US796375A - Fluid-pressure-operated tool. - Google Patents

Description

No. 796,375. PATENTBD AUG. 1, 1905.

11.11. VAUGHAN.

FLUID PRESSURE OPBRATED TOUL. APPLIOATION FILED Nov. 19. 1902. RENHWED JUNE 24,1905.

UNITED STATES PATENT OFFICE.-

HENRY H. VAUGHAN, OF CLEVELAND, OHIO, ASSIGNOR TO RIDGELY AND JOHNSON TOOL COMPANY, A CORPORATION OF ILLINOIS.

FLUID-PRESSURE-OPERATED TOOL Specification of Letters Patent.

Patented Aug. 1, 1905.

Application filed November 19, 1902. Renewed June 24, 1905. Serial No. 266,851.

To all 11172/0711, it 77mg/ concern:

Be it known that I, HENRY H. VAUGHAN, a citizen of the United States, residing at Cleveland, county of Cuyahoga, State of Ohio, have invented a certain new and useful Improvement in Fluid-Pressure-Operated Tools; and I declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates generally to fluid-pressure-operated tools, and more particularly to valve mechanism controlling the admission and exhaust of fluid-pressure to the cylinder.

In fluid-pressure'tools it is desirable that the valve controlling the supply and exhaust of pressure to the ends of the cylinder should be operated to cut ofl the supply from the respective sides of the piston before it reaches the end of its stroke, and it is also desirable that the valve should be quickly shifted from one position to the other and when shifted positively held by a preponderance of pressure in each position until the piston reaches the predetermined point in its stroke, when the supply and exhaust of fluid-pressure to the respective ends of the cylinder should be reversed.

An object of my invention is to provide a fluid-pressure-operated tool in which the supply and exhaust of pressure to the respective ends of the cylinder are controlled by a pistonvalve the reciprocation of which to its controlling positions will be quickly and certainly accomplished and which when shifted will be firmly held in each position until again shifted by the piston reaching the proper predetermined point in its throw.

A further object of my invention is to provide in a fluid-pressure-operated tool a valve mechanism of the same type as that covered by my application, Serial No. 131,945, filed November 19, 1902, for controlling the supply and exhaust of iuid pressure to the opposite ends of the cylinder, comprising adifferential piston-valve which will be retained in position to admit Huid-pressure to one end of the cylinder by the pressure of fluid exhausting from the other end of the cylinder.

A still further object of my invention is to provide a uid-pressure-operated tool of the character referred to which will be simple in construction, inexpensive in manufacture, an eficient in operation.

- The embodiment of my invention herein disclosed generally described consists in a valve mechanism comprising a valve-casing having separate ports for the supply of motive Huid to and the exhaust of fluid from the back or working end of the cylinder and a single port communicating with the front end of the cylinder, through which fluid is both supplied and exhausted, and a differential piston valve which lis held in position to close the supplyport to the back end of the cylinder by the pressure of fluid which passes through the exhaust-port from the back end of the cylinder. By providing separate supply and exhaust ports leading to the back end of the cylinder the piston may be cushioned by closing the exhaust-port before it reaches the limit of its back stroke, while, on the other hand, motive fluid may be admitted to the working end of the cylinder through the separate supply port or ports, even though the piston in its back stroke closes the exhaust-port leading from the back end ofl the cylinder'.

My invention will be more fully described hereinafter with reference to the accompanying drawings, in which the same is illustrated as embodied in a convenient and practical form, and in which4 Figure 1 is a horizontal central section through the cylinder with the piston and die therein shown in plan. Fig. 2 is a cross-sectional view on an enlarged scale, showing the valve mechanism; and Fig. 3, a view similar to Fig. 2, showing the valve in section and in a position opposite to that shown in Fig. 2.

Similar reference characters are used to indicate similar parts in the several figures of the drawings.

Reference-letter A indicates the handle of' the tool, which may be of any suitable construction, in the present instance the same being shown as provided with a tubular extension A, surrounding the back end of the cylinder C. The handle may be secured to the cylinder by any suitable means-such, for instance, as an inwardly-extending circular liange A3, formed within the extension Al and adapted to be engaged between the end of the cylinder C, and a :iange formed on the cylinderhead CQ as clearly shown in Fig. 1.

' AAi indicates a lever for unseating a throttlevalve. The latter, however, is not shown, as the same forms no part of my present invention.

The cylinder C is provided with a bushing c, one end of which is engaged by the tubular projection C2 of the cylinder-head C. The part C2 is preferably exteriorly screw-threaded to engage screw-threads formed within the end of the cylinder C, and thereby retain the cylinder-head, as well as the handle A, in position on the cylinder. The end C3 of the cylinder is interiorly screw-threaded and is engaged by a ferrule G. A snap or die H is removably supported within the ferrnle Gr, in which it is yieldingly retained by means of a spring-ring g, seated within an annular groove formed in the interior surface of the ferrule. The shank of the die H is reduced, as shown at li, thereby forming shoulders to serve as stops tolimit the movement of thedie through engagement with the spring-ring g.

A cylindrical valve-casing A2 is located transversely beneath the back end of the cylinder and is preferably formed integrally with the handle A. rlhe ends of the valve-casing may be closed by any suitable means such, for instance, as screw-threaded caps A5. The valve-casing is provided with a series of annular grooves, with which communicate ports a. a2, a3, and a4, registering with ports c, C2, c3, and c4, formed in the cylinder C. An annular supply-passage a is formed near 'the center of the Valve-casing and communicates with the source of Huid-pressure, such communication being controlled, as is customary, by a throttle-valve of any desired construction. An exhaust-port a leads tothe atmosphere from an annular groove formed in the valve-casing A2 at a point intermediate of the suppl y-passage a and the annular groove with which the port o2 communicates. Another exhaust-port a leads to the atmosphere from an annulargroove formed in the valve-casing ata point intermediate of the annular grooves, with which communicate the ports a3 and a". The port c is extended in the form of a passage which communicates with the interior of the back end of the cylinder at a point a short distance from the end of the bushing c. as shown in Fig. 1. The port c2 communicates with a passage leading' to a point c2 within the cylinder slightly farther away from the front end thereof than the length of the piston K.

The port 03 is extended in the form of a pasportion C2 of the cylinder-head C is greater than the diameter of the piston fluid-pressure may be exerted upon the end of the pistonwhen the same extends beyond the end of the bushing and within the tubular portion C2 of the cylinder-head.

A'bushing E is located vwithin the valve- 1 casing A2 and is retained therein by means of the screw-threaded caps A5. The bushing is provided with a series of ports e, e, e2, e3, e4, e5, and e, which register with the corresponding ports a, a, ft2, co3, c, co5, and a, formed in the valve-casing. A differential valve D is located within the bushing and controls the ports therethrough. The end D of the valve is hollow and is provided with ports CZ, con# necting the exterior surface of the valve with the hollow interior. rIhe opposite end of the valve D2 is reduced in diameter and is provided with a hollow interior which extends inwardly to a point adjacent to the chamber formed in the end D of the valve, as clearly shown in Fig. 3. vA superficial annular groove d is provided at a point near the center of the valve and communicates, by means of radial ports (Z2, with the hollow interior of the reduced end D2 of the valve. The end of the bushing E within which reciprocates the smaller end D2 of the valve is reduced in bore, so as to closely engage the exterior surface of the smaller end of the valve. The interior diameter of the opposite end of the bushing is also slightly reduced by means of a lining E, which closely engages the exterior surface of the end portion D of the valve. The central part D3 of the valve is of a slightly greater diameter than the end portion D' and closely engages the bushing intermediate of the lining E and the reduced bore at its opposite end. Restricted ports Z3 lead from the exterior of the end portion D of the valve at points adjacent to the enlarged central part D3 to the inner end of the chamber, which extends through the valve to the end D2 thereof.

The several parts of the mechanism of the valve may be readily assembled and the valve easily removed when desired from the bushing, `owing to the screw-threaded engagement between the caps A5 and the ends of the valvecasing A2.

The operation of my invention is as follows: When the Valve is in the position indicated in Fig. 2, motive fluid passes from the supplyport e through the restricted ports (Z3 into theV chamber, which extends through the smaller end D2 of the valve, and thence through the ports d2, e3, a3, and @Sinto the front end of the cylinder, thereby moving the piston toward the bach end of the cylinder. The back end of the cylind er at such time communicates with the atmosphere through the following ports and passages: 0, a, e, d, e5, and 05. The valve is retained in the position shown in Fig. 2 by reason of the pressure of the exhausting fluid exerted upon the surface of its larger end D', the area of which is greater than the area of the opposite end D2 of the Valve, which is constantly exposed to pressure flowing through the restricted ports @Z3 from the supplyport a. The shoulder formed by the difference in diameter between the central portion D3 and the end portion D of the valve also `tends to retain the valve in position shown in Fig. 2. /Vhen the pressure exerted upon the end D' of the valve is sufficiently reduced by exhaust to the atmosphere, the valve is moved to the position shown in Fig. 3 by reason of the pressure exerted on its reduced end D2. The restricted ports Z3 insure a sufciently slow return of the piston to the back end of the cylinder to permit the exhaust of the fluid from the back end of the cylinder until the port c is closed by the piston. The shoulder between the central portion D3 and the end D of the valve insures the retaining of the valve in the position shown in Fig. Q until the exhaust through the port c/ from the back end of the cylinder has been completed. When the valve is in the position shown in Fig. 3, motive fluid is admitted to the back end or working end of the cylinder through the following ports or passages, a, e, CZ, (Z2, e4, at, and 0*, thereby forcing the piston toward the front end of the cylinder, where it delivers a blow upon the shank. of a tool or upon a snap or die yieldingly retained in the front of the cylinder in position to receive the impact of the piston. When the piston in its stroke toward the tool uncovers the end of the passage c5, liuid passes through the ports c2, e2, e2, and CZ' and is ex# erted upon the surface of the larger end D of the valve. The valve is consequently moved from the position shown in Fig. 3 to that shown in Fig. 2, owing to the area of the end D being' greater than that of the end D2, the latter being constantly exposed to fluid-pressure passing through the supply-port a.

By providingl a separate port 0/ for the exhaust of fluid from the back end of the cylinder the exhaust may be discontinued before the piston reaches the limit of its back stroke, so as to cushion the piston. By providing a series of graduated ports ci separate from the exhaust-port c motive fluid may be admitted to the back or working end of the cylinder,

even though the exhaust-port c is covered by the piston. By graduating the series of ports c" so that they increase in size as they are successively uncovered by the piston in its stroke toward the front end of the cylinder impetus is added to the velocity of the movement of the piston.

From the foregoing description it will be observed that I have invented a fluid-pressureoperated tool in which the valve is retained in position to cut off the supply of motive fluid to the back end of the cylinder by the pressure of the fluid exhausting from the back end of the cylinder, the valve being automatically moved into position to open communication with the back end of the cylinder upon the discontinuance of the flow of the exhausting pressure therefrom.

vWhile I have described more or less precisely the details of construction, I do not wish to be understood as limiting myself thereto, as I contemplate changes in form, the

proportion of parts, and the substitution of equivalents as circumstances may suggest or render expedient without departing from the spirit of my invention. I do not, however,claim in this application the generic invention ernbodied in the structures disclosed herein and also disclosed in my copending application, Serial No. 131,945, filed November 19, 1902, inasmuch as the generic invention common to this application and to the copending' application referred to is generically claimed in said copending application, and I only desire to claim in this application the features of construction not disclosed in said copending application.

Having now fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In afluid-pressure-operated tool, the combination with a cylinder, of a reciprocating piston therein, a valve-casing having separate ports for the admission and exhaust of motive fluid to one end of the cylinder, a piston-valve located in said casing, controlling the supply and exhaust of fluid-pressure, said cylinder and valve-casing having ports and passages where-by said valve is retained in position to close the admission-port to one end of the cylinder by the pressure of fluid passing through the exhaust-port from the same end of the cylinder.

2. In afluitl-pressure-operated tool, the combination with a cylinder, of a reciprocating piston therein, a valve-casing' having a series of graduated ports through which motive fluid is admitted to one end of the cylinder and an exhaust-port leading from the cylinder at a point a predetermined distance from said end thereof, a piston-valve located in said casing, controlling the supply and exhaust of iiuidpressure, said cylindervand valve-casing having ports and passages whereby said valve is retained in position to cut olf the flow of fluid through said admission-ports by the pressure of iluid passing through the exhaust-port from the same end of the cylinder.

3. In afluid-prassure-operated tool, the combination with a cylinder, of a reciprocating piston therein, a valve-casing having separate ports for the admission and exhaust of motive fluid to the back end of the cylinder, and a single port communicating with the front end of the cylinder through which fluid-pressure is both admitted and exhausted, a piston-valve located in said casing controlling the supply and exhaust of iiuid-pressure, said cylinder and valve-casing having ports and passages whereby the said valve is retained in position to close the admission-port to the back end of the cylinder by the pressure of the iiuid passing through the exhaust-port from the back end of the cylinder.

4. In a iluid-pressure-operated tool, the combination with a cylinder, of a reciprocating' piston therein, a valve-casing having a series of graduated ports through which motive fluid is admitted to the back end of the cylinder, and a separate exhaust-port leading from the cylinder at a point a predetermined distance from the back end thereof` and also having a single port communicating with the front end of the cylinder, throughwhich Huid-pressure is both admitted and exhausted, said cylinder and valve-casing having ports and passages whereby said valve is retained in position to close the series of admission-ports to the back end of the cylinder and to admit pressure to the front end ofthe cylinder by the pressure of the fluid passing through the exhaust-port from the back end of the cylinder.

5. In auid-pressure-operated tool, the combination with a cylinder, of a reciprocating' piston therein, a valve-casing having an exhaust-port leading from a point within the cylinder a predetermined distance from one end thereof, and an admission-port communicating with the cylinder at a point between the end thereofl and said exhaust-port, and a piston-valve located in said valve-casing alternately opening and closing said ports, whereby pressure may llow through the admission-port to the cylinder when the piston therein closes the exhaust-port therefrom.

6. In ailuid-pressure-operated tool, the combination with a cylinder of a reciprocating piston therein, a valve-casing' having ports communicating with the opposite ends oi the cylinder, a differential piston-valve located in said casing controlling' the supply and exhaust of Huid-pressure, said valve having open chambers within its opposite ends through one of which Huid-pressure alternately passes to the opposite ends of the cylinder, and through the other of which exhaust liuid passes from one end of the cylinder.

7. ln a[iuid-pressure-operated tool, the combination with a cyllnder ol' a reciprocating piston therein, a valve-casing' having supply and exhaust ports and por-ts leading to the opposite ends of the cylinder, a differential piston-valve located in said casing having open chambers within its opposite ends, said-valve in one position adapted to connect the supplyport with the front end of the cylinder through the open chamber in one lof its ends, and to simultaneously connect the exhaust-port with the back end of the cylinder through the open chamber in its opposite end, and adapted in its opposite position to connect the supplyport with the back end of the cylinder through the open chamber in one of its ends, and to simultaneously place the front end of the cylinder in communication with an exhaust-port through the annular space between the exte rior surface of the valve and the interior surface of the casing.

8. ln a fluid-pressure-operated tool, the combination with a cylinder', of a reciprocating piston therein, a valve-casing' having supply and exhaust ports and ports leading to the opposite ends of the cylinder, a differential piston-valve in said casing having an open interior chamber and radial passages of different sizes leading' to said chambers from the exterior 'surface of the valve, said valve in one position adapted to connect the supply-ports with the front end of the cylinder through said chamber and the smaller radial passages, and in its other position to connect the supply-port with the back end of the cylinder through said chamber and the larger radial passages, said cylinder and valve-casing' having ports and passages whereby said valve is retained in its lirst position by the pressure ol' fluid exhausting from the back end of the cylinder.

1n testimony whereofl I. sign this speciication in the presence ot' two witnesses.

HENRY H. VAUGHAN. lvitnesses:

PAUL C. CADY, ERNusT (l. Bowne.

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