US2626635A - Valve construction - Google Patents

Description

Jan. 27, 1953 A. ECKSTEIN 2,626,635

VALVE CONS-TRUCTION Filed Aug. 12, 1949 5 Sheets-Sheet 1' To BURNER -Q Inventor arnalql Eckstein Jan. 27, 1953 A. ECKSTEIN VALVE CONSTRUCTION Filed Aug. 12, 1949 3 Sheets-Sheet 2 Im/enior arnoid ckstein Patented Jan. 2 7, .1953

UNITED STATES PATENT OFFICE Arnold Ec'ksitein; McHenryl, 111., assignoionce Engineering Company, Chicago, 111., a cor ora:

tion of Illinois ApplicationAugust 12, 1949, Serial No. 109,941 25 Claims. (01'. 137 610) This invention relates. to a valve adapted for use in means for supplying oil to a burner by means of a pump.

More particularly, the present invention has to do with a valve for controllingoil in such a Way that a portionof the-oil is delivered to the burner and a portion returnedto a'supply tank.

Ravnsbeck patent, No. 2,103,299; issued December 28, 1937, discloses a-valve for use in connection with oil burners; the present invention constitutes an improvement over the invention disclosed in that patent.

An object of the invention is the provision of a modulating valve for regulating the quantity of oil delivered'to the burner and the quantity returned to the supply tank, in accordance with the load on the burner.-

Another object is the provision of a modulating valve having means for adjusting and controlling the ports to the supply tank and burner, in which adjustments may be readily and easily made in the field.

Still another object is the provision of a valve embodying a modulating action, whereby throttling action characteristic of most previous types of valves is eliminated.

Another object is theprovision of a modulating valve of the character referred to, and aspring return damper motor, in which the damper motor is operable to decrease the flow of oil to the oil burner, so that the burner starts on low fire, and

, after the burner starts, the opening tothe burner is increased.

A further object is the provision of a valve of the character referredto, having-means for varying the size of the return :port to the supply tank, for adjusting and controlling the discharge pressure of the pump to a satisfactory level.

A still further object isthe provision of a valve of the character referred to, havingmeans for controlling both the return port to the supply tank and the burner supplyport, forcontrolling the capacity of the valve to: accommodate the particular size burner with which itis I used. 4

Another object is the provisionof a modulating valve having a novel arrangement of elements and operating parts for'carryingo'ut the objects stated above.

With these and other objects in view, my invention consists in the cnstruction,- arrangement and combination of the-various partsof my device whereby the objects contemplated a-re a-t- ,tained, as hereinafter-more fully set forth,

pointed out in my claims and'illustrated in the accompanying drawings, wherein:

Figure 1- is a diagrammatic" view of a system embodying the modulating valve of the present invention; Y

Figure 2 is an enlarged plan view of the valve;

Figure 3-is an enlarged perspective cut-away view of the valve;-

Figure 4 is a vertical longitudinal sectional view of the valve;

Figure 5 is a sectional of Figure 4; I

Figure 6 is a viewsimila-r to Figure 5, showing certain parts in different positions;

Figure 'Iis a view similar to a portion of Figure i showing certain parts indifferent positions;

Figure Sis aview taken online 8-8 of Fige an Figures 9 and 10' are perspective views of certain of'the operating parts of the valve.

Referring in detail-to the drawings, Figure 1 illustrates diagrammatically a -s-ystem' embodying the modulating valve ofthepresent invention and the system i introduced at this point to illustrate'the'general type of valve-and the use to which it is tobeput.

The modulating valve constituting the present invention isshown in its entirety at l2 and is included in a system which includes a supply tank 14* fromwhi ch leads'a pipe line iiito a constant capacity pump [8' driven by a motor 2%. The pump deliversthe oil from'the supply tank 14* through the pipe line 22" to the valve :2 in which-the oil'is divided into streams, one being delivered'through the pipe line '24 to the burner as indicated, and the other being delivered through the-pipeline ZG back to the supply tank 14*. The details of 'the v'alve proper'will now be described as illustrated in the subsequent figures of the drawing-s:

The valve 2' includes a-valve housing 28 which may be in the form'of a casting having a central were indicated in'it's'entirety at 39, having an enlarged portion ilt'" opening out of" the housing and a reduced portion 3 4 between which is a shoulder 36; thelpor'ti'on 32 may also be termed a distributing chamber. Leading from the reduced portion 34 is' a sman diameter bore 31 having an annular recess 38. Outwardly of the recess 38 is a cavity; formed by a-tubular portion fI h e' cavity 45) is ofgreater diameter than the bore 3 'l for purposewhich is to be explained later. The outer end of the tubular portion has -apart cut away forming a cut-back portion 44 extending partially around the periphery thereof, and shoulders 48.

view taken on line 5-5 Leading upwardly from the reduced portion 34 of the central bore is a passage 53 which communicates with a laterally extending port 52 which will be termed an inlet port, and similarly leading downwardly from the reduced portion 34 is another passage 54 communicating with a port 56 which is also an inlet port.

Leading upwardly from the chamber 32 is a passage 58 having a vertical component and communicating with a transverse passage 53 opening out on one side of the valve body in a port 62 and on the other side in a port 64. The ports 62 and. 64 are herein termed return ports. Leading downwardly from the chamber 32 is another vertical passage 66 terminating in a port 66 which is herein termed an outlet port, or burner supply port. Opening outwardly from the upper end or the passage 50 is another port It for the insertion therein of a pressure indicator. The various ports just described are formed by tubular portions having interior threads for the insertion therein of pipe lines etc. as is well understood in the valve art.

Leading from the passage 53 is a horizontal longitudinal passage I2 having a larger portion I4 forming a shoulder I6, the larger portion opening out of the end of the valve in a threaded segments 18.

The foregoing description covers the valve body and the following description has to do with the operating parts contained in the valve.

A shaft 86 is journalled in the reduced portion 36 of the bore of the valve body and is surrounded by a resilient ring 82 of rubber or other material for sealing that point against outward flow of oil from the valve. Surrounding the shaft 80 and disposed in the cavity 46 is a compression spring 84 which is biased between a pair of washers 86 one of which abuts the inner end of the cavity 46 and the other of which is held in place by means of a washer or ring 36 which in turn is secured to the shaft 66 by means of a set screw 90 having a threaded shank 92 inserted through a radial hole in the ring 86 and threaded into a tapped recess in the shaft. The spring 84 biases against the outer washer 66 and thereby the ring 88 and biases the shaft toward the left. The head of the set screw 90 is received in the cut-back portion 44 of the tubular element 42 and is adapted alternately to engage the shoulders 48 on rotation of the shaft.

Fixed to the outer end of the shaft Bilis a block 34 secured by means of a set screw 36 which engages a flat portion of the shaft. Extending from the block 34 is a modulating rod 98 which is also secured in position by means of a set screw I66 threaded into a tapped opening in the block.

The inner end of the shaft 86 has a reduced portion I02 which extends into the chamber 32 Fixed in the chamber 32, as by a press fit, is a ring I84 (Figures 4 and 9) cup-shape in effect, having a radially extending portion I66 which is abutted against the shoulder 36, and an axially extending flange I38 which engages the wall of the chamber 32. I08 is provided with cut-back portions H and H2 forming extensions H4 and H6 the latter of which has considerably greater axial length than the former. When the ring or member I04 is in position in the chamber 32 the flange I63 thereof extends partially into the projection of the outlet port 68 while it does not extend into the projection of the passage 58 (leading to the return ports). However, the ring I84 is so po- The axially extending flange sitioned that the short extension H4 is disposed adjacent the bottom while the long extension I I6 is disposed adjacent the top of the valve and extends into the circumferential projection of the passage 58.

Forming the counterpart and cooperating with the ring I04 is a cylindrical or cup-shape member H8 rotatably mounted in the chamber 32, the elements I64 and H8 being disposed with their open sides facing each other. The element H3 has a cylindrical portion I26, engaging the wall of the chamber 32, a radial portion I22 and a reduced tubular portion I24, the outer end of the latter being interiorly threaded, and having exterior flattened faces I25. The element H8 is secured in place by means of a ring I26 fitted over the tubular portion I24 and having a projection I28 extending into the chamber 32, the projection being formed with an annular recess I35 in which is disposed a resilient ring I32 for sealing this point of the valve against outflow of oil from within the valve. The ring I26 is secured in place by means of screws I34 inserted through holes in the ring and threaded into tapped holes in the valve body. The outer end of the ring I26 may be of reduced dimension, and exteriorly threaded as indicated at I35.

Returning attention to the element H8, the cylindrical portion I20thereof is formed with cut-back portions I38 and I40 between which are extensions I42 and I44. It will be noted in this case that the portion I46 is of lesser axial dimension than the portion I38 while the extensions I 42 and I 44 are of the same length with respect to each other.

The elements I64 and H3 are so disposed that the extensions thereon are intermeshed and arranged in such a way that the extensions on one of the elements are fitted between the extensions on the other element, and each extension engages the respective cut-back portion. It will be noted also that each cut-back portion is of greater circumferential extent than the extension therein to permit relative rotation of the two elements.

As stated above the extension H6 extends into the circumferential projection of the outlet port or passage 58 and similarly the extension I42 on the element H6 lies in the circumferential projection of the outlet port 58, or in other Words the extensions H6 and I42 are co-extensive in axial dimension.

The numeral I46 indicates a control element which is provided with a hub I48 fitted on the reduced portion I66 of the shaft and secured thereon by means of a pin I53. Extending from the hub I48 is a transverse plate I52 having a plurality of circumferentially arranged holes I54, and extending from the periphery of the plate I 52 is an axial flange I56 engaging the inner surface of the axial flange I68. The extended edge of the flange I56, as indicated at I58, lies in a plane which is vdisposed'at 'an angle to the perpendicular to the axisof the chamber and shaft. The relationship is best shown in Figures 4, 7 and 9. The portion of the flange I56 having the greatest axial dimension is greater than the axial dimension of the flange I08, while the portion of the flange I56 of least axial extent is substantially the same as the axial dimension of the flange I08.

An additional control element is indicated at I69 having a shank portion I62 fitted in and extending outwardly beyond the tubular portion I24, the outer extremity'being threaded as indicated at I64 and threaded in the interiorly threaded part of the. tubularv portion I24. Secured to the outer end or theshank I62lis a knurled knob I 66 provided with a setv screw 1 68 which. is-adapted toengage. afiatportion I69- on the shank. In.- wardlyof thethreaded-portion- I64- is an annular cavity- I in which is aresilientrin I12f'orseal- ,ing this point against the outflow of oilfrom the valve. Extending from. the shank portion I62 is a radial plate I14 having an axial flange I16 which is of uniform axial dimension throughout its circumference. The. plate I14isprovid'ed with aport-or hole I18.

The. numeral I86 indicates. a safety. release mechanism and-includesa rodI82 having. an enially slidable in thesleeve IQIL. The outer end of the rod I82 and sleeve I90: may beprovided with screwdriver slots The sleeve. I90 extends out of the bore in thevalve housing and a-lock nut I92 secures the sleeve in place after it has been turned toadjusted position. An interiorly threaded cap IE4. is threaded over the sleeve I90-andhas a portion enclosing the lock nut I92.

It will be understood that the inlet ports 52 and 56 are to; be alternately-used, that is, when one is in-use the other is plugged, the purpose being for accommodating di-iierent desired piping arrangements. Th same is trueof the return ports 62 and 64. As the-valve is connectedsin the system in-Figure 1 the pipe 22 is threaded into the inlet port 52 and thebottominlet-port 5'6-isplugged. Thepipe 26' is threaded into the return-port 64 and the alternate return port 62 is plugged by means of a screwplug. I96; A pressure gauge I98 is threaded in; the port 10 for determining the pressure within the valve.

Lhe system: in Figure ;1 illustrates a means for automatically controlling the valve and includes a vertical arm 200 connected-- to theswinging end of the modulating rod-68'. A controldevioeillustrated diagrammatically at 2021s provided with an operating lever; arm; 204 which i connected with the vertical link 200. The link 200 is. inserted through a hole ina member 206 which is fixedly mounted in stationary position and acompressiorr spring 208 is biasedbetween the member 206- and the lever arm:204=.. The operation of the control device 202 and. its. efiectr on the; valve will be referred tolater.

Opera-tion There are three-difierentr phases or ways-of operating the valve. One isv to con-trolIcy-simultaneously opening and closing .theoutlet'port and return port totherebyiadjust the. effective size of the, valve to fit the particular. size of burner. with which itis used. 7

The second'is. to adjust. the size of the: return port only, so. that the. discharge-pressure of the pumpcan be ad'iustedlt'o and; maintained at a satisfactory level.

The third isfltolvariably control" or adjust the sizeof" the outlet or supply port to theburner. It i's this means that is employed for directly controlling the-flow ofoil'to the: burner for regulating it as to'highf low, on=ofifor modulating.

Asstated above; the pump" I8 is a constant ca.-

flow ofoilto the valve from thepump is of course mega-3t 6 constant. The oil enters through port 62l(or 5'6), and into the bore 3.4, and from there through holesv I 54- into the distributingchambe'r 32; It is desired to maintain the pressure within the valve fairly constant so that the now of the oil to the valve can be controlled more readily. In order to maintain the desiredpressure in the valve, the arrangement is such that more oil ispumped than necessary for theburner, and a portion of the oil is returned to the supply tank, andthe pressure can be more readily controlled.

Certain pressures are desired so that the desired flow of oil can be maintained in spite of obstructions in the pipe lines. r

The adjustment to be made for sizing. the valve to fit the, particular installation is made in connection with the elements II8 and I04. .A wrench isapplied to the fiat faces I25 of the tubular element I24 for rotating the-element I-I 8. Figure 3 illustrates the-element II8 inthe position wherein both the outlet andreturn ports-are wide open. The extension I42 is-separated from the extension I I6 whereby the oil from the chamber 32 can flow most freely through the passage 58 and outlet port 64. This relationship is also shown in Figure-5 which shows section cutting through both the extensions I42 and I I6. At the same time the extension I44 is separated from the extension II4 providing a spacefor the oil to flow from the chamber 32 downwardly through the outlet port 68. Toclose oft the outlet and return ports, the tubular member I24 is rotated clockwise as viewed from the end of the axis nearest the observer in Figure 3. This rotation moves the extension- I42toward the extension I I6 and likewise the extension I44'toward the extension I14. It is obvious thatthe member II8 can be rotated onlya slight or greater extent, as desired, to close ofi the outlet and. return ports the desired degree. By thusclosing ofi the outlet and return ports to the desired degree, the capacity of the valve is regulated to accommodate the particular size of burner with which it is to be used.

The next adjustment is inconnectionwith the return port only. The element I60 ca-n be moved bodily axially in the chamber. 32 by rotation of the knurled knob I66. It ispreferred that the threads I64 are left hand threads so. that the port opening is enlarged as theknob is turned clockwise. The member I60 can be backed up against the flat portion I22 in which position the axial flange I16 is entirely within the flange I20 and within that portiondetermined by the cutback portion I46 so that the-flange I16 doesnot project to obstruct the flow of oil through the return port 58. The port I18 permitsthe oilto flow behind the element I60 and to flow therefrom, to permit ease in actuation thereof.

When it is desired to reduce the return port 53, the element. I'60' is1 threaded or moved into the projection ofthe outlet port or moved to the left from the position shown in Figure 4, toward the position shown inFigure 7. The member I60 progressively projects farther: intothe outlet: or return port 58 and thereby progressively obstructs. the flow of oil through that port. The reduced portion I02 of the shaft-B H-actsasa stop for limiting the movement of the element I60 to itsfully advanced. position. The member I60 it will be noted is a cup shaped. member and is freely rotatable within the member II8 whereby the axial flanges of the two members are in engagementwith one another.

The member I'4'6'whi'ch is also cup shaped and is so arranged on the shaft 86 that when the modulating rod 98 is in raised position the outlet port 68 is in fully open position. This is brought about by the fact that the portion of the flange I56 which is shortest axially is disposed at the bottom and therefore the portion of greatest length is disposed at the top and a part of it is projected into the outlet port or return port 58. When the element I is retracted to full open position, the element I46 exerts the least eifect on the return port 58. When the modulating rod 98 is moved to lowered position, the outlet port is fully closed because the portion of the flange I56 which is of greatest axial extent is disposed over the outlet port as shown in dotted lines in Figure 7. The axial extent of this portion of the flange is of the proper length that it fully closes the outlet port. The element I60 is moved for the purpose of adjusting the discharge pressure of the pump to a satisfactory level. This member closes or opens only the return port and by reason of that fact the discharge pressure of the pump, and the pressure reflected in the valve, can be regulated. Such pressure can be detected by the gauge I98.

As the member I46 is rotated it will be noted that the outlet port 66 is not abruptly opened or closed, but is only progressively so because of the inclination of the marginal edge of the flange I56. This permits an effective modulating effect as distinguished from an abrupt on-off control. The element I46 therefore is suitably adapted to automatic control.

For the purpose of automatic control reference is directed to Figure 1 in which the control device 202 may be any of various types depending on the use to which the burner is put, such as pressure responsive control, temperature responsive control, aquastat, etc. Assume that the burner is used to heat a steam boiler. The pressure in the steam boiler is transmitted to the control 252 and as the pressure builds up and approaches the desired limit, it actuates the lever arm 204 to force the link 260 and thereby the modulating arm 98 downwardly. This rotates the member Hi6 from the position shown in Figure? in full lines toward the position shown in dotted lines in the same figure. The build up of steam pressure is of course gradual and the lowering of the modulating arm 98 is accordingly gradual, so that a truly modulating effect is accomplished in reducing the outlet port to the burner. The fire of the burner is reduced and eventually the steam pressure is also reduced or balanced, and when it is reduced to the desired limit, the opposite movement of the modulating arm 98 is brought about by the compression spring 208.

When the member I60 is in its fully advanced position as shown in Figure '7, the member I46 is effective for fully closing either the outlet port or supply port alternately. These. ports can also be gradually or partially closed as explained above.

The valve can also be used in a high-low arrangement for starting the burner on low fire. The modulating rod 98 can be moved to lowered position so that the outlet port 63 is nearly closed. It is usually desirable to light the burner on low fire to prevent flash backs and other undesirable effects which might occur if an excessive amount of oil were delivered to the burner before the burner was lighted. After the burner is lighted, greater quantities of oil can be delivered thereto almost immediately andthe burner will consume all of the oil delivered. The arrangement for 015- erating the modulating rod to close the outlet port 68 for starting the burner on low fire may be of any desired character such as a damper motor arranged to operate only after the fire has been started. Such an arrangement does not constitute a part of the present invention and any desired arrangement may be used. Such an arrangement may also be used in conjunction with the type of control illustrated in Figure 1 and described above.

The compression spring 84 acts to bias the shaft to the left to the position in which the member I46 engages the ring I04 and thereby the shaft and all of the elements connected thereto are retained in proper position. The set screw is adapted to engage alternately the shoulders 48 to limit the rotation of the shaft 80.

The relief valve indicated generally at I80 operates as a safety measure. If any of the pipe lines should become clogged, such as the lines 24 and 26, and particularly the line 24 to the burner, excessive pressure would be built up with danger of damaging the valve. However, in that case the plunger I82 is forced out of seating position and the oil returns through the port 12 and return port 64.

One of the chief advantages of the invention will now be apparent and that is that the valve can be set or adjusted in the field to accommodate the particular size burner. The capacity of any valve is determined to a great extent in the factory but there are always many factors which affect the burner orvalve in the field. This can be taken care of by the simple expedient of rotating the tubular element I24 the desired extent. After the burner is in operation the adjustment can be made to suit the particular accidental characteristics of the burner and the operating conditions.

All adjustments made by means of the members II8 and I60 are made with the modulating rod 98 in raised position or in other words with the member I46 in position for opening the outlet port. After those adjustments are made then the actuation or operation of the member I46 will become properly effective.

Another advantage of the present invention is that all throttling action as it is generally known is eliminated. In contrast therewith the present valve is fully modulating.

While I have herein shown and described a preferred form of my invention, manifestly it is susceptible of modification and rearrangement of the parts without departing from the spirit and scope thereof. I do not, therefore, wish to be understood as limiting my invention to the precise form herein disclosed, except as I may be so limited by the appended claims.

I claim as my invention:

1. In a valve, a valve body having a cylindrical chamber, an inlet port, an outlet port and a return port, said outlet and return ports opening through the wall of said chamber, and a pair of cylindrical members in said chamber, one of said cylindrical members being rotatable in said chamber, said cylindrical members having axially extending, interengaging extensions, whereby, upon rotation of said rotatable cylindrical member, the extensions on the respective cylindrical members are moved relatively toward and from each other and effective for closing and opening said outlet and return ports simultaneously.

2. In a. valve, a. valve body having a. cylindrical chamber, an inlet port, an outlet port and areturn port, said outlet and return ports opening through the wall of said chamber, and a pair of cylindrical cup-shape members in said chamber having axial flanges and disposed with their open sides facing each other, the axial flange of each cup-shape member having cutback portions and extensions, the extensions of each cup-shape member being fitted in the cutback portions of the other, each cut-back portion being of greater peripheral extent than the extension fitted therein, one of said cup-shape members being rotatable, whereby the extensions thereon move toward and from the extensions on the other cup-shape member, the extensions on the respective cup-shape members being thereby effective for progrssively closing and opening said outlet and return ports simultaneously.

3. In a valve, a valve body having a cylindrical chamber, an inlet port, an outlet port and a return port, said outl% and return, ports opening through the wall of said chamber, and a pair of cylindrical cup-shape members in said chamher having axial flanges and disposed with their open sides facing each other, the axial flange of each cup-shape member having cut-back portions and extensions, the extensions of each cup-shape member being fitted in and engaging the cutback portions of the other, each cut-back portion being of greater peripheral extent than the extension fitted therein, one of said cup-shape members being rotatable, whereby the extensions thereonmovejtowardand from the extensions on the other cup-shape member, the extensions on the respective cup-shape members being thereby efiective for progressively closing and opening said outlet and return ports simultaneously, the cut-back portions on one of said cup-shape members being of difierent axial lengths relatively to one another, whereby said outlet and return ports are opened to different extents relatively to one another.

4. In a valve of the character disclosed, a valve body having a cylindrical chamber, an inlet port, an outlet port and a return port, annular cylindrical means rotatably mounted in said chamber and engaging the wall thereof, said cylindrical means being operable for closing and variably opening said outlet and return ports, a first blocking member rotatably mounted within said cylindrical chamber, a second blocking member axially movable within said cylindrical chamber, said second member being adapted to be axially advanced to partially close one of said ports, and said first member being rotatable to positions for alternately closing one of said outlet and return ports when said second member is in fully ad-' vanced position.

.5. In a valve, a valve body having a distributing chamber, an inlet port, an outlet port, and a return port, said outlet port and return port opening through the wall of the distributing chamber, a first pair of members in said distributing chamber each having extensions thereon extending into recesses between extensions on the other member, said extensions being adapted, upon movement of said extensions relatively toward and from each other, to efiectuate variable partial blocking of the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and the return port unblocked, anda second pair of members in said chamber adapted to cooperate with each other to variably block theunblocked portion of one of said, ports.

6. A device as set forthiin claim 5 wherein one of said second pair of members is adapted to variably block the other of said ports.

'7. A device as set forth in claim 5 wherein one of said second pair of members is rotatable with respect to the second member, and said second member being bodily movable toward and away from said first member.

8. In a valve, a valve body having a cylindrical distributing chamber, an inlet port, an outlet port, and a return port, said outlet and return ports opening through the cylindrical wall oi said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and return port unblocked, a second pair of members in said chamber adapted to cooperate with each other t variably block the unblocked portion of one of said ports, and one of said second pair of members adapted to variably block the unblocked portion of the other of said ports.

9. In a valve, a valve body having a cylindrical distributing chamber, an inlet port, an outlet port, and a return port, said outlet and return ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and the return port unblocked, and a first blocking member normally positioned to block a part of the unblocked portion of the return port and adapted to be rotated to a position to fully block the outlet port.

10. In a valve, a valve body having a cylindrical distributing chamber, an inlet port, an outlet port, and a return port, said outlet and return ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and return port unblocked, a first blocking member normally positioned to block a part of the unblocked portion of the return port and-adapted to be rotated to a position to fully block the outlet port, and a second blocking member movable to a position where it is adapted to cooperate with said first blocking member to fully block the return port.

11. In a valve, a valve body having a cylindrical distributing chamber, an inlet port, an outlet port, and a return port, said outlet and return ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and return port unblocked, a second pair of cylindrical blocking members concentrically positioned within said first pair of cylindrical members and adapted to cooperate witheach other to variably block the unblocked portion of one of said ports, and one of said second pair of mem- 11 bers adapted to variably block the unblocked portion of the other of said ports.

12. In a valve, a valve body having a cylindrical distributing chamber, an inlet port, an outlet port, and a return port, said outlet and return ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and return port unblocked, a second pair of cylindrical blOCkiIlg members concentrically positioned within said first pair of cylindrical members the first of said second pair of cylindrical blocking members being normally positioned to block a part of the unblocked portion of the re turn port and adapted to be rotated to a position to fully block the outlet port, and the second of said second pair of cylindrical blocking members being axially movable with respect to said first cylindrical blocking member to a position where it is adapted to cooperate with said first blocking member to fully block the return port.

13. In a valve, a valve body having a cylindrical distributing chamber, an outlet port, and a return port, said outlet and return ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and return port unblocked, a second pair of blocking members in said chamber adapted to variably block unblocked portions of said ports, and inlet means for introducing fiuid into the space between said second pair of blocking members.

14. In a valve, a valve body having a cylindrical distributing chamber, an outlet port, and a return port, said outlet and return ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and return port unblocked, a second pair of members in said chamber adapted to variably block unblocked portions of said ports, and inlet means in one of said blocking members for introducing fiuid into said cylindrical distributing chamber.

15. In a valve, a valve body having a cylindrical distributing chamber, an outlet port, and a return port, said outlet and return ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and return port unblocked, and a second pair of cylindrical members in said chamber adapted to variably block unblocked portions of said ports, one of said second pair of members being axially movable, inlet means for introducing fluid into the space between said second pair of cylindrical members, and a relief vent in said axially movable member for equalizing the fluid pressure thereon, so as to provide for ease in axial movement thereof.

16. In a valve, a valve body have a. cylindrical distributing chamber, an inlet port, an outlet port, and a return port, said outlet and return ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block the outlet and return ports, said first pair of members adapted to leave a portion of both the outlet port and return port unblocked,,a first blocking member normally positioned to block a part of the unblocked portion of the return port and adapted to be rotated to a position to fully block the outlet port, a shaft secured to said first blocking member and extending out of said valve body, and automatically controlled means connected to said shaft for rotating said first blocking member.

1'7. In a valve, a valve body having a cylindrical distributing chamber, a pair of ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block said ports, said first pair of members adapted to leave a portion of both ports unblocked, a second pair of members in said chamber adapted to cooperate with each other to variably block said unblocked portion of one of said ports, and one of said second pair of members adapted to variably block the unblocked portion of the other of the said ports.

18. In a valve, a valve body having a cylindrical distributing chamber, a pair of ports opening through the cylindrical wall of said chamber, a first pair of cylindrical members in said chamber rotatable with respect to each other, portions of said first pair of cylindrical members cooperating to variably block said ports, said first pair of members adapted to leave a portion of both ports unblocked, a second pair of members in said chamber adapted to variably block unblocked portions of the ports, and a porting means in one of said second pair of members communicating with said cylindrical distributing chamber.

19. In a valve, a valve body having a cylindrical distributing chamber, a pair of ports opening through the cylindrical wall of said chamber, a pair of cylindrical blocking members in said cylindrical distributing chamber, the first of said pair of blocking members being normally positioned to block a part of one port and adapted to be rotated to a position to fully block the second port, and the second of said blocking members being axially movable with respect to said first blocking member to a position where it is adapted to cooperate with said first blocking member to fully block said partially blocked port.

20. A valve as set forth in claim 19 including a stop member extending from one of said blocking members adapted to engage the other blocking member to limit the relative axial movement of said blocking members.

21. A valve as set forth in claim 19 including means for introducing fluids into the space between said pair of blocking members, and a relief vent in said axially movable member for equalizing the fluid pressure thereon, so as to provide for ease in axial movement thereof.

22. A valve as set forth in claim 19 including a shaft secured to said first blocking member and extending out of said valve body, and auto matically controlled means connected to said shaft for rotating said first blocking member.

23, A valve as set forth in claim 19 including inlet means in one of said pair of blocking members for introducing fluid into said distributing chamber.

24. In a valve. a valve body having an elongated distributing chamber therein, a pair of ports opening through the wall of said chamber and having portions thereof displaced from each other along the length of said chamber, a pair of blocking members in said distributing chamber. the first of said blocking members adapted to be positioned to block a portion of the first of said ports and adapted to be rotated to a position to variably block the second port, and the second of said blocking members being longitudinally movable with respect to said first blocking member to variably block the unblocked portion of said first port.

14' 25. A valve as set forth in claim 24 including a stop member extending from one of said blocking members adapted to engage the other blocking member to limit the relative longitudinal 5 movement of said blocking members.

ARNOLD ECKSTEIN.

REFERENCES CITED The following references are of record in the 10 file of this patent:

UNITED STATES PATENTS Number Name Date 742,327 Huye Oct. 2'7, 1903 5 1,099,713 Morris June 9, 1914 1,642,623 Niven Sept. 13, 1927 2,165,096 Frechette July 4, 1939

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