IMPROVEMENTS IN RACK PULLEYS
Year: 1885

page_text: We EDWARD VERNON BAILEY and CHARLES MACKEY both of Great Hampton
Row, Birmingham, in the County of Warwick, Brass Founders, and NEHEMIAH
BROUGH of Potters Hill, Aston Juxta Birmingham aforesaid Tool Maker do
hereby declare the nature of said invention for "IMPROVEMENTS IN RACK
PULLEYS and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
"
Our invention consists in constructing what are commonly known as rack
pulleys for tightening and holding the cords of window blinds, which is effected in
a simple and efficient manner without employing rack teeth as is commonly
employed in pulleys of the ordinary construction.
Our said invention consists of a plain strip of metal slightly bent at its ends, so
as to raise the said strip out of the plain of the attachment parts or ears-The
pulley around which the cord passes is attached to and moves with a slide-This
slide is fixed in any desired position by an excentric boss or lever which grips the
edge of the frame, and so holds and fixes it in position, the pulley constructed
according to our invention is simple in its construction, efficient in its action and
cheaply made.
We will now proceed to describe with reference to the accompanying Drawings
the manner in which our invention is to be carried into effect.
Figure 1 is a rackless pulley constructed according to our invention for holding
and supporting the cords of window blinds, the slide carrying the pulley being
shewn fixed in position-Figure 2 is a longitudinal vertical section of the slide
figure 1, so as to better exhibit the grip of the excentric upon the edge of the
frame. Figure 3 shows the grip raised and out of action. When in this position
the slide carrying the pulley is free to move up or down upon the slide. Figure 4
is an end elevation of figure 1, while figure 5 is a cross section on the dotted
lines A B figure 1. In figure 6 the grip is slightly modified by interposing
between the gap like boss and the edge of the frame a bearing or contact strip or
piece which increases the frictional contact of the bearing surfaces. Figure 7 is a
modification of the arrangement last described. In this case the frame is capable
of sliding up or down, instead of being fixed, which is held by the cam grip before
described and figure 8 is an edge view.
In figure 9 the binding or grip is effected upon the flat of the frame instead of
upon the edge.
The coma Inttron
1

page_text: a is a plain frame which is affixed in position by the ends a a² which are bent
out of the plane of the other part, so as to raise the strip for the moving freely of
the slide b. c is the pulley attached to and carried by the slide. d is an excentric
or lever boss which grips the edge a³ of the frame a, and d is the lever which
actuates the excentric.
In order to adjust the slide to its proper position, upon the supporting frame a
for tightening the cord e, it is only necessary to turn the excentric d, by its
lever upon its fulcrum d³ into the position represented in figure 3 so as to
remove the grip of the excentric from the edge of the frame a³ ³, when the slide b
can be lowered and the requisite amount of tension put upon the cord, for properly
winding the blind. When in this position the lever is depressed, bringing the
excentric or enlarged part of the boss d forcibly in contact with the edge a³, and sɔ
forcibly holding the parts in position as represented in figure 1, so that in order to
adjust the slide carrying the pulley, it is only necessary to raise the lever of the
grip can, when the parts are liberated and the slide removed to any desired
position.
In figure 6 a supplementary binding plate is placed between the edge of the
frame and the grip of the cam. f is the frame, g is the friction plate, h is the cam
or excentric, and i is the slide. To fix the pulley in position, depress the lever,
when the enlarged part of the excentric forcibly presses the gripping plate against
the edge of the frame, thereby holding the slide (carrying the pulley) in position.
Figure 7 is a modification, the strip or frame in this case carries the pulley and
is capable of adjustment by sliding within a holder, the frame carrying the pulley
is affixed as before by the excentric or cam. a is the movable frame and c is the
pulley. d is the excentric and b is the fixed holder. In figure 9 the bite of the
a is
cam acts upon the face of the strip instead of at the edge as before described.
the frame, bis the movable slide, d is the thick part of the cam, and is the thin
part, the grip is obtained between the inside of the frame b and the face of the
strip a.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is
First. The improvements in what are commonly known as rack pulleys for
tightening and holding the cords of window blinds, consisting of a plain or
unnotched frame, upon which a slide carrying the pulley works; the said slide
and pulley being held in position by a grip like cam or excentric, the parts being
arranged and acting in the way, and for the purpose as described and set forth in
figures 1, 2, 3, 4. 5 and 6 of the accompanying Drawings; also the modification
marked figure 6 for presenting a larger gripping surface to the edge of the frame.
Secondly. The modifications described and set forth in figures 7, 8 and 9 of the
accompanying Drawings.
I
0.
EDWARD VERNON BAILEY.
CHARLES
MACKEY.
NEHEMIAH BROUGH.
By Henry Skerrett,
6, Livery Street, Birmingham,
Agent to the Applicants.