Improvements in Hydraulic Elevators, Lifts, and the like.
Year: 1892

page_text: Date of Application, 27th Dec., 1892-Accepted, 28th Jan., 1893
COMPLETE SPECIFICATION.
Improvements in Hydraulic Elevators, Lifts, and the like.
I, THOMAS FITCH ROWLAND, of 329 Madison Avenue, in the City, County and
State of New York, United States of America, Manufacturer, 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 :-
The present invention relates to that class of hydraulic machinery which is
employed to lift loads of various kinds, the form of mechanism selected to illustrate
the application of the improvements being a hydraulic accumulator; but it is to be
understood that the improvements are applicable to many other forms of hydraulic
elevators, lifts or rams. The accumulator, as shown in the present case, is one
adapted to put a fluid such as water under very high pressure, and to supply the
same to a hydraulic guu-lift mechanism, one form of which mechanism is shown
and described in an application for Patent filed and pending contemporaneously
herewith.
One object of the invention is to provide improved means whereby the load on
the ram or travelling member of the accumulator, can be easily landed or brought
to rest without injury to the machine, particularly in event of the rupture of the
connecting pipes, or the occurrence of such other break or derangement of the
parts as would permit the fluid in the ram cylinder to escape.
It is also the object of the invention to provide an improved coupling for
attaching the fluid conducting pipes to the ram or its cylinder.
And further, the invention relates to improved guide and controlling devices
whereby the load on the moving member of the accumulator is confined to the
desired path of motion.
The mechanism of the drawings will be described in detail, and in the claims
to follow the description, I will point out the features of invention that I claim
as new.
Fig. 1 is an elevation view of a hydraulic accumulator embodying my improve-
ments, the plunger and cylinder being shown in central vertical section, this type
of machine being one in which the travelling member is a cylinder moving along
and over a fixed plunger or ram; and in this view the cylinder and plunger aro
shown in their extended position, that is, in that position where the load
upper limit of its path of movement.
at the
Fig. 2 is a central vertical section of a hydraulic apparatus in which the cylinder
is fixed and the plunger or ram moves vertically therein and carries the load.
Fig. 3 is an enlarged detail central sectional view of the lower end of the cylinder
and ram shown in Fig. 2, the valve mechanism thereof being shown in central
vertical section.
Fig. 4 is a view similar to Fig. 3, but showing a modified construction of valve.
Referring to Fig. 1, 1 represents the base of the apparatus; 2 is the hollow
plunger fixedly attached to the base; 3 is the cylinder moving on the plunger;
4 is an inlet, and 5 is an outlet pipe; and 6 is a platform carried on the cylinder
and upon which is carried the load 7, in this case shown as a series of heavy blocks
of metal. The upper end of the cylinder is closed, and the cylinder is provided
with any suitable packing devices whereby tight joints are made between it and
the plunger, and, in other respects, the general construction of the apparatus is in
accordance with the well known methods.
It is to be understood that this form of apparatus is intended to serve to produce
an artificial head to the water, that is, to put it under high pressure, and to

page_text: maintain a constant and steady pressure, of a thousand pounds or more to the
square inch in some cases. Thus the pipe 4 may be considered as connecting with
the pumps designed to force the water into the accumulator, and the pipe 5, as
leading to the machinery to be operated by the water under pressure. But the
same character of plunger and cylinder can be employed to lift ordnance or heavy
projectiles, passenger cars and any form of loads where the conditions are adapted
to the employment of hydraulic apparatus.
At the upper end of the cylinder is the valve cage 8 in which is disconnectedly
hung the plug valve 9. This cage is of a hollow cylindrical form, and is secured
in or at the upper end of the cylinder by proper connections. The lower end of
the cage has a flange opening 10 in which hangs the valve 4, the body part of
which is somewhat smaller than this opening, while the head of the valve is smaller
than the interior bore of the cage, so that the valve is suspended in the opening by
its head engaging the flanged head of the same. This valve is free to move
vertically in the cage, and when its head is off the supporting flange, water can
pass freely around the valve into or out from the cage. The body 9 of this plug
valve is cylindrical in form, and this cylindrical portion is of a length corresponding
substantially to the vertical extent of the bore or hollow of the cage. From the
lower end of the body of the valve projects the coned plug point 11, which point is
smaller in its largest diameter than the body of the valve, thus producing a
shoulder 12 between the body and point.
13 is the valve seat, which seat is properly secured to and in the upper end of
the piston 2. The size of the seat opening is slightly larger than the greatest
diameter of the point of the valve. The valve and valve seat are arranged
centrally to and on the axial line of the piston and cylinder.
It will now be plain, that, as the load descends and as the upper ends of the
plunger and cylinder approach, the plug point of the valve will enter the valve seat
and gradually close the same, thus trapping a body of fluid between the plunger
and cylinder. It is to be understood, however, that such a valve, under the
pressure exerted by the load common to this class of machinery, is rarely if ever
absolutely tight as to its fit in its seat, and, further, that there will nearly always
be some lenk between the piston and cylinder. Accordingly, after the load has
been retarded, or brought as nearly to rest as the tightness of the parts will permit,
the further slow escape of the water from between the cylinder and piston will
permit the cylinder to slowly descend and very gradually come to absolute rest on
the piston. In this way, the load is landed without danger of the cylinder and
piston coming into violent contact and thereby breaking or otherwise injuring
the parts.
In this latter connection, it is to be noticed that the valve has no positive
connection or attachment with the cylinder, and that when it strikes the valve seat
and the full flow of water through the seat is cut off, the further motion of the
cylinder cannot be transmitted through the valve to the plunger, since the valve
cage is free to move vertically along the valve.
"It
may be desirable in such cases to construct the valve smaller than the valve
seat, or to score or groove the valve, or otherwise to construct the parts so that
the escape of water from between the piston and cylinder can be defined and the
landing of the load regulated as to time. To this end I construct the disconnectedly
hung valve 14, as shown in Fig. 2, where the valve is carried on the lower end of
the plunger, being loosely hung in a suitable orifice 15 therefor, a cage 16 being.
provided to prevent the valve leaving the hole in the plunger, but permitting its
proper vertical movement. The seat 17 of the valve is formed in the lower end of
the cylinder, or in that portion of the base 1 which closes, the lower end of the
cylinder. This valve is perforated through its coned point by the passage 18,
which extends from the end of the valve upwardly and then out laterally (see
Fig. 3) in such manner that when the valve is on its seat this passage will
communicate between the cylinder and the space below the valve seat.

page_text: In Figure 4 the valve is exteriorly grooved at 19, whereby surface passages
are formed therein, extending from above the valve seat to below the same, when
the valve is seated. Other ways of producing such a passage, or such a similar
passage will occur to those skilled in the art.
It will now be plain that upon the descent of the plunger and just before it
arrives at the limit of its downward movement the valve will enter and close its
seat the same as in the case of Fig. 1, thus cutting off the full flow of the water
Such of
through the valve seat and gradually bringing the plunger nearly to rest.
the fluid as now is trapped above the valve seat will have final graduated escape
through the passage or passages in the valve, and thus the plunger will be slowly
landed, and without shock as it comes to rest upon the base of the apparatus. By
these means, also, the time of the landing of the pistou and its load can be made
uniform and of such duration, dependent upon the size of the passages through
the valve, as is found best suited to the proper action of the apparatus.
20 represents tubes seated in the platform 6 and extending vertically through
holes in the inner periphery of the weights 7. These tubes serve to hold the
weights from shifting circularly upon each other. 21 represents guide rods for
the load of weights, and they are firmly anchored to the base 1, pass through the
platform 6, and have at their upper ends heads 22 of a diameter about the same
as that of the bore of the tubes 20, and larger than that of the rods or the holes
for the rods through the platform.
These rods serve as guides to the load, and also to prevent the cylinder 3 being
accidentally carried so bigh as to run off the plunger, and therefore to permit the
load to topple and wreck the apparatus by falling. Thus, if the cylinder rise too
high, the heads on the guide rods will engage the platform and arrest the load; it
being understood that the power of the pumps serving the accumulator is not so
much in excess of that necessary to lift the load but that the lifting action is easily.
resisted by the guide rods. This guide mechanism, however, is not the only"
mechanism provided for controlling the load; it is employed as an emergency
protection to answer to possible but not usual conditions.
.
It is found in the use of this kind of apparatus, and especially when the pressure
is very high, that the water cuts away the pipes and other passages, and so makes
leaks or ruptures of the parts a constant source of danger. This tendency
naturally occurs at points in the water passages where the deflection is the greatest
and where variation of current is most pronounced. One such point, and the one
to be most guarded is where the inlet and outlet pipes are attached to the
apparatus.
To overcome this difficulty, I pierce the plunger 2 or the base 1 with plain holes,
for the pipes 4 and 5, which holes are outwardly enlarged or socketed at 23 to
receive the pack flange 24 of a common form of packing ring 26, and I provide
each of the pipes with a collar 27 threaded on the end of the pipe and fitting the
outer packing socket. The pipes 4 and 5 are inserted so as to project into the
plunger 2 or base 1 beyond the face of the inner walls of the same.
By these means, as the inner ends of the pipes are cut away, the collars 27 can
be set further back so as to ensure the ends of the pipes always projecting well into
the plunger, and so far beyond the walls of the same as to prevent the water cutting
into the walls and weakening them.
I am aware that various forms of valves have been proposed for hydraulic
apparatus that are adapted to gradually shut off or close an inlet or outlet port,
and I do not claim such. My invention relates to a plug or similar valve carried
without positive attachment or operating connection on the moving piston or
plunger or on the moving cylinder of an hydraulic apparatus, such valve being
arranged to close the water passage or port leading to within the cylinder and
to cut off the full escape of the water as the moving part is being landed on
the stationary part or member.

page_text: 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. In combination, a hydraulic cylinder and the plunger or piston thereof, one
movable in or over the other, a valve disconnectedly carried on the moving
member and an open valve seat on the fixed member arranged in line with the
valve, whereby, as the moving member descends upon or in the fixed member a
body of fluid will be confined between them and the moving member be thereby
retarded and finally gradually brought to rest upon the fixed member without
shock.
open
2. In combination with a hydraulic cylinder and the plunger thereof, a movable
coned valve disconnectedly carried on the cylinder or moving member, an op
valve seat on the plunger or stationary member arranged in line with said valve,
whereby as the cylinder descends upon the piston the escape of the fluid from
between the two members is retarded and the movable member caused to come to
rest upon the stationary member without shock.
3. In combination, the hydraulic plunger 2 and the cylinder 3, a plug valve
disconnectedly hung in a valve-enclosing cage on the cylinder, a valve seat on the
plunger arranged to receive the said valve as the plunger and cylinder close
together, substantially as and for the purpose set forth.
4. In combination, a hydraulic cylinder and the plunger or piston thereof, a
valve disconnectedly carried on the piston or moving member, an open valve seat
on the cylinder or stationary member arranged in line with the valve, whereby as
the piston descends in the cylinder, a body of fluid is confined between them, and
a duct or channel adapted to permit the slow escape of the trapped water from
between the plunger and piston and thereby cause the plunger to come gradually to
rest without shock.
5. In combination, with a hydraulic cylinder and the plunger thereof, a valve.
disconnectedly carried on the moving member, an open valve seat on the stationary
member in line with the valve, and a port or passage to establish communication
between the space above the valve seat and the space below it, substantially as and
for the purpose set forth.
6. In combination with a hydraulic cylinder and the plunger thereof, a valve
disconnectedly carried on the moving member, an open valve seat seat on the
stationary member arranged in line with the said valve, the said valve being
provided with a duct or passage adapted to permit the slow escape of water by the
same after being seated in the valve seat, substantially as and for the purposes set
forth.
7. In combination in a hydraulic accumulator, the plunger 2 and the cylinder 3,
the platform 6 carried by the cylinder or moving member, the tubes 20 holding the
weights 7 in position upon the platform, and the headed guide rods 21 arranged to
limit the upward movement of the platform, substantially as and for the purpose set.
forth.
8. In combination with the plunger or cylinder of a hydraulic apparatus, the
socket pipe hole 23, the pipe 4 having its end threaded and extending through the
wall of the cylinder or base 1, the threaded collar 27 adjustable on the pipe 4, and
the packing ring 26, combined and operating substantially as and for the purpose
set forth.
ated this 27th day of December 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.