Improved Shutter for Photographic Apparatus
Year: 1898

page_text: Date of Application, 1st June, 1898
Complete Specification Left, 28th Feb., 1899--Accepted, 1st June, 1899
Improved Shutter for Photographic Apparatus.
I, OSCAR AUGUST ERICSSON, of Engelbrektsgatan 65, Gothenburg, in the King-
dom of Sweden, Mechanical Engineer, do hereby declare the nature of this inven-
tion to be as follows:-
This invention relates to improved instantaneous shutters for photographic
apparatus and more especially to shutters, in which the objective opening is closed
by one or more plates or valves, the object being to provide a shutter which differs
from those heretofore customary in that the shutter plates do not continue to
move with the same velocity when in their full open position, as whilst they are
progressing to and from the said position, but, on the contrary, move with a very
great velocity to and from their full open position, and remain stationary during the
longer or shorter time of exposure.
In the accompanying drawing a plan view is shown of an instantaneous shutter
arranged according to this invention.
On the plate a two shutter-plates b, are pivoted preferably about a common
fixed pivot a', as usual in devices of this kind, said plates being normally held
in the closed position by means of a spiral spring 62, or the like extended between
their rear ends and they are actuated by means of an arm or lever e pivoted on
a fixed pivot a². On to the free end of the arm one end of a blade spring e or
the like is fastened, whose other end is provided with a rim or projection running
through a hole in the arm and bevelled at its inner end, said pin or projection
being arranged to move between and co-operate with the opposed inner edges of
the valves b, 61, formed in the well-known manner.
in
This invention may be carried out in such manner that the arm is actuated
by means of a rod , or the like around which a spiral spring or the like is
placed, one end of the rod being pivotally connected with one arm of a lever f that
revolves about a fixed pivot ³, and whose other arm serves as a handle. The
other end of the rod d works in a corresponding hole in a rectangularly bent-out
part of the arm c, on which part one end of the spring rests, the other being
supported by a cross-piece attached to the rod d. The lever f is normally
kept in the position shown in the drawings by full lines by means of a spring f
A hook lever revolves on the fixed pivot a and serves to hold the arm
different positions, for which purpose the catch is provided with two ratchet
teeth g, co-operating with the projecting part of the arm c. The hook lever g
is normally held in its proper position by means of a spiral spring h, or the
like from which position it can be released by means of an extension provided
with two projections g³, gt corresponding to each of the teeth g¹, g² and co-operating
with a projection at the cross-piece . The working is as follows:-When
the outer end of the lever f is pressed down the rod d moves upward, whereby the
spring is compressed, so that it presses with great strength upon the arm c.
long as the projection of the arm e engages with the tooth g of the hook lever g,
the arm c however cannot move, but when the projection ³, glides up along the
As

page_text: projection the hook lever g is turned to the side, so that the tooth g¹ is at last
brought out of engagement, thus releasing the arm c. The said arm now moves
upwards until it strikes against the tooth g2. During this movement the plates b, bl
are separated by means of the pin of the spring e¹, so that they occupy their
open position. When the rod d is moved further upward by means of the lever f
the spring continues to press with great strength upon the arm c which, how-
ever, remains in its last position until the projection arrives at the top of
projection 9, when the arm c is again released and moves into the position indi-
cated in the drawing by dotted lines, during which movement the plates 6, 61 are
again brought in their closed position. When the lever f is let free the spring fl
pulls the said lever, the rod d and the arm e back to their original positions. On
account of the bevelled end of the pin and the yielding of the spring cl the said
pin now glides over the projecting parts of the opposed edges of the valves b, b',
so that these are not opened during the said movement.
The invention set forth is, of course, not limited to the special form described
and shown in the drawing, but can be modified in several ways without departing
from the spirit of the invention. For instance, the lever f can be dispensed with,
in which case the rod may be lengthened and provided with a button or any
suitable handle. The spring f¹ can be arranged in such a manner as to work upon
the lever for the rod d in the opposite direction. The shape and arrangement of
the valves b, b and the device for opening the same by means of the arm c may
of course also be modified at will only keeping the releasing device described. The
chief thing is that the shutters by means of some suitable mechanism are auto-
matically and very swiftly moved when opening or closing, but stand still during
the time of exposure.
Dated this Winst day of June 1898
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.
I, OSCAR AUGUST ERICSSON, of Engelbrektsgatan 65, Gothenburg, in the King-
dom of Sweden, Mechanical Engineer, do hereby declare the nature of this inven-
tion 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 improved instantaneous shutters for photographic
apparatus and more especially to shutters, in which the objective opening is closed
by one or more plates or valves, the object being to provide a shutter which differs
from those heretofore customary in that the shutter plates do not continue to
move with the same velocity when in their full open position, as whilst they are
progressing to and from the said position, but, on the contrary, move with a very
great velocity to and from their full open position, and remain stationary during the
longer or shorter time of exposure.
In the drawing accompanying the Provisional Specification a plan view is shewn
of an instantaneous shutter arranged according to this invention (Figure 1).
A second sheet of drawings filed with this specification illustrates the same con-
struction in further detail, of which

page_text: Figure 2 shews a section on the line A--B of Figure 1.
Figure 3 shews the upper part of Figure 2 on an enlarged scale, and
Figure 4 shews a side elevation of the lever actuating the shutter plates.
On the plate a two shutter-plates 6, 61 are pivoted preferably about a common
fixed pivot al, as usual in devices of this kind, said plates being normally held
in the closed position by means of a spiral spring 2, or the like extended between
their rear ends and they are actuated by means of an arm or lever pivoted on
a fixed pivot a². On to the free end of the arm cone end of a blade spring c¹ or
the like is fastened, whose other end is provided with a pin or projection running
through a hole in the arm e and bevelled at its inner end, said pin or projection
being arranged to move between and cooperate with the opposed inner edges of
the valves b, 61, formed in the well-known manner.
The
9
This invention may be carried out in such manner that the arm c is actuated
by means of a rod d, or the like around which a spiral spring d¹ or the like is
placed, one end of the rod being pivotally connected with one arm of a lever f that
revolves about a fixed pivot a³, and whose other arm serves as a handle.
other end of the rod works in a corresponding hole in a rectangularly bent-out
part of the arm c, on which part one end of the spring rests, the other being
supported by a cross-piece attached to the rod d. The lever f is normally
kept in the position shewn in the drawings by full lines by means of a spring f.
A hook lever g revolves on the fixed pivot a and serves to hold the arm & in
different positions, for which purpose the catch is provided with two ratchet
teeth g, g² co-operating with the projecting part of the arm c. The hook lever
is normally held in its proper position by means of a spiral spring h, or the
like from which position it can be released by means of an extension provided
with two projections g³, g corresponding to each of the teeth g¹g and co-operating
with a projection d³ at the cross-piece d. The working is as follows:-When
the outer end of the lever f is pressed down the rod d moves upward, whereby the
spring is compressed, so that it presses with great strength upon the arm c. As
long as the projection of the arm c engages with the tooth g¹ of the hook lever g,
the arm e however cannot move, but when the projection ³ glides up along the
projection the hook lever g is turned to the side, so that the tooth is at last
brought out of engagement, thus releasing the arm c. The said arm now moves
upwards until it strikes against the tooth g². During this movement the plates b, b¹
are separated by means of the pin of the spring e, so that they occupy their
open position. When the rod is moved further upward by means of the lever f
the spring continues to press with great strength upon the arm c which, how-
ever, remains in its last position until the projection arrives at the top of
projection g', when the arm c is again released and moves into the position indi-
cated in the drawing by dotted lines, during which movement the plates 6, 6' are
again brought in their closed position. When the lever f is let free the spring f¹
pulls the said lever, the rod d, and the arm c back to their original positions On
account of the bevelled end of the pin and the yielding of the spring el, the said
pin now glides over the projecting parts of the opposed edges of the valves b, b¹,
so that these are not opened during the said movement.
The invention set forth is, of course, not limited to the special form described
and shewn in the drawing, but can be modified in several ways without departing
from the spirit of the invention. For instance, the lever f can be dispensed with,
in which case the rod d may be lengthened and provided with a button or any
suitable handle. The spring f' can be arranged in such a manner as to work upon
the lever for the rod d in the opposite direction. The shape and arrangement of
the valves b, and the device for opening the same by means of the arm c may
of course also be modified at will only keeping the releasing device described. The
chief thing is that the shutters by means of some suitable mechanism are auto-
matically and very swiftly moved when opening or closing, but stand still during
he time of exposure.

page_text: 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. An instantaneous shutter mechanism for photographic purposes having one or
more shutters which are pushed into the open position by means of an actuating
device and automatically closed again, characterized by the arrangement that for
the purpose of effecting rapid motion out of the ready position into the open
position, and out of the open position into the closed position on the one hand,
and for the purpose of a short delay whilst in the open position on the other hand,
there is interposed between the presser bar serving to actuate the mechanism and
the arm serving to displace the shutters, a spring or the like which acts in com-
bination with a catch in such a manner that in the first phase of the motion the
said arm is hindered in its motion by means of a projection of the said catch, and
consequently the said spring is stretched until in consequence of the further motion
of the presser bar the release of the projection follows; in the second phase the
released arm in consequence of the tension of the said spring forces the closing
shutter equally into the open position, and in this position it is held fast by means
of another projection on the aforesaid catch; in the third phase the aforesaid
arm in consequence of the second projection is again checked in its motion and the
spring aforesaid is again stretchied until the check is again released through
the further motion of the said presser bar; and in the fourth phase the released
arm is rapidly projected in consequence of the tension of the spring into its final
position.
2. The improved instantaneous shutter device for photographic apparatus con-
structed and operating substantially as described with reference to the drawing
accompanying the Provisional Specification.
2214
P 13 1
1000
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester and Birmingham.