US2336808A - Hydraulic hoist - Google Patents

Description

Dec. 14, 1943.

R. W. SIMON HYDRAULIC HOIST Filed NOV. 2l, 1941 Patented Dec. 14, 1943 UNITED STATES PATENT OFFICE HYDRAULIC HOIST Ralph William Simon, Wyndmoor, Pa., asslgnor to Globe Hoist Company, Des Moines, Iowa, a corporation of Iowa Application November 21, 1941, serial No. 419,937 1 claim. (ci. en -51) Hoists of this class are ordinarily' operated by In the accompanying drawing: compressed air supplied from an electric motor- Figure 1 shows a side elevation of a complete driven compressor, and controlled by an electric hoist apparatus embodying my invention, parts switch device. being broken away to show structural details;

In plants engaged in the manufacture of high Figure 2 is an enlarged detail sectional viewI of explosives, such as T. N. T., such electrically opthe valve mechanism for controlling steam inlet erated and controlled hoists cannot-be usedwit and exhaust valves; and safety because of the probability of thegeneia Eigur'e 3 shows. an enlarged detail view of the tion of electric sparks. o 'v n device for controlling the water communi- In a certain plant of this character cat Qn betweenthe cylinder and tank. by the United States Government, there is 1. Theghoist cylinder is indicated by the reference man d for hydraulic hoists, and applicant has-` nu l I0, I'I is the hoist piston, I2 the fluid been advised that at said plant there, ;is always 'fm eA tank connected to the cylinder by the available an ample supply of high pressure stea" C :I3: generated at a safe distance fromvthe plantandl5, `vThe steam supply pipe I4 enters the top of the that there is also a limited supply ofllcompresr'sed tank I2 and has a branch I5 for exhausting steam air available at all times. l from the tank.

It was for the purpose of Vproviding a hoist In the pipe I3 is a diaphragm-operated valve especially adapted for these unusual conditions I6, of ordinary construction and characterized that the present invention was made. by being opened by a downward movement of the The object of my invention is to provide a hydiaphragm and spring closed, its valve being so draulic hoist of simple, durable and inexpensive positioned that pressure of fluid from the cylinconstruction and in which the power necessary der will tend to hold it closed. In the steam pipe to operate the hoist is obtained from high pres- I4 is a diaphragm-operated valve II, and in the sure steam, in contact with the liquid which steam exhaust pipe I5 is a similar valve I8.

raises the hoist, and more specically in this Leading to the top of the tank I2 is a water connection, and because under such conditions supply pipe I9, having a hand-operated valve steam will condense and greatly increase the vol- 20. Leading from the top of the tank I2 is a disume of the liquid, it is my object to provide for charge pipe 2| having a steam -relief valve 22. the automatic maintenance of the proper quan- 3U A water overflow pipe 23 leads from the tank tity ofliquid in the hoist tank. I2 at its desirable maximum water level, and it In hydraulic hoists which are air operated and is provided with an automatic relief valve such as use oil as the fluid, it is only necessary to apply a float valve 24 to permit excess water to disthe air pressure to raise the hoist, then shut oli? charge from the tank. s

the compressed air, whereupon the hoist is firmly 3'-, To provide for applyingand relieving air pressupported in any elevated position. With the sure to and from the several valves in proper seuse of steam as a pressure medium, and after the quence to operate the hoist, I have provided the steam supply is shut oi, it will rapidly condense following:

and, therefore, reduce the pressure upon the An air supply pipe 25 receives compressed air liquid, with the result that the hoist will move 4U from a suitable source of supply. It is provided downwardly. One of my objects is to provide a with a pressure regulating valve 26, of ordinary steam `operated hoist having means for autoconstruction.

matically supporting the hoist in ariV elevated I have provided a valve device for opening and position, regardless of the condensation of the closing the valves I1 and I8 in proper sequence, steam. comprising a valve chamber 26 into which the A further object is to provide a simple, durable air supply 25 enters. Communicating with this and inexpensive valve apparatus to be actuated valve chamber is a tubular valve member 21 exby compressed air for controlling the admission tended downwardly and connected to a pipe 28 to and exhaust of steam from the iiuid tank, leading to the exhaust valve I 8, this tube having and also for controlling the flow of liquid from two rows of openings 29 spaced one row above the tank to the cylinder for raising the hoist the other. Slidingly mounted on the tube 2'I is a piston, stopping all flow between the tank and hollow valve member 30 having tight iitting concylinder for holding the hoist piston stationary nection with the tube 21 and larger in diameter and permitting a return iiow for lowering the than the tube 2l, so that when in the position hoist piston. shown in Fig. 2, air will enter at the top of the tube 2'I and pass out into the valve member 3B, but cannot pass into the pipe 28 because of the partition 3l between the openings 29. When in this position the valve I'8 is closed.

On the opposite side of the chamber 26 is a similar tubular member 32 having similar rows of openings 33, a partition 34, and surrounding it is a sliding valve member 3-5. A pipe 36 leads from its lower end to the valve I1. When in the position shown in Fig. 2 air may enter pipe 36 and be conducted thereby to the valve II, to thereby open same and admit steam.

A rod 3'I is xed to each valve member 30 and 35, and is slidingly supported and projects above the valve chamber 26. Each has a spring 38 for holding it elevated.

Above the valve chamber 26 is a lever 39 fulcrumed between the rods 3'I so as to be engageable with the upper ends of the rods 31 as viewed in Fig. 1. By this means, when the lever 39 is in neutral position both of the valves I1 and I8 are closed, when moved upwardly one of said valves is open and the other closed, and when moved downwardly the opposite arrangement of open and closed position is elected.

For controlling the valve I6 in proper sequence with the valves I1 and I8 I have provided a valve 40 connected to the air supply pipe 25 at its upper end, and to the air pipe 4I at its lower end, and leading to the valve I6. The valve is provided with a port 42. A rotary valve member 43 has a port 44 extended through it, and an arm 45 on the rotary member provides means for operating it. The arm 45 is connected by the rod 46 with the lever 39, whereby the lever and arm are moved in unison. This valve permits the supply of air to the air pipe leading to the valve I6 when the arm 45 is either raised or lowered.

I have demonstrated in practice that with the use of steam as the power, and compressed air for valve control, the hoist is fully and completely controlled, and with safety against sparking.

When steam is being admitted to the tank the valve I6 is open and the Ahoist is raised by the water under steam pressure. When the hoist is stopped in an elevated position it is desirable that the steam supply be cut off to economize steam. When this is done the steam within the tank cools and condenses, thus reducing its pressure. In order to prevent this condition from permitting the hoist to lower, I have provided the valve I6 in the water pipe between the cylinder and tank, and which is automatically closed when the valve I1 is closed. When such condensation of the steam occurs, the pressure of the weight on the hoist greatly exceeds the pressure of the water within the tank. For this reason the valve I6`is designed to be forced against its seat by the pressure of the hoist and the hoist is firmly held elevated. When the hoist is being moved upwardly the valve I1 'and the valve I6 must both be open and the valve I8 closed, and when moving downwardly the valve I6 must be open, the valve I8 open and the Valve I'I closed. This operation of the valves in their proper sequence is effectively accomplished with my two valve devices operatively connected for joint action.

'I'he specific individual valve structures are of ordinary construction, and other specific valve structures having similar functions may be substituted. In the accompanying claim I desire it to be understood that it is not to be construed as limited to specific valve structures.

I claim as my invention:

An air-controlled hydraulic hoist, comprising a hoist cylinder, a piston therein, a liquid storage tank, a pipe connecting the storage tank and said cylinder, an air-controlled valve for controlling the flow of liquid through said pipe, a pipe for conducting fluid to the upper end of said storage tank, a second air controlled valve in said uid conducting pipe, an exhaust pipe for conducting fluid from the upper end of said storage tank, a third air-controlled valve in said exhaust pipe, a pipe forsupplying air under pressure, pipes for conducting air from said air supply pipe to each of said second and thid air controlled valves, a pilot valve in each of the pipes for conducting air to said second and third air-controlled valves, and capable of being moved to inlet, exhaust and neutral positions, a handactuated lever pivoted to swing from a predetermined neutral position to opposite angular positions, means operatively connecting said lever with the pilot valves for moving both of said valves to exhaust positions when the lever is at its neutral position, for moving one of said valves to exhaust position and the other to inlet position when the lever is at one of its angular positions, and for placing Said valves in reversed inlet and exhaust positions when the lever is at its opposite angular position, a pipe connecting said air supply pipe to the first air-controlled valve, a valve in the last said pipe having two inlet ports connected with said air supply pipe and an exhaust port, and means operatively connecting the last valve to said lever whereby said exhaust port will be opened with the lever in its neutral position and one or the other of said inlet ports will be opened when the lever is in either of its angular positions of movement.

RALPH WILLIAM SIMON.

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