IMPROVE- MENTS IN PULLEY BLOCKS OR APPARATUS FOR RAISING HEAVY WEIGHTS
Year: 1869

page_text: LETTERS PATENT to Robert Marsden, of the Tinsley Park Works,
Sheffield, in the County of York, for the Invention of "IMPROVE-
MENTS IN PULLEY BLOCKS OR APPARATUS FOR RAISING HEAVY WEIGHTS"
Sealed the 12th April 1870, and dated the 30th October 1869.
PROVISIONAL SPECIFICATION left by the said Robert Marsden at the
Office of the Commissioners. of Patents, with his Petition, on the
30th October 1869.
I, ROBERT MARSDEN, of the Tinsley Park Works, Sheffield, in the
County of York, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN PULLEY BLOCKS OR APPARATUS FOR RAISING HEAVY WEIGHTS,"
to be as follows:-
I make use of the well known principle of the endless screw or worm
and worm wheel, and by a novel arrangement of parts I make them
applicable to the purposes for which pulley blocks are ordinarily used,
that is, for the purpose of moving or raising heavy weights; thus I make
by casting in malleable or cast iron or other metal a worm wheel of the

page_text: size I require, and then by cutting or casting make a worm or endless
screw to correspond with and work into such wheel. I then make either
in cast or malleable iron or by forging a frame which shall contain the
hook from which the whole is to be suspended, and likewise the above
worm and wheel, the worm being carried in suitable bearings either in the
top or the bottom of the frame, and the axis of the worm wheel in bearings
in the side cheeks thereof. I then make a small cast-iron pulley to
carry the lifting chain, which is made to run freely on its axle, which is
also the axle of the worm wheel, and which gears into the above worm
wheel by means of clutches cast on to the sides of the said wheel and pulley
respectively; the clutches are forced together by means of a spring fixed
to one of the side checks of the frame. On the side of the frame
mentioned above I place a small bent lever which acting on the chain
pulley compresses the spring and draws the pulley out of gear, by which
the chain runs freely and can be at once adjusted to its work. I then
attach either a chain or spocket wheel or rope wheel over which a hand
chain or rope is worked to the end of the spindle upon which the worm
is placed, and the whole of the parts are then complete.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Marsden in the Great Seal Patent Office
on the 30th April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
MARSDEN, of the Tinsley Park Works, Sheffield, in the County of York,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of October, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Robert Marsden, Her special licence that
I, the said Robert Marsden, my executors, administrators, and assigns,
or such others as I, the said Robert Marsden, my executors, adminis-
trators, 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;

page_text: and Isle of Man, an Invention for "IMPROVEMENTS IN PULLEY BLOCKS OR
APPARATUS FOR RAISING HEAVY WEIGHTS," upon the condition (amongst
others) that I, the said Robert Marsden, 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 Robert Marsden, do hereby declare
the nature of the 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, that is to say :-
This Invention has for its object improvements in pulley blocks or
apparatus for raising heavy weights.
I make use of the well-known principle of the endless screw or worm
and worm wheol, and by a novel arrangement of parts I make them
applicable to the purposes for which pulley blocks are ordinarily used,
that is, for the purpose of moving or raising heavy weights; thus I
make by casting in malleable or cast iron or other metal a worm wheel
of the size I require, and then by cutting or casting make a worm or
endless screw to correspond with and work into such wheel. I then
make either in cast or malleable iron or by forging a frame which shall
contain the hook from which the whole is to be suspended, and likewise
the above worm and wheel, the worm being carried in suitable bearings
cither in the top or the bottom of the frame and the axis of the worm
wheel in bearings in the side cheeks thereof. I then make a small cast-
iron pulley to carry the lifting chain which is made to run freely on its
axle, which is also the axle of the worm wheel, and which gears into the
above worm wheel by means of clutches cast on the sides of the said
wheel and pulley respectively; the clutches are forced together by
means of a spring fixed to one of the side cheeks of the frame. On the
side of the frame mentioned above I place a small bent lever which
acting on the chain pulley compresses the spring and draws the pulley
out of gear by which the chain runs freely and can be at once adjusted
to its work. I then attach either a chain or spocket wheel or rope wheel
over which a hand chain or rope is worked to the end of the spindle upon
which the worm is placed, and the whole of the parts are then complete.

page_text: and readily carried into effect, I will proceed to describe the Drawings
hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side view of a pulley block constructed according to my
Invention.
and i have
revolves it
a, a, is the frame, and the hook by which it is suspended;
c, an axis carried by the frame and having upon it the worm d and
the hand chain wheel e; fis a hand chain passing over the wheel e, and
by it the axis c is rotated to raise and lower the weight; g is an axis
carried by the checks of the frame and having fixed upon it the worm
wheel which gears with the worm d; i is a chain wheel to receive the
lifting chain ; it is mounted loosely on the axis y and is pressed
towards the worm wheel by the spring 1. The wheels
clutching projections upon them, so that when the wheel
carries the wheel i with it. These projections are clearly shown in
Figures 2 and 3 which are side views of the wheels h and i respectively.
The projections are somewhat inclined so that the strain on the lifting
chain has a tendency to hold the parts of the clutch together; m is a
lever with a cord n attached to it; by pulling this cord the wheel i is
drawn out of gear with the wheel h, and then the wheel i is able to turn
freely to allow the lifting chain to be adjusted to its work without loss.
of time.
Having thus fully described, the nature of my Invention, and the
manner in which it is to be carried into effect, I wish it to be under-
stood that I claim as my Invention the application of the worm and
wheel or endless screw and wheel to the purpose aforesaid in the
manner as set forth and shown in the annexed Drawings.
In witness whereof, I, the said Robert Marsden, have here-
unto set my hand and seal, this Twenty-eighth day of April,
in the year of our Lord One thousand eight hundred and
seventy.
ROBERT MARSDEN. (L.s.)