Improvements in Hydraulic Machinery.
Year: 1893

page_text: Date of Application, 2nd Jan., 1893
Complete Specification Left, 2nd Sept., 1893-Accepted, 21st Oct., 1893
PROVISIONAL SPECIFICATION.
Improvements in Hydraulic Machinery.
I, CHARLES CHRISTIANSEN, of 35 Calthorpe Street, Gray's Inn Road, in the
County of London, Engineer, do hereby declare the nature of this invention to be
as follows:-
My invention relates to improvements in the working of machinery actuated by
an incompressible or practically incompressible fluid such as water. In order to
obtain work from such a fluid it must be under pressure and this pressure may be
obtained in any well known manner. In the case of hydraulic lifts, cranes and
other similar machinery the high pressure water is caused to actuate a piston or
ram which moves in a suitable cylinder. The load upon a lift or crane varies
within wide limits and the objection to the ordinary methods of constructing
hydraulic apparatus is that, although they work efficiently at full load, they are
very inefficient at light loads. The reason of this is that as water is practically
incompressible the same volume of water or other fluid must be let into the lifting
cylinder whether a light or heavy load is to be lifted and therefore there is a serious
increase in the cost of working at any load less than the maximum for which the
machinery is designed.
In order to overcome these defects I have invented an apparatus which acts
automatically in such a way as to regulate the supply of high pressure water used
according to the power required in the lift or other apparatus.
In my invention the lift cylinder is connected to a chamber capable of containing
at least as much water as would fill the lift cylinder or in other words at least as
large a volume as is represented by the lift piston itself and the lift cylinder is
connected to the chamber in any suitable manner as for instance by a pipe. A
piston enters into this chamber and is of such a size that by a very short travel it can
displace the whole of the water required to fill the lift cylinder. It is therefore
obvious that if the high pressure water from the source of supply be caused to act
upon the back of such a piston it will displace it and produce an equal pressure
upon the water in the lift cylinder the whole apparatus being supposed free from
air. In this case there would be no saving, but according to my invention I
construct the special piston of a stepped cylindrical form something like a speed
cone, and I so arrange glands or leathers upon each step that the separate steps of
the special piston are in different chambers. The smallest part of the special piston
works in a chamber which is in a direct communication with the high pressure
supply, and supposing there to be only a small load upon the lift or crane then the
high pressure upon the smallest area of the special piston would cause sufficient
movement and pressure upon the large end of the special piston to produce enough
pressure in the lift cylinder to cause the lift to rise. The chamber in communication
with the lift cylinder is connected with the intermediate chambers of the special
piston and valves are applied in such a way that the pressure in the lift cylinder
itself determines whether the high pressure water shall act only upon the smallest
part of the special piston or upon that area and one or more annular areas due to
the stepped form of the special piston.
In this arrangement it is obvious that the load which is to be lifted itself deter-
mines the quantity of high pressure water which is used by the apparatus.
It is to
be noted that all the intermediate chambers in which the special stepped piston works
are always full of water from the exhaust. The number of the steps upon the special
piston will be determined for each case separately and it is clear that with three
steps for example three different lifting powers are obtained with the same efficiency.

page_text: The diameters of the stepped piston will be relatively large as compared with the
diameter of the lift ram in order that the stroke of the special piston may be
relatively short.
Dated this 2nd day of January 1893.
JOHN P. O'DONNELL,
70 & 71, Palace Chambers, Bridge Street, Westminster, S. W.,
Agent for the said Applicant.
COMPLETE SPECIFICATION.
Improvements in Hydraulic Machinery.
1, CHARLES CHRISTIANSEN of 35, Calthorpe Street Gray's Inn Road, in the
County 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 relates to a high pressure fluid supply regulator which to a certain
extent regulates the quantity of high pressure fluid consumed by the machinery
such as lifts cranes or other pressure fluid machines or motors to the amount of work
they have to perform.
In order that this invention may be properly understood reference is made to the
annexed drawing which illustrates this invention arranged for working loads within
three limits and in connection with a lift where it is placed in such a manner that
pipe a is the pressure fluid supply pipe which supply regulated by an ordinary
slide or any other known controlling valve which alternately admits the pressure
fluid or lets the used pressure fluid exhaust and closes both the supply and exhaust
which causes the lift to remain stationary.
Pipe b forms a direct communication with the cylinder of the lift and as this and
the chamber A is always full of water or any other fluid this fluid is under a
pressure corresponding with the load placed upon the lift.
Steps B C and D form a step piston or plunger and B is of such dimensions, that
its comparatively short travel in direction of the arrow will displace enough fluid to
force the lift upward to the full extent.
When the supply is turned on chamber F is always open to the pressure fluid
which acting on D is able to push the whole plunger forward thereby raising the
lift when the load on the lift does not exceed the smallest limit. But as will be
seen the quantity of pressure fluid consumed is only that which was necessary to
displace the travel of step D instead of consuming enough pressure fluid to displace
the whole travel of the lift ram as would have been the case without using this
invention. When the controlling valve is closed to the supply and opened to the
exhaust the lift will descend thereby raising the step plunger and the used pressure
fluid will exhaust through pipe a.
Step C in chamber E is of such dimensions that when the pressure fluid is
admitted to chamber E and acts on the annular ring of C in addition to the pressure
acting on D it is able to push the plunger forward thereby raising the lift when the
load on the lift does not exceed the middle limit, but only using the quantity
of pressure fluid necessary to displace C instead of consuming the whole quantity
necessary to displace the whole travel of lift ram as would have been the case
without using this invention. The pressure fluid is admitted to chamber E as
follows: The pressure of the fluid in chamber A varies with the loads placed on
the lift and acts through pipe c on the end of the valve spindle d which is weighted
by the lever and weight for any other suitable means in such a manner that
should the load on the lift exceed the smallest limit, but not before and also does
not exceed the middle limit it forces the valve spindle upwards thereby raising the
lever and weight f until the lower part of the slot in connecting rod g reaches
the lever and weight which or any other suitable device prevents the spindle d
rising higher.

page_text: To the spindle d are attached the valves i. k. l. m. which are here shown as piston
valves, but which however might be of any other suitable form. Valves ik l m
work in valve chamber p the upper end of which is connected by pipe n to
chamber E while p¹ is connected by pipe o with the exhaust or any tank in such a
manner that while valve i is in the enlarged part of p and has not yet entered pl
chamber E will be always full of exhausted fluid. Assuming a load exceeding the
minimum limit but not exceeding middle limit is placed on the lift the spindled with
valves i. k. I m will rise as previously described, and valve i will enter p' first thereby
closing the exhaust through o and then valve k will leave p and enter the enlarged
space thereby allowing the pressure fluid to enter through pipe a' which is part of
pipe a and through pipe n, into chamber E where it will act on C as described.
Should the controlling valve in connection with a then be closed to the supply and
opened to the exhaust the valve spindle with valves i k l m will return to the
position as shown while the lift descends, thereby raising the step plunger and
expelling the exhaust fluid in chamber E through n p' and o.
Should the load placed on the lift exceed the middle limit the pressure of the
fluid in chamber A will be correspondingly higher and will after raising the valve
spindle d with weight and lever fattached to it until the lower part of the slot in
the connecting rod g has reached lever and weight h, raise the latter also whereupon
the travel of the valves i k l m will have been as follows:-First i will enter pl
thereby closing the exhaust from chamber E then k will enter the enlarged space
of p while will pass the pipe a¹ thereby closing chamber E entirely and
preventing any upward movement of the plunger BCD and also allowing the
pressure fluid to pass from a' into pipe and through the non-return valve into
chamber A where through pipe bit will act direct on the lift ram and the full load
can now be raised by using the same quantity of pressure water as would be the
case without the use of this invention. Should the controlling valve in connection
with a then be closed to the supply and opened to the exhaust, the valves i k l m
will return to the position as shown while the used pressure fluid will exhaust
through the non-return valves and along pipe a.
If however a load exceeding the smallest or middle limit was placed on the lift
while it was half or any way up and the plunger B. C D correspondingly down the
used pressure fluid would not exhaust through valve s owing to its being weighted
with lever and weight t but would first raise the plunger B. C. D to the top of its
stroke whereby part B would through the connecting rod u release the valves and
allow the used pressure fluid to escape by it.
Should the plunger B C D reach the bottom of its travel before the lift has
ascended sufficiently high I attach to part B a nose or catch v which when the
plunger B C D is nearing the bottom of its stroke engages with the projecting end
of the lever and weight h thereby raising them and the valve spindle with the
valves i k l m when the fluid pressure is admitted to chamber A as previously
described and the pressure fluid then acts direct on the ram of the lift.
By using any number of steps on the step plunger a corresponding number of
limits between which the loads on the lift may vary with a given consumption of
pressure fluid can be obtained.
This invention as described here in connection with a lift will be suitable for use
with any other pressure fluid machinery and motors.
By making the plunger B. C D of a proportionate weight to the ram and cage of
the lift this invention can also be used as a counter-balance.
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:
1st. The construction and combination of an auxiliary step piston or plunger of
any number of steps working in a casing with a separate chamber for each step,
placed between the pressure fluid supply and the machine or motor to be worked,
the said step piston or plunger being of such a construction that its largest end will

page_text: displace the quantity of pressure fluid necessary for one operation of the machine
or motor to be worked and the chamber in which the said largest end works to be in
direct communication with the said machine or motor while the chamber in which
the smallest end works is in direct communication with the pressure fluid supply
substantially as set forth.
2nd. The combination of the said step piston or plunger and chambers and a valve or
valves loaded by levers and weights or other suitable means, and channels or pipes
communicating with the separate chambers and such valve or valves to be worked
automatically by the pressure of the fluid in the largest chamber which varies with
the load put on the machine or motor thereby admitting or exhausting pressure
fluid substantially as set forth.
3rd. The combination and arrangement of valves and levers or other suitable
devices in such manner that should the said step piston or plunger have reached
the end of its travel before the operation of the said machine or motor be completed
that the pressure fluid shall be admitted direct to the said machine or motor
substantially as set forth.
4th. The arrangement of the step piston or plunger in such manner that it may
be used as a counterbalance to a part or parts of the said machine or motor
substantially as set forth.
Dated this Second day of September 1893.
CHARLES CHRISTIANSEN.