IMPROVEMENTS IN APPARATUS FOR RAISING AND LOWERING BODIES
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by Charles Denton Abel at the Office
of the Commissioners of Patents, with his Petition, on the 7th
November 1863.-A communication from abroad by Friederich Klingen-
feld, of Nürnberg, in the Kingdom of Bavaria, Professor.
I, CHARLES DENTON ABEL, of No. 20, Southampton Buildings, Chancery
Lane, in the County of Middlesex, Patent Agent, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR RAISING AND
LOWERING BODIES," to be as follows:-
This Invention relates to that description of apparatus for raising and
lowering bodies in which two pullies of different diameters are fixed upon one
and the same spindle, and having a chain or rope passed round them, and
round a separate suspended pulley to which the load is attached, effect the
raising or lowering of such load simply by being caused to revolve in one
direction or the other, owing to the difference in the circumference of the two
pullies and the consequent difference in the length of chain or rope that passes
over each pulley during one revolution.
The object of the present Invention is, firstly, to render the principle of
action of this apparatus applicable to the raising of greater weights than could
heretofore be accomplished; secondly, to afford a variable purchase for heavy
and light weights; thirdly, to provide a slow motion for raising loads, and a
quick motion for lowering the same or for letting down the chain when it has
been released of its load; and, fourthly, to prevent any slack chain from being
deposited on the ground when a load is being raised. For effecting these

page_text: objects two pulleys or drums of different diameters are connected together by
a clutch, or by other means, in such a manner that they can either revolve
independently of each other and in reverse directions when disconnected, or
they can be made to revolve together in one and the same direction when
connected. The spindles of these pullies or drums work in bearings at the
lower extremity of a framing which may be arranged in a similar manner to
that of the jib of a crane, and each spindle is provided with a crank handle.
At the upper extremity of the framing or jib are fixed three pullies placed in
a row, but revolving independently of each other, and a moveable block con-
taining two independent pullies and situated between the pullies or drums at
the bottom of the jib, which I will call the "differential pullies," and the
pullies at the top of the jib is connected to both by means of chains or ropes
in the following manner:-An endless chain passes first round one of the
differential pullies, then over one of the pulleys in the moveable block, then
round the other differential pulley, then over one of the pullies at the top of
the jib, then round the second pulley in the moveable block, and lastly round
another pulley at the top of the jib, whence it passes down to the first-named
differential pulley. To the moveable block is attached another chain that
passes over the third pulley at the top of the jib, and thence down to the
ground where the load to be raised is attached to it.
If it be required to
afford a greater degree of purchase for raising heavier loads than would be
attainable by placing the crank handles upon the spindles of the differential
pullies, a spur wheel may be formed on or fixed to the larger differential
pulley, and a small pinion be put in gear with the same, upon the spindle of
which pinion the handles are then placed. From the above description it will
be seen that if the two differential pullies be connected together and made to
revolve in that direction in which the chain is drawn by the larger pulley from
the smaller pulley, the moveable block will be made to travel from the upper
end of the jib to the lower end, and will thereby effect the raising of the load.
The speed with which this is effected may be varied according to the weight
of the load to be raised by placing the handles either upon the spindles of the
differential pullies or upon the spindle of the before-mentioned pinion. If the
differential pullies still remaining connected be made to revolve in the contrary
direction, the load will be lowered with the same velocity as that with which
it was raised; if, on the other hand, the differential pullies be disconnected
and made to revolve in contrary directions, they will effect the motion of the
moveable block in the one direction or the other, and consequently the raising
or lowering of the chain to which the loads are attached in a rapid manner.
If the chain from the moveable block passes directly over the pulley at the

page_text: top of the jib and down to the load, the distance through which the load can
be raised or lowered by this apparatus will evidently be equal to the distance
that the moveable block passes through in travelling from the pullies at the
top of the jib down to the differential pullies, or vice versa, but by providing
another pulley at the moveable block, or both at the moveable block and at
the top of the jib, and by causing the said chain to pass backwards and
forwards over these pullies before passing down to the load, the distance
through which the latter may be raised may evidently be made any required
multiple of the distance through which the moveable block passes. The
circumference of the differential pullies may be provided with cogs to work
into the links of the chain, or they may be formed in any other suitable
known manner for preventing the slipping of the chain.
Although I have described the apparatus as arranged to work in a similar
manner to an ordinary crane, yet it may also be applied in any other con-
venient manner, such as to a traveller.