IMPROVEMENTS IN SUGAR CANE MILLS
Year: 1881

page_text: LETTERS PATENT to Duncan Stewart, of the London Road Iron Works,
Glasgow, in the County of Lanark, North Britain, for an Invention of
"IMPROVEMENTS IN SUGAR CANE MILLS."
PROVISIONAL SPECIFICATION left by the said Duncan Stewart at the
Office of the Commissioners of Patents on the 17th August 1881.
DUNCAN STEWART, of the London Road Iron Works, Glasgow, in the County of
Lanark, North Britain. "IMPROVEMENTS IN SUGAR CANE MILLS."
This Invention relates to sugar cane mills of the kind in which hydraulic
apparatus is used for applying pressure to the rolls, the parts yielding on the
occurrence of excessive strains, and the mills being thereby rendered less liable to
breakage or injury from careless or irregular feeding.
The mill as made according to the present Invention is of the three roller class,
and the bearing caps of the upper or middle roll are held down in the usual way,
but the two lower rolls are pressed horizontally inwards by the rams of hydraulic
cylinders, these rams acting on the bearing blocks which are fitted on horizontal
guide beds. The hydraulic cylinders are held in their places by caps or crossheads
which are fixed by screw nuts on long rods or bolts passing completely through the
housings or headstocks, a pair of such rods or bolts, one above and the other below
the bearing, serving for the two lower bearings in each housing. The hydraulic
cylinders are supplied with water or other suitable liquid under pressure from one
or more accumulators loaded to a suitable pressure or pressures; or the rams may
be held, the cylinders being movable and pressing on the bearing blocks. When
strains occur corresponding to a greater pressure than that for which the
accumulator is loaded, the rams or cylinders yield and breakage is avoided; and
to give a still greater elasticity of action and sensitiveness air vessels are fitted in
connection with the hydraulic cylinders.
A further improvement comprised in the present Invention consists in con-
necting what is known as the returner to the bearing blocks of one of the lower
rolls by means of links jointed to the ends of the returner and to half rings passing
partly round the roll journals and fixed. to the bearing blocks. With these
improved arrangements the scraping edge of the return is kept properly in
contact with the surface of the roll, and the parts are not liable to rapidly wear
loose.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Duncan Stewart in the Great Seal Patent Office on the 15th February
1882.
DUNCAN STEWART, of the London Road Iron Works, Glasgow, in the County of
Lanark, North Britain, "IMPROVEMENTS IN SUGAR CANE MILLS."
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 formerly. I
apply my Invention to a mill of the well known three-roller class, the bearing caps
of the upper or middle roll being held down in the usual way, whilst the two lower
rolls are pressed horizontally inwards by the rams of hydraulic cylinders, the rams
acting on the bearing blocks which are fitted on horizontal guide beds. The
hydraulic cylinders are held in their places by rods or long bolts passing hori-
zontally and completely through the housings or headstocks, a pair of such rods or
long bolts, one above and the other below the bearing, serving for the two lower
bearings in each housing. The hydraulic cylinders are supplied with water or
other suitable liquid under pressure from an accumulator loaded to a suitable
pressure. When strains occur corresponding to a greater pressure than that for
which the accumulator is loaded, the rams yield and breakage is avoided; and to
give a still greater elasticity of action and sensitiveness air vessels are fitted in
connection with the hydraulic cylinders. The lower rolls being thus liable to
horizontal movement, it is necessary to provide means to keep the edge of what is
known as the "returner" in contact with that one of the lower rolls, between
which and the middle roll the canes are first passed; for this purpose the ends of
the returner have adjustably fixed to them links or bars which are curved to pass
without frictional contact over the journals of the roll, and are attached to the
bearing blocks so that the returner moves with the blocks, and in consequence its
edge keeps close to the roll.
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 hereinafter referred to, and representing a sugar-cane mill as constructed
or fitted with my improvements.
In the accompanying Drawings, Figure 1 is a sectional end elevation; and
Figure 2 is a side elevation. Figures 3 and 4 are vertical and horizontal sections
explanatory of the returner details. In these Drawings the same reference
numerals are used to mark the same or like parts wherever they are repeated.
The framing consists as usual of a pair of massive housings or headstocks 5 fixed
on a bed plate 6, and it carries three rolls 7, 8, 9, the middle one 8 being partly
between and partly above the other two which are at the same level; the upper
or middle roll 8 is held in ordinary bearings, the caps 10 of which are held down
in the usual way; the lower rolls 7, 9, are held on bearing blocks 11 which are
fitted to slide on horizontal guide beds 12, and which are pressed inwards by the
rams 13 of hydraulic cylinders 14; these cylinders 14 are formed with collars or
lugs 15 by means of which they are fixed to the framing, and they are securely
held by nuts 16 screwed on the ends of horizontal rods or long bolts 17 passing
completely through the housings 5 and through the lugs 15, and transmitting the
horizontal strains between the opposite cylinders. The cylinders 14 are supplied
with water or other suitable liquid under pressure by branch pipes 18 leading it
from a suitably loaded accumulator, and near each cylinder there is connected to
•

page_text: its pipe an air vessel 19, the air in which renders the relieving action quicker
when sudden strains occur.
The returner 20 which guides the canes round under the middle roller 8 rests,
and is movable on the upper horizontal surface of a bearer 21 fixed in openings in
the housings 5, and the returner is made with ends 22 which project through the
same openings and which have curved bars or links 23 attached to them; these
links 23 are curved to pass without frictional contact over the roller journals 24,
and they are formed with eyes at their outer ends to be set on studs or projecting
pins formed on the bearing blocks 11, or on the heads of the rams 13 which bear
against the blocks 11. The inner ends of the links 23 are screwed and passed
through holes in the returner ends 22 to which they are adjustably fixed by screw
nuts at each side.
Having thus particularly described my said Invention, and the manner of
performing the same, 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 and in terms of the
herein before in part recited Letters Patent is,―
1. The combination of air vessels with hydraulic cylinders by which pressure is
applied to the lower rolls of sugar-cane mills, substantially as and for the purposes
set forth.
2. The combination of rods or long bolts with hydraulic cylinders by which
pressure is applied to the lower rolls, the said rods or long bolts passing through
the housings and connecting the cylinders at opposite parts thereof, substantially as
and for the purposes set forth.
3. The adjustable links connecting the ends of the returner to the horizontally
movable bearing blocks on the entering side, the said links being curved to avoid
frictional contact with the roller journals.
In witness whereof, I, the said Duncan Stewart, have hereunto set my hand
and seal, this Fourteenth day of February, in the year of our Lord One
thousand eight hundred and eighty-two.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
DUNCAN STEWART. (L.S.)