IMPROVED VENETIAN BLINDS
Year: 1871

page_text: LETTERS PATENT to Alexander Porecky, of No. 25, Broke Road,
Dalston, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVED VENETIAN BLINDS."
PROVISIONAL SPECIFICATION left by the said Alexander Porecky at
the Office of the Commissioners of Patents, with his Petition, on the
21st January 1871.
of the
I, ALEXANDER PORECKY, of No. 25, Broke Road, Dalston, in the
County of Middlesex, Gentleman, do hereby declare the nature,
said Invention for "IMPROVED VENETIAN BLINDS," to be as follows:-
1. My Invention consists in making the whole or almost the whole of a
Venetian blind out of one sheet or piece of calico, canvas, linen, or paper,
or of paper and one of the other materials combined, or any other
suitable material having the required dimensions, which as regards
width is to be determined by the size of the blind, and as to length, by
the plan or system upon which it is to be constructed, there being
four different modes of forming the shading parts according to my
Invention.

page_text: "
First system. I take a sheet of any of the materials above indicated,
having the full width and a little over twice the length required for the
blind, double it exactly in two lengths, and join the ends together,
leaving the sides open. I then stretch it out evenly so that one sheet
shall lay flat on the other, and mark off a margin or border on all four
sides of suitable width; those at the top and bottom I shall designate
as end borders, and those along each side as side borders. Across the
space between the side borders I form a series of oblong apertures all of
equal width and at equal but a little wider intervals, all extending their
lengths parallel with each other and with the end borders from one side
border to the other. This I effect by cutting out of both sheets at the
same time oblong pieces or strips of the desired dimensions at the
required intervals. I have thus got an endless sheet forming a double
blind provided with apertures at certain intervals surrounded by the side
and end borders, and having all the corresponding parts exactly opposite
each other. I then take two boards or laths somewhat similar to those
used as top and bottom boards in the construction of the common
Venetian blinds of the length necessary for the width of the blind, while
their width is to be the same as that of an interval and undoubling and
extending the end borders at each end, so that the end border of the
upper and its corresponding one of the under sheet shall be in the same
plane, I fit or mount it on the surface of the board, and expressly in
such a manner that the line which forms the boundary between the two
sheets shall exactly meet the middle of the width of the board, and half
the width of the board be covered by the end border of one sheet, and
the other half by that of the other, and in which position it is to be
fastened by nailing, pasting, or gluing. The top board is then provided
with the shading tapes or bands and suspended on the rollers of the
fixed headpiece in the usual way. Now it will be seen that when
suspended and the surfaces of the end borders are in a horizontal plane
one sheet will be in front of and be distanced from the other by the
width of the boards, and the side view will present an oblong the long
sides of which are formed by the edges of the sheets, and the narrow
sides by the ends of the top and bottom boards, and in which case the
apertures of the one sheet will be exactly opposite to those of the other,
but if the boards are balanced so that their surfaces are in an inclined
plane, and a side view presents a parallelogram, one sheet will be drawn
upwards and the other downwards, and consequently the intervals or
spaces between the apertures of one sheet will be brought partially

page_text: opposite to the apertures of the other, and vice versa, and the greater
the incline of the surface of the boards the more the shading and the
closer the sheets will be brought to each other, so that when the surfaces
of the boards are vertical or nearly so the shading will be complete, the
apertures being then wholly closed by the intervals. As to the raising and
lowering of the blind it can be done in the usual way, but with a double
set of cords placed outside each sheet so as to keep them together when.
drawn up, or it can be mounted on a roller instead of boards the circum.
ference of which is to be double the width of an interval, in which case
it can be drawn or rolled up as the common roller blinds.
Second system. I take a sheet of material as before of the required
dimensions, double it exactly in two lengths, and join the ends as before,
and having marked off the margins or borders I form the apertures by
detaching the oblong pieces from both sheets at the same time as before,
but on three sides only, namely, the two narrow sides along the side
borders, and the lower long side from one side border to the other, leaving
each flap so formed attached or suspended by the upper long side to the
interval, which intervals may in this system be much narrower than
the apertures. I then take each pair of flaps, namely, that of the upper
and its corresponding one of the under sheet and sew or otherwise join
their detached long sides together. I then take two boards as before,
each of the same width as that of a pair of flaps when joined together, for
instance, if the width of each flap be one inch the pair when joined will
be a little less than two inches because of the overlapping required for the
joining, and consequently that width will be the measure for the width
of the boards, one of which I fit and fasten at each end as before. It
will be seen that when the blind is suspended and the surfaces of the
boards are in a horizontal plane all the surfaces of the flaps will be
horizontal too, and consequently the apertures of the one
opposite to those of the other, but if the surfaces of the boards be in an
inclined plane those of the shading flaps will be also in a similar plane,
and thus partially shade the apertures, in short, in whatever position and
direction the boards are placed the same will be assumed by the flaps,
so that when the surfaces of the boards are vertical or nearly so, so
will be those of the flaps and thus completely shut out the light.
sheet will be
Third system. I take a sheet of material as before of the full width
and a little over the length required for the blind, mark off the borders
and form the apertures, leaving the flaps attached by their upper sides as

page_text: before. These flaps I render by any advisable process firm and stiff to
preserve their straight and flat form. I then take two boards as before
the width of each of which must be exactly that of a flap and fit and
fasten, one board to each end, border. I then take a pair of bands or
tapes each of the same length and strength as the side borders and place
them at a convenient distance from and parallel with each other, the
ends of each of which I fasten to the top and bottom boards, respectively
in such a manner that the length of the bands between the free edges
of the boards shall be equal to that of the side borders between the
opposite edges of the boards, then the detached long sides of the flaps are
to be joined by their edges to the bands at the same distance apart as
their attached sides are from each other, for instance, if the width of
the apertures be two inches and the interval between them one incli,
then the edges of the detached long sides of the flaps must be joined to
the bands at a distance of three inches from each other. The blind so
constructed will produce the like effects under similar changes of the
position of the boards as in the foregoing systems.
Fourth system.-I take a sheet of one of the materials before indicated
of the full width and about one foot over three times the length required
for the blind, mark off the borders, and I form the apertures by cutting
out oblong pieces at intervals of more than double the width of an
aperture. I then take each of the intervals between the apertures and
double or fold them throughout their whole length, that is to say, the
whole width of the blind, sewing or pasting them together, and keeping
them in shape by any practicable means, and fitting and fastening the
boards to the end borders as before, bringing the whole, videlicet, the
top and bottom boards and the tucks or folds in connection by a pair
of bands which I fasten at the proper distances in every respect as
before.
Finally. It is to be remarked that in case of wide blinds I leave one
or more bands in addition to and parallel with the side borders so as to
give more support to the whole system of intervals and flaps. The
foregoing systems are also applicable for short or half blinds in which the
shading parts are vertical.
•

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Porecky in the Great Seal Patent Office
on the 21st July 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
PORECKY, of No. 25, Broke Road, Dalston, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of January, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and graut unto me, the said Alexander Porecky, Her special licence
that I, the said Alexander Porecky, my executors, administrators, and
assigns, or such others as I, the said Alexander Porecky, my executors,
administrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVED VENETIAN BLINDS,"
upon the condition (amongst others) that I, the said Alexander Porecky,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and scals, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office. within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alexander Porecky, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement, that is to say :-
My Invention consists in using calico, canvas, linen, paper, or paper
and one of the other materials combined, or any other woven or felted
material, in the construction of Venetian blinds instead of laths as
commonly used, and in making the whole or almost the whole of a
Venetian blind in one piece or sheet of material, or in two sheets,
according to the plan of construction adopted.
If any of the above indicated materials are to be used for constructing
Venetian blinds in the usual way, videlicet, in separate strips, connected

page_text: by bands, all that is to be observed is, firstly, that to impart to the strips
the stiffness necessary for keeping them straight with the least possible
weight I make them of a corrugated or fluted form, or I run a wire
along the edges, or adopt any other plan suitable for that purpose; and,
secondly, that the bands for directing their position are to be joined
direct to the edges of the strips, thereby dispensing with the cross
tapes.
But if the blinds are to be made out of a single or double sheet there
are different systems of construction, of which I shall describe four.
First system. I take two sheets of any of the materials above
indicated, each having the full width and a little over the length required
the blind, or I take one sheet of the full width and a little over twice
the length and double it exactly in two lengths, and in either case join
the ends together, leaving the sides open. I then stretch the sheets out
evenly so that one sheet shall lay flat on the other and mark off a margin
or border on all four sides of about an inch wide, and in case of wide
blinds I mark out one or more bands equidistant from and parallel with
the side borders. The borders at the top and bottom I shall designate
as end borders, and those along each side as side borders, and the bands
between the side borders as intermediate bands. Across the space
between the side borders or intermediate bands, as the case may be,
I form a series of oblong apertures all of equal width and at equal but
a little wider intervals or distances apart, all extending their lengths
parallel with each other and with the end borders from one side border
or intermediate band to the other side border or intermediate band.
This I effect by cutting out of both sheets at the same time oblong
pieces or strips of the desired dimensions, say, about three-quarters of
an inch wide at intervals of about an inch from each other. I then
take two laths or boards similar to those used as top and bottom boards
in the common Venetian blinds, each of the same length as the width
of the blind, while their width is to be the same as that of an interval
or distance between two apertures, and undoubling and spreading the
end borders so that the end border forming part of the upper and that
belonging to the under sheet shall be in the same plane. I fit and
fasten them to the surface of the boards, which boards I place either
inside or outside the sheets, one at each end, but in every case they
must be placed so that the boundary line between the two sheets shall
lay exactly along the middle of the width of the board, and half the

page_text: width of the board be covered by the end border of one sheet and the
other half by that of the other, and the length of each sheet between
the edges of the boards be exactly the same. Now it will be seen that
when the blind is suspended or in any way extended and the surfaces
of the boards are at right angles with the sheets, the sheets will be
distanced from each other by the width of the boards, and a side view
will present an oblong, the long sides of which will be formed by the
edges of the sheets and the narrow sides by the ends of the boards, in
which case the apertures of one sheet will be exactly opposite those of
the other, but if the boards are not at right angles with the sheets, and
a side view presents a parallelogram, the sheets will be shifted in opposite
directions, and the intervals of each sheet will be brought more or less.
opposite to the apertures of the other, and the greater the incline of the
surface of the boards the nearer the sheets will be brought to each other
and the more complete will be the shading.
As to effecting the changes of position of the boards and sheets, it is
donc in the usual way, videlicet, by providing the top board with the
shading tapes or bands by which the blind is to be suspended on the
rollers in the fixed head piece.
Second system. I take two sheets, or one sheet, of the same sort of
material and of the dimensions as above indicated, mark off the margins
or borders and form apertures as before, but while in the foregoing
system the intervals must be wider than the apertures, forming as they
do in that system the shading parts, in this system they may be of any
convenient width, say, about half an inch. The apertures in this system
I form by detaching the oblong strips at three sides only, videlicet, the
two narrow sides along the side borders or intermediate bands and one
long side from one side border or band to the other, and leaving the
flaps thus formed attached to the intervals by the other long side; I then
take two boards as before, the lengths of each the same as the width of
the blind, while their width is to be from one inch and a half to two
inches, fit and fasten the blind to them as in the foregoing system; I
then take each pair of flaps, namely, those of the one sheet and the
corresponding flaps of the other sheet and sew or paste or otherwise
join their detached long sides together, so that each pair of flaps when
joined shall be of exactly the same width as the boards.. It will be seen
that when the blind is suspended and the surfaces of the boards are in
a horizontal plane all those of the flaps will be horizontal also and,

page_text: consequently the apertures between the flaps will be fully open, but if
the surfaces of the boards be inclined those of the shading flaps will be
also in a similar plane and direction and thus partially shade the aper-
tures, in short, in whatever position and direction the boards are the
same will be assumed by the flaps, so that when the surfaces of the
boards are vertical or nearly so, those of the flaps will be so too, and
thus completely shut out the light.
Third system. In this system I use only one sheet of material of the
width and a little over the length required for the blind, mark off the
borders from the apertures, and leave the flaps attached by one of their
long sides as before.. These flaps I render firm and stiff by any advisable
process, but in preference to any other by pasting or gluing them within
the folds of doubled strips of glazed or varnished paper or other suitable
material, and which are to be a little wider than the flaps so as to exceed
the width of the apertures. I then take two boards the width of each
of which must be exactly the same as that of a flap, and I fit and fasten
one board at each end of the blind. I then take a pair of bands each
of the same length and pliability as the side borders and attach them
at a convenient distance from and parallel with each other, the ends of
which I fasten to the boards at each end of the blind in such a manner
that the lengths of the bands between the free edges of the boards shall
be equal to those of the side borders between the opposite edges of the
boards, then the detached long sides of the flaps are to be joined by their
edges to the bands at the same distance apart as their attached sides are
from each other, for instance, if the width of the apertures be two inches
and the interval between half an inch then the edges of the detached
long sides of the flaps must be joined to the bands at a distance of two
inches, and a half from each other. The blind so constructed will
produce the like effects under similar changes of the. position of the
boards as in the foregoing system.
Fourth system. I take a sheet of one of the materials before indicated
of the width and about one foot over three times the length required for the
blind, mark off the borders and form the apertures by cutting out oblong
pieces at intervals of more than double the width of an aperture. I then
take each of the intervals and fold them throughout their whole length,
that is to say, the whole width of the blind, sewing or pasting the folds
together and keeping them in shape by any practicable means, and fitting
and fastening the boards to the ends of the blind as before, bringing the

page_text: whole, videlicet, the boards and the tucks or folds, in connection by bands
which I fasten at the proper distances in every respect as in the fore-
going system. The blinds can be raised and lowered and the shading parts
directed by cords in the ordinary way, the cords for raising and lowering
passing through eyelet holes in the flaps for the purpose in each of the
three last-mentioned system, and in the last-mentioned system I use a
double set of cords for that purpose which I pass through eyes attached
to the edges of the intervals of each sheet either inside or outside.
I do not confine myself to the particular sizes given for the borders,
bands, apertures, and intervals, flaps, or shading parts, nor to the mode
or order of proceeding for effecting the desired object in the construction
of the blinds. Neither do I mean by one sheet that the blinds shall be
without scam as materials of less dimensions than the size of the blinds
may be joined together so as to form one sheet or piece.