An improved Photographic Dark Blue.
Year: 1898

page_text: An improved Photographic Dark Blue.
THOMAS PETER BETHELL, 115, Islington, Liverpool, in the County of Lancashire,
Cardboard Box Manufacturer, do hereby declare the nature of this invention to be
as follows:
on
This invention relates to an improved arrangement for cheap dark slides
for photographic cameras, and consists of a plate holder, sheath and shutters.
The plate holder for a double dark slide is made by fixing
each side of a piece of cardboard, or other suitable material A, narrow
strips of cardboard, B3, B6, parallel to each other, about the same thickness as an
ordinary photographic dry plate, leaving sufficient space between B & B b, on each
side of A, to accommodate the dry plates.
At right angles & across one end of B & B, a piece of cardboard C, of the
same substance as BB6, is fixed on each side of A.
Over B, Bb, & C, I place a piece of cardboard or other suitable material D, out
of which a slightly smaller apperture has been cut, than that formed
by B, Bb, & C, when in position. A thumbhole is provided in 1), to facilitate the
removal of the plate, this arrangement when the several parts are suitably
secured, forms a rabbet or groove E, Ee, on each side of A, into which the dry
plate may slide & be held firmly. The top of the plate holder is covered with a
suitable fabric to exclude the light, when the plate holder is in the sheath F.
The sheath F, consists of a case made preferably of cardboard, covered with a
suitable material, with an apperture cut from each of its sides to correspond with
the apperture in the plate holder. The bottom of the sheath is closed, preferably
with a piece of wood, the full width of the plate holder & the required depth, with
a rabbet on each side, leaving a space in the centre sufficient to engage the two
dry plates & cardboard A, of the plate holder, this arrangement provides for the
shutter G to go below the bottom edge of the apperture of the sheath & effectually
excludes light when the shutter is closed.
The shutters G, fit between the two outer surfaces of the plate holder & the
inside of the sheath, so that when the plate holder with a shutter on each side is
inserted in a sheath, two consecutive exposures may be made, by first drawing up
the required shutter, then replacing it, withdrawing the whole of the dark slide,
turning it round & repeating the operation.
Dated this Thirty-first day of March 1898.

page_text: THOMAS PETER BETHELL, 115, Islington, Liverpool, in the County of Lancaster,
Box Manufacturer, 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 an improved arrangement for cheap dark slides for
photographic cameras, & consists of a plate holder, sheath & shutters.
The plate holder for a double dark slide is made by fixing on each side of a
piece of cardboard, or other suitable material A, narrow strips of card-
board, B, Bb, parallel to each other, about the same thickness as an ordinary
photographic dry plate, leaving sufficient space between B & B b, on each side of A to
accommodate the dry plates.
At right angles & across one end of B, Bb a piece of cardboard C of the same
substance as B, Bb is fixed, on each side of A.
Over B, Bb, & C, I place a piece of cardboard or other suitable material D, out
of which a slightly smaller aperture has been cut, than the space formed
by B, Bb &C when in position. A thumbhole is provided in I), to facilitate the
removable of the plate, this arrangement when the several parts are suitably
secured, forms a rabbet or groove E&E e, on each side of A, into which the dry
plate may slide & be held firmly. The top of the plate holder is covered with a
suitable fabric to exclude the light, when the plate holder is in the sheath F.
The sheath consists of a case made preferably of cardboard covered with a
suitable material, with an aperture cut from each of its sides to correspond with
the aperture in the plate holder. The bottom of the sheath is closed, preferably
with a piece of wood the full width of the plate holder & the required depth, with
a rabbet on each side, leaving a space in the centre sufficient to engage the
two dry plates & cardboard A, of the plate holder, this arrangement provides for
the shutter G, to go below the bottom edge of the aperture of the sheath &
effectually excludes light when the shutter is closed.
The shutters G, fit between the two outer surfaces of the plate holder & the
inside of the sheath, so that when the plate holder with a shutter on each side is
inserted in a sheath, two consecutive exposures may be made, by first drawing up
the required shutter, then replacing it, withdrawing the whole of the dark slide,
turning it round & repeating the operation.
The shutters G, may be made of either metal or cardboard, or a combination
of metal & cardboard or other suitable material. They may be of one rectangular
piece of material, or if cardboard is used, it may be creased at H, in such a manner
& position, that, when drawn up at the time of making the exposure, the upper
portion of G, may be turned down at right angles with the lower portion G, g.
The upper
& lower portion of shutters G&G, g, may be suitably covered with
metal, leaving the creasing in the cardboard uncovered, allowing the shutter to be
turned down as described above.
The shutters G, may also consist of a piece of cardboard creased at H, with
additional pieces of cardboard or metal suitably attached to the upper & lower
portion, the upper portion being so attached that, when the shutter is drawn up &
turned down at right angles with the lower portion, the portion J, may project over
the top portion of the dark slide, & if depressed when at right angles may form a
protection against light entering & spoiling the plate during a prolonged exposure.
The drawings refered to from A to G are those left with the Provisional
Specification.
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page_text: Having now particularly described & ascertained the nature of my said
invention & in what manner the same is to be performed, I declare that what
I claim is:-
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