IMPROVEMENTS IN APPARATUS FOR CHECKING CORDS OF BLINDS AND OTHER LIKE ARTICLES REQUIRED TO BE PULLED UP AND LET DOWN
Year: 1882

page_text: LETTERS PATENT to Andrew Dix and Thomas Henry Dix both of Rock
Ferry in the County of Chester for an Invention of "IMPROVEMENTS IN
APPARATUS FOR CHECKING CORDS OF BLINDS AND OTHER LIKE ARTICLES
REQUIRED TO BE PULLED UP AND LET DOWN
PROVISIONAL SPECIFICATION left by the said Andrew Dix and Thomas
Henry Dix at the Office of the Commissioners of Patents on the 20th July
1882.
ANDREW DIX and THOMAS HENRY DIX both of Rock Ferry in the county of
Chester "IMPROVEMENTS IN APPARATUS FOR CHECKING CORDS OF BLINDS AND
OTHER LIKE ARTICLES REQUIRED TO BE PULLED UP AND LET DOWN
"
This invention has for its object a checking apparatus of very simple character
that will work perfectly with a single cord.
It consists essentially in a pivoted cam or its equivalent which can be pressed
back by the cord so as not to interfere with it when the cord is held a little out of
the perpendicular but will by its own weight and the friction of the cord fly into
place and jam the cord, when the latter is let go and allowed to hang vertically
with the weight of the blind over the pulley tending to draw it upward. At the
same time a downward pull will instantly free the cord by pulling the cam out of
bight when if the cord be held obliquely toward the side where the cam is, it will
glide past the cam in an upward direction without jamming. There are various
ways of carrying this out for instance:-Immediately below the top bar of a
Venetian blind a small bracket with two cams one for each string can be placed
and the strings made to pass through a slot in the bracket between a metallic face
and the cam face. Or instead of this the cord could pass through the eye of a
lever when on being pressed to one side and pulled it will lower the lever and
thus bring a cam above the top lath out of bight and so liberate the cord. The
moment however the cord by being held vertical liberates the lever the cam comes
into bight again.
In a roller blind the cam is preferably placed in a bracket a little below the
pulley of the blind and works in the same way as that already described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Andrew Dix and Thomas Henry Dix in the Great Seal Patent
Office on the 20th January 1883..
ANDREW DIX and THOMAS HENRY DIX both of Rock Ferry in the county of
Chester "IMPROVEMENTS IN APPARATUS FOR CHECKING CORDS OF BLINDS AND
OTHER LIKE ARTICLES REQUIRED TO BE PULLED UP AND LET DOWN "
This invention has for its object a checking apparatus of very simple character
that will work perfectly with a single cord, that is that will not require a second
cord attachment to release the catch.
It consists essentially in a pivoted cam or its equivalent which can be pressed
back by the cord so as not to interfere with it when the cord is held a little
out of the perpendicular but will by. its own weight and the friction of the cord
return into such a position as to jam and retain the cord, when the latter is let go
and allowed to hang vertically with the weight of the blind over the pulley
tending to draw it upward, at the same time a downward pull will instantly
free the cord by pulling the cam 'out of bight when if the cord be held obliquely
toward the side where the cam is, it will slide over the cam in an upward
direction preventing the cam returning to the position in which it would act
upon the cord to retain it.
Referring to the drawings
Figs 1. and 2. show our invention adapted for use with Venetian blinds
Under the top bar A, of a Venetian blind a small bracket B, with two or more
cams C, one for each string D is placed.
The strings or cords D pass over pulleys or rollers on the top of the lath in the
usual way and pass down between the cam C and the side 6 of the bracket B.
When the cord is pulled down the friction on the cam forces it' backward at its
bottom edge and releases its hold on the cord. When the cord is slackened and
the weight of the blind pulls it up, the bottom edge of the cam C by its own
weight falls against the cord and the friction of the cord then upon it tends to
force it upward and against the side B and thus retain the cord. By holding the
cord outward in an oblique direction as shown in dotted lines so that the cam
cannot return to the position at which it would grip the cord between its lower
edge and the side of the bracket the cord will be allowed to pass freely upward,
but on being completely released or brought again to the perpendicular the cam
will assume the position to retain it. No second cord or its equivalent are at any
time required to release the cam or prevent its gripping the cord D. The face of
the cam C which bears, against the cord D may be made rough or corrugated if
desired to increase the friction.
In Figs 3 and 4 the same invention is shown adapted for use with roller blinds.
Like letters refer to like parts. The action is precisely similar to that already
described. The cord D being attached to and wound upon the bracket E at the
end of the roller passes down between the cam C and the side b of the bracket B¹
in which it is fixed. When the blind is to be lowered the cord D is held obliquely
from the bracket against the face and bottom edge of the cam C and allowed to
pass gently upward. When the blind is to be raised the cord is pulled downward
and on the strain being taken off it the cam falls against it and by the friction
of the cord upon it retains the cord in the position at which it was placed.
The Bracket B₁ may be placed as shown in the drawings or in any desired
position on the side of the window frame.
F is a pin on which the cam is pivoted and G another pin placed in the top of
the bracket to prevent the bottom edge of the cam rising too high or tumbling
over.

page_text: Instead of the method described which we prefer as being the simpler the cord
may be passed through the eye of a lever, on being pressed to one side and pulled
it will lower the lever and thus bring a cam above the top lath out of bight and so
liberate the cord. The moment however the cord by being held vertical liberates
the lever, the cam comes into bight again.
Having now described our invention and the best modes known to us of carrying
it into effect we wish it to be understood that we are aware that eccentrics and
other devices such as tubes working on pivots have been used to hold or retain the
cords of blinds or other articles in any desired position, and that we do not make a
general claim for checking the cords by wedging, but that what we believe to be
new, and desire to protect is.
First The construction of apparatus for checking or retaining the cords of blinds.
and other articles with a pivoted cam so placed as to allow the cord to pass in an
upward direction when the cord is pressed obliquely against its face and by its own
weight and the friction of the cord, check or jam the cord against the side of the
apparatus when passing vertically upward substantially as and for the purposes
described and shown.
Second The construction of apparatus for checking the cords of blinds or other
articles in which a pivoted cam acting against the side of a fixed bracket checks or
retains the cord when it is passing in a vertical upward direction but which allows
the cord to slide upward past it when held obliquely against its face substantially
as described and shown.
In witness whereof we the said Andrew Dix and Thomas Henry Dix have
hereunto set our hands and seals this nineteenth day of January in the year
of our Lord one thousand eight hundred and eighty three.