US3351085A - Control apparatus - Google Patents

Description

Nov. 7, 1967 w. F. ALLINGHAM 3,351,085

CONTROL APPARATUS Filed July 12, 1965 3 Sheets-Sheet 1 ON OFF OPERATOR INVENTOR.

WALTER -E ALLINGHAM.

JTTOP/Vfy Nov. 7, 1967 w. F. ALLINGHAM 3,351,085

CONTROL APPARATUS Filed Jul 12, 1965 3 Sheets-Sheet 2 @1111"; 1}; Ld'PosmoN 3 I N VEN TOR.

WALTER F ALUNGHAM BY Filed July 12, 1965 Nov. 7, 1967 w. F. ALLINGHAM 3,351,085

CONTROL APPARATUS 3 Sheets-Sheet .3

INVENTOR WALTER E ALLINGHAM Jaw/ 6 ATTORNEY United States Patent 3,351,085 CONTROL APPARATUS Waiter F. Allingham, Torrance, Calif., assignor to Honeywell Inc., Minneapolis, Minn., a corporation of Delaware Filed .luly 12, 1965, Ser. No. 471,347 17 Claims. (Cl. 137-495) This invention relates to control apparatus and more particularly to a pressure responsive modulating control valve. Specifically, the invention relates to a pressure responsive exhaust valve for use in controlling a main valve of the type having a main closure member which is operated in response to the pressure in a pressure chamber under the control of the exhaust valve, and wherein the exhaust valve is operated in response to the pressure at the outlet of the main valve so that the main valve is operated to maintain a substantially uniform outlet pressure therefrom. The exhaust valve includes further pressure operated means and time delay means associated therewith which is effective, a predetermined time after pressure is initially supplied to the valve, to vary the loading on the pressure responsive exhaust valve so that the exhaust valve then operates only in response to a substantially greater pressure than that to which it initially responds. This causes the main valve to open initially to a minimum flow position and then, after a time delay, to open to a full flow position and to provide outlet pressure regulation at each of the flow levels.

The invention also provides means for selectively adjusting the minimum and full flow operating levels of the valve. Further, the invention contemplates the utilization, with the structure discussed above, of a manually operable means selectively operable to render the pressure responsive additional loading means inoperative so that the valve will continuously respond to the relatively low pressure.

My modulating exhaust valve is particularly useful in connection with a servo valve system wherein the main valve is operated by a movable wall which is responsive to fluid pressure in a main control or pressure chamber and wherein there is provided a first fluid passage be tween the inlet and the pressure chamber, a second fluid passage between the pressure chamber and the outlet, a two position valve in one of the passages and my exhaust valve in the other. The exhaust valve is connected so that it is operated by outlet pressure to maintain a uniform pressure at the outlet of the main valve. The further pressure operated means is connected either to the outlet or to the pressure chamber of the main valve so that, a predetermined time after the main valve opens, the exhaust valve is additionally loaded so that the valve operates at a greater pressure.

Various objects and advantages of my invention will become apparent upon reading the following detailed description of two preferred embodiments thereof wherein reference is made to the accompanying drawing. In the drawing:

FIGURE 1 is a schematic representation of a servo-type valve utilizing, as one of the controllers or pilot valves therefor, a modulating exhaust valve constructed according to my invention.

FIGURE 2 is a plan view of the interior of an exhaust valve constructed according to my invention and including a high-low selector member.

FIGURE 3 is a crosssectional view taken generally along line 3-3 of FIGURE 2.

FIGURE 4 discloses schematically the exhaust valve of my invention modified with another type of high-low selector apparatus.

FIGURE 5 discloses an exhaust valve constructed according to another form of my invention.

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FIGURE 6 is a longitudinal cross-sectional view taken generally along line 6--6 of FIGURE 5.

FIGURE 1 discloses a servo-type pressure regulator valve which utilizes a modulating exhaust valve constructed according to my invention as a pilot valve to control the position of the main valve. While my invention lies in the construction of the pressure operated modulating exhaust valve, it is believed necessary, in order to properly disclose my invention, to describe one environment in which it has utility. In FIGURE 1, reference numeral 10 generally designates the servo-type pressure regulator. This regulator includes a main valve portion 11, a two position servo control valve 12 and a modulating pressure responsive servo valve 13, the latter being constructed according to my invention. Main valve 11 has an inlet 14 and an outlet 15 separated by a wall 16 having an aperture 17 formed therethrough. Cooperable with aperture 17 is a main valve closure member 20 which is operably connected to a diaphragm or other movable wall 21 which separates the body of the main valve, on the outlet side of wall 16, into an outlet chamber 22 and a pressure or control chamber 23. A spring 24 urges diaphragm 21 toward chamber 23 and closure member 20 to a closed position. Between inlet 14 and wall 16 is an inlet chamber 25 which may have a manually operable valve 26 disposed therein. This manual valve may be a conventional disk or plug type valve with any appropriate manual operator (not shown). Manual valve 26 may also control flow through a passage 27 which by-passes the main valve closure member and is adapted to be connected to a pilot burner (not shown).

A passage 30, which may include a flow restriction 31, connects inlet chamber 25 to the interior of the two position control valve 12. A further passage 32 connects the interior of control valve 12 to pressure chamber 23. A passage 33 in control valve 12 connects to a main chamber 34 in the control valve which in turn is: connected, by a passage 35, to outlet chamber 22 of the main valve. A valve closure member 36 is operably connected to an on-off type operator 37 in control valve 12 and has a normal position wherein passage 30 is closed 017 and passages 32 and 33 are connected. In this normal position, pressure chamber 23 is connected to outlet chamber 22 and hence is exhausted. When the operator 37 is energized, the valve closure member 36 blocks passage 33 and opens passage 30 so that the pressure chamber 23 of the main valve is connected to inlet chamber 25 and this inlet pressure is sufiicient to overcome the bias of spring 24 and to open the main value closure member 20.

When control valve 12 is open to supply inlet pressure to the pressure chamber 23, the amount of fluid pressure in chamber 23, and consequently the position of the main valve closure member 20, is controlled by the modulating exhaust valve .13. For the sake of clarity, modulating valve 13 is shown somewhat schematically in FIGURE 1 but is shown more realistically in FIGURES 2 and 3. Valve 13 has a main body portion 40 which has an opening 40a therethrough extending from top to bottom. The bottom of this opening is covered by a first movable wall such as a diaphragm 41 which is sealed between the bottom of body member 40 and the upper surface of another body member 42. The upper end of body member 40 is closed by a second movable wall such as a diaphragm 43 which has its periphery clamped between the upper end of body member 40 and the lower end of a further body member 44. Intermediate body member 42 and the under surface of diaphragm 41 is an operating chamber 45 and intermediate body member 44 and the upper surface of diaphragm 43 is a timing chamber 46. Thus, diaphragms 41 and 43 will be referred to as an operating diaphragm and a timing diaphragm, respectively. Formed in body member 42 is a chamber 47 which is connected to pressure chamber 23 of the main valve by a passage 48. Chamber 47 is connected to operating chamber 45 by a port 50. Disposed in chamber 45 and cooperable with port 50 to control fluid flow therethrough, is a spherical valve closure member 51 which is normally urged into closing engagement with port 50 by operating diaphragm 41. Timing chamber 46 is connected to chamber 47 by a passage 52 which has a time delay flow restriction 53 disposed therein.

The opening 40a in body member 40, intermediate diaphragms 41 and 43, is preferably connected to atmosphere by a restricted passage 54. cantilevered in body member 40, as at 55, is a pair of lever members 56 and 57 which are bent so that they extend in generally spaced parallel relationship across the interior of body member 40 and generally parallel to diaphragms 41 and 43. Levers 56 and 57 have aligned apertures 60 and 61 respectively. At their free ends levers 56 and 57 have tab portions 62 and 63, respectively, which are bent to form an acute angle with the lever members. These tabs are engaged by the conical end of adjustment screws 64 and 65. Advancement of adjustment screw 65 will result in deflecting the free end of lever 57 downwardly and advancement of adjustment screw 64 will result in deflecting the free end of lever 56 upwardly. Thus, these adjustment screws provide a means for selectively adjusting the position of the two lever members with respect to each other and also with respect to diaphragm 41. Ent-rapped between levers 56 and 57 is a spring engaging member 66 which has cylindrical body portion 67 and an outwardly extending annular flange 68. Flange 68 is of a diameter sufficiently-large so that it cannot pass through the apertures 61) and 61 of the levers, but cylindrical portion 67 is sufficiently small in diameter to extend through aperture 61 in lever 57.

Disposed between operating diaphragm 41 and spring engaging member 66 is a first loading spring 70 which urges diaphragm 41 in a direction to close valve closure member 51 against port 50 and also urge-s spring engaging member 66 to a position so that flange 68 engages the underside of lever 57. Disposed between diaphragm 43 and the upper surface of flange 68 is another spring 71 which is of substantially negligible strength with respect to the strength of spring 70, but which is sufficiently strong to normally lift diaphragm 43 away from the upper end of spring engaging member 66 when timing chamber 46 is evacuated. It will be noted that the loading applied to diaphragm 41 by spring 70 (with diaphragm 43 held away from spring engaging member 66) is determined by the position of lever 57 which is in turn determined by the position of adjustment member 65.

' As will be seen hereinafter, when a description of the operation of the regulating valve is given, under certain circumstances pressure builds up in timing chamber 46 and forces timing diaphragm 43 downwardly and into engagement with the upper end of spring engaging member 66. Under these circumstances diaphragm 43 pushes the spring engaging member downwardly until flange 68 engages the upper surface of lever 56 and thus additionally loads operating diaphragm 41. The loading on diaphragm 41, whenthis occurs, is determined by the position of lever 56 which in turn is determined by the position of adjustment member 64.

' The operation of the structure of FIGURE 1 will now be described. With two position control valve 12 in its off position and valve closure member 36 blocking passage 30, as disclosed in FIGURE 1, pressure chamber 23 is connected to outlet chamber 22 and main closure member 20 is closed. At this time the pressure in outlet chamber 22 and in pressure chamber 23, as well as in operating and timing chambers 45 and 46, is substantially at atmospheric since outlet of the valve is normally connected to a burner (not shown). When it is desired to open the main closure member 20, operator 37 of valve 12 is energized and valve closure member 36 is shifted to a position so that it closes off passage 33 and opens passage 30. This connects pressure chamber 23 to inlet chamber 25 and the inlet pressure is effective to overcome the force of spring 24 and to open main valve closure member 20. This causes an increase in the pressure in outlet chamber 22 and in operating chamber 45 which is connected to outlet chamber 22 by the substantially unrestricted passage 35. As soon as the pressure in chamber 45 is suflicient to overcome the loading on operating diaphragm 41 by spring 70, diaphragm 41 is lifted and valve 51 opens to allow pressure to be exhausted from chamber 47 (which is connected to pressure chamber 23) through passage 50 to outlet chamber 22. This tends to reduce the pressure in chamber 23 and thus to slightly close main closure member 20. It will be seen that this arrangement will maintain a pressure in pressure chamber 23 which is sufficient to position main valve closure member 20 so that it maintains a constant outlet pressure which is determined by the loading on diaphragm 41.

The pressure in chamber 47 gradually is communicated to timing chamber 46 through passage 52 and the restriction 53. After a period of time determined by the size of restriction 53, the pressure in timing chamber 46 is suflicient to move diaphragm 44 downwardly and to engage the upper end of spring engaging member 66. After a period of time this pressure becomes sufficient to push member 66 downward until flange 68 engages the upper surface of lever 56. This additionally loads diaphragm 41 so that a substantially greater pressure in outlet chamber 22 and operating chamber 45 is necessary to lift valve 51. Thus, the valve system is caused to regulate at a substantially increased outlet pressure.

The modulating exhaust valve with the pressure operated step feature is shown less schematically in FIGURES 2 and 3. These figures also disclose the valve modified to I include manual means for rendering the diaphragm 43 inoperative so that it will not additionally load operating diaphragm 41 after the time delay if it is desired that the valve continuously operate at the low or initial regulating level. This function is provided by the addition of a shaft 75 rotatably mounted in body member 40 and having one end extending beyond the outer edge of body 40 and fitted with an operating knob 76. Shaft 75 may be sealed with respect to body member 46 by appropriate means such as an O-ring 77. Shaft 75 also extends into the interior of body member 40 and has mounted at its interior end an abutment arm 80. Abutment arm may be attached to the end of shaft 75 by any appropriate means, such as simply crimping over the end of the shaft as at 81. Abutment arm 80 includes a portion 86a which extends generally perpendicular to shaft 75 and a portion 80b which extends generally parallel to, and offset from, the axis of shaft 75. When it is desired that the valve regulate continuously at the low or initial pressure level, knob 76 is rotated to a position wherein portion Stlb of arm 86 physically engages the underside of timing diaphragm 43 and restrains it from moving downward in response to a build up of pressure in timing chamber 46. Thus, timing diaphragm 43 is ineffective to additionally load operating diaphragm 41 and the valve operates continuously at the low or initial pressure level whenever two position control valve 12 is energized.

When it is desired that the valve operate in its high position, knob 76 is rotated so that portion 80b of abutment arm 80 is disposed intermediate diaphragms 41 and 43 so that it does not interfere with the movement of timing diaphragm 43. When this is done the operation of the valve is identical to that described in connection with FIGURE 1. In other words, the valve initially operates at a low or initial pressure level determined by the position of lever 57 and, after a time delay sufficient to allow a build up of pressure in timing chamber 46, diaphragm 43 moves downward and additionally loads the operating diaphragm so that the valve operates at a substantially greater pressure.

Another way of obtaining this high-low operation is disclosed schematically in FIGURE 4 where modulating valve 13 is also disclosed schematically. In this arrangement, a passage 90 connects timing chamber 46 to the interior of a two position valve 91 which has another passage 92 which is connected to an area of low pressure such as an area adjacent the fuel burner (not shown). Inside valve 91 is a valve closure member 93 which may be manually or otherwise operated. When closure member 93 is in its closed position, as shown in FIGURE 4, passage 90 is blocked off and the operation of timing chamber 46 and timing diaphragm 43 is exactly as described in connection with FIGURES 1, 2 and 3. However, if valve closure member 93 is open so that passage 90 is connected to passage 92, the pressure which normally would build up in timing chamber 46 is bled off to the burner and sufiicient pressure is never applied to diaphragm 43 to move it down to additionally load the operating diaphragm 41.

Another modulating exhaust valve constructed according to my invention, but diifering somewhat in the structural details thereof, is disclosed in FIGURES 5 and 6. In the following description of this embodiment of my invention, elements similar to, or corresponding to, elements disclosed in FIGURES 1 through 4 have been given identical identification numerals but preceded by the numeral 1. In other words, the main body portion of the exhaust valve was identified by the numeral 40 in the preceding figures and in the embodiment disclosed in the FIGURES 5 and 6 it is identified by the numeral 140. These elements which do not have a substantial equivalent in FIGURES 1 through 4 will be identified by numerals beginning with the numeral 200.

In this embodiment, body portions 140 and 142 have clamped therebetween the peripheral portion of an operating diaphragm 141 which is responsive to pressure in an operating chamber 145. Operating diaphragm 141 operably engages an exhaust valve closure member 151 which controls the flow of fluid through a port 150. A timing diaphragm 143 is clamped along its periphery between body members 140 and 144 and there is formed between diaphragm 143 and body member 144 a timing chamber 146. Between diaphragms 141 and 143 is a chamber 140a which is preferably connected to atmosphere by a passage (not shown).

Cantilevered in chamber 140a is a first lever member 157 which may be attached to body member 140 by appropriate means such as rivets 155. Lever 157 has a portion extending generally parallel to the operating and timing diaphragms and is sufiiciently resilient so that its free end may be deflected toward and away from operating diaphragm 141. An adjustment member 165 is threaded into body member 140 and engages an abutment tab 200 on the free end of lever 157 to deflect lever 157 toward diaphragm 141. Member 165 is thus selectively movable to determine the position of the free end of lever 157 in a direction away from operating diaphragm 141.

Lever 157 has, adjacent its fixed end, a pair of hooklike members 201 which cooperate with a corresponding pair of tabs 202 on a second lever member 156 and act as a pivot for lever 156 with respect to lever 157. Lever 156 has a free end which extends generally to about the same extent as does the free end of lever 157. Adjacent their free ends, levers 156 and 157 have a pair of coop crating tabs 203 and 204, respectively, which limit the amount of movement of the free end of lever 156 away from the free end of lever 157. Lever 156 has at its free end three abutment tabs, 205, 206 and 207. Tabs 205 and 207 cooperate with a movable adjustment member 164 and a fixed abutment member 208, respectively. Adjustment member 208 is press-fitted into body member 140 and cannot be moved once it has been forced into the body. This member provides a factory adjustment which limits the pivotal movement of lever 156 toward operating diaphragm 141. Adjustment member 164 provides a field adjustable limit of the pivotal movement of member 156 towards operating diaphragm 141. Tab 206 on lever 156 cooperates with an abutment surface 210 which is an integral part of body member and. provides an absolute limiting position of the free end of lever 156 with respect to operating diaphragm 141 irregardless of the adjustment members 164 and 208. Similarly, lever 157 has adjacent its free end an abutment tab 211 which cooperates with an abutment portion 212 on body member 140 to limit the displacement of the free end of lever 157 in a direction away from operating diaphragm 141.

Lever member 156 has formed therein a portion 166 which acts as a spring engaging member or portion which engages one end of a loading spring 170, the other end of which acts upon operating diaphragm 141 and urges it to a position wherein it closes exhaust valve closure member 151 against passage 150. A substantially lighter spring 171 acts between the upper surface of lever 156 and the under surface of timing diaphragm 143 and normally maintains timing diaphragm 143 out of engagement with lever 156.

The operation of this embodiment of my invention is substantially the same as that discussed in connection with the previous figures. Timing chamber 146 is connected by a restricted passage, such as passage 152, to an area which is normally at a pressure insufficient to cause timing diaphragm 143 to move down in opposition to the bias of spring 1'71 but which area is supplied with a higher pressure when the main valve is operated to an open position and pressure is supplied to the area to which passage 150 is connected. Spring normally urges diaphragm 141 to .a position wherein it closes valve closure member 151, and it urges lever 156 in a clockwise direction so that abutment tab 263 thereon engages the underside of abutment tab 2114 on lever 157. The position or" the free end of lever 157 is determined by the adjustment of member 165. This corresponds to a minimum loading condition for diaphragm 141. Upon initial application of pressure to the valve, operating diaphragm 141 responds to a relatively low pressure corresponding to this minimum loading condition. As pressure builds up in timing chamber 146, timing diaphragm 143 is driven downwardly so that it engages lever 156 and moves it in a counterclockwise direc tion to compress loading spring 170. The amount of movement which lever 156 can make is determined by the position of adjustment member 164 which will thus determine the maximum loading condition of the operating diaphragm. When the operating diaphragm is so loaded, the valve responds only to a substantially greater pressure.

It will be appreciated that means for providing highlow selection for the operation of the valve may be provided by simply adding to the structure disclosed in FIG- URES 5 and 6 the high-low selector apparatus disclosed in FIGURES 2 and 3 or that disclosed in FIGURE 4.

I have described certain preferred embodiment of my invention and one environment in which it finds utility. From this description it can be seen that my invention provides a simple, reliable modulating exhaust valve for controlling a main pressure operated valve. The structure includes pressure operated means for varying the loading on the exhaust valve a predetermined time after initial operation of the valve to cause the exhaust valve to then regulate at a substantially greater pressure. In addition, I have provided means whereby this stepping function may be selectively manually overridden so that the valve will operate only at the lower pressure if this operation is desired. In view of this disclosure of these particular preferred embodiments of my invention, various modifications may be apparent to those skilled in the art without departing from the scope of my invention. For this reason it is to be understood that the description herein is by way of example only and my invention is to be limited solely by the scope of the appended claims.

I claim:

1. A pressure responsive exhaust valve for use in controlling a main valve of the type having a main closure member biased to a closed position, a control chamber including a movable wall operably connected to the main closure member and responsive to pressure in the control chamber to open the closure member, and control valve means operable to a first position to connect the control chamber to pressure at the inlet of the main valve to cause opening of the main closure member, and operable to a second position to connect the control chamber to the outlet of the main valve to cause closure of the main closure member, the exhaust valve comprising: a body having a void therein; a pair of spaced, generally parallel diaphragms disposed in said void and dividing it into an operating chamber between the first of said diaphragms and said body and a timing chamber between the second of said diaphragms and said body, and a central chamber intermediate said diaphragms; first fluid passage means including a flow restriction and connecting said central chamber to atmosphere; second fluid passage means adapted to connect said operating chamber to the outlet of the main valve; third fluid passage means adapted to connect said operating chamber to the control chamber; an exhaust valve closure means cooperable with said third fluid passage to control fluid flow therethrough, said closure member being operably engaged by said first diaphragm and normally urged thereby to a position to close said third passage means, said first diaphragm being responsive to fluid pressure in said operating chamber for movement toward said central chamber to allow said closure member to open said third passage means; a pair of spaced generally parallel lever members cantilevered on said body in said central chamber and extending generally parallel to said diaphragms, said levers having a pair of aligned apertures thereth-rough, each of said levers having a calibration tab extending therefrom at an acute angle to said levers; a first adjustment member threaded into said body and extending into said central chamber generally parallel to said levers and engaging the calibration tab on the first of said levers so that said adjustment member may be selectively manipulated to deflect said first lever toward or away from the second of said levers; a second adjustment member, similar to said first adjustment member and engaging the calibration tab on said second lever so that said second adjustment member may be selectively manipulated to deflect said second lever toward or away from said first lever; a generally cup-shaped member having an annular flange around its exterior, said member being entrapped between said lever members with the closed end of the cup extending through said second lever toward said second diaphragm; a first loading spring disposed between said cup-shaped member and said first diaphragm and urging said first diaphragm to a position to close said closure member with respect to said third passage and urging said cup-shaped member toward a position wherein the flange thereon engages said second lever; a second, substantially lighter spring intermediate said cup-shaped member and said second diaphragm and normally urging said second diaphragm away from the cupshaped member; and a restricted fluid passage adapted to connect said timing chamber to an area supplied with fluid pressure only during operation of the main valve in an open position so that, upon initial opening of the main valve, the exhaust valves opens in response to outlet pressure effective to overcome the loading on said first diaphragm which is determined by the setting of said first adjustment member to cause outlet pressure regulation at a first pressure level and, after a time delay determined by the size of the restriction in said restricted passage means, the pressure in said timing chamber becomes sufficient to overcome said second spring and moves said second diaphragm into engagement with said cup-shaped member and thereby moves said cup-shaped member so that said flange thereon abuts said first lever and addition ally loads said first diaphragm so that said exhaust valve opens only in response to a second relatively greater outlet pressure determined by the position of said second adjustment member and causes a step operation by the main valve and regulation at said second pressure.

2. The exhaust valve of claim 1 wherein means is associated with said second diaphragm for selective operation to render said second diaphragm inoperative to additionally load said first diaphragm after said time delay so that the valve operates continuously at said first pressure.

3. A pressure responsive exhaust valve for use in controlling the bleed from the control chamber of a main valve of the type having a main closure member biased to a closed position and a movable wall responsive to pressure in the control chamber to open the closure member, the exhaust valve comprising: a body having an operating chamber and a timing chamber therein, said chambers having first and second movable walls, respectively, each of said movable walls having one side exposed to fluid pressure in the corresponding chamber and the other side exposed to an area of low pressure; first fluid passage means adapted to connect said operating chamber to the outlet of the main valve; second fluid passage means adapted to connect said operating chamber to the control chamber; an exhaust valve closure member associated with said second passage means and operably connected to said first movable wall and operable thereby to control fluid flow through said second fluid passage means, fluid pressure in said operating chamber urging said first movable wall in a direction to open said exhaust valve member; a pair of spaced lever members cantilevered on said body; a first adjustment member threaded into said body and engaging the first of said levers so that the first adjustment member may be selectively manipulated to deflect said first adjustment member toward or away from the second of said levers; a second adjustment member, similar to said first adjustment member and engaging said second lever so that said second adjustment member may be selectively manipulated to deflect said second lever toward or away from said first lever; a spring engaging member disposed between said lever members and movable therebetween and operably engageable by said second movable wall upon application of fluid pressure to said timing chamber; a first loading spring operably connected to said engaging member and to said first movable wall and yieldably urging said first movable Wall to close said valve member and urging said engaging member into abutment with said second lever; a second, substantially lighter spring intermediate said engaging member and said second movable wall and normally urging said second movable wall away from operative engagement with said engaging member; and a restricted fluid passage adapted to connect said timing chamber to an area supplied with fluid pressure only during operation of the main valve to an open position so that upon initial opening of the main valve, the exhaust valve opens in response to a first outlet pressure on said first movable wall effective to overcome the loading thereon which is determined by the setting of said first adjustment member to cause outlet pressure regulation at said first pressure, and, after a time delay determined by the size of the restriction in said restricted passage means, the pressure in said timing chamber becomes sufficient to overcome said second spring and moves said second movable Wall into operative engagement with said engaging member and moves said engaging member so that it abuts said first lever and thereby additionally loads said first movable wall so that said exhaust valve opens only in response to a second relatively greater outlet pressure determined by the position of said second adjustment member and causes a step by the main valve and regulation at said second pressure.

4. An exhaust valve for use in controlling the bleed from the pressure chamber of a main valve of the type having a main closure member operated in response to the pressure in the pressure chamber, the exhaust valve comprising: a body having a void therein; a pair of spaced, generally parallel diaphragms disposed in said void and dividing it into an operating chamber and a timing chamber on opposite sides of said diaphragms and a central chamber intermediate said diaphragms; first passage means connecting said central chamber to atmosphere; second fluid passage means adapted to connect said operating chamber to the outlet of the main valve; third fluid passage means adapted to connect said operating chamber to the control chamber; an exhaust valve closure member in said operating chamber, operably engaged by said first diaphragm and normally urged thereby, in opposition to pressure in said operating chamber, to a position to close said third passage means; a pair of spaced generally parallel lever members mounted on said body in said central chamber and extending generally parallel to said diaphragms; a spring engaging member disposed between said lever members and movable there between; a first loading spring yieldably urging said first diaphragm to a position to close said closure member and urging said spring engaging member toward said second lever; a second, substantially lighter, spring normally urging said second diaphragm away from the spring engaging member; and a restricted fluid passage adapted to connect said timing chamber to an area supplied with fluid pressure only when pressure is applied to the pressure chamber of the main valve so that, upon initial opening of the main valve, the exhaust valve opens in response to outlet pressure effective to overcome the loading by said first spring and, after a time delay determined by the size of the restriction in said restricted passage, the pressure in said timing chamber overcomes said second spring and moves said second diaphragm into engagement with said spring engaging member and additionally loads said first diaphragm so that said exhaust valve opens only in response to a second relatively greater outlet pressure.

5. An exhaust valve for use in controlling the bleed from the pressure chamber of a main valve of the type having a main closure member operated in response to pressure in the pressure chamber, the exhaust valve comprising: a body having an operating chamber and a timing chamber therein, said chambers having first and second movable walls, respectively, each of said movable Walls having one side exposed to fluid pressure in the corresponding chamber and the other side exposed to an area of low pressure; first fluid passage means adapted to connect said operating chamber to the outlet of the main valve; second fluid passage means adapted to connect said operating chamber to the pressure chamber; an exhaust valve closure member associated with said second passage means and operable by said first movable wall to control fluid flow through said second fluid passage means, fluid pressure in said operating chamber urging said first movable wall in a direction to open said exhaust valve member; a pair of lever members mounted on said body; a spring-engaging member disposed between said lever members and movable therebetween and operably engageable by said second movable wall; a first loading spring disposed between said engaging member and said first movable wall and urging said first movable wall to a position to close said exhaust valve member and urging said engaging member into abutment with said second lever; a second, substantially lighter, spring intermediate said engaging member and said second movable wall and normally urging said second movable wall away from operative engagement with said engaging member; and a restricted fluid passage adapted to connect said timing chamber to an area normally at a relatively low pressure incapable of moving said second movable wall in opposition to said second spring and supplied with a higher pressure suflicient to overcome said second spring only when the main valve is operated to its open position so that, upon initial opening of the main valve, the exhaust valve opens in response to a first outlet pressure on said first movable wall and, after a time delay determined by the size of the restriction. in said restricted passage means, the pressure in said timing chamber overcomes said second spring and moves said second movable wall into operative engagement with said engaging member and moves said engaging member into abutment with said first lever to additionally load said first movable wall so that said exhaust valve opens only in response to a second relatively greater outlet pressure.

6. The exhaust of claim 5 wherein there is associated with said second movable wall, means selectively operable to render said second movable wall inoperative to additionally load said first movable wall after said time delay so that the valve operates continuously at said first pressure.

'7. A pressure responsive exhaust valve comprising: a body having an operating chamber and a timing chamber therein, said chambers having first and second movable walls, respectively, each of said movable walls having one side exposed to fluid pressure in the corresponding chamber and the other side exposed to an area of low pressure, said body having a valve port in said operating chamber; a valve closure member operable by said first movable wall to control fluid flow through said port, fluid pressure in said operating chamber urging said first movable wall in a direction to open said closure member; a pair of spaced lever members mounted on said body and spaced from said first movable wall; manual adjustment means associated with said levers and selectively movable in said body to adjust the position of said levers with respect to each other and with respect to said first movable wall; a spring engaging member disposed between said lever members and movable therebetween; a first loading spring between said engaging member and said first movable wall, urging said first movable wall to a position to close said closure member and urging said engaging member into abutment with said second lever; a second, substantially lighter, spring normally urging said second movable wall away from operative engagement with said engaging member; a restricted fluid passage adapted to connect said timing chamber to an area supplied with fluid pressure whenever pressure is applied to said operating chamber so that, upon initial application of pressure to said operating chamber, the closure member opens in response to a first pressure on said first movable wall effective to overcome the loading thereon determined by the position of said second lever, and, after a time delay determined by the size of the restriction in said restricted passage, the pressure in said timing chamber overcomessaid second spring and moves said second movable wall into operative engagement with said engaging member and thereby additionally loads said first movable wall so that said exhaust valve opens only in response to a second relatively greater pressure determined by the position of said first lever.

8. The exhaust valve of claim 7 wherein there is associated with said second movable wall, means selectively operable to render said second movable wall inoperative to additionally load said first movable wall after said time delay so that the valve operates continuously at said first pressure.

9. A pressure responsive exhaust valve for use in controlling a main valve of the type having an inlet and an outlet, a main closure member between the inlet and outlet and movable between open and closed positions to control flow therethrough, means biasing the main closure member to one of those positions, a movable wall operably connected to the closure member and operable in response to the pressure in a control chamber to move the closure member toward the other of those positions, a pilot valve operable between a first position wherein it connects the control chamber to the inlet and a second position wherein it connects the control chamber to the outlet, the exhaust valve comprising: a body having an opening therein; first and second movable walls in said body dividing said opening into three chambers including an operating chamber having said first movable wall as one wall thereof, a timing chamber having said second movable Wall as one wall thereof and an intermediate chamber between said first and second movable walls; first fluid passage means connecting said operating chamber to the control chamber of the main valve; second fluid passage means connecting said operating chamber to the outlet of the main valve; exhaust valve closure means cooperable with said first fluid passage means to control fluid flow therethrough, said exhaust valve being operably connected to said first movable wall, fluid pressure in said operating chamber urging said first movable wall toward a position wherein said exhaust valve closure means is opened; loading spring means operably engaging said first movable wall to urge it to a position to close said exhaust valve closure means; lever means mounted on said body and having a portion movable with respect thereto; spring engaging means operably engaging said loading spring means and being movable to vary the loading on said first movable wall, said spring engaging means being operably associated with said lever means and positioned accord ing to the position of said movable portion of said lever means, said spring engaging means being operably engageable by said first movable wall; adjustment means operably associated with said lever means and manually movable to select the limits of movement of said spring engaging means and thereby the maximum and minimum loading conditions of said first movable wall; yieldable biasing means normally urging said second movable wall out of operable engagement with said spring engaging means; and third fluid passage means, including a time delay fiow restriction, connecting said timing chamber to an area normally at a relatively low pressure incapable of moving said second movable wall in opposition to said yieldable biasing means and supplied with a higher pressure only when the main valve is operated to its open position so that, upon initial operation, said exhaust valve responds to a pressure corresponding to the minimum loading condition and maintains pressure at the outlet substantially constant at that pressure and, after a time delay due to said restriction, pressure in said timing cham ber causes said second movable wall to move said lever to its maximum loading position and said exhaust valve then responds only to a susbtantially greater pressure and maintains the outlet pressure substantially constant at said greater pressure.

10. The exhaust valve of claim 9 wherein there is associated with said second movable wall, means selectively operable to render said second movable wall inoperative to additionally load said first movable wall after said time delay so that the valve operates continuously at said first pressure.

11. The exhaust valve of claim 10 wherein the last named means is a manually movable abutment member selectively movable between a first position wherein it physically engages said second movable wall and thereby prevents it from moving into operative engagement with said spring engaging member, so that the valve operates only at said first pressure, and a second position wherein said abutment member does not interfere with movement of said second movable wall.

12. The exhaust valve of claim 10 wherein the last named means includes an exhaust passage connecting said timing chamber to atmosphere, and valve means in said exhaust passage selectively operable between an open position wherein it connects said timing chamber to atmosphere, so that pressure does not build up in said timing chamber to move said second movable wall into engagement with said spring engaging means, and a closed position wherein said exhaust passage is blocked.

13. A pressure responsive exhaust valve for use in controlling a main valve of the type having an inlet and an outlet, a main closure member between the inlet and outlet and movable between open and closed positions to control flow therethrough, means biasing the main closure member to one of those positions, a movable wall operably connected to the closure member and operable in response to the pressure in a control chamber to move the closure member toward the other of those positions, a two-position pilot valve operable between a first position wherein it connects the control chamber to the inlet and a second position wherein it connects the control chamber to the outlet, the exhaust valve comprising: a body having an opening therein; first and second movable walls in said body dividing said opening into three chambers including at atmospheric chamber intermediate said first and second movable walls, an operating chamber having said first movable wall as one Wall thereof, and a timing chamber having said second movable wall as one wall thereof; first fluid passage means connecting said operating chamber to the control chamber of the main valve; second fluid passage means connecting said operating chamber to the outlet of the main valve; exhaust valve closure means cooperable with said first fluid passage means to control fluid flow therethrough, said exhaust valve being operable connected to said first movable wall, fluid pressure in said operating chamber urging said first movable wall toward a position wherein said exhaust valve closure means is opened; loading spring means disposed in said atmospheric chamber and operably engaging said first movable wall to urge it to a position to close said exhaust valve closure means; lever means mounted on said body in said atmospheric chamber and having a portion movable in said chamber; spring engaging means disposed in said atmospheric chamber and operably engaging said loading spring means and being movable with respect thereto to vary the loading on said first movable wall, said. spring engaging means being operably associated with said lever means and positioned in said chamber according to the position of said movable portion of said lever means; adjustment means operably associated with said lever means and manually movable to select the limits of movement of said spring engaging member and thereby the maximum and minimum loading conditions of said first movable wall, said spring engaging means being disposed so that, upon application of fluid pressure to said timing chamber, said second movable wall operably engages said spring engaging means and moves it toward its maximum loading position; yieldable biasing means normally urging said second movable wall out of operable engagement with said spring engaging means; and third fluid passage means, including a time delay flow restriction, connecting said timing chamber to an area normally at a relatively low pressure incapable of moving said second movable wall in opposition to said yieldable biasing means and supplied with a higher pressure only when the main valve is operated to its open position so that, upon initial operation, said exhaust valve responds to a pressure corresponding to the minimum loading condition and maintains pressure at the outlet substantially constant at that pressure and, after a time delay due to said restriction, said second movable wall moves said spring engaging member to its maximum loading position and said exhaust valve responds only to a substantially greater pressure and maintains the outlet pressure substantially constant at said greater pressure.

14. A pressure responsive exhaust valve for use in controlling a main valve of the type having an inlet and an outlet, a main closure member between the inlet and out let and movable between open and closed positions to control flow therethrough, means biasing the main closure member to one of those positions, a movable wall operable connected to the closure member and operable in response to the pressure in a control chamber to move the closure member toward the other of those positions, a pilot valve operable between a first position wherein it connects the control chamber to the inlet and a second position wherein it connects the control chamber to the outlet, the exhaust valve comprising: a body having an opening therein; first and second movable walls in said body dividing said opening into three chambers including 13 an operating chamber having said first movable wall as one wall thereof, a timing chamber having said second movable wall as one wall thereof and an intermediate chamber between said first and second movable walls; first fluid passage means for connecting said operating chamber to the control chamber of the main valve; second fluid passage means for connecting said operating chamher to the outlet of the main valve; exhaust valve closure means cooperable with said first fluid passage means to control fluid flow therethrough, said exhaust valve being operably connected to said first movable wall, fluid pressure in said operating chamber urging said first movable wall toward a position wherein said exhaust valve closure means is opened; loading spring means operably engaging said first movable wall to urge it to a position to close said exhaust valve closure means; a lever pivotally mounted on said body and including a spring engaging portion operably engaging said loading spring means and movable to vary the loading on said first movable wall, said lever being operably engageable by said second movable wall; adjusting means including abutment means adapted to fix the extent of movement of said spring engaging portion to determine the maximum and minimum loading conditions respectively, on said first movable wall; said lever being disposed so that, upon application of fluid pressure to said timing chamber, said second movable wall operably engages said lever and moves it toward its maximum loading position; yieldable biasing means normally urging said second movable wall out of operable engagement with said spring engaging means; and third fluid passage means, including a time delay flow restriction, connecting said timing chamber to an area normally at a relatively low pressure incapable of moving said second movable wall in opposition to said yieldable biasing means and supplied with a higher pressure only when the main valve is operated to its open position so that, upon initial operation, said exhaust valve responds to a pressure corresponding to the minimum loading condition and maintains pressure at the outlet substantially constant at that pressure and, after a time delay due to said restriction, said second movable wall moves said lever to its maximum loading position and said exhaust valve responds only to a substantially greater pressure and maintains the outlet pressure substantially constant at said greater pressure.

15. A pressure responsive exhaust valve for use in controlling a main valve of the type having an inlet and an outlet, a main closure member between the inlet and outlet and movable between open and closed positions to control flow therethrough, means biasing the main closure member to one of those positions, a movable wall operably connected to the closure member and operable in response to the pressure in a control chamber to move the closure member toward the other of those positions, a pilot valve operable between a first position wherein it connects the control chamber to the inlet and a second position wherein itconnects the control chamber to the outlet, the exhaust valve comprising: a body having an opening therein; first and second movable walls in said body dividing said opening into three chambers including an operating chamber having said first movable wall as one wall thereof, a timing chamber having said second movable wall as one wall thereof and an intermediate chamber between said first and second movable walls; first fluid passage means connecting said operating chamber to the control chamber of the main valve; second fluid passage means connecting said operating chamber to the outlet of the main valve; exhaust valve closure means cooperable with said first fluid passage means to control fluid flow therethrough, said exhaust valve being operably connected to said first movable wall, fluid pressure in said operating chamber urging said first movable wall toward a position wherein said exhaust valve closure means is opened; loading spring means disposed in said atmospheric chamber and operably engaging said first movable 14 e wall to urge it to a position to close said exhaust valv closure means; a first lever member cantilevered on said body and extending generally parallel to said first movable wall in the chamber between said first and second movable walls and having a free end deflectable toward and away from said first movable wall; a second lever member pivoted on said body in the chamber between said first and second movable walls and having a free end portion movable toward and away from said first movable wall, said free end portion operably engaging said loading spring means so that movement toward and away from said first movable wall is effective to vary the loading thereon; means providing a lost motion connection between the free ends of said first and second lever members to limit the permissible pivotal movement of said second lever away from said first lever; first adjustment means for limiting the deflection of said first lever away from said first movable wall to determine the minimum loading condition on said first movable wall; second adjustment means cooperable with said second lever to limit its movement toward said first movable wall to determine the maximum loading condition for said first movable wall; said second lever being disposed so that, upon application of fluid pressure to said timing chamber, said second movable wall operably engages said second lever and moves it toward its maximum loading position; yieldable biasing means normally nrging said second movable wall out of operable engagement with said spring engag ing means; and third fluid passage means, including a time delay flow restriction, connecting said timing chamber to an area normally at a relatively low pressure incapable of moving said second movable wall in opposition to said yieldable biasing means and supplied with a higher pressure only when the main valve is operated to its open position so that, upon initial opera-tion, said exhaust valve responds to a pressure corresponding to the minimum loading condition and maintains pressure at the outlet substantially constant at that pressure and, after a time delay due to said restriction, said second movable wall moves said second lever to its maximum loading position and said exhaust valve responds only to a substantially greater pressure and maintains the outlet pressure substantially constant at said greater pressure.

16. A pressure responsive exhaust valve comprising: a body having an operating chamber and a timing chamber therein, said chambers having first and second movable walls, respectively, each of said movable walls having one side exposed to fluid pressure in the corresponding chamber and the other side exposed to an area of low pressure, said body having a valve port in said operating chamber; a valve closure member operable by said first movable wall to control fluid flow through said port, fluid pressure in said operating chamber urging said first movable wall in a direction to open said closure member; loading spring means operably engaging said first movable wall to urge it to a position to close said exhaust valve closure means; lever means mounted on said body and having a portion movable with respect thereto; spring engaging means operably engaging said loading spring means and being movable to vary the loading on said first movable wall, said spring engaging means being operably associated with said lever means and positioned according to the position of said movable portion of said lever means, said spring engaging means being operably engageable by said first movable wall; adjustment means operably assoicated with said lever means and manually movable to select the limits of movement of said spring engaging means and thereby the maximum and minimum loading conditions of said first movable wall; yieldable biasing means normally urging said second movable wall out of operable engagement with said spring engaging means; and a restricted fluid passage adapted to connect said timing chamber to an area supplied with fluid pressure whenever pressure is applied to said operating chamber so that upon initial application of pressure to said operating chamber, the closure means opens in response to a first pressure on said first movable wall effective to overcome the loading thereon corresponding to said minimum loading condition, and, after a time delay determined by the size of the restriction in said restricted passage, the pressure in said timing chamber overcomes said yieldable biasing means and moves said second movable wall into operative engagement with said spring engaging means and thereby moves said spring engaging means to its maximum loading position so that said exhaust valve opens only in response to a second relatively greater pressure.

17. The exhaust valve of claim 16 wherein there is associated with said second movable wall, means selectively operable to render said second movable wall inoperative to additionally load said first movable wall after said time delay so that the valve operates continuously at said first pressure.

No references cited.

M. CARY NELSON, Primary Examiner.

10 R. J. MILLER, Assistant Examiner.

Claims (1)

1. A PRESSURE RESPONSIVE EXHAUST VALVE FOR USE IN CONTROLLING A MAIN VALVE OF THE TYPE HAVING A MAIN CLOSURE MEMBER BIASED TO A CLOSED POSITION, A CONTROL CHAMBER INCLUDING A MOVABLE WALL OPERABLY CONNECTED TO THE MAIN CLOSURE MEMBER AND RESPONSIVE TO PRESSURE IN THE CONTROL CHAMBER TO OPEN THE CLOSURE MEMBER, AND CONTROL VALVE MEANS OPERABLE TO A FIRST POSITION TO CONNECT THE CONTROL CHAMBER TO PRESSURE AT THE INLET OF THE MAIN VALVE TO CAUSE OPENING OF THE MAIN CLOSURE MEMBER, AND OPERABLE TO A SECOND POSITION TO CONNECT THE CONTROL CHAMBER TO THE OUTLET OF THE MAIN VALVE TO CAUSE CLOSURE OF THE MAIN CLOSURE MEMBER, THE EXHAUST VALVE COMPRISING: A BODY HAVING A VOID THEREIN; A PAIR OF SPACED, GENERALLY PARALLEL DIAPHRAGMS DISPOSED IN SAID VOID AND DIVIDING IT INTO AN OPERATING CHAMBER BETWEEN THE FIRST OF SAID DIAPHRAGMS AND SAID BODY AND A TIMING CHAMBER BETWEEN THE SECOND OF SAID DIAPHRAGMS AND SAID BODY, AND A CENTRAL CHAMBER INTERMEDIATE SAID DIAPHRAGMS; FIRST FLUID PASSAGE MEANS INCLUDING A FLOW RESTRICTION AND CONNECTING SAID CENTRAL CHAMBER TO ATMOSPHERE; SECOND FLUID PASSAGE MEANS ADAPTED TO CONNECT SAID OPERATING CHAMBER TO THE OUTLET OF THE MAIN VALVE; THIRD FLUID PASSAGE MEANS ADAPTED TO CONNECT SAID OPERATING CHAMBER TO THE CONTROL CHAMBER; AN EXHAUST VALVE CLOSURE MEANS COOPERABLE WITH SAID THIRD FLUID PASSAGE TO CONTROL FLUID FLOW THERETHROUTH, SAID CLOSURE MEMBER BEING OPERABLY ENGAGED BY SAID FIRST DIAPHRAGM AND NORMALLY URGED THEREBY TO A POSITION TO CLOSE SAID THIRD PASSAGES MEANS, SAID FIRST DIAPHRAGM BEING RESPONSIVE TO FLUID PRESSURE IN SAID OPERATING CHAMBER FOR MOVEMENT TOWARD SAID CENTRAL CHAMBER TO ALLOW SAID CLOSURE MEMBER TO OPEN SAID THIRD PASSAGE MEANS; A PAIR OF SPACED GENERALLY PARALLEL LEVER MEMBER CANTILEVERED ON SAID BODY IN SAID CENTRAL CHAMBER AND EXTENDING GENERALLY PARALLEL TO SAID DIAPHRAGMS, SAID LEVELS HAVING A PAIR OF ALIGNED APERTURES THERETHROUGH, EACH OF SAID LEVERS HAVING A CALIBRATION TAB EXTENDING THEREFROM AT AN ACUTE ANGLE TO SAID LEVERS; A FIRST ADJUSTMENT MEMBER THREADED INTO SAID BODY AND EXTENDING INTO SAID CENTRAL CHAMBER GENERALLY PARALLEL TO SAID LEVERS AND ENGAGING THE CALIBRATION TAB ON THE FIRST OF SAID LEVERS SO THAT SAID ADJUSTMENT MEMBER MAY BE SELECTIVELY MANIPULATED TO DEFLECT SAID FIRST LEVER TOWARD OR AWAY FROM THE SECOND OF SAID LEVERS; A SECOND ADJUSTMENT MEMBER, SIMILAR TO SAID FIRST ADJUSTMENT MEMBER AND ENGAGING THE CALIBRATION TAB ON SAID SECOND LEVER SO THAT SAID SECOND ADJUSTMENT MEMBER MAY BE SELECTIVELY MANIPULATED TO DEFLECT SAID SECOND LEVER TOWARD OR AWAY FROM SAID FIRST LEVER; A GENERALLY CUP-SHAPED MEMBER HAVING AN ANNULAR FLANGE AROUND ITS EXTERIOR, SAID MEMBER BEING ENTRAPPED BETWEEN SAID LEVER MEMBERS WITH THE CLOSED END OF THE CUP EXTENDING THROUGH SAID SECOND LEVER TOWARD SAID SECOND DIAPHRAGM; A FIRST LOADING SPRING DISPOSED BETWEEN SAID CUP-SHAPED MEMBER AND SAID FIRST DIAPHRAGM AND URGING SAID FIRST DIAPHRAGM TO A POSITION TO CLOSE SAID CLOSURE MEMBER WITH RESPECT TO SAID THIRD PASSAGE AND URGING SAID CUP-SHAPED MEMBER TOWARD A POSITION WHEREIN THE FLANGE THEREON ENGAGES SAID SECOND LEVER; A SECOND, SUBSTANTIALLY LIGHTER SPRING INTERMEDIATE SAID CUP-SHAPED MEMBER AND SAID SECOND DIAPHRAGM AND NORMALLY URGING SAID SECOND DIAPHRAGM AWAY FROM THE CUP-

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