IMPROVE- MENTS IN WHAT ARE COMMONLY KNOWN AS RACK PULLEYS FOR WINDOW BLINDS
Year: 1885

page_text: COMPLETE SPECIFICATION.
I JOHN HUGHES of Hope Street, West Bromwich, in the County of Stafford,
Manager of Works, do hereby declare the nature of said invention for "IMPROVE-
MENTS IN WHAT ARE COMMONLY KNOWN AS RACK PULLEYS FOR WINDOW BLINDS"
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
My invention consists of the improvements hereinafter described in what are
commonly known as rack pulleys, which consists essentially of a coiled spring
carrying a roller or pulley at its top end, around which, the cord for raising or
lowering, a blind passes-By using a coiled spring, the necessary tension is auto-
matically given to the cord, by the yielding of the coils composing the spring, so
that the elasticity thus imparted, takes up any slack that may occur in the cord,
and always keeps the cord to the requisite winding tension.
I will now proceed to describe with reference to the accompanying Drawings
the manner in which my invention is to be performed.
Figure 1 is a front elevation of a pulley or self tightening expedient constructed
according to my invention, for giving the requisite tension to the raising and
lowering cord of a window blind.
Figure 2 is a side elevation of the same, and figure 3 is a transverse vertical
section of figure 1-In figure 4, the pulley carrying bracket is made from an
angular piece of metal instead of folded into a loop as in figure 1-Figure 5
represents a modification of figure 1-In this arrangement the spring is compressed
instead of being elongated-The view shews the spring under compression,
The same letters of reference indicate the same parts in the several figures of the
Drawing.
a is a coiled spring-a² is a loop or eye by which the pulley or cord tightening
expedient is attached to the side sash or stile of a window frame-b is a pulley
around which the cord c, figure 2 passes and d is a bracket carrying the said
pulley be is an axis upon which the pulley turns-The spring a is attached to
the bracket & by passing its upper end through a piercing and rivetting the end
of the wire marked a³, which securely connects the coiled spring to the bracket
carrying the pulley b.

page_text: The self tightening blind cord pulley always keeps the cord to which it is
connected in a perfect state of tension, for the proper winding of a blind; thus in
pulleys of the ordinary construction it is requisite to tighten more or less from
time to time the cord which may have stretched from wear or become distended
by change of temperature-This is never necessary in the blind pulley hereinbefore
described from the fact that it is self-regulating and self-adjusting and accom-
modates itself to all conditions to which it is or may be liable.
In figure 4 the pulley b is supported by an angle bracket instead of by a loop-
The principal is the same as in figure 1, other than its cheapness of production.
Instead of connecting or affixing the pulley by the loop a² by a loose screw, the
terminal end of the wire which forms the coil a may be turned at right angles
and wormed, so as to constitute a fixed screw as represented in figure 6, or the
part may be made into the form of a spike, which is driven into the side of a
window stile.
Figure 5 represents a modification of a pulley figure 1, the spring of which is
represented compressed-a is the coiled spring, b the pulley, c the cord, d the
abuttment and supporting bracket which is affixed to the window frame by
screws is a central rod which passes down the axis of the spring-The lower
end has a head f, which forms the lower abuttment for the said spring while the
upper end of the stem is surmounted by the pulley b so that the tension compresses
the spring instead of elongating it-By arranging the spring as described, there is
no possibility of the spring deteriorating by use.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
First A self tightening pulley for the cords of window blinds herein before
described and illustrated in figures 1, 2 and 3 of the accompanying Drawings,
consisting of a coiled spring a, a pulley b, turning upon a centre pin e and the
connecting loop a² made from the metal of the coil, also the modification
represented in figure 4 as described and set forth.
Secondly-A self adjusting or yielding pulley, for the cords of window blinds,
in which the coils of a spring are compressed, for giving the requisite tension to
the cord as described and set forth in figure 5 of the accompanying Drawing.
1
11 1007
JOHN
HUGHES.
By Henry Skerrett,
6, Livery Street, Birmingham,
Agent to the Applicant.