Improvements in Venetian Blinds.
Year: 1894

page_text: Date of Application, 24th Mar., 1894-Accepted, 5th May, 1894
COMPLETE SPECIFICATION.
Improvements in Venetian Blinds.
I, ADOLF HERMAN LINDSTEDT (of the Firm of P. Ericsson & Co.) of Nos. 3
& 5 Sodra Vagen, Gothenburg, Sweden, Blindmakers do hereby declare the
nature of said invention and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement:-
"
The objects of my invention are to simplify and economise the cost of making and
fitting Venetian blinds; to facilitate the handling of same, in raising and lowering
them and in opening and closing the laths or "louvres to admit or exclude light
in graduated proportions, and the entire removal when required (as for cleaning the
blinds or windows).
According to my invention all the mechanism for working the blind is open to
view instead of being enclosed in a casing involving the complete stripping or
removal when a cord breaks or any part gets out of order. The blind is much
lighter owing to the laths being made much thinner than is usual and the raising
and lowering, also the opening and closing, can be effected by pulling the cords in
any direction and with very slight exertion and the blind stays automatically at any
height when the cords are released, whilst the laths cover the whole width of the
window sashes. When cleaning of the windows is required, or of the blinds
themselves, they can be taken down as easily as an ordinary roller blind and
without the aid of any tools, and as readily replaced.
On the accompanying drawings I illustrate my invention as it may conveniently
be put into practical use. and as I. propose generally to apply it, subject to
modifications in details to meet different cases.
Figs. 1 and 2 shew the turning bar, forming the top lath, in side and end views
with the mechanism by which the required operations are performed, the side view
being of portions only of the full length.
Figs. 3, 4, 5, 6, 7, 8, and 9 shew details of the mechanism by which the laths or
"louvres" are opened in graduated proportions or entirely closed, and
Fig. 10 is a detail of the sustaining spring stopper which automatically holds the
blind at any required height when the cords are released.
"
Referring to Figs. 1 and 2, A A' are the brackets screwed to the window head B;
C is the turning bar forming the top lath from which the blind laths or "louvres
are suspended by tapes in the usual manner, and upon the front of this top bar all
the mechanism connected with the raising, lowering, and retaining the blind is
fixed, and the opening and closing mechanism of the laths or "louvres" is also
actuated by its movements. DD are the running eyes for the cords E E¹ to raise
and lower the blind which eyes I have made of smooth glass, by preference, but
other material may be used. F is the sustaining spring screwed or fixed upon the
turning bar C and is raised by the cord G to release the cords E E' when lowering
the blind, and automatically grips them at any required height. The turning bar
or top lath C is supported freely in the brackets A A₁ at each end, the bracket A
having attached to it a curved ratchet H, working radially upon a pin J, and into
the teeth of the ratchet a pin K in the end of the turning bar or lath C engages as
it is pulled over by the cord L the teeth holding the pin at the successive stages,
each of which opens the laths of the blind progressively as the turning bar or lath
is pulled further over as shewn by Figs. 3, 4, 5, 6, 7, 8, and 9 till the pin reaches
the curved nose of the ratchet H when it lifts the ratchet clear of its return path,
see Fig. 9, and a swinging "pawl" M rests upon a stud N in the bracket, till the
cord L being released the top lath C and the pin K return by gravity, the
pin being clear of the ratchet teeth and knocking the pawl M off the stud N allows

page_text: the ratchet to fall into its normal position resting upon the pin K, and the turning
lath C is now in the position shewn (see Fig. 3) the blind being closed and
darkened with the laths overlapping toward the light. The varying positions of
the turning bar or lath C and of the blind laths are shewn in rotation by Figs. 4,5,
6, 7, and 8.
The automatic stopper Fig. 10 consists of a spiral spring S coiled around the
axle on which the serrated arm of the stopper works, to which one end is
attached, the other end being secured to the arm O which, being pulled by the
cord G against the resistance of the spring releases the cords E E' from between
the stopper and the pulley P, so that the blind can be lowered to the required
extent and when the cord G is released the stopper, by the action of the spring,
presses the cords against the pulley and holds the blind but does not prevent the
blind being raised by pulling the cords E E'.
Having now particularly described and ascertained the nature of my said inven-
tion and in what mauner the same is to be performed I declare that what I
claim is :-
1st. The improvements in Venetian blinds consisting in suspending the blind
from a turning bar, forming the top lath, which carries all the mechanism for
operating the blind, and which is supported freely in brackets secured to the window
head, so that the turning bar with the blind can be readily removed from the
brackets for cleaning, leaving the whole window clear, and as readily replaced,
substantially as described and shewn.
2nd. In combination with the turning bar from which the blind is suspended the
application of a radial toothed ratchet working freely by gravity on a centre in one
of the brackets into the teeth of which a projecting pin in the end of the turning
bar engages successively as the bar is turned, by pulling a hand cord, so as to allow
the angles of the laths or "louvres" and regulate the admission of light from
"closed" to "full open," and thence toward closing at the opposite angles, and to
return automatically to "closed" by the pin raising the ratchet teeth clear of its
return path, a pawl resting on a stud in the bracket supporting it, until the pin in
the turning bar knocks it off in returning to its first position, when the ratchet falls
and rests on the pin in the turning bar, substantially as described and shewo.
3rd. The application to Venetian blinds of smooth eyes of glass or other suitable
material through which the cords for raising and lowering the blind run freely and
without friction, instead of rollers or sheaves, and of a spring catch for automatically
sustaining the blind at any required height which catch being operated by a cord
releases the cords to allow the blind to be lowered. Such eyes and spring catch
being fixed upon a turning bar, or equivalent top bar, from which the blind is
suspended, readily accessible for examination or repairs, substantially as described
and in one form shewn.
Dated this 24th day of March 1894.
T. J. DANSON, F. Inst. P.A.,
Agent for Applicant.