IMPROVEMENTS IN TACKLE OR APPARATUS FOR RAISING AND LOWERING WEIGHTS.
Year: 1874

page_text: LETTERS PATENT to John Clayton Mewburn, of 169, Fleet Street, in
the City of London, Patent Agent and Consulting Engineer, for the
Invention of "IMPROVEMENTS IN TACKLE OR APPARATUS FOR RAISING AND
LOWERING WEIGHTS.". - A communication from abroad by Leon.
Verlinde, of Lille, France.
-
PROVISIONAL SPECIFICATION left by the said John Clayton Mew-
burn at the Office of the Commissioners of Patents, with his
Petition, on the 9th March 1874.
I, JOHN CLAYTON MEWBURN, of 169, Fleet Street, in the City of
London, Patent Agent and Consulting Engineer, do hereby declare the '
nature of the said Invention for ." IMPROVEMENTS IN TACKLE' OR APPARATUS
FOR RAISING AND LOWERING WEIGHTS," to be as follows:-
This Invention relates to tackle or apparatus for raising and lowering
weights, and has reference more particularly to the employment of
an endless screw or worm, as herein-after described.

page_text: The tackle or apparatus consists of two side plates or checks connected
together by stays which also form the bearings or supports for the shaft
of an endless screw or worm. There is another shaft below upon which
are fixed a worm wheel and a chain wheel, over which latter the lifting
chain is passed. At the upper part of the cheeks is another cross piece
to which is attached the swivelling hook by means of which the
tackle is suspended. On one of the ends of the shaft of the endless
screw is fixed another chain wheel over which an endless chain is passed;
on the other end of the same shaft there may be, if desired, a second
wheel or a counterweight.
•
The action is as follows:-The chain wheel on the shaft of the endless
screw receives the first motion by means of its chain, and this motion is
transmitted by the endless screw and worm wheel to the other chain
wheel over which the lifting chain is passed. The weight attached to
this chain is consequently raised or lowered as the case may be.
In some cases instead of attaching the weight directly. to the lifting
chain I carry the chain round a moveable sheave or block and secure one
end to a fixed point. The weight is then suspended from a hook on. the
moveable block.
In some cases also I employ two lifting chain wheels on the same
shaft, each being provided with its worm wheel, and the endless screw
being actuated between the worm wheels so as to gear into and drive
them both. The two lifting chains are attached to a single bar which
carries a hook to which the weight is attached.
In other cases I employ two lifting chain wheels on separate shafts at
different levels, but still driven by the same endless screw which gears
into the worm wheels on both shafts.
.
In other cases I add to the last described arrangement a toothed
pinion on the shaft of each worm wheel, the two toothed pinions
gearing respectively with two toothed wheels keyed to the two lifting
chain wheels.
The endless screw before desscribed may have one or more threads.

page_text: :
'
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Clayton Mewburn in the Great Seal
Patent Office on the 7th September. 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CLAYTON MEWBURN, of 169, Fleet Street, in the City of London, Patent
Agent and Consulting Engineer, send greeting.
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of March, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors
give. and grant unto me, the said John Clayton Mewburn,. Her
special licence that I, the said John Clayton Mewburn, my exccutors,
administrators, and assigns, or such others as I, the said John
Clayton Mewburn, 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 TACKLE OR APPARATUS FOR RAISING AND
LOWERING WEIGHTS" (a communication from abroad by Leon Verlinde, of
Lille, France), upon the condition (amongst others) that I, the said
John Clayton Mewburn, my executors or administrators, by an instru-
ment in writing under 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 John Clayton Mewburn, 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, reference being had to the
accompanying Drawings, that is to say :-
This Invention relates to tackle or apparatus for raising and lowering

page_text: upon
The improved tackle or apparatus is represented in the annexed
Drawings, and consists of two side plates or cheeks A, A, connected.
together by stays B, B, which also form the. bearings or supports for the
shaft D of an endless screw or worm E.. There is another shaft F below,
which are fixed a worm wheel G with which the worm E gears, t
and three chain wheels P (the number of which is variable) over which
latter the lifting chain I is passed: The chain I also passes over other
wheels P¹ carried in a movable frame H; the course of the chain is
clearly shewn in the Drawing, one end being secured at K. The frame
H has a hook L to which. the weight to be raised or lowered is attached..
At the upper part of the cheeks A is another cross, piece M to which, is.
attached the swivelling hook. N, by means of which the tackle is sus-.
pended. On one of the ends of the shaft D of the endless screw is fixed.
another chain wheel O over which an endless chain Q is passed.. The
other, end of the shaft D works in a horizontal socket C formed in one of. 1
the stays B..
The action is as follows:- The chain wheel' O on the shaft of the
endless screw receives the first motion by means of its chain Q, and this
motion is transmitted by the endless screw E and worm wheel G to the
chain wheels P on which the chain I is passed. The frame Ha
together with the hook L, and the weight suspended therefrom are con-
sequently raised or lowered as the case may be.
:
The endless screw E may have one or more threads.
And having now described the nature of the said Invention and in
what manner the same is to be performed, I declare that I claim, con- 2
structing tackle or apparatus for raising and lowering weights sub-.
stantially as herein-before. described and represented in the annexed
Drawings..
In witness whereof, I, the said John Clayton Mewburn, have here..
unto set my hand and seal, this Second day of September,
One thousand eight hundred and seventy-four.