US1727517A - Hydraulic valve - Google Patents

Description

Sept. 10, 1929. l. F. MOODY HYDRAULIC VALVE 2 Sheets-Sheet Filed Dec. 30. 1925 noauto@ Sept. 10, 1929. L. F. MOODY HYDRAULIC VALVE Filed Dec. so. 1925 2 sheets-sheet 2 lNVE//NTOR a-n 2'/ BY M Jf//ffv/ W ATTORNEYS Patented Sept. 10, 1929.

UNITED STATES PATENT OFFICE.

HYDRAULIC VALVE.

Application filed December 30, 1925. Serial No. 78,422.

This invention relates to valve mechanisms, and more particularly an improved arrangement of valve parts and means for operating the same. i

It is an object of my invention to provide' a valve involving features which permit the valve to be of minimum outside diameter and reduced size of structure, and consequently of economical cost to manufacture.

1o lt is a further object to provide such features that an improved method of valve operation and control may be had. Still another .object of my invention is to provide an improved arrangement between ahollow plunger valve and improved piston and cylinder elements for operating and controlling` the plunger valve. A further object is to provide improved means for controlling the plunger valve in either direction of movement. A

more specific object is to provide improved means tor preventing quick closure of the valve on approaching its seat, thereby avoiding water hammer. A further specific object is to control the plunger valve operation by regulating dischargeof Huid from a space having a substantially leak-proof piston. Another object in this regard is to provide improved means for securely regulating the discharging fluid.

3o (Ether objects ot' my invention will appear from the following description of the accompanying drawings, in which Fig. 1 is a longitudinal sectional view of the valve mechanism;

Fig. 2 is a modified form of the valve mechanism.

In the illustrative embodiment of my invention, I have shown an outer housing 1 interposed between up and downstream pipes 2 and 3. A combined chaniber-orming and plunger guide member 4 disposed within ythe housing 1 slidably supports a plunger valve 5 by a rearwardly extendiner annular portion 6. A plunger valve seat formed in the front end of the housing 1 is engaged by the plunger nosepiece 5L which is removably secured to the portion 6. A removable point 5b permits removal of a piston rod nut 9a. A piston 8 connected to the plunger valve by a rod 9 is disposed within a cylinder 107 which is a part of the member 4. The front end of the cylinder is closed by a head 11 through which the rod 9 passes while the rear cylinder' end has substantially free communication as by passages 12 with the hollow plungerfchamber A. A small counter-bore 13 is )rovided at the front end of the cylinder. T ie member 4 is provided with a removable cylindrical end 4 to permit rearward removal of 60 piston 8 besides other advantages. The )iston 8 may be provided with suitable packing,

or usual types of snap rings to etect as nearly a leak-proof-piston as possible.

To controlt ie plunger a passage 111 com- 65 municates at one end with a port 15 which is spaced trom the cylinder head 11 and has communication with the counter-bore 13 while the other end of said passage is adapted to communicate with the passage 16 70 formed in the four-way valve 17. The passage 16 Acommunicates with the upstream pipe 2 as by passage 18. A pipe 19 communicates at one end with the rear end of cylinder 10 and chamber A while the other 75 end of said pipe communicates with a passage 20 formed in valve 17. A drain pipe 21 is adapted to communicate at one end with the passage 2O while the other end may communicate with any suitable source of low pressure such as the atmosphere or with the downstream pipe 3. It desired a closure valve may be disposed in line 2l.

To drain the cylinder 10, chamber A, and housing 1, there is provided valve controlled 8 drain pipes .24, 25 and 26 communicating respectively therewith and having communication with a common drain pipe 27. This drainage system does not enter into the normal operation of my device.

In operation of this form of my device, to maintain the plunger valve in or move the same toward open positionl` the valve 17 will. be set as shown, in which case line pressure from pipe 2 will be transmitted to the front end of cylinder 10, while the chamber A which includes the rear end of cylinder 10 will have communication with a lower source of pressure, such as the atmosphere or downstream pipe 3. To close the plunger 100 valve, valve 17 will be rotated through 900 to place the front cylinder end in communication with the low pressure source and to place the chamber A' in communication with a high pressure source, such as the pipe line 2. lll/hen the valve approaches the seat 7, the piston 8 will overrun the port 1,5, as shown in dotted lines, after which any fluid discharged from the cylinder will be by way of the restricted passage formed by the counter-.bore 13, thereby positively retarding plunger movement and preventing the same from slamming. lf desired to stop the plunger in mid-position, the valve 17 may be turned through thereby preventing the discharge or admission of fluid to the front end of cylinder 10, and due to the piston and cylinder having substantially leak-proof fit the plunger will be held stationary.

ln the modilied form shown in Fig. 2, the housing 30 encloses a combined chamberforining and plunger guide 3l, which slidably supports a plunger valve 32 as by an annular portion 33. A piston rod 3a secured at its rear end to the member 3l carries a stationary piston 35 which is disposed within a. cylinder 36 carried by and forming' a part of the annular portion 33. -The trout end of cylinder 36 Ais open to chamber A while the rear end is closed by head 37, through which the rod 34 extends, To control plunger movement, a passage 38 formed in rod 3l communicates at one end with radial ports 39 adjacent an .annular reduced portion 40 While the other end of the passage 38 communicates with a pipe ill. A :tour-way valve 42 has a passage 43 adapted to communicate with the pipe Lll, and with a drain pipe 44, which can be connected to the atmosphere or downstream pipe. The chamber A consisting of the hollow portion of the plunger and the front open end of cylinder 36 is adapted tohave communication with a pipe 48 through valve passage 4S). 'llhe plunger is provided with a removable nosepiece 50 which engages a seat 5l. El. point 52 is removably secured to piece 5l) to permit forward removal ot piston 35, aside from other advantages.

l/-alve controlled drainage pipes 5l and are adapted to have communication respectively with the rear cylinder end.'

chamber A', and housing 30.

The operation of this form of my invention is substantially the same as in the other form except that the cylinder 3G moves with the plunger 32, and when the latter approaches closing position the cylinder head 37 will overrun the radial ports 39, thereby retarding plunger movement by causing discharge of fluid from the cylinder through the restricted annular passage 40.

rllhe two forms disclosed have certain common characteristics, Vsuch as the provision of a hollow plunger, and piston and cylinder elements, so arranged as to provide only two chambers. Also means are provided for positively controlling plunger movement at one end of the plunger stroke, and the plungers may be positively controlled throughout their operation by regulating the discharge of fluid from a single space having a substantially tightly fitting piston.

Among the advantages ot' this valve may be mentioned the fact that in closing the full pressure in the upstream pipe may be admitted to the ent-ire inside surface of the downstream end of the plunger which will result in a force suilicient to close the valve even against the 'reaction of the water when freely discharging` under full head, as in case of a rupture of the downstream conduit below the valve. At the same time the plunger motion in closing may be eitectually controlled or stopped by throttling or shutting oli' the discharge of fluid from a tightly packed cylinder thus insuring that the entrapped, incompressible fluid will automatically adjust its pressure to whatever value is necessary to hold the plunger, rather than by depending solely upon the reduction of the operating pressure which is tending tomove the plunger toward closed position, or by attempting to equalize the pressures acting on the face of the plunger. ln providing a chamber in which fluid can be entrapped for this purpose of control, reliance is not placed on the use of small clearances around the outside of the plunger itself, since these clearances must in practice be made liberal from practical considerations, but as explained this chamber is provided by an internal cylinder of reduced diameter adapted to form a close lit with a piston carried by a piston rod.

l claim l. A valve mechanism comprising inner and outer casing spaced to form a smooth annular liuid passageway, a plunger having telescopic relation4 with said inner casing to form an internal fluid chamber, a cylinder carried by, but spaced inwardly from said plunger, a piston disposed within said cylinder and a piston rod connecting said piston and said inner casing` said cylinder having its upstream end closed while its downstream end is open to said internal chamber.

2. The combination as set forth in claim l further characterized by having the forward end of the plunger entirely closed.

3. A valve mechanism comprising cooperative casing and plunger members having an operating chamber associated therewith, piston and cylinder elements spaced from but operatively connected to said plunger for controlling the same, a piston rod connecting said piston and one or" said members,

communication with said operating chamber,

thereby to form only two fluid chambers, and means within said cylinder for cushioning movement of said plunger near one end of its stroke including a passage within said rod. A

4L. A valve mechanism comprising a plunger having -a closed forward end, piston and cylinder elements for controlling the same, a piston rod, means including a passage eX- tending through said rod whereby fluid may substantially freely flow from one end of said cylinder, and means whereby fluid flow from the other end of said cylinder is adapted to be exhausted.

5. A valve mechanism comprising cooperating casing and plunger members forming a chamber, piston and cylinder elements for controlling said plunger, means whereby liuid may substantially freely flow between the downstream end of said cylinder and said chamber, and means including a groove formed in one of said elements whereby fluid iiow from the other end of said cylinder is automatically restricted upon predetermined relative movement between the piston and cylinder elements.

6. A valve mechanism comprising cooperating casing and plunger members forming a chamber, piston and cylinder elements for controlling said plunger, means whereby fluid may substantially freely iiow between the downstream end of said cylinder and said chamber, and means whereby fluid flow from the other end of said cylinder is automatically restricted upon predetermined relative movement between the piston and cylinder elements, said restriction means including a port adapted to be substantially covered by the piston and a restricted passage which is operative after port covering.

7. A valve mechanism comprising a plunger having an inner pressure receiving surface, means forming a chamber bounded by said surface, piston and cylinder elements for controlling said plunger, said cylinder being spaced from and operatively connected to said plunger, a piston rod, means for controlling the admission and discharge of operating fluid to and from both said chamber and said cylinder, and a passage in said rod for controlling Huid to one end of said cylinder.

8. A valve mechanism comprising a plunger having an inn'er pressure receiving surface, means forming a chamber bounded by said surface, piston and cylinder elements for controlling said plunger, said cylinder being spaced from and operatively connected to said plunger, a piston rod, means for simultaneously controlling the admission and discharge of operating fluid to and from both said chamber and said cylinder, and a passage in said rod for controlling Huid to one end of said cylinder.

9. A valve mechanism comprising a plunger, piston and cylinder elements for controlcovcrin g LEWIS FERRY MODY..

lll)

MEY.

clam 4, strke @ai a@ wam@ @hmm be @ad wia mam @i

Images