IMPROVEMENTS IN THE CONSTRUCTION OF VENETIAN BLINDS, AND IN MECHANISM TO BE USED IN CONNECTION THEREWITH
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Samuel Mitchell and John Mitchell
at the Office of the Commissioners of Patents, with their Petition, on the
22nd December 1866.
We, SAMUEL MITCHELL and JOHN MITCHELL, of Cranbourn Street, Leicester
Square, in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF VENETIAN BLINDS, AND IN
MECHANISM TO BE USED IN CONNECTION THEREWITH," to be as follows:-
This Invention consists of certain arrangements and mechanism by means
of which the laths of Venetian blinds can be readily placed and retained at
any desired angle. Instead of employing the double check line hitherto used
for the alteration of the position of the laths a single line is adopted for that
purpose, and which is, by preference, constructed of copper or other wire cord,
or of any other suitable material possessing the requisite degree of strength
and flexibility. The line is passed upwards through a mortice hole and over
a pulley in the left-hand end of the pulley head (or upper frame of the blind),"
the same being then carried along the pulley head and passed down through
and over a second mortice hole and pulley in the centre of the pulley head,
and secured to the front edge of the tumbler lath, the latter being the thick
lath next to the pulley head, and to which the rest of the blind is hung. In
cases in which great strength is desired more than one line may be secured.
to the tumbler lath, as above described, in which case additional pulleys
would be required. The box rollers which are usually fixed in the pulley
heads of Venetian blinds, and over which the pieces of rolling tape work, are

page_text: dispensed with, and in their places are formed two mortice holes parallel to
each other. The short pieces of webbing by which the rest of the blind is
hung to the pulley head are passed up and down through these mortices and
nailed or secured to the tumbler lath in the usual manner, or, if preferred,
two holes can be made in place of the mortices, and cord used instead of
webbing. The webbings or cords are then strongly nailed or otherwise
secured on the top of the pulley head in such a position that all the laths of
the blind will lap closely together as they should do when a strong light is on
the window. Such will be the position of the laths when the blind is hung in
its place. In order to open the laths of the blind it is only necessary to pull
the check cord firmly, when, by reason of the same being connected with the
front edge of the tumbler lath from which all the other laths are suspended
the front edge of the former is raised, thereby bringing each of the other laths
into a similar position, and thus opening the blind. For the purpose of
keeping the laths open at any desired angle, a latchet formed of brass or
other suitable metal or material is attached to the lower end of the check cord,
the same being equally divided into any desired number of stops or notches,
and which latter fit into a metallic fork attached to a plate and screwed or
otherwise secured to the side of the window linings, or in any other con-
venient position. A ring is attached to the latchet by which it is readily
shifted in and out of the fork; when the latchet is taken out of the fork the
laths lap closely together by their own weight, whilst by fixing the latchet at
the different stops or notches the laths will be placed and retained at any
desired angle.