IMPROVEMENTS IN SPRING ROLLERS FOR BLINDS AND OTHER PURPOSES
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by Robert James Miller at the Office of
tho Commissioners of Patents on the 5th May 1876. Partly a communication
from abroad by Stewart Hartshorn, of New York, United States of America.
ROBERT JAMES MILLER, of Weymouth Street, in the County of Middlesex,
Patentee. " IMPROVEMENTS IN SPRING ROLLERS
FOR BLINDS AND OTHER
PURPOSES."
This Invention rolates to improvements in spring rollers for blinds and other
purposes.
According to my Invention I take an ordinary blind roller of wood or other
material, and if of wood I bore it out longitudinally for a certain portion of its
length. In this bore or chamber I lodge a helical spring surrounding an inner
spindle of wood, tin, or other material, the spring being attached at one end to the
said spindle and prevented from turning bodily round within the bore by being
attached at its opposite end to a plug inserted in the inner end of the bore, and
fixed to the roller by a pin or other suitable means. The said spindle has at its
outer end a metal head, the extremity of which is supported in a bracket, so that
the spindle cannot turn round. The length of the spring and spindle are deter-
nined by the number of revolutions required to wind up the blind, and in order
that the spring may occupy as small a space as possible I form it of a square
sectional steel wire, the coils of which will lie very closely together, and may be
wound up very tight without causing the spring to buckle, and will also give
greater strength for the space occupied. When the spring is thus formed it is very
seldom necessary to carry it right through the roller, as is usually done with the
spring as ordinarily constructed of round wire. An advantage gained by the spring
and spindle not being carried right through is that the roller may be cut at the
blank end to the required length without any special fitting in the make of the
roller.
If the roller be of metal it is made with a telescopic joint, the spindle being
supported at its outer end in a bracket so that it cannot turn round, and at its
inner end in a bearing in the plug inserted in the bore of the roller, and the opposite
end of the roller being supported on a pin the roller can be turned around the
spindle. The end of the roller is fitted with a circular metal plate with a flange
projecting outwards, through which plate the metal head of the spindle passes, and
to the outer face of which plate are attached two pawls working into a notche cut

page_text: in the upper side of the metal head of the spindle. These pawls act by gravity, so
that only the one at the top will fall into the notch in the spindle as the pawl is
brought over it by the revolution of the roller, the othe pawl falling away from
the spindle as far as the rim on the metal plate will allow.
The action is as follows:-When the blind is pulled down the roller turns freely 5
under the pawls, and tension is put on the spring. When the blind has been
brought to the position required the roller is allowed to turn back gently until one
of the pawls falls into the notch and locks it. To raise the blind it is first drawn down
a short distanco sufficiently to free the pawl, and then the blind is allowed to run
up rapidly, which will cause the roller to turn fast enough to keep the pawls by
centrifugal force out of the notche.