US1000588A - Balanced valve. - Google Patents

Description

G. A. CUMMINGS.

. BALANCED VALVE.

APPLICATION FILED DEC. 28, 1909.

1,000,588, Patented Aug. 15, 1911 Q Inventor? I Clarence fl. kzmmz'nys. witnesses. Q f? 0 r a Attorneys.

V UNITED. srn'rns PATENT m CLARENCE A. CUMMINGS, 0F FRESNO, GALIIEOIEtll'IA BALANCED vALvE.

Specification of Letters Patent. Pat nt d Qug Application filed December 28, 1909; Serial No. 535,243.. t

To all whom it may concern:

Be it known that 1,-CLARENCE A. CUM- times, a 'citiz'eno'f the United States, residsuch a way that, although subjected on one side to a high pressure and on the other side to a comparatively'low'pressure, the'valve will be balanced sothat the force necessary .to adjust the'degree of opening of thefvalve will be relatively small, that is, such a force as could be exerted by a gas or liquidfunder a low pressure. X p

The invention consists in the construc tion and combination of parts to be more fully described hereinafter and I particularly set forth in the claims. j

In the annexed drawing which fully illustrates my invention, Figure 1 is a I longitudinal vertical section through a valve con-- structed according to my invention and through the pressure regulator which isused in connection therewith, certain parts being broken awayand partly shown in elevation. Fig.2 is aplan of the slide or piston which forms the valve gate,-the packing rings being removed. I y

} Referring more particularly to thedrawis in the form, of a cut oil or slide valve having an elongated body 4: provided with a longitudinal bore 5, said bore being closed by removable heads 6 provided with suitable stufiing boxes 7. Through one of the stufling boxes 7 a valve stem 8 extends, and at the opposite end a tail stem or tail rod 9 is provided which is of'the same diameter as the stem '8'. In the bore 5 a slide or piston 10 is mounted which'is ofv cylindrical form fitting closely in the bore as indicated. Near its .ends this piston is'provided with packing rings 11 bfany suitable forin as shown, On its upper side the valve body is'provided withan inlethub'or boss 12fat an inlet pipe j13 "indicated in dotted lines is attached, and this" inlet pipe is sl ppag -(15a carry a-gas or liquid-under a relatively high pressure.

ing,'3 represents the balanced valve which piston and the heads 6.

Thefunder side of the body 4 is formed into an outlet hub l l; having aver.

tical bore or discharge opening 15 andthis hub 14 is mounted upon a suitable base 16 having a duct 17 communicating with the discharge or outlet 15, and also communicating with the partof the apparatus under low pressure;

vOn its upper side the piston or slide 10 provided with an inlet port 18 which ex- 7 tends downwardly into the interior of the," sl de and connects with a short longit-udil nally extending passage 19 in the interior f of the slide,

connects with the port 18 as shown, and'the One end of this passage-"19 other, end connects with an outlet port 20- formed on the under side of-the gate. In, th1s way the ports 18 and 20 areofiset from.

each other. These ports and the. passage 1'9.v connecting them are of the same width meas-v urcd transversely of theslide, as indicated in Fig. 2.

As shown in 1, the length of the port:-

18 is substantially equal to'the width or diameter of the outlet 15, and the port 20, is of less length measured longitudinally ofthe valve. It will be seen that the passage 19 and the ports 18 and-2O forman offset duct passing through the piston, that is, the ports 18 and 20 are not opposite to each other. Furthermore, onvaccount of the dif surface 22 on the under side of thepassage.

This excess of areais very'slight, however,

and its purpose will appear morefully here; inafter. i A

'ference in length of the ports 18 and 20, T the passage 19 presents a surface 21 on, its, upper side which is of less area than the in whichit slides so that'the chambers 23 and 2 1 are formed between the ends of jth e- These chambers 23 and 24: are in communication with the.

outlet 15 through pipe connections 25 ar ranged as shown. The valve stem 8 1s ad I ustably connected at its end with the end of a rack 26 which lis v, "mounted to slide longitudinally on suitable ,guide. posts 27 attached'to a base plate or bracket [28. This rack26 has teeth on its vupper side which mesh with a gear wheel 29 which is mounted o nvi'a horizontal'jpivotpin 30 secured in the; upper end of a post 31, which post is also mounted on" th base plate 28. The gear wheel 29 is provided with radial slots 32 in one of which a regulator stem 33 is adjustably attached by means of a suitable pin 34. This regulator stem 33 extends into the interior of a pressure regulator 35. This pressure regulator 35 has a body 36, enlarged at its outer end to form a chamber 37, said chamber being provided with a diaphragm 38 held in position by a suitable cover 39. It is also provided with a tubular neck 40 of reduced diameter which extends toward the gear wheel, and-through this neck 40 the stem 33 extends inwardly as suggested, the inner end of the stem beingattached to the diaphragm 38 near its center. Near the diaphragm 38 a collar 41 is fixed on the stem .33 and a coiled spring 42 is arranged so that its inner end thrusts against this collar so .as to resist the movement of the diaphragm in the direction of the gear wheel. The outer end of this spring thrusts against a cap 43 which screws on the end of the tubular neck 40 and havlng an enlarged opening 44 through which the stem 33 passes as shown. The regulator body 36 is suitably mounted on an upward extension or arm 45 fOlmlIlg part of the base plate 28.

As shown. the inner face of the cover 39 is formed with a slight-depression or dish 4'6 so that a part of the chamber 37 is cut off to form a pressure chamber 47. The cover is provided witha central opening 48 which communicates with this pressure chamber 47 and at this opening a pipe connection 49 is attached, the other end of which connects with an opening 50 which is in communication withthe duct 17, that is,'it is in communication withthe low pressure side of the system in which the valve is employed.

The mode of operation of the valve and pressure regulator will now be described.

In this connection it should be understood that the pressure regulator is controlled automatically by the pressure existing in the low pressure system, that is, I control the degree of opening of the valve piston 10 by variations of this low pressure. It will be seen that u'pona rise of pressure in the low pressure system the diaphragm 38 will be moved toward the left. This will rotate the gear wheel 29 in a left hand direction moving the rack 26 toward the right.

This will move the piston 10' toward the right and advance the cut-01f edge 51 of the piston toward the right at the outlet 15.

In this way the degree of opening at this point will be reduced. This reduction of the effective port opening at the port 20 will reduce the pressure existing on the low pressure side of the valve. In this way the pres sure regulator and the'valve cooperate. so as to maintain the pressure on the low pressure side of the system at a substantially constant point.

-Attention is called to the enlarged port 18 and this feature is of great importance in securing the balanced effect in the valve 3,

for the reason that it substantially prevents any application of the high pressure gas or liquid to the upper side face of the piston 10. On account of the fact that the surface 22 is slightly in excess of the surface 21 in area,

it follows that the gas or liquid in the passage 19 exerts a slight downward pressure on the piston 10. In other words, with respect to its interior, the valve is slightly unbalanced sothatthere is a slight excess of downwardly exerted force on itsupper side. This excess of pressure or downward force is balanced however, by. the pressure exerted on the,low pressure side, which pressure is applied to the under side of the valve at the point where the cut-0H edge 51 overhangs the outlet 15. In this way I produce a substantially balancedpiston or gate which will require a very small force to'slide it. It will be understood for these reasons that this apparatus will be very sensitive to slight changes in pressure on the low pressure side of the system.

The ends of the piston 10 are of course balanced by the equality in pressure existing in the chambers 23 and 2. and in this connection it should be noted that the areas exposed to pressure through the pipe connections 25 are equal.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is I 1. A balanced valve comprising a body, a gate sliding within said body and provided with a duct passing transversely there through, said duct having a passage ext-ending longitudinally of said gate and having an enlarged opening on the side of said gate disposed toward the high pressure admis: sion point, said gate having a single opening of reduced size with respect to said enlarged opening disposed on the side of said gate to-' ward the low pressure side of said gate, said passage having an area on its upper side exposed to the pressure within said duct tending to press said gate toward the high pressure side of said valve, and also having an area exposed to thehigh pressure and tending to force said gate toward the low pressure side, said gate being arranged to cutoff on the low pressure side, said areasbeing arranged so that the pressure on said gate from the low pressure side substantially balances the pressure on the high pressure side.

2. A balanced valve having a valve body with a high pressure connection on the upper side thereof and a low pressure connection on the" under side thereof, said high 1 of enlarged diameter, a gate sliding in said bod-y having a duct passing transversely therethrough, sa1d duct comprlslng a passage extending longitudinally, having a port on the upper sidecommunicating'with said high pressure connection and having a port on the lower side communicating with said low pressure connection.

3. A balanced valve having a body with a high pressure connection of reduced dimension on the upper side thereof, a low pressure connection of enlarged dimension on the under side thereof, a gate mounted to slide in said body having a longitudinal passage presenting substantially horizontal surfaces of unequal areas, and having a port on its upper side constantly maintaining communication between said passage and said high pressureconnection, said duct having a cut oif port on its under side communieating with said, low pressure connection. I

4. A balanced valve. comprising a body, a gate sliding within saidbody provided with a duct passing transversely therethrough and having a passage extending longitudinally therein, saidv body having a high pressureconnection on one side of said gate and having a low pressureconnection on the opposite side of said gate, said passage having an area on its upper side exposed to the pressure withinsaid duct tending to press said gate toward the high pressure side of said valve and-also having an area exposed to the high pressure and tending to force said gate toward the low pressure side, said piston being arranged to cut oil" on the low pressure side, said areas being arranged. so that the pressure on said gate from the low pressure side substantially bal' ances said gate; said valve body having chambers in the ends thereof beyond said gate and means for maintaining equality of pressure in said chambers. 5: A balanced valve comprising a body,

a gate sliding within said body provided with a duct passing transversely therethrough and having a passage extending longitudinally .therein, said body having a high pressure connection on one side of said gate and having a low yressure connection on the opposlte side of said gate, sald passage havmg an area on its upper slde exposed to the pressure within said duct tend ing to press said gate toward the high pres sure side of said valve-and also having an area exposed to the high pressure and tending to force said gate toward the low pressure side, said piston being arranged to cut' off on the low pressure side, said areas being arranged so that the pressure on said gate from thelow pressure side substantially balances said gate, said valve body having chambers in the end thereof beyond said gate, and means for maintaining said chambers in communication with the same source of pressure to equalize the pressure on th ends of said gate.

6. A balanced valve having a body with a high pressure connection on one side thereof and a low pressure connection on the opposite side thereof, a gate mounted to slide in saidbody, said gate having a passage therethrough opening communicatlon between said high pressure connection and said low-pressure connection and affording means for balancing'the side pressures on said gate, and a pressure. regulator connected with saidlow pressure connection and. having means formoving said' gate.

7. A balanced valve having-a: body with ahigh pressure connection on one sidethereof and a low pressure connection on the other side thereof, a gate sliding in said bodyand having a ductopening communication between said high pressure connection and said low pressure connection affording means-for balancing the side pressures on saidgate, means for balancing the longitudinal pressures at the ends of said gate, and

automatic means for movingsaid 'gate controlled by the pressure existing in said low pressure connection.

In witness that I claim the foregoing I have hereunto subscribed my name this 20th day of December, 1909.

. .CLARENCE A. CUMMI-N GS.

\Vitnesses:

F. D. AMMEN, E. A. STRAUsE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

e EsT AVAlLABLE corv

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