US3065738A

US3065738A - Hydraulic elevator jack units

Info

Publication number: US3065738A
Application number: US93451A
Authority: US
Inventors: Robert F Loughridge
Original assignee: Esco Elevators Inc
Current assignee: Esco Elevators Inc
Priority date: 1961-03-06
Filing date: 1961-03-06
Publication date: 1962-11-27
Anticipated expiration: 1979-11-27

Description

Nov. 27, 1962 R. F. LOUGHRIDGE HYDRAULIC ELEVATOR JACK UNITS Filed March 6, 1961 IHI W A .W l

United States Patent Oflfice 3,655,738 ?atented Nov. 27,, 1962 3,665,738 HYDRAULIC ELEVATOR JACK UNITS Robert F. Loughridge, Fort Worth, Tex., assignor to Eseo Elevators, Inca, Fort Worth, Tex. Filed Mar. 6, 1961, ger. No. 93,451 Claims. ((11. 121-46) My invention relates to hydraulic elevators, and more particularly to apparatus and arrangements involving hydraulic elevator jack units.

In hydraulic elevator installations, it is necessary that the elevator lift plunger extend below ground level. The plunger operates within a cylinder or housing which contains the hydraulic fluid which is pumped under pressure to power the elevator. Thus, the major portion of the jack unit length is beneath ground level with the cylinder or housing exterior exposed to the earth. In spite of best efforts, such as wrapping, coating, and the like, the jack unit cylinder or housing is subject to corrosion and erosion due to both chemical and electrolysis action. When such corrosion or erosion or both progress sufliciently, the cylinder or housing will become ruptured, allowing loss of hydraulic fluid and consequent elevator malfunction. In some cases, the rupture may be sudden and extensive, causing the elevator to drop, with possibly disastrous results.

The general object of the present invention is to provide improved elevator jack units. A more specific object is to provide improved jack unit housing arrangements which will give advance warning of housing ruptures, and which will prevent the possibility of accident due to sudden and extensive housing rupture. A further object is to provide improved jack unit arrangements which will allow the elevator to be placed back into normal operation immediately, following the occurrence of a housing rupture.

The present invention contemplates that the portion of the jack unit cylinder or housing that is beneath ground level and exposed to corrosion and erosion action shall have a double wall, with a hydraulic fluid flow passage of selected size communicating between the inner wall interior and the space between the two housing walls. Thus, the housing inner wall will not be exposed, and cannot corrode or erode. Hydraulic fluid will fill the space between the inner and outer Walls so that when there is an outer wall rupture, the hydraul c fluid loss will be at a controlled rate determined by the selected size of the fluid flow passage above mentioned. This controlled fluid flow rate may be such as to cause a noticeable downward drop of the elevator so that the existence of a housing exterior wall rupture will be apparent, but this downward drift cannot exceed the rate determined by the fluid flow passage, and thus the elevator would never fall even if a sudden and extensive rupture occurred. In a preferred form of the invention, the controlled fluid flow passage would be located above ground and would extend from the exterior of the inner wall to the exterior of the outer wall and thus be accessible so that, when a rupture occurs, the elevator can be immediately placed back in normal operation by merely plugging the passage. Also, if desired, a valve could be interposed in the passage so that the fluid flow rate could be adjusted to any rate desired, and also could be shut off entirely upon occurrence of a rupture. Such a valve, though convenient, would be subject to the hazard that it might be inadvertently left in the closed position so that the occurrence of a rupture would not be apparent.

The 'way in which the present invention achieves its aims will be further understood from the following description of a preferred embodiment (given for purposes of illustration and without unnecessarily limiting the scope of the invention), and taken in accordance with the appended drawings, forming a part of this application, in which:

FIGURE 1 is a schematic view, partially in section, showing a jack unit in accordance with the present invention, in a typical installation;

FIGURE 2 is a schematic longitudinal section view of a jack unit embodying the principals of my invention; and

FIGURE 3 is a schematic view, partly in section, illustrating installation of a jack unit in accordance with the invention to replace a jack unit that has failed due to erosion and corrosion.

In FIGURE 1 there is shown a jack unit 11 extending down into a well in the ground 13. The jack unit includes an inner housing or cylinder 15 which is nested within an outer housing or cylinder 17. The outer housing has a plurality of load support pads 19 disposed around its outer periphery and integrally fixed to the outer housing a short distance below the upper end thereof. These pads rest on the floor 21 of the elevator pit 23 and serve to support the elevator and its load upon the pit floor. The elevator car 25 travels within the guide way 27 and is fixed by suitable bolts 29 to a flange 31 which is integral with the upper end of the jack unit plunger 33. The jack unit outer housing 17 has an integral ring flange 35 at its upper end. The jack unit inner housing is provided an integral ring flange 37 a short distance below its upper end, and this ring flange 37 rests upon the ring flange 35, so that the inner housing 15 is actually supported by the outer housing 17. The

flanges

35 and 37 are clamped together by suitable bolts 39. A gasket (not shown) may be provided between the

flanges

35 and 37 to make a hydraulic fluid-tight seal. The jack unit inner housing has an integral ring flange 41 at its upper end which is mated in fluid-tight relation with a ring flange 43 which in turn is a part of a plunger guide and packing assembly 45. The plunger guide and packing assembly 45 is of a conventional type and is clamped to the jack unit inner housing 15 by means of bolts 47.

The inner housing 15 together with the plunger guide and packing assembly 45 provides a fluid-tight container. Hydraulic fluid is pumped into the container via inlet 49 to exert pressure on the plunger lower end 51 to raise the elevator and its load. When the elevator is descending, fluid is allowed to escape at a controlled rate via inlet 49 and suitable valves and conduits to a hydraulic fluid reservoir (not shown).

The diameter of the jack unit inner housing exterior is less than that of the jack unit outer housing interior. Also, the extremity of the inner housing bottom exterior is preferably above the bottom of the outer housing interior. Thus, there is found an annular space 51 and a cylindrical space 53 between the exterior of the inner housing 15 below the ring flange 37 and the interior of the outer housing 17. This

space

51 and 53 is hydraulic fluid-tight, and is interposed between the inner and

outer housings

15 and 17 over the entire region of exposure of the outer housing 17 to corrosion and erosion due to chemical and electrolysis action. The inner housing 15 has a threaded opening 55 located immediately above ring flange 37; and the outer housing 17 has a similar threaded opening 57 located immediately below ring flange 35. A conduit 59, made up of nipples 61, elbows 63, and a union 65 communicates from the inner housing interior via opening 55 to the

space

51 and 53 be tween the inner and outer housing, via opening 57.

It should be apparent from the foregoing that the elevator jack units made in accordance with the principals of my invention are effective to give notice of housing ruptures, to prevent elevator drop due to sudden and extensive housing ruptures, and to allow immediate return of elevator to normal service following occurrence of a rupture.

The jack units of my invention are applicable as replacements in existing installations as 'well as for new ones. The application to an existing installation is illustrated by FIGURE 3, wherein there is shown the housing 59 of an old jack unit housing which has eroded and ruptured at 61. The old housing has been cut off just above the floor of the pit 21 and a new jack unit has been inserted in the old housing. The outer housing 17 of the new jack unit has been welded at 63 to the upper end of the old housing 59 to prevent water from rising up into the pit 21.

While I have shown my invention in only one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

I claim:

1. A jack unit for a hydraulic elevator comprising an outer cylindrical housing adapted for insertion in an earth well with an upper portion protruding above ground and terminating in an annular flange, an inner cylindrical housing having an integral exterior ring flange beneath its upper end and mating with said annular flange to support said inner housing on said outer housing in nested spaced relation, means joining said flanges in hydraulic fluid-tight relation, and a hydraulic fluid conduit communicating from said inner housing interior above said flanges to said outer housing interior below said flanges and exteriorly of both said housings.

2. A jack unit for a hydraulic elevator comprising an outer housing adapted for contact with earth below ground, an inner housing supported on said outer housing in nested relation thereto, said inner housing adapted for receiving an elevator load carrying plunger for reciprocable motion and in hydraulic fluid-tight relation, with said housings defining a hydraulic fluid-tight housing therebetween, means providing ingress and egress of hydraulic fluid to said inner housing, and means allowing controlled leakage of hydraulic fluid from said inner housing to said outer housing.

3. A jack unit for a hydraulic elevator comprising an outer housing adapted for contact with earth below ground, an inner housing supported on said outer housing in nested relation thereto, said inner housing adapted for receiving an elevator load carrying plunger for reciprocable motion and in hydraulic fluid-tight relation, with said housings defining a hydraulic fluid-tight housing therebetween, means providing ingress and egress of hydraulic fluid to said inner housing, means accessible and aboveground for allowing controlled leakage of hydraulic fluid from said inner housing to said outer housing.

4. A jack unit for a hydraulic elevator comprising an outer housing for insertion into an earth well with an upper portion protruding aboveground, an inner housing nested within said outer housing and spaced therefrom so as to define a hydraulic fluid-tight cavity therebetween, with said inner housing protruding above the upper portion of said outer housing, and a fluid conduit communicating between said inner housing and said outer housing exteriorly of both said housings.

5. A jack unit for a hydraulic elevator, said jack unit comprising a plunger, an inner housing adapted for receiving said plunger for reciprocable motion and in hydraulic fluid-tight relation, an outer housing adapted for receiving said inner housing in nesting spaced relation, a hydraulic fluid supply opening in said inner housing, and a hydraulic fluid passage communicating between said References Cited in the file of this patent UNITED STATES PATENTS 654,876 Dean July 31, 1900 1,720,434 Pedersen July 9, 1929 FOREIGN PATENTS 38,196 Germany June 11, 1886