Improvements in and relating to Hydraulic Lifts.
Year: 1893

page_text: Date of Application, 23rd May, 1893
Complete Specification Left, 23rd Feb., 1894-Accepted, 31st Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Hydraulic Lifts.
I, JOHN ALEXANDER STEVEN, of 12 Royal Crescent, Glasgow, Lanarkshire,
Engineer, do hereby declare the nature of my invention to be as follows:-
This invention has reference to and comprises improvements in and relating to
the valves and their working chambers of hydraulic lifts, whereby these are made
safer and more efficient in action than heretofore.
The improvements consist first in making the working chamber in two parts with
a faced and bored joint flange between the supply branch and space in the chamber,
and the discharge branch and space leading to the working hydraulic cylinder and
piston of the machine, so that the upper part with the inlet branch of the valve
chest may be made to swivel on the internal tubular lining and turned to any
desired angle in reference to the fixed part and branches.
A new valve and chamber is fitted preferably within the upper part of the main
valve chamber for preventing "knocking" or concussion when the machine is
suddenly stopped. This new or auxiliary valve is preferably made in the form of
a mushroom valve working down on a seat opening through both flanges of the
upper and lower parts into the chamber leading to the hydraulic cylinder, and
having its parallel stem working up through a snug on a side door in the small
escape chamber above the valve leading into the supply pressure chamber; all so
that when a sudden stoppage takes place the extra pressure caused in the working
chamber raises the valve and permits the water to escape back into the supply
chamber; and immediately again close the auxiliary valve when this action takes
place and prevents any concussion or "knocking."
The upper part of the main piston valve working within the lining is at the
extremity of its upward stroke made to come up against the domed top piece bolted
and jointed on the top of the valve chest, this top piece forming the stop being less
in diameter than the lining of the valve chest, and forms the bored guide for the
hollow toothed rack on top of valve spindle. This rack is formed at its extreme
upper end with a segmental projection which in its downward action comes against
the upper end of the bored guide part of the top and forms a stop for the valve at
the extremity of its downward stroke, the rack spindle of the valve being worked
as usual by the pinion and its lateral spindle passed out through a stuffing box in
this upper rack part. A hole is formed through the lower part of the pinion
chamber above the joint, from which a tube is led to carry away any waste water
that may escape through the upper packing ring of the valve, and might otherwise
fill this upper chamber and injure the joints.
Dated the 20th May 1893.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Hydraulic Lifts.
I, JOHN ALEXANDER STEVEN, of 12 Royal Crescent, Glasgow, Lanarkshire,.
Engineer, do hereby declare the nature of my invention, and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement in writing, that is to say :-
This invention has reference to and comprises improvements in and relating to
the valves and their working chambers of hydraulic lifts or machines, whereby
these are made safer and more efficient in action than heretofore.
And in order that my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, I have hereunto
appended an explanatory sheet of drawings in which
Figure 1 represents a sectional elevation of the valves and working chamber of
an hydraulic lift or machine as constructed in accordance with my improvements;
and
Figure 2 is a transverse section as taken on the line 1-1 of Figure 1.
Referring to these drawings:-The improvements consist first in making the
working chamber in two parts A A' with a faced and bored joint flange A²,
between the supply branch a and space in the chamber all and the discharge
branch and space a leading to the working hydraulic cylinder and piston of the
machine, so that the upper part A' with the inlet branch a of the valve chest may
be made to swivel and be turned to any desired angle in reference to the fixed
part A and branches, or vice versa the part A may be made to swivel and the
part A remain stationary.
"
A relief valve and chamber is fitted preferably within the upper part of the main
valve chamber for preventing
66 knocking or concussion when the machine is
suddenly stopped. This relief or auxiliary valve is preferably made in the form of
a mushroom valve c working down on a seat C opening through both flanges at A'
of the upper and lower parts A, A', into the chamber a leading to the hydraulic
cylinder a² and having its parallel stem c¹ working up through a socket in a snug or
arm on a side door in the small escape chamber above the valve c leading
through the orifice into the supply pressure chamber a"; all so that when a
sudden stoppage takes place the extra pressure caused in the machine and working
chamber a raises the valve c and permits the water to escape back into the supply
chamber a"; and immediately again closes the relief valve c when this action takes
place and prevents any concussion or knocking.
Brass liners are fitted within the working chamber and are preferably formed in
two separate parts b, b, and each have collars on their external surface said
collars being locked and sealed in position by the chest flanges at A², A³.
The upper part 6' of the main piston valve working within the lining is at the
extremity of its upward stroke made to come up against the domed top piece d, d',
bolted and jointed on the top of the valve chest A¹ this. top piece forming the
stop being less in diameter than the lining of the valve chest, and forms the bored
guide for the hollow toothed rack on top of valve spindle. This rack d² is
formed at its extreme upper end with a segmental projection d" which in its
downward action comes against the end of the bored guide part of the top and
forms a stop for the valve at the extremity of its downward stroke, the rack spindle
of the valve being worked as usual by the pinion d³ and its lateral spindle passed
out through a stuffing box in this upper rack part.
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 :-
First. In hydraulic lifts or machines, the forming of the working chamber in two

page_text: main parts, so that the one part with the inlet branch of the valve chest may be
made to swivel and be turned to any desired angle in relation to the other part, or
vice versa, substantially as herein described in reference to and by way of application.
shown in the accompanying drawings.
Second. In hydraulic lifts or machines, the fitting of a relief valve and chamber
in connection with the main valve chamber for preventing knocking or concussion
when the machine is suddenly stopped, substantially as herein described in reference:
to and by way of application shown in the accompanying drawings.
Dated the 22nd February 1891
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.