IMPROVEMENTS IN APPARATUS FOR HOISTING, LOWERING, PULLING, AND RETAINING AT ANY DESIRED POINT WEIGHTS OR BODIES, PART OF WHICH INVENTION IS APPLICABLE TO DRIVING MACHINERY
Year: 1874

page_text: LETTERS PATENT to Martyn John Roberts, of the City of Bath,
Esquire, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
HOISTING, LOWERING, PULLING, AND RETAINING AT ANY DESIRED POINT
WEIGHTS OR BODIES, PART OF WHICH INVENTION IS APPLICABLE TO DRIVING
MACHINERY."
Sealed the 30th April 1875, and dated the 2nd November 1874.
PROVISIONAL SPECIFICATION left by the said Martyn John Roberts
at the Office of the Commissioners of Patents, with his Petition,
on the 2nd November 1874.
I, MARTYN JOHN ROBERTS, of the City of Bath, Esquire, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN APPARATUS
FOR HOISTING, LOWERING, PULLING, AND RETAINING AT ANY DESIRED POINT
WEIGHTS OR BODIES, PART OF WHICH INVENTION IS APPLICABLE TO DRIVING
MACHINERY," to be as follows:-
The chief objects of my Invention are to allow weights or bodies
which are being raised, lowered, or pulled to be retained at any desired
point by means of differential pulleys, or of ordinary pulleys, or other

page_text: like devices provided with breaks; also to allow of cords or bands being
used in lieu of chains in differential pulleys. And the Invention consists
in fixing an elastic bed upon the pulleys or other like devices combined
with means for compressing or tightening upon the pulleys the cords or
bands which run thereon; the said means may be a spring, or a weight,
or a presser acting upon such cords or bands. Or in combination with
the elastic bed on the main pulley I employ a subsidiary pulley over
which I carry the cord, and I cause this pulley to revolve at a different
velocity to the main pulley, over which the cord is also carried, and I
thus tighten the cord on the main pulley. Or in combination with the
elastic bed on the main pulley I use what I term a "clasp guide," con-
sisting of a pulley or guide, over which I carry the cord, the said guide
being in such position as to cause the cord to embrace a greater portion
of the circumference of the main pulley than if no such guide were
used.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Martyn John Roberts in the Great Seal Patent
Office on the 1st May 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARTYN 2
JOHN ROBERTS, of the City of Bath, Esquire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of November, in the year
of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and succes- 3
sors, give and grant unto me, the said Martyn John Roberts, Her
special licence, that I, the said Martyn John Roberts, my executors,
administrators, and assigns, or such others as I, the said Martyn John
Roberts, my executors, administrators, and assigns, should at any time

page_text: 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 APPARATUS FOR HOISTING, LOWERING, PULLING, AND RETAINING
AT ANY DESIRED POINT WEIGHTS OR BODIES, PART OF WHICH INVENTION IS
APPLICABLE TO DRIVING MACHINERY," upon the condition (amongst others)
that I, the said Martyn John Roberts, 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, and in what manner the same was to be performed, and cause
the 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.
NOW KNOW YE, that I, the said Martyn John Roberts, 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 thereof, reference being had to the
accompanying Drawings, that is to say -
The chief objects of my Invention are to allow weights or bodies which
are being raised, lowered, or pulled to be retained at any desired point
by means of differential pulleys, or of ordinary pulleys, or other like
devices provided with breaks; also to allow of cords or bands being used
in lieu of chains in differential pulleys. And the Invention consists in
fixing an elastic bed upon the pulleys or other like devices combined
with means for compressing or tightening upon the pulleys the cords or
bands which run thereon; the said means may be a presser, or a weight,
or a spring acting upon such cords or bands.
One manner in which my Invention may be carried into effect when a
presser is used to compress or tighten the cord or band upon the pulley
is represented in Figures 1 and 2 of the annexed Drawings. A is the
pulley or sheave over which the rope B which suspends the load C runs;
the periphery of this pulley is covered with india-rubber a or other
substance which will form an elastic bed for the rope; D is a lever or
rod having its fulcrum at E; one end F of this lever is weighted, while
the other end. presses against the rope at a convenient part of the circum-
ference of the pulley A and thus prevents the rope slipping over the
pulley; in order to reduce any friction that may arise between the

page_text: lever D and the rope while the pulley is revolving I sometimes attach a
small roller G to the rod, which roller works upon the rope.
It will be readily understood that if the pulley A. be prevented
revolving by a break or otherwise the rope B will be prevented slipping
upon the pulley by the means described, and the weight or load C
suspended to the rope can therefore be retained at any desired point. I
do not limit myself to the mode of pressing represented in the Drawing,
for a spring or other device may be employed.
One manner in which my Invention may be carried into effect when
a weight is employed to tighten the rope on the pulley is represented in 1
Figures 3 and 4 as applied to a differential pulley. A, 'A', is the
differential pulley, the periphery of which is covered with india-rubber
a, a¹, so as to form an elastic bed for the rope B. H is the usual block
round which the rope passes at the lower part of its travel, and to this
block the hook O for the load to be lifted or lowered is fixed; I is a 1
" of
weight applied by means of a small wheel or pulley K to the "fall
the rope. The weight I and the load attached to the hook C so tighten
the rope as to prevent it slipping on the pulley A, A', and I am thus
enabled to use ropes or cords in lieu of chains in differential pulleys.
In some cases instead of employing a presser, a spring, or a weight, as ?
herein-before described, to compress or tighten the rope upon the clastic
bed I lead the rope after it has passed over the (main) pulley over a
supplementary pulley, and I cause this pulley to revolve somewhat
faster than the main pulley, whereby I produce a friction and pulling
action upon the rope and thus tighten it on the elastic bed of the main
pulley.
In some cases also in order to prevent the rope slipping over the
pulley I use what I term a "clasp guide" or "clasp pulley," consisting
of a pulley or guide over which I carry the rope, the said guide being in
such position as to cause the rope to embrace a greater portion of the
circumference of the main pulley than it would do if no such guide
were used. This mode will be understood on reference to Figure 5.
A is the main pulley, the periphery of which is furnished with an elastic
bed. Lis the clasp pulley, placed at such a position, as shewn, that the
B is caused to embrace a large portion of the pulley A.
rope
In some cases instead of pressing the rope upon the elastic bed of
the pulley, as before described, I cause the "fall" of the rope to pass

page_text: between two pressers or beds, one or both of which are elastic, and I
thus prevent the rope slipping on the pulley.
By the adoption of any of the modes herein-before described I prevent
a rope slipping upon its pulley or sheave when the latter is at rest, or I
cause the rope to travel at the same speed as the main pulley, whereby
I am enabled in the first case to retain a load or weight at any desired
point, and in the second case to properly drive a pulley or sheave from
another pulley or sheave:
""
The "clasp guide or clasp pulley," as also the presser roller or
pulley, and the speeded pulley, herein-before described, in combination
with an elastic bed on the periphery of a pulley or drum, are also
applicable to driving machinery.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim,-
First. Constructing apparatus for hoisting, lowering, pulling, and
retaining at any desired point weights or bodies, as herein-before
described.
Second. The employment in apparatus for hoisting, lowering, pulling,
or retaining at any desired point weights or bodies of a pulley or like
device with an elastic bed in combination with a presser, a spring, or a
weight for compressing or tightening the cord or band on the pulley,
substantially as herein-before described.
Third. The employment in apparatus for hoisting, lowering, pulling,
or retaining at any desired point weights or bodies of a pulley or like
device with an elastic bed in combination with a supplementary pulley
driven at a quicker speed so as to tighten the cord or band on the main
pulley, substantially as herein-before described.
Fourth. The employment in apparatus for hoisting, lowering, pulling,
or retaining at any desired point weights or bodies of a pulley or like
device with an elastic bed in combination with a clasp pulley or a clasp
guide, substantially as herein-before described.
Fifth. The employment in apparatus for hoisting, lowering, pulling,
or retaining at any desired point weight or bodies of two pressers or
beds, one or both of which are elastic, and between which the fall of the
rope passes, substantially as herein-before described.

page_text: Sixth. The employment in driving machinery of a pulley or like
device with an elastic bed in combination with a clasp pulley or clasp
guide, or with a presser, roller, or pulley, or with a speeded pulley,
substantially as herein-before described.
In witness whereof, I, the said Martyn John Roberts, have here-
unto set my hand and scal, this Twenty-eighth day of April,
One thousand eight hundred and seventy-five.
MARTYN J. ROBERTS. (L.S.)