Improvements in Rack Pulleys for Window Blind, Curtain, and other Cords.
Year: 1896

page_text: Date of Application, 30th Oct., 1906
Complete Specification Left. 10th June, 1897-Accepted 10th July, 1897
Complete Specification Left. 10th June. 1897-Accepted. 10th July 1897
PROVISIONAL SPECIFICATION.
Improvements in Rack Pulleys for Window Blind, Curtain, and other
Cords.
SAMUEL PHILLIPS, Eland House Glanmor Place, Llanelly Manager of
Chemical Works, THOMAS JONES, Bres House, Llanelly, Mining Engineer and
Surveyor, do hereby declare the nature of this invention to be as follows:-
Our invention consists in the application and attachment of a spiral spring, or
springs, to rack and other pulleys; which will be self-adjusting, and maintain
constant and even tension on the cord or cords.
For the purpose of our invention a spiral spring which is attached at its respective
ends to washers is fitted on a pillar between the pulley block and a screw nut.
This nut by being screwed in the one direction or the other acts as an adjuster of
the spring. The spring has a tendency to push the pulley block to the full limit
allowed by the blind cord which passes round the pulley and therefore a constant
and uniform tension on the cord is maintained.
1000
SAMUEL PHILLIPS.
THOMAS JONES.
COMPLETE SPECIFICATION.
Improvements in Rack Pulleys for Window Blind, Curtain and other
Cords.
We, SAMUEL PHILLIPS now of 9 Mina Street (formerly of Eland House, Glanmor
Place), Llanelly, Manager of Chemical Works, and THOMAS JONES, of Brès House,
Llanelly, Mining Engineer and Surveyor, do hereby declare the nature of this
invention 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 the application and attachment of a spring or springs
to rack and other pulleys, which will be self-adjusting and maintain a constant
and even tension on the cord or cords.
For the purpose of our invention a spiral spring which is preferably attached
at its respective ends to washers is fitted on a pillar between the pulley block and
a screw nut, this nut by being screwed in the one direction or the other acts as an
adjuster of the spring. The spring has a tendency to push the pulley block to the
full limit allowed by the blind cord which passes round the pulley and therefore a
constant and uniform tension on the cord is maintained.
Referring to the accompanying drawings:-Figures 1 and 2 are respectively a
Price d

page_text: front elevation and a side elevation of one form of construction of rack pulley
according to this invention suitable for use in connection with a roller blind. The
endless cord A for operating the blind passes at its upper end around the usual
blind roller-pulley B and at its lower end around a pulley C¹ mounted on the
pulley block C which is adapted to slide along the (preferably square) pillar D.
This pillar D is fixed at its ends in projecting parts ee of a support or bracket E
which is intended to be attached to the window frame (not shown) by means of
screws at ff. The pulley block C is formed with a square hole in which the square
pillar D fits freely in such a manner as to allow of the pulley block sliding freely
along the pillar whilst preventing any twisting of the pulley block. The blind
cord is kept stretched with a constant and uniform tension by means of the spiral
spring which encircles the pillar 1) and bears at its lower end through the
medium of a washer G (to which it is preferably attached) against the pulley
block C. The upper end of the spiral spring F bears similarly through the medium
of a washer G¹ (to which.it is preferably attached) against a nut H which works
on the screw threaded edges of the pillar D).
The spiral spring F has a constant tendency to force the pulley block C to the
utmost limit allowed by the blind cord A and thus to maintain a constant and
uniform tension on the blind cord.
If the blind cord tends to become slack owing to variations in the weather or
to other causes, the slack is avoided by means of the pressure of the spring F up
to the limits of the action of the latter. The force exerted by the spring F may be
adjusted within certain limits by screwing the nut H along the pillar as required.
For the purpose of taking up an amount of slack in the blind cord which is
beyond the range of the action of the spring, the nut H is screwed along the pillar
so as to move the pulley block C together with the spring F along the pillar D
until the slack has been taken up and the spring is compressed to the extent
sufficient to produce the desired tension of the blind cord.
In the arrangement shown in front and side elevation in Figures 3 and 4
respectively the positions of the pulley block and the nut are the reverse of those
in the preceding arrangement. The washer next to the pulley block is dispensed
with and in lieu thereof the pulley block C is formed with a projecting plate e to
which is fastened one end of the spiral spring F the other end of which is fastened
to a similar projecting plate g on the washer G¹ next to the nut H.
The nut H engages by means of a collar H¹ with the washer G¹ in such a manner
that when the nut is turned in one or the other direction the washer G' will not
turn but will be drawn or pushed along the pillar D whereby the spiral spring F
is lengthened or shortened so as to exert an increased or a diminished pull upon the
pulley block C and the blind cord A as desired.
In the arrangement illustrated in side elevation in Figure 5, the pulley block C
is formed with two lugs c¹ and in which are square holes through which the
square pillar D passes. The bracket E is formed with a central projecting part e¹
in addition to those (c) at its ends for holding the pillar D. A spiral spring F
encircling the pillar is arranged to bear against the top lug c of the pulley block,
and a similar spring F³ is arranged to bear against the bottom lug of the pulley
block. These springs F, F3 are capable of adjustment respectively by means of
a nut H³ and washer G2, and a nut H³, and washer G3 working on the screw-threaded
pillar.
In the arrangement illustrated in side elevation in Figure 6 the pulley block C
works direct on the pillar D as in the arrangement shown in Figures 1 and 2.
The spring F is fixed at top and bottom to washers G, G5 bearing against an
adjusting nut H and the pulley block C respectively. The nut H and the pulley
block C are each formed with inwardly inclined claws h and c which take over
and engage with the correspondingly bevelled edges of the washers G and G5
as shown.
By these means whilst the action of the spring can be adjusted by the screw
nut H', the whole device will work equally well in an inverted position.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
1. In a rack pulley for window blind, curtain and other cords, a spiral spring
acting upon the sliding pulley block in combination with an adjusting nut
screwing upon the pillar substantially as hereinbefore described and for the purpose
specified.
2. The improved rack pulley constructed, arranged and operating substantially
as herein before described with particular reference to Figures 1 and 2 of the
accompanying drawings.
3. The improved rack pulley constructed, arranged and operating substantially
as hereinbefore described with particular reference to Figures 3 and 4 of the
accompanying drawings.
4. The improved rack pulley constructed, arranged and operating substantially
as hereinbefore described with particular reference to Figure 5 of the accompanying
drawings.
5. The improved rack pulley constructed, arranged and operating substantially
as hereinbefore described with particular reference to Figure 6 of the accompanying
drawings.
1007
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.