AN IMPROVEMENT IN SUGAR CANE MILLS
Year: 1877

page_text: LETTERS PATENT to William Renny Watson, of the Firm of Mirrlees, Tait,
and Watson, of Glasgow, in the Counties of Lanark and Renfrew, North
Britain, Engineers, for the Invention of "AN IMPROVEMENT IN SUGAR CANE
MILLS."
Sealed the 15th September 1877, and dated the 5th April 1877.
PROVISIONAL SPECIFICATION left by the said William Renny Watson at
the Office of the Commissioners of Patents on the 5th April 1877.
"
WILLIAM RENNY WATSON, of the Firm of Mirrlees, Tait, and Watson, of Glasgow,
in the Counties of Lanark and Renfrew, North Britain, Engineers. AN IMPROVE-
MENT IN SUGAR CANE MILLS."
This Invention which relates to an improvement in sugar cane mills has for its
object to prevent the vibrating, knocking, or "backlash," which occurs between the
teeth of the wheels composing the gearing betwixt the engine and the mill and the
pinions by which the rollers of mills for crushing sugar canes are geared together,
and in lieu thereof to produce at all times a smooth rolling of the teeth of the
pinions upon one another, as well as stronger teeth less liable to fracture than the
straight-toothed pinions or wheels usually employed.
The foregoing objects are attained by forming each tooth of the wheels or pinions
of two helical segments, one of which is a portion of a right-hand helix, the other
a portion of a left-hand helix. These two segments meet at an angle in the centre
line of the breadth of the wheel or pinion, that is to say, they join or intersect each
other at that angle, and by virtue of this angle in cach tooth end motion and lateral
strain are practically prevented.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Williain Renny Watson in the Great Seal Patent Office on the
2nd October 1877.
WILLIAM RENNY WATSON, of the Firm of Mirrlees, Tait, and Watson, of Glasgow,
in the Counties of Lanark and Renfrew, North Britain, Engineers. "AN IMPROVE-
MENT IN SUGAR CANE MILLS."
My said Invention which relates to an improvement in sugar cane mills has for
its object to prevent the vibrating, knocking, or "backlash" which occurs amongst
the teeth of the wheels composing the gearing betwixt the engine and the mill, as
well as the pinions by which the rollers of mills for crushing sugar canes are geared
together, and in lieu thereof to produce at all times a smooth rolling of the teeth of
the wheels and pinions upon one another, as well as stronger teeth less liable to
fracture than the straight-toothed pinions or wheels usually employed.
The foregoing objects are attained by forming cach tooth of the wheels or pinions
of two helical segments, one of which is a portion of a right-hand helix, and the
other a portion of a left-hand helix. These two segments meet at an angle in the
contre line of the breadth of the wheel or pinion, that is to say, they join or intersect
each other at that angle, and by virtue of this angle in each tooth end motion and
lateral strain are practically prevented.
And in order that my said Invention may be properly understood I now proceed
more particularly to set forth the system, mode, or manner in or under which the
same is or may be used or practically carried into effect, reference being had to the
annexed Sheet of Drawings, and to the letters and figures marked thoreon, that is
to say,
Figure 1 is a plan of a sugar cane mill having its wheels and pinions made with
teeth formed according to my Invention.
Figure 2 is a diagram, in which the dotted lines indicate the helices upon which
the contours of the teeth of the wheels are generated.
Figure 3 is a side view of a portion of a wheel with teeth formed according to
my Invention.
Each tooth of the wheels and pinions is formed of two helical segmonts, one of
which is a portion of a right-hand helix and the other a portion of a left-hand
helix, as shown in the diagram, Figure 2, where the right-hand helical curve a is
that from a segment of which one half of the tooth, from c to d, is formed, and in
which tho left-hand helical curve b is that from a segment of which the other half
of the tooth froin d to e is formed. The two helical segments meet at the centre
line of the breadth of the wheel or pinion and form an angle in the centre of the
tooth, as seen at d in Figure 2. Every tooth of a wheel or pinion is formed in like
manner, and the teeth of the wheel or pinion gearing into it are formed with
corresponding helical segments generated in a like manner, and from curves which
will allow of the teeth of the two wheels gearing together. In Figure 1 I have
shewn a mill for crushing sugar canes in which the teeth of the wheels and pinions
composing the transmitting and multiplying gearing A between the engine B and
the mill C, and the pinions by which the rollers of the mill are geared together are
made with teeth formed according to my Invention.
Although I have described wheels made according to my Invention as having
teeth formed of but two segments of helical curves forming one angle, yet it will be
understood without further description that teeth formed of more than two segments
forming more than one angle may be employed without departing from the nature
of my Invention.
Having now described and particularly ascertained the nature of my said
Invention, and the system, mode, or manner in or under which the same is or may
be used or practically carried into effect, I would observe in conclusion that what
I consider to be novel and original, and therefore clain as the Invention secured
to me by the herein-before in part recited Letters Patent is, the improvement in

page_text: sugar cane mills herein-before described and illustrated in the accompanying
Drawing, that is to say, forming each tooth of the gearing, transmitting, reducing,
or multiplying wheels and pinions of the said mills of two or more helical segments,
one or more of which is or are a portion or portions of a right-hand helix or helices,
5 and the other or others a portion or portions of a left-hand helix or helices.
In witness whereof, I, the said William Renny Watson, have hereunto set my
hand and seal, this Twenty-ninth day of September, One thousand eight
hundred and seventy-seven.
WH. RENNY WATSON. (L.S.)