US2920653A

US2920653A - Valve apparatus

Info

Publication number: US2920653A
Application number: US443838A
Authority: US
Inventors: Charles J Wolff
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-07-16
Filing date: 1954-07-16
Publication date: 1960-01-12
Anticipated expiration: 1977-01-12

Description

y Jan. l2, 1960 Filed July 16, 1954 I C. J. WOLFF VALVE APPARATUS f 4 Sheets-Sheet 2 Char/e: d. Wo/ff \5/a INVENTOR.

Jan. 12, 1960 c.'J. woLFF y yVALVE APPARATUS Filed July i6, 1954 4 Sheets-Sheet 3 C /7 ar/e.: d. WQ/ff INVENToR.

A T TORNE YJ' Jan. 12, 1960 l c. J. woLFF 2,920,653

v vALvx-z APPARATUS Filed .my 16, 1954 4 sheets-sheet 4 ATTRNE YJ United States Patent() VALVE APPARATUS Charles I. Wolff, San Antonio, Tex.

Applicationluly 1'6, 1954,.:Sel'lal No. 443,838

18 Claims. (Cl. 13T-625.43)

This invention relates to valves and, more particularly, t a four-way valve in which the flow stream intovand out of aninlet and outlet, respectively, may be switched between first and second connections with the valve in an improved manner. In one of its aspects, this invention relates to such a valve which is especially well suited for switching between operating and defrost positions in a refrigeration cycle. In another of its aspects, this invention relates to a novel sealing means found especially well suited for use in valves of this type.

The conventional four-way valve employs vsprings and is usually of the sleeve valve Vtype in which a plurality of pistons arearranged in axial alignment. This arrangement of the pistons has necessitated the use lof .radial seals, such as O-rings, ,metal bellows, and the like, between the pistons and `their'respective cylinders, which sealing elements along with the springs are .sources of excessive maintenance.

lIn being switched from an operatng'to a defrost position, a mechanical Arefrigeration cycle `is reversed so as to defrost the expansion coil. A vfour-way valve employed for this purpose must therefore be 'effective to switch high pressure nid from the inlet connected with the compressor discharge to the valve connection Vwith the evaporator, which latter connection was, prior to switching, in communication with the outlet to the low pressure side of the compressor. On the other hand, in switching from defrost to operating position, `the valve must switch said high pressure fluid to the valve connection with the condenser which, during the vdefrost cycle, was in communication with the low pressure outlet. To fully appreciate the many advantages which the valve of the present invention enables in this particular operation, it should be appreciated that the defrost portion ofithe cycle is of relatively short duration compared to the operating portion thereof.

- It is an object lof this invention to provide a fourway valve in which the use of tight radial seals is avoided.

Another object is to provide a .four-way valve having avminimum of parts and necessitating lfew close machine tolesances.

Still another object is to provide a valve especially well adapted for switching betweenfoperating and defrost positions of a refrigeration cycle, wherein only one sealing means is employed between the pressure inlet and low pressure outlet of the valve :in the operating position thereof.

Yet another object is to provide a valve especially well suited for use -in 'a .refrigeration cycle to switch between operating or defrosting positions, rwherein a -valve member having less than a uid tight seal is employed between ythe high and low pressure chambers of the valve in the defrost position thereof.

A still `further object is to provide a valve for selectively l`.switching communication of an inlet between each of two connections, inv which the 'valve Amember therefor ismrabl to permit the inlet to be vented simultaneously to both of said connections intermediate said switch- ICC f2 ing, whereby said inlet and connections will tend to approach an intermediate pressure.

A still further object isto provide a valve of the character defined in the foregoingy object, in'which the valve member is adapted for actuation by pressure from the fluid withinfthe inlet linein amanner todelay the switching for a period during suchventing and then positively completemovement `of the valve member to a switched position.

A stillfurther object is to provide a four-way valve for selectively switching .each :of two connections between communication withpa'high pressure inlet and a low pressure outlet,res pectively, wherein the valve member is operable during a substantial; portionzof the switching operation to prevent communication between the high and low pressure chambers of the valve.

VA still further object is to provide a four-way valve for selectively switchingy each o f two connections between communication with a high ,pressure inlet and a low pressure outlet, respectively, Iwherein the valve member therefore is operable .duringiswitching to vent the high pressure inlet simultaneously'to both of said sections but to prevent communication of the ,low pressure outlet with either of the connections for the inlet during a substantial portion of the switching.

A still further `objectis -to `provide :a four-way valve especially well suited forfswitching between operating and defrost positions in avrefri'geration cycle, in which the valve member is=constructed forlactuation by inlet line pressure from the :compressor discharge of the-cycle and control -by :a pilot valve.

A -still further ,object 'is tto fprovie a novel sealing means `which will :create a `:fluid :tight seal with a minimum of load by establishing a line contact between a sealing element and seating members :therefor regardless of the contour of the respective `seating surfaces thereof.

A still vfurther object :is toprovide a sealing element and members for seating "thereon arranged in such Va mannerthat under varying conditions of load and `upon continued use and wear a line contact will be maintained therebetween. A still further object fis to :providesealing means in which a seal element disposed between seating-surfaces offset from and relatively movable with respect to one another is flexible under application of load to provide continuous line contact Ibetween -said'element and said relatively movable seating surfaces.

A still further object iis to provide sealing means in which linecontacts lbetween l-asealing element and seating surfaces onfopposite sides'thereo'f are caused to move radially closer-together under increasing loads to thereby protect said element against yfatigue stress.

It will be obvious to those skilled in the art that although the apparatus -o`f this invention is particularly described for use in switching between operating and defrost positions of 1a refrigeration cycle, and has been lfound especially well suited for that purpose, the scope of this invention is not restrictedito Isuch use, and other applications for such apparatus are contemplated.

In thedrawings, wherein like reference characters are used throughout to designate ylike parts:

Fig. 1 is a vertical Vlongitudinal sectional view of the valve with the switching valve member thereof in the operating position;

Figs. 2 and 3 are partial views of the valve, showing the valve member intermediate operating anddefrost positions;

Fig. 4 is a view similar to Fig. 1, showinglthe valve member in the defrost .position;

Figs. 5A to 8A, inclusive, are diagrammatic views .of the novel sealing Ymeans of this invention, particularly as used in connection with the valve of Figs. 1 to 4,

upon application of light load thereto for effecting a fluid tight seal; and

Figs. B to 8B, inclusive, correspond, respectively, to Figs. 5A to 8A, but with a relatively heavier load applied thereto.

As shown in the above-described drawings, the valve of the present invention comprises a body having a flow passage 11 therein communicating with an inlet and

outlet

12 and 13, respectively, and first and second connections 14 and '15, respectively. When the valve is employed in a mechanical refrigeration cycle, a conduit 16 connecting with the inlet discharges uid under high pressure from the compressor discharge into the ow passage, while a conduit 17 connecting with the outlet receives fluid from the flow passage and conducts it to the suction side of the compressor.

Conduits

18 and 19 may be threaded into the first and

second connections

14 and 15, respectively, for communication with the condenser and evaporator of the refrigeration cycle. A valve member, designated in its entirety by the numeral 20, is selectively movable within the ow passage 11 between an operating or refrigeration position, as shown in Fig. l, and a defrost position, as shown in Fig. 4. In the operating position, uid from the inlet 12 is conducted into the first connection 14 and returned to the valve through the second connection 15, from which it is conducted back to the suction side of the compressor through the outlet 13. In the defrost position, on the other hand, uid from the inlet is conducted into the second connection, returned to the valve through the first connection, and then discharged through the outlet into the compressor.

From the foregoing, it will be understood that a charnber 21 in the ow passage adjacent the inlet is at all times a high pressure chamber and a chamber 22 in the ow passage adjacent the outlet.r is at all times a low pressure chamber. The high pressure chamber may be more particularly located by its disposition between oppositely facing and coaxially arranged

valve seats

23 and 24 on the body 10 within the ow passage and disposed between the inlet 12 and the first and

second connections

14 and 15, respectively. That is, in the operating position (Fig. l) of the lvalve member 20, ow from the inlet into the irst connection is conducted through the valve seat 23, while in the defrost position (Fig. 4), it is from the inlet into the second connection through the valve seat 24.

The valve member 20 includes what may be considered two separate but mutuallycooperable valve members, one of which kswitches ow from the inlet selectively into either the first or second connection, and the other of which serves to communicate the second connection with the outlet 13 in the operating position vof the valve member and the first connection with said outlet in the defrost position thereof. The low pressure chamber 22 may be more particularly `located by its disposition between the last-mentioned valve member and the outlet 13.

Common to both of the valve membersis a piston means 25 having an imperforate pressure responsive end 26 and a sleeve portion 27 extending downwardly therefrom. This common part of the valve members is movable axially of the flow passage, in a manner to be de scribed, to actuate an annular, ring-shaped sealing element 28 which forms a part of the valve member for switching the inlet selectively between the first and second connections. As well, the piston means 25 is cooperable with a sleeve 29 fixed with respect to the valve body and forming a part of the valve member for switching said connectionsv between selective communication with the outlet. More particularly, the sleeve portion 27 of the piston means carries the sealing element 28 in slidable engagement therewith between oppositely facing and coaxially arranged

valve seats

30 and 31 on its periphery as well as between the

valve seats

23 and 24 0n the body, the valve member being arranged for `movement ooncentrically within the body seats.

4 Y In this manner, upon movement of the piston means axially of the flow passage, the sealing element is selectively seated between oppositely facing seats on the body and piston means. As shown in this illustrative embodiment of the invention, the lower seat 31 is an integral portion of the piston means, while the upper seat 30 comprises a ring-shaped portion threadedly secured -to the piston means. Y

In the operating position of Fig. l, the seated sealing element 28 and imperforate piston means end 26 combine to prevent flow from the inlet into the second connection through the bodyvvalve seat 24; and, in the defrost position, the seated sealing element and sleeve portion 27 of the piston means prevent flow from the inlet into the rst connection through the valve seat 23.

Also, the sleeve portion of the piston means is provided with a Vplurality of ports 32 extending radially therethrough which are cooperable, upon movement of the piston means, with radially extending ports 33 through the sleeve 29 and port means in the form of an opening 34 through the upper end thereof to establish ow selectively between the second and lrst connections and the outlet in the operating and defrost positions, respectively. More particularly, the ports 32 in the piston means are alignable with the ports 33 in the sleeve and the opening 34 is covered or closed by the imperforate end 26 in the operating position of Fig. l. On the other hand, the piston means ports are alignable with the sleeve opening 34 and the ports 33 of the sleeve are covered by the sleeve portion 27 of the piston means 25 in the defrost position of Fig. 4

The valve body 10 comprises top and

bottom sections

35 and 36, respectively, bolted or otherwise secured to an intermediate section 37. A sealing gasket 37a may be disposed between adjoining end surfaces of the

sections

35 and 37 adjacent the high pressure chamber 21. As well, the sleeve 29 is provided with an outwardly extending ilange 38 (Fig. 1) about its lower end which is held between

opposite shoulders

39 and 40 on the

body sections

37 and 36, respectively.

Coaxially of the flow passage are oppositely disposed

cylinders

41 and 42 formed in the

body sections

35 and 36, respectively, and a relatively long portion 43 of the ow passage extending between the second connection 15 and the outlet 13. Disposed axially of the ow passage. is an actuator 44 which comprises a valve stem 45, to which the piston means 25 of the valve member 20 is threadedly secured through the imperforate end thereof, and

pistons

46 and 47 secured by

pins

46a and 47a to the opposite ends of the stem.

Tlhe pistons

46 and 47 are slidable within the

cylinders

41 and 42, respectively, while the sleeve portion 27 of the piston means 25 is slidable telescopically within vthe flow passage portion 43 and over the sleeve 29. In this manner, the

pistons

46 and 47 serve as means for moving the valve memberv selectively between operating and defrost positions, downward movement ofthe pistons serv. ing to move the valve member to the operating position and upward movement thereof serving to move said member to the defrost position. Also, as will be explained more fully hereinafter, the non-sealably sliding relation of the sleeve portion 27 of the piston means within the long passage portion 43 serves to prevent any substantial ilow between the inlet and first and second connections and the outlet.

It is contemplated that the

pistons

46 and 47 of the actuator will be actuated by means of pressure fluid through

connections

48 and 49, respectively, from the high pressure side of the compressor discharge connecting with the inlet 12. It is further contemplated that the connection 49 communicating with the piston 47 will be provided with a pilot valve (not shown) for controlling the application of pressure uid thereto, in a manner and' aoaose to note at this stage of the description, however, that the piston 47 is considerablyA larger-than piston 46, such that e vulve member 20 may be moved to the defrost position of Fig. 4 upon opening of the pilot valve. On the edler hand, clearances of a desired size are provided between the piston 47 and cylinder 42 such that the piston is not sealably slidable therewith and closingV of the pilot 'Hive will permit pressure uid to be bled throughthe dearances past the piston as the piston 47 is urged downwardly by the pressure uid from the compressor discharge acting upon the piston 46.

From the foregoing, it can be seen from Fig. l that in the operating position of the valve member 20, a linge sealing means, in the form of seated sealing element 28 and the cooperating valve seats 24 and 30, provides a duid tight seal between the high and low pressure chambers of the valve. As will be more particularly explained hereinafter, this sealing means may comprise a novel arrangement for establishing a uid tight seal'under relatively low pressure by line contacts of the seats with opposite sides of the sealing element. In any case, howover, each of the valve member seats 30 and 31 is movable in a path concentrically with the similarly facing as well as the oppositely facing body valve seat. As a result, in each of the seated positions of the sealing element, the valve member and body valve seats are offset from one another.

As was previously mentioned, the defrost cycle is of reiatively short duration, such that leakage between the high and low pressure cham-bers is not of much importance. However, for the purpose of preventing any substantial leakage, while at the same time avoiding the use o! radial seals, such as O-rings and the like, the passage portion 43 and sleeve portion 27 yare extended for a vlength sumcient to insure that leakage does not exceed an amount found practical. That is, as previously mentioned, the sleeve and passage portions are telescopically slida-ble relative to one another such that although, in the defrost position of Fig. 4, there may be leakage `past the sleeve portion 27 from the chamber 21 into the chamber 22, such leakage is negligible due to the extent of the afore-mentioned sleeve and passage portions. v

Examining now more closely the switching operation, particularly from operating to defrost position of the valve member 20, it will be appreciated that as the pilot valve is opened to admit pressure fluid beneath the piston 47, such piston and the valve member 20 will begin to move upwardly prior to the pressure acting thereon building up the full extent of the pressure within the compressor discharge line, even though full pressure is at all times acting upon the piston 46. This, of course, is due to the fact that the pressure responsive area of piston 47 is much farger than that of piston 46. AIt will be noted further that in moving upwardly, the piston 47 also overcomes a 'email additional downwardly acting pressure against the area eof valve seat 30. As soon, however, as a small. initial movement occurs and seat 30 unseats from the sealelement 28, this latter pressure is released and the I re member moves quicker and more easily under the force of the expanding uid in cylinder 42.

the first part of the valve movement, between the positions of Figs. l and 2, the sealing element 2 8 remains in contact with the valve seat 31 due t0 the high pressure in the chamber 21 afbove the element. `It will be noted, however, that the unseating of seat 30 from the sealing element communicates the high pressure chamber 21 the low pressure side of the valve through the

ports

32 and 33. It might be thought that this would resuit in serious venting of the high pressure line and consequent loss of pressure for moving the valve member further to" its defrost position. However, the sealing elementi 2l is siidably received about the sleeve portieriV 27 and rts 32 in suciently tight relation that no serious g our-s. Further, what little venting that does Mr it this stage is of relatively short duration as, at

approximately the position ofPi'g. 2, the sleeve portio 27 has'moved suicientlyto disali'gn the

ports

32 and 33 and to dispose the ports 32 into alignment with the intperfo'rate section of the sleeve portion extending` between the ports 33 1and opening l34 of the sleeve 29.

This interruption of venting between the high and low pressure sides of the valve continues during a substantiai portion of the upward movement of the valve member, until such time that the ports 32 become aligned with the opening 34 in the sleeve 29 just prior to bhe valve members reaching the position of Fig. 3. This latter position is, in turn, just prior to seating of the sealing elementl 28 between the seats 31 and 23v and full movement of the valve member to defrost position (Fig. 4). Between the positions of Fig. 2 and Fig. 3, of course, the sealing element is lifted by the valve seat 31 from the body valve seat 24.

Again it would appear from the foregoing that serious venting of the high pressure line would occur in the'nal stages of the switching to defrost position. However, as thehigh pressure inlet is first communicated with the low pressure chamber upon uncovering of the opening 34 by the ports 32, there will be a sudden rush of'uid between the seat 23 and sealing element 28 which actually Vdraws the element away from the lifting seat 31 and into engagement with the upper seat 23.y As previously mentioned, the sealing element fits the sleeve portion closely enough to prevent serious venting thereabout and the piston means 25 will continue upwardly to sealably seat the element 28 between

seats

31 and 23, thereby completeing the switching operation to the defrost cycle.

It will be understood from the foregoing that during a substantial portion of the above-described movement of the valve -member 20, the high pressure inlet is vented simultaneously with both the first and second connections 14 .and 15, respectively, such that the chamber 2-1 and the portions of the ow passage adjacent the inlet, as well as said connections, tend to approach an intermediate pressure. This action has the beneficial effect of charging the connection to which the high pressure inlet is to be switched at the expense of bleeding down the connection which lis to be switched to the low lpressure inlet. As a result of this venting, especially in view of a delay in movement of the valve member during vthe switching operation, as will be described hereinafter, less pumping'is required, after switching to the defrost position, `for bringing the second connection 15 up to high pressure, as a result of which the time required for defrost is materially reduced.

Actually, the valve may and preferably is constructed so as to cause a delay in the movement of the valve member 20 during this venting of the first and second connections. Such delay is accomplished by a -proper design of the pressure responsive area of the

pistons

46 and 47, of lthe volume within the

cylinders

41 and 42, and the restrictions to ow through the connections 48' and 49. Since, as previously mentioned, the pressure responsive area of piston v47 is much greater than that of piston 46 and will begin its upward movement responsive to a pressure much less than that which is acting upon piston 46, the former is affected proportionately much less than the latter during the initial stages of the venting prior to the time at which the venting lessens the pressureupon piston 46 communicating with the connection 48. As this latter condition occurs, however, there is a large net upward force exerted to ymove the valve member toits defrost position.

Although the operation ofthe valve-member=in returning from defrost to operating -position is believed yto be apparent from the foregoing, a brief discussion thereof follows. Initially, of course-the pilot valve is closed such that uid from the high pressure inlet vis no longer -admitted to the -p'iston 47. As a result, uid begins to -leak past this piston and, as soon as the pressure on piston I47 -hasbeen reduced suiciently, the net downwrdfOIC Arelatively heavier load (Figs. B to 8B).

will cause the valve member 20 to move downwardly. As in the case of the upward movement of the valve member to defrost position, there is a substantial portion of the switching operation in which venting between the high and low pressure sides is prevented.

Also, of course, there is a delay during the venting of the first and second connections in order to equalize the pressure therebetween as again the piston 47 is not affected thereby to the extent of the piston 46. However, the rate of leakage past the piston 47 is such as to lower the pressure on said piston to permit the valve member to continue its downward movement.

The aforementioned novel Vsealing means is illustrated under a variety of conditions in Figs. 5A to 8A and 5B to 8B, inclusive. In this connection, it should be noted that thev sealing means employed in the valve of Figs. l to 4, and of which sealing element `28 forms a part, is shown only diagrammatically in said figures and may, if desired, assume the more detailed construction of the novel sealing means herein described.

Basically, this novel sealing means comprises a pair of relatively and guidably

movable members

50 and 51 arranged with thesealing element 28 disposed therebetween for establishing a uid tight seal upon movement of said members toward one another and application of a relatively light load to the sealing element. lTo accomplish this purpose, the seating surfaces 50a and 51a of the members are offset from .one another a distance less than the thickness of the sealing element, from one side to the other uponwhich the members seat, and the sealing element is elastic to permit its exure yupon application of load thereto.

Due to the above-mentioned arrangement of the sealing element and seating surfaces, the contact therebetween will, under average loads, be along a line regardless of the contour of said surfaces and thus permit uid tight sealing under relatively light loads. That is, even if the seating surfaces and oppositely disposedsides of the sealing element are, originally and prior to wear from extended usage, parallel to one another, the initial contact under load will be along a line due to the elasticity or flexibility of the sealing element. On the other hand, continued usage of the sealing element and seating surfaces will, instead of impairing the tight seal .therebetween, wear the seating surfaces in a manner to maintain at all times the above-mentioned line contact. That is, the arrangement of the sealing element and the seating surfaces is such that under varying load conditions the line contact is moved whereby the softer of the element and surfaces is worn away to a curved contour which will effect the line contact.

ln the illustrative embodiment of this application, the seating surfaces on the

members

50 and 51 describe enclosed paths, particularly circular, and are movable conccntrically within one another. That is, the outer edge of one seating surface has a path of movement concentrically within that of the inner edge of the other seating surface, such that line contacts established by said 'surfaces with the sealing element are radially offset from one another. A practical application of this sealing means is illustrated by the valve above-described in connection with Figs. l to 4. That is, in such a case, the outer concentric seat 51a of member 51 would corre spond to either

valve seat

23 or 24 and the seat 50a to either

seat

30 or 31. Although the illustrative embodiment of Figs. 5A to 8A and 5B to 8B are shown only diagrammatically, it will be understood that flow through either or both

seating surfaces

50a and 51a may be controlled by the sealing element 28.

Referring now more particularly to the above-noted line contact movement, it can be seen that under each of the conditions illustrated, the sealing element is flexed from a substantial ring shape when underV light load (Figs. 5A to 8A) into a frusto-conical shape under a Of course,

these shapes are merely illustrative of a preferredsembodiment although, in -any case, increasing load will cause the element to tend to turn inside out wherebyfa" given point on one side thereof will be moved outwardly while a given point on the other side thereof will be moved inwardly. During this exure of the sealing element, the line contact between said element and the seating surfaces 50a and 51a moves from the inside out and from the outside in, respectively. Such movement under increasing loads brings thel line contacts radially closer together and provides protection to the sealing element against fatigue stress.

As previously mentioned, the rolling and rubbing action resulting from such movement will wear away 'a portion of the softer of the sealing element and seating surfaces. In the condition illustrated in Figs. 5A and 5B, the sealing element is the softer and thus has been worn froma substantially rectangular cross section to that villustrated in Figs. 5A and 5B wherein each side thereof facing a seating surface is worn to a convex contour.

In the condition villustrated in Figs. 6A and 6B, the

members

50 and 51 are made of the softer material such that whilethe sealing element has retained its rectangular cross section, the

surfaces

50a and 51a are contoured convexly. In the condition illustrated in Figs. 7A and 7B, the surfaces '50a and 51a are of harder material and convexly contoured. As a result, the sealing elementis worn concavely, but to a different radius. On the other hand, the sealing element surfaces are worn convexly by the harder concave seating surfaces of Figs. 8A and 8B. v

The above-described conditions are thought to represent basically all those which may arise and thus to illustrate the manner in which line contact is maintained during continued usage.

Although the above-described embodiments are illustrative of the invention, they are not to constitute a limitation upon the `scope thereof.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations-are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims;

As many possible embodiments may be made of the invention Without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. Y

The invention having been described, what is claimed is:

1. A valve comprising, a body having a flow passage therein, an inlet to said flow passage, first and second connections communicating with said flow passage, substantially oppositely facing and coaxial valve seats on the body within the passage between the inlet and each of said connections, means guidably movable within said passage axially of the valve seats, substantially oppositely facing valve seats on the periphery of the means, the outer edge of the seats on said means having a path of movement eoncentrically within the inner edge of the seats on the body, and a sealing ring carried for longitudinal movement annularly of the 'means between said meansk seats as well as said body valve seats for seating between a valve seat on the body and an oppositely facing seat on the means upon movement of the means in opposite directions axially of the ow passage to selectively prevent flow from the inlet through the body valve seat upon which the sealing ring is seated, said sealing ring being elastic and so formed relative to the seats as to establish line contact with said seats during flexing under load.

2. A four-way valve comprising, a valve body havingV a ow passage therein, an inlet to and outlet from said.v

9 flow passage, first and second connections with said flew passage, and a pair of valve members within said passage, one of said valve members having parts relatively movable between opposite positions for selecti'wly preventing flow from said inlet into each of said HM and second connections and for communicating said inlet Simultaneously with each of said connections intermediate said opposite positions, and the'other of said volvo members having parts relatively movable between opposite positions for selectively communicating said fst connection lwith said outlet when the first-mentioned valve* member parts are in position for preventing ow from the inlet into said first connection and communicathtgsaid second connection with said outlet when the firstientloned valve member parts are in position for preventing flow from the inlet into said second connection, the relative movement of the parts of said other valve member being further operable to prevent communication between leither of said first and second connections and said outlet daring at least a portion of the movement of said parts of the first-mentioned valve member betweenl its opposite positions.

3. A four-way valve of the character defined in claim 2, wherein one of the parts of each of the valve members constitutes a common part.

4. A four-way valve comprising, a valve body having a 110W passage therein, an inlet to and outlet from said ow passage, first and second connections communicating with said flow passage, valve seats on the body within the passage between the inlet land each of said connections, and a valve member within said passage, said valve member including seal means movable to selectively seat upon said valve seats to prevent flow from said inlet .ler'edn'otlgh and to communicate said inlet simultaneously'with each of said connections intermediate said seated positions and slide valve means carrying said seal means for movement between its seated positions and having port means cooperable to selectively communicate-said first connection with said outlet when said seal means is seated upon the valve seat between said inlet and first connection and to communicate said second connection with said outlet when said seal means is seated upon the valve seat between said inlet and said second connection.

5. A valve comprising, a valve body having a ow passage'therein, an inlet to and outlet from said flow passage, rst and second connections communicating withsaid ow passage, valve seats on the body within the passage between t'ne inlet and each of said connections, and a valve member within said passage, said valve member comprislng three relatively movable parts selectively operable in a first position to direct flow from the inlet into the first connection and from the second connection into the outlet and, in a second position, to direct ow from the inlet into the second connection and from the first connection into the outlet, a first of said valve member parts being a sealing element carried by a second part for seating upon the valve seat between the inlet and second connection in said first position and seating upon the valve seat between the inlet and first connection in said second position, said second part and a third part having port means alignable in said first position to communicate said second connection with said outlet and in said second position to communicate said first connection with said outlet.

6. A valve of the character defined in claim 5, one of said second and third parts being provided with an imperforate section alignable with the port means of said other part during a portion of the relative movement between said parts intermediate seating of said sealing element with said valve seats.

7. A valve of the character defined in claim 5, wherein said second and third parts are sleeve-like members and said sealing element is carried annularly of said second part, said valve seats being oppositely facing and coaxial, and said parts being relatively movable with respect to one another in a direction axially of said valve seats.

8. A valve of the character defined in claim 7, said sec- CJI ond part being provided with oppositely facing seats about its periphery, and said sealing element being dis-` posed between said last-mentioned seatsV as well as the body valve seats, whereby, in the 'first and second positions of the valve member, the sealing element is seated between a valve seat on the body andan oppositely facing valve seat on the second valve member part.

9. A valve of the character defined in claim 8, wherein the port means in the second part is disposed between the valve seatsthereon, and the third part is provided with spaced apart port means having an imperforate section therebetween, one of said third part portmeans -beingr alignable with the second part port means in said first position and another of said port means being alignable therewith in said second position, said imperforate section and said second part port means being alignable with one another intermediate said first and second positions.

10. A valve comprising, a valve body having a flow passagel therein, an inlet to and outlet from said flow passage, first and second connections communicating with said flow passage, oppositely facing and coaxial valve seats on the body within the passage between the inlet and each of said connections, the outlet communicating with the inlet and said connections through a portion of said' flow passage extending axially of said valve seats, and a valve member including relatively movable parts disposed within said iiow passage, one of said parts cornprising piston means slidable longitudinally within said axially extending passage portion, and a sealing element carried by said piston means part between the oppositely facing valve seats for movement into seated positions thereon to selectively prevent iiow from the inlet therethrough, each of said valve member parts having port means cooperable with one another upon relative movement therebetween to selectively provide communication through said piston means part between each of said connections and said outlet when the sealing element is seated upon the valve seat between the respective con` nection and the inlet. y

'11. A valve of the character defined in claim l0, wherein the valve member is provided with a stem extending axially of said body valve seats and piston and cylinder instrumentalities at opposite ends thereof for imparting movement to said stem axially of said valve seats,'one of said pistons being non-sealably sldable within its cylinder and having a larger pressure responsive area than its opposite piston.

l2 A valve of the character defined in claim l0, wherein said piston means is non-sealably slidablewithin the axially extending portion of the liow passage.

13. A valve of the character defined in claim l0, wherein the piston means is provided with oppositely facing seats about its periphery and at opposite sides of the sealing element, each seat on the piston means being adapted for movement within the similarly facing valve seat on the body, whereby the sealing element is engaged between oppositely facing seats on the body and piston means in its selectively seated positions.

14. A valve of the character defined in claim 13, wherein said valve member parts include telescopically arranged sleeve portions in which said port means are disposed, the port means in the sleeve portion of the piston means part being disposed between the seats on the periphery of said piston means part.

15. In a valve, a ow conduit having a substantially circular seating Surface about an end thereof, a member having a substantially circular seating surface thereon in oppositely facing and concentrically arranged relation to the conduit seating surface, said conduit and member being movable relative to one another in a path axially of the concentric seating surfaces, the outer edge of said member seating surface having a path of movement within that of the inner edge of the conduit seating surface, and a ring-shaped sealing element disposed between said oppositely facing seating surfaces, the faces of said sealing element and seating surfaces on said member and conduit being so related that, upon relative movement of the conduit and member toward one another, initial line contact of the member seating surface with the sealing element is established radially inwardly of the outer edge of said seating surface and initial line contact of the conduit seating surface therewith is established radially outwardly of the inner edge of said conduit seating surface, said sealing element being formed of an elastic material which permits it to retain its shape as it is llexed from its ring shape into a frusto-conical shape during continued relative movement of said conduit and member toward one another under load whereby the line contact of the member seating surface with theY sealing element is moved radially outwardly of its initial contact therewith and the line contact of the conduit seating surface'with said sealing element is moved radially inwardly of its initial contact therewith.

16. A four-way valve comprising, a valve body having a ow passage therein, an inlet to and outlet from said ow passage, rst and second connections communicating with said ow passage, valve seats on the body within the passage between the inlet and each of said connections, and a valve member within said passage, said valve member including seal means movable to selectively seat upon said valve seats to prevent flow from said Vinlet therethrough and to communicate said inlet simultaneously with each of said connections intermediate said seated positions and relatively movable parts having port means cooperable to selectively communicate said first connection with said outlet when said seal means is seated upon the valve seat between said inlet and first connection and to communicate said second connection with said outlet when said seal means is seated upon the valve seat between said inlet and said second connection, one of said relatively movable parts being provided with an imperforate Section cooperable with the port means of another` part to prevent communication between either of said connections and said outlet during at least a portion of the time in which said seal means is positioned intermediate its seated positions.

17. A four-way valve, comprising a valve body having a ow passage therein, an inlet to and outlet from the flow passage, first and second connections intersecting said ilow passage, valve seats on the body within the passage between the inlet and each of said connections, and a valve member within said ow passage including relatively slidable sleeves having ports therein and an annular sealing member carried by one of said sleeves, said one sleeve being movable between` la first position seating said seal- 12 ing element upon the seat between the inlet and said sec ond connection to direct ow from said inlet into said first connection and aligning a port `therein with a port in the other sleeve for directing flow from the second connection into'the outlet, and a second position seating said sealing element upon the seat between the inlet and said first connection to direct flow from said inlet into said second connection and aligning said port therein with another port in the other sleeve for directing ow from the first connection into the outlet, said ports being aligned intermediate seating of said sealing element to pennit flow between said inlet and said outlet, and means for moving said sleeve between said positions.

18. A four-way valve, comprising a valve body having a ow passage therein, aninlet to and outletr from the flow passage, first and second connections intersectingsaid ow passage, substantially axially aligned and oppositely facing valve seats on the body within the passage between the inlet and each of said connections, a first sleeve extending from the outlet into the passageway substantially coaxally of said body valve seats, a second sleeve closed at one end and slidably received over said first sleeve,'op positely facing valve seats about the periphery of the second sleeve, an annular sealing element carried about the second sleeve intermediate said seats for seating, in one axial position of the second sleeve, between a seat on the second sleeve and the seat on the valve body between the inlet and said first connection, and, in another axial position of the second sleeve, between the other seat on the second sleeve and the seat on the valve body between the inlet and said second connection, said sleeves having ports therein alignable, in said first position of the second sleeve, to communicate said rst connection with said outlet, and, in said second position of the second sleeve to communicate said second connection with said outlet,

and means for moving said sleeve between said positions.

ReferencesCited in the le of this patent UNITED STATES PATENTSl