US243649A - Hydraulic elevator - Google Patents

Description

(No Model.)

S. E. STORES! Hydraulic Elevator. No. 243,649. Patented June 28,1881.

g Y UQ/.

ZQQ; v)Lf N. PETERS, PhawLnhognghnr. wumngnn. nl:v

UNITED STATES PATENT OFFICE- SAMUEL E. STOKES, OF PHILADELPHIA, PENNSYLVANIA.

' HYDRAULIC ELEV'ATOR.

SPECIFICATION forming part of Letters Patent No. 248,649, dated June 28, 1881. Application tiled April 22, 1881. (No model.)

To all 'whom it may concern:

Be it known that I, SAMUEL E. SToKEs, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Hydraulic Elevators, of which the following is a specification.

My invention relates to that class of hydraulic elevators in which a vertical cylinder having a piston connected to the cage or car is combined with appliances by which water under pressure can be admitted to the cylinder above the piston for hoisting, and to the cylinder below the piston for lowering the car; and the object of my invention is to return the water which has been used for lowering the piston and raising the carto the source of 'supply during the raising of the piston and lowering of the car, so that there shall be only one discharge through the waste-pipe of one cylinderful of water during one complete trip up and down of the ear,instead of two discharges.

In the accompanying drawings, Figure 1 is a side view, drawn to a reduced scale, of my improved hydraulic elevator; Fig. 2, part of.

Fig. 1, drawn to an enlarged scale; and Figs.

3, 4, and 5, sections of the ch ange-valve in different positions.

In the vertical cylinder Gis a piston, H, the

rod or rods I of which are connected to the cark W through the medium of differential drums, as shown, or through the usual block-and-fall mechanism, or any other available appliances, this part of the hoisting apparatus forming no part of my present invention.

Near the base of the cylinder is a chambered valve-chest, K, containing the change-valve M, and this chest communicates through a pipe, C, with the upper end of the cylinder above the piston, and through a pipe, D, with the cylinder below the piston. The chest also communicates, through the pipe A, with the tank N, through a pipe, B, with the same tank, and through a pipe, P, with the dischargechamber, the pipes A and B extending nearly to the bottom of the tank. This tank is closed, and a supply of water under pressure is forced into it to make up for the loss explained hereinafter; but there is always air in the tank above the water, and under sufficient pressure to actuate the`piston of the cylinder, in the manner described hereinafter.- The tank is adopted in cases where it is advisable to have the supply of water in the basement of a building, for an open tank, into which water is pumped, may be placed in the upper part of the building at such an altitude as to obtain thedesired pressure bythe head of wateronly; 0r the supply may be obtained directly from city mains where there is a sufficient head of water.

It may be remarked here that I do not desire either to claim or restrict myself to the valve and valve-chest illustrated in the drawings, as the results attained thereby may be accomplished by other systems of valves, ports, and passages, the plan shown being given as an example and as an aid to the explanation ofthe mainprincjples and operations of my invention.

We will suppose that the piston is approaching the limit of its downward movement, and that the car is approaching its highest'position, the valve being as shown in Fig. 3, so

that there will be aclear passage for water under pressure from the tank, through the pipe A, valve and pipe C, to the top of the cylinder, this being the condition of affairs from the time the'piston commenced to descend and the oar t0 ascend, the Water below the cylinder meanwhile escaping through the pipe D, the valve-chest and valve, and out through the discharge or waste pipe P. When the piston has to belraised and the-car lowered the valve is turned to the position Fig. Aet, when there is such a change of passages that water under pressure from the tank N will pass through the pipe B, valve-chest, and pipe D to the cylinder below the piston, the outlet to the escapepipe being closed. At the same time com munication is open between the cylinder at the top of the same and the tank through the pipe C,

valve-chest and valve, and pipe A. Under P cylinder on both sides ofthe piston is the same, there must be a less pressure on the top of the IOO piston, owing to the diminution of its area by the presence of the piston rod or rods, than there is on the under side of the said piston,

and this excess of pressure from below assists the carin its descent. When the car has to be arrested at any point between the limits of its upward and downward movement the valve must be entirely closed, as shown in Fig. 5, when the piston will be locked in the cylinder by and between two bodies of water which cannot escape.

It will be seen wit-hout further description that while two cylinders full of water are demanded by each round trip, up and down, of the ear, one cylinderful only is discharged through the waste-pipe, the other cylinderful being restored to the source of supply, and th at this return of water involves no expenditure of power, for the reason that during the ascent of the piston and descent of the cage the pressure on both sides of the piston is balanced.

Two sources of supply of waterone at a high pressure and the other at a lower pressure-have been described in connection with a vertical cylinder, piston, and cage in a hydraulic elevator, the water for the low-pressure supply bein gderived from the cylinder beneath the piston, while the high-pressure supply is depressing the piston and raising the cage. This plan differs, however, from my invention, in which there is but one source of supply to which the water expended in depressing the piston and raising the cage is returned to the said source oi' supply by the cage during its descent.

I claim as my invention- 'Ihe combination, in a hydraulic elevator in which water is returned to the single source of supply, of the following elements, namely: rst, a vertical vcylinder having a piston connected to a car or cage; second, means for obtaining a supply of Water under pressure for depressing the piston; third, a change valve or valves; fourth, pipes through which water from the cylinder above the piston may be directed by the valve or valves to the said single source of supply during the descent of the car or cage, all substantially as set forth.

In -testimony whereof I have signed my name to this specification in the presence of 5o two subscribing witnesses.

SAMUEL E. STOKES.

Vitnesses:

ARMEs F. MoCoRMrcK, HARRY SMITH.

Images