IMPROVEMENTS IN THE CONSTRUCTION OF RACKS AND PULLEYS FOR WINDOW BLINDS AND OTHER USEFUL PURPOSES
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
-DOBBS, of the Penn Road, Wolverhampton, in the County of Stafford, Brass
Founder, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminister, the Thirtieth day of June, in the second year of Her reign, in
the year of our Lord One thousand eight hundred and thirty-eight, did, for
Herself, Her heirs and successors, give and grant unto me, the said William
Dobbs, Her especial licence, full power, sole privilege and authority, that I,
the said William Dobbs, my executors, administrators, and assigns, and such
others as I, the said William Dobbs, my executors, administrators; and
assigns, and such others as I, the said William Dobbs, my executors, admi-
nistrators, or assigns, should at any time agree with, and no others, from
time to time and at all times during them of years therein mentioned,
should and lawfully might make, use, exercise, and vend, with England,
CERTAIN
Wales, and the Town of Berwick-upon-Tweed, my Invention of
IMPROVEMENTS IN THE CONSTRUCTION OF RACKS AND PULLEYS FOR WINDOW
BLINDS AND OTHER USEFUL PURPOSES;" in which said Letters Patent is con

page_text: tained a proviso obliging me, the said William Dobbs, by an instrument in
writing under my hand and seal, particularly to describe and ascertain the
nature of my said Invention, and the manner in which the same is to be
performed, and to cause the same to be inrolled in Her Majesty's High Court
of Chancery within six calendar months next and immediately after the date
of the said in part recited Letters Patent, as in and by the same, reference
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Dobbs, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are particularly described
and ascertained in and by the following description thereof, reference being
had to the. Drawings hereunto annexed, and to the letters and figures marked
thereon (that is to say):-
My improvements in the construction of what are called rack pullies for
giving tension to the cords of roller window blinds consist in a novel mode of
manufacturing the boxes, cases, or frames in or upon which the tension pulley
slides, and also in a method of confining the pulley in the box, case, or frame,
by means of a screw when the cord has been drawn to its required tension.
In preparing the racks for the pullies, that is, the boxes, cases, or frames, in
or upon which the pulley is to slide, instead of casting from molten metal
these boxes, cases, or frames in the required form, or of bending up the
edges of plates by hammering in the manner which has been heretofore com-
monly practised, I produce the boxes, cases, or frames from flat thin sheet
metal by the operation of drawing, in a manner nearly resembling that in
which metal tubes are finished at a drawbench. I first cut out from a thin
plate or sheet, by means of shears or otherwise, suitable strips of flat metal,
and, after slightly bending up the end of each strip, pass it, as at A in the
accompanying Drawing, Fig. 1, through a hollow frustrum of a cone shewn
at B. As the strip proceeds through the hollow cone, its edges are gradually
bent inwards, and after passing the smaller end of the cone and through
a suitable hole in the steel plate C, shewn detached in front view at Fig, 2,
the strip comes out in a partial tubular shape, as at D. When this has been
slipped on to a steel
done the tube must be annealed and scoured, and then
rod or mandril E of the form in which the box, case, or frame is desired to
be made, which rod and tube together are to be passed into a properly shaped
hole in another steel plate (a front view of which is shewn at f, Fig. 3). This
plate is then placed on a drawbench, and the end of the rod and tube E taken
hold of by a pair of suitable pliers G shew at Fig. 4. On a sufficient force

page_text: being applied by a draw chain to the handles of the pliers, the rod and tube
is drawn through the plate and delivered on the opposite side, as at H, in
the finished shape required. The open tube thus prepared is then to be
slipped off the rod or mandril and cut up into suitable lengths for constituting
several rack frames, boxes, or cases for the sliders of the tension pullies to act
in or upon, and their ends may be trimmed, shaped, and stamped as usual,
and made to appear as at Fig. 5. If spring pullies, as shewn in the section at
a, Fig. 6, should be required to act in these boxes, they may each have a series
of ratchet teeth 6 formed up the middle of the back plate by means of a
rolling indented die, or by any other ordinary or convenient apparatus; but I
prefer leaving the back plain, and adapting, instead of the spring catch, my
improved screw fastening in the manner about to be explained.
Fig. 7 represents sectional views of Fig. 5. C, C, in each of these Figures
shews the front edges or flanges of the box, case, or frame. d is the tension
pulley fitted loosely upon a stud e, e, which stud is screwed into a block,
clamp, or sliding plate f behind the flanges of the box. When the pulley has
been drawn down sufficiently far to put the cord g of the roller blind in proper
tension the knob or rose head of the stud e is to be turned so as to draw up
by means of its screw the block, clamp, or plate f tight against the back part
of the flanges, which will cause the clamp and stud of the pulley to remain
firmly fixed in their position in the frame, and thereby retain the pulley or
tension; but it may be readily released, and the tension of the cord relaxed,
by turning the screw stud e in the opposite direction..
Having now described my Invention, and the manner of carrying the same
into effect, I desire it to be understood that I do not intend to confine myself
to any particular forms of boxes, cases, or frames for supporting the tension
pullies for roller blinds, but I claim the making of such boxes, cases, or frames
by means of drawing strips of thin metal through a cone and through a draw
plate in the manner in which metallic tubes are usually finished, and also
the adaptation of tubes so made as boxes, cases, or frames for the sliders of
bell pulls and other useful purposes; and I further claim the contrivance
for fixing the stud of the pulley by means of a clamp and screw, as above
described.
In witness whereof, I, the said William Dobbs, have hereunto set my
hand and seal, this Twenty-eighth day of December, in the year of
our Lord One thousand eight hundred and thirty-eight.
WILLIAM (L.s.) DOBBS.

page_text: AND BE IT REMEMBERED, that on the Twenty-eighth day of Decém-
ber, in the second year of the reign of Her Majesty Queen Victoria, the said
William Dobbs came before our said Lady the Queen in Her Chancery,
and acknowledged the Instrument aforesaid, and all and every thing therein
contained and specified, in form above written. And also the Instrument
aforesaid was stamped according to the tenor of the Statute: made in the
fifty-fifth year of the reign of His late Majesty King George the Third.
Inrolled the Twenty-ninth day of December, One thousand eight hundred