US652983A - Air-hoist. - Google Patents

Description

- Patented July 3, I900.

4 Sheets-Sheet I.

jizyezzfix ewyeZJMm Y a. F. STEEDMAN. AIR HUIST (Application filed J'xinu 1.2, 1899.)

(m Model.

No. 652,983. Patented July 3, I900. G; F.-STEEDMAN.

Am HOIST. (Application filed June 12, 1899.)

4 Sheets-Sheet 2.

(No Model.)

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G F STEEDMAN Patented July 3, I900 A IB H0181: I (Applioationfiled Junoj12, 1899.) (No Model.) 4 SheetsShaet 3.

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' No. 652,983. Patented. luly 3,1900.

6. F. STEEDMAN.

AIR" HOI'ST. (Application filed June 15 2, 1899.)

(No Model.)

NITE STATES PATENT mes.

F-AlR-HOIST.

SPECIFICATION forming part of Letters Patent 0. 652,983, dated July 3, 1900. Application filed June 12,1899. Serial No. 720,191. (No model.)

will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in whichl Figure 1 is a front elevational view, partly broken away, of my improved air-hoist. Fig.

2 is a detail sectional view on line 2. 2,'Fig. 1.

Fig.3 is a vertical sectional View through the cylinder, showing the valve mechanismain,

side elevation. Fig. 3 is a detail viewof the oil-cup valve. Fig. 4 is a diagrammatic sectional view on line 4 4, Fig. 3. Fig. 5 is a front elevational view of the valve-casing and valve, the valve-cap being removed. Fig. 6 is a sectional view on line 6 v6, Fig. 5. Fig. 7 is a top plan view of the valve-casing. Fig. Sis a sectional view of part of the valve-casing, showing the valve in a position forexhausting pressurev from the cylinder. Fig. 9 is an inside face view of the valve. Fig. 10 is a cross-sectional View through said valve. Fig. 11 is a plan View of the valve, showing the same cooperating with the cylinder-port for exhausting pressure from the cylinder, said cylinder-port being shown in dotted lines. Fig. 12 is a similar View showing the valve in a different position. Fig. 13 is a sectional view through the valve-casing on' line 13 13, Fig. 6. Fig. 14 is an end view of the valve stem or spindle. Fig. 15 is a longitudinal sectional view of said stem or spindle. Fig. 16 -is a front elevational viewof a slightlymo ified form of the valve-operating mechanism. Fig. 17 is a side elevational view of the same; and Fig. 18 is asectional view on line 18 18, Fig. 17.

This invention relates to a new and useful improvement in pneumatic hoists, and more particularly the valve mechanism for controlling the admissionand exhaust of-compressed air to and from the cylinder. I The objects of my invention are to provide a valve which will remain tight after long use, to provide a simple and effective means" for lubricating said valve, the provision of a sensitive and quick-acting valve-operating mechanism wherein the valve is automatically returned to its neutralor non-operative position, and, finally, to so construct a valve which cooperates with the hoist in such mannor that said hoist may be stopped at any desired point.

With these objects in view the invention consists in the novel construction and arrangement of a pressure-actuated hoist in combination with a valve and valve-operat ing mechanism which automatically restores the valve to a central orclosed position when freed from restraint and which valve-operat ing mechanism is capable of operation by the hoist for. the purpose of self-regulation.

The invention also consists in the construction, arrangement, and combination of the several parts, all aswill hereinafter be described, and afterward pointed out in the claims.

In the drawings, A indicates the cylinder, provided with suitable heads, in the upper of which is introduced an eyebolt orhook a, by which'said cylinder may be suspended. The lower head is provided with a suitable studing-box, through which passes the rod b of the piston B. The lower end of rod 19 is provided with a spherical head I)", fitting in a socket c of a hook O. The opening in the socket through which the rod passes is of larger diameter thansaid rod, whereby the hook G has .a'pla'y in aILdirections on the head I), so that it may be said that hook C has a universal connection with the piston-rod. A loose cap 0. is on the rod above the socket 0, its under face being concaved to receive said socket, so as to prevent the entrance of dust, dirt, &c.

D indicates a valve-casing bolted to the leading from said valve-casing to the interior of the cylinder. A pipe e connects withthe inlet-port, in the upper end .ofwh'ichpipe pressure fluid is supplied by flexible or other pipe connection from a suitable source of pressure-supply. An exhaust-pipe 6 conducts the exhaust from chamber or port d to the exterior. I preferably head pipe 6' into a cross-chamber c, in turn connected wit the upper chamber of the cylinder, from which cross connection an opening 6' leads to the atmosphere.

An oil-cup E is preferably introduced into pipe 6 for the purpose of admitting a lubricant into the'supply-duct of the valve,whence it may be carried to lubricate the moving parts. The escape of the lubricant from cup E is controlled by a plug E, which, as shown in Fig. 3, is provided 011 opposite sides with grooves or recesses, whereby when said plug is rotated a small quantity of the lubricant will fill the recesses from the cup, after which when said plug is turned the quantity of oil so received in said recesses will be discharged from the opposite side of the plug. By this means a small quantity of oil can be admitted into the inlet-pipe.

E indicates a downwardly-openingcheck- Valve arranged in pipe e, whose function is to admit pressure to the cylinder; but should any of the pipes become disconnected between said check-valve and the source of supply the check-valve would prevent the piston from falling.

The chambers or ports (Z and d heretofore referred to terminate at a valve-seat, on which operates a disk valve F. This disk valve (shown more clearly in Figs. 0 and 10) consists, essentially, of two wings, one of which, f, is practically a blind wing and used to assist in centering the valve in its case, said wingfbeing preferably hollow on its under side, while the other wing, f, is practically solid and near one end thereof provided with a D-portf, which cooperates with a cylinder-port (1". Valve F is provided with a squared socket for receiving the end of a hollow stem or shank G, the hollow chamber g of which connects with the port f, while the other end of chamber 9 connects with chamher (1. Cap H is threaded or otherwise secured to the valve-casing for inclosing the valve F, and a spring is employed between said cap and valve for holding the valve to its seat in the absence of pressure. The port (1, which leads from the valve-chamber to the cylinder, is preferably controlled by a screw-plug I, acting as a throttle, whereby the available area for the admission and exhaust of the pressure to and from the cylinder may be controlled. A cap 1' is introduced over the plug I for well-known purposes. Port (1, where it terminates at the valve-seat, is provided with two oppositely-disposed leads x and ac, which cooperate with the valve to graduate the admission and exhaust of pressure to and from the port (1.

The operation of the valve may be briefly described as follows: Pressure being admitted through pipe 0 enters the chamber between the cap H and the valve-seat through the supply-duct d and fills said chamber with a constant pressure. Assuming the valve to be in the position shown in Fig. 12, port cl is closed and no pressure can enter or escape herethrough. However, when. Valve F is turned, say, in the direction of a left-hand rotation the first opening of port 01 to the pressure in the valve-chamber will be through the lead 00, which will gradually admit the pressure from the valve-chamber to the cylinder through said port. If the valve is held so that but a small area of leadwis available for the passage of pressure, it follows that the piston in cylinder A will rise slowly. If, however, the valve is thrown so as to make the entire port available to the passage of pressure, the piston will rise quickly. Assuming that the piston has made the movement desired, the valve is closed, as shown in Fig. 12, and if then it is desired to exhaust pressure from under the piston the valve is moved in a direction corresponding to a right-hand rotation or toward the position shown in Fig. 11. If a slow exhaust is desired, only the end of lead x is opened, which permits the pressure to escape through the ports f, g, d, and pipe 6 to the exterior. Should a quick exhaust be desired, the valve is turned to the full exhaust position. (Shown in Fig. 11.) The leads .90 and 00' by graduating the admission and exhaust of pressure to and from the cylinder makes it possible to control the movement of the piston within certain welldelined limits. Such slight admission orslight exhaust of pressure resulting in such a slow movement of the piston in either direction also makes it possible, due to the length of time consumed by the piston in making such slow movement, to automatically control the position of the piston commensurate with the variation of the-load it carries. It frequently occurs in the use of pneumatic hoists that the load varies, and with each variation of such. load the position of the piston varies accordingly. This perhaps is most striking where hoists of this character are used in handling ladles of molten metal in casting. A ladle full of metal is taken from the cupola and the pouring commenced. As the load in the ladle diminishes in proportion to the escape of metal from the ladle the expansive properties of the pressure fluid sustaining the weight will cause the piston to rise under a diminished load. It is desirable to control the expansibility of the pressure fluid under such conditions, and this control to be most effective must be sensitive to the movement of the piston, quick acting, and automatic. In Figs. 16, 17, and 18 I have shown such control, in which J indicates a collar slidingly mounted on the piston-rod b, but adapted to be clamped to said rod through the instrumentality of a screw 70, mounted in the hub of an operative handle K. This handle is preferably provided with chains or cords k at each end, whereby screw 7:, maybe rotated to bind or release the collar J from the pistonrod. L indicates a forked arm in engagement with collar J, said forked arm being mounted upon a rod M, introduced through a suitable opening in the valve-casing. A link N is mounted upon the upper end of rod M and tion.

connects at its other end to a rocking lever in the form of a handle 0, mounted upon the projecting end of the valve stem or spindle G,

which is preferably squared at this point to.

maintain the position of the piston, the collar- J is clamped to the piston when saidpiston is in the position it is designed to occupy, and as the piston is relieved of its load the expanding pressure fluid sustaining it will cause it to rise. This upward movement will actuate the lever through rod M and link N and turn valve F so that its port f registers with the port d and slowly exhausts pressure through lead 00. When the pressure in the cylinder equalizes the load, the parts will again assume their original position. If an additional load be put on the piston, the valve F will be rotated in the opposite direction to admit pressure under the piston.

It is important that means be provided to close valve F after operation in either direc- I have shown a novel mechanism for accomplishing this, consisting in chains or cords P, connected to lever O on each side of its pivotal point, the other ends of said chains or cords being connected to a ring or disk plate q, mounted on the lower end of a tension-spring Q. For the sake of convenience the upper end of spring Q is attached to a collar R, adjustably mounted on pipe 6, for regulating the tension of the spring. The normal position of the parts is illustrated by dotted lines in Fig. 1 and in full lines the position the parts assume when the chain 0 on the right-hand end of lever O is pulled. It will be noted that the tension of spring Q is alwaysexerted to return the lever to its normal position, the chain on that side of the lever which is depressed being taut, while the other chain, connected to the other or idle side of the lever, is slack. When the lever is released, the tension of spring Q is sufficient to restore the lever to its normal position and in so doing rotate the valve to a lap position.

In Figs. 1 and 3 I have shown the rod with a collar J and arm L connected to a rod M, which rod carries a pin m for operating lever 0 in one direction to close the valve when the piston reaches a certain height and lock lever 0 against further opening, but permitting exhaust movement. A thumb-nut 7c is employed for clamping the collar to the pisston-rod. This construction admits of a semiautomatic control of the pressure, while the construction shown in Figs. 16 to 18 admits of a full automatic control.

I am aware that minor changes in the arran gement, construction, and combination of Y several parts of my device can be made and substituted for those herein shown and described without in the least departing from the nature and principle of my invention.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In a pneumatic hoist, the combination with the cylinder and its piston, of a valvecasing, a disk valve operating therein, a port 01, controlled by said disk valve, and a stem on which said valve is mounted, said stem being formed with an exhaust-passage; substantially as described.

2. In a pneumatic hoist, the combination with the cylinder and its piston, of a valvecasing, a disk valve operating therein, a port d having leads or and or, controlled by said disk valve, and a stem on which said valve is mounted, said stein being formed with an exhaust-passage; substantially as described.

3. The combination with a valve-casing to open the same to pressure from the valvechamber, and said valve being provided with sate for an increase or decrease in the load I carried by the piston, said means comprising a spring-actuated lever arranged on the valvestem, a rod for operating said lever, a collar to which said rod is connected, and a clamping-screw in said collar; substantially as described.

5. In a pneumatic hoist, the combination with the cylinder and its piston, of a valve for admitting and exhausting pressure to and from said cylinder, and means capable of being clamped to the piston at different points for operating said valve to admit or exhaust pressure to and from the cylinder to compensate for an increase or decrease in the load carried by the piston, said means comprising a lever 0 arranged on the valve-stem, a link N, connected to said lever, a rod M, to which the other end of said link is connected, an

arm L on rod M, a collar .I on the piston-rod,

with which collar the arm L engages,abindingscrew 70 in the collar, and a handle K on said binding-screw; substantially as described.-

6. In a pneumatic hoist, the combination with the cylinder and its piston, of a valve for admitting and exhausting pressure to and from said cylinder, a lever attached to the valve-stem for operating the same, flexible connections on each side of the pivotal point of said lever, and means for holding said connections normally taut and restoring the lever to its normal position; substantially as described.

7. In a pneumatic hoist, the combination with the cylinder and its piston, of a valve for admitting and exhausting pressure to and from said cylinder, a lever attached to the valve-stem for operating the same, flexible connections on each side of the pivotal point of said lever, and a tension-spring to which said flexible connections are attached; substantially as described.

8. The combination with lever O, of cords or chains P, connected thereto, on each side of its pivotal point, a spring Q, to which the other ends of said cords or chains are connected, and an adjustable support R for regulating the tension of said spring; substantially as described.

9. In a pneumatic hoist, the combination with the cylinder and its piston, of a valve for admitting and exhausting pressure to and from said cylinder, a lever attached to the valve-stem for operating the same, flexible connections on each side of the pivotal point of said lever, and mechanism capable of being clamped to the pistonrod at dilferent points for cooperating with said lever and moving the valve to its neutral position, and also locking the lever against furtheropening movement,and permitting exhaust movement when the piston rises above its designed position.

10. In a pneumatic hoist, the combination with the cylinder and its piston, of a valve for admitting and exhausting pressure to and from said cylinder, a lever attached to thevalve-stem for operating the same, flexible connections on each side of the pivotal point of said lever, and means capable of being clamped to the piston at dilferent points for operating said valve to admit or exhaust pressure to and from the cylinder to compensate for an increase or decrease in the load carried by the piston, whereby, said piston is maintained in a designed position under varying loads; substantially as described.

11. In a pneumatic hoist, the combination with the cylinder and its piston, of a valve for admitting and exhausting pressure to and from said cylinder, a lever attached to the valve-stem for operating the same, flexible connections on each side of the pivotal point of said lever, and means capable of being clamped to the piston at different points for operating said valve to admit or exhaust pressure to and from the cylinder to compensate for an increase or decrease in the load carried by the piston, said means comprising a lever arranged on the valve-stem, a rod for operating said lever, a collar to which said rod is connected, and a clamping-screw in said collar; substantially as described.

12. In a pneumatic hoist, the combination with a valve-casing formed with an inlet and exhaust port, of a valve for controlling said ports, a cylinder-port, a threaded plug I'forming a throttle-valve for controlling the available area of said cylinder-ports, and a cap i, threaded upon the outer end of said throttlevalve, and acting as a jam-nut to lock the same in its adjusted position; substantially as described.

13. In a pneumatic hoist, the combination with a valve-casing formed with inlet and exhaust ports, of a valve cooperating therewith, a cylinder-port, the valve-casing on opposite sides of said cylinder-port being formed with threaded openings in alinement with each other, and a threaded plug fitting in one of said openings and adapted to be closed by being received by the other opening; substantially as described.

14. The combination with a valve-casing formed with a pressure-supply duct d, an exhaust-passage d, and a cylinder-port d", of a disk valve cooperating with the cylinder-port to open the same to pressure from the valvechamber, and said valve being provided with a passage f for registry with the cylinderport, a valve stem or spindle formed with a passage g, in constant register with the passages dandf, means connected to said spindle for rotating said valve and restoring the valve to a non-operative position, said means comprising a lever O, cords or chains P connected thereto on each side of its pivot-point, and a spring Q, to which the other ends of said cords or chains are connected; substantially as described.

In testimony whereof I hereunto affix my signature, in the presence of two witnesses, this 8th day of June, 1899.

GEORGE F. S'lEEDHAN.

Witnesses:

F. R. CORNWALL, A. S. GRAY.

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