Improved Apparatus for Regulating Hydraulic Power.
Year: 1890

page_text: Date of Application, 10th June, 1890-Accepted, 12th July, 1890
COMPLETE SPECIFICATION.
Improved Apparatus for Regulating Hydraulic Power.
I, ROBERT HENRY THORPE of 27 Buckland Crescent, Belsize Park, in the County
of Middlesex, 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 relates to that class of apparatus designed for the purpose of
regulating the power and to a certain extent the quantity of liquid employed for
effecting varying quantities of work, or in other words for enabling the same apparatus
to work at a higher or lower power, depending upon the work it is called upon to
perform, the supply or pressure from the main being constant throughout. I
accomplish this result by varying the effective piston area as hereinafter described.
In order that my invention may be clearly understood reference is made to the
accompanying drawings which illustrate my invention as applied to a double
power
motor cylinder A, containing a piston B, and ram or piston rod C, all of ordinary
construction, the balanced valve being shown in Fig. 1 in position for full power to be
applied, in Fig. 2 for reduced power with decreased consumption of water, while
Fig. 3 represents the arrangement applied to a double cylinder motor under full
power.
Referring first to Figs. 1 and 2 it will be seen that one end of the cylinder A is
connected to the main or supply pipe D, the inflow being governed by the hand
valve E and slide valve F, the latter also governing the direct exhaust through pipe G
from this end of the cylinder. A branch pipe I connects the pressure end of the
cylinder A with cylinder J, the piston K of which forms one end of the rod which
carries the balanced piston valve H, the other end of said rod being attached to a
similar piston M, working in cylinder N, connected by pipe O to the main or other
source of supply D at a point beyond valves E, F, in order that the full main pressure
may always be exerted therein. Attached to rod L is a weighted lever P pivoted
at Q, the action of which will be hereafter described. The valve H is connected
through ports or pipes R and S with the respective ends of cylinder A and by pipe T
with the exhaust G.
When the parts are in the position shown in Fig. 1 the full pressure entering
through D is exerted behind the piston B, the other end of the cylinder A being open
to exhaust G through valve H by pipes S, T, initial pressure also being exerted on
piston K, and full main pressure on M. The piston B having completed the desired
stroke the valve F is moved, shutting off the supply through and opening the direct
exhaust from behind B to G. The pressure on K being relieved the direct pressure
on M overcomes the friction of valve H which is moved in direction of least
resistance over to the position shown in Fig. 2, this movement being assisted by
weight P so soon as it leaves its central or vertical position.
With the parts in the position shown in Fig. 2 the apparatus is adapted to work at
a lower power with a decreased consumption of water as the piston is open to pressure
on both sides the power exerted is proportionate to the difference in area of piston B
on opposite sides. So long as the work to be done by C can be effected at the lower
power so long will the pressure on M plus the leverage pressure of P be sufficient to
hold valve H in the position shown as against the pressure on K, which as is well
known will vary in proportion to the resistance of piston B or of the work to be done.
The areas of pistons K and M and the leverage exerted by P can be proportioned
so that full power shall only be put on piston B when the resistance or work to be
done calls for a pressure above a certain number of lbs. to the square inch.
For the purpose of illustration let it he assumed that with the parts in the position
shown in Fig. 2 it will take a pressure of 500 lbs. to the square inch on K to overcome
the pressure on M plus the resistance of weight P (which latter offers a gradually

page_text: reduced resistance as it more nearly approaches its perpendicular position at which
point it exerts no pressure in either direction) while if the pressure on K be only
250 lbs. per square inch or less, the pressure on M will be sufficient to start the valve,
and weight P will then assist and cause valve H to be carried rapidly home to the
position shown in Fig. 2. This arrangement will cause the valve to remain stationary
until a considerable difference of pressure takes place over that at which it was thrown
over, and when it does move it wilt rapidly attain the desired position. By the action
of the weight and the application of the initial pressure of the motor cylinder in
opposition to the constant pressure in the main, the motion and piston of the valve H
is automatically adjusted to meet the work required to be done by giving the power
best suited to it, the lower power being always on unless the higher is required.
It will of course be evident that any uniform or given resistance such as a spring
may be substituted for cylinder N and piston M, and that a spring or other device
may be substituted for the weight P, but I prefer to use the parts as shown.
Fig. 3 indicates the invention when applied to a double cylinder motor, full pressure
being applied to both pistons. As the operation is substantially as previously
indicated further description is deemed to be unnecessary. In an analogous manner
the invention may be applied to triple cylinder motors or the like.
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. The combination with a motor cylinder and piston, channels connecting the
piston rod end of the cylinder with the working end and with the exhaust and a valve
for controlling communication through said channel, of two pistons for reciprocating
the valve, one piston receiving pressure from the motor cylinder and the other a
constant pressure as from the main, substantially as described.
2. In combination with a motor cylinder and piston, channels connecting the piston
rod end of the cylinder with the working end and with the exhaust, an automatically
operated valve for controlling communication through sail channels, and a supply and
exhaust port communicating with the working end of the cylinder, substantially as
described.
3. The combination with the cylinder, piston, and piston rod, of a channel outside
the piston connecting the opposite ends of the cylinder, a valve and means for
automatically operating it constructed to complete said channel when in one position,
and also when shifted to open communication between the exhaust and the piston rod
end of the cylinder, and an inlet port communicating with the opposite end of the
cylinder, substantially as described.
4. In combination, a motor cylinder and piston, channels connecting the piston rod
end of the cylinder with the working end and with the exhaust, a valve for controlling
said channels, pistons of different sizes for operating the valve, and a weighted lever
connected to the valve and opposing its movement by the larger piston, substantially
as described.
5. In combination with a motor cylinder and piston, passages communicating with
opposite ends of said cylinder and an exhaust passage, a valve controlling said
passages, a piston K within cylinder J for moving said valve in one direction and a
piston M within cylinder N for moving said valve in the opposite direction, said
cylinders communicating respectively with the motor cylinder and supply main,
substantially as described.
6. In combination, two or more cylinders communicating through a valve adapted
to normally close the pressure to the second of said cylinders but to automatically
open the communication when the pressure in the first cylinder is insufficient for the
work to be done, all substantially as set forth.
Dated this 10th day of June 1800
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Applicant's Agent.