IMPROVED APPARATUS FOR REGULATING THE PRESSURE OF WATER SUPPLIED TO HYDRAULIC HOISTS to be as follows
Year: 1884

page_text: CANAL DECIFICATION.
I, JAMES JOHN MILLER, of Creek Works, Hammersmith, in the County of
Middlesex, Engineer, do hereby declare the nature of said invention for "IMPROVED
APPARATUS FOR REGULATING THE PRESSURE OF WATER SUPPLIED TO HYDRAULIC
HOISTS to be as follows:-
"
The object of my invention of improvements in hydraulic lifts is to enable the
pressure to be adjusted to suit the work to be done. For this purpose I cause the
pressure in the accumulator or main to actuate an engine, the plunger of which
I connect to a plunger working in another cylinder this second plunger being
employed to produce the reduced or increased pressure through a greater or less
distance required to raise the load or perform the work.
The connection is in the form of a lever or lovers or the equivalent thereof with
an adjustable fulcrum-so that by shifting the fulcrum the relative strokes of
plungers or pumps and corresponding pressures can be adjusted as required.

page_text: COMPLETE SPECIFICATION.
I, JAMES JOHN MILLER, of Creek Works, Hammersmith in the County of
Middlesex, Engineer, do hereby declare the nature of my invention for "IMPROVED
APPARATUS FOR REGULATING THE PRESSURE OF WATER SUPPLIED TO HYDRAULIC
"1
HOISTS 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 of improvements in hydraulic lifts is to enable the
pressure to be adjusted to suit the work to be done. For this purpose I cause the
pressure in the accumulator or main to actuate an engine, the plunger of which
I connect to a plunger working in another cylinder; this second plunger being
employed to produce the reduced or increased pressure through a greater or less
distance required to raise the load or perform the work.
The connection is in the form of a lever or levers or the equivalent thereof with
an adjustable fulcrum so that by shifting the fulcrum the relative strokes of
plungers or pumps and corresponding pressures can be adjusted as required.
In the accompanying sheet of illustrative drawings Fig 1 is a side view of
apparatus embodying my invention and Fig 2 is a view at right angles thereto.
Fig 3 is a detached view of the lever and means for shifting its fulcrum shewn in
Figs 1 and 2, and Fig 4 is a similar view of a modification. a is the engine or
cylinder the piston or plunger b of which is actuated by the fluid pressure in the
accumulator or main. c is the engine or second cylinder for producing the reduced
or increased pressure and d is its piston or plunger in the form of a trunk. e is a
casting or frame carrying the engines or cylinders a and c. The plungers b and d
are connected through their rods b and d with the opposite ends of the lever or
beam the fulcrum g of which is adjustable and works in a sloth formed in a
frame i when the lever is actuated by the rod 6. The adjustment of the fulcrum g
may conveniently be effected by means of a screw j which when rotated by the
handle causes the fulcrum g to slide in the slot f¹ in the lever f to any desired
extent, the length of the two arms of the lever being thus varied according to
requirements.
In the modification shown in Fig 4 the adjustment of the fulcrum g in the lever
slot is effected by the plunger rod or rods k of a fluid pressure cylinder or
cylinders carried by the lever f. The plunger rod b¹ is guided by extensions of
the pin m which connects it to the lever fand which work in longitudinal grooves
or recesses m¹ formed in the frame i. n is a pin connecting the plunger rod d¹ to
the lever f, the said rod working on a pin within the trunk plunger & as a centre
when the lever fis operated. It will be readily understood that if the adjustment
of the fulcrum g be such that the length of the lever arm g. m is shorter than the
arm g. n, the plunger d will transmit a reduced pressure through a greater distance
to liquid employed to raise loads or perform other work than would be the case if
the plunger bacted directly upon such liquid, whilst if the arın g. m be longer than
the arm g. n then the plunger & will transmit a greater pressure through a less
distance than that of the plunger b. Thus the pressure of the water supplied to
hydraulic hoists, may be,regulated or adjusted at will,

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
•
In apparatus for regulating the pressure of liquid supplied to hydraulic hoists
1. The use in combination with an engine or cylinder and piston or planger (or
cylinders and pistons and plungers) to receive liquid pressure and an engine or
cylinder with piston or plunger (or cylinders with pistons or plungers) to transmit
such pressure, of a lever or levers the arms of which are unequal substantially as
described for the purpose specified.
2. Providing the lever or levers referred to in claim 1 with an adjustable fulcrum,
or fulcra, substantially as described for the purpose specified.
3. The combination and arrangement of parts constructed arranged and operating
as described with reference to and shewn in Figs 1, 2 and 3 or modified as
illustrated in Fig 4 of the drawings for the purpose specified.
Dated this 4th day of March 1885.
JAMES JOHN MILLER.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C.,
Applicant's Agent.