US3791398A

US3791398A - Valve construction and control system utilizing the same

Info

Publication number: US3791398A
Application number: US00304361A
Authority: US
Inventors: A Vickery
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1972-11-06
Filing date: 1972-11-06
Publication date: 1974-02-12
Anticipated expiration: 1991-02-12

Abstract

A valve construction having a housing provided with a pair of chambers therein. The housing has first and second valve seats respectively leading to one of the chambers. A valve member is movably carried by the housing and has a pair of valve means for respectively cooperating with the first and second valve seats in an alternate manner. The valve member has a piston part thereof slideably disposed in the other of the chambers and cooperating therewith as a piston in a cylinder whereby fluid pressure in the chamber is adapted to act on one side of the piston part and tend to move the valve member from a position thereof closing one of the valve seats to a position thereof closing the other of the valve seats.

Description

United States ?atent n91 Vickery VALVE CONSTRUCTION AND CONTROL SYSTEM UTILIZING THE SAME [75] Inventor: Arthur V. Vickery, Manzville, Tenn.

[73] Assignee: Robertshaw Controls Company,

Richmond, Va.

22 Filed: Nov. 6, 1972 21 App]. No.: 304,361

[52] U.S. Cl 137/625.66, 137/625.2, 137/102 [51] Int. Cl. Fl6k 17/00 [58] Field of Search... 137/102, 458, 462, 463, 464, 137/467, 625.2, 625.6, 625.66, 625.27;

[451 Feb. 12, 1974 Primary ExaminerWilliam R. Cline Assistant ExaminerGeorge L. Walton Attorney, Agent, or FirmCandor, Candor & Tassone [57] ABSTRACT A valve construction having a housing provided with a pair of chambers therein. The housing hasfirst and second valve seats respectively leading to one of the chambers. A valve member is movably carried by the housing and has a pair of valve means for respectively cooperating with the first and second valve seats in an alternate manner. The valve member has a piston part thereof slideably disposed in the other of the chambers and cooperating therewith as a piston in a cylinder whereby fluid pressure in the chamber is adapted to act on one side of the piston part and tend to move the valve member from a position thereof closing one of the valve seats to a position thereof closing the other of the valve seats.

12 Claims, 9 Drawing Figures PATENTEBFEB 1 2 I974 v sun-:11 0F 3 PAIENIEDFEBI 2 3.791.398 sum 2 OF 3 FlGg6 PAKNTED FEB I 21874 SHEET 3 OF 3 VALVE CONSTRUCTION AND CONTROL SYSTEM UTILIZING THE SAME This invention relates to an improved valve construction and to a control system utilizing such a valve construction or the like.

It is well known that valve constructions have been provided wherein a supply pressure fluid is interconnected to one valve seat of the valve construction that leads to a chamber thereof which is interconnected to a pressure operated, controlled device. Such chamber is also interconnected by a valve seat to an exhaust passage whereby a valve member having a portion thereof disposed in the chamber is adapted to open and close the valve seats in an alternate manner to either interconnect the chamber to the fluid pressure source or to the exhaust passage for the purpose of controlling the controlled device. In addition, a pressure operated pilot sensing device is interconnected to a chamber of the valve construction to act on the valve member in such a manner that there is a loss of pressure at the safety device if the same senses that an unsafe condition exists in connection with the controlled device, the loss of pressure causing the valve member to be shifted by pressure unbalance and a spring acting on the valve member to a position thereof which interconnects the control pressure chamber to the exhaust passage so that the controlled device will be placed in a shutdown condition thereof. Thereafter, in order to reset the device, the valve member must be manually moved to a position thereof that will close off the valve seat that leads to the exhaust passage and open the valve seat that interconnects the fluid pressure source to the chamber so that the controlled device can again be operated if the pilot sensing device senses a safe condition.

Accordingly, it is a feature of this invention to provide an improved valve construction of the above type.

In particular, one embodiment of this invention provides a valve construction having a housing means provided with a pair of chambers therein. The housing means has first and second valve seats leading respectively to one of the chambers. A valve member is mov ably carried by the housing means and has a pair of valve means for respectively cooperating with the first and second valve seats in an alternate manner. The valve member has a piston part thereof slideably disposed in the other of the chambers and cooperating therewith as a piston in a cylinder whereby fluid pressure in the chamber is adapted to act on one side of the piston part and tend to move the valve member from a position thereof closing one of the valve seats to a position thereof closing the other of the valve seats. A passage defining means interconnects the other chamber to the one chamber of the housing means with such passage defining means having a restriction therein. The piston part comprises an annular member telescopically disposed about a stem of the valve member and is held against a stop means thereof by a spring means carried by the housing means and acting on the other side of the piston part in opposition to the fluid pressure in the other chamber.

Accordingly, it is an object of this invention to provide an improved valve construction having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide a control system utilizing such a valve construction or the like.

Other objects, uses and advantageous of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIG. 1 is a side view of one embodiment of the im proved valve construction of this invention.

FIG. 2 is a cross-sectional view taken on line 2--2 of FIG. 1 and schematically illustrates a control system for the valve construction.

FIG. 3 is a view similar to FIG. 2 and illustrates the valve construction with the valve member thereof in another operating position.

FIG. 4 is a top view of the valve construction of FIG. 1.

FIG. 5 is a bottom view of the valve construction of FIG. 1.

FIG. 6 is a view similar to FIG. 2 and illustrates another embodiment of valve construction of this invention.

FIG. 7 is a view similar to FIG. 2 and illustrates still another embodiment of this invention.

FIG. 8 is a side view of the valve construction of FIG. 7.

FIG. 9 is a bottom view of the valve construction of FIG. 7.

While the various features of this invention are hereinafter described and illustrated as being particularly adapted to provide a valve construction for a particular control system, it is to be understood that the various features of this invention can be utilized singly or in any 7 combination thereof to provide a valve construction for other systems as desired.

Therefore, this invention is not to be limited to only the embodiment illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIGS. 1 and 2, the improved valve construction of this invention is generally indicated by the reference numeral 10 and is illustrated in FIG. 2 as being utilized in a control system that is generally indicated by the reference numeral 11 and comprising a source 12 of pressure fluid adapted to be interconnected by a conduit means 13 to a supply port 14 of the housing means 15 of the valve construction 10. A pressure operated, controlled device 16 is adapted to be interconnected by a conduit means 17 to a control pressure port 18 of the valve construction 10 for a purpose hereinafter described. Also, a pressure operated, pilot safety sensing device 19 is adapted to be interconnected by a conduit 20 to a pilot port 21 of the valve construction 10.

The valve construction 10 operates in a manner hereinafter described to interconnect the supply pressure source 12 to the controlled device 16 as long as the sensing device 19 senses a safe condition, such as a safe operating condition caused by the operating controlled device 16. However, when the device 19 senses an unsafe condition, the same interconnects the conduit 20 to the atmosphere to cause the valve construction 10, in a manner hereinafter described, to disconnect the supply pressure source 12 from the controlled device 16 and interconnect the controlled device 16 to the atmopshere to dump the pressure fluid thereof so that the controlled device 16 will return to a shut down and inoperative condition thereof. Thereafter, the valve construction cannot interconnect the pressure source 12 to the controlled device 16 until a valve member 22 of the valve construction it) is manually moved by a handle part 23 thereof to the position illustrated in FIG. 2 and be held in such position until the safety device 19 senses a safe condition to thereafter maintain the valve construction in the operating condition of FIG. 2.

The housing means of the valve construction 10 is formed from three

housing parts

24, 25 and 26 disposed in stacked aligned relation and suitably bolted together by bolt means 27. Sealing gasket means 28 and 29 are respectively disposed between the housing means 24, 25 and 26 to seal the same together as illustrated.

The

housing parts

24, 25 and 26 cooperate together to define a pair of

chambers

30 and 31 therein and being interconnected by an intermediate, stepped passage or bore means 32. However, the valve member 22 has a stem part 33 thereof that extends through the bore means 32 in close sliding relation thereto so as to be guided by the bore means 32 in its up and down movement between the operating positions of FIGS. 2 and 3.

The

housing members

24 and 25 respectively have valve seats or

ports

34 and 35 that lead to the chamber 30 in opposed aligned relation with the valve seat 34 interconnecting with a passage 36 passing through the housing part 24 to the atmosphere whereby the valve seat comprises an exhaust valve seat. The valve seat 35 interconnects with the bore 32 which is transversely intersected by the supply pressure port 14 whereby the valve seat 35 becomes a supply pressure valve seat for the valve construction 10.

The valve member 22 has an enlarged cylindrical part 37 at the upper end of the stem 33 and at the lower end of an upper stem 38 that projects outward through the exhaust port 36 and carries the handle member 23 thereon. The cylindrical part 37 of the valve member 22 is so constructed and arranged that the same defines opposed valve means 39 and 40 which are respectively adapted to open and close the

valve seats

34 and 35 in an alternate manner, i.e., when the valve means 39 is closing the exhaust valve seat 34, the valve means 40 has opened the supply pressure valve seat 35 and when the valve means 40 is closing the supply pressure valve seat 35, the valve means 39 has opened the exhaust valve seat 34. If desired, the valve means 33 and 40 of the part 37 of the valve member 22 can comprise the opposed annular shoulders of the intermediate valve member part 37 with such shoulders respectively having

annular grooves

41 and 42 formed therein and respectively receiving resilient O-

rings

43 and 44 which respectively seal against opposed

flat surfaces

45 and 46 of the

housing parts

24 and 25 outboard of the

respective valve seats

34 and 35 to seal close the same as illustrated respectively in FIGS. 2 and 3.

The control pressure port R8 of the housing means 10 is interconnected by a cross passage 47 to the chamber 30 at the surface 46 of the housing part 25, but at a point outboard of where the valve means 40 of the valve member 37 seals closed against the surface 46 whereby the chamber 30 is at all times interconnected by the passage 47 to the control pressure port 18 regardless of the position of the valve member 22.

The lower stem 33 of the valve member 22 is substantially cylindrical and carries an annular member or piston part 48 thereon which acts as a piston member in the chamber 31 as the piston member 48 is slideably disposed therein. The piston member 48 is interconnected to the stem 33 in a manner hereinafter described to substantially move in unison therewith in response to fluid pressure in the chamber 31 that acts against the lower side 49 of the piston part 48.

The lower end of the stem 33 of the valve member 22 has an annular groove 50 formed therein and receiving an annular sealing member 51 therein which is adapted to seal against the inside peripheral cylindrical surface 52 of the piston part 48 when the same is disposed against a stop means 53 of the stem 22 that comprises a split ring disposed in an annular groove 54 formed in the stem 33 as illustrated. Thus, no fluid pressure on either

side

49 or 55 of the piston part 48 can pass between the piston part 48 because of the sealing member 51.

Likewise, the piston part 48 has an outwardly facing annular groove 56 formed therein intermediate the upper and

lower sides

55 and 49 thereof with the same receiving an annular O-ring 57 that is adapted to seal against the internal peripheral surface 58 of the housing means 15 that defines the chamber 31 thereof while still permitting sliding movement of the piston part 48 in the chamber 31.

In order to maintain the annular piston part 48 against the stop means 53 of the valve member 22, a compression spring 59 is disposed in the chamber 31 on the side 55 of the pistonpart 48 whereby one end 60 of the spring 59 bears against the side 55 of the piston part 48 and the other end 61 of the spring 59 bears against a shoulder means 62 of the housing part 25 that is disposed adjacent the bore 32 thereof. In this manner, the force of the compression spring 59 not only tends to maintain the piston part 48 against the stop means 53 of the valve member 22 in a manner illustrated in FIGS. 2 and 3, but also the force of the compression spring 59 tends to drive the valve member 22 downwardly from the position illustrated in FIG. 2 to the position illustrated in FIG. 3 to maintain the same in the position illustrated in FIG. 3 wherein the valve means 40 is closing the pressure supply valve seat 35 and the chamber 30 is being exhausted through the open exhaust valve seat 34.

The pilot port 21 is interconnected by a passage means 63 formed in the housing part 26 to the chamber 31 below the lower side 49 of the piston part 48 to always be in communication with the chamber 31 below the piston part 48 in the manner illustrated in FIGS. 2 and 3.

The upper stem 38 of the valve member 22 has an annular groove 64 formed therein and receives the inner peripheral means 65 of a dome-shaped flexible valve member 66 that has its outer peripheral portion 67 bearing against the upper surface 68 of the upper housing part 24 so as to surround and close the exhaust passage 36 except when fluid pressure is passing out through the exhaust passage 36 wherein the same forces itself under the peripheral edge 67 of the exhaust valve member 66 to pass to the atmosphere.

The housing means 25 and 26 of the valve construction 10 are provided with a passage 68 that leads from the pilot port 21 to the control pressure port 18 and, thus, interconnects the chamber 30 with the part of the chamber 31 that is disposed below side 49 of the piston part 48 of the valve member 22, the passage 68 having an orifice cup 69 disposed therein to provide a restriction means in the passage means 68 for a purpose hereinafter described.

Therefore, it can be seen that the valve construction 11) of this invention can be formed from a relatively few parts in a relatively simple manner to provide the valve construction that will operate in the control system 11 in a manner now to be described.

When the valve construction 10 is in the position illustrated in FIG. 2 where the valve member 22 is in its up position so that the valve means 39 closes the exhaust valve means 34 while the main supply valve seat 35 is open, the supply pressure from the source 12 is interconnected to the chamber 30 and, thus, through the port 18 to the controlled device 16 to maintain the same in an on condition thereof. This fluid pressure in the chamber 30 is also interconnected by passage 68 through the restriction 69 thereof to the lower part of the chamber 31 and if the device 19 is sensing a safe condition so as to close off the conduit 20 from the atmosphere, pressure builds up in the chamber 31 below the piston part 48 to the same pressure as the pressure of the control fluid in the chamber 30. Thus, this pressure fluid in the lower part of the chamber 31 acts on the underside 49 of the piston means 418 on the end 33 of the valve member 22 to maintain the valve member 22 in its up position as illustrated in FIG. 2 in opposition to the force of the compression spring 59.

However, in the event an unsafe condition begins to exist, the pilot sensing device 19 exhausts the pilot line pressure in the chamber 31 through the conduit 20 to the atmosphere whereby once the pressure in the lower part of the chamber 31 is thus lost, the spring 59 biases the piston part 48 and, thus, the valve member 22 to the down position illustrated in FIG. 3 where the valve member 22 opens the exhaust port 34 and closes off the supply pressure at the main valve seat 35. The supply pressure 12 acting on the side 55 of the piston part 48 tends to assist the compression spring 59 in maintaining the valve member 22 in the down position illustrated in FIG. 3 whereby the fluid pressure at the controlled device 16 and in the chamber is exhausted out through the open exhaust valve seat 34 and passes beneath the edge 67 of the exhaust valve 66 to the atmosphere so that the device 16 is now rendered inoperative or is placed in its shut down position.

When the device 19 indicates that a safe condition exists and closes the conduit 20 from the atmosphere, the valve construction 10 must be manually operated by an operator pulling upwardly on the handle part 23 of the valve member 22 to move the valve member 22 upwardly from the position illustrated in FIG. 3 back to the position illustrated in FIG. 2 in opposition to the force of the compression spring 59 and the supply pressure acting on the side 55 of the piston part 48. The valve member 22 must be manually maintained in this up position where the supply port is open and the exhaust port 34 is closed until the pressure again builds up in the control pressure chamber 30 and, thus, builds up in the lower part of the chamber 31 through the restriction means 69 in the passage 68 in the manner previously described to maintain the valve member 22 in its up position. Thus, the valve member 22 will remain in the up position illustrated in FIG. 2 until the pilot pressure fails in chamber 31 in the manner previously described or the handle part 23 is manually forced downwardly to exhaust the control line 17 through the exhaust valve seat 34. During this manual exhausting of the valve construction 10, the pressure in the chamber 31 below the piston part 48 and in the conduit 20 to the safety device 19 is back bleeded through the restrictor 69 into the chamber 30 and out through the opened exhaust port 34 whereby the valve member 22 will close off the supply valve seat 35 and will remain in its down position illustrated in FIG. 3 until again manually moved upwardly to the position illustrated in FIG. 2 in the manner previously described.

Another valve construction of this invention is generally indicated by the reference numeral 10A in FIG. 6 and parts thereof similar to the valve construction 10 previously described are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIG. 6, the valve construction 10A is substantially identical to the valve construction 10 previously described except that the passage 68 which interconnects the pilot port 21 to the control port 18 has been removed from the valve construction 10A and is now provided through the valve member 22A thereof.

In particular, it can be seen in FIG. 6 that a passage means 70 is formed upwardly through the stem 33A of the valve member 22A to the enlarged part 37A thereof wherein the same is joined by a cross passage 71 to the chamber 30A intermediate the valve means 39A and 411A thereof. The passage 70 can have the orifice cup 69A disposed at the lower end thereof as illustrated whereby it can be seen that the lower part of thechamber 31A is interconnected by the passage means 70, 71 to the chamber 30A at all times regardless of the position of the valve member 22A. Thus, the operation of the valve member 10A is identical to the operation of the valve construction 10 previously described except that the passage that always interconnects the

chambers

30 and 31 together is in the valve member 22 rather than in the housing means 24, 25 and 26.

It can be seen that the valve constructions 10 and 10A can be formed from rod stock with the only difference being in the method of routing the control pressure through the restrictor to the pilot chamber. However, the valve construction 10A is somewhat simpler than the valve construction 10 because a simpler machine of the housing parts thereof can be provided since the routing of the control pressure through the restrictor to the pilot chamber is through the valve member 22A thereof.

Another valve construction of this invention is generally indicated by the reference numeral 108 in FIGS. 7, 8 and 9 and parts thereof similar to the valve constructions 10 and 10A previously described are indicated by like reference numerals followed by the reference letter B.

It can be seen that the valve construction 1013 of FIGS. 7-9 is substantially the same as the valve con struction 10A of FIG. 6 previously described wherein the routing of the control pressure through the restrictor to the pilot chamber is through the valve member 2213 thereof and the only difference between the valve construction 10A and 10B is that the

body housing parts

24B, 25B and 26B are forgings rather than rod stock assemblies.

Therefore, it can be seen that this invention not only provides an improved valve construction, but also this invention provides a control system utilizing such a valve construction or the like.

While the form of the invention now preferred has been disclosed and described as required by the patent statutes, it is to be understood that other forms can be utilized and all come within the scope of the appended claims.

What is claimed is:

1. A valve construction comprising a housing means having a pair of chambers therein, said housing means having first and second valve seats leading to one of said chambers, said housing having an inlet means leading to one of said valve seats and having an outlet means leading from said one chamber intermediate said valve seats, a valve member movably carried by said housing means and having a pair of valve means for respectively cooperating with said first and second valve seats in an alternate manner, said valve member having a piston part thereof slidably disposed in the other of said chambers and cooperating therewith as a piston in a cylinder whereby fluid pressure in said other chamber is adapted to act on one side of said piston part and tend to move said valve member from a position thereof closing one of said valve seats to a position thereof closing the other of said valve seats, said piston part comprising an annular member telescoped onto said valve member and being slidable thereon, said valve member carrying a stop means that limits sliding movement of said annular member on said valve member in one direction, and a spring means being carried by said housing means and acting on said annular member in a direction to tend to hold said annular member against said stop means so that said piston part and said valve member tend to move in unison, said spring means also tending to move said valve member in said one direction that would be in opposition to said fluid pressure in said one chamber.

2. A valve construction as set forth in claim 1 wherein passage defining means interconnects said other chamber to said one chamber.

3. A valve construction as set forth in claim 2 wherein a restriction means is disposed in said passage defining means.

4. A valve construction as set forth in claim 3 wherein said passage defining means is provided in said housing means.

5. A valve construction as set forth in claim 3 wherein said passage defining means is provided in said valve member.

6. A valve construction as set forth in claim 1 wherein said annular member has an annular groove in its outer periphery, and an annular sealing member disposed in said groove.

7. In a control system having a fluid source, a fluid operated controlled device, and a fluid operated sensing device, the improvement comprising a valve construction having a housing means provided with a pair of chambers therein, said housing means having first and second valve seats leading to one of said chambers, means interconnecting said source to one of said valve seats, means interconnecting said controlled device to said one chamber, intermediate said valve seats, a valve member movably carried by said housing means and having a pair of valve means for respectively cooperating with said first and second valve seats in an alternate manner, said valve member having a piston part thereof slidably disposed in the other of said chambers and cooperating therewith as a piston in a cylinder whereby fluid pressure in said other chamber is adapted to act on one side of said piston part and tend to move said valve member from a position thereof closing one of said valve seats to a position thereof closing the other of said valve seats, and means interconnecting said sensing device to said other chamber on said one side of said piston part, said piston part comprising an annular member telescoped onto said valve member and being slidable thereon, said valve member carrying a stop means that limits sliding movement of said annular member on said valve member in one direction, and a spring means being carried by said housing means and acting on said annular member in a direction to tend to hold said annular member against said stop means so that said piston part and said valve member tend to move in unison, said spring means also tending to move said valve member in said one direction that would be in opposition to said fluid pressure in said one chamber.

8. In a control system as set forth in claim 7, the further improvement wherein passage defining means interconnects said other chamber to said one chamber.

9. In a control system as set forth in claim 8, the further improvement wherein a restriction means is disposed in said passage defining means.

10. In a control system as set forth in claim 9, the further improvement wherein said passage defining means is provided in said housing means.

11. In a control system as set forth in claim 9, the further improvement wherein said passage defining means is provided in said valve member.

12. In a control system as set forth in claim 7, the further improvement wherein said annular member has an annular groove in its outer periphery, and an annular sealing member disposed in said groove.