Improvements in Machinery and Apparatus for Hoisting and Lowering People and Goods.
Year: 1894

page_text: Date of Application, 17th Jan., 1894-Accepted, 5th May, 1894
COMPLETE SPECIFICATION.
Improvements in Machinery and Apparatus for Hoisting and
Lowering People and Goods.
I, CHARLES ARTHUR ALLISON, of 52 Chancery Lane, London, in the County
of Middlesex, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by Benjamin T. Lacy, of San Francisco,
in the State of California, United States of America, Engineer and Merchant), 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 machinery for hoisting and lowering, commonly called
elevators, operated by fluids under pressure, elastic or inelastic, or both combined,
and especially to balancing, compensating and equalizing the forces set up in such
machinery, and to the control of the actuating fluids by valves, ducts and containing
chambers.
The invention consists of various mechanical expedients adapted to, and covering,
the diversified uses and conditions under which such machinery has to be erected
and operated, including the arrangement of the hydraulic apparatus of such
elevators, so that the water displaced by the descending cages or platforms will be
forced upward to a height corresponding to the stroke of the hydraulic piston, and
sufficient to counterbalance the gravity of the cages or platforms to any desirable
extent, thus avoiding the use of suspended counterweights and their connected parts,
such as are commonly employed.
One such method of construction is shown in Fig. 1 of the drawings.
Also in connecting the two ends of the main actuating cylinder so that on the
downward movement of the cage the impelling fluid will pass from one side of the
piston to the other, except so much as is required to balance the cage; this portion
being forced back to the source of supply to be utilized on the return or lifting
movement, and applicable to hydraulic cylinders in which the piston performs its
principal work on its outward stroke. This arrangerment is shown in Figures 2 and 3
of the drawings.
Also in the employment of a constant pressure of water resting on and pressing
upon both sides of a hydraulic piston, when the latter is not acting, but with
different force. This pressure being removable from one side thereof by means of
suitable valves, that on the other side then acting to perform the desired work,
and so that when this work is performed, or a load is raised, the static pressure on
each side of the piston is resumed, and the descent of the cage or platform, and
return stroke of the piston, is produced by so much of the gravity of the former as
is required for that purpose. This arrangement is shown in Fig. 4 of the drawings.
Also in the employment of separate water connections to the two ends of the
hydraulic cylinders, one leading to a storing tank, from which no water is consumed,
but only circulated, the other connection being to a supply tank or source from
which is drawn a weight of water equal to the loads raised by the elevator, less
friction or other resistances common to this class of machinery. The other pipe
leading to a supply tank at a lower level, from which water is consumed in
proportion only to the service load that is raised. This arrangement is shown in
Fig. 4 of the drawings.
Also in connecting one end of the hydraulic cylinder, or one side of the piston
thereof, constantly with the impelling water, permitting a free circulation to and
from the source of supply, under pressure; the area of the piston and the pressure
thus derived being sufficient to raise the maximum load required, such force being

page_text: opposed on the opposite side of the hydraulic piston, by the weight of the cage and
its attachments, commonly called dead weight, and also by water pressure from the
supply source, the latter reduced by an enlarged piston rod, the area of which,
multiplied by the pressure, represents the dead weight of the cage, less the amount
of force required to overcome friction. This arrangement is shown in Fig. 5 of
the drawings.
Also consists of apparatus whereby the circulation of the impelling fluid through
supply and pressure tanks, and the cylinder of the hydraulic apparatus is performed
in such manner that on the return stroke of the latter any force from a pre-
determined descending load, acting oppositely to the water pressure, will force the
spent water into a second tank or receiver against a yielding pressure, which pressure
can be again transferred to the main hydraulic supply tank and utilized in the
subsequent working of the hydraulic apparatus, so the duty performed by the
motive power will be only that due to friction, and the service loads raised. This
arrangement is shown in Fig. 6 of the drawings.
This invention also includes a float moving in a vessel connected to the receiver,
containing a supply of elastic fluid under pressure, so that when the water therein
falls below a certain point in the receiver the float descends at the same time with
the escaping water, and by indication shows how much water remains in the
receiver, and, at some predetermined point, brings into contact two electrodes so as
to form an electric circuit, and ring a gong or bell, and thus give audible, as well as
visual, notice of danger by reason of the receiver being empty, or the water so low
as to permit the escape of steam or air to the hydraulic cylinder. This part of
my invention is shown in Fig. 7 of the drawings.
My inveution finally includes balanced piston valves to control the distribution
and flow of water for elevators, adaptable to various modifications, uses and
arrangements included in this invention, as shown in Figures 8 and 9, and will
be hereinafter more fully set forth and described in connection with the drawings
thereof.
The main objects to which this invention is directed are to dispense with the
usual counterweights employed to balance cages, platforms or any kind of dead
weight in the operating parts, and to provide for the varying weight of the chains
or ropes, the suspended length and consequent weight of which varies as the load
ascends or descends.
Also to utilize the weight of the descending cage by forcing back thereby, against
the acting pressure, an equivalent amount of water to the source of supply, to be
again used when the cage ascends and to avoid counter balancing weights such as
are usually applied to elevator cages.
Also to compensate in this manner any constantly-acting resistance to the
hydraulic piston other than its average required duty, such as the weight of cages,
platforms, ropes of elevators, or other load acting with the back or return stroke of
the hydraulic piston.
Also to attain other desirable objects conducing to economy, safety and a more
efficient performance of machinery of this class.
In referring to the drawings, which will now be referred to, the letters of
reference are independent on each figure, and the notation in the Specification is
made to indicate figures as well as the letters of reference thereon.
Referring first to Fig. 1:
It represents a common elevator, having a cage or carriage A moving between
two guiding posts B', B³, by means of a rope or cable C, to which the cage is
suspended. This rope or cable C is connected to and operated by a hydraulic
cylinder D, having a piston rod E, with a pulley or pulleys F at the top. The
rope or cable C is fastened to the shackle a, passes around the pulley F on the
piston E, thence around the guiding pulleys G¹, G³, at the top, and is attached to
the cage A as shown, causing the cage A to move twice as far as the piston E, but
this relative movement of the cage and piston can be arranged at will by the
number of pulleys or sheaves interposed, and to meet the requirements in any case.

page_text: This method of gearing being well understood, and the drawing mainly to show my
method of counterbalancing, further description of the rope C and its gearing is not
required.
The hydraulic cylinder D, which can be placed either vertically or horizontally,
is of the usual construction, having a close-fitting piston, and may be open on the
bottom if desired, the water being admitted on the top only of the piston. This
far the machinery, and all parts mentioned, correspond to common practice in
constructing such elevators.
To compress the water in the cylinder D, and supply power to raise the cage A,
I employ, by preference, an elastic fluid, steam or air, controlled by valves moving
simultaneously with those that control the flow of the water.
At some point above the hydraulic cylinder D is placed a vessel H called a
receiver, the cubic capacity of which, to some extent, exceeds that of the hydraulic
cylinder D, its diameter corresponding to or varying from that of the main
cylinder D as the height to which the water raised therein may require.
Connecting to the top of the receiver H is a pipe I which leads to a steam
boiler J, as shown in the diagram, or some other initial source for supplying air or
steam under pressure. At L there is a valve which in one extreme position admits
steam from the boiler J to the top of the receiver H, and in the other extreme
position exhausts the steam from the receiver to the atmosphere, and acts as a stop
valve, preventing flow in either way when in its central or neutral position.
At M there is another valve that controls the flow of water from the receiver H to
the hydraulic cylinder D through the pipe V and also the reverse way, but so
constructed that when closed in either direction there is a free flow back, in other
words, the valve closes in one direction only and opens automatically in the other
direction if there is a superior pressure in the vessel to which the valve opens. To
operate these valves L and M there is a cord or rope O passing over the pulleys e, e,
at the bottom, and pulley P at the top. On the axis of the pulley P are two
smaller pulleys or wheels T, over which pass chains Q', Q', to the pulleys or
wheels R and S, which operate the valves L and M. The rope O has stops m, m,
that cause the valves L and M to close automatically at the extreme upper and
lower stroke of the cage A, and these valves are reversed to change the course of
the cage A from its interior in the usual manner.
It is customary in constructing elevators to compensate partially the difference in
weight between the cage A and the piston carried by the rod E by means of
counterweights commonly suspended on ropes passing over pulleys, leaving,
however, enough excess in favor of the cage A to cause it to descend without
a load.
In the present case counterweights are dispensed with by placing the receiver H
at some position above the hydraulic cylinder D, the operation being as follows:
Supposing the cage A to be in the position shown in the drawing, or at the top
of its range or stroke, and the piston in the hydraulic cylinder D to be at the
bottom of its stroke, then this cylinder D will be filled with water expelled from
the receiver H, and replaced by steam from the boiler J. Then suppose the
valves M and L to be reversed so that the steam in the receiver H will escape to
the atmosphere, and the water in the cylinder D be forced back into the receiver H
as the cage A descends. Now if the cylinder D and receiver H are of approximately
the same diameter, or so proportioned as to compensate for unbalanced forces, the
weight of the water thus discharged therein will offer a constant resistance to the
descent of the cage A, proportioned to the height of the receiver H above
the cylinder D. In this manner I am able to counterbalance the cage A to any
desirable extent and uniformly at all points of the stroke by the relative positions
of the receiver H and the hydraulic cylinder D, and without providing therefor
any mechanism or operating detail whatever, also avoiding the wear, danger of
derangement, and expense of providing counterbalances. The amount of the
counterbalancing force is dependent on the height of the receiver H above the
cylinder D.

page_text: The diameter of the receiver H is made with some definite relation to that of the
main cylinder D, approximately the same, if the weight of the winding ropes or
chains is not considered, and when the cylinder D is set in a vertical position, but
as these latter are often long and heavy, a variable or progressive counterforce is
required in balancing.
In such cases it will be understood that the height to which the water rises in
the receiver H will be due to its diameter, and that by varying this a constant or
varying dead weight can be compensated accordingly.
Referring next to Figures 2 and 3:
Fig. 2 is a longitudinal view, partially in section through the main hydraulic
cylinder; also the manner of connecting the cage and main hydraulic cylinder.
Fig. 3 is a transverse section through a common valve or cock to distribute the
water.
The main cylinder A is of the usual construction, having heads B', B', with a
stuffing box and gland C in the head B' where the piston rod D passes through.
The piston E moves back and forth between the ports F1, F2, where the water enters
and leaves the main cylinder. G is the inlet pipe connected with water under
pressure, and H is the outlet or exhaust pipe through which the waste water
escapes. R is a distributing valve or cock connecting the two ends N', N³, of the
main cylinder, also connecting the end N' with waste pipe H when set in the
position shown in Fig. 3.
I do not confine myself to the particular kind of valve or cock here shown, but
employ any
modification that has the required functions, as will be more fully
explained in a future place.
L, L, are multiplying sheaves or pulleys around which passes a rope M a
sufficient number of times to determine the relative movement of the piston E and
the cage O, to which the rope M is led over the two idle pulleys P1, P². T',T', are
the usual guide posts to direct and sustain the cage O.
The sheave or pulley L is attached to the head B' of the cylinder A, the axis
being fixed. The other pulley L' is attached to, and moves with, the piston rod D
and piston E, in the usual manner of constructing such gearing.
The manner of operating is as follows:
Supposing the cage O is to descend as indicated by the arrow in Fig. 2, and the
valve or cock R, is in the position shown in Fig. 2; both sides of the piston E are
then exposed equally to the pressure of the fluid entering by the pipe G, and the
piston is forced inward by the weight of the descending cage. The water in the
cylinder A is then free to circulate from the chamber W to the chamber Q, and
from one side of the piston E to the opposite side, as indicated by the arrows in
Fig. 2, but the chamber Q being reduced in volume by displacement of the piston
rod D equal to its cubic contents, all the water in the chamber W cannot pass into
the chamber Q, and a portion equal to the volume of the piston rod D is forced
back through the pipe G, to be again utilized when the opposite or lifting motion
of the cage takes place, and the movement of the piston E is reversed.
When the cage O' is to be raised, the valve or cock R is turned to the position
shown in Fig. 3, opening communication between the chamber Q and the waste
pipe H, relieving the piston E of pressure on one side, and subjecting its whole area
on the other side to full force of the impelling fluid in the chamber W. The cage
then rises with a force equal to that of the impelling fluid on the piston E, in the
proportion of their relative movements.
On the descent of the cage, or at all times when there is free communication
between the chambers Q and W, and to each side of the piston E, there is an out-
ward thrust on the piston rod D equal to the area of its section multiplied into the
operating pressure in the supply pipe or the main cylinder, such pressure serving
to sustain the cage O. The counterbalancing pressure can be adjusted to any
degree by increasing or diminishing the diameter of the piston rod D accordingly.
Thus it will be seen that while there is used on the upward or lifting movement
a greater amount of water than would be required if the cage was balanced in the

page_text: usual way, there is no loss whatever, because the water forced back into the supply
is again used in the succeeding upward or lifting movement of the cage, and th.
only loss is that of the power absorbed by friction of the machinery.
Referring next to Fig. 4:
The drawing is a side elevation of the main operating elements of a common
elevator arranged with my improvements, the hydraulic cylinder being partly in
section.
A circulating tank D is set at such height above the hydraulic chamber A, and
the piston B is made of such diameter that the pressure in the chamber A and
against the piston B, when unopposed, will raise the required load C at a pre-
determined speed. The water contained in this tank D is not changed but remain.
the same in volume, circulating up and down in the pipe J, between the chamber a
of the hydraulic cylinder and the tank D, as the piston moves backward and
forward in the cylinder.
The tank E is set at a lower level than the one D, so the gravity or pressure of
water from the power will press upon the piston B with a force which, supplemented
by the weight of the cage C, will exceed the pressure in the other end of the
cylinder from the tank D, to the extent of the friction of the moving parts of the
machinery.
In practice the relative elevation and pressures from the two tanks E and D are
approximately in proportion to the dead and service load of the cage C, including
the resistance of friction for both the water and mechanism.
The operation is as follows: Supposing the cage or weight C is to be raised, and
the chambers a and c of the cylinder are both filled, the one a sustaining a static
pressure due to the head of water in the tank D, the pressure on the other side of
the piston B, being equal to the pressure from the tank E, supplemented by the
weight of the cage C acting on the piston rod N. The valve L is closed,
preventing the water from descending in the pipe K, and the one Q is opened,
permitting its escape from the chamber c through the pipe M. This relieves the
piston B from pressure on the side next the chamber c, and the pressure on the
other side from the tank D, then acts with full force on the piston B, rod N, and
the sheave wheel G, thus raising the cage or load C.
When the cage C has reached its extreme upper stroke, or is to be stopped at
any point on the way, the valve Q is closed, and the piston rests against the
entrapped water in the chamber c.
To descend, the valve L is opened and connection is established with the supply
tank E. This pressure in conjunction with that of the weight of the cage pressing
on the piston rod N, places the pressure on the pistou B in equilibrium, except as to
the allowance for friction, before explained; this acting on the rope F, sheaves G
and H, and the piston rod N, forces the piston B back, sending the water in the
chamber a through the pipe J, into the tank D. The other end of the cylinder
being at the same time filled from the tank E, the water thus required being the
ainount consumed in regular duty.
'
In this manner it will be seen that the water supplied through the pipe S, and
provided by pumps or gravity, has to be delivered against the minor head equal to
the height of the tank E, the weight of the water used on the descending stroke
is only equal to the service loads raised, less friction and the unbalanced weight of
the cage.
The functions of the two valves Q and L can be combined in one valve or
apparatus of any of the well-known forms for three-way hydraulic valves. I have
employed in this case two common stop valves to render explanation more easy, and
the manner of operating more clear.
The stop valve R, in the pipe J, is to regulate the flow from the tank D into the
chamber a, consequently the speed at which the piston B and the cage C will move
on the upward or downward stroke of the latter.
As the cage C descends there is added to its weight so much of the rope or
chain Fas passes over the pulleys I, and is suspended above the cage. This, in a

page_text: long range or a high building, varies considerably what is called the dead weight of
the cage. This accretion of weight by reason of the descending rope, I compensate
by making the tanks E and D of such diameter that the head of water or pressure
therein will rise or fall in proportion as the weight of the descending rope increases
on the down stroke of the cage C, or the same object can be attained by closing
these tanks and confining the air therein, so the variations of pressure required to
balance the variable weight of the rope or chain will be accomplished independent
of the head of water or in conjunction therewith.
In this manner, as the cage C rises and as the weight of the suspended rope
diminishes, the water or air pressure, or both, will fall in the tank D, as is required
to counterweight the suspended chain or rope.
The diameter of the tank D and the height the water rises therein can be adapted
to the weight of the chain or rope, whatever the latter may be.
Referring next to Fig. 5:
This represents another modification of my improvements in compensating
hydraulic elevators. A, is an operating hydraulic cylinder; B, a supply tank
containing water under pressure; C, a pump for forcing water into the tank B ;
and D, a discharge tank, into which spent water is led from the cylinder A, and
from which the pump C draws its supply; E and F, are multiplying sheaves,
around which the lifting rope G, is passed with a sufficient number of wraps to
multiply the movement of the cage in proportion to its required range compared
with that of the hydraulic piston H.
The sheave or wheel E, is attached to the cylinder A, and is fixed, the one F is
attached to the crosshead I, and to the piston rod J, and moves with the piston H,
being supported on the rollers L, moving on the guides M. Water is forced by the
pump C, through the pipe N, into the receiver or supply tank B, which is partially
filled with air so as to exert an elastic pressure on the water. O is a supply pipe
connecting the tank B with the chamber P, of the hydraulic cylinder A, and
permitting free passage of the water between the two.
Qis another supply pipe connecting the tank B with the chamber R in the
hydraulic cylinder A, a valve S being provided to control the flow of water in this
pipe Q to the chamber R, also to permit the spent water to flow from the chamber R,
through the discharge pipe T, to the waste tank D.
The valve S is operated by a wheel U, and a chain or rope W, extending to the
cage which is suspended by the rope extending onward from G.
This valve in one position permits free flow from the tank B to the chamber R
of the hydraulic cylinder A. In the other position it shuts off the flow from the
tank B and permits the water in the chamber R to escape by the pipe T into the
tank D, to be again forced into the tank B by the pump C.
Referring now to the operation of the machinery, and supposing the cage is to
be raised; both ends of the hydraulic cylinder at P and R being filled with water,
the valve S is raised, permitting the water in the chamber Ⓡ to escape by the
pipe T into the tank D.
This relieves the piston H of pressure on its outer or piston rod side, and subjects
it to fuel pressure on its whole area on the other side next the chamber P, forcing
out the piston rod J, sheave wheel F, and hauling down the rope G at X, raising
the cage to which the rope is attached.
The cage not being counterbalanced, this operation raises the dead weight of
the cage and its attachments as well as any load thereon at a seeming loss of power
for raising the dead weight, but this power is given back in the following manner,
supposing the cage is to descend. The valve S is shifted so as to cut off com-
munication to the discharge pipe T, and open communication from the tank B to
the chamber R and to the outer side of the piston H. The latter will then be in
equilibrium, both sides, so far as exposed, sustaining the same pressure from the
tank B, but the outer side of the piston next the chamber R, is reduced in arca
equal to the cross section of the piston rod J, but this area is so made that the
weight of the cage will represent a pressure thereon equal to that of the water

page_text: from chamber B and enough additional to compensate for friction or other
resistance as the cage descends.
As the cage is lowered and the piston makes its inward stroke, the water in the
chamber P is forced back into the supply tank B. In the mean time the water
contained in the chamber R will be as much less than that expelled from the
chamber P, as the volume of the piston rod in the chamber R represents.
In this manner the real volume of water returned to, and retained in the
receiver B, will be equal to the cubic contents of the piston rod J, that enters the
chamber R, and this water so returned, constitutes so much stored energy derived
from the gravity of the descending car, to be again applied on the next upward or
lifting movement of the piston and cage.
Referring now to the receiver B and the pump C, this method of producing
water pressure is employed to illustrate the present invention, but it is obvious that.
the result attained, as well as the arrangement of the hydraulic cylinder, and its.
attendant parts, and the manner of operating, will be the same, whether water
pressure was derived from gravity, direct steam pressure, or in any other manner,.
the most common being pressure derived from public service in cities by connection.
to water mains.
Referring next to Fig. 6:
In this modification of my invention I have shown the method applied to the.
motive mechanism of a common elevator consisting of a main actuating cylinder A,
in a horizontal position; hydraulic piston B, piston rod C, movable sheave D,.
and stationary sheave E. Around these latter passes a rope or chain F, with
wraps on the sheaves in proportion to the relative movement of the piston B and
that of the load or resistance, which, in the case of an elevator, is suspended by the:
end of the rope G passing up to and over the sheaves at the top of the building i
the usual manner.
in.
The movable sheave D is mounted in the crosshead H, supported on the rollers I,.
that move on the ways J, producing a true rectilinear movement of the piston,
rod C. K is the main supply tank, containing water under pressure derived from
the force pump L. This vessel or tank K is partially filled with air or other
elastic fluid, or subject to pressure by an accumulator or a head of water.
Water is admitted through the pipe M from the bottom of the vessel K to the.
controlling valve O, and from there to the cylinder A. through the inlet P,.
and acts upon the piston B with a force equal to the area of the piston and the
pressure employed. This causes an outward movement of the piston B, piston
rod C, and the sheave D, acting on the rope F in the usual manner to raise a cage.
or other weight to which the end of the rope G is attached.
The valve O is preferably of the piston type, having the function of opening
communication between the vessel K and the cylinder A on one stroke, and on the
other stroke opening communication between the cylinder A and the vessel Q.
through the pipe R, and when in a central or neutral position, closing all the
passages as a stop cock.
This valve O is operated by a wheel, pinion and rack, in the usual manner, as
shown in the drawing, by levers or any of the well-known devices employed for
that purpose, and is controlled by a rope or chain S, that can be led off in any
direction, as required. The functions of this valve O being common to all of its.
class no description of it is required.
When a weight is raised, and the outer stroke of the piston B is completed, and
its motion to be reversed, the valve O is changed to the position that opens.
communication from the cylinder A to the vessel Q, and as the piston B makes its
back or inward stroke by the overhauling of the rope F, the water contained in
the cylinder A is, by this movement, forced into the vessel Q against such pressure
therein as the returning force will permit. This vessel Q is subjected to an.
elastic pressure by being partially filled with air, provided with a head of water, or
an accumulator piston that will offer a resistance to the incoming water equal to a.
predetermined load or resistance on the rope G.

page_text: The water thus forced into the vessel Q is again returned to the vessel K by the
pump L, which performs a duty as the difference in the pressure in the tanks K
and Q, and not against the whole pressure required in the tank K, thus utilizing
the reactive or return force of the cage, and a predetermined load thereon,
whatever it may be, acting on piston B.
It will thus be seen that the water in its operating course passes_successively
through the vessel K, the cylinder A, the vessel Q and the pump L, the latter
supplying the motive power to operate the hydraulic apparatus and for lifting the
actual load, including a cage or constant weight, but no more, because the reactive
force of a cage or any predetermined load on the piston B, is represented by an
equivalent pressure in the vessel Q, thus relieving the duty of the pump L to the
same extent.
Referring next to Fig. 7:
This part of my invention is intended to give warning, in case water in the
receiver or accumulator of a hydraulic elevator operated by steam or air, should
fall so low as to endanger the passage of the elastic impelling fluid, air or water,
into the hydraulic cylinder.
A is a hydraulic cylinder, operating a cage or platform by means of a rope B
passing around the multiplying sheaves or wheels C, C, in the usual manner.
D is a receiver from which water flows backward and forward to the hydraulic
cylinder A. E is the main pipe connecting the two together.
F is the main valve, controlling the flow of water between the cylinder A and
the receiver D, and G an automatic cut-off valve that also stops the flow of water
from and to the cylinder A at the two extremes of the stroke of the piston H.
I is a steam pipe leading from a boiler, or other supply of steam or air under
pressure, to the top of the receiver D, the flow thereto and therefrom being
controlled by a valve J, which in one position admits the air or steam to the
receiver D, and also in another position opens communication to the exhaust
pipe M, permitting the air or steam to escape to the open air, or to a condenser,
or in some cases to the main cylinder A, to replace water flowing from there back
to the receiver D.
The main water valve F and the steam or air valve J are moved simultaneously
by means of cords or chains e, all operated from the same mechanism, commonly
a wheel indicated by dotted lines at K, and turned by suitable appliances operated
from the elevator cage, in the usual manner.
The automatic cut-off valve G is operated by the rod N, that has a twisting
motion imparted to it by the movable crosshead O, acting on the spiral tappets L, L,
so the water is cut off and motion arrested independent of the main valve F when
the crosshead O reaches the extreme of either its inward or outward stroke.
P is a float moving in the vessel Q having a stein R attached to the top and
sliding through a packed gland S.
The vessel Qis connected at its top and bottom with the receiver D by means
of the pipes T, T.
Attached to the gland S is a wire U, leading to one pole of an electric battery,
and a second wire V attached to an insulated collar W on the stem R.
When the water falls in the receiver D to the line a, it flows at the same level
in the vessel Q, and the float P and stem R descending until the collar W comes
in contact with the gland S, closing the electric circuit, and by means of the
conducting wires and the usual electrical apparatus, ringing a gong or bell to give
warning of the water being too low, and danger of steam, or gas, from the
receiver D passing into the cylinder A. and permitting, or causing, false movement
of the piston H, and of an elevator cage attached thereto.
In ordinary working, when steam is employed as the propelling power, the
waste of water that occurs in case of leakage, or from any cause, is, in part, made
up by condensation in the receiver D, but when this receiver becomes hot, or when
compressed air is employed as the impelling agent, there is a constant waste of
the circulated water by leakage past the main piston, around glands and otherwise,

page_text: so that without means of indication the water may sink so low in the receiver D
as to permit the escape of steam or air to the hydraulic cylinder, and by elastic
action endanger the hoisting machinery.
This danger is guarded against by the devices I have herein shown, by indicating,
at each stroke of the hydraulic piston, how much water remains in the receiver or
accumulator D, and also when the water has receded to a point of danger; giving
audible notice of that fact by means as herein described.
Referring next to the valves to control the flow of water and applicable to that
class of compensating hydraulic elevators wherein the water circulated through
the valve acts on both sides of the hydraulic piston, reference is now made to
Figures 8, 9 and 10. These represent the method of constructing and applying
my improvements in controlling valves to hydraulic elevator apparatus.
Fig. 8 shows a common hydraulic cylinder A with a piston rod B¹, rope
sheaves C¹, C³, a main valve D, and an automatic stop valve E, the latter operated
by the rod F and spiral tappets G, G', these being turned right and left by a
sliding tappet H attached to the piston rod B¹, or its crosshead B².
The tappet H enters the spiral slots in the tappets G₁, G³, turning the rod F
right and left, and by means of the crank I, link J and crank K, opening and
closing the valve E positively and automatically at the extremes of the stroke of
the piston, and also at the extreme of the range of the elevator cage up and down,
independent of the main valve D.
In order to understand the action and functions of this automatic valve E,
reference is made to Figure 10, which shows a central transverse section of the
same. There is a central oscillating axis 0, on which are two opposite arms M, M,
and to these are attached the pivoted valves N, N, adapted to cover the ports or
passages P, P.
It will be seen that when the axis O is turned to close either of the ports P the
other port will be open, the flow being closed in one direction only. If the flow
is reversed, the closing valve swings back offering no obstruction to the fluid
flowing through both valves.
In this manner the flow of the fluid and the movement of the piston and
elevator is stopped in one direction, but when reversed by action of the main
controlling valve D the stop valve E offers no obstruction to the reversed flow of
the fluid until the other extreme of the stroke is reached, when by action of the
mechanism before described the valve again closes.
'
Referring next to the main controlling valve D, represented in the enlarged
section in Fig. 9, the main shell or casing is composed of five sections Q¹, Q³, Q³‚°Q*
and Q.
These sections are all held together by means of the rods or bolts R, R.
extending the whole length as shown. The section Q' is provided with a waste
or discharge nozzle To, the sections Q3, Q, with inlet or circulating nozzles T', T',
and the section Qwith a supply nozzle T, as shown in Figures 8 and 9, the
nozzle T' being in the case of Fig. 9 turned 90 degrees from the position shown
in Fig. 8, to enable easier description.
The sections Q¹, Q³, Q³, and`Q, fit together at the joints e, e, e, with short
telescoping nipples that bear upon and expand elastic packing rings a, a, a. These
packing rings perform the double function of sealing the joints e, e, e, and at the
same time embracing and forming a close water packing around the shells or
barrels U³, and U*.
The first or main internal shell or chamber U³ is secured by a rim or flange b
held under the cap W. V1, V2, and V, are leather packed pistons of the usual
kind, and V is an unpacked disc or flange permitting some water to pass, as will
be explained further on.
The four pistons V, V, V, V, are all rigidly mounted on, or formed integrally
with tube X. This tube X forming an axis of the pistons named is open at each
end as shown, and has perforations e in the chamber Y¹ admitting supply water
B

page_text: between the two small pistons d' and d³, also perforations o, admitting supply water
to the chamber Y, between the small pistons d³ and d³, and to the chamber Y*, as
will be presently explained.
-The rod Z and pistons d', d², and dª are moved by the sliding rack 9, the toothed
segment and wheel i by means of a rope or chain passing around the latter in
the usual manner.
Referring next to the operation of the valve, the chamber Y¹ is constantly filled
and under pressure of the supply water from the inlet nozzle T, and the piston V
not being a close one the inner or opposite faces of the pistons V and Vare
subjected to the same pressure, exerting a force each way in proportion to their:
areas, but as the piston V' is much larger than the one V, there is a force to the
right or outward that moves the tube X and all the connected pistons in that
direction. This movement is performed by moving the rod Z outward until the
small piston d³ passes out of the tube X, so the water in the chainber Y' can pass
through the small ports o, o, into the tube X, and out at its end into the
chamber Y, from where it escapes by a wasteway k. This relieves the piston V*
from pressure on the chamber Y, and the tube X with its attached pistons move
to the right.
It will be seen that this movement is progressive, the main pistons and the
tube X following the rod Z and small piston d³, which if overtaken closes the end
of the tube X and locks the water contained in the chamber Y', so the movement
of the main pistons and their supporting tube follows in exact relation the
movements of the rod Z, and the small pistons d', d³, and d³.
The reverse movement of the tube X and its attached pistons is performed by
moving the rod Z and pistons d', d, and d³ to the left, or inward, until the small.
piston passes beyond the ports c, c, and the piston closes the end of the
tube X. This permits the supply water to rush into the tube X through the
ports c, and out at the ports o, o, filling the chamber Y' and putting the large
piston Vinto equilibrium, so the piston V' will move to the left and to the
position shown in the drawing.
In this position the water will pass from the supply chamber Y¹, past the
retarding disc or piston V through the nozzle T and down through the valve E
to inner end y of the main cylinder A, but no movement of the piston or piston
rod B' can take place because the other or outer end q of the main cylinder A is
filled with water, forming there an abutment.
To finish the outward stroke of the piston B' and raise the cage of the elevator,
the rod Z is farther advanced, the valve pistons following until the piston V'
passes over the ports m in the shell U', then the entrapped water in the outer
eud q of the main cylinder A rushes up the pipe / through the nozzle T¹,
from the chamber Yinto the chamber Y, and escapes at the nozzle To through
the waste pipe n. This constitutes the working stroke of the main piston B' and
raises the elevator cage.
passes
When the downward stroke is to be made the rod Z is moved to the right or
outward, the tube X and pistons thereon following, in the manner before explained,
until the piston V' is so far advanced in the chamber Y' that the water can pass
from the nozzle T' to the nozzle T', or circulate from the inner end y of the main
cylinder A to the outer end 4, putting the main piston into equilibrium, and the
cage will descend irrespective of pressure in the ends of the main cylinder A.
But the cubic capacity of the end 9 of the main cylinder A being reduced by so
much as the contents of the immersed portion of the main piston rod B', an equal
volume of water cannot enter the chamber Y', but is forced back into the
chamber Y' and out at the nozzle T against the supply pressure.
The retarding or check piston V is to prevent back flow of the water from the
chamber Ys to the chamber Y' in case too heavy a load is placed on the elevator
cage, greater than the supply pressure will sustain, or in case the supply pressure
should from any cause be diminished or fail. When in the position shown, it

page_text: guards against a rush of water past this piston or disc, and consequently against
rapid or dangerous descent of a cage or load.
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 hydraulic hoisting and lowering machinery, a hydraulic cylinder placed
vertically or horizontally, in combination with a receiver connected therewith, of
such relative form, and at such height above the hydraulic cylinder, that the
gravity of the fluid circulating between the hydraulic cylinder and the receiver
will compensate or counterbalance the weight of the cage and connected parts,
except so much of this weight as is required to cause the cage to descend when
unloaded, substantially in the manner described herein and illustrated in Fig. 1 of
the drawings.
2. In hydraulic hoisting and lowering machinery, a hydraulic cylinder and a
piston therein, both sides of which are acted upon by the fluid under pressure;
with a valve or valves to control the flow of the water, and permit it to pass from
one side of the piston to the other, the piston so arranged that the difference of
pressure on its two sides, or on the outward and inward strokes, will equal and
substitute a required counterweight for the cage and its connected parts, in the
manner substantially as described herein and illustrated in Figures 2 and 3 of the
drawings.
3. In hydraulic hoisting and lowering machinery, a hydraulic cylinder with
distributing valves to permit the water pressure to act on one side, or on both
sides, of the piston head; a piston rod, the diameter or area of which multiplied
by the fluid pressure will equal the gravity of the cage and its connected parts,
and thus dispense with suspended or other counterweights for the cage, in the
manner substantially as specified herein and illustrated in Figures 2 and 3 of the
drawings.
4. In bydraulic hoisting and lowering machinery, a hydraulic cylinder and a
piston moving therein, one side of the piston exposed to the constant pressure of
circulated water, and the other side to a lesser pressure from the supply source,
the latter acting in conjunction with the weight of the cage to produce the desired
operating pressure each way; valves to control the flow of water from the supply
source and to a waste pipe; independent pipes connecting to the two ends of the
cylinder, and the two sides of the piston; a body of circulating water connected to
one end of the cylinder, and a supply at lesser pressure connected to the other end
of the cylinder, so arranged that the weight of the cage, or the dead load, will
make up the difference of pressure on the two sides of the piston, less what is
required to overcome friction of the machinery, substantially as herein described
and illustrated in Fig. 4 of the drawings.
5. In bydraulic hoisting and lowering machinery, a cylinder and a piston moring
therein; independent pipes connecting to the two ends of said cylinder, and to the
two sides of the piston, as herein described; one pipe connecting to a tank
containing circulated water, the tank so formed that the head and pressure of water
therein will rise and fall, and the pressure vary so as to counterweight varying
weight of the suspended portion of the rope or chain on which the cage is
suspended, in the manner substantially as herein described and illustrated in
Fig. 4 of the drawings.
6. In hydraulic hoisting and lowering machinery, a hydraulic cylinder and a
piston moving therein; pipes and connections for water, so arranged that one end
of the cylinder and one side of the piston will be constantly in connection with
the supply of water under pressure, the flow to and from this end of the cylinder
being free and unimpeded in either direction; the other end of the hydraulic
cylinder connected to the same source of water pressure and provided with valves
to control the flow outward and inward from the hydraulic cylinder; the hydraulic ·

page_text: cylinder at each end, and the hydraulic piston at each side, connected to the water
supply by separate and independent pipes, in the manner substantially as herein
described and illustrated in Fig. 5 of the drawings.
7. In hydraulic hoisting and lowering machinery, a hydraulic cylinder, one end
of which is connected to and communicating with two vessels or tanks, each under
pressure but of different degree, so the hydraulic piston may be subjected on the
same side to the pressure in either vessel or tank; suitable pipes and valves to
open connection between either vessel or tank and the hydraulic piston, as the
latter may be raising or lowering a load, substantially in the manner herein specified
and illustrated in Fig. 6 of the drawings.
8. In hydraulic machinery for hoisting and lowering, a hydraulic cylinder and
piston connected by suitable pipes to two vessels or receivers; a valve or valves
controlling communication between the bydraulic cylinder and the two vessels or
receivers, in one of which is maintained pressure capable of performing the
maximum duty required by the hydraulic piston, the other sustaining a variable
pressure due to a descending load or weight acting on the hydraulic piston on its
return stroke, thereby discharging the water in the hydraulic cylinder into the
low-pressure vessel or receiver; a pump constituting the motive power, forcing
water from one tank or receiver to the other, operating against the difference of
pressure in the two, in the manner substantially as herein described and illustrated
in Fig. 6 of the drawings.
9. In hydraulic machinery for hoisting and lowering, a hydraulic cylinder and a
single-acting piston therein; pipes connecting and forming communication from
the hydraulic piston to two vessels or receivers in which the difference of pressure
on the water corresponds to the weight of a service load raised, so that any
descending dead weight will be utilized in the vessel of least pressure, and be
deducted from the duty of a pump supplying the motive power, in the manner
substantially as herein specified and illustrated in Fig. 6 of the drawings.
10. In hydraulic machinery for hoisting and lowering, the primary force being
derived from an elastic gas, steam or air; a main hydraulic cylinder connected to
a receiver, the latter provided with an indicating float and announcing mechanism
to guard against the water in the receiver falling so low as to permit the steam or
air to pass to the hydraulic cylinder, in the manner substantially as herein
described and illustrated in Fig. 7 of the drawings.
11. In hydraulic machinery for hoisting and lowering, a main hydraulic cylinder
connected to a receiver containing steam or air under pressure; an indicating or
announcing float, or both, attached to the receiver, so as to show the height of
the water therein; electric wires connecting to the float, so the circuit will be
closed at some predetermined point, and by a gong or other apparatus give notice
of the fall of water, in the manner substantially as herein described and illustrated
in Fig. 7 of the drawings.
12. In hydraulic machinery for hoisting and lowering, a main hydraulic cylinder
connected to a water supply under pressure; a three-way piston valve to control
the flow of water to and from the hydraulic cylinder, and from one end to the
other thereof, the valve actuated by pistons; a hollow supporting stem and primary
controlling valves therein, in the manner substantially and for the purposes specified
and described.
13. In hydraulic machinery for hoisting and lowering, a main cylinder and a
controlling valve connected thereto, the latter having pistons and ducts whereby
the water is admitted, circulated and discharged by the rectilinear movement each
way of a primary central controlling valve placed in the tube formed integrally
with and supporting the actuating and water-controlling pistons of the main valve,
in the manner substantially as shown and described.
14. In bydraulic machinery for hoisting and lowering, a main controlling valve
having inlets and outlets as shown; actuating pistons to move the valve, and a
retarding or regulating piston to determine the, maximum flow and speed of the

page_text: main hydraulic piston and connected machinery when the load or resistance
exceeds the primary moving force, in the manner substantially and for the purposes.
specified.
3
ALLISON BROS.,
Agents for the Applicant.