Background of the Invention [0002] US Patent 6,229, 546, the entire disclosure of which is hereby incorporated by reference, discloses fluid control systems including a plurality of surface mounted components mounted on a base or substrate. One of the fluid control systems of said published application is shown in Fig. 1 herein. In this system, fluid is directed by the substrate between various ones of the surface mounted components, which control the fluid flow.

[0003] One type of component that can used in this type of system is a pressure regulator. One such regulator is shown in US Patent No. 6,047, 728, the entire disclosure of which is hereby incorporated by reference. The regulator shown in Fig.

1 of said patent is used to maintain a steady fluid pressure downstream of the regulator. The downstream pressure is present at the fluid outlet D and acts on the underside of the bellows face plate 16, against the biasing force of the spring 7.

[0004] For example, if the downstream pressure increases, the fluid pressure on the bellows face plate increases, moving the plate upward against the biasing force of the spring. This movement tends to move a poppet 22 closer to a valve seat 20, thus closing the orifice between the fluid inlet A and the fluid outlet D. This closing of the orifice reduces fluid flow and thus reduces the pressure at the fluid outlet D, to counteract the increased pressure caused by the downstream event.

[0005] Likewise, if the downstream pressure decreases, the fluid pressure on the bellows face plate decreases, allowing the plate to move downward under the biasing force of the spring. This movement tends to move the poppet 22 farther from the valve seat 20, thus opening the orifice between the fluid inlet A and the fluid outlet D.

This opening of the orifice increases fluid flow to counteract the decreased pressure caused by the downstream event.

[0006] The regulator shown in US Patent No. 6,047, 728 is adjustable, by turning a knob, to vary the preload on the spring and thus vary the nominal downstream pressure. Such regulators may be surface mount as described above, or may be connected in the fluid system by other means, such as NPT pipe ports or with welded fittings. Typically the fluid system in which such a regulator is used also includes a pressure gauge in line with the regulator, so that as the regulator is adjusted, the operator can see the resulting changes in pressure. In some systems, the use of a separate pressure gauge is undesirable since it occupies space in a limited area and it would need to be suitable for ultra high purity gas applications : Summary of the Invention [0007] The invention relates to a fluid flow device, such as a pressure regulator.

The device includes a transducer, which may be a pressure sensor. The transducer has a wetted portion and a non-wetted portion. The transducer is installed in the device so that the wetted portion is contacted by the fluid in the device. The transducer outputs a signal that is indicative of pressure in the device. Preferably the signal is directed to an onboard readout but alternatively may be directed to a connector or a transmitter.

Brief Description of the Drawings [0008] The foregoing and other features will become apparent to one skilled in the art upon consideration of the following description with reference to the accompanying drawings, in which: [0009] Fig. 1 is a perspective view of a fluid control system including a pressure regulator in accordance with a first embodiment of the invention, the regulator including a rigid bellows face plate; [0010] Fig. 2 is a longitudinal cross-sectional view of the regulator of Fig. 1 ; [0011] Fig. 3 is an enlarged sectional view of a portion of the regulator of Fig. 2; [0012] Fig. 4 is a perspective view of the regulator of Fig. 2 ; [0013] Fig. 5 is a schematic sectional view of a portion of a regulator in accordance with a second embodiment of the invention, the regulator including a flexible diaphragm; [0014] Fig. 6 is a schematic elevational view of a regulator in accordance with a third embodiment of the invention, the regulator having a hard-wired readout capability; [0015] Fig. 7 is a schematic elevational view of a regulator in accordance with a fourth embodiment of the invention, the regulator having a wireless readout capability; and [0016] Fig. 8 is a view similar to Fig. 2 of a back pressure regulator in accordance with a fifth embodiment of the invention.

Description of Embodiments of the Invention [0017] The invention relates to a regulator with a pressure transducer.

Regulators of various types, including those shown in the drawings and described herein and others, are encompassed within the scope of the invention. As representative of the invention, Figs. 1-4 illustrate a regulator 10 in accordance with a first embodiment of the invention.

[0018] The regulator 10 includes a body 12. The body 12 is preferably cast from a metal, such as stainless steel, but may be made in a different manner or from a different material. The body 12 defines a chamber 14.

[0019] The body 12 includes a fluid inlet passage 16 that extends outward from the chamber 14 and terminates in an inlet port 18.

[0020] The inlet port 18 is connected with a fluid line shown schematically at 19.

The fluid line shown at 19 is representative of a other fluid lines to which the regulator 10 could be connected, each one of such structures defining a passage through which fluid can flow, to be controlled or regulated by the regulator 10. Thus, a fluid line could be a pipe or tube, or could be some other component or portion of a fluid system or device that has fluid flowing through it.

[0021] The inlet passage 16 is centered on a longitudinal central axis 20 of the regulator 10. The inlet passage 16 could be located elsewhere in the valve body 12.

The body 12 also includes a fluid outlet passage 22 that extends outward from the chamber 14 and terminates in an outlet port 24. the outlet port 24 is connected with the fluid line 19. The chamber 14 interconnects the fluid inlet 18 and the fluid outlet 24.

[0022] The body 12 includes a valve seat 30 that defines an orifice 32 in the fluid inlet passage 16. A valve member in the form of a poppet 34, described below in more detail, is movable relative to the valve seat 30 to control the size of the orifice 32 and, thereby, to control fluid flow through the regulator 10. The body 12 also has a mounting portion 36 for mounting of the regulator 10 on other parts of a fluid flow system, such as the system shown in Fig. 1, so that the regulator is operative to control fluid pressure at the fluid outlet 24.

[0023] A spring housing 40 is fixed to the valve body 12. The spring housing 40 has a generally cylindrical configuration including an externally threaded lower end portion 42 and an externally threaded upper end portion 44. The lower end portion 42 is screwed into an upper end portion 46 of the valve body 10. As a result, the spring housing 40 is fixed to the valve body 12.

[0024] The inner end or upper end of the chamber 14 in the valve body 12 is sealed by a bellows assembly 50. The bellows assembly 50 includes a bellows 52 and a face plate 54. The bellows 52 is a flexible member that supports the face plate 54 on the valve body 12 for movement relative to the valve body. The bellows 52 may be made in a manner known in the art.

[0025] A washer or other type of seal 56 is disposed between the lower end portion 42 of the spring housing 40 and the outer peripheral edge of the bellows 52.

The screw engagement of the lower end portion 42 of the spring housing 40 in the valve body 12 clamps the washer 56 and the bellows 52 to the valve body 12 to seal the outer peripheral edge of the bellows.

[0026] The face plate 54 forms the lower end portion of the bellows assembly 50.

The face plate 54 is a circular plate that is rigid enough so that it does not flex significantly under the pressures encountered in the regulator 10. The face plate 54 has opposite inner and outer major side surfaces 60 and 62. The outer peripheral portion of the face plate 54 is fixed to the bellows 52 in a known manner so that the face plate moves axially as the bellows expands and contracts.

[0027] The face plate 54 acts as a movable wall that at least partially closes the chamber 14. The volume or chamber of the body 12 that is below the bellows 52 is the wetted or pressurized portion of the regulator; the remainder of the regulator, within the body, is the non-wetted portion. Thus, the inner major side surface 60 of the face plate 54 is the non-wetted side of the face plate, and the outer major side surface 62 is the wetted side of the face plate.

[0028] An opening 66 is formed in the face plate 54. In the illustrated embodiment, the opening 66 is circular in configuration and is centered on the axis 20. The opening 66 could have a different configuration or size and could be located elsewhere on the face plate 54. The opening 66 enables fluid communication between the wetted and non-wetted sides 62 and 60 of the face plate 54. As a result, an area (the area of the opening 66) on the non-wetted side of the face plate 54 is actually wetted, that is, is contacted by the fluid in the device.

[0029] A poppet support assembly 70 connects the poppet 34 to the face plate 54 for movement with the face plate. The poppet support assembly 70 includes a support ring 72 and a linear guidance wafer 74. The support ring 72 and the guidance wafer 74 may be constructed in a manner known in the art.

[0030] The support ring 72 engages the face plate 54 and has a central hub portion to which an upper end portion of the poppet 34 is fixed. The support ring 72 is supported by the linear guidance wafer 74 on the valve body 12. The support ring 12 and the guidance wafer 74 are both slotted or otherwise perforated to enable fluid flow through them.

[0031] The poppet support assembly 70 transmits axial force between the bellows face plate 54 and the poppet 34. Thus, the poppet 34 is connected for movement with the face plate 54.

[0032] The lower end portion of the poppet 34 supports a seal or movable valve member 76 that is disposed in the fluid inlet passage 16. The seal 76 is engageable with the valve seat 30 to close the orifice 32 upon sufficient upward movement of the poppet 34 and the face plate 54.

[0033] A cup 78 is disposed in the valve body 12. The cup 78 is fixed to the inner side surface 60 of the bellows face plate 54. The cup 78 has a cylindrical side wall 80 that engages the inner side surface 60 of the bellows face plate 54. The cup 78 has an annular flange 82 at one end of the side wall 80. The flange 82 is engageable with the washer 56. A thrust washer 84 is disposed above the cup 78, in engagement with the flange 82 of the cup.

[0034] A knob 86 is connected with the spring housing 40. The knob 86 has an inverted cup shaped configuration including a cylindrical side wall and a radially extending end wall 90. The side wall 88 of the knob 86 is internally threaded and is screwed on the upper end portion 44 of the spring housing 40. As a result, when the knob 86 is turned, it moves axially up or down relative to the spring housing 40 and, thus, relative to the valve body 12. The end wall 90 of the knob 86 has a circular window 92 that is centered on the axis 20.

[0035] A spring cap 94 is disposed in the upper end portion 44 of the spring housing 40. The spring cap 94 has a cylindrical side wall 96 that is slidably received inside the upper end portion 44 of the spring housing 40. The spring cap 94 has a circular, radially extending end wall 98 that is partially visible from the exterior of the regulator 10 through the window 92 in the knob end wall 90. The end wall 98 of the spring cap 94 has an annular shoulder 100 that engages the inside of the end wall 90 of the knob 86.

[0036] A compression spring 102 is also located in the spring housing 40. An upper end portion 104 of the spring seats 102 against the spring cap 94. The threaded engagement of the knob 86 on the spring housing 40 blocks axial movement of the spring cap 94 in a direction away from the valve body 12 under the influence of the spring 102. A lower end portion 106 of the spring 102 is seated on the thrust washer 84. The spring 102 is compressed between the thrust washer 84 and the spring cap 94 and biases them apart from each other. The biasing force of the spring 102 is transmitted to the bellows face plate 54 through the thrust washer 84 and the cup 78.

[0037] Fig. 2 shows the regulator 10 in a fully open condition in which the flange 82 of the cup 78 engages the washer 56 to set the outer end of the range of travel of the bellows face plate 54, the cup, and the thrust washer 84. The linear guidance wafer 74 is deflected slightly downward.

[0038] When the knob 86 is rotated in a first direction about the axis 20, the end wall 90 of the knob moves closer to the valve body 12. The end wall 90 of the knob 86 engages the shoulder 100 on the end wall 98 of the spring cap 94 so that the axial force of the knob is transmitted to the spring cap. The spring cap 94 moves axially inward but does not rotate because of resistance to rotation provided by its engagement with the spring 102.

[0039] The inward movement of the spring cap 94 causes the spring 102 to press with more force on the thrust washer 84. This increased force is transmitted through the thrust washer 84 to the cup 78 and to the face plate 54 of the bellows assembly 50.

As a result, more force is needed to move the face plate 54 upward against the bias of the spring 102. This can produce an increased fluid pressure downstream of the regulator 10.

[0040] When the knob 86 is rotated in a second direction opposite the first direction, the end wall 90 of the knob moves away from the valve body 12. The compressive force on the spring 102 is lessened and the spring presses with less force on the thrust washer 84. This decrease in force is transmitted through the thrust washer 84 to the cup 78 and to the face plate 54 of the bellows assembly 50. This can produce a decreased fluid pressure downstream of the regulator 10.

[0041] The regulator 10 is operative automatically to adjust (balance) for changes in pressure, to keep a steady downstream pressure. If the fluid pressure downstream of the regulator 10 changes, that change is present in the fluid outlet 24 and, thus, in the valve chamber 14. The change in fluid pressure is present on the face plate 54, because of the presence of the openings in the guidance wafer 74 and the support ring 72.

[0042] Increased fluid pressure on the face plate 54 causes the face plate to move upward as viewed in Fig. 2, against the bias of the spring 102. This movement of the face plate 54 causes the poppet 34 to move in a direction so that the seal 76 moves closer to the valve seat 30. This movement of the seal 76 tends to restrict fluid flow through the orifice 32. The restriction of fluid flow counteracts the increased fluid pressure downstream of the orifice 32.

[0043] Likewise, decreased fluid pressure on the face plate 54 causes the face plate to move downward as viewed in Fig. 2, under the bias of the spring 102. This movement of the face plate 54 causes the poppet 34 to move in a direction so that the seal 76 moves away from the valve seat 30. This movement of the seal 76 increases fluid flow through the orifice 32. The increased fluid flow counteracts the decreased fluid pressure downstream of the orifice 32. The range of movement of the bellows face plate 54, in a typical regulator 10 of this type, is about twenty one-thousandths of an inch (0.020").

[0044] A transducer 110 is mounted on the bellows face plate 54. The transducer 110 is for sensing fluid pressure in the chamber 14 of the regulator 10. The transducer 110 is preferably a pressure sensor.

[0045] The transducer 110 may include one or more metallic strain gauges.

Metallic strain gauges depend on dimensional changes to produce a change in resistance. A deposited or sputtered strain gauge, often called a thin film strain gauge, is the preferred type of strain gauge. This construction minimizes the effects of repeatability and hysteresis that bonded strain gauges exhibit.

[0046] These sensors exhibit a relatively small change in resistance or low output. The change of resistance is best sensed with the strain gauges arranged in an electrical circuit commonly referred to as a Wheatstone bridge configured circuit. A temperature-sensing device such as a thermistor may be added to the Wheatstone bridge circuit to provide thermal compensation for variations in the fluid or ambient temperatures.

[0047] An alternative type of transducer 110 includes a bonded semiconductor strain gauge. In this type of device, a silicon bar is bonded to a diaphragm to form a sensor with relatively high output. Making the diaphragm from a chemically inert material allows this sensor to interface with a wide variety of media.

[0048] Another type of sensor 110 that can be used is a printed strain gauge. In this type of device, a piezoresistive material such as PZT is applied to a ceramic diaphragm using thick film printing techniques. This construction can form a chemically inert, low cost sensor with relatively high output.

[0049] A semiconductor strain gauge can also be used as the pressure sensor 110, either bonded or integrated into a silicon diaphragm. In this type of device the response to applied stress is an order of magnitude larger than for a metallic strain gauge. When the crystal lattice structure of silicon is deformed by applied stress, the resistance changes. Typically, semiconductor sensors are isolated from the process stream by an additional diaphragm and a communications fluid such as silicon oil to achieve adequate chemical compatibilities.

[0050] Other types of sensors 110 that may be suitable include inductive sensors and capacitive pressure sensors. A laser ranging device or a Hall effect device may also be suitable.

[0051] The transducer 110 (Fig. 3) is sealed and secured to the inner side surface 60 (the nominally non-wetted side) of the bellows face plate 54. The transducer 110 is located on the face plate 54 so that it extends across the opening 66 in the face plate. The transducer 110 is therefore exposed to the fluid pressure in the valve chamber 14, through the openings in the guidance wafer 74, the support ring 72, and the face plate 54. As a result, the sensor 110 is operative to sense fluid pressure in the valve chamber 14. The transducer 110 may be welded or bolted to the face plate 54, or secured in another manner, although not shown in the drawings. Also, a seal, such as an 0-ring (not shown), may be used.

[0052] The transducer 110 is operative to generate an output signal over lead wires 112. The output signal is indicative of fluid pressure in the valve chamber 14.

The lead wires 112 extend upward in the regulator 10, in a direction away from the face plate 54, through the open center of the spring housing 40 to an electronics package 114. The lead wires 112 do not extend through the wetted chamber 14, but rather extend only in a non-wetted portion of the regulator 10. Alternatively, the transducer output may be transmitted wirelessly rather than via lead wires.

[0053] The electronics package 114 is mounted on an exterior portion of the regulator 10. Specifically, the electronics package 114 is mounted on the portion of the spring cap 94 that is visible through the window 92 in the knob 86. The electronics package 114 includes a digital readout 116 that is visible through the window 92 in the knob 86. The readout 116 may be, for example, a small LCD display. The readout 116 is thus on an exterior portion of the regulator 10 and the signal from the transducer is present at an exterior portion of the regulator so that it can be observed or transmitted to enable the pressure in the regulator to be read.

[0054] When the face plate 54 moves axially in response to changes in pressure in the chamber 14, as described above, the sensor 110 moves also. To accommodate this movement, some slack is provided in the lead wires 112.

[0055] A power source, such as a watch battery, may be included in the electronics package 114 or elsewhere in the regulator 10. To conserve power, the electronics of the regulator 10 may be programmed so that the readout 116 is activated only when touched, and then only for a predetermined period of time, for example a few seconds.

[0056] If the fluid pressure downstream of the regulator 10 changes, that change is present in the fluid outlet 24 and, thus, in the chamber 14. Because of the presence of the opening 66 in the face plate 54, the change in fluid pressure is present also at the pressure sensor 110 on the inner side surface (non-wetted side) 60 of the bellows face plate.

[0057] The change in pressure on the transducer 110 causes a portion of the pressure sensor to flex by a minute amount. This flexing causes a change in the output signal of the transducer 110. The changed output signal is transmitted to the electronics package 114 over the lead wires 112. The electronics package 114 controls the readout 116 so that the pressure readout is changed accordingly. Thus, the change in pressure on the downstream side of the regulator 10 is visible directly on the regulator itself, via a digital readout 116.

[0058] Were the bellows face plate 54 not rigid, its flexing might be picked up by the transducer 110. Because the transducer 110 is so sensitive, attempting to read the flexing of the face plate 54 could overwhelm the transducer 110. Therefore, the sensor 110 must be mounted on a rigid member. Thus, the base plate 54 is designed to be rigid, as described above, that is, rigid enough so that pressure changes in the chamber 14 are sensed only via the pressure sensor 110 directly and not through flexing of the face plate.

[0059] Having the lead wires 112 extend upward from the face plate 54 allows the readout 116 to be located directly on the regulator 10 itself. This on-board location of the readout 116 provides for a very compact device.

[0060] Because the sensor 110 is mounted on the inner side surface (the non- wetted side) 60 of the face plate 54, the lead wires 112 do not have to pass through the sealed chamber 14. Also, the lead wires 112 do not have to pass through the valve body 12 and/or outside the regulator 10. This provides a single, enclosed device contained within the existing envelope of the regulator 10.

[0061] Incorporating the pressure transducer 110 into the pressure regulator 10 avoids the need for an additional component in the fluid flow system. It also provides visual feedback (pressure readout) directly to the operator when the operator is adjusting the pressure by turning the knob 86.

[0062] The invention is applicable to regulators having movable walls of types other than the bellows shown in Fig. 2. As one example, Fig. 5 illustrates a portion of a regulator 10a constructed in accordance with a second embodiment of the invention.

In the regulator 10a, the bellows 52 (Fig. 2) is replaced with a flexible diaphragm 120 having a wetted side 121 and a non-wetted side 123. The diaphragm 120 may be made from metal, or from plastic, in a manner known in the art. The diaphragm 120 acts as a movable wall that at least partially closes the pressurized fluid chamber in the regulator 10a.

[0063] The diaphragm 120 is flexible enough that mounting a pressure transducer directly on the diaphragm would lead to unacceptably large amounts of deflection being transmitted to the transducer--the transducer would sense deflection of the diaphragm itself. To prevent this, a rigid member is mounted on the diaphragm 120, and the pressure sensor is mounted on the rigid member.

[0064] As illustrated in Fig. 5, the rigid member is a cup-shaped member, or cup 122, made from a suitably rigid material, such as metal. The cup 122 has a cylindrical side wall 124 and a radially extending end wall 126. The side wall 124 of the cup 122 defines a chamber 128 within the cup. An annular mounting flange 130 extends radially outward from the side wall 124.

[0065] The side wall 124 of the cup 122 extends through an opening 131 in the diaphragm 120. The mounting flange 130 overlies the diaphragm 120, and the cup 122 is welded or other wise secured to the diaphragm, with the. chamber 128 open to the wetted side 121 of the diaphragm. As a result, one side surface 132 of the end wall 126 of the cup 122 is wetted, and the other side surface 134 is non-wetted.

[0066] A small opening 136 is formed in the end wall 124 of the cup 122. A pressure transducer 140 is sealed and secured to the side surface 134 of the end wall 126 of the cup 122, in a position overlying the opening 136 in the end wall. As a result, the pressure transducer 140 is exposed through the opening 136 to the fluid pressure in the chamber 128 in the cup 122. Because the chamber 128 is open to the wetted side 121 of the diaphragm 120, the transducer 140 is exposed to the fluid pressure in the regulator chamber. The transducer 140 is operative, as described above with reference to Figs. 1-4, to provide a signal indicative of the pressure at the regulator 10a. Lead wires shown partially at 142 connect the transducer 140 internally in the regulator to electronics and a readout, as described above.

[0067] The diaphragm 120 inevitably flexes in response to changes in pressure in the regulator 10a. The cup isolates the transducer 140 from that flexing. Therefore, a small and sensitive transducer 140 can be used on the flexible diaphragm 120, as desired.

[0068] Fig. 6 illustrates a portion of a regulator 1 Ob constructed in accordance with a third embodiment of the invention. Internally, the regulator 1 Ob can be constructed as described in any of the preceding embodiments. Thus, the regulator 1 Ob includes a pressure transducer (not shown) mounted on the non-wetted side of a bellows or diaphragm and having an output connected by internal lead wires to the upper end portion 150 of the regulator.

[0069] In the regulator lOb, the digital readout of the regulator 10 (Figs. 1-4) is replaced with an electrical connector 152 on the upper end portion 150 of the regulator lOb. The connector 152 on the regulator is adapted to receive an external electrical connector 154. The external connector 154 is connected by wires 156 to a readout (not shown) that is located off the regulator lOb. Thus, it can be seen that the present invention is not limited to a regulator having an on-board readout, but also includes a regulator having a hard-wired external readout.

[0070] Fig. 7 illustrates a portion of a regulator lOc constructed in accordance with a fourth embodiment of the invention. Internally, the regulator 1 Oc can be constructed as described in any of the preceding embodiments. Thus, the regulator lOc includes a pressure transducer (not shown) mounted on the non-wetted side of a bellows or diaphragm and having an output connected by internal lead wires to the upper end portion 160 of the regulator.

[0071] In the regulator lOc, the digital readout of the regulator 10 (Figs. 1-4) is replaced with an RF transmitter 162 on the upper end portion 160 of the regulator.

The RF transmitter 162 is adapted to transmit the output signal of the transducer to an external receiver 164. The external receiver 164 is connected to a readout (not shown) that is located off the regulator 106. Thus, the pressure reading at the regulator lOc can be read at any location with the range of transmission of the transmitter 162. Thus, it can be seen that the present invention is not limited to a regulator having an internal or external hard-wired readout, but also includes a regulator having an external wireless readout.

[0072] The invention is applicable also to regulators that have different flow paths than that shown in Fig. 2. For example, Fig. 8 is a view similar to Fig 2 of a regulator 10d constructed in accordance with a fifth embodiment of the invention.

The regulator 1 Od is a back pressure regulator, and thus effectively a pressure relief valve. Fluid enters the regulator lOd through the fluid flow passage 22 and exits through the passage 16. The regulator lOd has a poppet 34d that can seal against a seat 30d to prevent or restrict fluid flow. The poppet 34d is inside the wetted portion of the regulator lOd. The regulator 1 Od includes a pressure transducer 110 mounted on the non-wetted side of a movable wall (in this case a bellows face plate 54) and having an output connected by internal lead wires 112 to the upper end portion 150 of the regulator.

[0073] From the above description of the invention, those skilled in the art will perceive improvements, changes, and modifications in the invention. For example, the invention is applicable to flow control devices other than regulators, for example to show the on-off position of a valve. Such improvements, changes, and modifications within the skill of the art are intended to be included within the scope of the appended claims.