IMPROVEMENTS IN RACK PULLEYS FOR THE CORDS OF WINDOW BLINDS, MAPS, AND OTHER ARTICLES
Year: 1877

page_text: LETTERS PATENT to Frederic Arthur Harrison, of Birmingham, in the County
of Warwick, Manufacturer, and Charles Priestland, of Birmingham, aforesaid,
Tool Maker, for the Invention of "IMPROVEMENTS IN RACK PULLEYS FOR THE
CORDS OF WINDOW BLINDS, MAPS, AND OTHER ARTICLES."
Sealed the 17th April 1877, and dated the 19th January 1877.
PROVISIONAL SPECIFICATION left by the said Frederic Arthur Harrison
and Charles Priestland at the Office of the Commissioners of Patents on the
19th January 1877.
FREDERIC ARTHUR HARRISON, of Birmingham, in the County of Warwick,
Manufacturer, and CHARLES PRIESTLAND, of Birmingham, aforesaid, Tool Maker.
IMPROVEMENTS IN RACK PULLEYS FOR THE CORDS OF WINDOW BLINDS, MAPS,
AND OTHER ARTICLES."
"
Our Invention consists of the construction and arrangement of the parts of rack
pulleys, herein-after described, whereby great simplicity in construction is secured,
together with advantages in use not possessed by the ordinary rack pulley. We
dispense with the ordinary rack teeth, and in place thereof we make in the front
of the pulley frame, which is fixed to the window frame or other fixed part, a slot
of a length equal to the range of motion which it is intended the pulley under
which the blind or other cord passes shall have. A series of equidistant notches is
made on the edges of this slot, each notch on one side being exactly opposite a
notch on the other side, that is, the said notches are in pairs. A strip of sheet
metal, somewhat broader than the slot, is doubled or folded at its middle so as to
bring its ends into contact, the said middle part where the bend is made being
narrower than the other parts of the strip so that the folded or doubled strip can
be engaged with the slot with one balf on one side and the other half on the other
side of the frame in which the slot is formed, and as it grips the edges of the slot
can be brought by a sliding motion to any part of the slot. We will herein-after
call this part the pulley carrier. The inner part of the said pulley carrier has at
its bottom a tooth formed by bending its lower tapering end at right angles. The
Din 71

page_text: said tooth is of a size and form proper to engage in any of the pairs of notches in
the slot. The axis of the pulley passes through a slot in the front part of the
pulley carrier, and is fixed in the back part. The front end of the axis of the
pulley terminates in a thumb plate.
In engaging the pulley carrier with the notched slot in the frame it is necessary
to press upon the thumb plate, the tooth is thereby depressed and the slide can be
brought to any position in the slot. When the thumb plate is no longer pressed a
slight upward or downward motion brings the tooth opposite one of the pairs of
notches, and the tooth springs into the said notches and fixes the pulley carrier.
In order to raise or lower the pulley carrier it is only necessary to press on the
thumb plate, when the tooth is depressed from out the notches and the slide can be
raised or lowered, the tooth engaging in any pair of notches it may be brought
opposite to by ceasing to press the thumb plate.
The pulley carrier may be modified in the following manner :-The middle part
constituting the bend may be of the same width as the other part, and both parts
of the pulley carrier pass under the edges of the slot in the frame. The axis of the
pulley is fixed to the front part of the pulley carrier, and the tooth which engages
in the notches is formed at the bottom of the front part of the pulley carrier. In
the first-described arrangement the two parts of the pulley carrier spring towards
each other; in the modification described they spring apart.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frederic Arthur Harrison and Charles Priestland in the Great
Seal Patent Office on the 5th July 1877.
FREDERIC ARTHUR HARRISON, of Birmingham, in the County of Warwick,
Manufacturer, and CHARLES PRIESTLAND, of Birmingham, aforesaid, Tool Maker.
"IMPROVEMENTS IN RACK PULLEYS FOR THE CORDS OF WINDOW BLINDS, MAPS,
AND OTHER ARTICLES."
Our Invention consists of the construction and arrangement of the parts of rack
pulleys, herein-after described, whereby great simplicity in construction is secured,
together with advantages in use not possessed by the ordinary rack pulley. We
dispense with the ordinary rack teeth, and in place thereof we make in the front of
the pulley frame, which is fixed to the window frame or other fixed part, a slot of
a length equal to the range of motion which it is intended the pulley under which
the blind or other cord passes shall have. A series of equidistant notches is made
on the edges of this slot, each notch on one side being exactly opposite a notch on
the other side, that is, the said notches are in pairs. A strip of sheet metal, some-
what broader than the slot, is doubled or folded at its middle so as to bring its ends
into contact, the said middle part where the bend is made being narrower than the
other parts of the strip so that the folded or doubled strip can be engaged with
the slot with one half on one side and the other half on the other side of the frame
in which the slot is formed, and as it grips the edges of the slot can be brought by
a sliding motion to any part of the slot. We will herein-after call this part the
pulley carrier. The inner part of the said pulley carrier has at its bottom a tooth
formed by bending its lower tapering end at right angles. The said tooth is of a
size and form proper to engage in any of the pairs of notches in the slot. The axis
of the pulley passes through a slot in the front part of the pulley carrier and is
fixed in the back part. The front end of the axis of the pulley terminates in a
thumb plate.
In engaging the pulley carrier with the notched slot in the frame it is necessary
to press upon the thumb plate, the tooth is thereby depressed and the slide can be
brought to any position in the slot. When the thumb plate is no longer pressed a

page_text: slight upward or downward motion brings the tooth opposite one of the pairs of
notches, and the tooth springs into the said notches and fixes the pulley carrier.
In order to raise or lower the pulley carrier it is only necessary to press on the
thumb plate, when the tooth is depressed from out the notches and the slide can be
raised or lowered, the tooth engaging in any pair of notches it may be brought
opposite to by ceasing to press the thumb plate.
The pulley carrier may be modified in the following manner:-The middle part
constituting the bend may be of the same width as the other part, and both parts
of the pulley carrier pass under the edges of the slot in the frame. The axis of the
pulley is fixed to the front part of the pulley carrier, and the tooth which engages
in the notches is formed at the bottom of the front part of the pulley carrier. In
the first-described arrangement the two parts of the pulley carrier spring towards
each other; in the modification described they spring apart.
We will now proceed to describe, with reference to the accompanying Drawings,
the manner in which our Invention may be performed.
Figure 1 represents in front elevation; Figure 2, in side elevation; and Figure 3,
in longitudinal section a rack pulley constructed according to one of the arrange-
ments of our Invention; Figure 4 represents the same view as Figure 3, with the
pulley carrier released from the notched slot for adjusting the said pulley carrier;
Figure 5 is a cross section of Figure 3 taken on the line A, A; and Figure 6 is a
cross section of Figure 4 taken on the line B, B.
Figure 7 represents the stamped blank from which the frame of the rack pulley
is made; and Figure 8 represents the same after the notched slot has been pierced
in its front plate.
Figure 9 represents the combined pulley carrier, pulley and finger plate detached
from the frame; Figure 10 represents the blank from which the pulley carrier is
made; and Figure 11 represents the pulley carrier made from the blank, Figure 10.
The same letters indicate the same parts in Figures 1 to 10.
a is the pulley frame fixed to the window frame or other fixed part; b is the
slot in the front plate of the pulley frame a, the said slot being closed at top and open
at its bottom 62. On the edges of the said slot ba series of pairs of equidistant
notches marked c, c, is made. The pulley carrier which works in the said notched
slot b, c, consists of a double strip of sheet metal somewhat broader than the slot b.
The two doubled or parallel parts of the pulley carrier are marked respectively e, f,
and the said parts e, f, are made by doubling the pierced blank q, Figure 10, at its
middle, as illustrated in Figure 11. The bend or junction e² of the two nearly
parallel parts e, f, of the pulley carrier is narrower than the other parts, the said
bend e being of a width proper to slide without obstruction in the slot b of the
pulley frame. The part of the pulley carrier is a little wider than the other
part e. The pulley carrier e, f, thus made can be introduced at the open bottom b²
of the slot b into the said slot b, and when so introduced one half of the pulley
carrier is situated underneath the notched front of the pulley frame a, and the
other half e is situated outside the said notched front of the pulley frame, the two
parts e, f, of the pulley carrier clipping the opposite sides of the notched plate of
the frame in the manner best seen in the cross section, Figure 5. The inner part f
of the pulley carrier, which said part f constitutes the spring tongue of the said
carrier, has at its lower end a tooth f2, the said tooth being made by bending the
end of the blank, Figure 10, at right angles. This tooth f2 is of a size and figure
proper to engage in any of the pairs of notches c, c, in the slot b; g is the pulley
under which the blind or other cord passes, and h is the axis of the said pulley,
the inner end of the said axis being rivetted to the inner or tongue part ƒ of the
pulley carrier. The front end of the pulley axis his rivetted to a thumb plate i.
The axis h passes through a slot in the front part e of the pulley carrier. By
pressure in a downward direction upon the thumb plate i the inner or tongue
part of the pulley carrier may be separated or opened from the outer part e, which
said outer part is capable only of a sliding motion with the other parts of the pulley
carrier.

page_text: In engaging the pulley carrier e, f, with the notched slot b, c, of the pulley frame
the narrow or bent end e² is introduced into the slot through the open bottom b²,
and the lower end of the thumb plate i is pressed upon so as to force back the
tooth f. The pulley carrier can now be passed into the slot b by a sliding motion
(the two parts e, f, of the said pulley carrier engaging on opposite sides of the
notched front plate of the pulley frame) and moved to any position in the said slot.
On removing the pressure from the thumb plate i the spring tongue ftakes the
position, Figure 3, and its tooth f2 springs into one of the pairs of notches c, c, in
the pulley frame opposite which the said tooth has been brought and the said pulley
carrier is fixed.
In order to adjust the pulley carrier for tightening or slackening the blind or
other cord it is only necessary to press on the lower end of the thumb plate i when
the spring tongue or inner part fis pressed towards the open back of the pulley
frame and the tooth f2 on its end depressed from out the notches c, c, as illustrated
in Figures 4 and 6, and the pulley carrier is released and may be raised or lowered
in the pulley frame to the desired extent. On relaxing the pressure on the thumb
plate the tooth f2 engages itself with the pair of notches c, c, opposite which it has
been brought and the pulley carrier is again fixed in its adjusted position. The
inner part or spring tongue f of the pulley carrier works closely against the sides
of the pulley frame a, the said sides acting as guides to the pulley carrier in its
motion in the pulley frame.
Figure 12 represents in front elevation; Figure 13, in side elevation; and
Figure 14, in longitudinal section another arrangement of our Invention; Figure 15
represents the same view as Figure 14 with the pulley carrier released; Figure 16
is a cross section of Figure 14; and Figure 17 is a cross section of Figure 15.
Figure 18 is a side elevation; and Figure 19, a front elevation (portions being
removed) of the pulley carrier, pulley, and thumb plate.
Figures 20, 21, 22, and 23 illustrate the manner in which the pulley frame is
made from a flat blank.
In this arrangement both the doubled parts of the pulley carrier work inside the
open ended pulley frame m, the back of the said pulley frame being closed and
serving as a bearing for one of the parts of the pulley carrier. The front plate of
the pulley frame has a notched slot b, c, as before described. The front part f of
the pulley carrier in this arrangement constitutes the spring tongue, and has at its
end a tooth f2, and the axis h of the cord pulley g is rivetted to the said front
part f. The back part e of this pulley carrier bears against the back plate m² of
the pulley frame, the said part e working closely against the sides of the said pulley
frame, as seen in the cross sections, Figures 16 and 17. When the thumb plate i
is pressed upon, the front part or tongue f, carrying the tooth f2, is pressed towards
the back part e, the tooth f2 is thereby depressed out of the notches c, c, and the
pulley carrier is released and may be adjusted in the pulley frame, as herein-before
particularly described with respect to the first-described arrangement.
The pulley frame m is made from the blank, Figure 20, the said blank having
notched edges. The sides of the notched blank are first raised at right angles to
the back part, as illustrated in Figure 22, the partly made frame is next bent into
the form represented in Figure 23, and finally into the form represented in
Figure 21.
Having now described the nature of our Invention, and the manner in which the
sume is to be performed, we wish it to be understood that we do not limit ourselves to
the precise details herein described and illustrated, as the same may be varied
without departing from the nature of our Invention; but we claim as our Invention,
the improvements in rack pulleys for the cords of window blinds, maps, and other
articles, herein-before described and illustrated in the accompanying Drawings, that
is to say, making on the edges of the slot in the pulley frame in which the pulley
carrier works a series of equidistant pairs of notches, each notch on one side of the
slot being exactly opposite a notch on the other side of the slot, and the combination

page_text: with the said notched slot in the pulley frame of a pulley carrier constructed and
working in the pulley frame, substantially in the ways described and illustrated.
In witness whereof, we, the said Frederic Arthur Harrison and Charles
Priestland, have hereunto set our hands and seals, this Second day of July,
in the year of our Lord One thousand eight hundred and seventy-seven.
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
FREDERIC ARTHUR HARRISON. (L.S.)
CHARLES PRIESTLAND.
(L.S.)
Birmingham.