US3406701A - Two-stage fluid control valve - Google Patents

Description

Oct. 22, 1968 J w, MEULENDYK 3,406,701

TWO-STAGE FLUID CONTROL VALVE Original Filed March 9, 1964 2 Sheets-Sheet 1 r ..u I

INVENTOR JOHN W. MEULENDYK mm-W ATTORNEY Get. 22, 1968 Uriginal Fi lllll rc J. W- MEULENDYK United States Patent M 3,406,701 TWO-STAGE FLUID CONTROL VALVE John W. Meuleudyk, Kalamazoo, Mich., assignor to Pneumo Dynamics Corporation, Cleveland, Ohio, a corporation of Delaware Continuation of application Ser. No. 350,409, Mar. 9, 1964. This application Sept. 13,- 1966, Ser. No. 579,176 12 Claims. (Cl. 137-83) ABSTRACT OF THE DISCLOSURE A fluid control valve having a porting link member pivotally mounted in the valve housing, the porting li 1k member being formed with receiving passages for supplying fluid to chambers at opposite ends of the valve spool, fluid being directed to said receiving passages by fluid transfer means having a ported end portion for receiving fluid from a fluid supply and directing the same to said receiving passages, the porting link member being so pivoted as to provide greater transverse movement at its lower end than at its upper end.

Disclosure This application is a continuation of application Ser. No. 350,409, filed Mar. 9, 1964, and now abandoned.

The present invention relates to flow control valves and more particularly to an improved two-stage fluid control valve.

Two-stage fluid control valves are per se well known in the art, the first stage comprising means for controlling relatively small quantities of fluid flow, and the second stage being controlled by the first stage to permit accurate, controlled supply of relatively large quantities of fluid flow to a power mechanism for operating the same. Present two-stage valves have not proved satisfactory for a number of reasons, a primary one being the limitation on the movement of the second stage element due to its particular operative arrangement with the first stage element, thereby placing a definite limit on the capacity of the valve. Present two-stage valves of the jet pipe type possess a further disadvantage owing to their inherent lack of requisite accuracy at extreme temperature conditions.

A primary object of the present invention is to provide a two-stage fluid control valve wherein means are provided for amplifying the movement of the second stage element relative to the movement of the first stage, such amplification, however, not in any way reducing the accuracy of the valve in response to the control force for actuating the same.

A further object of the present invention is to provide means disposed between the first and second stage elements operatively connected to the latter for accurately maintaining the latter in its adjusted position, such position being accurately proportional to the direction and magnitude of the control force controlling the first stage element.

A further object of the present invention is to provide a two-stage valve capable of highly accurate flow control even at extreme temperature conditions.

A more specific object of the present invention is to provide a two-stage valve wherein the first stage element includes a fluid transfer means defining a relatively short flow path relatively remote from the means for controlling the position of the first stage element whereby neither the control means nor the fluid transfer means is significantly affected by relatively high temperature fluid.

A further object is to provide a two-stage flow control valve that is highly simplified in construction and comprised of few parts thereby to enhance manufacture thereof.

Patented Oct. 22, 1968 These and other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings seeting forth in detail an illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a diagrammatic view of the fluid contro valve of the present invention; and

FIG. 2 is a fragmentary, enlarged view of a portion of the FIG. 1 valve.

Referring now in detail to the drawings, wherein like parts are designated by like reference characters, the valve housing is generally indicated at 10 and a torque motor generally indicated at 12 is mounted in the upper end thereof. The torque motor 12 is conventional and accordingly forms no part of the present invention, comprising an upper pair of permanent magnets 14 and 16 and a lower pair of permanent magnets 18 and 20. In the usual manner, the opposed ends of each pair of magnets are of opposite polarity and are laterally aligned.

A fluid transfer member generally indicated at 22 is also mounted in the upper end of the valve housing and in the form shown comprises an armature 24 mounted intermediate its ends by means of a torque rod 26, the latter being fixed at both ends to the valve housing thereby to create torsion in the same when the transfer member 22 is rotated in either direction by a control force. In the absence of such control force, the torque rod 26 positions the fluid transfer member 22 in its null position illustrated in FIG. 1. It should be understood, and it will become apparent as the description proceeds, thatthe transfer member could be movably mounted by other means, mechanical as well as electrical, e.g., by means effecting reciprocal movement thereof, without impairing its control function.

In the form shown, the armature 24 has associated therewith windings 28 and 30 having terminal ends connected in a well-known manner to an electrical signalproducing means for supplying an electrical control signal thereto. Such signal thereby produces amagnetic flux effective to rotate the armature 24 about the torque rod axis, the direction of rotation and the arc through which the armature 24 rotates being controlled by the direction and magnitude of the control singal, all in a well-known manner.

The enlarged lower end 32 of the fluid transfer member 22 has formed therein a curved fluid passageway 34 the opposite ends of which define an enlarged fluid inlet 36 for receiving fluid under pressure and a relatively reduced discharge orifice 38 through which the fluid is discharged. The enlargement of the inlet 36 permits the fluid transfer member 22 to receive fluid under pressure during all operative positions thereof.

A valve spool generally indicated at 40 is disposed for reciprocation in a generally cylindrical-shaped bore 42 formed in the valve housing 10 relatively adjacent the bottom thereof, such bore including chambers 44 and 46 at opposite ends of the spool. The valve spool 40 is gen erally cylindrical, being provided, however, with a plurality of longitudinally spaced, annular grooves of varying depth which combine with associated grooves formed in the valve housing to control the flow of pressurized fluid delivered to the valve housing through fluid inlet ports 48 and 50. Thus, the valve spool 40 is formed with an annular groove 52 communicating during all positions of the spool with the fluid inlet port 50, the groove 52 being adapted to communicate at certain positions of the spool with an annular groove 54 and control port 56 formed in the housing. The port 56 in turn communicates through fluid line 58 with one end of an external power mechanism indicated in dashed lines at 60. In the position of the valve spool 40 illustrated in FIG. 1, an annular wall 62 prevents the fluid entering the valve at port 50 from communicating with the port 56, and it is only following movement of the valve spool to the right, referring to the FIG. 1 orientation, that the groove 52 of the valve spool will communicate with the port 56 for supplying fluid to the mechanism 60.

Similarly, the valve spool 40 is formed with an annular groove 64 adjacent the opposite end thereof which communicates with the fluid supply port 48 during all positions of the valve spool. An annular groove 66 is formed in the valve housing, an enlarged portion of which communicates with a control port 68 communicating with the opposite end of the mechanism 60 through fluid line 70. An annular wall 72 prevents the pressurized fluid delivered to the fluid inlet port 48 from communicating with the control port 68 during the null position of the valve spool. It will be apparent, however, that movement of the valve spool to the left, again referring to the FIG. 1 orientation thereof, will establish communication between the inlet port 48 and the control port 68 whereby fluid is supplied to the adjacent end of the mechanism 60. The valve spool 40 is further formed with a central groove 74 for returning fluid to a return port 78, the latter being connected by means not shown to a fluid reservoir or like fluid source.

The power mechanism 60 forms no part of the present invention and is intended merely to exemplify one type of device which can be controlled by the valve of the present invention. The power mechanism 60 includes a piston 80 and rod 81, the opposite sides of the piston being subjected to fluid pressure entering the mechanism 60 through the fluid lines 58 and 70 as above described. It will be apparent that the position of the piston 80 within the mechanism 60, and thus the device (not shown) connected to and controlled by the piston rod 81, will vary depending upon the fluid pressure acting on the opposed faces thereof.

A fluid passageway 82 is formed in the valve housing which communicates at one end with the fluid inlet port 50 and at its opposite, enlarged end with a supply passage 84 of a porting link member generally indicated at 86. Similar fluid passages 88 and 90 are formed in the valve housing for delivering proportional amounts of fluid from the porting link member 86 to the chambers 44 and 46, respectively, at the opposite ends of the valve spool 40.

The porting link member 86, which serves to supply fluid to, and receive fluid from, the fluid transfer member 22, is formed with a generally spherical, bulb-like intermediate section 92 mounted in a complemental opening 94 formed in the valve housing. An additional opening or openings (not shown) are formed in the valve housing adjacent the opening 94 to permit excess fluid to be returned to return passage 78. The porting link 86 is mounted for pivotal movement in the housing by means of pivot rod 96. The lower end of the porting link is slightly enlarged as indicated at 98 and is disposed within an opening 100 provided therefor in the valve spool 40, thereby directly linking or connecting the porting link member 86 to the valve spool whereby the position of the latter controls the position of the porting link member.

The bulb-like portion 92 and the upper end 102 of the porting link 86 are formed with a plurality of fluid passageways, including the supply passageway 84 described earlier, which serves to direct fluid to the transfer member 22, and receiving passageways 104 and 106 communicating respectively with previously described fluid passages 88 and and chambers 44 and 46 at opposite ends of the valve spool 40. The receiving passageways 104 and 106 terminate at the upper surface of the porting link member in theform of receiving orifices 108 and 110 disposed generally below the discharge orifice 38 of the transfer member 22. In the, null position of the fluid transfer member 22 and the porting link 86, the discharge orifice 38 is equidistantly spaced from the receiving orifices 108 and 110 whereby the fluid emanating from the discharge orifice 38 is directed substantially equally into the receiving passageways 104 and 106 thereby effecting substantial equal pressure conditions within the chambers 44 and 46, respectively, at opposite ends of the valve spool.

The discharge end of the supply passageway 84 in the porting link is relatively reduced as indicated at 112 to form a discharge orifice disposed generally below the enlarged inlet 36 of the fluid transfer member 22, such arrangement permitting fluid communication therebetween during the controlled movement of both members. By incorporating the fluid supply line 84 for the transfer member in the porting link 86, there is thus eliminated the need for a separate supply means for delivering fluid to the transfer member. It will also be noted that the length of travel of the fluid through the potting link member 86 and the transfer member 22 is relatively short thereby substantially decreasing the adverse effects of extreme temperature conditions on these movable members. The fluid passages 82, 88 and 90 are slightly enlarged at their ends adjacent the porting link whereby such passages are insensitive to movement of the porting link during operation of the valve.

It will be noted that in the form shown the distance between the top of the porting link 86 and the rod 96 is approximately one-fourth the distance fromthe top of the porting link 86 to the center of the enlarged portion 98 at the opposite end thereof. The locating of the pivot axis of the porting link substantially closer to the top of the porting link and the receiving orifices 108 and 110 formed thereat permits a substantially greater movement of the valve spool relative to the receiving orifices. Such amplification of valve spool travel permits accurate, controlled delivery of substantially larger fluid flows to the power mechanism 60. Such mechanical amplification and resulting increase in flow capacity is not at a sacrifice of accuracy, however, since the direction and magnitude of movement of the valve spool is always directly proportional and in response to the control signal Supplied to the torque motor 12.

Regarding now the operation of the control valve, in the null position of the valve components, in the absence of a control signal being applied to the torque motor 12, the discharge orifice 38 of the fluid transfer member 22 is equidistantly spaced from the receiving orifices 108 and 110 whereby fluid delivered to the fluid transfer member 22 from the inlet port 50 and passages 82 and 84 is discharged therefrom through discharge orifice 38 into the porting link receiving orifices 108 and 110 in substantially equal amounts thereby creating substantially equal pressures therein. The fluid is directed from the receiving orifices 108 and 110 into chambers 44 and 46 at opposite ends of the valve spool 40 thereby to create thereat substantially equal pressures which maintain the valve spool in its null position.

When an electrical control signal is supplied to the torque motor 12, the fluid transfer member 22 will rotate about the axis through the torque rod 26, the direction of rotation and the magnitude of the are through which the tube rotates being dependent upon the direction and magnitude of the control signal. Assuming that the control signal supplied to the torque motor 12 is such to produce counterclockwise movement of the transfer member 22 about the torque rod axis, as viewed in FIG. 1, the equidistant spacing of the discharge orifice 38 of the transfer member from the receiving orifices 108 and 110 in the porting link will be interrupted. In the direction of rotation indicated the discharge orifice 38 will direct a greater quantity of fluid to the receiving passage 104 relative to the passage 106, with the pressure in passage 88 correspondingly increasing relative to the pressure in passage 90. The pressure in chamber 44 will thus become greater than the fluid pressure in chamber 46 at the opposite end of the valve spool 40. As a result of such pressure differential, the valve spool 40 will move to the left, again referring to its FIG. 1 orientation, whereupon communication will be established between the fluid inlet port 48 and the control port 68. Fluid will thus be supplied through line 70 to the adjacent face of the piston 80 thereby moving the same to the left within the mechanism 60. Movement of the valve spool 40 to the left also serves to establish communication between the control port 56 and the return port 78 whereby fluid forced from the opposite side of the piston 80 will be directed to the return passage 78 for return to the fluid reservoir or like supply source.

As the valve spool 40 moves to the left as described, the porting link 86 will pivot in a clockwise direction about the pivot rod 96. Movement of the upper portion of the porting link will substantially reestablish equidistant spacing between the discharge orifice 38 of the transfer tube and the receiving orifices 108 and 110 of the porting link. Equal pressures will thus be recreated Within passages 88 and 90 and chambers 44 and 46 thereby to maintain the valve spool 40 in its adjusted position. It will be seen that such adjusted position is directly proportional to the direction and magnitude of the control signal supplied to the torque motor 12. Thus, a greater movement of the transfer member 22 in response to a control signal of greater magnitude will effect proportionally greater movement of the valve spool, with the receiving orifices 108 and 110 also moving through a correspondingly greater arc to reestablish equidistant alignment thereof with the discharge orifice 38 thereby to maintain the valve spool in its adjusted position.

When the electrical signal to the torque motor is cut off or when the control signal is opposite in direction to the initial control signal, the armature '24 will be rotated in the opposite direction, or clockwise as viewed in FIG. 1, thereby directing a proportionally greater quantity of fluid into the receiving orifice 110, thereby resulting in a relatively greater fluid pressure in chamber 46 causing movement of the valve spool 40 to the right. Such move ment will establish fluid communication between the fluid inlet port 50 and the control port 56, with the extent of movement of the valve spool 40 being dependent upon the magnitude of the control signal delivered to the torque motor 12. The fluid supplied to the control port 56 is delivered through line 58 to the adjacent side of the piston 80 thereby moving the same to the light within the mechanism 60. The fluid within the mechanism 60 on the opposite side of the piston 80 is forced through line 70 and control port 68 to return port 78.

The movement of the valve spool 40 to the right will effect counterclockwise movement of the porting link 86 about the pivot rod 96 whereby the receiving orifices 108 and 110 will again become equidistantly spaced from the discharge orifice 38 thereby to supply fluid substantially equally to the receiving orifices 108 and 110. Substantially equal fluid pressures within chambers 44 and 46 will be recreated whereby the valve spool 40 will be maintained in its adjusted position. If the movement of the transfer member was a result of a cut-off of the control signal, the valve components will return to their null positions.

It will be seen that through the described arrangement a control signal of relatively small magnitude can be utilized to control the flow of relatively large quantities of fluid. In the first stage operation, the transfer member 22, moving in response to the control signal, receives a relatively small quantity of fluid under pressure and delivers the same in disproportionate amounts to the receiving orifices 108 and in the porting link 86. The second stage of the valve operation, comprising the valve spool 40, is controlled by such relatively small quantity of fluid delivered to the first stage to control in turn the flow of substantially larger quantities of fluid required for operation of the external power mechanism 60. The quantity of fluid delivered to the mechanism 60 is directly proportional to the magnitude of the control signal delivered to the torque motor. Further, in accordance with the present invention, the valve spool 40 is capable of substantially greater movement than either the transfer member 22 or the receiving orifices 108 and 110 of the porting link due to the pivotal mounting of the latter relatively adjacent its upper end about the pivot rod 96. Such pivotal mounting provides a second stage mechanical amplification that is not possible in devices wherein the travel of the receiving orifices is substantially equal to the travel of the valve spool.

The control valve of the present invention finds further advantage due to the manner of fluid transfer afforded by the use of the fluid transfer and porting link members. The fluid transfer member 22 provides a means whereby the fluid directed thereto and transferred thereby is at all times remote from the mounting thereof, the fluid directed to the transfer member 22 being confined to the curved passageway 34 thereof which is relatively remote from the torque rod 26 and the torque motor 12. The fluid transfer member 22 thus substantially lessens adverse effects on the torque motor which would otherwise result from the extreme temperature fluids to which the valve is often subjected. Moreover, the relatively short path of fluid travel in the porting link and the transfer member sub stantially lessens the effects of the extreme temperature conditions thereon. The problem of extreme fluid temperatures has posed a considerable problem with other types of fluid control valves, particularly those of the jet pipe type wherein fluid is directed through the elongated jet pipe which generally extends between the torque motor poles, thereby subjecting the torque motor as well as the entire length of the pipe to the extreme temperature of the fluid passing therethrough.

Other modes of applying the principles of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A fluid control valve comprising a valve housing, a valve spool mounted in said valve housing adapted to control the flow of fluid to an external mechanism, the opposite ends of said spool defining with portions of said housing a pair of chambers adapted to receive fluid under pressure for controlling the position of said spool, porting link means pivotally mounted in said housing, one end of said porting link means being associated with and movable by said spool, said porting link means being formed with a supply passage and a pair of receiving passages, each of said receiving passages communicating respectively with one of said chambers, fluid transfer means pivotally mounted in said housing, said fluid transfer means including an inlet generally oppositely disposed from one end of said supply passage and a discharge orifice generally oppositely disposed and adapted to be equidistantly spaced from the adjacent ends of said receiving passages, control means for varying the position of said fluid transfer means whereby a proportionally greater amount of fluid may be directed by said discharge orifice into one of said receiving passages relative to the other of said receiving passages thereby creating a fluid pressure differential in said chambers which effects move ment of said spool, such movement in turn effecting pivotal movement of said port-ing link means thereby permitting re-establishment 'of equidistant spacing of said discharge orifice from said receiving passages to maintain said spool in its adjusted position.

2. The combinatiaon of claim 1 wherein said porting link means is pivotally mounted relatively adjacent said fluid transfer means thereby permitting substantially greater movement of said spool relative to said porting link receiving passages.

3. A fluid control valve comprising a valve housing, a valve spool mounted in said valve housing adapted to control the flow of fluid to an external mechanism, the opposite ends of said spool defining With portions of said housing a pair of chambers adapted to receive fluid under pressure for controlling the position of said spool, porting link means pivotally mounted in said housing, the lower end of said porting link means being associated with and movable by said spool, said porting link means being formed with a supply passage and a pair of receiving passages, each of said receiving passages communicating respectively with one of said chambers, fluid transfer means movably mounted in said housing having an end portion adapted to receive fluid from said supply passage and direct the same into said receiving passages, control means for varying the position of said fluid transfer means thereby to supply variable amounts of pressurized fluid to each of said receiving passages and thus to said chambers thereby to control the position of said valve spool.

4. A fluid control valve comprising a valve housing, a valve spool mounted in said valve housing adapted to control the flow of fluid to an external mechanism, the opposite ends of said spool defining with portions of said housing a pair of chambers adapted to receive fluid under pressure for controlling the position of said spool, a porting link member, means for pivotally mounting said porting link in said housing, one end of said porting link means being associated with and movable by said spool, said porting link member further comprising an intermediate, generally spherical portion pivotally mounted in a complemental opening formed in the valve housing, said spherical portion of said porting link comprising supply and receiving passages adapted to communicate respectively with a source of fluid and with said chambers, said fluid supply and receiving passages terminating at the opposite end of said porting link in the form of supply and receiving orifices, respectively, fluid transfer means movably mounted in said housing adapted to receive fluid from said supply orifice and direct the same into said receiving orifices, control means for varying the position of said fluid transfer means thereby to supply variable amounts of pressurized fluid to each of said chambers for controlling the position of said spool.

5. The combination of claim 4 wherein the pivotal mounting of said porting link is relatively adjacent said fluid transfer means thereby permitting substantially greater movement of said spool relative to the movement of said receiving orifices of said porting link.

6. The combination of claim 4 wherein said fluid transfer means is formed with a curved passageway the ends of which define a relatively enlarged inlet for receiving fluid from said supply passage and a relatively reduced discharge orifice for directing fluid into said receiving passages, said curved passageway effecting substantially full reversal of direction of said fluid as it passes therethrough.

7. A fluid control valve comprising a valve housing, a valve spool mounted in said valve housing adapted to control the flow of fluid to an external mechanism, the opposite ends of said spool defining with portions of said housing a pair of chambers adapted to receive fluid under pressure for controlling the position of said spool, a porting link member, said porting link member comprising an intermediate, generally spherical portion pivotally mounted in a complemental opening formed in the valve housing, said spherical portion of said porting link being relatively adjacent one end of said porting link thereby to form relatively long and relatively short link member Y 8 r sections extending therefrom, said relatively long end section being associated with and movable by said spool, said relatively short section and said spherical portion being formed with receiving passages adapted to communicate respectively with said chambers, said receiving passages terminating at one end in the form of receiving orifices and at their opposite ends with fixed passages formed in said valve housing communicating respectively with said chambers, fluid transfer means movably mounted in said housing adapted to receive fluid andto direct the same into said receiving orifices, control means for varying the position of said fluid transfer means thereby to supply variable amounts of pressurized fluid to said receiving orifices and thus to each of said chambers for controlling the position of said spool.

8. A fluid control valve comprising a valve housing, a valve spool mounted in said valve housing adapted to control the flow of fluid to an external mechanism, the opposite ends of said spool defining with portions of said housing a pair of chambers adapted to receive fluid under pressure for controlling the position of said spool, porting link means pivotally mounted in said housing, the lower end of said porting link means being associated with and movable by said spool, said porting link means being formed with a supply passage and a pair of receiving passages, each of said receiving passages communicating respectively with one of said chambers, fluid transfer means movably mounted in said housing having an end portion adapted to receive fluid from said supply passage and direct the same into said receiving passages, said end portion of said fluid transfer means being formed with a curved passageway the ends of which comprise a relatively enlarged inlet adapted to receive fluid from said supply passage and a relatively reduced discharge orifice adapted to deliver fluid to said receiving passages, and control means for varying the position of said fluid transfer means thereby to supply variable amounts of pressurized fluid to each of said receiving passages and thus to said chambers thereby to control the position of said valve spool.

9. The combination of claim 8 wherein the axes of said inlet and said discharge orifice are substantially parallel, said curved passageway thereby effecting substantially full reversal in direction of fluid flowing therethrough, said supply and receiving passages formed in said porting link means being similarly parallel in the portions thereof adjacent the fluid transfer means for respectively directing fluid to said inlet and receiving fluid from said discharge orifice.

10. A fluid control valve comprising a valve housing, a valve spool mounted in said valve housing adapted to control the flow of fluid to an external mechanism, the op posite ends of said spool defining with portions of said housing a pair of chambers adapted to receive fluid under pressure for controlling the position of said spool, a porting link member pivotally mounted in said housing, one end of said porting member being associated with and movable by said spool, said porting member being formed with a pair of receiving passages each of which communicates respectively with one of said chambers at opposite ends of said spool for supplying fluid thereto, fluid supply means formed in said valve housing for supplying fluid to said porting link member, fluid transfer means movably mounted in said housing and interposed between said fluid supply means and said receiving passages in spaced relation thereto, said fluid transfer means having a ported end portion remote from the pivotal mounting of said fluid transfer means, the transfer of fluid through said fluid transfer means being confined to said ported end portion thereof, said ported end portion receiving fluid from said fluid supply means and directing the same into said receiving passages, and control means for varying the position of said fluid transfer means thereby to supply variable amounts of pressurized fluid to each of said receiving passages and thus to said chambers thereby to control the position of said valve spool.

11. The combination of claim 10 wherein said receiving passages extends through only a portion of said porting member, each of said receiving passages communicating respectively With one of said chambers through a fixed fluid passage formed in said valve housing.

12. The combination of claim 10 wherein said fluid transfer means is formed with a curved passageway the ends of which define a relatively enlarged inlet for receiving fluid from said fluid supply mens and a relatively reduced discharge orifice for directing fluid into said receiving passages, said curved passageway eflecting substantially full reversal of direction of said fluid as it References Cited UNITED STATES PATENTS 2,742,022 4/1956 Jacques 13783 X 3,211,182 10/1965 Gyurick 137625.63 X 3,272,077 9/1966 Meulendyk et al. l3783 X ALAN COHAN, Primary Examiner.

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