Year: 1885

page_text: We, WILLIAM HOLMES NISBET, Mavisbank Partick, Lanarkshire, Engineer, and
WILLIAM WRIGHT VIRTUE of 6 Vulcan Street Springburn Lanarkshire, Engineer,
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 :-
Our invention has for its object to simplify and improve the construction of self
acting window blind apparatus of the kind commonly employed for operating the
blinds of railway carriage windows. To that end we fit within a cap on a bracket
at one end of the blind roller or barrel a volute spring arranged to effect the
rotation of the barrel for raising the blind, and in a like cap on a bracket at the
opposite end we fit a retaining ratchet to prevent the turning of the barrel by
the weighted blind, and this ratchet we connect to the barrel by a friction pad or
brake which holds it at any position to which it may be placed by hand, but which
slips or yields when the blind is drawn down.
In the accompanying drawings which illustrate our invention figure 1, is a longi-
tudinal vertical section of the barrel and operating mechanism of a balanced blind
applicable for railway carriage windows and figures 2 and 3 are respectively a
sectional elevation of the bracket and cap carrying the devices for holding the
blind and an elevation of the bracket and cap containing the operating volute
spring. The blind A, is suitably weighted and is secured in the usual way on the
roller or barrel B, which is carried on stud axes C, C¹, secured in the end covers D, D¹,
of the barrel, and resting in bearings in the cap brackets E, E. Within the cap E,
is secured the end of a long volute or coiled spring F, whose other end is secured
to a pin G, fitted in the end cover D, of the blind roller or barrel B, and this spring
tends to turn the barrel in the direction shown by the arrow to roll up the blind.
The drawing down of the blind by hand effects the winding of the spring which
gradually unwinds as it again rotates the barrel to effect the raising of the blind,
this action of the volute spring being the same as occurs in ordinary balanced
blinds in which a helical spring is carried along the length or part of the length of
the barrel.
On the stud axis C, at the opposite end of the barrel B, is fitted a sleeve H, on
which a ratchet I, is formed or fitted, and the teeth of this ratchet engage with a
pawl J, which is jointed to the stationary cap or bracket E¹, the ratchet teeth being

page_text: so formed that the pawl may slip over them when the barrel B, is turned in the
direction for rolling up the blind but that the pawl may hold the ratchet while the
blind is unrolled or drawn down. Upon the sleeve H is fixed a volute spring or
coiled steel strip K, whose free end is fitted with a brake or friction pad L, bearing
on the inner surface of the end cover D¹, of the barrel which is hollowed out to 5
receive the brake device. The brake or friction pad bears lightly on the barrel
cover D¹, and prevents the weight of the blind and of a bar or rod M, fitted in it,
from turning the barrel while it yields to permit of the drawing down of the blind
by hand. The tendency of the spring F to turn the barrel and roll up the blind
is thus balanced by the weight of the blind and of the bar or rod M, fitted in it;
but when this weight is relieved by hand, the spring at once acts to turn the barrel
and roll up the blind, the ratchet I, which prevents the unrolling of the blind being
free to slip under the pawl J, as before mentioned.
.
The brackets E, E which carry the roller or barrel of the blind are secured by.
screws or otherwise to the framing on either side of the window pane and by
simply unfastening either of the brackets the roller may be readily removed for
renewal or repair or to give access to the operating devices. The arrangement of
the coiled spring F, within the cap E is a convenient one for this purpose, but the
ordinary helical spring arrangement may be used though not so advantageously.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
(1.) The combination of parts constituting the improved self-acting window blind
apparatus substantially as herein described with reference to the accompanying
drawing.
(2.) In self-acting window blind apparatus the arrangement of the brake or
friction pad L, as and for the purpose specified.

page_text: We, WILLIAM HOLMES NISBET, Mavisbank Partick, Lanarkshire, Engineer, and
WILLIAM WRIGHT VIRTUE of 6 Vulcan Street Springburn Lanarkshire, Engineer,
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 :—
Our invention has for its object to simplify and improve the construction of self
acting window blind apparatus of the kind commonly employed for operating the
blinds of railway carriage windows. To that end we fit within a cap on a bracket
at one end of the blind roller or barrel a volute spring arranged to effect the
rotation of the barrel for raising the blind, and in a like cap on a bracket at the
opposite end we fit a retaining ratchet to prevent the turning of the barrel by
the weighted blind, and this ratchet we connect to the barrel by a friction pad or
brake which holds it at any position to which it may be placed by hand, but which
slips or yields when the blind is drawn down.
In the accompanying drawings which illustrate our invention figure 1, is a longi-
tudinal vertical section of the barrel and operating mechanism of a balanced blind
applicable for railway carriage windows and figures 2 and 3 are respectively a
sectional elevation of the bracket and cap carrying the devices for holding the
blind and an elevation of the bracket and cap containing the operating volute
spring. The blind A, is suitably weighted and is secured in the usual way on the
roller or barrel B, which is carried on stud axes C, C¹, secured in the end covers D, D¹,
of the barrel, and resting in bearings in the cap brackets E, E¹. Within the cap E,
is secured the end of a long volute or coiled spring F, whose other end is secured
to a pin G, fitted in the end cover D, of the blind roller or barrel B, and this spring
tends to turn the barrel in the direction shown by the arrow to roll up the blind.
The drawing down of the blind by hand effects the winding of the spring which
gradually unwinds as it again rotates the barrel to effect the raising of the blind,
this action of the volute spring being the same as occurs in ordinary balanced
blinds in which a helical spring is carried along the length or part of the length of
the barrel
On the stud axis C, at the opposite end of the barrel B, is fitted a sleeve H, on
which a ratchet I, is formed or fitted, and the teeth of this ratchet engage with a
pawl J, which is jointed to the stationary cap or bracket E¹, the ratchet teeth being

page_text: so formed that the pawl may slip over them when the barrel B, is turned in the
direction for rolling up the blind but that the pawl may hold the ratchet while the
blind is unrolled or drawn down. Upon the sleeve H is fixed a volute spring or
coiled steel strip K, whose free end is fitted with a brake or friction pad L, bearing
on the inner surface of the end cover D¹, of the barrel which is hollowed out to
receive the brake device. The brake or friction pad bears lightly on the barrel
cover D¹, and prevents the weight of the blind and of a bar or rod M, fitted in it,
from turning the barrel while it yields to permit of the drawing down of the blind
by hand. The tendency of the spring F to turn the barrel and roll up the blind
is thus balanced by the weight of the blind and of the bar or rod M, fitted in it;
but when this weight is relieved by hand, the spring at once acts to turn the barrel
and roll up the blind, the ratchet I, which prevents the unrolling of the blind being
free to slip under the pawl J, as before mentioned.
The brackets E, E¹ which carry the roller or barrel of the blind are secured by
screws or otherwise to the framing on either side of the window pane and by
simply unfastening either of the brackets the roller may be readily removed for
renewal or repair or to give access to the operating devices. The arrangement of
the coiled spring F, within the cap E is a convenient one for this purpose, but the
ordinary helical spring arrangement may be used though not so advantageously.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
(1.) The combination of parts constituting the improved self-acting window blind
apparatus substantially as herein described with reference to the accompanying
drawing.
(2.) In self-acting window blind apparatus the arrangement of the brake or
friction pad L, as and for the purpose specified.