Improvements in and connected with Window Blinds.
Year: 1898

page_text: Date of Application, 16th Mar., 1898
Complete Specification Left, 29th Oct., 1898-Accepted, 7th Jan., 1899
Improvements in and connected with Window Blinds.
I, GAVIN STRUTHERS ROBB, of 43, Carnarvon Street, in the County of the City of
Glasgow, North Britain, Chemist, do hereby declare the nature of this invention
to be as follows:-
-
This invention which relates to improvements in and connected with window
blinds, of the pawl and ratchet type, has for its object to construct these in the
manner and for the purpose of rendering the working parts interchangeable.
In carrying the invention into practice I employ a spur wheel which performs
all the functions of a ratchet, wheel which it indeed is, the formation of whose
teeth are slightly undercut or of wedge configuration so that they shall engage
the pawl whether the spur wheel is made to rotate in the one direction or the
other.
To engage the teeth of the said spur wheel I employ a pawl formed with a
double head or duplex engaging surfaces. The said pawl is free to swing to
either side of the box to which it is attached by a pivotal pin riveted on to the
back thereof and is efficient in its action whether swinging to the one side or other.
Or I may form the said pawl with a heel or extension at its pivotal end, which,
without interfering with its due engagement with the spur wheel, will when the
latter is removed with the roller, come in contact with the wall or rim of the box
and so be prevented from falling into the vertical position and being turned to the
side opposed to the one from which it is intended to operate. This form of pawl
is attached to the back of the box by means of a pivotal screw pin which is remov-
able at will in order to reverse the pawl when required.
Improvements in and connected with WIDOW D
I, GAVIN STRUTHERS ROBB, of 43, Carnarvon Street, in the County of the City of
Glasgow, North Britain, Chemist, 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:-
This invention which relates to improvements in and connected with window

page_text: blinds of the pawl and ratchet type, has for its object to construct these in the
meuner and for the purpose of ending the working parts interchangeable.
In carrying the invention into practice I employ a spur wheel which performs
all the functions of a ratchet wheel, which it indeed is, the formation of whose
teeth are slightly undercut or of wedge configuration so that they shall engage
the pawl whether the spur wheel is made to rotate in the one direction or the
other.
To engage the teeth of the said spur wheel I employ a pawl formed with a
double bead or duplex engaging surfaces. The sail awl is free to swing to
either side of the box to which it is attached by a pivotal pin riveted on to the
back thereof, and is efficient in its action whether swinging to the one side or the
other. Or I may form the said pawl with a heel or extension at its pivotal end, which
without interfering with its due engagement with the spur wheel, will when the
latter is removed with the roller, come in contact with the wall or rim of the box
and so be prevented from falling into the vertical position and being turned to the
side opposed to the one from which it is intended to operate. This form of pawl
is attached to the back of the box by means of a pivotal screw pin which is
removeable at will in order to reverse the pawl when required.
In order that my invention may be properly understood and readily carried into
effect I have hereunto appended one explanatory sheet of drawings in the several
figures of which corresponding parts are marked with the same letters of reference.
Figure 1 is a box of a window blind roller known as Scotch blind furniture to
which my improvements are applied.
Figure 2 is an end view of the spur or ratchet wheel corresponding to the one
shewn in Figure 1, and made in accordance with my invention.
Figure 3, is an end view of the pawl also corresponding to Figure 1.
Figure 4 is a front view of a box corresponding to Figure 1 illustrating a
modified form of pawl with the engaging spur or ratchet wheel removed.
Figure 5 is an end view of the pawl corresponding to Figure 4.
Figure 6 is a front view of a further modified form of pawl.
Figure 7 is a similar view to Figure 1, of a box fitted with a further modified
form of pawl engaging a spur or ratchet wheel made in accordance with and con-
stituting my invention.
Figure 8, is an end view of the spur wheel corresponding to Figure 7.
Figure 9 is a front and end view respectively of the pawl also corresponding to
Figure 7.
Figure 10 is a part longitudinal section and side elevation of a blind roller
illustrating the fittings shewn in Figure 7, 8, and 9.
Figure 11, is a part front view of a box fitted with a modified form of pawl all
hereafter more fully described.
Referring to Figures 1, and 2, the spur wheel A, which is rivetted or otherwise
mounted on the end of the blind roller is inserted axially into the box so that it
is made to engage the pawl B, as shewn in Figure 1. The spur wheel A, is pro-
vided with teeth C, which are slightly undercut and which are adapted to engage
the pawl B, whether the said wheel is rotated in the one direction or the other
relatively to the side from which the pawl B, is allowed to swing in the box. The
pawl B, is formed as shewn with a double head or duplex engaging surfaces which
engage the ratchet or spur teeth of the wheel whether placed to the one side or
the other of the box. In the said Fig. 1, the ratchet or spur wheel A, rotating in
the direction indicated by the arrow in full lines is engaged by the pawl B, at
the left hand side of its engaging surface. The said ratchet or spur wheel when
rotating in the direction indicated by the arrow drawn in dotted lines will be
engaged by the said pawl B, with its right hand engaging surface. The pawls
illustrated in Figures 1 and 6, also in Figure 7, have their pivotal pins rivetted to
the back of the box. The pawls B, illustrated in Figure 4, 5, and 11, have their
axial or pivotal pins screwed into the box to facilitate their being placed either to

page_text: the one side or the other from which it is intended they shall operate in the box.
By virtue of a heel extension b, which comes in contact with the circular wall of
the box, the pawl B, is prevented from falling into a vertical position.
This provision is made to overcome certain disadvantages which are or may be
experienced when taking down the blind roller and replacing it in position, by
the pawl accidentally falling into the vertical, whereby the inexperienced may
put it to the side from which it is not intended to operate and thereby reverse
the direction of the roll of the blind. The formation of the pawl illustrated in
Figs. 7, 9, and 11, has a square or rectangular engaging surface for the proper
engagement with the spur wheel shewn more particularly in Figs. 7 and 8. This
spur wheel is formed of wedge like teeth the apexes of which are projected in an
outward direction. The mode of operation of the spur wheel and pawl will be
fully understood reference being had to Figure 7, wherein the end and object
fulfilled by the device already described and referred to in Figure 1, will be
similarly met in this figure.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. In window roller blind furniture of the pawl and ratchet type constructing
the ratchet wheel which is rigidly mounted upon the one end of the blind roller
with teeth of wedge or dovetail configuration, which shall engage the pawl, without
detachment or removal, whether the blind roller be turned in the one direction
or the other and operating substantially in the manner and for the purposes here-
in before described and shown on the accompanying sheet of drawings.
2. In window roller blind furniture of the pawl and ratchet type constructing
the pawl with a double head or duplex engaging surfaces conforming to the shape
shown in the drawings and thus rendering it interchangeable for its due engage-
ment with the ratchet wheel whether the blind roller upon which it is mounted be
made to turn in the one direction or the other and operating substantially in the
manner and for the purposes hereinbefore described and shown on the accompany-
ing sheet of drawings.
3. In window roller blind furniture of the pawl and ratchet type constructing
the pawl with a heel extension which when the pawl falls by gravity a certain
distance by means of its pivotal suspension comes against the rim or wall of the
box and is thereby prevented from assuming the vertical position and operating
substantially in the manner and for the purposes herein before described and
shown on the accompanying sheet of drawings.
4. The general arrangement and combination of parts operating substantially in
the manner as and for the purposes herein before described, and shown on the
accompanying sheet of drawings.
Dofed this 28th day of October 1898.
JOSEPH HENRY PEARSON,
3, Cathkin Avenue, Rutherglen, Applicant's Agent.