A NEW OR IMPROVED METHOD AND APPARATUS FOR GUIDING CHAINS OR ROPES TO WINCH AND OTHER BARRELS
Year: 1883

page_text: LETTERS PATENT to Robert James Rudd of No 1 Uxbridge Terrace Sydenham
Road Croydon in the County of Surrey for an Invention of "A NEW OR
IMPROVED METHOD AND APPARATUS FOR GUIDING CHAINS OR ROPES TO
WINCH AND OTHER BARRELS
"
PROVISIONAL SPECIFICATION left by the said Robert James Rudd at the
Office of the Commissioners of Patents on the 28th July 1883.
ROBERT JAMES RUDD of N° 1 Uxbridge Torrace Sydenham Road Croydon in
the County of Surrey "A NEW OR IMPROVED METHOD AND APPARATUS FOR
GUIDING CHAINS OR ROPES TO WINCH AND OTHER BARRELS
"
In many cases where it is necessary to have barrels of considerable length on
which to wind ropes or chains, the obique direction of the rope or chain as it
winds on to either end of the barrel introduces difficulties causing the successive
convolutions to be too far apart or to be too close together. My invention relates
to means of guiding the rope or chain in such cases, so that there is no tendency
to irregularity in its convolutions on the barrel. For this purpose, I lead the rope
or chain through a hole or eye or over a guido pulley, and then over a second
guide pulley which is arranged to travel in a parabolic curve of which the hole or
eye or the edge of the first guide pulley is the focus, the axis of the barrel being
parallel to the direction. The line of the rope or chain from this second pulley to
the barrel is thus always parallel to the axis of the parabola, the length of the
rope from the barrel to the focus is always the same, and the resultant of strain on
the second guide pulley is always normal to the curve. As an are of a parabola
about its vertex nearly corresponds with a circular arc, it is generally sufficient for
practical purposes to arrange the guide pulley to travel in a circular path, so that
it may be mounted on a radius free to move round a centre.
"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert James Rudd in the Patent Office on the 28th January
1884.
ROBERT JAMES RUDD of N° 1 Uxbridge Terrace, Sydenham Road, Croydon in
the county of Surrey. "A NEW OR IMPROVED METHOD AND APPARATUS FOR
GUIDING CHAINS OR ROPES TO WINCH AND OTHER BARRELS
"
In many cases, where it is necessary to have barrels of considerable length on
which to wind ropes or chains, the oblique direction of the rope or chain as it
winds on to either end of the barrel introduces difficulties causing the successive
convolutions to be too far apart or to be too close together. My invention relates
to means of guiding the rope or chain in such cases, so that there is no tendency
to irregularity in its convolutions on the barrel. For this purpose, I lead the rope
or chain through a hole or eye or over a guide pulley, and then over a second guide
pulley which is arranged to travel in a parabolic curve, of which the hole or eye or
the edge of the first guide pulley is the focus, the axis of the barrel being parallel
to the directrix. The line of the rope or chain from this second pulley to the
barrel is thus always parallel to the axis of the parabola, the length of the rope
from the barrel to the focus is always the same, and the resultant of strain on the
second guide pulley is always normal to the curve. As an arc of a parabola about
its vertex nearly corresponds with a circular arc, it is generally sufficient for
practical purposes to arrange the guido pulley to travel in a circular path, so that
it may be mounted on a radius free to move round-a centre.
Fig. 1 of the accompanying drawings is a diagram explanatory of the principle
on which my invention is founded. DI is the directrix, V the vertex, and F the
focus of a parabola, and P any point in the curve. If BA represent the axis of
a winch or other barrel parallel to the directrix D I, then as F P. is equal to PQ,
FP and PA together make up A Q. Consequently a rope leading from the
focus F over a pulley at P and thence along PA to the barrel, remains of the
same length wherever in the curvo the point P be taken. Moreover, as the normal
to the curve, PS, bisects the angle FPA, and as the strain of the rope in the 3
lines PF and PA are equal, the resultant of these strains coincides with the
normal PS, so that they have no tendency to shift the pulley P along the curve.
When the guido curvo extends only a little way on each side of the vertex, it
nearly coincides with a circular arc struck from a centre C situated at a distance
FC equal to FV; consequently if the guide pulley P be made to travel along
a circular rail V. P. or be carried by a radius C. P, free to move around the centre C,
the result will be practically the same as if it travelled along a true parabola, that
is to say, it will deliver the rope F P A on to the barrel BA, without tending to
make the successive convolutions on the barrel coil on it too near so as to override
each other, or too far apart from each other.
In practically applying this principle for guiding ropes or chains on to barrels,
the position and arrangement of the guiding apparatus must necessarily depend on
the direction in which the rope or chain is led from the object which it lifts or
hauls. In the accompanying drawings I shew arrangements to suit several
different conditions. Fig. 2 is an elevation, and fig 3 a plan of a winch barrel B
with one form of guide. E is a rail bent to the form of a parabola, along which
runs with antifriction rollers DD a carriage for a swivelled pulley C, around
which passes the rope leading to the barrel B. Anywhere in the arc of a parabola
FK J, may be fixed guide pulleys K. by which the rope is led to C. For the
parabolic rail E may be substituted a radius M carrying the guide pulley C, as i

page_text: shown in elevation in fig 4 and in plan in fig 5. The focus F, in this caso, is
midway of the radius M when in its middle position. The radius may be in an
oblique attitude, as shewn in elevation in fig. 6 and in plan in fig. 7, having at its
end a spherical pivot D inserted in the socket of an adjustable plate E, this giving
freedom of motion in the vertical plane, so that the radius D C can adjust itself to
the line of resultant of the strains. When greater steadiness of the radius is
required, it may be made as an open frame fixed on a rocking shaft as shewn in
side view at fig 8 and in front view at fig 9. As the rocking shaft R is fixed in
position it is convenient, for the purpose of adjusting it in the first instance,
to provide sight holes F through the limbs of the radial frame, so that, in fixing
the bearings of the rocking shaft R, the pulley K guiding the rope to C can be
seen through both sight holes. Figs 10 and 11 shew how such an arrangement
may be applied for guiding to a barrel B. When this arrangement is used, it is
preferred to counterbalance the radial frame by heavy parts N below the rocking
shaft.
Having thus described the nature of my said invention and in what manner
the same is to be performed, I claim―
Guiding a rope or chain to a winch or other barrel by a guide pulley free to
travel in a parabolic or approximately parabolic path, substantially as and for tho
purpose herein set forth.
In Witness whereof I the said Robert James Rudd have hereunto set my hand
and seal this Twenty Fifth day of January in the year of our Lord, one thousand
eight hundred and eighty-four.