Improvements in Photographic Roller Blind Shutter Cases or Frames, and in the Manufacture thereof.
Year: 1898

page_text: Date of Application, 9th Feb., 1898
Complete Specification Left, 8th Nov., 1898-Accepted, 10th Dec., 1898
PRUVIDIONAL DITUITIVATION.
Improvements in Photographic Roller Blind Shutter Cases or Frames,
and in the Manufacture thereof.
I, JOIN EDWARD THORNTON, of Rokeby, Oldfield Road, Altrincham, in the
County of Chester, Manufacturer, do hereby declare the nature of this invention
to be as follows; -
In constructing a shutter case according to this invention, I make the case
in two parts, viz., the front part forming the box, and the other part forming
the back with recess for fitting on the lens.
I prefer to use sheet aluminium for the construction, (or an alloy of this
metal) but it is essential that it should be of a sufficiently soft and ductile
nature to permit of being bent, pressed, or drawn to the right shape without
breaking.
The tools used and the process of working are such as are commonly under-
stood in the stamping trade.
The box itself consists of a front and four shallow sides, which is stamped
up from a single sheet to the right form and in such a way that all the edges
and corners are nicely rounded off, and a hole is stamped in the centre of the
front large enough to admit light to the lens. In the sides of this case I punch,
drill, or otherwise pierce the necessary holes for the screws and other fittings
belonging to the working parts.
The back is also made out of a single sheet, and is turned down on the four
edges to form a flange, which fits tightly into the aforesaid box. In order to
prevent the back pushing too far into the box, I form a bead or rebate on the
edge of this flange, either by suitable press tools or by milling it to shape after-
wards, or by any other suitable means. In the centre of the back I punch a
circular aperture corresponding with the one in the front of the box, and round
this aperture I form a very deep flange, at right angles to the back itself, to
admit the lens hood or tube. This flange is punched, pressed, or drawn out
of the solid sheet, and at the bottom edge of the flange I turn the metal inwards
again at right angles to the flange, thereby forming a projection or flange of
smaller diameter, which acts as a stop for the lens hood or tube, or for the
rubber moulding that is sometimes used for lining the aperture.
During the hereinbefore described operations the metal may be softened as
required to assist it to turn over easily.
"
Although in this description I have described the use of aluminium for con-
structing the shutter cases for this invention, it will be obvious that any other
suitable metal or material capable of being stamped, pressed, or drawn to shape
can be used, but aluminium is preferred because of its lightness, cheapness, and
ductile properties.
I use metal of sufficient thickness for the box and back to permit of screws
being inserted direct into the metal, for attaching the various fittings, which

page_text: could not be satisfactorily done with thin metal, whilst other metals would
produce boxes far too heavy if used sufficiently thick.
By an alternative plan, the boxes and backs may be cast separately in
aluminium or an alloy of same, and afterwards trimmed up and finished off.
The case may be finished in various ways. For aluminium I prefer to finish
it with a fine matt grained surface, produced by a revolving scratch brush,
or by the sand blast process, or by any other suitable means, or the surface may
be highly polished by revolving buffs or other means. I preserve the finely
grained surface by a coating of lacquer.
The surface may be decorated either by embossing with suitable dies, or by
the sand blast process in conjunction with a suitable stencil or other pattern,
or by printing on from raised type, which is preferably made of rubber, or by
painting, or other decorative process applicable to metal, and, in this way be
made to imitate mahogany or other materials.
As an alternative method the cases may be moulded out of papier mache
or various plastic materials, in suitable dies, instead of being pressed out of
metal, but constructed in the same form as above described.
Improvements in Photographic Roller Blind Shutter Cases or Frames,
and in the Manufacture thereof.
I, JOHN EDWARD THORNTON, of Rokeby, Oldfield Road, Altrincham, in the
County of Chester, 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 is designed to provide a light durable case or box for photo-
graphic lens shutters more particularly for what are known as time and
instantaneous shutters.
It consists essentially in stamping the shutter case in two parts from sheet
aluminium one part forming a box to carry the roller blind and the other a
back formed with a recess to fit into the lens.
It will be fully described with reference to the accompanying drawings.
Fig. 1. Front elevation.
Fig. 2. Elevation from back.
Fig. 3. Side elevation.
Fig. 4. Longitudinal section on line x-x.
Fig. 5. Transverse section on line y-y.
Fig. 6. Sectional elevation showing a modified form of construction
Fig. 7. Section of another modification.
The front part A of the case is of hollow box shape with four shallow
sides a, a, a, a, stamped or drawn from a single sheet of aluminium with
all the edges and corners rounded off and a central hole a through which
light is admitted to the lens.
In the sides are punched, drilled or otherwise formed small holes to receive
the screws and other fittings of the working parts. The sides are of sufficient
thickness to receive the screws but if desired the several holes therein may be
bushed with harder metal to form bearings for the rotating parts and. for the
attaching, screws.

page_text: The back part B is also stamped or drawn from a single sheet of aluminium
with four sides 61, 62, 63, 64, which fit into the interior of the front part A a
rebate or ledge b being formed to prevent it entering too far into the box A
and to form a joint therewith. The ledge b may be formed by suitable stamping
tools or may be milled or otherwise cut out. In the centre of this back part B
is punched or drawn a circular aperture C with a deep cylindrical flange c to
fit over the lens hood or tube. At the bottom the circular flange c is turned
inwards again at c' to form a projection or flange c¹ of smaller diameter which
acts as a stop for the lens hood or tube or for the lining of moulded rubber ar
other material frequently, used.
If desired the front part A in addition to the sides a¹, a², a³, at, may also be
stamped with the central cylindrical flange c to fit over the lens hood and the
back B be made flat to form a plate or cover for one side with a central aperture,
as in Fig. 6.
In another modification shown in Fig. 7 the edges 61, 62, 63, 64, of the part B
may be turned or bent inwards to fit into the edges a¹, a², a³, a³, instead of
being moulded or cut, (see Fig. 7).
During the operations of stamping or drawing the metal may be softened
or annealed to assist it to turn over easily.
The aluminium case may be finished in various ways. I prefer to finish it
with a fine matt grained surface produced by a revolving scratch brush or by
the sand blast process, or by any other suitable means, or the surface may be
highly polished by revolving buffs or other means. I preserve the finely grained
surface by a coating of lacquer.
The surface may be decorated either by embossing with suitable dies, or by
the sand blast processes in conjunction with a suitable stencil or other pattern,
or by printing on from raised type, which is preferably made of rubber, or by
painting, or other decorative process applicable to metal and in this way to be
made to imitate mahogany or other materials.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is;
-
1. A shutter case constructed by stamping from sheet aluminium in two
parts one part forming a shallow box to carry the roller blind and the other
part stamped with an internal cylindrical flange to fit onto the lens hood cr
tube substantially as described.
2. A shutter case constructed by stamping from sheet aluminium in two parts
one part formed with outer flanges to carry the blind and internal circular
flange to fit onto the lens hood or tube and the other part stamped flat with a
circular opening to form a lid or cover substantially as described.
3. A shutter case stamped or formed from sheet aluminium substantially as
described and shown with reference to either of, the accompanying drawings.
Dated this 14th day of October 1898.
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.