AN IMPROVED ÅRRANGEMENT FOR PRODUCING GRADUALLY VARYING ROTARY MOTION BY FRICTIONAL GEARING
Year: 1878

page_text: LETTERS PATENT to James Barbour, of Belfast, in the County of Antrim,
Ireland, for the Invention of "AN IMPROVED ÅRRANGEMENT FOR PRODUCING
GRADUALLY VARYING ROTARY MOTION BY FRICTIONAL GEARING."
Sealed the 23rd August 1878, and dated the 27th February 1878.
PROVISIONAL SPECIFICATION left by the said James Barbour at the Office
of the Commissioners of Patents on the 27th February 1878.
"
JAMES BARBOUR, of Belfast, in the County of Antrim, Ireland. AN IM-
PROVED ARRANGEMENT FOR PRODUCING GRADUALLY VARYING ROTARY MOTION
BY FRICTIONAL GEERING."
This Invention relates to a new arrangement for producing a gradually varying
rotary motion from an uniform one by means of frictional gearing, and consists
generally of two conical-faced dises with one or more driving pullies pressed
between them, the driving and driven axles being parallel.
The two discs are upon the same axle, with their conical faces next one another,
and they are pressed together along this axle by suitable springs, or levers and
weights. Between these conical faced discs, and upon axles parallel thereto, are one
or more belt pullies driven at an uniform speed. These pullies have projecting
conical edges corresponding with the discs, and which are held in contact between
the faces of the conical discs to which they give motion. This motion varies in
speed according to the position of the driving pullies in relation to the centre of the
moveable conical faced discs, for as the belt or driving pullies approach the centre of
the conical faced driven discs the speed of these discs is increased, and as the pullies
are drawn wider apart and the conical faced discs pressed closer together the speed
of the discs is diminished. This contrivance is specially applicable to roving frames
to control the differential motion of the bobbins, and the arrangement is also appli-
cable to a variety of purposes where a gradually varying speed is wanted to be
obtained from an uniform one.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Barbour in the Great Seal Patent Office on the 26th
August 1878.
"
JAMES BARBOUR, of Belfast, in the County of Antrim, Ireland. AN IM-
PROVED ARRANGEMENT FOR PRODUCING GRADUALLY VARYING ROTARY MOTION
BY FRICTIONAL GEARING."
This Invention relates to a new arrangement for producing a gradually varying
rotary motion from an uniform motion by means of frictional gearing, and consists
generally of two conical faced discs with one or more driving pullies pressed between
them, the driving and driven axles being parallel to each other.
The two discs are upon the same axle, with their conical faces inwards, and they
receive a tendency to advance towards each other along this axle by suitable springs,
or levers and weights. This tendency is however resisted by the insertion between
the discs of one or more driving pulleys, by preference two, situate on opposite sides
of the axle of the friction discs. The belt pulleys are mounted on axles parallel to the
axle of the discs, and they are driven at uniform speed. These pulleys have slightly
chamfered edges corresponding with the coned faces of the discs, and they work in
frictional contact therewith, imparting rotary motion to the discs. This motion
varies in speed according to the position of the driving pulleys in relation to the
axis of the friction discs, for as the belt or driving pulleys approach this axis the
speed of the discs is proportionately increased, and as the pulleys are drawn wider
apart and the conical faced discs pressed closer together the speed of the discs is
diminished. This contrivance is specially applicable to roving frames for controlling
the differential motion of the bobbin, and the arrangement is also applicable to a
variety of purposes where a uniform speed is required to be converted into a varying
speed.
In the accompanying Drawing Fig. 1 is a sectional elevation, and Fig. 2 is a
partial plan or top view of the mechanism as applied to a roving frame for flax to
control the motion of the bobbins through the differential wheel to which a gradually.
varying speed is given by the shaft a. On this shaft the friction discs b, b', are so
mounted as to be free to slide thereon to adjust to the inclined friction surfaces of
the driving pullies, as will be presently more fully explained; c, c¹, are the driving
pulleys mounted on stud axles projecting from nuts c³, c, which are carried by and
work upon a right and left hand screwed shaft & having its bearings in the main
framing. These driving pulleys are moved towards or away from the centre of the
discs b, b', (according as the speed of the discs is to be increased or diminished) by
turning the screwed shaft d by means of a crank wheel d' keyed thereon.
The driving pulleys c, c¹, are driven by a belt c from a pulley e on the front
roller of the frame. This belt is kept tight as the driving pulleys c, c³, are
moved out and in by means of a tension pulley f supported by springs on suitable
slides.
The driven discs b, b', are pressed into contact with the edges of the driving
pulleys c, c', by a coiled spring 62 which is between a collar 63 on the socket of the
disc b, and on which the corresponding disc b' is free to slide.
The disc band its socket are free to move endwise over a feather on the shaft a,
and a similar provision is made for the disc b¹ to slide upon the socket of the disc b.
This arrangement allows of the discs 6, 61, adjusting themselves to the varying
positions taken up by the driving pulleys c, c¹, as they are carried out or in by the
right and left hand screw d.
It will now be understood that from an uniform rotary motion of the driving
pulleys e, c, c¹, a rotary motion, varying according to the position of the driving
pulleys c, c', will be given to the driven conical faced discs b, b', the speed of the
discs being increased as the driving pulleys c, c¹, approach their axis, and diminishing
as they recede therefrom.

page_text: Having now set forth the nature of my Invention of "An Improved Arrange-
ment for Producing Gradually Varying Rotary Motions by Frictional Gearing," and
explained the manner of carrying the same into effect, I wish it to be understood
that under the above in part recited Letters Patent I claim the use of a pair of
conical faced gripping discs to which a varying speed is given by a driving pulley
or pulleys pressed between them, the same being arranged on parallel axles, sub-
stantially as and for the purpose above described.
In witness whereof, I, the said James Barbour, have hereunto set my hand
and seal, the Twelfth day of August, in the year of our Lord One thousand
eight hundred and seventy-eight.
JAMES BARBOUR. (L.S.)