Improvements in the Mechanism of Window Blind Furniture.
Year: 1890

page_text: Date of Application, 19th June, 1890
Complete Specification Left, 25th Feb., 1891-Accepted, 19th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Mechanism of Window Blind Furniture.
I ROBERT SCOTT BURN of Oak Lea Edgeley Road near Stockport Cheshire
Member of the Institution of Mechanical Engineers do hereby declare the nature
of this invention to be as follows:-
My improvements in the mechanical contrivances used in adjusting and controlling
the working of ordinary window blinds in use and which are generally, made of
calico have for their object two classes of mechanical adjustments-first the
adjusting to any degree of accuracy required the tightness of the cord which winds
or unwinds the window blind upon or from its roller-and this by the application
of a movement of which an external and an internal screw constitute the chief
feature second, the adjustment of the position of the window blind at any point
desired in its rise and fall by the employment of mechanical self acting contrivances
in one of which the chief feature is the employment of a cam and helical spring
movement in the other the employment of a finger button or knob controlled by a
helical spring movement-full details of all of which improvements will be found
described and illustrated in the following Specification and its accompanying sheet
of drawings.
The mechanical appliance or contrivance by which window blinds are drawn or
raised up and lowered as desired in which the main features are a pulley round
which the raising and lowering cord takes a half lap and the rack and spring by
which the position of the central stud of the pulley or its distance vertically from
the centre of the roller round which the blind is wrapped or from which it is
unwrapped is adjusted and the cord tightened or slackened accordingly is well
known and so largely employed and this perhaps so from the comparative cheapness
of the appliance that it may be said to dominate over all other forms of window
blind furniture.
This form of appliance has however many disadvantages. It is apt rapidly to
get out of order and there is from the very nature of the rack with its notches,
catches or indentations placed at certain intervals and equidistantly from each
other a difficulty-inherent in the device-to give the exact amount or degree of
adjustment to the pulley, so that the tightness of the cord is precisely that which is
required for the proper working of the window blind. The cord may be too tight
while the spring catch or detent of the pulley carriage engages with one particular
notch or catch of the rack; while the cord will be far too slack if the spring catch
or detent of the pulley carriage is placed in the notch of the rack next in succession
and immediately above it. The position of the detent if placed mid-way between
these two notches of the rack would be that which would give the precisely correct
amount of tightness of the window blind cord. But this desired position is just that
which cannot be obtained inasmuch as there is no notch at that point by which to
keep the detent of pulley carriage in place. Another disadvantage which this
particular form of window blind appliance contrivance possesses is the difficulty
which is too frequently met with, of giving any desired adjustment to the pulley
carriage, and this from the strength or dexterity required to plan the pulley carriage
in the position desired to give the window blind cord the exact degree of tightness
necessary difficulty not lessened by the unworkmanlike way in which the
contrivance is but too often made as by the leaving of sharp corners which are but
too well adapted to act as weapons inflicting as they are too often found to inflict
wounds which if not so painful are at least disfiguring to the hands of those who
have been attempting the desired adjustment of the pulley carriage to the rack, an
attempt not always successful.

page_text: These disadvantages or defects present in what may be called the normal form
of window blind furniture, has given rise to various attempts to introduce a
mechanical contrivance by which these defects could be remedied and an apparatus
obtained not only thoroughly efficient but one easily worked even by those ignorant
of mechanical adjustments. Those improved contrivances in window blind furniture
however ingenious and effective and really efficient are generally so complicated
more or less that they are of necessity much more expensive than the normal
form of appliance already described, while some of those are somewhat apt to get
out of order, involving time and money in their repair or readjustment. The
contrivances now in this Specification to be described and which are illustrated
in its accompanying sheet of drawings are attempts to introduce methods of
raising and lowering of window blinds-not of the class known as "Venetian
which while efficient in operation and not liable to get out of working order are
readily and easily adjusted even by those least acquainted with mechanical
contrivances and their adjustments.
""
The first contrivance to be described is illustrated in Figs. 16, 13 and 21 these
being drawn full size or to natural scale. In this contrivance the screw is the
leading mechanical feature. The pulley a a Fig. 16 round which the window blind
cord takes a half lap-the upper lap of the cord taking on to or engaging with
the pulley of the window blind roller above-has its spindle carried by the forked
or split head d d of the adjustable carrier d d e ee, the lower part or stem of
which e e e e is made tubular or hollow the hollow part being tapped or screwed
with a fine pitched screw. This tube square or hexagonal in section on the exterior
passes through the central eye of the upper steadying stud or small bracket
which forms part of and projects from the attaching plate h, which is screwed to
the window frame part of which is shown at iii as shown in sectional elevation in
Fig. 16. The adjusting screw which is carried by the lower steadying eye or
bracket m n of the attaching plate his screwed with a screw of the same pitch
at its upper end as the pitch of the screwed interior of the tubular stem e e e e of
the pulley (a a) carrying part d d, while the lower end off is provided with a
finger and then button n n firmly secured with a pin; the edge or rim of the
button may be milled the whole contrivance is made of brass, the only exception
to this may be the button n which if preferred can be made of white porcelain
with central side plate of brass. When the appliance or apparatus is fixed in place
the attaching plate being secured to window frame at a point low enough
for convenience of working. The upper or pulley a a carrying part d dee is fixed
in the position as shown in the drawing, the upper end of adjusting screw being
engaged with the internal screw of the tubular part e e e e some one fourth of an inch
or so. The window blind cord is then passed over the two pulleys the pulley a a
of the adjusting contrivance, shown in drawing Fig. 16 and the pulley of window
blind roller, and then the ends are to be sewn or otherwise firmly secured together.
As it is not an easy thing to adjust and fasten the ends of the cord so that it will
embrace both pulleys to the degree of tightness necessary to work the blind easily
and with certainty in its movement, the end when first adjusted will probably be too
slack. Very frequently this is the normal or usual case with ordinary window
blinds of calico or other flexible material. In this case then in order to tighten the
cord it is only necessary to turn the button nu from left to right when as it engages
with the internal screw of tubular part e e e e, it will cause this part to descend in
the direction of the arrow o thus causing the pulley a a hung on its spindle to
descend also thus tightening the cord b. As the cord as made of the usual
materials is liable to be effected by the weather, a window blind adjusted so as to
be properly worked, may on the coming of wet or damp weather leave its cord so
tightened by the damp or moist condition of the air or atmosphere that it will be
difficult to work the window blind readily, the cord thus acting as being a simple
yet in its way as a suggestive hygrometer. In this case the button nn Fig. 16 in
accompanying sheet of drawings is turned from right to left when the screwed stem
or stud so engages with the internal screw f of part ee that it causes it and its

page_text: carried pulley a a to ascend in the direction of the arrow p. It is obvious that by
the contrivance as here described the nicest degree of accurate adjustment of the
pulley a a carrying the window blind cord bb may be secured by turning the
button n n either to the right or to the left as desired. In adjusting the apparatus
the screwed stem ff may pass through a simple aperture in the centre or eye of the
bracket m m; but in this case should the button n n be turned too much in one
direction it may be disengaged or set free from the screwed part of the tubular
part e e e e; and the stem would then be free to drop out of the eye of the
bracket m m, which the part e e e e to be pulled out of the eye of the bracket 99
thus for the time disorganizing the apparatus.
In
To prevent this disarrangement of the parts; the foot of the screwed stem ff
Fig. 16 may be provided with a collar or ruff as at a Fig. 13; the underside of
which rests and works against the upper face of the end or eye of bracket m, n;
the tail or lower termination of the screwed stem ff passing through the eye of
the bracket in m and revolving freely therein, and finished off with the button or
finger and thumb holder n, n which is pinned or firmly secured thereto.
Fig. 17 we give a cross section on the line 12 of Fig. 16 and in Fig. 18
a plan of top of pulley carriage as seen in looking down upon top in the
direction of arrow in Fig. 16. Figs. 13 and 21 in accompanying sheet of
drawings illustrate two forms or modifications of that illustrated in Fig. 16, but in
both of which the same principle of operation is followed. In Fig. 13 which is a
vertical section of the appliance or apparatus as fixed to the window frame bb by
the plate cc and bracket dd. The button ee milled or roughened on its outer edge
or periphery by which the adjusting screw is turned or made to revolve on its
axis as desired, works within a guard gg, formed at the foot or lower termination
of the casing or cylinder ii within which the adjusting screw is enclosed, and the
lower part of the pulley carrying parth works or slides up and down as it is raised
or lowered accordingly to the direction in which the button ee with its connected
adjusting screw is turned.
The guard is not carried completely round, but extends only part way as
shown in side view of lower part of Fig. 13 in Fig. 15, showing width g' of
guard.
h
This enables part of the button to be exposed to the sides as at e¹ e¹ in Fig. 15
so that it can be readily got hold of by the fingers when working the apparatus.
The casing or cylinder ii is in the modification of Fig. 16 here illustrated not
made circular but hexagonal in section as shown in Fig. 14 which is a horizontal
cross section of Fig. 13 taken on the line 1, 2, Fig. 13. The drawing in Fig. 13
shows the apparatus adjusted at such a point, that the pulley carrying part has
been pulled down by the action of the screw worked by the button ee to its
lowest point of descent, in which the lower part of the head of rests upon the
upper edge of the outer casing, barrel, or cylinder i i. In Figure 21 I illustrate
in vertical section drawn as are all the other subjects on the sheet of accompanying
drawings to natural scale or full size, another modification of the same principle
of arranging the chief relative parts of and working the window blind apparatus
as I have illustrated in, and have hereinbefore described in connection with
Fig. 16 aforesaid, the apparatus illustrated in Fig. 21 the chief or principle parts
are the same in the construction and the arrangement only being in some respects
similar, the similar letters to those referring to certain parts in Fig. 13 referring to
similar parts in Fig. 21. In this the guard gg partially covering the button is
somewhat differently constituted from similar part 7 in Fig. 13 the button being
however partly exposed as shown at e' e in side view Fig. 23, g'g showing width
of the guard at side.
propose
is
The other mechanical contrivance in window blind furniture which I
the arrangement of parts by which the ordinary or what may be called the old
fashioned system of raising and lowering the blind is effected by operating upon
an endless cord stretched round two pulleys and for which the contrivance hercin
before described and illustrated in Figs. 16, 13, and 21 in accompanying sheet of

page_text: "
drawings is done away with and the blind raised or lowered by using or operating
with an open cord loose at one end and connected at the other and upper end with
the pulley of the window blind. The contrivance now to be described and
illustrated in Figs. 4, 5, 6, 7, 8 and 9 in accompanying sheet of drawings, is based
upon an appliance which as it is much used in Belgium I for the purposes of this
Specification propose to designate the Belgian. Of this the following brief
description while explaining its advantages on the score of simplicity and
consequent cheapness of make, the readiness with which it can be fitted up and
worked, will also show its disadvantages. After this explanation is given shall
then proceed to describe and illustrate the improvements which I have made on
the "Belgian system of window blind furniture by which its disadvantages can
be got rid of, and it can be made an effective, easily worked, and cheaply made
apparatus for raising window blinds of the ordinary kind made of a pliable fabric
such as calico. The "Belgian system may be here described by the aid of the
drawings in Figs. 1, 2, and 3 in accompanying sheet of drawings which it is to be
understood are not to be taken as drawings but merely as diagrams serving to
make clear the character of the system. To one end of the window blind roller
part of which is shown at side elevation in Fig. 2 at a a, a pulley made cheaply
of tin with deep side flanges cccc is fixed securely. The outer flange of pulley
carries at its centre an arbor or stud dd which serves as the axis or spindle on
which the window blind roller revolves in its bearing fixed to the window side
framing. Round the pulley bb a cord eee Fig. 1 is wound being at the end firmly
secured to the pulley of the window blind roller the end of window blind
represented by the line ff Fig. 1 is fixed. When the roller is put in place the
blind is wrapped by hand round the roller with the side or sheet of the blind
nearest the window until the full length of blind is taken up by the roller and its
lower edge as y close to the roller. The lower edge y of blind is finished with a
looped part into which a rod or bar is placed to act as a weight tending to pull the
window blind down and cause it when free to move to unwind itself from the
roller. Supposing the blind roller is free to move on its axis as at d Fig. 2,
the weight of the rod or bar in the loop g Fig. 1 causes the blind to fall in the
direction of the arrow i, and as it falls the consequent revolution of the roller a a
winds the cord ee Fig. 1 round the tin pulley in the direction of the arrow kk
Fig. 1 until there is a length of cord wrapped round the tin pulley bb equal to the
full length of drop of window blind ff Fig. 1 from top to bottom of its fall.
now when the window blind is at the lowest point of its drop, the cord ee is pulled
in the direction of the arrow mm Fig. 1 it is gradually unwound from the
pulley bbcc and as this causes the window blind roller to which it is secured to
revolve, its revolution from left to right causes the blind f Fig. 1 to be wrapped
round the roller a a. If the cord ee was freed from the control of the hand, the
weight or loop g of blind ff would cause the blind to drop suddenly quickly re-
winding the cord on to the pulley.
If
A contrivance then is obviously required to be applied to the apparatus above
described by which the ascent and descent of the window blind can be controlled
and arrested or put in motion as desired. This is met with in another part of the
Belgian system illustrated in the diagram Fig. 3 in which ab is a cam-shaped
body working upon a central stud or pin.c which is a little eccentric to the true
centre of the semi-circular end a. The cam shaped part ab is jointed by the pin c
between two jaws or plates one of which is shown at d which project from and
form part of the back plate secured firmly by two screws one at each end to the
window frame as shown. The centre stud or joint pin c is so placed in relation to
the cam ab, and the back plate ee, that a space is left free or open to admit of the
window blind cord ff-corresponding to cord ee in Fig. 1-being passed through-
which cord is fixed at any point of its length-correspondingly fixing the window
blind as in Fig. 1 at the desired height by pressing in the end of the
handle of the cam ab so that it moves downward and inward in direction of
arrow i, its under side presses upon and jams up so to say the cord ff between its
C

page_text: edge and the face of the back holding plate ee. And in order to give the inner
edge of the cam ab a better grip of the cord its inner edge is roughened or made
saw edged.
Fig. 12 illustrates the position which the cam ab assumes when the cord is
held tightly between its inner edge and the face of plate e e.
When it is desired
to drop the window blind fƒg Fig. 1 the cord ff Fig. 12 is released by raising in the
direction of arrow i the end of the handle g h of cam a b and bringing the cam to or
towards the position as shown in Fig. 3.
If it be desired to raise the window blind the end g of the handle gh of the
cam a bis raised by one hand in direction of arrow i and the cord taken hold of
by the other hand is pulled downwards vertically or in the curved direction as
indicated by dotted lines and arrow m, and on the window biind reaching the point
desired, the end g of handle g of cam a b is pressed inwards in direction of
arrow, and the cord ff being gripped between its edge and face of plate e e is held
fast as hereinbefore explained.
Efficient up to a certain point as this window blind furniture as now described is,
it has this great disadvantage, namely that to work it with certainty and precision
it is necessary to employ both hands. For supposing that it is desired to drop the
blind gently, if the cam ab be raised in direction of arrow m should the cord be
left free to move in place of being held on the other hand, the weight of the window
blind itself and of its cross bar g Fig. 1 will cause it to drop suddenly striking
the window sill violently and likely throwing the cord off the blind roller pulley bl
cc Fig. 2 and which it will take some time to replace. If on the contrary it is
desired to raise the window blind, this can be easily enough done by taking hold
of the cord and pulling it outward and upward in direction of arrow m Fig. 12 this
will lift the cam in direction of arrow i, and the grip of the cam ab on the cord f
being released, the cord may be pulled outwards sufficiently to raise the window
blind to the point desired. But if the cord was then released it being free from the
grip of the cam a b, the weight of the window blind itself and its cross bar would.
cause it to drop suddenly in place of being raised. Now it is not always easy to
approach closely to a window in order to use two hands to work the apparatus I
have described, flower stands, worktables, and the like being frequently placed in
front of the window.
In order therefore to make the appliance which I have designated the "Belgian"
system of window blind furniture, self acting and self adjusting in so far that it
may be worked by means of one hand only.
have adopted improvements to it now to be described aud as illustrated in
Fig. 20 on the accompanying sheets of drawings. The principal feature of the
improved apparatus or appliance is much the same as the diagram Fig. 3 namely
a cam shaped part a b c as shown in Fig. 20 which is a side elevation of one form of
my improved apparatus. But in order to keep the grip of the union serrated edge
or of the cam a b c always in action unless when it is acted upon by the cord d d in
the hand of the party using the apparatus, I extend the snugs or jams one of which
is shown at e e corresponding to d in Figs. 3 and 12 so that it can carry a. helical
spring, the inner end of which takes into a depression made in the outer face gy
of cam the outer end being secured by a pin to the jams e e. The spring is
strong enough to keep the cam a be pressed inwards normally upon the cord dd
retaining it in any position required. But by manipulating the cord by one hand
only as by raising it and pulling it as shown in direction of dotted lines the grip
of the cam abc upon the cord dd will be released and the blind raised or lowered
as desired. By letting go the cord d d from the hand the spring resumes its
action and forces the cam a b c downwards in direction of arrow and completes
its grip upon the cord d. In this contrivance the handle yh as in the Belgian form
of the cam illustrated in Figs. 3 and 12 is dispensed with and the outer end formed
as in Fig. 20. This curved end could still however be used as a handle to raise the
cam abc from out of action on the cord d, the cam being manipulated in this case
so that the spring will prevent the cord moving outwards from the cam too rapidly

page_text: and the window blind as ff Fig. 1 dropping too suddenly. In place of having the
springFig. 20 so placed in relation to the cam be that it presses on its upper
edge pushing the cam outer end downwards it may be placed so that acting on the
inner or lower edge of the cam it will pull this downward and inward in the direction
of the arrow, the spring being so adjusted to the cam at its outer and upper end,
and to the plate m, m at its lower or inner end in such a way as to allow the cord d d
to drop as before explained.
C
In place of the contrivance just described and illustrated in Fig. 20, by which
the adjustment of the cam a b c is made self acting by means of a helical spring, the
contrivance illustrated in Figs. 7 8 9 and 10 may be used. In this the apparatus
assumes the form of a hemi-spherical button a a Fig. 7 connected with and attached
by a helical spring to the holding on plate cc by which the contrivance is
secured to any convenient part of the window frame. The central part of the
plate ce is provided with a projecting cylindrical study the outer and free end of
which is hollowed out so as to embrace the window blind roller cord e-corre-
sponding to Fig. 12 or d d Fig. 20-when this is pressed up against the end of
stud by the button a a pressing inwards through the action of the helical spring bb;
the central part of inner or flat side of the button a a being provided with a
depression or hollow as shown in Fig. 7-which also presses upon the corde when
the contrivance is in the position shown in the section in Fig. 10. This is the
normal position and it is made to assume it by the action of the helical spring bb
tending to pull the button ag inwards towards the stud d and plate c c the spring to
net thus being secured at its inner face or ring to the plate ce and its outer face or
ring to the inner surface of the button a a. When it is desired to release the cord e e
from the pressure of the stud d and inner side of button a a, this latter is either
pulled outwards by the handle for the cord ee may be pulled outwards by its
lower end in a manner corresponding to that as described in connection with Figs. 3
and 12 on releasing the cord or the handle of the button the spring resunes
its action and presses the cord e between the end of stud d and hollow or depression
in inner face of button a a. The principle of the contrivance here described and
illustrated in Figs. 7, 8, 9, and 10 may be applied to different designs or forms of
parts.
C
Although by the apparatus now described and illustrated in Figs. 7, 8, 9, and 10
the sudden drop of the blind cannot take place as noted when describing the
Belgian system illustrated which drop when it does through accident take place has
always the tendency to throw the window blind cord from out the pulley b b c c
Fig. 2 passing over even the deep flanges cc, it may be as well to adopt some such
simple contrivance as shown in Figs. 4, 5 and 6. In this a and b are narrow stripes
of tin or of lead soldered to and projecting from a part of the flanges c d of pulley.
After the cord has been wrapped round the pulley, the ends of the stripes
projecting beyond the edges of the flanges c d are bent inwards as at ef, nearly
meeting mid-way.
a b
As witness my hand this Seventeenth day of June Eighteen hundred and
COMPLETE SPECIFICATION.
Improvements in the Mechanism of Window Blind Furniture.
ROBERT SCOTT BURN Engineer Member of "The Institution of Mechanical
Engineers Oak Lea Edgeley Road near Stockport Cheshire. I 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:-
In my improved mechanical combinations applicable to window blind furniture I
propose two sets or classes. The first of these is adapted to that form of window
blind in which the cord used to raise or lower the blind proper is endless passing

page_text: round two pulleys. The second of these two classes is adapted to window blinds
in which the cord used to raise or lower the blind proper has one end free or loose
the other being attached or secured to and winding or unwinding from a pulley or
drum fixed to the end of the roller on which the material such as calico forming
the blind proper is securely fastened. The different forms of these two classes of
mechanical combinations are illustrated in the sheet of drawings left with
Provisional Specification and are described in detail in the following Specification.
In the mechanical combinations of the first class the leading feature is the employ-
ment of a vertical screw carried by a small frame secured to the woodwork of the
window framing. This screw carries at its upper end the pulley over which the
cord for raising or lowering the blind proper passes. By moving a button secured
to the lower end of the vertical screw in one direction or the other the pulley is
raised or lowered till the required degree of tension is given to the cord operating
upon the window blind proper. In one of the forms of the second class of
mechanical combinations above referred to the free end of the cord which operates
upon the blind proper is gripped or held fast, or released at any point of the drop
of blind desired by a lever and cam arrangement in which a spring is used to give the
gripping force required, to act upon the cord holding it in any position desired. In
another or the second of the forms of this class the free end of the cord is gripped
or held fast or released at any point desired through the medium of a circular
button with rounded front and knob or handle a helical spring being used to give
the gripping force required to hold the cord in any desired position,—and which
force is released either by pulling the knob of the button or hauling or pulling
outwards on the cord itself. All the parts are illustrated in the sheet of drawings
left with Provisional Specification and fully described in Specification following.
The mechanical appliance or contrivance by which window blinds are drawn up,
or raised and lowered as desired in which the main features are a pulley round
which the raising and lowering cord takes a half lap and the rack and spring by
which the position of the central stud of the pulley or its distance vertically from
the centre of the roller round which the blind is wrapped or from which it is
unwrapped is adjusted and the cord tightened as desired is well known and so largely
employed and this perhaps so from the comparative cheapness of the appliance that
it may be said to dominate over all other forms of window blind furniture.
This form of appliance has however many disadvantages. It is apt rapidly to
get out of order and there is from the very nature of the rack with its notches
catches or indentations placed at certain distances and these equidistantly from
each other a difficulty and this inherent in the device-to give the exact amount
or degree of adjustment to the pulley, so that the tightness of the cord is precisely
that which is required for the proper working of the window blind. The cord may
be too tight while the spring catch or detent of the pulley carriage engages with
one particular notch or catch of the rack, while the cord will be far too slack if
the spring catch or detent is placed in the notch of the rack next in succession and
immediately above it. The position of the detent if placed midway between these
two notches of the rack would be that which would give the precisely correct
amount of tightness of the cord. But this exact position of the rack is just that
which cannot be obtained inasmuch as there is no notch at the part by which to
keep the detent of the pulley carriage in place. Another disadvantage which this
particular form of window blind contrivance or appliance possesses is the difficulty
which is too frequently met with of giving any desired adjustment to the pulley
carriage and this from the strength or dexterity required to place the pulley
carriage in the position desired to give the window blind cord the exact degree of
tightness necessary, a difficulty not lessened by the unworkmanlike way in which
the contrivance is but too often made such as by the leaving of sharp corners
which are but too well adapted to act as weapons inflicting as they are too often
found to inflict wounds which if not so painful are at least disfiguring to the hands
of those who have been attempting the desired adjustment of the pulley carriage
an attempt not alwayssful.

page_text: Those disadvantages or defects present in what may be called the normal form
of window blind furniture have given rise to various attempts to introduce a
mechanical contrivance by which those defects could be remedied and an apparatus
not only thoroughly efficient and easily worked even by those ignorant of mechanical
adjustments. These improved contrivances in window blind furniture however
ingenious and really efficient are generally so complicated more or less that they
are of necessity much more expensive than the normal form of appliance already
described, while some of them are apt to get out of order involving time and
money expenditure in their repair or re-adjustment. The contrivances now in this
Specification to be described and which are illustrated in the accompanying
provisional sheet of drawings are attempts to introduce methods of raising and
lowering of window blinds-not of the class known as "Venetian" which while
efficient in operation and not liable to get out of working order are readily and
easily adjusted even by those least acquainted with mechanical contrivances and
their adjustments.
The first of the contrivances to be described in Figures 13-16 and 22 on sheet of
drawings left with Provisional Specification those being drawn full size or to
natural scale. In this contrivance the screw is the leading mechanical feature.
The pulley aa Fig. 16 round which the window blind cord bb takes a half lap the
upper lap of the cord taking on to, or engaging with the pulley of the window blind
roller above has its spindle carried by the forked or split head d d of the adjustable
carrier d deeee the lower part or stem of which is tubular or hollow as at f
the hollow part being tapped or screwed with a fine pitched screw as shown in
the sectional drawing in Fig. 16 this tube square or hexagonal in section on the
exterior, passes through the central eye of the upper steadying stud in small
bracket 99 which forms part of and projects from the attaching plate which is
screwed to the window frame part of which is shown at iii in sectional elevation in
Fig. 16 and in sectional plan in Fig. 17 which is taken on the line 1, 2, in Fig. 16.
The adjusting screw which is carried by the lower steadying eye or bracket m m
of the attaching plate his screwed with a screw of the same pitch at its upper
end as the pitch of the tapped or screwed interior of the tubular stem e of the
pulley a a carrying part dd while the lower end of the adjusting screw fis
provided with a finger and thumb button n. n. firmly secured, with a pin the outer
edge or rim of which button may be milled. The whole appliance or contrivance
is to be made of brass the only exception to this may be the button n n which if
preferred can be made of porcelain with metal sides of brass. When the appliance
or apparatus is fixed in place the attaching plate hhh firmly secured to the window
frame iii at a point low enough for convenience of working the upper or pulley a a―
carrying part d d is fixed in the position shown in the drawing Fig. 16. The upper
end of adjusting screw f/being engaged with the internal screw of the tubular
stem e to the extent of say one fourth of an inch or sufficient to give the screwed
stem a good hold of the interior screw of the tubular pulley carrying stem e.
The window blind cord is then passed through below the pulley a a and is then
carried up and passed over the upper side or half of the pulley secured to the roller
which carries the window blind-the two free ends of the window blind cord are
then brought together and securely sewn or fastened together. As it is not an easy
matter to adjust and fasten together the ends of the cord so as that it will embrace
both pulleys to the exact degree of tightness necessary to work the blind easily and
with certainty in its movements the cord when first adjusted will probably be too
slack very frequently this is the case normally or usually met with ordinary window
blinds of calico or other flexible material. In this case with the appliance just
described in order to tighten the cord bbit is only necessary to turn the button n n
from left to right when as the upper end of the stem ff engages with the internal
screw of the tubular part e it will cause this part to decrease in the direction of the
arrow o this carrying with it the pulley a a being on the spindle e e thus tightening
the cord which passes under and over the lower half of the pulley a a. As the
cord when made of the usual material is liable to be affected by the weather or

page_text: et at m
atmospheric influences a window blind adjusted so as to be property
may on the coming on of wet or of damp weather have its cord as bb Fig. 16 so
tightened as to make it a somewhat difficult matter to raise and lower it easily; the
cord in this way as conversely when it slackens by the influence of dry weather
becoming a simple yet in its way a suggestively useful hygrometer or weather
indicater. In the case here named with the appliance as illustrated in Fig. 16 all
that is necessary to be done is to turn the button n n from right to left when the
screwed stem or stud f. f. engaging with the internal screw of tubular part e causes
it and also the pulley carrying part to ascend in the direction of the arrow p thus
slackening the cord bb. It is obvious that with the appliance or contrivance here
illustrated the nicest degree of accurate adjustment of the pulley a a carrying the
window blind cord can be secured by simply turning the button n n either to
the left or the right as desired. In adjusting the apparatus as illustrated in
Fig. 16 the screwed stem may pass through a simple aperture in the centre or
eye of the bracket m m but in this case should the button n n be turned too much
round it may be disengaged or set free from the internal screw of part e and the
stem will be free to drop out of the bracket m m thus for the time disarranging
the apparatus till it is re-adjusted. In order to prevent this disarrangement the
foot of the screwed stem gg should be finished off with a collar or ruff as at Fig. 23,
the under surface of which rests upon and works on the upper surface of the
bracket mm Fig. 16 the tail or lower end of screwed stem/passing through the
eye of the bracket and being terminated by the button n n the tail working freely
within the eve of the bracket m m. In Fig. 17 we give a horizontal section of
partFig. 16 taken on the line 1-2 and in Fig. 18 a plan of upper side of pulley
carriage looking down upon it in the direction of the arrow o
Fig. 16.
Figs. 13 and 21 illustrates two modifications of the appliance shown in Fig. 16
and above described-but in both of which the same principle of arrangement as in
Fig. 16 is followed, those modifications having for their object the giving of more
Fig. 13 is a vertical
compact and more pleasing forms than that in Fig. 16.
section of the appliance or apparatus fixed to the window frame by the plate e c
and bracket d. The button e e milled or roughened on its outer edge by which the
adjusting screw is turned or made to revolve on its axis in the direction desired
either to lower or raise the pulley a works within a guard g g formed at the foot of
the casing or cylinder ii within which the adjusting screw is enclosed and the
lower part of the pulley carrying part slides up and down according as the
button e e is turned the pulley cord being slackened or tightened accordingly.
The guard yg is not carried completely but only part round as shown in side view
of lower part of Fig. 13 in Fig. 15 showing width 7 of guard. This enables part of
the button e to be exposed so as to be readily got hold of by the finger and thumb
in working it. In this modification of Fig. 16 the casing or outer cylinder iii
Fig. 13 is not made circular in section but hexagonal as shown in Fig. 14 which is
a plan on line 12 in Fig. 13. The drawing in Fig. 13 shows apparatus adjusted at
such a point that the pulley carrying stem has been pulled down sliding in the
outer case iii by the action of the screw f worked by the button e e to its lowest
point of descent in which the lower part of head rests upon the outer casing i i.
In Fig. 21 illustrate in vertical section drawn to natural scale or full size another
In this modification, the parts
modification of the appliance shown in Fig. 16.
lettered indicates the same parts shown in Fig. 13, the button guard being
somewhat differently arranged but exposing the button e e sufficiently to allow it to
be easily worked as shown at e' el in Fig. 23, which is a view of the lower part of
Fig. 21 taken as looked upon in direction of arrow h.
In another system of working window blinds the cord is not an endless one as in
the contrivances or appliances just described but is worked with a loose or free end
the other end being wound on or unwound from the window blind roller as desired.
The contrivances now to be described and illustrated in Figs. 7, 8, 9, 10, 11, and 20
are based upon an appliance which as it is much used in Belgium for the purposes
of this Specification propose to designate it as the "Belgian." Of this the following
B

page_text: brief description while explaining its advantages on the score of simplicity and
consequent cheapness of make and the readiness with which it can be fitted up and
worked or used will also show its disadvantages or weak points which by my
improved arrangements I propose to get rid of, thus making it an effective easily
worked, readily fitted up and a cheaply made apparatus for raising and lowering
window blinds of the ordinary kind made of a pliable fabric such as calico.
66
"
The
Belgian appliance may be here described by drawings as in Figs. 1, 2, 3, 4, 5,
and 6 which it is to be understood are not to be taken as drawings to scale but
merely as diagrams serving to make clear the character of the system.
To one end of the window blind roller part of which is shown at side elevation in
Fig. 2 at a a a pulley made cheaply of tin with deep flanges cc is firmly secured.
The outer flange of pulley carries at its centre a projecting stud or arbor serves as
one of the spindles upon which the roller revolves as bearings fixed to the window
side framing. Round the pulley ba cord eee Fig. 1 is wound being secured at
one end to the pulley. To the window blind roller à a Figs. 1 and 2 the outer end
or edge of the window blind f Fig. 1 is nailed in the usual manner. When the
roller is put in place the window blind is itself wound by hand or wrapped by hand
till the full length of the blind is taken up by and wound upon the roller. The
lower or outer edge of the blind ff is finished off with a loop into which a bar or
slat g is passed. This acts as a weight sufficient to pull down the window blind or
cause it to drop in the direction of arrow i Fig. 1, when the blind with weight g is
left free, and to gradually unwind it from the roller a a Figs. 1 and 2. This
unwinding of the blind causes the roller to revolve on its axis and to wind on the
drum of the pulley bee a length of the cord ee Fig. 1, equal to the length of
the window blind ffy which has been unwound from its roller a a by the weight or
bar dropping in the direction of the arrow i. If now when the window blind loop
and bar is at the lowest point of its drop or descent it is desired to raise the
window blind ff, the cord ee Fig. 1 is taken hold of by the hand and pulled in the
direction of the arrow m the action unwinds the cord from the pulley bee Fig. 2
and as it is unwound it correspondingly winds up the blind ffg on to the window
blind roller a a in the direction of arrow h. If at any point the cord was freed
from the control of the hand, the weight or slat or bar Fig. 1 would begin to act
and would pull down the blind f in the direction of arrow i.
り
A contrivance is therefore obviously required to maintain the window blindf
Fig. 1 at any point in the direction of its drop that is to keep it suspended. This
is met with in another part of the "Belgian" system illustrated in the diagram in
Fig. 3 in which g, h, a, is a cone-shaped body hung and working upon a central stud
or pin c which is a little eccentric to the true centre a of the semi-circular end.
The cam shaped part g, h, a is jointed by the pin c between two jaws or plates one
of which is shown at d projecting from the surface and forming part of the back
plate d d d secured firmly to the window frame by two screws. The centre pin or
stud is so placed in relation to the cam g, h, a and the back plate d d d that a space
is left free or open to admit of the window blind cord ƒ ƒ corresponding to dee in
Fig. 1 being passed through behind the end of the cam a and the front of plate ddd
which cordis fixed at any point of its length-correspondingly fixing the window
blind in Fig. 1 at any desired height by pressing on the end or handle gh
Fig. 3 so that it moves downward and inward as in the direction of the arrow the
inner side or end of cam a pressing on and jamming up so to say the cord ff between
it and the outer face of the back or attaching plate d d d. And in order to give
the main edge of cam at a a better grip of cord ffit is made saw edged or rough.
Fig. 12 illustrates the position which the cam g, h, a corresponding to the part
similarly lettered in Fig. 3 assumes when the cord is held tightly between the
edge of end a and the outer face of attaching plate d d e.
When it is desired that
the window blind as ffg Fig. 1 should be dropped the cord is released by
raising in the direction of the arrow Fig. 12 the outer end or handle yh of the
cam g, h, a and bringing it towards the position as shown in Fig. 3, the inner edge
and a of the cam is thus released from pressing upon or jamming up the cord i

page_text: against the plate d d secured to the window frame e e Fig. 12. When the cord ƒƒ
is thus released the weight of bar or slat g Fig. 1 carried in the loop at lower edge
of window blind ff brings or pulls down the blind to any point desired and it is
fixed or kept there by pressing down the end of the cam in direction of arrow n
Fig. 12 till it assumes the position as there shown. When it is desired to raise the
window blind causing the bar or slat g Fig. 1 to ascend in direction of arrow k, hold
is taken of the end g of handle of the cam as in Fig. 12 the cord ff being taken
in the other hand and when the pressure of the end a on cord is released by
lifting it in direction of arrow i, the cord ff is pulled vertically downwards by
the other hand till the required height of the window blind bar a Fig. 1 is reached
when the end of cam g ha Fig. 12 is passed down in the direction of arrow u and
the cord is once more jammed up against the face of plate d d and retained in the
position.
Efficient up to a certain point this "Belgian" system is as now described and
illustrated, it presents notwithstanding this great disadvantage namely that to work
it with precision and readiness the two hands must be employed. Thus supposing
that it is desired to drop the window blind gently if the cam g, h, a Figs. 3 and 12
raised from position shown in Fig. 12 to that shown in Fig. 3 and the cord thus
suddenly released from the action of the cam, the window blind will in virtue of the
weight of barg Fig. 1 drop suddenly and coming more or less violently against the
window sill the cord will probably be thrown out of the pulley bb Fig. 2 which it
will take some time and trouble to replace. The only way in this case is to take
hold of the cord ff by one hand while the cam g, h, a is released from pressing
upon it by lifting the end g Fig. 12 by the other; thus giving the power to regulate
the speed of falling blind bar g Fig. 1 to any point desired. If on the contrary it
is desired to raise the window blind it can be done readily enough by means of one
hand only and this by raising the cord Fig. 12 in the first place in the direction
of the arrow and dotted line m which will release the grip of the cam face at a on
it, when by pulling the cord towards the person the blind will be raised; but if the
cord is released from the hand the weight of g Fig. 1 will bring the window blind
suddenly down. To prevent this when the cord has been pulled far enough the
cam is then brought to bear upon the cord as in the position of Fig. 12, when both
cord and cam may be let go and the window blind will be kept suspended at the
point desired. But it is not always easy to get close enough to the window in
order to use the two hands in working the apparatus in consequence of flower
stands, work tables or the like being placed in front of it.
66
66
"
In order therefore to make the Belgian" system of working window blinds as
now described more easy and certain, capable of being worked by one hand only
some modifications of it is necessary. With this in view I have designed an
appliance which is self acting and self adjusting, one form of it being illustrated in
Fig. 20 in accompanying sheet of drawings which sufficiently indicates the nature
of the modification. The principle features of it are almost identical with the
Belgian" appliance, the difference between them lying in the adaptation of a
helical spring carried between the extended jaws or snags one of which is shown
ate e corresponding to d d in Fig. 1. The inner end of spring pressing on the
outer or upper edge g of cam a b c keeps the serrated or roughened edge a always
in contact with or exercising a "grip
When the window
upon the cord d d.
blind is desired for example to be lowered the cord d d is released from the action
of the cam passed on by the spring by simply raising the cord d d in the direction
of the dotted lines, and thereafter pulling it downwards till the point is reached
at which the window blind is desired to hang when by letting the cord out of the
hand, the spring resumes its action and the grip of the cam upon the cord dd
thus retaining the blind in the desired position. In dropping the window blind the
outer end of the cam can be used as a handle so to regulate the pressure of the
spring that the blind will descend slowly, and when the point of its descent is
reached as desired by letting the end of the cam ge, the spring ƒ will at once act
and keep the cord d d fast gripped.

page_text: The same principle of securing the grip taken hold of the window blind cord
through the action of the helical spring as illustrated in Fig. 20, is adopted in the
form of contrivance I have designed and as illustrated in Figs. 7, 8, 9 and 10 in
accompanying provisional sheet of drawings. In this the appliance takes the form
of a hemi-spherial button a a Fig. 7 connected with and attached by a helical
spring to the holding on plate ce which is screwed in the ordinary way to the
window frame of which is shown at d. The central part of the plate e e is provided
with a projecting cylindrical study the outer and free end of which is hollowed
out to receive part of, and embrace the window blind cord e corresponding to ff
Fig. 12 or dd Fig. 20. The inner or flat side of the button a a is provided
with a semi circular depression into which part of the corde falls, when the
button a a in its normal position shown in the diagram in Fig. 10 and it is pulled
inwards, towards the plate ce by the action of the spring which is connected at
its inner side or end with the plate ee and secured at its outer side or end to the
inner or flat face of the button a a. The spring is made strong enough to keep
such a grip at the cord e when the button a a is closest to the plate ce that the
window blind will be retained in any position desired.
When it is required to
drop the window blind, the cord e is released from the action of the spring by
simply taking hold of the handle or knob of the button a a and pulling it
outwards as shown in Fig. 7 when the cord e is freed from the pressure between
the stud and the surface of depression on the inner face of button a a. Or in
place of manipulating the button thus by the knob it may be more convenient to
pull the lower end of the cord e outwards and upwards as shown by the dotted lines
at m Fig. 12, this action pulls the button a a Fig. 7 outwards releasing the cord
from the grip of stud g. On releasing the spring is free to resume its action
pressing the stud upon the cord. Generally the best way is to manipulate the
button and spring by means of the handle or knob forming part of the button.
Although by the apparatus now described and illustrated in Figs. 7, 8, 9, and 10
the sudden drop of the window blind cannot take place as it can in certain ways of
using the old form of the Belgian system illustrated in Figs. 3 and 12 which drop
when it does take place has always the tendency to throw the cord as ee Fig. 1 out
of connection with the pulley bee Fig. 2 by jerking it so to say over and passed
the deep flange, it may be as well to adopt some such simple contrivance as
Figs. 4, 5 and 6. In these a band 6' are narrow strips of tin soldered at one end
to one point near the edge of pulley flange ee Fig. 4, the other end projecting
freely beyond the edge of flange as shown at Fig. 4. When the cord has been
fully wrapped round the pulley bb Fig. 2 the projecting ends of strip as at 6 Fig. 4
and at a Fig. 5, are bent inwards towards the centre of pulley so as to lie over
the enclosed space between the flanges as shown at eFig. 6. By this simple
arrangement the cord as ee Fig. 1 is enclosed within the space between the flanges
and cannot leap out or be jerked out, the plates ef preventing this.
Having now particularly described and ascertained the nature of my said inven
tion and in what manner the same is to be performed 1 declare that what I
claim is
First. The combination of mechanical parts as illustrated in Figs. 16, 17, 18, 13,
14, 15, 21, 22, and 23 of the sheet of drawings left with Provisional Specification
and which I have fully described in preceding Specification.
Second. claim the peculiar arrangement of mechanical parts constituting an
improvement upon, the contrivance used for grapping or retaining the window blind
cord at any point of its length desired, and to which in preceding Specification 1
have given the name of " Belgian," as it constitutes an important part of the
window blind furniture much used in Belgium. The improvement which I claim
is shown in Fig. 20 in the sheet of drawings left with the Provisional Specification,
and which I have fully described in preceding Specification.
Third. I claim the combination of mechanical parts to which in preceding
Specification I have given the general name of a "button" by which the window

page_text: blind cord which regulates the rise and drop or fall of the window blind, can be
gripped, retained or held fast at any point of its length desired or quickly released
from its grip or hold of the cord should it be desired to allow the cord to run free
from any point of its length. This combination of mechanical parts is illustrated
in Figs. 7, 8, 9, and 10 of sheet of drawings left with Provisional Specifications
and described in preceding Specification.
As witness my hand this Nineteenth day of February One thousand eight
hundred and ninety-one.
ROBERT SCOTT BURN.