Improvements in Valves for Hydraulic Lifts and the like.
Year: 1898

page_text: I, GEORGE ANDREWS, of 14, Laurie Grove, New Cross, London, S.E., Engineer,
do hereby declare the nature of my said invention to be as follows:
-
The object of my invention is to effect improvements in the construction of
valves for hydraulic lifts and the like.
According to my invention I fit the usual slide valve for governing the passage
of the water under pressure to the cylinder and exhausting the same, and in
addition thereto I fit two lift valves, one being the ordinary lift valve covering a
small relief passage leading from the induction port to the valve chest, and the
other valve being a similar lift valve covering the supply port through which the
high pressure water is supplied to the valve chest, acting as a controlling valve.
By the use of my invention the cylinder is effectually controlled when the supply
is shut off, the controlling valve preventing the passage of the water to the supply
pipe, also preventing the lifting of the slide valve, and preventing the rapid
descent of the plunger on the bursting of a pipe.
1
1000
GEORGE DOWNING & SONS,
8, Quality Court, London, W.C., Agents.
Improvements in Valves for Hydraulic Lifts and the like.
I, GEORGE ANDREWS, of 14, Laurie Grove, New Cross, London, S.E., Engineer,
do hereby declare the nature of my said invention and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement; -
The object of my invention is to effect improvements in the construction of
valves for hydraulic lifts and the like.
According to my invention I fit the usual slide valve for governing the passage
of the water under pressure to the cylinder and exhausting the same, and in
addition thereto I fit two lift valves, one being the ordinary lift valve covering a
small relief passage leading from the induction port to the valve chest, and the
other valve being a similar lift valve covering the supply port through which the
high pressure water is supplied to the valve chest, acting as a controlling valve.
By the use of my invention the cylinder is effectually controlled when the supply
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page_text: is shut off, the controlling valve preventing the passage of the water from the
cylinder and valve chest to the supply pipe; also preventing the lifting of the
slide valve, and preventing the dangerous and usually rapid descent of the plunger
on the bursting of a pipe.
And in order that my said invention may be particularly described and ascer-
tained, reference is hereby made to the accompanying drawings, in which similar
figures of reference indicate corresponding parts.
Fig. 1 is a sectional elevation illustrating the application of my invention to the
valve chest of an ordinary hydraulic lift.
Fig. 2 is a plan of the valve face and valves, the slide valve being removed.
3 is the slide valve.
4 is the induction passage leading to the cylinder. 5 is
the eduction passage. 6 is the ordinary lift relief valve, pivoted at 7, and covering
the relief passage 8.
9 is my improved valve formed (preferably) integral with
the valve 6 and pivoted at 7.
Any other suitable form of valve may however be used. 10 is the supply
passage from the accumulator or other source of hydraulic power.
In case, from any cause, the initial pressure of the water should become reduced
while the lift or analogous article is raised, the valve 9 immediately by the action
of the back pressure, closes the supply port 10, and thus sustains the pressure in
the cylinder and valve box, whereby the lift or the like is prevented from falling
until the slide valve is reversed.
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:-
In hydraulic lifts and the like, the application and use of a controlling valve
capable of closing the supply port by the back pressure of the water on the occur-
rence of a reduction of initial pressure in the supply, substantially as and for the
purposes hereinbefore described and illustrated by the drawings.
Dated 18th November 1898.
GEORGE DOWNING & SONS,
S, Quality Court, London, W.C., Agents.