Improvements in Telescope Hydraulic Lifts.
Year: 1887

page_text: Date of Application, 22nd July, 1887
Complete Left, 21st Apr., 1888
Complete Accepted, 25th May, 1888
Improvements in Telescope Hydraulic Lifts.
1, ALEXANDER CHARLES MOFFATT, of 26 College Street, Dowgate Hill, in the City
of London, Engineer, do hereby declare the nature of this invention to be as
follows:-
:-
This invention has for its object improvements in telescope hydraulic lifts.
In my improved lift a series of upright cylinders, one placed within the other is
employed. The lowest cylinder remains stationary but the other cylinders move up
and down with the cage but the distances they travel are less. The lowest cylinder is
closed by a cover at its upper end and the second cylinder passes out through the
cover by a gland, which is rendered tight by means of a cupped leather. At the
lower end of this second cylinder is a piston fitting accurately to the interior of the
lowest cylinder. Within the second cylinder in like manner is a third cylinder with
a piston at its lower end and passing out through a gland at the top, and so on for as
many cylinders as may be required. The last cylinder is fitted with a piston and solid
ram and the ram carries the cage of the lift. The spaces between the walls of these
cylinders are filled with liquid and when by pressure exerted upon the lowest piston
it, with its ram, is caused to rise, liquid is expelled from between the walls to the
lowest cylinder and the second cylinder and this liquid is forced into the space within
the second cylinder. The pressure which this liquid exerts on the piston in the second
cylinder causes this piston also to rise; and so in like manner the piston in each one
of the cylinders moves upwards in the cylinder in which it is contained. The ultimate
rise of the ram which carries the cage of the lift is as will be seen several times
greater than the distance through which the piston in the lowest cylinder rises.
Telescopic cylinders such as I have described have before been constructed and I
do not claim them as novel, but heretofore the pressure upon the piston in the lowest
cylinder has been exerted by means of fluid adinitted beneath it. Now the diameter
of the lowest cylinder is necessarily considerable and if water supplied under high
pressure be employed to work the lift as is frequently convenient there is liable to be
an excessive consumption of water and a corresponding waste of power. Now accord-
ing to my invention I do not admit the high pressure water to operate against the

page_text: lower piston but beneath this piston I place a separate hydraulic cylinder and ram.
The rain abuts upon the piston, and when it rises it carries the piston up with it.
This ram and cylinder being altogether independent from the other parts of the lift
apparatus can be made of the size required to yield the power requisite for working
the lift, and the power is not wasted as heretofore by admitting the high pressure
water into a cylinder of unnecessarily large dimensions.
The space in the lowest cylinder beneath the piston being no longer required for
working the lift can be utilised to partially counterpoise the weight of the moving
arts; the space being connected by a pipe with an elevated tank and so kept full of
liquid at a suitable pressure.

page_text: I, ALEXANDER CHARLES MOFFATT, of 26 College Street, Dowgate Hill, in the City
of London, 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 :—
This invention has for its object improvements in telescope hydraulic lifts.
In my improved lift a series of upright cylinders, one placed within the other is
employed. The lowest cylinder remains stationary but the other cylinders move up
and down with the cage but the distances they travel are less. The lowest cylinder is
closed by a cover at its upper end and the second cylinder passes out through the
cover by a gland, which is rendered tight by means of a cupped leather. At the
lower end of this second cylinder is a piston fitting accurately to the interior of
the lowest cylinder. Within the second cylinder in like manner is a third cylinder
with a piston at its lower end and passing out through a gland at the top, and so on
for as many cylinders as may be required. The last cylinder is fitted with a piston
and solid ram and the ram carries the cage of the lift. The spaces between the walls
of these cylinders are filled with liquid and when by pressure exerted upon the lowest
piston it, with its ram, is caused to rise, liquid is expelled from between the walls to
the lowest cylinder and the second cylinder and this liquid is forced into the space
within the second cylinder. The pressure which this liquid exerts on the piston in
the second cylinder causes this piston also to rise; and so in like manner the piston
in each one of the cylinders moves upwards in the cylinder in which it is contained.
The ultimate rise of the ram which carries the cage of the lift is as will be seen
several times greater than the distance through which the piston in the lowest
cylinder rises.
Telescopic cylinders such as I have described have before been constructed and I
do not claim them as novel, but heretofore the pressure upon the piston in the lowest
cylinder has been exerted by means of fluid admitted beneath it.
Now the diameter
of the lowest cylinder is necessarily considerable and if water supplied under high
pressure be employed to work the lift as is frequently convenient there is liable to be
an excessive consumption of water and a corresponding waste of power. Now
according to my invention I do not admit the high pressure water to operate against
the lower piston but beneath this piston I place a separate hydraulic cylinder and ram.
The ram abuts upon the piston, and when it rises it carries the piston up with it.
This ram and cylinder being altogether independent of the other parts of the lift
apparatus can be made of the size required to yield the power requisite for working
the lift, and the power is not wasted as heretofore by admitting the high pressure
water into a cylinder of unnecessarily large dimensions.
The space in the lowest cylinder beneath the piston being no longer required for
working the lift can be utilised to partially counterpoise the weight of the moving
parts; the space being connected by a pipe with an elevated tank and so kept full of
liquid at a suitable pressure.

page_text: In order that my said invention may be more fully understood and readily carried
into effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figures 1 and 2 shew vertical sections of lifts constructed according to my
invention In Figure 1 the lift is shown at its lowest elovation, and in Figure 2 it is
shown partly raised.
In these figures A is the outer cylinder, which is fixed-B, C, D, are the cylinders
inside it, the piston a working in the cylinder A is fixed to the bottom of the cylinder B,
and the piston & working in the cylinder B is fixed to the cylinder C, and so on. A
ram E works in the cylinder D. Passages 61 c¹ are formed through the bottom of the
walls of the cylinders so as to allow fluid to flow from one to the other. The top of
the cylinder A is closed by a cover A'.
In the apparatus as thus described there is no novelty, usually however the piston a
has been forced up by the pressure of fluid admitted beneath it to the cylinder A. In
place of this arrangement I according to this invention mount the piston a upon a
ram working in a cylinder F.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A telescope hydraulic lift of the class described in which the lowest piston
is mounted upon the ram of an independent hydraulic cylinder, substantially as
described.
2. In apparatus such as is referred to in the first claim admitting fluid beneath the
lowest piston so as to partially counterpoise the weight of the moving parts, substantially
as described.
3. My improvements in telescope hydraulic lifts substantially as described.
Dated this 30th day of Annil 1000