is communicated at the
will of the operator by pneumatic pressure, air being forced into the india-rubber
bulb G which by its distention acts on a plate H fixed to the lever F and causes the
lever to release the projection ; on the pressure of air being removed the spring J
collapses the bulb G and returns the lever F to its normal position. K is an elastic
band which when passed around the studs c and d as shown in fig. 1 tends to draw
the shutter upwards as soon as the lever F releases the projection c¹. The sudden
jerk imparted to the shuiter by the tension of the band carries the stud c beyond the

page_text: studs & and the former stud becomes. thereby disengaged from the band and can pass
freely beneath the same when the shutter descends in consequence of the studs d being
longer than the stud c as hereinbefore mentioned. The upward motion of the shutter
is checked and its downward motion accelerated by means of an elastic ring L which
is extended over the guides D and can be adjusted to any position thereon so as to
vary within a very small limit, the time of the exposure.
.
On the upward movement of the shutter the stud c strikes against the ring or band L
deflecting the same slightly, the power being restored during the return motion in
sufficient degree to cause the bevilled face of the projection c¹ to spring the lever F
outwards and so engage with the notch therein. To prevent any possibility of the
shutter rebounding a slight brake spring e may be fixed so that the projection c¹ may
wedge against it in falling.
In order that the apparatus may be used as a time shutter when instantaneous
photographs are not desired a lever M omitted in fig. 3 is pivoted to the cap A at a
the upper end of which is turned inwards at a'. This lever is made of spring steel
or other suitable material so as to give way to the projection d² during the upward
motion of the shutter the bevelled edge of the said projection forcing the spring out-
wards whilst on the descent of the shutter the perpendicular face of the projection
comes in contact with the turned in end a' of the lever and retains the shutter,
leaving the object glass exposed for any desirable length of time.
The lever M may be connected with the lever F at the will of the operator by
means of a rod m one end of which is pivoted to the lower end of the lover whilst
the other is perforated so as to be readily connected or disconnected with a pin f on
the lever F.
For time exposures the two levers F and M are connected as shown in full lines
in figs. 1 and 2 but for instantaneous exposures the lever M is disconnected as shown
ata in dotted lines in figure 1.
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. The combination with the releasing mechanism of an instantaneous shutter of a
photographic camera of mechanism for prolonging the time of exposure, such
inechanism consisting of a lever M controlled by the releasing lever in such manner
as to engage with a projection such as d and so check the descent of the shutter C
substantially as described and illustrated in the accompanying drawings.
2. The combination with the shutter of a photographic camera of releasing lever F
and check lever M substantially as and for the purpose described and illustrated in the
accompanying drawings.
3. The improvements in combination with shutters for photographic cameras sub-
stantially as described and illustrated in the accompanying drawings.
Dated this 12th day of Fahr 1800
JOHN THOMAS DANIELS.