IMPROVEMENTS IN OR APPLICABLE TO APPARATUS FOR COVERING OR EXPOSING THE LENSES OF PHOTOGRAPHIC APPARATUS."
Year: 1879

page_text: LETTERS PATENT to James Blewitt Spurge, Analytical Chemist, and John
Whitcher, Photographer, both of South Street, Romford, in the County of
Essex, for the Invention of "IMPROVEMENTS IN OR APPLICABLE TO APPARATUS
FOR COVERING OR EXPOSING THE LENSES OF PHOTOGRAPHIC APPARATUS."
PROVISIONAL SPECIFICATION left by the said James Blewitt Spurge and
John Whitcher at the Office of the Commissioners of Patents on the 25th
September 1879.
"
JAMES BLEWITT SPURGE, Analytical Chemist, and JOHN WHITCHER, Photo-
grapher, both of South Street, Romford, in the County of Essex. IMPROVEMENTS
IN OR APPLICABLE TO APPARATUS FOR COVERING OR EXPOSING THE LENSES OF
PHOTOGRAPHIC APPARATUS."
This Invention relates to apparatus for covering or exposing the lenses of
photographic apparatus, the object being to provide means for alternately and
instantaneously exposing the lense of a photographic camera to the "object" to be
photographed in such manner that the air is not disturbed in front of the sensitized
plate and consequently dust from that cause is avoided, and further the working of
the apparatus is facilitated and any shaking or displacement of the camera after
focussing is avoided.
Essentially the apparatus consists of a pivot rod or spindle arranged free to turn
and parallel with the principal axis of the lense, and mounted in bearings, boxing,
or casing, attached to the sliding front of the camera, and upon the said parallel
pivot is secured a disc of surface dimensions sufficient for covering the lense. Also
upon the said pivot is secured a crank arm or toothed segment to which a rod,
toothed rack, or connection is secured, and also a spring for holding the crank arm
or segment of the pivot, so that the pivot is rocked or turned partially around, and
with it the covering disc so as to cover the lense. This is the normal position of
the cover,
and when the sensitized plate (or screen for focussing) is to be exposed
the crank arın or segment is acted upon by its connection, so as to partially rotate
the pivot and carry away the covering disc from the lense for such time only as
that the sensitized plate or the screen is to be exposed.

page_text: For actuating the crank arm or segment of the covering disc pivot there is
imparted to the connecting rod attached thereto a reciprocating or piston like
action for working the crank, said connecting rod or toothed rack working in
guides in the boxing. The piston action is effected variously by a band wheel and
shaft and cam, acting on the connecting rod, and worked by band connection by
the operator, that is to say, the band is secured at one point of the periphery of the
band wheel, so that by loosening or tightening the band the wheel and the cam on
its shaft will be actuated to operate the crank and lense cover. We would remark
that the parts are of such slight weight that comparatively little power is required
for actuating the apparatus, and hence, the liability of shaking or displacing the
camera after focussing is avoided.
Again the piston action of the connecting rod may be effected by means of a
flexible diaphragm or expanding receptacle to be filled with water or air, supplied
by tube in connection with a forcing apparatus or device of any required kind, such
as a hollow india rubber bulb, such as is employed for pneumatic bells or commu-
nicating apparatus such as have been used in omnibuses for actuating a gong or
bell, but when this tube and forcing apparatus and inflatable chamber is employed
(to which apart from its use in connection with our hereinbefore described improve-
ments we lay no claim), and according to this Invention a tap or valve provided
with a disc having a milled edge for facility of turning or pressing is introduced
between the compressible bulb or forcing apparatus and the connecting tube, so that
when the forcing of the liquid or air is effected to uncover the lense, the tap or
valve is closed so as to retain the cap or cover in an open position.
If the cover is made in parts, two or more parallel pivots will have to be used,
and in such case a band will be passed over swells or pullies on said pivots or other
connection to rotate same, but we prefer the single disc.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Blewitt Spurge and John Whitcher in the Great Seal Patent
Office on the 25th September 1879.
JAMES BLEWITT SPURGE, Analytical Chemist, and JOHN WHITCHER, Photo-
grapher, both of South Street, Romford, in the County of Essex. IMPROVEMENTS
IN OR APPLICABLE TO APPARATUS FOR COVERING OR EXPOSING THE LENSES OF
PHOTOGRAPHIC APPARATUS."
This Invention relates to apparatus for covering or exposing the lenses of
photographic apparatus, the object being to provide means for alternately and
instantaneously exposing the lenses of a photographic camera to the "object" to be
photographed, in such manner that the air is not disturbed in front of the sensitized
plate and consequently dust from that cause is avoided, and further the working of
the apparatus is facilitated, and any shaking or displacement of the camera after
focussing is avoided.
Essentially the apparatus consists of a pivot, rod, or spindle arranged free to turn
and parallel with the principal axis of the lense, and mounted in bearings, boxing,
or casing attached to the sliding front of the camera, and upon the said parallel
is secured a disc of surface dimensions sufficient for covering the lense. Also
upon the said pivot is secured a crank arm or toothed segment to which a rod,
toothed rack, or connection is secured, and also a spring for holding the crank or
segment of the pivot so that the pivot is rocked or turned partially around, and
with it the covering disc so as to cover or uncover the lense. When the sensitized
plate (or screen for focussing) is to be exposed, the crank arm or segment is acted
upon by its connection so as to partially rotate the pivot and carry away the
covering disc from the lense for such time only as that the sensitized plate or the
screen is to be exposed.
For actuating the crank arın or segment of the covering disc pivot there is im-
parted to the connecting rod attached thereto a reciprocating or piston like action
for working the crank, said connecting rod or toothed rack working in guides in
the boxing. The piston action is effected variously by a band wheel and shaft and
cam, acting on the connecting rod and worked by band connection by the operator,
that is to say, the band is secured at one point of the periphery of the band
wheel, so that by loosening or tightening the band, the wheel, and the cam on
its shaft will be actuated to operate the crank and lense cover..
We would remark that the parts of such slight weight that comparatively
little power is required for actuating the apparatus, and hence, the liability of
shaking or displacing the camera after focussing is avoided.
Again the piston action of the connecting rod may be effected by means of a
flexible diaphragm or expanding receptacle to be filled with water or air supplied
by tube in connection with a forcing apparatus or device of any required kind,
I such as a hollow india rubber bulb such as is employed for pneumatic bells or
communicating apparatus, such as have been used in omnibuses for actuating a
gong or bell, but when this tube and forcing apparatus and inflatable chamber
is employed (to which apart from its use in connection with our hereinbefore
described improvements we lay no claim); and according to this Invention a tap
or valve provided with a disc having a milled edge for facility of turning or
pressing is introduced between the compressible. bulb or forcing apparatus and
the connecting tube, so that when the forcing of the liquid or air is effected to.

page_text: uncover the lense, the tap or valve is closed so as to retain the cap or cover in
an open position for any required time.
If the cover is made in parts, two or more parallel joints will have to be used,
and in such case a band will be passed over swells or pullies on said pivots or
other connection to rotate same.
In order that the said Invention may be well understood, we have hereunto
annexed a Sheet of Drawings illustrative thereof, wherein Fig. 1 is a side view of
apparatus partly in section, the covering disc of the lense being shewn in dotted
lines and shewing the disc-carrying pivot actuated by a crank arm thereon through
a cam, and rod, and band wheel for partially rocking the covering disc pivot for
exposing the lense.
Fig. 2 is a like view of similar device but with the disc pivot actuated through
a toothed quadrant and rack.
Fig. 3 is, a front view of apparatus with covering disc made in two parts of
"crab-claw" shape, the two parts being fitted on and worked by two pivots, one
hollow, and the other a solid pivot working within the hollow one, the covering
disc being shown closed.
Fig. 4 is a like view in section shewing the cams and piston rods for working
the said hollow and solid pivots of the crab claw covering disc, which is represented
in dotted lines open.
Fig. 5 is a side view of apparatus shown in Figs. 3 and 4, the parts being in
position as when the crab claw cover is closed.
Figs. 4 and 5 represent a cam for working the pistons of the covering disc or
crab claw discs.
In the Figs. 3, 4, and 5, the apparatus is represented as provided with tubular
connection for operating the piston or lifting action by means of inflatable
receptacle for water or air, but said crab claw covering disc may be operated by the
lifting action of the cam represented in Figs. 4a and 5ª.
Figs. 5 and 6 represent the union and securing nut of the apparatus for
attachment to the sliding front of the camera.
Fig. 7 represents a compressible bulb fitted with valve or tap, a tap being
shown.
Fig. 8 represents an arrangement of apparatus with sliding covering, disc, and
lever apparatus.
A is a socket piece which fits over the lense of the camera, allowing the latter
to slide freely therein, and attached to the boxing B in which the actuating
mechanism works. In Fig. 1 a is the spindle parallel with the principal axis of the
lense upon which the covering disc shown in dotted lines is secured; b is a crank
on said spindle; c, rod connected with an arm d which arm d is mounted upon
a rocking spindle e, which carries a band wheel f actuated through a cord or
band g h is a spring for purpose of holding the covering disc before the lense.
When in use the cord g may be for convenience carried to the ground under a
direction pulley or pullies, or direct to the hand of the photographer, who when
focussing or exposing the sensitized plate for the picture will by a slight pull upon
the cord lower the disc instantaneously, and when desired again cover same upon
releasing the cord as the parts will by action of the spring / be returned to the normal
covered condition. The spring for this purpose may obviously be a spiral or other
spring attached to and acting upon the rod c, to hold it down in position shown.
In Fig: 2, the crank b is a toothed segment plate operated by rack c' working in
guides C2.
'
In Figs. 3, 4, and 5, a double acting screen or covering plates C, C1, of crab claw
shape is shown; a is a solid spindle carrying the half screen C; a', a hollow
spindle carrying the half screen C₁; c is vertically acting rod connected to crank
arm b of spindle a; and c', a like rod connected to crank arm b¹ of hollow spindle

page_text: a', lower extremities of said rods c, c¹, being pivoted either to arms as shown at d,
Figs. 1 and 2, or as shown in Figs. 4 and 5 to a plate i capable of rising and
falling. This rising and falling action of plate i may be effected by the inflatable
and collapsible bag k, or by the action of a cam / mounted beneath on a spindle m
capable of being rotated by hand wheelf and cord g. The bag will be inflated
by any desired forcing apparatus, forcing water or air through a tubular con-
nection.
.
The union and securing nut which we employ and have shown in Figs. 5 and 6
consists of a short tubular piece n provided with a flange n³ on inner side of
boxing B, and to a neck thereon the tube k¹ of the bag is bound; the outer
portion of the tubular piece n is screw threaded to receive a lock nut o. The outer
end of piece n is turned out to receive a tube p provided with shoulder p¹, and over
this tube p is placed the screw cap q, which is internally threaded to fit screw of
tubular piece n; a flexible washer 7 is provided to ensure air tightness. The free
piece of tube n between the boxing B and lock nut o is held in a hole in the
sliding front of the camera, and nut o locks the boxing tight thereto. The tube
connecting the inflatable bag with the forcing device is secured upon outer free end
of piece a.
The forcing apparatus as before stated may be of any desired kind, but
when a bulb such as is shown in Fig. 7 is used, a tap or valve s is employed and
provided with milled edged button, so that the operator may close in the liquid
or air within the tube and bag k by simple action of thumb and finger.
A modification of the double acting screen is shown in Fig. 8. The two parts
C, C¹, sliding in a rectangular framing D at the side of the boxing B and arranged
in front of the lense. The two levers t, t', are pivoted at t² and are connected by a
link u.
The spindle at extends across the boxing B and works in guides or
slots, and upon being raised by any of the previously described modifications of
apparatus the outer ends of the levers t, t¹, will be separated, and so separate the
two parts of the cover to expose the lense.
It should be remarked that in both the arrangements of the divided screen, the
parts in addition to being very light are at a balance in consequence of the weight.
of the falling portion of the screen acting to counterbalance the weight of the upper
or rising portion of the screen, therefore but little power is required to operate the
device and effect the unclosing of the lense. Again the action of the divided screen
being in opposite directions any tendency to shake the lense will be negatived.
Also, the meeting edges of the disc may be curved as shown, or so as to expose an
oval or rectangular opening, and that commencing from the centre of the lense.
Having now described the nature of the said Invention in such wise that the
same may be readily carried into practical effect, I claim,-
First. In apparatus for operating a covering disc for the lenses of a photographic
camera, the parallel spindle a carrying said disc mounted in boxing B and in
relation to the socket piece A, and operated by the wheel f, as herein described
and shown in Figs. 1 and 2 of the Drawings.
Second. The double crab claw covering disc C, C¹, operating to uncover the lense
from the centre, as and for the purpose substantially as herein set forth and shown
in Figs. 3 and 4 of the Drawings.
Third. The double spindles a, a¹, operated by cranks b, b', and connecting rods
c, c, carried on plate i and working the double covering disc C, C³, and operated
substantially as set forth and shown in Figs. 3, 4, 4ª, 5, 5º.
Fourth. The device represented in Fig. 8 for operating the double "centre-
opening" screen in parallel guides D, substantially as and for the purpose herein
set forth.
Fifth. The union piece for attachment of the boxing B with its socket piece A to
the camera, as herein described and shown in Figs. 5 and 6.
Sixth. The said union piece in combination with the tube, and the use of the
.

page_text: milled headed tap or valve s and liquid or air forcing device. substantially as set
forth.
In witness whereof, I, the said James Blewitt Spurge, for and on behalf of
myself and the said John Whitcher, have hereunto set my hand and seal,
this Twenty-fifth day of September, in the year of our Lord One thousand
eight hundred and seventy-nine.
Witness,
WALTER A. BARLOW,
6, St. Paul's Churchyard,
London,
E.C.
JAMES B. SPURGE. (L.S.)