IMPROVEMENTS IN THE CONSTRUCTION OF SPRINGS FOR FIXING THE PULLIES OF WINDOW BLIND PRO, ALSO APPLICABLE TO OTHER PURPOSES
Year: 1873

page_text: LETTERS PATENT to William Davies, of Newhall Street, Birmingham,
in the County of Warwick, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF SPRINGS FOR FIXING THE PULLIES OF WINDOW BLIND
PROVISIONAL SPECIFICATION left by the said William Davies at the
Office of the Commissioners of Patents, with his Petition, on the
7th July 1873.
I, WILLIAM DAVIES, of Newhall Street, Birmingham, in the County
5 of Warwick, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF SPRINGS FOR FIXING THE PULLIES - OF
WINDOW BLIND CORDS, ALSO APPLICABLE TO OTHER PURPOSES," to be as follows:-
This Invention relates to the pullies round which are passed the cords
by which window blinds are raised or lowered in the methods well
O understood and practised. Such pullies as ordinarily made are carried
in a frame which slides in a grooved guide, having formed upon it a

page_text: .
rack consisting of angular teeth into which a spring presses which is
fixed to the back of the pulley frame, so that the cord can be tightened
by pressing the pulley frame and pulley in one direction, but is prevented
from moving back by the spring catching in the teeth of the rack.
My improvements consist of a novel shape and construction of spring
so that it is formed out of the same piece of metal which carries the
pulley. For this purpose I take a piece of sheet brass or other suitable
metal out of which I cut a disc having two radial arms projecting from
it opposite to one another. To the centre of the disc I attach a pin or
screw upon which the pulley revolves, and which also carries a knob or
handle by which adjustment of the pulley is effected. One of the arms
projecting from the disc is made sufficiently narrow at the part where it
joins the disc to fit and work between the sides of the groove in the
front of a rack frame as ordinarily constructed in the usual manner; its
extremity is then widened out so that when this broad end is bent over
until it lies parallel and opposite to the disc it may fit and work within
the rack frame described. The opposite arm is bent over in the same
way so that its extremity lies outside the other, and its point.is turned
out so as to engage with the teeth of the rack which is formed at the
back of the rack frame. The elasticity in the arm last described is
sufficient (aided by the elasticity of the inner arm) to enable it to serve
as a spring which passes over the teeth of the rack when the pulley
frame is moved to tighten the cords.
The construction and arrangement of spring described may be used for
other purposes where it is required to move a pulley or analogous article
in one direction only, and to retain it in the position into which it has
heen brought.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Davies in the Great Seal Patent Office
on the 7th January 1874.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of July, 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 William Davies, Her special licence that I,
the said William Davies, my executors, administrators, and assigns, or
such others as I, the said William Davies, 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, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF
SPRINGS FOR FIXING THE PULLIES OF WINDOW BLIND CORDS, ALSO APPLICABLE TO
OTHER PURPOSES," upon the condition (amongst others) that I, the said
William Davies, 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 William Davies, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement and accompanying Drawing (that is to say) :-
This Invention relates especially to the pullies round which are passed
for the purpose of keeping them stretched the endless cords ordinarily
used for the purpose of raising and lowering window blinds in the
methods well understood and practised. Such pullies as ordinarily made
and arranged are carried in a frame which slides in a grooved guide
attached to the side of the window frame or to any other suitable
support, and having formed upon it a rack consisting of angular teeth,
between which presses the point of a spring which is fixed to the back of
the pulley frame, so that the endless cord can be tightened when desired
by pressing the pulley frame and pulley in one direction, but is prevented
from moving in the other direction by the point of the spring catching
against the angular teeth of the rack.
My improvements consist of making the spring of a novel shape and
method of construction by which it acts as a guide to the pulley as well-

page_text: as a spring, and may be made out of the same piece of metal which forms
the pulley frame and carries the pulley. For this purpose I take a piece
of sheet brass or other sufficiently flexible and elastic metal out of which
I cut or punch a disc or rectangular piece, or piece of other suitable
shape (of any required size), having two radial arms projecting from it
opposite to one another. To the centre of the disc I attach a pin or
screw, upon which the pulley which carries the endless blind cord
revolves, and which also carries a knob or handle by which the adjust-
ment of the pulley and endless cord can be effected. One of the radial
arms projecting from the disc is made sufficiently narrow at the part
where it joins the disc to fit and work between the sides of the groove
formed in the front of a rack frame, as ordinarily constructed in the
usual manner; the extremity of this arm is then widened out so that
when this wide end is bent over until it lies parallel with and opposite to
the disc it may fit and work within the groove in the rack frame, as
described. The opposite radial arm which is also widened out at its end
is bent over in the same way so that its extremity lies outside the other,
and its point is bent or turned outward so as to engage with the angular
teeth of the rack frame, as already described. The elasticity of the arm
last described (aided by the elasticity of the inner arm) is sufficient to
enable it to act as a spring which passes over the angular teeth of the
rack when the pulley frame and pulley are moved so as to tighten the
endless cord round the latter, but by means of its point catching in
the angular teeth prevents the pulley frame and pulley from moving in
the opposite direction.
The rack frame and rack into which the spring works as described
may be made out of sheet metal, having its edges bent over so as to form
the edges of the groove within which the spring works, and having
angular teeth or projections formed upon its back by punching or other
suitable means; or it may be made of metal cast to the required shape
and having the angular teeth cast upon the back of the groove; or
sometimes I make the angular teeth upon a separate piece of metal
which fits into an opening made at the back of the frame which forms
the grooves, as already described, and I arrange such separate piece of
metal so that it is held firmly in its place by the frame when the latter
is screwed against the window frame or other support which carries it.
Sometimes instead of the arrangements described I attach the pulley
to a strip of metal or other suitable material, upon the back of which I

page_text: form the angular teeth (instead of upon the frame), and I make this
strip of metal fit into and work through a suitable frame which is
screwed to the window frame or other support, and inside which is fitted
a spring formed in a manner similar to that already described, excepting
only that the part which in the arrangement first described was formed as
a disc in that now described may be made rectangular or of any other
convenient shape (as it has not to support the pulley).
In the arrangement first described I prefer to form an open slot down
the centre of the strip of metal having the angular teeth formed upon it,
and a screw which fits and works through the outer part of the frame
passes through this slot, and when screwed down presses with its point
against the spring so as to disengage the latter from the angular teeth
when it is desired to slacken or remove the endless cord from the pulley.
The construction and different arrangements of the apparatus described
may be used for other purposes where it is required that a pulley or
other analogous article should be moveable in one direction only, and
should be retained in the position into which it has been brought.
The accompanying Drawing is in illustration of my Invention.
Figure 1 shews a piece of sheet metal punched out of a suitable shape
to form a spring according to my Invention; Figure 2 is an edge view
of the same; Figure 3 shews the same piece having the radial arms 6 and
c bent over and the pulley & supported upon the pin e which is rivetted
or fixed to the central part of the spring.
d
Figure 4 is a plan, Figure 5 a longitudinal section, and Figure 6 a
transverse section of a pulley frame for carrying the spring 9 and pulley
shewn in Figure 3. a is the rack formed of angular teeth punched up
in the bottom of the frame which is made of thin sheet metal; b, c, are
the sides of the frame, forming between their bent over edges a narrow
groove, within which the narrow parts of the spring work, the two ends
of the plate which form the spring being within the groove, and the
centre part which carries the pulley being outside the groove, as shewn
in Figure 5.
Figure 7 shews a longitudinal section, and Figures 8, 12, and 13
transverse sections of a different method of construction and arrangement
of the frame and rack for carrying the pulley and spring. In this

page_text: arrangement the frame a is cast in brass or other suitable metal, and has
an opening in the back into which fits from behind a separate plate 6,
upon which the angular teeth forming the rack are formed; the plate b
is made wider at the back or has projections fitting into corresponding
recesses in the frame a, so that when the latter is screwed against the 5
window frame or other support (as shewn in Figure 7), the plate b is
held firmly in its position; the spring c and pulley d are formed in the
method already described, and are fitted between the edges of the frame a
which forms a groove, between the edges of which the narrow parts of
the spring c slide, as already described.
Figures 9, 10, and 11 shew another arrangement of the spring and
pulley in which a plate, oval, or of other required shape, is used instead
of a knob or handle for the purpose of adjusting the pulley.
1
Figure 14 shews another of the arrangements which I sometimes
adopt, as above described. In this arrangement the angular teeth 1
forming the rack are formed at the back of the plate a, one end of which
is bent over so as to form a frame which supports the axle of the pulley b;
the plate a slides through the frame c which is screwed to the window
frame or other support (and is shewn in end view at Figure 15); this
frame c contains within it the spring d, which is made in the method 2
already described, but is entirely separate from and independent of the
rest of the apparatus; the spring d may be retained in its position by
the shoe or frame e within which it fits, and which has formed upon or
attached to it a stud fitting a hole at the back of the spring which is
thus prevented from moving. The plate a is shewn with a longitudinal 2
slot down its centre (in Figure 16) through which the screw f passes,
the point of which can be pressed against the spring 9 when required for
the purpose of releasing the latter from the rack when it is required to
adjust or withdraw the plate a and pulley b.
Having now described my Invention and the mannon in which it is

page_text: Also the general construction and arrangement of the apparatus, sub-
stantially as described and shewn in the Drawing.
In witness whereof, I, the said William Davies, have hereunto set
my hand and seal, this Third day of January, in the year of
our Lord One thousand eight hundred and seventy-four..
Witness,
A. JOHNSON,
Patent Agent,
11, Cherry Street,
Birmingham.
WILLIAM DAVIES. (L.S.)