US3256906A

US3256906A - Bi-directional time delay valve

Info

Publication number: US3256906A
Application number: US256322A
Authority: US
Inventors: Walter D Ludwig
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-02-05
Filing date: 1963-02-05
Publication date: 1966-06-21
Anticipated expiration: 1983-06-21
Also published as: DE1228480B; GB1029624A

Description

June 21, 1966 W. D. LUDWIG 3,256,906

BI-DIRECTIONAL TIME DELAY VALVE Filed Feb. 5, 1963 5 Sheets-Sheet l INVENTOR. WALTER D. LUDWIG 1 41 WyM ATTOR N EYS June 21, 1966 w. D. LUDWIG [BL-DIRECTIONAL TIME DELAY VALVE 5 Sheets-Sheet 2 Filed Feb.

m 0W D mu V L m D R m L A W ATTORNEYS June 21, 1966 w. D. LUDWIG BI-DIRECTIONAL TIME DELAY VALVE 5 Sheets-Sheet 5 Filed Feb.

ATTORNEYS United States Patent 0 3,256,906 BI-DIRECTIONAL TIME DELAY VALVE Walter D. Ludwig, 3865 Lincoln Drive, Bloomfield Township, Oakland County, Mich.

Filed Feb. 5, 1963, Ser. No. 256,322 15 Claims. (Cl. 137-493) This invention relates generally to time delay apparatuses for controlling the flow of pressurized fluid in a fluid circuit, and more particularly to a time delay air apparatus which is adapted to function independent of any valve and which can be used at any point in a pressurized fluid circuit exclusive of an operating valve.

The prior art time delay air units incorporate the time delay structure as an integral part of an operating valve and the prior art delay air units can only be employed with the specific incorporated operating valve structure. This is a disadvantage because in order to get a time delay function in a pressurized fluid circuit, it is necessary to purchase a certain and often undesired attached operating valve. A further disadvantage of the prior art time delay units is that they require disassembly' and adjustment when they are changed from a timing-in to a timing-out operating position, and the same requirements must be met when reversing the aforementioned connection. Another disadvantage of the, prior art time delay air units is that the time delay period is governed or controlled by the particular type of valve with which it is combined, whereby the versatility of the time delay unit is restricted- Still another disadvantage of the existing time delay air units is that they are constructed with dead end passageways which normally collect contaminates carried by the pressurized fluid. A further disadvantage of prior art time delay units is that the timing sequence tends to vary greatly as the system pressure fluctuates.

Accordingly, it is an important object of the present invention to provide a time delay unit which is adapted to be used in any pressurized fluid circuit, exclusive of an operating valve, and which can be adjusted to various desired time delay periods.

It is another object of the present invention to provide a novel and improved time delay unit for use in pressurized fluid circuits and which may be connected in such circuits between a directional flow control valve and a fluid cylinder or valve to provide timing-in operations, or timing-out operations wherein the timing-out cycle is not started until the pressure is released at the primary source, and which can be further employed in a pressurized fluid circuit for timing fluid flow in only one direction, and providing free flow of the fluid in the other direction.

It is still another object of the present invention to provide a novel and improved time delay unit for use in pressurized fluid circuits which is constructed so as to purge water and dirt which may be carried along with the fluid.

' It is a further object of the present invention to provide a novel and improved time delay unit which may be used in any pressurized fluid circuit but which is especial ly adapted for use in pressurized air circuits, and which includes a body having a pair of ports for fluid entrance and exit operations, a passageway connecting said ports,

a flow valve in said passageway for controlling fluid flow therethrough, accumulator means for opening said flow valve, means for normallymaintaining said flow valve in a closed position when said accumulator means is inoperative, pressurized fluid metering means for admitting a metered flow of said fluid into said accumulator means for operating the same in predetermined timed cycles for timing the opening and closing of said flow valve to provide a delayed flow of pressurized fluid between the ports when the fluid moves through the passageway in one direction, and a free flow of pressurized fluid when the fluid moves through the passageway in the opposite direction.

It is still a further object of the present invention to provide a novel and improved time delay unit that is not as susceptible to variations in timing sequence, due to fluctuations in system pressures, by maintaining a constant relationship between the system pressure and the pressure required to open the flow valve, and by utilizing the same system pressure which acts to oppose the opening of the flow valve as the source of metered pressure for the accumulator means for opening the flow valve so that a variation in the system pressure produces a compensating variation in the rate of metered flow to the accumulator means.

Other objects, features and advantages of this invention will be apparent from the following detailed description and appended claims, reference being had to the accompanying drawings forming a part of the specification.

In the drawings: a

FIG. I is a full size, side elevational view of a time delay apparatus made in accordance with the principles of the present invention;

FIG. 2 is aleft end, elevational view of the structure illustrated in FIG. 1;

FIG. 3 is a top plan view of the structure illustrated in FIG. 1; I

FIG. 4 is a bottom plan view of the structure illustrated in FIG. 1;

FIG. 5 is an enlarged, central elevational sectional view of the structure illustrated in FIG. 2, taken along the line 5-5 thereof and looking'in the direction of the arrows;

FIG. 6 is a fragmentary, elevational sectional view,

illustrated in FIG. 6, taken along the line 77 thereof and looking in the direction of the arrows;

FIG. 8 is a fragmentary, horizontal sectional view of the structure illustrated in FIG. 6, taken along the line 8-8 thereof and looking in the direction of the arrows;

FIG. 9 is a horizontal sectional view of the structure illustrated in FIG. 1, taken along the line 9-9 thereof and looking in the direction of the arrows; and, FIG. 10 is a horizontal sectional view of the structure illustrated in FIG. 1, taken along the line 1010 thereof and looking in the direction of the arrows.

The time delay apparatus of the present invention is especially adapted to be used in pressurized air circuits. The time delay apparatus of the present invention is adapted to be operatively connected between a device to be controlled, as for example, an air cylinder, and a conventional directional flow control valve for the purpose of timing-in and timing-out operations. The time delay apparatus of the present invention may also be used for other purposes as, for'example, in an air line leading to a directional flow control valve to time the operation of that valve for timing the air-in and air-out periods of air flowing to the directional flow control valve.

Referring now to the drawings, the numeral 10 generally indicates the time delay unit body which is preferably made from aluminum or any other suitable material. As shown in FIGS. 5, 6 and 7, the body 10 is provided on the right end thereof with a control fluid chamber 11 and on the left end thereof with a free flow fluid chamber 12. The chamber 11 is provided with the entrance port 13 which is circular and threaded for the reception of the pipe bushing 15. The chamber 12 is provided with the exit port 14 which is also circular and threaded for the reception of the pipe bushing 16. The

chamber 11 extends inwardly over the chamber 12. The.

Patented June 21, 1966 inner ends of the chambers 11 and 12 are substantially rectangular in vertical cross-section. As shown in FIG. 5, the inner overlapping ends of the chambers 11, and 12 are interconnected by the valve bore 17. As shown in FIG. 5, the

ports

13 and 14 are aligned. The valve bore 17 is vertically disposed at an angle perpendicular to the longitudinally extended chambers 11 and 12. The chambers 11 and 12 and the valve bore 17 form a pressurized fluid passageway through the body 10.

The time delay unit includes a metering means comprising the metering tube generally indicated by the numeral 18. The tube 18 is vertically disposed and extends through the valve bore 17. Slidably mounted on the metering tube 18 is a check valve or flow valve generally indicated by the numeral 19 for blocking fluid flow through the valve bore 17. The check valve 19 is provided with a cylindrical body on the upper end of which is formed a sealing ring seat 20 by means of the vertically spaced apart, outwardly extended

shoulders

21 and 22. A moulded sealing ring 23 is operatively mounted in the seat 20 and engages the valve bore 17 when the valve 19 is in the closed position as shown in FIG. 5. The sealing ring 23 may be made from any suitable sealing ring material as, for example, a suitable rubber or the like. As shown in FIG. 5, a conical compression spring 24 is mounted around the upper end of the metering tube 18 and is adapted to move the valve 19 to the closed position. The upper end of the spring 24 engages the upper wall of the chamber 11 and the lower end of the spring 24 engages the shoulder 22 of the valve 19.

As shown in FIGS. 5, 9 and 10, the lower end of the metering tube 18 extends into an accumulator chamber which is formed in the lower end of the time delay unit. The accumulator chamber includes the central circular portion 25 and the

end portions

26 and 27 which are formed in the lower end of the body 10. The accumulator chamber further includes a plurality of communicating chamber portions in the accumulator cover, generally indicated by the numeral 28, and which is substantially rectangularly shaped. The accumulator cover 28 may be made from any suitable material as, for example, die cast zinc. Formed in the accumulator cover are the

accumulator chamber portions

29 and 30 which are interconnected by means of the central chamber portion 31. The

cover chamber portions

29 and 30 are disposed under the

chamber portions

26 and 27, respectively, formed in the body 10. The accumulator chamber portion 25 functions as an accumulator piston [cylinder as more fully described hereinafter. The cover chamber portion 31 is disposed under the body chamber portion 25 and communicates with the same. The accumulator cover 28 is provided with the inwardly

extended projections

32 and 33 which are best seen in FIGS. 7 and 9. The

projections

32 and 33 have an upper flat surface which is even or level with the upper surface of the cover. The

projections

32 and 33 extend inwardly under the accumulator chamber portion 25. The accmulator cover 28 is detachably connected to the body 10 by any suitable means as, for example, by a plurality of machine screws 35. The cover 28 is provided with a pair of integral upwardly extended locating dowels 36 and 37 which are adapted to be seated in the

holes

38 and 39, respectively, formed on the lower side of the body 10. A suitable gasket 34 is interposed between the cover 28 and the body 10.

As shown in FIGS. and 7, the upper end of the accumulator chamber portion 25 is vented to the atmosphere by means of the passageway 40. The accumulator chamber is vented to the atmosphere by a second passageway which includes the vertical bore 41 in the body which has the lower end thereof communicating with the cover chamber portion 29. Pressed into the lower end of the bore 41 is a tube 42 which extends to within approximately & of 'an inch of the lower end of the accumulator chamber portion 29. As shown in FIG. 5, the upper end of the vent bore 41 communicates with the reduced vertical bore 43 which in turn communicates with the horizontal bore 44. The bore communicates with the enlarged exhaust piston chamber 45 which is open at the outer end thereof to the control fluid chamber 11. The inner end of the piston chamber 45 is vented to the atmospheric by means of the drilled passageway 46.- Slidably mounted in the piston chamber 45 is the exhaust piston 47 which is provided with a' suitable O-ring sealing means 48. Mounted on the inner end of the piston 47 is a poppet sealing member 49 for normally enclosing the outer end of the passage 44 when fluid pressure is admitted to the chamber 11. The cross sectional area of the passage 44 is about of the cross sectional area of the piston 47 to permit the piston 47 to be held in the closed position against the end of the passage 44 when the fluid pressure in the chamber '11 fluctuates or drops as compared to the pressure in the accumulator chamber. For example, if the pressure in the inletline dropped to about 20 pounds per square inch and the pressure in the accumulator chamber was pounds per square inch, the exhaust piston 47 would maintain the closed position to hold the flow valve 19 in the open position, as more fully described hereinafter. The poppet seal 49 and piston 47 function to provide the poppet valve or exhaust valve for controlling the exhaust of the fluid under pressure from the accumulator chamber.

As shown in FIG. 5, a differential accumulator piston.

generally indicated by the numeral 50 is slidably mounted in the vertically disposed accumulator chamber portion or piston cylinder 25. The piston 50 is provided with the O-ring 51 on the lower end thereof. The upper end of the piston 50 is reduced as indicated by the numeral 52 and is slidably mounted through the bore 53 formed in the chamber wall on the lower side of the free flow fluid chamber 12. A suitable O-ring sealing means 54 is mounted around the bore 53 for engagement with the piston upper end 52. The piston 5t engages the lower end of the flow valve 19 for moving this valve upwardly to the open position as shown in FIG. 6.

As shown in FIGS. 5, 6 and 7, the differential accumulator piston 50 is provided with an axially formed bore 55 in which is slidably mounted the lower end of the metering tube 18. A suitable O-ring sealing means 56 is mounted in the upper end of the piston 50 for engagement with the metering tube 18. The metering tube 18 is provided with a suitable O-ring sealing means 57 for engagement with the tubular body of the flow valve 19. The lower end of the metering tube 18 is provided with the cross slot 58 in which is slidably received the upwardly extended tongue 59 which is integrally formed on the cover 28. The metering tube 18 is provided with the axially extended bore 69a which forms the exit part of the metering passageway and which communicates at the lower end thereof with the cross slot 58 and at the upper end thereof with the enlarged metering valve chamber 60.

The body 10 is providedv with the upwardly extended projection 61 on the upper end thereof and formed in the projection 61 is an inwardly extended cylindrical recess 62. As shown in FIGS. 5, 6 and 7, the upper end of the metering tube 18 extends through the control fluid chamber 11 and through the bore 63 formed in the upper wall of the chamber 11 and into the recess 62. A suitable O- ring sealing means 64 is mounted in the wall of the bore 63 for engagement with the metering tube 18. Fluid under pressure is adapted to be admitted to the metering valve chamber 60 in the metering tube 18 from the chamber 11 by the following described structure.

The inner end of the recess 62 is-connected to the chamber 11 by means of the inlet part of the metering passageway formed by the passage 65, the inlet valve chamber 66, the passage 67 and the enlarged circular bore 68. The upper end of the passage 65 communicates with the inner end of the recess 62. The lower end of the passage 65 communicates with the inlet valve chamber 66 in which is slidably mounted the inlet poppet valve piston 70. Mounted on the inner end of the piston 70 is the poppet seal 72 which is adapted to block off the passage 67 during free flow of fluid through the time delay apparatus. The inlet valve piston 70 is provided with a suitable O-ring sealing means 71. A conventional sintered bronze filter 69 is mounted in the enlarged bore 68. The

pistons

47 and 70 are similarly constructed.

As shown in FIGS. 5, 7 and 8, a vertically disposed, substantially V-shaped slot 73 is formed on the upper end of the metering tube 18 for communicating the metering valve chamber 60 with the inner end of the cylindrical recess 62. The operative portion or effective opening of the slot 73 is controlled by the rotatable metering valve 74 which is slidably mounted in the upper end of the valve chamber 60. A suitable sealing means 75 is mounted around the lower end of the valve 74. The upper end of the metering valve 74 is splined, as indicated by the numeral 76, for fixed seating engagement in the recess 77 formed in the rotatable metering valve control knob 78. The outer surface of the control or adjustment knob 78 is knurled.

As shown in FIGS. 5, 6 and 7, the metering valve control knob 78 is provided with a circular flange 79 on the lower end thereof which is rotatably seated in the recess 62. A suitable O-ring sealing means 80 is carried in the outer periphery of the flange 79 for engagement with the wall of the recess 62. A conventional snap ring 81 is mounted in a groove in the wall of the recess 62 and engages the upper side of the control knob flange 79 for maintaining the knob in the recess 62. A conventional wave washer 82 is mounted in the inner end of the recess 62 below the control knob flange 79 and normally urges the control knob flange 79 upwardly against the snap ring 81. circular recess 83 formed on the lower side of the knob flange 79. The wave washer 82 maintains the control knob 78 in spaced apart relationship from the inner end of the recess 62 to permit pressurized fluid to flow under the control knob 78 and through the slot 73 into the meter ing valve chamber 68. To facilitate the flow of pressurized fluid into the slot 73, the control knob 78 is provided with the axial recess 84, on the inner end. thereof, which communicates with the wave washer recess 83. The upper end of the metering tube 18 is externally threaded and is threadably mounted in the inwardly extended thread axial bore 85.

The period of time delay provided by the apparatus of the present invention under any given inlet line pressure is set by adjusting the metering tube 18 upwardly or downwardly relative to the metering valve 74 to increase or decrease the delay period, as desired. FIG. 5 shows the metering tube 18 disposed at one end of its travel so as to provide a maximum opening of the metering slot 73. FIG. 6 shows the metering tube 18 adjusted upwardly whereby the rotatable metering valve 74 has been moved downwardly into the valve chamber 60 to further enclose the slot 73 and increase the delay period. The smaller effective entrance area of the slot 73 reduces the rate of flow of pressurized fluid into the valve chamber 60. It will be seen that the metering tube 18 is adjusted upwardly and downwardly relative to the metering valve 74 by an appropriate rotation of the knob 78. When the knob 78 is rotated clockwise, as viewed looking down on the valve as shown in FIG. 3, the tube 18 will be moved upwardly from the position shown in FIG. 5 to a raised position as illustrated ir 1 FIG. 6. The knob 78 may be provided with suitable calibration indicia to permit the user to adjust the metering valve 74 accurately relative to the slot 73 to predetermined settings so as to obtain the de- It will be understood that the height I sired time delay. and the width of the slot 73, and the size of the metering valve 74 and the valve chamber 60, may be made to any dimensions to obtain the desired rates of flow and timed delay. For example in one illustrative embodiment, the

The wave washer 82 is adapted to be seated in the 6 slot 73 was approximately .280 of an inch in height and .005 of an inch in width.

The time delay unit of the present invention is adapted for two primary uses, namely, for timing-in and timing-out operations. A timing-in operation in a fluid circuit for controlling the flow of pressurized fluid to a fluid cylinder or the like comprises a time delay interval during the fluid inlet period, and a free flow of the fluid from the cylinder upon reversal of flow of fluid initiated by a signal from a directional flow control valve in the circuit. A timing-out operation in a fluid circuit for controlling the flow of pressurized fluid from a fluid cylinder or the like comprises a free flow of fluid during the fluid inlet period, and a time delay interval during the return flow of fluid from the cylinder, which return flow is initiated by a signal from a directional flow control valve in the circuit.

For a timing-in operation the time delay unit is connected in a pressurized air system so that the pressurized air enters from the right side of the unit as viewed in FIG. 5, to provide a time delay control over the pressurized air being supplied to air cylinder or the like. The timing-in operation starts when the directional flow control valve in the system is operated to permit flow of pressurizedair to the time delay apparatus. At the start of a timing-in operation the time delay apparatus would be in the condition shown in FIG. 5. The air under pressure would flow into the chamber 11 and against the accumulator exhaust valve piston 47 to seal the accumulator chamber exhaust passage 44. Air under pressure also passes through the filter 69 and thence through the passage 67 and against the metering means inlet valve piston 70 to shift it to the left, as viewed in FIG. 5, to the open position. The pressurized air then flows through the piston chamber66 and the passage 65 into the inner end of the metering control recess 62, and thence through the wave washer recess 83, the axial recess 84, and through the metering slot 73 into the metering valve chamber 60. The rate of flow of the pressurized air into the metering valve chamber 60 would be determined by the effective open area of the slot 73 as determined by the position of the metering tube 18 with respect to the metering valve 74. The air under pressure passes from the metering valve chamber 60 downwardly through the metering tube axial bore 60a and into the tongue slot 58. There is clearance between the tongue 59 and the diameter of the piston 55, as shown in FIG. 7, and the pressurized air will pass into the accumulator chamber.

The air pressure will build up in the accumulator chamber until a predetermined air pressure is reached. The pressurized air in the accumulator chamber acts on the lower end of the accumulator differential piston 50 and when the predetermined air pressure is present in the accumulator chamber, the accumulator piston 50 will be moved upwardly and the flow valve 19 will be shifted to the open position shown in FIG. 6 to permit free flow of pressurized air through the time delay unit to the device being controlled.

It will be seen from an inspection of FIGS. 7 and 9, that when the accumulator piston 50 is in the inoperative position, it will be seated on the

cover projections

32 and 33, as indicated by the broken lines in FIG. 7, so as to decrease the initial effective operating area of the lower enlarged end of the piston. Substantially onehalf of the differential area of the piston 50 is thus covered, as compared to the area of the flow valve being acted on by air in the control chamber, when the air pressure initially moves the accumulator piston 50 upwardly. When the accumulator piston 50 breaks away from its inoperative position, as shown in FIG. 5, the effective differential operating area of the piston increases in a substantial 2 to 1 ratio. This last mentioned feature of the time delay unit of the present invention provides a positive and complete opening of the flow valve 19, with a snap action, when the predetermined opening air pressure is built up in the accumulator chamber.

When the inward flow of pressurized air to the device being controlled is reversed upon a signal from the directional flow control valve in the air system, the air will flow through the time delay unit with a free flow action to the right, as viewed in FIG. 5. The exhausting air under pressure will move the inlet valve piston 70 to the closed position and the air pressure in the accumulator chamber will move the exhaust valve piston 47 to the open position to permit the air in the accumulator chamber to be exhausted through the vent passage 46. The exhausting air under pressure in the free flow chamber 12 will engage the reduced inner end of the accumulator piston 50 and move it downwardly to the position shown in FIG. 5. The flow valve 19 will be held in the open position shown in FIG. 6 by means of the exhausting air moving successively through the chambers 12 and 11. When the air pressure in the free flow chamber 12 drops a predetermined amount, the spring 24 will close the flow valve 19 and the delay unit will be in a condition for a further timing-in operation.

For a timing-out operation the delay apparatus would be connected in a pressurized air system to permit free flow of pressurized air through the delay apparatus from the left side thereof, as viewed in FIG. 5, and into the device being controlled upon a signal from the directional flow control valve in the system. The pressurized air would flow freely to the cylinder or other device being controlled because the flow valve 19 would be shifted to the open position shown in FIG. 6 by means of the air pressure operating on the lower side thereof. The

pressurized air would engage the inlet valve piston 70 and shift it to the right to the closed position as shown in FIG. 5. The pressurized air passing through chamber 11 would also shift the accumulator valve piston 47 to the closed position, to the left as viewed in FIG, 5, to close the exhaust system for the accumulator chamber.

When the cylinder or other device being operated by the free flow of pressurized air has completed its function, an exhaust signal would be given by the directional flow control valve in the system andthe metering means would be operated to provide a timing-out delay period as described hereinafter. The pressurized air in the chamber 12 would be exhausted and the pressurized air in the system between the device being controlled and the .flow valve 19 would be trapped. The trapped pressurized air would shift the metering means inlet valve piston 70 to the open position, to the left as viewed in FIG. 5, to admit pressurized air to the metering valve chamber 60. The pressurized air will flow from the metering valve chamber v60 down into the accumulator chamber and build up to the point where the differential accumulator piston 50 will be moved upwardly to the position shown in FIG. 6 to open the flow valve 19 and terminate the timing-out delay period. The pressurized air pressure is thus exhausted from the device being controlled and the directional flow control valve of the system could be operated to initiate a new timing-out operation.

The delay unit of the present invention is adapted to provide a wide range of time delay. For example, in a fluid system where the line pressure is about 80 pounds per square inch with a possible plus or minus fluctuation of 10 pounds per square inch, the time delay unit may be adjusted to provide time delays of from zero to one minute duration with an accuracy of within two percent.

While it will be apparent that the preferred embodiment of the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What I claim is:

1. A time delay apparatus for controlling the flow of pressurized fluid in a fluid circuit, comprising: a body having a first port and a second port; a passageway formed through said body for connecting said ports; a flow valve flow valve for positioning the flow valve in the other of said positions after a predetermined time delay; and,

pressurized fluid metering means in said body for admitting a metered flow of pressurized fluid into said accumulator means for operating the same in the predetermined time delay cycle for timing the operation of said accumulator means.

2. A time delay apparatus for controlling the flow of pressurized fluid in a fluid circuit, comprising: a body having a first port and a second port; a passageway formed through said body for connecting said ports; a flow valve operatively mounted in said passageway for controlling pressurized fluid flow therethrough and being shiftable between a closed position and an open position; means engageable with said flow valve for positioning the flow valve in one of said positions; accumulator means in said body including an accumulator'chamber and an accumulator piston operatively mounted in said chamber movable relative to and engageable with said flow valve for positioning the flow valve in the other of said positions after a predetermined time delay; and, pressurized fluid metering means in said body for admitting a metered flow of pressurized fluid into said accumulator chamber for moving said piston in the predetermined time delay cycle for timing the operation of said accumulator means.

3. A time delay apparatus for controlling the flow of pressurized fluid in a fluid circuit, comprising: a body having a first port and a second port; a passageway formed through said body for connecting said ports and including a control fluid chamber and a free flow fluid chamber connected by a valve bore; a flow valve operatively mounted in said valve bore for controlling pressurized fluid flow therethrough and being shiftable between a closed position and an open position; means engageable with said flow valve for positioning the flow valve in one of said positions; accumulator means in said body including an accumulator chamber and an accumulator piston operatively mounted in said chamber movable relative to and engagable with said flow valve for positioning the flow valve in the other of said positions after a predetermined time delay; and, pressurized fluid metering means in said body for admitting a metered flow of pressurized fluid into said accumulator chamber for moving said piston in the predetermined time delay cycle for timing the operation of the accumulator means.

4. A time delay apparatus as defined in claim 3, wherein: said accumulator means includes an exhaust means for exhausting the pressurizedfluid from the accumulator chamber to the exterior of the body when a predetermined pressure differential exists between the fluid pressures in the accumulator chamber and the control fluid chamber.

5. A time delay apparatus as defined in claim 4, wherein: said exhaust means includes an exhaust passageway, an exhaust valve operatively mounted in said exhaust passageway and being in communication with said control fluid chamber and shiftable by fluid under pressure in the control fluid chamber to a normally closed position to block said exhaust passageway so long as a predetermined pressure differential exists between the fluid pressure in said control fluid chamber and the fluid pressure in said accumulator chamber.

6. A time delay apparatus as defined in claim 5, wherein: the surface area of the exhaust valve engageable by the pressurized fluid in the control fluid chamber is greater than the cross sectional area of the exhaust passageway closed by the exhaust valve to provide a pressure differential on the exhaust valve to maintain it in the closed position when the fluid pressure in the control fluid chamber fluctuates.

7. A time delay apparatus as defined in claim 3, wherein: the means engageable with said flow valve for positioning the flow valve in said one of said positions is a spring means disposed in said control fluid chamber and which is compressible to permit the accumulator piston to position the flow valve in said other position and adapted to position the flow valve in said one position without assistance from the accumulator piston.

8. A time delay apparatus as defined in claim 3, wherein: said pressurized fluid metering means includes a metering fluid passageway interconnecting said control fluid chamber and said accumulator chamber, an adjustable metering valve operatively mounted in said metering passageway to provide a predetermined timed flow of pressurized fluid into said accumulator chamber, and a pressurized fluid inlet valve in said metering passageway and shiftable to an open position by fluid entering the metering passageway, and being in communication with said free flow fluid chamber and shiftable by fluid under pressure in said free flow fluid chamber to a closed position to block said metering passageway when a predetermined pressure diflerential exists between the fluid pressure in said control fluid chamber and the fluid pressure in said free flow fluid chamber.

9. A time delay apparatus as defined in claim 8, wherein: the Working surface area of the fluid inlet valve engageable by the pressurized fluid in the free flow fluid chamber is greater than the cross sectional area of the metering passageway area blocked by the inlet valve.

-10. A time delay apparatus as defined in claim 8, wherein: said metering valve includes a tu-be having a bore therethrough forming an exit part of said metering passageway, one end of said bore being connected to said accumulator chamber, the other end of said bore being connected to a metering valve chamber, said metering valve chamber having a slot formed in one side thereof and communicating with an inlet part of the metering passageway, a valve pin mounted in said metering valve chamber, means for adjusting said tube for moving said slot relative to said valve pin for controlling the rate of flow of pressurized fluid through the metering passageway.

11. A time delay apparatus as defined in claim 8, wherein: said accumulator means includes means for partially enclosing the accumulator pressure fluid engaging end of the accumulator piston when it is in the inoperative position so as to provide an increased piston fluid pressure working area after the initial opening movement of the accumulator piston.

12. A time delay apparatus as defined in claim 10, wherein: said metering valve tube is disposed in said body perpendicularly to the line of fluid flow through said body, and said tube extends through said chambers and said valve bore.

13. A time delay apparatus as defined in claim 3, wherein: said accumulator chamber includes a piston cylinder portion and said accumulator piston is a differential piston operatively mounted in said piston cylinder portion and is provided with a reduced end extended into the free flow fluid chamber, and, means for venting said piston cylinder portion of the accumulator chamber to the exterior of the body.

14. A time delay apparatus as defined in claim 3, wherein: said pressurized fluid metering means includes a metering fluid passageway interconnecting said control fluid chamber and said accumulator chamber, and, a pressurized fluid inlet valve in said metering passageway and shiftable to an open position by fluid entering the metering passageway, and being in communication with said free flow fluid chamber and shiftable by fluid under pressure in said free flow fluid chamber to a closed position to block said metering passageway when a predetermined pressure differential exists between the fluid pressure in said control fluid chamber and the fluid pressure in said free flow fluid chamber.

15. A time delay apparatus for controlling the flow of pressurized fluid in a fluid circuit, comprising: a body having a first port and a second port; a passageway formed through said body for connecting said ports and including a control fluid chamber and a free flow fluid chamber connected by a valve bore; a flow valve operatively mounted in said valve bore for controlling pressurized fluid flow therethrough and being shiftable between a closed position and an open position; means engageable with said flow valve for positioning the flow valve in one of said positions, accumulator means in said body movable relative to and engageable with said flow valve for positioning the flow valve in the other of said positions after a predetermined time delay; and, pressurized fluid metering means in said body connected to said control fluid chamber for admitting a metered flow of pressurized fluid from the control chamber into said accumulator means to maintain a constant relationship between the pressurized fluid in the fluid circuit and the pressure required to operate the accumulator means in a predetermined time cycle for timing the operation of the accumulator means.

References Cited by the Examiner UNITED STATES PATENTS 2,201,513 5/1940 Ackerman 137-50543 X 2,676,612 4/ 1954 Stevenson 1-37490 X 2,680,453 6/1954 Prijatel 137-490 2,830,784 4/1958 Placette 251-50 X 2,981,277 4/1961 Gilmont 137-509 X 3,004,686 10/ 1961 McKee 137-5 05 .25 X

ISADOR WEIL, Primary Examiner. H. WEAKLEY, Assistant Examiner.

Claims

1. A TIME DELAY APPARATUS FOR CONTROLLING THE FLOW OF PRESSURIZED FLUID IN A FLUID CIRCUIT, COMPRISING: A BODY HAVING A FIRST PORT AND A SECOND PORT; A PASSAGEWAY FORMED THROUGH SAID BODY FOR CONNECTING SAID PORTS; A FLOW RATE OPERATIVELY MOUNTED IN SAID PASSAGEWAY FOR CONTROLLING PRESSURIZED FLUID FLOW THERETHROUGH AND SHIFTABLE BETWEEN A CLOSED POSITION AND AN OPEN POSITION; MEANS ENGAGEABLE WITH SAID FLOW VALVE FOR POSITIONING THE FLOWL VALVE IN ONE OF SAID POSITIONS; ACCUMULATOR MEANS IN SAID BODY MOVABLE RELATIVE TO SAID FLOW VALVE AND ENGAGEABLE WITH SAID FLOW VALVE FOR POSITIONING THE FLOW VALVE IN THE OTHER OF SAID POSITIONS AFTER A PREDETERMINED TIME DELAY; AND, PRESSURIZED FLUID METERING MEANS IN SAID BODY FOR ADMITTING A METERED FLOW OF PRESSURIZED FLUID INTO SAID ACCUMULATOR MEANS FOR OPERATING THE SAME IN THE PREDETERMINED TIME DELAY FOR OPERATING THE SAME IN THE PREDETERMINED LATOR MEANS.