AN IMPROVEMENT IN APPARATUS EMPLOYED IN RAISING AND LOWERING VENETIAN BLINDS AND IN RETAINING THEM IN POSITION
Year: 1868

page_text: LETTERS PATENT to Joseph Avery, of 81, Great Portland Street,
Marylebone, in the County of Middlesex, for the Invention of " AN
IMPROVEMENT IN APPARATUS EMPLOYED IN RAISING AND LOWERING VENETIAN
BLINDS AND IN RETAINING THEM IN POSITION."
Sealed the 27th November 1868, and dated the 2nd June 1868.
PROVISIONAL SPECIFICATION left by the said Joseph Avery at the
Office of the Commissioners of Patents, with his Petition, on the
2nd June 1868.
I, JOSEPH AVERY, of 81, Great Portland Street, Marylebone, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "AN IMPROVEMENT IN APPARATUS EMPLOYED IN RAISING AND LOWERING
VENETIAN BLINDS AND IN RETAINING THEM IN POSITION," to be as follows:-
Apparatus has heretofore been applied to Venetian blinds for use in
raising and lowering them and for retaining them in position, in which
the lifting and lowering cords passed over guide pulleys carried by the
upper ends of levers, and thence downwards between the lower or tail
ends of such levers and the box or bracket containing these levers, so
that when the blind has been raised to its required position and the pull
on the lifting cords was removed the tendency of the weight of the blind

page_text: was to cause the tail ends of the levers to nip the cords sufficiently to
hold the blinds as required. The releasing of the lifting cords for the
lowering of the blinds was effected by drawing on a check cord attached
to a saddle capable of riding on the tail ends of the levers, but by the
use of such saddle the leverage is the shortest, and consequently the
power exerted is the least effective when the nip on the lifting cords
is the greatest, by which the exercise of very considerable force is
necessary to release the blinds.
The object of the improvement is to remedy this evil. For this
purpose I form the outer ends of the tails of the levers into eyes or
loops to receive the ends of a cross piece having a loop or other con-
nection to the upper end of the check string, by which the power
exerted will be more uniformly operative, and great facility will be
afforded in operating the blinds.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Avery in the Great Seal Patent Office
on the 30th November 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
AVERY, of 81, Great Portland Street, Marylebone, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of June, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Joseph Avery, Her special licence
that I, the said Joseph Avery, my executors, administrators, and assigns,
or such others as I, the said Joseph Avery, 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 makė use, éxercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "AN IMPROVEMENT IN APPARATUS EMPLOYED
IN RAISING AND LOWERING VENETIAN BLINDS AND IN RETAINING THEM
IN POSITION," upon the condition (amongst others) that I, the said
Joseph Avery, my executors or administrators, by an instrument in

page_text: Avery & improved apparatus for waising and Lowering venetian Blinds.
writing under my, or their, or one of their hands and seals, 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 Joseph Avery, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
Apparatus has heretofore been applied to Venetian blinds for use in
raising and lowering them and for retaining them in position in which
the lifting and lowering cords passed over guide pulleys carried by the
upper ends of levers, and thence downwards between the lower or tail
ends of such levers and the box or bracket containing these levers, so
that when the blind has been raised to its required position and the
pull on the lifting cords was removed the tendency of the weight of
the blind was to cause the tail ends of the levers to nip the cords
sufficiently to hold the blinds as required. The releasing of the lifting
cords for the lowering of the blinds was effected by drawing on a check
cord attached to a saddle capable of riding on the tail ends of the levers,
but by the use of such saddle the leverage is the shortest, and con-
sequently the power exerted is the least effective when the nip on the
lifting cords is the greatest, by which the exercise of very considerable
force is necessary to release the blinds.
The object of the improvement is to remedy this evil. For this
purpose I form the outer ends of the tails of the levers into eyes or
loops to receive the ends of a cross piece having a loop or other con-
nection to the upper end of the check string, by which the power
exerted will be more uniformly operative, and great facility will be
afforded in operating the blinds.
But that the Invention may be fully understood I will by the aid of
the accompanying Drawing proceed more fully to describe the means
pursued by me in carrying the same into effect.
DESCRIPTION OF THE DRAWING.
Figure 1 shows a front view of parts of a Venetian blind with my
improvement applied; Figure 2 is an end view of the same; Figures

page_text: 3, 4, 5, 6, 7, 8, and 9, show detail views of the apparatus separately.
In each of the Figures the same letters indicate corresponding parts.
a, a, are the laths of the blind; b, the top rail from which the laths
are suspended, and by which they are hung by screwing or otherwise
in the ordinary manner to the top of the window or other place to
which the blind may be applied; c, c, are the bands or tapes aided by
the cross bands c' by which the several laths are maintained at their
relative distances apart; these bands or tapes c pass in the usual way
up to the top lath a', which is supported by other bands c³ passing over
rollers supported on spindles, so as to revolve in the top rail b;
d, d, are the cords which pass through holes provided for them in the
respective laths to the bottom one, where they are secured by knots or
otherwise, so that by drawing those cords upwards they may raise the
bottom lath, and with that the succeeding ones from the bottom one
upwards to the height to which it may be desired for the time to raise
them. These cords d pass over pulleys d' which are supported to revolve
in the top rail b, and thence they pass along over the top rail 6 and over
pulleys e, each of which is supported in the upper end of a lever f.
These levers are supported to rock on a spindle f' carried by the
frame g, and at their lower or tail ends f* they are formed to be capable
of nipping the cords d passing over them between such ends and the
inner surface of the frame g, when the weight of the laths is allowed
to bear on the cords d, d, all which has heretofore been done, and
separately forms no part of my Invention. When it is desired to release
such blinds and allow them to descend from a state of suspension
another check cord h is drawn upon, this cord h being affixed at its
upper end to an eye i¹ formed in a descending part of the cross bar i,
the opposite ends of which according to my Invention pass through the
respective eyes f, or they may simply be loops formed in the tail ends f
of these levers f, such eyes or loops being of an elongated form, as
shown, and of a larger size on the inner surfaces thereof, or those
surfaces of the levers next each other than on the outer surfaces thereof,
by which the power exerted on the levers f to release the lifting cords d
will be more fully and instantly exerted, and the power of the check
cord will be more effectively operative.
Having thus described my Invention, I would have it understood that
what I claim is, the application of the connection of the check cords to
the tails of the levers by means of a bar or such like means passing

page_text: into eyes or on to loops formed in the ends of such tails, substantially as
explained.
In witness whereof, I, the said Joseph Avery, have hereunto sct
my hand and seal, this Twenty-third day of November, in
the year of our Lord One thousand eight hundred and sixty-
eight.
JOSEPH AVERY. (L.S.)