US714604A - Method of actuating valves of liquid-pumps. - Google Patents

Description

P atented Nbv. 25.19021. 6. B. FETSBHE.

METHOD OF AGTUATING VALVES 0F LIQUID PUMPS. [Application filed July 19, 1902.]

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No. 7|4,604. Patented Nov. 25, I902 w GQB. PETSCHE.

METHOD AGTUATING VALVES 0F LIQUID PUMPS. (Appliiation filed July 19. 1902.) (No Model.) 3 Sheets-Sheet 2,

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METHOD OF ACTUATING VALVES OF'LIGUID PUMPS.

' (Application filed July 19, 1902.]

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GUSTAV B. PETSCHE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE SOUTHWARK FOUNDRY & MACHINE COMPANY, OF PHILADEL- PHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

METHOD OF AOTUATING VALVES OF LIQUID-PUMPS.

SPECIFICATION forming part of Letters Patent No. 714,604, dated November 25, 1902.

Original application filed July 31, 1897, Serial No. 646.629. Divided and this application filed July 19, 1902. Serial No. 116,203. (No model.)

T at whom it may concern.-

Be it known that I, GUSTAV B. Parsons, a subject of the Emperor of Germany, residing in the city and county of Philadelphia, in the State of Pennsylvania, have invented a certain new and Improved Method of Actuating Valves of Liquid-Pumps, of which the follow- I ing is a true and exact description, reference actuating valves of liquid-pumps July 31,

1897, Serial No. 646,629.

I-Ieretofore pumps for water and other liquids have usually been made with valves of the type generally known as clack or puppet valves, said valves being generally held to their seats byspring-pressu re, and elevated therefrom,to permit the exhaust of water from the pump-chamber, by the pressure of the Water. Inlarge pumps it is found necessary to provide a very large number of such puppetvalves, which valves in use give rise to con siderable and serious trouble, not only from the noise which they make in closing and from the fact that they are frequently broken or out of order, but also because when open they lie immediately in front of 'the port through which the water issues and greatly impede its flow. I 1

Prior to my invention attempts have been made to use slidevalves, with the object of avoiding the noise of the clack-valves and of giving a freely-open port for the passage of water; but for the most part such attempts have proved unsuccessful, owing to the difficulty of opening sliding valves at the critical moment when the valve should theoretically it openthat is. to say, at the time when the pressure within and without the pump-chambers is the sameand of course to a certain extent the same difficulty prevailed as to the closing of the valve, which should take place at the end of the compression-stroke of the plunger in the pump, and which, if deferred,

In the patent of William E. Good, No.-

507,582, of October 31, 1893, a pump is shown and described in which slide-valves. are designed to be used and in which the inventor aimed to overcome and did to a certain extent overcome the difficulties I have noted by providing for a movement of the slidevalve to and from its seat, so that the-valve, at the beginning of the expulsion-stroke of the plunger, rises from its seat, so as to permit the flow of water around its edges during the time in which the positively-actuating mechanism was shifting it sidewise to open its controlled ports; but this construction gave so much freedom of motion to and from the seat of the valve as to produce an objectionable hammering, and did not at all provide for a not-infrequent occurrenceto wit, the presence of air in the cylinder of the pump, which, when it occurred, resulted in the powerful application of the positively-moving mechanism to open the delivery-valve before the water in the pump-chamber was ready to how out, in consequence of which the opening of the valve had to be accomplished against the greatly-preponderating pressure in the main acting to hold the valve to its seat, and the 7 strains thus put upon the valve and its actuating mechanism were dangerousand notiin practice permissible.

The object of my invention is to provide a method for operating valves in pumps by means of which the difficulties heretofore met with can be and are entirely overcome, and by means of which the opening of the valve can be, and is, effected automatically at the critical point when the pressures upon both sides of it are equal or approximately equal, and I accomplish this by making use of the resistance developed by the pressure of the valve upon its seat during the period when the pressure upon one side is greater than that upon its other side, and by providing an elastic or yielding actuating force to operate the valve,

- which force is brought into action upon the valve at or preferably slightly before the point in the motion of the plunger at which the valve should theoretically move, but which only actually moves the valve when the resistance holding it to its seat is over- I come or diminished to a determined point,

' method, which is applicable in part to the opcry-valves, and A A seats of the suctioneration of puppet-valves as well as sliding valves.

Referring now to the drawings, in which I have illustrated pump constructions adapted to embody and utilize my method, Figure 1 is a diagrammatic illustration of a twin quarfer-crank double-acting pumping-engine. Fig. 2 is a sectional illustration of mechanism for supplying pressure fluid to the valve-actuating cylinders and for regulating the admission and exhaust of such pressure fluid. Fig. 3 is a sectional illustration illustrating a simple modification of the devices for applying my method to the control of pump-valves and Fig. 4, a sectional elevation illustrating the application of my method to a pump provided with puppet-valves, all of said illustrative figures being embodied in the drawings of my original application, Serial No. 646,629, and, so far as the same present features of mechanical novelty, covered in the claims of said original application.

A and A indicate pump-chambers in which the plungers (indicated by the symbol 0) operated by their piston-rods (indicated at C) operate.

A A 850., indicate the seats of the delivvalves. I

A A 850., indicate the suction-chambers of the pumps; A A &c., the delivery-chambers of the pump, B B indicating supplymains, and B B, &c., the delivery-mains.

D D, &c., indicate the delivery-valves, D

'D, &c., the suction-valves, D D &c., indieating the actuating valve-rods, and D D Figs. 1 and 4, indicating connecting valverods coupling the delivery-valves in one pump-chamber with the suction-valves in the corresponding chamber of a double-acting pump. This connection is an appropriate one, because under normal conditions the two valves should open and close together.

F F, &c., Figs. 1 and 4, indicate valve-actuating cylinders provided with ports F F leading from their tops'and bottoms, and in these cylinders work pistons (indicated at G G, 850.) which are connected to valve-rods D to actuate them and the connected valves.

H, Fig. 2, and h h, Fig. 4, indicate valvecasings for the pilot or controlling valve which regulates the admission and exhaust of pressure fluid to the cylinders F. As shown in Fig. 2, the casing has a cylindrical valvechamber into which lead the ports F F, also a port it for the supply of fluid under pressure, which is connected with a supply-main (indicated at b and which is conveniently the main supplied by the pump.) it h are exhaustports also leading into the cylinder H and connected with the exhaust-conduit, (indicated at H I indicates a piston-valve working in the cylindrical casing and having two separated cylindrical surfaces, (indicated at I and I I is the piston-valve rod,havingacam-yoke (indicated at 1 upon its end, in which is situated a cam L, secured to a shaft L, which in the construction illustrated will of course be a rock-shaft and which shaft or other actuating device for the valve should in all cases be a positively connected and operating part of the pumping-engine.

In the construction shown in Fig. ithe ports F and F lead into a cylindrical valve-casing, (indicated at h,) which casing has also connected with it an exhaust-port H and supplyconduit 1). The valve working in the casing is indicated at '1: and is an oscillating valve secured on a spindle, (indicated'at 1?.)

Referring next to the construction shown in Fig. 3, it will be noticed that the sliding delivery and admission valves (indicated at D and D) are actuated through rocker-arms, which, in case of the admission-valves, are indicated at D D and are attached to rockershafts, (indicated at D D from the ends of which, outside of the pump-chamber, extend lever-arms D attached to the valve-actuating rods, (indicated at D said rods having at their ends slots, (indicated at (1,) in which are supported bearing-blocks for camwheels, (indicated at (1 said bearing-blocks being normally held in the position indicated in Fig. 3 by the action of springs, (shown atM.) Also connected with the bearing-block for the cam-wheel (Z is a pivoted lever (1 drawn outward by the action of a spring M, so as to hold the cam-roller normally in contact with a cam Z, secured on a rotating shaft Z, forming, in effect, a positively-actuated partof the pumpengine.

I have shown in the drawings only one of the cams Z and the parts upon which it directly acts; but it will be understood that the construction of Fig. 3 contemplates two such cams, placed side by side on the shaft Z, and operating under precisely-similar conditions on the two valve-actuating rods 0Z 0Z As shown in Fig. 3, each of the rock-shafts D has also attached to it lever-arms, (indicated at D D which, through connections D essentially similar to the connections D in Fig. 1, operate upon lever-arms D D, secured to rock-shaftsD D which, by leverarms D D engage and actlupon the'deliveryvalves D D.

In the operation of the pump-valves, as shown in Figs. 1 and 4, thepressure fluid is admitted to the valve-actuating cylinders F in the direction to actuate the valve in the desired direction, either to open or close it,

as the case maybe, at or preferably slightly before the time, with relation to the motion chamber with which they connect, and, in

valve-seats.

case of the use of sliding valves, the back bearings for'the valves should be so arranged as to give an appreciable, though very slight, freedom of movement to and away from the In consequence of the construction described itwill be obvious that the delivery-valves, when closed, are held to their seats with a pressure ranging from the full pressure in the main to zero, which corresponds to the point when the pressure in the pump-cylinder becomes equal to that in the main, and it is therefore obvious that the valves will only move when the force exerted by the connected cylinder F is greater than that exerted in the form of frictional resistance to hold the valve to its seat, and there- ;fore, practically, the valves, in the pumps equipped in accordance with my method of i of my pump, thus timed to operate in exact,

actuating them, will only move when the pressures on both sides of the valves are equal, or substantially so, or so nearly equal that the force exerted to holdtthe valve in position is not so great as to endanger the connecting and actuating mechanism or other parts subject to injurious strain. It will also be obvious that, when the valve-actuatingconnections are properly constructed and timed for normal operation with relation to the movements of the plunger, and when the pump is working properly and with a full supply of Water in the cylinders, the valves synchronism with the plunger, will work precisely as though positively actuated by moving parts of the engine, but that where these conditions do not exist, and especially Where the not infrequent occurrence of a certain amount of air in-the pump-cylinders exists, then the'valves will remain stationary beyond the period of their normally timed operation and during the period in which the resistance to their operation would be excessive and dangerous, and will only move when the pressures upon the opposite sides of the valve are balanced, or so nearly balanced as may be determined upon. Thus all danger of breaking or injuring the structure is avoided and perfect and smooth operation insured.

In the construction illustrated in Fig. 3 my method of operation is embodied in a structure utilizing springs instead of cylinders actuated through pressure fluid, motion being imparted to the valves by means of the positively-actuated cam Z and the cam-roller (1 which is held against the cam by the action of the spring M and which transmits the thrust of the cam to the valve-actuating rod D and through it to the valves, through the springs M. It will beobvious that in this construction, and by properly regulating the power of the springs, the conditions which bring about unusual resistance to the movement of the valves will permit the valves to remain stationary, notwithstanding the movements of the cam, the thrust of the cam under such conditions being taken up by the spring M, while, on the other hand, motion in the other direction is entirely a result of the pull exerted by the spring M.

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

1. The method of actuating sliding laterally-moving valves in pumps acting upon liquids, which consists in subjecting them to a yielding lateral pressure to open them, said pressure being applied in advance of the proper time of movement of the valve and being insufficient in amount to overcome the frictional resistance developed by the valve on its seat by the pressure tending to keep it shut, but suflicient to energetically open the valve when the pressures on its inner and outer faces are in equilibrium.

2. The method of actuating pump-valves in pumps acting upon liquids, which consists in holding them to their seats by the pressure of the liquid upon which the pump is acting, subjecting them to a yielding pressure in a direction to open them at or slightly before the point in the stroke of the pump-plunger at which they should normally open, said pressure being insuflicient to move the valves against the full pressure exerted to hold them to their seats and regulated to actuate the valves only when the liquid-pressure is balanced to a determined amount.

GUSTAV B. PETSOHE.

Witnesses:

CHAS. F. Mvnns, D. STEWART.

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