IMPROVEMENTS IN SHEAVES OR PULLEYS, FOR PAYING OUT AND HAULING IN ROPES, CHAINS, AND CABLES, FOR COMMUNICATING MOTION TO MACHINERY, AND FOR OTHER USEFUL PURPOSES
Year: 1859

page_text: LETTERS PATENT to Thomas Clarke, of Hackney, in the County of
Middlesex, Engineer, for the Invention of "IMPROVEMENTS IN SHEAVES OR
PULLEYS, FOR PAYING OUT AND HAULING IN ROPES, CHAINS, AND CABLES, FOR
COMMUNICATING MOTION TO MACHINERY, AND FOR OTHER USEFUL PURPOSES."
Sealed the 27th October 1859, and dated the 28th April 1859.
PROVISIONAL SPECIFICATION left by the said Thomas Clarke at the
Office of the Commissioners of Patents, with his Petition, on the 28th
April 1859.
I, THOMAS CLARKE, of Hackney, in the County of Middlesex, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
SHEAVES OR PULLEYS FOR PAYING OUT AND HAULING IN ROPES, CHAINS, AND CABLES,
FOR COMMUNICATING MOTION TO MACHINERY, AND FOR OTHER USEFUL PURPOSES," to
be as follows:
My Invention consists in constructing sheaves or pulleys in two parts. in
such manner that one or both of the flanges or sides of the groove in which
the rope or cable travels shall be capable of being moved, so that the two
may be brought together or towards each other at one part of the circum-
ference of the pulley, and nip or grip the rope at that part, while the rope
may travel freely over the other part of the pulley. The motion of the
movable part or parts, and therefore the gripping action, are, produced by
means of weighted levers, springs, inclined axles, or otherwise. The gripping

page_text: faces of the flanges or sides of the groove may be furnished with roughened
steel plates, or with vulcanized rubber, or other like suitable material,
according to the nature of the rope, chain, or cable being payed out or
hauled in, or otherwise operated upon.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Clarke in the Great Seal Patent Office on the
28th October 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
CLARKE, of Hackney, in the County of Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of April, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Clarke, Her special licence that I, the said Thomas Clarke, my
executors, administrators, and assigns, or such others as I, the said Thomas
Clarke, my executors, administrators, and assigns, should at any time 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 SHEAVES OR
PULLEYS FOR PAYING OUT AND HAULING IN ROPES, CHAINS, AND CABLES, FOR
COMMUNICATING MOTION TO MACHINERY, AND FOR OTHER USEFUL PURPOSES,"
upon the condition (amongst others) that I, the said Thomas Clarke, 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 per-
formed, 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 Thomas Clarke, 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 Drawings hereunto
annexed, that is to say:-
My Invention consists in constructing sheaves or pulleys in two parts, in
such manner that one or both of the flanges or sides of the groove in which

page_text: the rope or cable travels, shall be capable of being moved, so that the two
may be brought together or towards each other at one part of the circum-
ference of the pulley, and nip or grip the rope at that part, while the rope
may travel freely over the other part of the pulley. The motion of the
movable part or parts, and therefore the gripping action, are produced by
means of weighted levers, springs, inclined axles, or otherwise. The gripping
faces of the flanges or sides of the groove may be furnished with roughened
steel plates, or with vulcanized rubber, or other like suitable material, according
to the nature of the rope, chain, or cable being payed out or hauled in, or
otherwise operated upon.
Figure 1 of the accompanying Drawings is an end elevation of a sheaf or
pulley constructed according to my Invention. A, B, are two flanges mounted
on separate axles C, D. These flanges when together form a sheaf or pulley,
as shown, and the grip on the rope is obtained at one part of the circumference
by inclining the axle or shaft according to the grip required to be produced;
the rope travels freely except over the part where the grip is obtained;
Figure 2 is an end elevation of a sheaf or pulley, in which the face or part on
which the rope travels is corrugated as shown in order to produce a greater
gripping action. This pulley is also mounted on separate axles similar to that
just described. Figure 3 is a vertical section of a pulley, in which one axle
or shaft carries both flanges. A is one flange keyed to the shaft B; C is the
other flange, which is formed with a conical boss C¹, which presses against a
boss D keyed to the shaft A. By this arrangement the rope runs free at the
lower part of the pulley, but is gripped at the upper part, as shown at E; in
this case as the strain on the rope increases, so in proportion does the gripping
action. Figure 4 is a vertical section of a pulley, being a modification of the
arrangement just described. A is a flange keyed to the axle or shaft B;
C is a second flange, loose on the shaft B, which forms with the flange A a
pulley or sheaf; D, D, are series of springs round the pulley, which press the
flange C at its upper part against the rope, whilst at its lower a fixed roller E
presses outwards against the springs D, D, and allows the rope to run freely.
Figure 5 is a vertical section on an enlarged scale of the gripping end of a
sheaf or pulley, constructed as before described, the jaws A, A', of which are
furnished with a serrated or roughened edge, in order to produce a greater
gripping action; Figure 6 is a similar view, showing the rope gripped;
Figure 7 is a section of a similar sheaf or pulley in which vulcanized india-
rubber or other elastic material is employed instead of the serrated edge just
described; and Figure 8 is a similar view, in which the rope is shown running
freely; Figure 9 is a side elevation, partly in section, of an apparatus for

page_text: regulating or controlling the paying out or hauling in of ropes or cables; and
Figure 10 is an end elevation of the same:
A is a pulley or sheaf constructed in the manner before described with
reference to Figure 1, and supported in bearings formed in the frame B. The
rope C passes first round a pulley D, then round the pulley A, and from thence to
another pulley E, which is supported by a bell-crank lever F, centred at G, the
long arm Hof which is attached to springs I, I; L is a weighted lever jointed
to another lever L' that presses against the shaft, which carries the pulley or
sheaf, which allows the flanges to yield to any inequalities that may be in the
rope. As tension is exerted on the rope it is gripped by the pulley A in the
manner before described, and the amount of tension exerted on the rope is
indicated by a pointer J on a scale plate K.
And having now described the nature of the said Invention and in what
manner the same is to be performed, I declare that I do not claim the con-
struction of such sheaves or pulleys when applied to the working of agricultural
machinery, as some similar sheaves have been proposed for such purpose; but
I claim for all purposes other than that last named, the construction of sheaves
or pulleys in two parts, in order that a gripping action may be exerted on the
rope travelling through or over them, substantially in the manner herein-
before described.
In witness whereof, I, the said Thomas Clarke, have hereunto set my
hand and seal, this Twenty-seventh day of October, One thousand
eight hundred and fifty-nine.
THOMAS CLARKE. (L.S.)