IMPROVEMENTS IN PULLEY RACKS FOR BLIND CORDS
Year: 1873

page_text: LETTERS PATENT to Henry Luther Hall, of Chicago, Illinois, United
States of America, now of No. 8, Southampton Buildings, London,
for the Invention of "IMPROVEMENTS IN PULLEY RACKS FOR BLIND
CORDS."
PROVISIONAL SPECIFICATION left by the said Henry Luther Hall at
the Office of the Commissioners of Patents, with his Petition, on
the 24th April 1873.
I, HENRY LUTHER HALL, of Chicago, Illinois, United States of
America, now of No. 8, Southampton Buildings, London, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN PULLEY RACKS FOR
BLIND CORDS," to be as follows:-
The said Invention relates to a device for blind cords, the chief object
of which is to secure a constant tension of the cord, and to retain the
Oblind in any desired position,

page_text: (1.) In the arrangement of the shank of the pulley bar and a spiral
spring within a case.
(2.) In a clamp frame provided with a set screw for receiving and
holding said case in the required position.
And (3.) In an automatic locking device for holding the cord, and
thereby retaining heavy blinds in any desired position.
The case is constructed of cast or sheet metal, by preference of semi-
cylindrical form, in cross section, and of two parts which are rivetted or
otherwise secured together.
same.
The shank or stem of the pulley bar surrounded by a spiral-spring is
placed in the semi-cylindrical case, and extends to the bottom of the
The spring presses against a pin fixed in the lower end of the
said shank, and against a rim on the inner side of the top of the case.
There is a aperture in the upper end of the said case through which
the shank of the pulley bar passes. The pulley is secured to an enlarged
end of the pulley bar above the case by means of a stud upon which it
revolves. Around 'the 'said case is placed a clamp frame provided with a
set screw, which 'clamp frame is secured to the window casing or other
convenient part of the woodwork in any suitable manner. The said case
is secured in the clamp frame by means of a set screw, and the outer
surface of the case may be ribbed to prevent any slipping of the screw.
The case is secured in the clamp frame in such a position that the
requisite tension is given to the blind cord, and any variation in the
length of the cord caused by the atmospheric changes or otherwise is
compensated for by the spring, and a constant tension is thereby
secured.
f:
The pulley bar for heavy blinds is provided with a locking device
consisting of a T head, which, by preference, is formed on the pulley
bar, and from one end of which a stud projects across the plane of the
pulley, and the opposite end of which is 'pivoted a dog or lever with a
serrated face on its heavy end' which falls near and is parallel to the said
stud. The opposite end of the lever or dog serves as a handle to lift the
serrated end of 'the same when it is required to lower the blind, the
blind cord being placed between the stud and the face of the serrated
plate. The serrated end of the lever or dog being the heaviest will press

page_text: upon the cord, and in case the tension spring should be insufficient to
sustain the weight of the blind the downward movement of the blind
cord causes the dog to force the cord against the stud, thus locking it
securely while the dog frees the cord when the blind is being raised.
This locking device is unnecessary when light or ordinary blinds are
employed, the tension of the spring is sufficient to sustain the weight
of the blind.
SPECIFICATION in pursuance of the conditions of the Letters Patent,.
filed by the said Henry Luther Hall in the Great Seal Patent Office
on the 24th October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
LUTHER HALL, of Chicago, Illinois, United States of America, now of
No. 8, Southampton Buildings, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of April, in the year of our
Lord One thousand eight hundred and seventy-three, in the thirty-sixth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Henry Luther Hall, Her special licence that I,
the said Henry Luther Hall, my executors, administrators, and assigns,
or such others as I, the said Henry Luther Hall, 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, tlio
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
PULLEY RACKS FOR BLIND CORDS," upon the condition (amongst others) that
I, the said Henry Luther Hall, my executors or administrators, by an
instrument in 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 Henry Luther Hall, do hereby
dealove the nature of my soid Invention and in what manner the same is

page_text: part of the woodwork in any suitable manner. The said case a is
secured in the clamp frame by means of the set screw i, and the outer
surface of the case may be ribbed as shown, to prevent any slipping of
the screw i. The case a is secured in the clamp h in such a position
that the requisite tension is given to the blind cord, and any variation
caused by atmospheric changes or otherwise in the length of the cord is
compensated for by the aforesaid spring, and a constant and.nearly equal
tension is thereby secured.
When my improved apparatus is used for heavy blinds the pulley bar b
is provided with a locking device, as shewn in Figures 3 and 4. For
this purpose I form or fix on the pulley bar 6' a stud ; which projects
across the plane of the pulley f. In combination with this stud I arrange
the dog k, whose lever ¹ is pivoted at ³ to the bar-b. The said dog has
a serrated face. The lever is so pivoted that the dog is on its heavy
end, which tends always to fall on the said stud, so that the cord will be
gripped between the stud and dog. The opposite end ³ of the lever
serves as a handle to lift the serrated end of the same when it is
required to release the cord to lower the blind. The end of the lever
carrying the dog being the heaviest the dog lies against the blind cord,
and in case the tension of the spring should be insufficient to sustain the
weight of the blind the downward movement of the said cord causes
the dog to force the same against the stud, thus locking it securely; but
the dog frees the cord when the blind is being raised. This locking
device is unnecessary when light or ordinary blinds are employed, the
tension of the spring being then sufficient to sustain the weight of the
blind.
If desired the pulley f may be dispensed with, and a stationary pin
used instead of the same.
Figure 5 illustrates the adaptation of my Invention to a form of rack
very commonly used. The shank or stem m passes freely through a
hole in the bracket 7, and has a screw thread extending from its
extremity to the shoulder m². Above this shoulder it has a fork which
encloses the pulley f. n is a thumb nut, which in this apparatus as
usually constructed rests against the bracket 7, the cord being tightened
or slackened as desired by turning this nut upon the screw. The
bracket projects from a plate A, which is securely attached to the
window frame by screws or nails o, as shewn. I adapt my Invention to

page_text: this apparatus by fitting the spiral spring c around the shank m, and
between the nut n and the bracket 1, as shewn.
Having thus fully described my said Invention, and the manner of
performing the same, I wish it understood that I claim,―
First. The apparatus consisting of a pulley mounted on a bar, whose
stem or shank is enclosed within a case and surrounded by a spring
placed therein, and apparatus as herein set forth and for the purpose
specified.
Second. The combination with the said apparatus of the clamp frame
and set screw, as hercin set forth and for the purpose specified.
Third. Providing the said apparatus with a locking device combined
with the other parts of the said apparatus, and operating as herein set
forth and for the purpose specified.
Fourth. The adaptation of my Invention to the apparatus shewn in
Figure 5, as herein set forth.
In witness whereof, I, the said Henry Luther Hall, have hereunto
set my hand and seal, this Nineteenth day of October, in the
year of our Lord One thousand eight hundred and seventy-three.
Witnesses,
J. R. HEBERT.
D. P. SECOR.
HENRY LUTHER HALL. (L.S.)