An Automatic Safety-valve for Hydraulic Cranes, Hoists, and Passenger Lifts.
Year: 1889

page_text: Date of Application, 2nd Feb., 1889
Complete Specification Left, 1st Nov., 1889-Accepted, 7th -ec.,
1889
PROVISIONAL
SPECIFICATION.
An Automatic Safety-valve for Hydraulic Cranes, Hoists, and
Passenger Lifts.
I, TIMOTHY HARRIS of 20 South Market Street, Newport in the county of
Monmouth, engineer, do hereby declare the nature of this invention to be as
follows:-
This invention consists in the use of a check valve in connection with hydraulic
cranes, hoists and lifts.
The valve, which is in the form of a disc, is contained in a chamber fixed to and
communicating with the pipe through which the water flows to and from the ram
cylinder.
It is situated between the ram cylinder and the valves whereby the water is admitted
to and exhausted from the pipe communicating with the ram cylinder.
Extending upwards from the valve disc is a spindle which passes through a stuffing
box into a cylinder surmounting the valve chamber.
In the cylinder is a piston carried on the valve spindle. Below the piston is an
orifice which communicates with the hydraulic main. Above the piston and between
it and the cover of the cylinder is a spiral spring coiled around the valve spindle.
When the stop valve which governs the water supply from the accumulator is opened,
the piston aforesaid is immediately raised and the disc valve lifted to afford a clear
way for the flow of water to and from the working valves through which the water is
admitted to and exhausted from the ram. In event of failure, through fracture of the
main pressure pipe, or other cause, in water pressure acting against the ram, the
piston descends and the check valve is immediately forced down into its seat by
the spiral spring acting above on the piston in the cylinder aforesaid, and the returning
water, prevented from escaping, assists in keeping the valve closed. The ram is thus
held stationary. Other kinds of springs than the spiral spring described may be
employed to close the valve.
Datal thin 1
1000
NICHOLAS WATTS,
Applicant's Agent.
COMPLETE SPECIFICATION.
An Automatic: Safety-valve for Hydraulic Oranes, Hoists, and
Passenger Lifts.
I, TIMOTHY HARBIS, of 20 South Market Street, Newport, in the County of
Monmouth, engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to he particularly described and ascertained
in and by the following statement :-
This invention consists in a check valve for use in connection with hydraulic
cranes, hoists, lifts and the like and is designed to prevent, by maintaining the
ram stationary, injury to persons and property in event of failure in the pressure
of the water by which the ram is actuated.
The valve, which is in the form of a disc, is contained in a chamber communi-
cating with the pipe through which the water flows to and from the ram cylinder
and is situated between the latter and the valves whereby the water is admitted
to and exhausted from the pipe communicating with the ram cylinder.
Extending upwards from the valve disc is a spindle which passes through a
stuffing box into a cylinder surmounting the valve chamber and in which is a
piston carried on the valve spindle. Below this piston is an orifice by which the

page_text: cylinder communicates with the hydraulic main. Above the piston and between
it and the cover of the cylinder is a spiral spring coiled about the valve spindle.
When the stop valve which governs the water supply from the accumulator is
opened, the piston aforesaid is immediately raised and the disc valve lifted to afford
a clear way for the flow of water to and from the working valves through which
the water passes to and from the ram.
In event of failure in the pressure of water, through fracture of the main
pressure pipe, or other cause, the piston in the cylinder surmounting the disc valve
is immediately forced into its seat by the spiral spring acting on the upper face
of the piston, and the returning water from the ram, prevented by the disc
valve from escaping, assists in keeping the latter closed. The ram is thus held
stationary.
The figure shown in the appended drawing represents a vertical section of an
automatic safety valve constructed and arranged, in accordance with this invention,
for use in connection with hydraulic cranes, hoists, lifts and the like.
The valve consists of a disc a having a soat a³.
The valve chamber a³ com-
municates by the throat b with the working valves by which the water is admitted
to and exhausted from the ram. By the throat c the chamber a³ communicates
with the ram.
:
Extending upwards from the valve disc a is a spindle d which passes through
a stuffing box into the cylindrical chamber e in which is a piston f carried on the
said spindle d. At the bottom of the cylinder is an orifice g leading to a pipe
communicating with the hydraulic main.
Above the piston é and between it and the underside of the cover of the cylinder e
is a spiral spring i coiled. around the spindle d. k is an air-hole. When the
stop valve which governs the water supply from the accumulator is opened, the
water enters the cylinder e by the orifice g, the piston f is forced upwards com-
pressing the spring. i, and the valve a is raised to permit the flow of water from
the working valves to the ram. In event of failure in the pressure of water,
through fracture of the main pressure pipe or other cause, the piston f descends
and the check valve a is immediately forced down on to its seat by the action of
the spring i.
Thus the water returning from the ram is prevented from escaping and, acting
above the valve, keeps it firmly closed, holding the ram stationary.
Instead of the coiled spring, other forms of spring may be employed for the
same purpose.
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 a hydraulic crane, hoist, lift and the like, the use, between the working
valves and the ram, of a valve such as a the spindle of which is fitted with a
piston such as surmounted by a spring such as i, or its equivalent, and working
in a chamber such as e communicating at the bottom, by an orifice or channel 9,
with the water supply by which the ram is actuated, all constructed, arranged
and operating, substantially as hereinbefore described with reference to the accom-
panying drawing and for the purpose specified.
Dated this 28th day
L1000
NICHOLAS WATTS,
Applicant's Agent.