US1912103A

US1912103A - Air lift

Info

Publication number: US1912103A
Application number: US525395A
Authority: US
Inventors: Louis C Stukenborg
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-03-26
Filing date: 1931-03-26
Publication date: 1933-05-30
Anticipated expiration: 1950-05-30

Description

May 30, 1933 l.. c. STUKENBORG 1,912,103

AIR LIFT Filed March 26, 1931 Jaa/5 fare/vaya Patented May 30, 1933 UNITED STARS LoUrs c. srnnnnnone, or MEMPHIS, TENNESSEE AIR nir'r Application filed March 28, 1931. Serial No. 525,395.

This invention has reference to a lift or jack which is operated by compressed air through the agency of a liquid.

The objects of the invention are to provide 5 means whereby a lift plunger' is raised and supported through the medium of a liquid to which pressure is applied by compressed air; and

To provide means for automatically rel@ leasing the air pressure at a predetermined level whereby the amount of lift is limited and at the same time the actuating pressure is released on the raising liquid.

The means by. which the foregoing and other objects are accomplished and the manner of their accomplishment will readily be understood from the following specification on reference to the accompanying drawing, in which:

o Fig. 1 is a sectional elevation on the center line of a jack cylinder and of a compressedair tank associated therewith;

Fig. 2 is a plan view of the tank and the piping therefrom together with a diagrammatic view of an air compressor and an air reservoir associated with such air tank.

Referring now to the drawing, in which the various parts are indicated by numerals,

is a vertically disposed cylinder, prefer- 3 ably sunk below the ground level, in which is disposed a plunger 11 on the upper end of which is mounted a head 12 and such other -load carrying members as may be desired.

r 13 is a pressure tank. 14 is an air compressor u and 15 an air reservoir. 16 is a pipe leading from the air reservoir through a three-way valve, preferably a stop and waste cock 17,

into the top of the tank 13. 18 is an air release valve discharging from the top of the tank 13, which valve is closed by the upward,

or opened by the downward movement of a float 19 which within limits follows the level of the liquid 20 within the tank.

Leading from the bottom of the tank so that it is denitely below the liquid level is a pipe 21 which discharges into the cylinder 10. 22 is a by-pass pipe leading horizontally from this pipe back into the tank 13. 23 is a check valve in the line 21 between the tank and the by-pass line, this check valve permitting flow from the Vtank but preventing return flow thereto. 24 is a lever actuated gate or throttle valve, in the line 21 between the check valve Vand the cylinder and 25 is a ,valve in the by-pass line 22. u 1

In filling the tank the valves 24 and 25 are closed and such amount of liquid, preferably oil placed in the tank 13 as is necessary to raise the float 19 to a level which will just close the release valve 18. Such additional amount of oil is then added in the tank 13 as will be needed to raise the plunger 11 to desired height, this additional oil holding the release valve tightlyv closed. j

In using the device compressed.V air from the reservoir v15 is admitted to the tank 13 by opening the cock 17 establishing pressure on the oil therein. The throttle valve 24CV is opened and the oil caused to iiow to the cylin- ,der 10 by pressure of the air on the o il within the tank, thus raising the plunger.

' Air pressure is meanwhile maintained in the tank by the compressor. Rise of the plunger may be checked at any point by closing the throttle valve, but in case such closure is neglected, lowering of the oil and the float therein will open the release valve 18 and allow escape of the air pressure in the tank, and consequent checking of the plunger lift, but such air escape will not allow drop 's6 of the plunger since return iiow of oil is presented by the check valve.

At such time the compressed air cock should' be closed and air escape from the tank allowed there also, but air escape is posi'- tive 'as soon as` the speed of air release is greater than the inflow of compressed air, whether the air cock closure be made or not. As soon as the air cock is cut off escape of air from the tank relieves pressure on the oil ist and such pressure drops to that of the atmosphere. The oil which has passed the check valve 23 is retained in the cylinder and the plunger is necessarily held in raised position irrespective of such release of air pressure fe' in the tank. To lower the plunger the bypass valve 25 is opened and flow established through the by-pass line into the tank, this Y flow acting in such case against atmospheric pressure only and being therefore controlled solely by the amount of opening by the valve.

Having described my invention, what I claim is l. In a lifting mechanism, the combination, with a cylinder, a plunger therein, a closed tank for liquid, a pipe line connecting said tank with said cylinder, and ay pipe leading into said tank from a source of compressed air, of an air vent for said tank controlled by a float valve, the float having a level at and above which said vent is closed, and below which said vent remains open; and means whereby the extent of lifting movement of said plunger may be limited by limiting the volume of liquid initially placed in said tank above the level at which said vent valve is closed by said float.

2. In lifting mechanism, the combination, with a cylinder, a plunger therein, a closed tank for liquid, a pipe line connecting said tank with said cylinder, and a pipe leading into said tank from a source of compressed air, of an air vent for said tank controlled by a float valve, there being a predetermined level for the float at and above which said vent is closed, and below which said vent remains open; a valve for control ling the flow of compressed air to said tank; and means whereby the lifting movement of said plunger terminates when said oat descends below said predeterminedk level.

3. In lifting mechanism, the combination, i

with a cylinder, a plunger therein, a closed tank for liquid, a pipe line connecting said tank with said cylinder, and a pipe leading into said tank from a source of compressed air, of an air vent for said tank controlled by a float valve which is closed when the float is at or above a predetermined level, and remains open when the float is below said level; a by-pass from said pipe line to said tank; a check valve in said pipe line between said by-pass and said tank; and a three-way valve in said compressed-air line-whereby, during lowering movement of said plunger the oil in said cylinder is by-passed back into said tank, air meanwhile being vented from said tank through said vent and said three-way valve until the liquid in said tank raises the float suiiiciently to close the vent valve, after which air continues to be vented through said three-way valve.

In testimony whereof I hereunto affix my signature.

LOUIS C. STUKENBORG.