IM- PROVEMENTS IN MACHINERY FOR RAISING AND LOWERING LANDING STAGES AND OTHER SIMILAR PLATFORMS OR STRUCTURES.
Year: 1875

page_text: LETTERS PATENT to Frederic Eliot Duckham, of Millwall Docks, in
the County of Middlesex, Engineer, for the Invention of "IM-
PROVEMENTS IN MACHINERY FOR RAISING AND LOWERING LANDING STAGES
AND OTHER SIMILAR PLATFORMS OR STRUCTURES.
PROVISIONAL SPECIFICATION left by the said Frederic Eliot
Duckham at the Office of the Commissioners of Patents, with his
Petition, on the 10th July 1875.
I, FREDERIC ELIOT DUOKHAM, of Millwall Docks, in the County of
Middlesex, Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN MACHINERY FOR RAISING AND LOWERING LANDING
STAGES AND OTHER SIMILAR PLATFORMS OR STRUCTURES," to be as follows:
-
My Invention relates to improvements in machinery for raising and
lowering landing stages and other lifting platform or bridges laden with
merchandize, vehicles, or otherwise, from one level to another by

page_text: hydraulic power. And my improvements have for their chief object to
maintain the stage or platform at all times in the horizontal position,
whatever may be its dimensions, and the unequal distribution of the
load upon it. To this end the hydraulic presses which lift one side of
the platform are coupled in such a way that their rams cannot move
otherwise than simultaneously and equally, the presses which lift the
opposite side being similarly coupled together so as to ensure simul-
taneous and equal rise or fall of both ends of the platform, and the
lifting chains on opposite sides are geared with the same cross shaft, so
that one side cannot rise or fall more rapidly than the other.
A convenient arrangement is to dispose a set of say two hydraulic
presses on suitable supports on each side of the stage or platform, the
presses on the same side being in line and coupled by connecting rods
attached to the cross heads of their rams, or by piston rods passing from
one ram or piston through glands in the end of its cylinder to the ram
or piston of the next cylinder or otherwise, so that the said rams or
pistons must move simultaneously and to an equal extent. The plat-
form is suspended by chains near either end, each chain passing over
suitable sheaves on its ram and cylinder, and round a pulloy at the side
of the platform, the chains on opposite sides being paired by passing
round and gearing with chain pulleys keyed on the same cross shafts
mounted beneath the platform. These shafts are caused to rotate in
raising and lowering the platform, and as the pulleys are keyed thereon
and gear with or grip the hoisting chains, the one chain cannot move
faster than the other. In this way the perfect horizontality of the
platform is maintained.
Office on the 10th January 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERIC 30
ELIOT DUCKHAM, of Millwall Docks, in the County of Middlesex,
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERIO 30
ELIOT DUCKHAM, of Millwall Docks, in the County of Middlesex,

page_text: 1
of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Frederic Eliot Duckham, Her
special licence, that I, the said Frederic Eliot Duckham, my executors,
administrators, and assigns, or such others as I, the said Frederic Eliot
Duckham, 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 MACHINERY FOR RAISING AND LOWERING
LANDING STAGES AND OTHER SIMILAR PLATFORMS OR STRUCTURES," upon the
condition (amongst others) that I, the said Frederic Eliot Duckham,
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 Frederic Eliot Duckham, 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, reference being had to the accom-
panying Sheet of Drawings and to the letters and figures marked
thereon, that is to say :-
My Invention relates to improvements in machinery for raising and
lowering landing stages and other lifting platforms or bridges laden with
merchandize, vehicles, or otherwise, from one level to another by
hydraulic power. And my improvements have for their chief object to
maintain the stage or platform at all times in the horizontal position,
whatever may be its dimensions and the unequal distribution of the load
thereon. To this end the hydraulic presses which lift one side of the
platform are coupled in such a way, that their rams cannot move other.
wise than simultaneously and equally, the presses which lift the opposito
side being similarly coupled together so as to ensure a simultaneous and
equal rise or fall of both ends of the platform, and the lifting chains on

page_text: opposite sides are geared with the same cross shafts, so that one side
cannot rise or fall more rapidly than the other.
A convenient arrangement is to dispose a set of say two hydraulic
cylinders on suitable supports on cach side of the stage or platform, the
presses on the same side being in line and coupled by connecting rods
attached to the cross heads of their rams, or by a piston rod passing from
one ram or piston through a gland in the end of its cylinder to the ram
or piston of the next cylinder, or otherwise, so that the said rams or
pistons must move simultaneously and to an equal extent. The plat
form is suspended by chains near either end, cach chain passing over
suitable sheaves on its rain and cylinder, and round a pulley at the side
of the platform, the chains on opposite sides being paired by passing
round and gearing with chain pulleys keyed on the same cross shafts
mounted beneath the platform. These shafts are caused to rotate in
raising and lowering the platform, and as the pulleys are keyed on the
shaft and gear with or grip the hoisting chains the one chain cannot
move faster than the other. In this way the platform is maintained
perfectly horizontal.
Figure 1 represents a side elevation of a landing stage for a steam
ferry worked by machinery arranged according to my Invention, and
Figuro 2 is a part plan and part horizontal section of the same.
A, A, is the stage or platform to be raised or lowered, and B, B, are
hydraulic cylinders fixed on girders X carried on a row of columns at
either side of the platform, or the cylinders B may be otherwise placed
and supported as may be most convenient. There are two or more
hydraulic cylinders B for working each side of the stage or platform A,
those on one side only being shown in Figure 2. They are placed in
line and their rams O work in the same direction, and are coupled
together by side rods D attached to the ram heads. These side rods
may work through guides E.
The rams may be otherwise coupled as shown in Figure 3 for instance,
which represents a part sectional elevation and plan of a pair of
hydraulic cylinders. In this case the cylinders have pistons F (instead
of rams or plungers) with piston rods G and a second piston rod H

page_text: passing through a packing at the other end of one of the cylinders (in
the case of two), and connected to the cross head of the piston of the
next cylinder. It will be obvious that the rams O in Figures 1 and 2
may be similarly connected by piston rods H; I are the chains by which
the platform is suspended. Each hydraulic cylinder is provided with a
single chain connected by one end at K to the cylinder, and passing
round multiplying sheaves L, M, L, M, L, in the order named, or
otherwise. The sheaves L, L', L³, are mounted on axes carried in
brackets on the head of the ram or piston rod, and the sheaves M, M',
are similarly mounted on the opposite end of the cylinder. From sheave
L, the chain passes over a guide pulley N mounted on the girders X,
thence round a chain wheel O beneath the platform up again to the
girders X, to which the other end of the chain is attached.
The chains may be otherwise arranged according as circumstances
may require, such arrangements forming no part of my Invention, which
in respect to the chains consists in gearing or pairing the chains at
opposite sides of the platform together, by keying the chain wheels O of
the two chains to be paired upon the same transverse shaft P mounted in
bearings beneath and supporting the platform.
In the case of four hydraulic cylinders there are two shafts Pas shown,
but the cylinders and shafts may be increased in number if necessary;
R are guide wheels to keep the chains in gear with the chain wheels O.
Instead of chain wheels O being keyed on a transverse shaft they may
turn loose, and the pulleys N be keyed on a transverse shaft instead,
such shaft being disposed at a suitable height above the highest position
of the platform, and the pulleys N being scored in same way as chain
wheels O to grip the chains and prevent slipping; Figure 4 shows such
an arrangement, only two hydraulic cylinders being used one at each
side.
Having described the nature of my Invention and the manner of
performing the same, I would observe that I lay no claim to the
employment of hydraulic power for the purpose of raising and lowering
landing stages or other platforms, but what I claim as the Invention to
be protected by the herein-before part recited Letters Patent is,-
First. Coupling the rams or pistons of the hydraulic cylinders which
are on the same side of the platform.

page_text: And, Secondly. Gearing together in pairs the supporting chains which
are at opposite sides of the platform, substantially as and for the purpose
herein shown and described.
In witness whereof, I, the said Frederic Eliot Duckham, havo here-
unto set my hand and seal, this Eighth day of January, in
the year of our Lord One thousand eight hundred and seventy-
six.
FRED. E. DUCKHAM. (L.s.)