US818284A - Fluid-actuated valve. - Google Patents

Description

PATENTED APR. 17, 1906.

W. 0. PELHAM. FLUID AGTUATED VALVE.

APPLICATION FILED JUNE 14, 1905.

3 SHEETS-SHEET 1.

PATENTED APR. 17, 1906.

3 sums-SHEET 2 W. O. PELHAM. FLUID AGTUATED VALVE. APPLICATION FILED JUNE 14, 1905.

PATENTED APR. 17, 1906.

W. 0. PBLHAM.

FLUID AOTUATED VALVE.

APPLICATION FILED JUNE 14, 1905.

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UNITED STATES WALTER PATENT FFIGE.

TO PLES F. FERGUSON, OF MONETT, MISSOURI.

FLUlD-"AQTUATED VALVE.

Specification of Letters Patent.

Patented April 1'7, 19060 Application filed June 14,1905. Serial No. 265,287.

' To all whom it may concern:

\ Be it known that I, WALTER O. IELHAM, a citizen of the United States, residing in lVIonett, in the county of Berry and State of Missouri, have invented certain new and use ful Improvements in Fluid-Actuated Valves, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

This invention relates to a new and useful improvement in air-pumps, and relates particularly to that class of pumps employed in air-brake systems of railway rolling-stock.

The objects of the invention are to eliminate certain objectionable features which I have found by actual experience to exist in the now usually employed pumps and to simplify its construction, whereby repairing is more easily accomplished. In air-pumps of this character with which I am familiar the objectionable features which I claim to have eliminated are, first, dispensing with the reversing-valve rod and reversing-valve plate, which frequently become bent, loosened, or broken, causing the valve to partially or wholly fail to perform its proper function or causing a premature reversal thereof; second, to dispense with the hollow piston-rod, whereby a stronger and less expensive rod is employed, and, finally, by the construction of my valve it is unnecessary to remove the head of the pump from its cylinder to make repairs.

The essential features of my invention reside, first, in the construction which provides for a positive mechanical operation of the reversing-valve in one direction of movement only, said reversing-valve being fluid-thrown in its opposite movement; second, in the construction shown, wherein all parts of the valve mechanisms are contained within the cylinderhead, whereby all repairs can be made without having to remove said head from its cylinder.

Other features of the invention reside in the novel construction, arrangement, and combination of the several parts, all as will hereinafter be described and afterward ointed out in the claim.

In the drawings, wherein like characters designate like parts throughout the several views, Figure I is a vertical longitudinal sectional view of a well-known air-pump having my invention applied thereto. Fig. II is a vertical longitudinal sectional view taken at right angles to Fig. I. Fig. III is a horizontal sectional .view taken on line III III, Fig. I. Fig. IV is a horizontal sectional view taken on line IV IV, Fig. III. Fig; V is a detail perspective View of the reversingvalve-chamber bushing. Fig. VI is a detail perspective view of the reversing 'valve proper. Fig. VII is an end elevational view of the main-valve bushing. Fig. VIII is a side elevational view of the same. Figs. IX and X are diagrams illustrating the two positions of the main valve, reversing-valve, and their associate parts.

A designates the steam cylinder, B B the top and bottom cylinder-heads, respectively, C the piston-rod, D the piston, E the main slide-valve, and F and X the admission and exhaust ports, respectively, all of which parts are of well-known construction.

- 1 designates a port which leads from the top of the reversing-valve casing to a point 2 within the steam-cylinder, its terminus in said cylinder being preferably just above the piston D when the latter is in its lowermost position. (See Figs. I and II.)

3 designates what I will term the reversing-valve casing, which is preferably formed integral with the cylinder-head B, said casing containing a cylindrical bore. which receives a bushing 4, and within the cylindical bore formed in said bushing is arranged the reversing-valve which consists of two pistons 5 and 6, formed on a rod 7, and interposed between these pistons 5 and 6 and partially sur rounding said rod 7 is a slide-valve 8, which latter contains a port or recess 9.

6 indicates what I shall term a steampassage, which is located between the valve 8 and the piston 6. This slide-valve 8 is guided and held against independent movement of the pistons 5 and 6 and the rod 7 by a pin 10, which works in a slot therein, said in being secured in any suitable manner to the bushing L and valve-casing, as is clearly shown in Figs. II and III.

11 designates the lower and larged end of the rod 7, which is designed to pass through a bore formed in the lower end of the bushing 4 and in its lowermost position protrudes some distance into the steam;-

preferably encylinder A and is designed to be struck upon the upward movement of the piston D to mechanically operate the reversing-valve. This enlargement is preferably provided with an expansible packing-ring 12 for obvious reasons.

The reversing-valve bushing 4 (see Figs. II and V) is provided with ports 13, 14, 15, and 16, the three former of which are formed in vertical alinement with each other and are simply perforations which establish communication between the bore of bushing 4 and other ports hereinafter to be described. The port 16 consists of a groove 17, formed in the exterior peripheral face of the bushing 4, which groove starts at a point in vertical alinement with ports 13 14 15 and leads to a point almost diametrically opposite, thence downwardly in preferably a vertical direction, as indicated by 18, and finally terminates in the bore of bushing 4 by a port 19.

20 designates a port in the form of a groove which establishes communication with the extreme lower end of the bore of the bushing 4 and the port 18, which latter is an exhaustport and at all times open to atmosphere and by which construction pressure fluid is permitted to pass from beneath the piston 6 when it descends.

The main slide-valve E, which is best illus trated in Figs. II, III, and IV, is of a wellknown construction and will only be described tersely. This valve consists of a rod a, upon the ends of which are arranged pistons b and c, the former being the smaller in diameter. These pistons operate in suitable bores d and 0, respectively, formed in the head of the valve-casing and the main-valve bushing f. g designates a slide-valve located between the pistons I) and c and is operated thereby, together with the rod a. This mainvalve bushing is also provided with the usual ports h, 'L, j, and 7c, the latter of which is at all times the exhaust-port and communicates with the final exhaust-port X of the steamcylinder, while the former communicates with the admission-port F thereof. The ports i and conduct pressure fluid to and from the lower and upper ends, respectively, of the steam-cylinder by suitable passage-ways or ports Z and m, formed in said steam-cylinder and its head. This main valve is also provided with the usual ports n, 0, p, and the latter of which communicates with the ex haust-port 7c, while the former of which, n, is at all times in communication with the interior of the main-valve bushing f and is in registration with and is designed to conduct pressure fluid to the port 16 of the reversingvalve bushing 4, the ports 0 and p being likewise in registration with the ports 14 and 15 of said reversing-valve bushing 4, said ports 0 and p being also in communication with the bore e of the main-valve bushing in advance of the piston c.

The operation of the device is as follows: Steam or other pressure fluid, being admitted through the port F, passes through the port h into the main-valve bushing f, and when the parts are in the position shown in Figs. I, II, III, IV, and IX of the drawings said steam is conducted to the under side of the piston D through the ports i and Z, whereupon it will cause said piston to rise, said piston finally coming in contact with the lower end of the portion 11 of the reversing-valve and raising the same a suflicient distance to cause the steam-space 6 to register with the port 15 and cause the port 9 of the slide-valve 8 to establish communication between ports 13 and 14. The interior of the reversing-valve casing between the pistons 5 and 6 at all times has a constant pressure of steam which is supplied thereto by the ports m, 16, 17, 18, and 19. Hence when the reversing-valve is moved to the position just described'i. e.,in its upward positionit is permitted to pass through ports 15 and p to the bore 6 in the main-valve bushing in advance of the piston c and cause the same to be thrown to its opposite positionin this instance, when the drawings only are considered, to the left. This action is accomplished by the differential pistons b and c for the reason that when steam is admitted in advance of the piston c it balances the steam-pressure on the'other side of said piston, whereby the face of the smaller piston b is acted upon by the steam and causes the valve to move to the left. This movement of the main valve causes the slidevalve 9 to reverse the steam action to drive the piston downwardly, as is well understood. We now have the parts in the position illustrated in Fig. X, where they will remain until the piston D descends and puts the port 2 in communication with the steam above the piston-head, whence said steam will pass through ports 2 and Z to the interior of the reversing-valve casing above the piston 5, forcing the same downwardly into the position shown in Figs. I, II, III, IV, and IX of the drawings, wherein it will be seen that the main valve has been moved to the right due to'the differential pistons b and 0, because the port 9 of the slide-valve of reversing-valve establishes communication between the bore 6 of the main valve and the exhaust and due to the difference in area of the valves 6 and C causing the two to move to the right by the pressure of steam therebetween.

I claim as my invention In a device of the character described, the combination with a cylinder and its piston, of a main valve associated therewith, a reversing-valve casing, a reversing-valve consisting of two pistons having a slidevalve interposed between said pistons, and a depending portion carried by said last-mentioned piston and said slide-valve, which depending portion extends into the steam-cylinder and is inv the path of movement of said first-mentioned piston and is susc thereby; ports for effecting eptible of being moved said valve-casing having suitable the movement of said main valve after said reversing-valve has been mechanically der and valve-casing operated, and said cylinbeing provided With a port for causing said reversing-valve to be WALTER O. PELHAM.

In presence of FRANK BURNS. C. S. MQOANE.

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