IMPROVE- MENTS IN THE MANUFACTURE OF WINDOW BLINDS
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
POTTER BURT, of the Blackfriars Road, in the County of Surrey, Civil
Engincer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Thirtieth day of
November, One thousand eight hundred and fifty, in the fourteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Henry Potter Burt, my exors, adñiors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Henry Potter
Burt, my exors, admors, and assigns, or such others as I, the said Henry Potter
Burt, my exors, admors, or assigns, should at any time agree with, and no
others, from time to time and at all times during the term of years
therein expressed, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, and in the
Islands of Guernsey, Jersey, Alderney, Sark, and Man, and also in all Her
said Majesty's Colonies and Plantations abroad, my Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF WINDOW BLINDS;" in which said Letters
Patent is contained a proviso that I, the said Henry Potter Burt, shall
cause a particular description of the nature of. my said Invention, and in
what manner the same is to be performed, by an instrument in writing under
my hand and scal, to be inrolled in Her Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said

page_text: in part recited Letters Patent, as in and by the same, reference being there-
unto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Henry Potter Burt, do hereby declare that the nature of my said Invention,
and in what manner in which the same is to be performed, are fully described
and ascertained in and by the following statement thereof, reference being bad
to the Drawings hereunto annexed, and to the figures and letters marked
thereon, that is to say:-
'
My Invention relates to those descriptions of blinds which are generally
called Venetian blinds, and consists in making the laths of such blinds of
metal, embossed, or otherwise rendered uneven in surface.
My Invention also relates to the mode of suspending such blinds. The
laths of Venetian blinds are generally made of thin deal or other wood, and
are suspended by means of tapes and cords. The cords are carried over
pullies fixed in a batten above the blind, and after passing over other pullies
at one end of the batten the cords descend and are united together, so that
by pulling them both at the same time the blind may be raised and preserve
its parallelism while being raised. The blind is sustained when raised by
winding the cords, which are of very considerable length, upon hooks provided
for the purpose. The materials thus employed being of a combustible nature
these blinds afford no security against fire, but rather facilitate its progress
from one part of a building to another. They are also liable to rapid
destruction by insects, and by atmospheric action, especially in hot climates.
My Invention supplies the means for obviating these defects.
Figure 1, of the Drawings hereunto annexed, is an elevation on front view of
one of my improved blinds; Figure 2 is a vertical section of the same. The
same letters refer to similar parts in both Figures. A, A, are the laths made
of thin sheet iron, embossed with an ornamental pattern, by which means a
very light and stiff lath is obtained; B is a hollow metallic spindle or tube,
which turns in supports C, D, at the two ends, and carries the pullies E, E;
and F, and a ratchet wheel G. The laths A are connected at their edges by
the chains or cords H, H, which pass over and rest upon the spindle B, and
support the blind when lowered. Two other chains or wire ropes J, I, are
attached to the bottom lath, and pass up through the other laths, and are
attached to the pullies E, E. By turning the spindle B the two chains I, I,
are wound up simultaneously, and the blind is raised, and preserves its
parallelism in rising. The spindle B is turned by means of an endless cord or
chain K, K', passing round the pulley F, over a small pulley L, and under the
pulley M. By pulling either part K or K' of this cord the blind is raised or

page_text: lowered. To sustain the blind in any required position a pall N is employed,
which is pressed into the teeth of the ratchet wheel G by means of a spring P.
The pulley L is supported on the opposite end of the pall N, which turns on
the pin R. It will be seen that when the part K of the cord is pulled down-
wards the blind will be raised, and the pall N will be raised by each tooth of
the ratchet wheel as it revolves, and on releasing the cord K the blind will be
supported by the pall falling into the ratchet. When it is required to lower
the blind, the part of the cord K' is pulled, by which means the pulley L is
depressed, and the pall withdrawn from the ratchet wheel, which then revolves
by the action of the weight of the blind and the tension on the cord K'. The
moment the cord K' is released the pall N drops into the ratchet and stops
the motion, so that the blind is thus completely under the command of the
cord K, K. As the blind is required to be lowered when acting as an
obstacle to the progress of fire, it is not necessary that the cord or chain K, K',
should be of incombustible material, as its destruction would not alter tho
position of the blind. The same observations may apply to the chains I, I,
which may in some cases be advantageously made of easily combustible
material, so that if the blind happened to be raised, the destruction of these
chains or cords will allow the blind to descend, the laths remaining supported
as usual by the chains H, H, and the metallic spindle B. Where security
against fire is not required, the metallic laths may be suspended in the
ordinary manner in which wooden laths are now suspended. The spindle B
may be employed with the ordinary wooden laths in the same manner as with
the metallic laths herein-before described. The form of the pattern embossed
on the laths may be varied at pleasure, and in Figures 3, 4, 5, 6, 7, 8, 9, 10,
11, I have shewn some of such variations. Figures 3, 5, 7, and 9, are
elevations; and Figures 4, 6, 8, 10, 11, are sections. In Figures 7, 8, and
11, the embossing is in the form of corrugations, flutes, or undulations, and in
Figures 9 and 10 it consists of one single undulation or curve. The embossing
may be produced by any of the known methods of embossing metal sheets,
such as rolling, pressing, or stamping between dies. From the lower surface
of the plate being a counterpart of the upper surface it follows that the plates
fit one into the other when the blind is raised, and consequently occupy little
or no more space than would be occupied by flat sheets of metal of the same
thickness, while the stiffness of the laths is far greater than if they were
composed of flat plates. In Figures 9 and 10 I have shewn a method of
ornamenting the embossed plates by perforating them. The form and arrange-
ment of the perforations may of course be varied at pleasure, and they may be
formed by punching or drilling, either before or after the embossing, or by

page_text: forming the embossing dies or tools with suitable projections and indentations.
The embossing and perforating may be effected at one operation.
My improved blinds may thus be constructed of very elegant appearance, in
addition to their other advantages herein-before mentioned. The laths may
be made of various metals, such as brass and other alloys, steel, iron, zinc, or
iron coated with zinc or tin, and they may be painted, japanned, bronzed, gilt,
or otherwise ornamented at pleasure.
Having now described the nature of my Invention, and the manner in
which the same is to be performed, I wish it to be understood that I claim as
my Invention the constructing of Venetian blinds with laths of embossed sheet
metal, as herein-before described; I also claim tho suspending the laths of
Venetian window blinds by means of the spindle B, in the manner hercin-
before described, by which means the parallelism of their motion is insured,
and the multiplication of cords is avoided.
In witness whereof, I, the said Henry Potter Burt, have hereunto set
my hand and seal, this Thirtieth day of May, in the year of our Lord
•
HENRY POTTER (L.S.) BURT.
AND BE IT REMEMBERED, that on the Thirtieth day of May, in the
year of our Lord 1851, the aforesaid Henry Potter Burt came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Enrolled the Thirtieth day of May, in the year of our Lord One
thousand eight hundred and fifty-one.