IMPROVEMENTS IN SUGAR CANE MILLS
Year: 1871

page_text: LETTERS PATENT to Duncan Stewart, of the London Road Iron
Works, Glasgow, in the County of Lanark, North Britain, for the
Invention of "IMPROVEMENTS IN SUGAR CANE MILLS."
Sealed the 3rd April 1872, and dated the 4th December 1871.
PROVISIONAL SPECIFICATION left by the said Duncan Stewart at the
Office of the Commissioners of Patents, with his Petition, on the
• 4th December 1871.
I, DUNCAN STEWART, of the London Road Iron Works, Glasgow, in
the County of Lanark, North Britain, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN SUGAR CANE MILLS," to be as
follows, that is to say :-
This Invention has for its objects to render sugar cane mills less liable
to breakage or injury, from careless or irregular, feeding, and to provide
convenient means for adjusting or regulating the pressure of the rolls.
. The Invention consists in holding the rolls in position by improved
appliances capable of yielding on the occurrence of excessive strains
instead of being rigid or unyielding as hitherto.:
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page_text: In carring out the Invention hydraulic rams are arranged to act
directly or through the intervention of levers on the brasses of the roll
journals, and escape valves loaded to correspond to the pressures that are.
not to be exceeded are fitted in connection with such rams, so that on
a strain occurring in excess of such pressure from overfeeding or other
cause, the escape valves, will open, allow water to escape from the ram,
and so permit the rolls to move further apart.
By varying the loads on the escape valves the effective pressures with
which the rolls act can be altered, and the most suitable and efficient
pressures adopted in different cases; thus the pressure on the feed and
megass sides of the mill may be adjusted differently and so as to yield
the best results.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Duncan Stewart in the Great Seal Patent Office
the 3rd June 1872.
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TO ALL TO WHOM THESE PRESENTS SHALL COME, FI, DUNCAN
STEWART, of the London, Road Iron Works, Glasgow, in the County of
Lanark, North Britain, send greeting.
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WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of December, in the year 2
of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did; for Herself, Her heirs and successors,
give and grant unto me, the said Duncan Stewart, Her special licence
that I, the said: Duncan Stewart, my executors, administrators, and
assigns, or such others as I,, the said Duncan, Stewart, my executors,
administrators, and assigns, should at, any time agree with, and no
others, from time to time and at all times thereafter during the term-
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
SUGAR CANE MILLS, upon the condition (amongst others) that I, the
said Duncan Stewart, my executors or administrators, by an instrument
in writing under my, or their or one of their hands and seals, should
particularly describe and ascertain the nature of the said-Invention;.
IT
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page_text: .the
and in what, manner the same was to be performed; and cause
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
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NOW KNOW. YE, that I, the said Duncan Stewart, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and, ascertained in and, by the
following statement in writing, reference being had to the accompanying
Drawings, that is to say:-..
5.My said Invention has for its objects to render sugar cane mills less
liable to breakage or injury from careless or irregular feeding, and to
provide convenient means for adjusting or regulating the pressure of the
rolls..
My Invention consists in holding the rolls in position by improved-
appliances capable of yielding on the occurrence of excessive, strains.
instead of being rigid or unyielding as hitherto.
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In carrying out. the Invention hydraulic rams are arranged to act
directly or through the intervention of levers on the brasses of the roll
journals, and escape valves loaded to correspond to the pressures that are
not to be exceeded are fitted in connection with such rams, so that on a
strain occurring in excess of such pressure from overfeeding or other
cause, the escape valves will open, allow water to escape from the ram,
and so permit the rolls to move. further apart.
By varying the loads; on the escape valves the effective pressures with
which the rolls act can be altered, and the most suitable and efficient
pressures adopted in different cases; thus the pressures on the feed and
niegass sides of the mill' may be adjusted differently and so as to yield
the best results.'
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What are known as hydraulic accumulators may be used for
maintaining a suitable pressure of water in the cylinders of the hydraulic
rams, and the action of, such accumulators will be equivalent to that of
safety valves, as the water will be forced back and the load on the
accumulator raised whenever a strain takes place between the rolls
greater than what corresponds to the load on the accumulators.
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When it is wished to apply different pressures to the feed and megass
sides different accumulators may be used for the respective hydraulic
:

page_text: rams, or the cylinders or the levers in connection may be differently.
proportioned.
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And in order that my said Invention and the manner of performing
the same may be properly understood, I hereunto append a Sheet of
explanatory. Drawings to be herein-after referred to, and representing
three modifications of sugar cane mills as fitted with my improvements.
In these Drawings the same reference numerals are used to mark the
same or like parts wherever they are repeated.
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Figure 1 of the accompanying Drawings is a front elevation, and-
Figure 2 is a sectional side elevation of one modification of my improved
mills.
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The framing consists of two massive cast-iron housings 1, 2, bolted
down upon an equally massive cast-iron bed plate 3. There are three
crushing rolls 4, 5, 6, placed in the relative positions usual in such
mills. The top or middle roll 5. is carried in ordinary bearings 7 in
the tops of the housings 1, 2, the upper brasses being held down by
malleable iron or steel caps 8 and long, bolts 9. The two lower rolls
4, 6, are pressed up towards the upper central roll 5 by brasses 10
fitted so as to be capable of a little movement-in, guide openings formed
for them in the housings, and which openings are closed on the outer
side by cover pieces 11 capable of being removed when getting the rolls
into or out of their places. The brasses 10. are themselves pressed up
by rams 12 working in hydraulic cylinders 13, placed in cavities
formed for them in the housings 1, 2, the cylinders 13 being supplied
by pipes 14 with water or other suitable liquid forced in under a
suitable pressure.
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With this arrangement it will be easily seen that on anything getting
between either of the lower rolls 4, 6, and-the-upper-one-5,-so_as_to_
cause a greater strain than what corresponds-to-the-pressure-of-the
liquid in the cylinders 13, the liquid will be forced back out of the
cylinders by the rams 12, and the roll 4 or 6 will thus be able to
move away from the upper roll 5, and so be relieved of extra strain..
Figure 3 is a sectional side elevation showing how my improved
appliances can be adapted-to-existing sugar cane mills of a common
type. In this example the brasses 10 of the lower rolls 4, 6, slide
on horizontal guides formed in the housings 1, 2, and the ram 12 is
arranged to press them in the horizontal direction. The hydraulic-

page_text: cylinders 13 are formed in castings 15 shaped to fit against the ends of
the housings, and secured thereto in a manner that will be easily under-
stood from the Drawing..
Figure 4 is a side elevation of a modification of my improved sugar
cane mills in which the hydraulic rams 12 are arranged to act through
strong levers 16. The hydraulic cylinders 13 are formed in or fixed
to the base plate 3, and the levers 16 act on rods 17, which working
through guide holes formed in the housings bear against the brasses 10
of the lower rolls 4, 6.
Having thus particularly described my said Invention, and the manner
in which the same is or may be performed, I have to state that I
do not restrict myself to the precise details herein described or
delineated; but that what I believe to be novel and original, and claim
as the Invention secured to me by the herein-before in part recited
Letters Patent is, the constructing of sugar cane mills with hydraulic
rams arranged to act directly or through the intervention of levers
on the brasses of the roll journals substantially as and for the purposes
herein-before described.
In witness whereof, I, the said Duncan Stewart, have hereunto
set my hand and seal, this Thirteenth day of May, in the year
of our Lord One thousand eight hundred and seventy-two.
DUNCAN STEWART. (L.S:)