Improvements in Duplex Hydraulic Hoists.
Year: 1886

page_text: Date of Application, 23rd Dec., 1886
Complete Left, 23rd Sept., 1887
Complete Accepted, 22nd Nov., 1887
Improvements in Duplex Hydraulic Hoists.
I FREDERIC MACDONELL EVANSON of 61 Lord Street Liverpool in the County of
Lancaster Engineer do hereby declare the nature of this invention to be as follows:-
The invention relates to hoists actuated by water or liquid under pressure, in which
a piston or plunger having a short stroke moves weights through a long distance by
means of two ropes or flexible carriers passing around pulleys, one rope descending
as the other ascends. Two or more cylinders may be used if desired.
The object is to construct such hoists so that weights may be lowered any required
distance continuously or intermittently and at any desired speed without loss of water
or liquid or expenditure of power. The invention consists First As regards single
cylinder hoists, in which a piston rod passes through both ends of the cylinder and
gives motion at each end to a rope or equivalent agent, in providing a passage
from one end of the cylinder to the other, and fitting such passage with a controlling
valve.
Second In making a single cylinder duplex hoist with an adjustable pulley or
pulleys around which the rope or flexible agent passes so as to allow the position
of the ropes or their equivalents to be varied.
Third When two cylinders are employed each having a piston or plunger actuating
a rope or its equivalent, communication controlled by a valve or valves is made from
cylinder to cylinder.
Fourth In double cylinder duplex hoists the position of the ropes or their equiva-
lents is adjusted by valve gear, by altering the position of a pulley or pulleys or both.
Water or other liquid at pressure is used as motive power and is admitted to
and exhausted from the cylinder or cylinders, in any usual way, and the arrange-
ment of the sheaves and pulleys, is of any desired and suitable character, but they
are so arranged, that one hauling rope or its equivalent, is raised whilst the other
is lowered.
The ends of the ropes or their equivalents are provided with hooks, cages, or
other means, for raising, and lowering, weights.
Dated this 22nd day of December 1886.

page_text: COMPLETE SPECIFICATION.
Improvements in Duplex Hydraulic Hoists.
I FREDERIC MACDONNELL EVANSON of 61 Lord Street Liverpool, in the County
of Lancaster Engineer do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
The invention relates to hoists actuated by water or liquid under pressure, in
which a piston or plunger having a short stroke moves weights through a long
distance by means of two ropes or flexible carriers passing around pulleys, one rope
descending as the other ascends. Two or more cylinders may be used if desired.
The object is to construct such hoists so that weights may be lowered any required
distance continuously or intermittently and at any desired speed without loss of
water or liquid or expenditure of power.
The invention consists First-As regards single cylinder hoists, in which a piston
rod passes through both ends of the cylinder and gives motion at each end to a rope
or equivalent agent ; In providing a passage from one end of the cylinder to the
other and fitting such passage with a controlling valve.
Second In making a single cylinder duplex hoist with an adjustable pulley or
pulleys around which the rope or flexible agent passes so as to allow the position of
the ropes or their equivalents to be varied.
Third When two cylinders are employed each having a piston or plunger actuating
a rope or its equivalent communication controlled by a valve or valves is made from
cylinder to cylinder.
Fourth In double cylinder duplex hoists the position of the ropes or their
equivalents is adjusted by valve gear by altering the position of a pulley or pulleys
or both.
Water or other liquid at pressure is used as motive power and is admitted to and
exhausted from the cylinder or cylinders in any usual way and the arrangement of
the sheaves and pulleys is of any desired and suitable character but they are so arranged
that one hauling rope or its equivalent is raised whilst the other is lowered.
The ends of the ropes or their equivalents are provided with hooks, cages or other
means for raising and lowering weights.
DESCRIPTION OF THE DRAWINGS.
b
Figure 1 is a view part in elevation and part in section of a single cylinder
hydraulic hoist under the First part of my invention, a cylinder, piston, e piston rod,
d pulleys ou piston rods e pulleys attached to brackets secured to the cylinders a,
guide pulley g raising and lowering ropes or equivalents, water supply and exhaust
pipes and valve. The above parts are constructed and arranged in any usual or
desired way, i pipe connecting one end of the cylinder a with the other, ; controlling

page_text: valve. When weights are being lowered, the motion of the piston b is regulated by
means of the valvej and water flows alternately from one end of the cylinder to the
other.
Under the Second part, a pulley such as for pulleys e are made adjustable so that
the two ends of the hoist may be made to work in unison at any required difference of
elevation.
Figure 2 is an elevation of a hoist under the third part of my invention, two
cylinders a,
a², are placed end to end and two plungers kk connected by a bar 7 are
fitted with pulleys and connections d e f g for raising and lowering, h supply and
exhaust pipes and valve, i pipe connecting the end of the cylinder a to the end of the
cylinder a, controlling valve. When weights are being lowered the water flows
from the end of one cylinder to the end of the other.
Figure 3 is an elevation of a modification of a two cylinder hoist in which the
plungers are connected end to end, the same letters of reference are used as in
Figure 2.
Figure 4 is an elevation of a modification of apparatus in which there are. two
cylinders, side by side, and in which two pistons are used, the same letters of reference
are used as in the preceding Figures, m pipe connecting the upper ends of the
cylinders, which are filled with liquid, which acts as a connection between the two
pistons. In a simpler form two plungers or rams are used instead of pistons and the
connection m is not employed.
In the above described two cylinder hoist a movable pulley or pulleys are used to
regulate the position of the hoisting ropes or their equivalents.
When the pistons or plungers of a two cylinder hoist are not connected, but are
free to act independently of each other, the relative positions of the said pistons or
plungers operating the raising or lowering ropes may be varied by means of valve
gear.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed-I declare that what I
claim is:
First The combination of duplex single cylinder hoists with a passage and valve
substantially in the manner and for the purpose set forth.
Second The combination of duplex single cylinder hoists with an adjustable pulley
or pulleys for the purpose set forth.
Third The combination of duplex hoists having two cylinders with a passage and
valve substantially in the manner and for the purpose set forth.
Fourth The combination of duplex hoists having two cylinders with an adjust-
able pulley or pulleys, or or valve gear, or both, for the purpose set forth.
Dated this 22nd day of September 1887.