Extruder pressure sensor

Claim 2

A pressure sensor including a housing, means at a first end of said housing comprising a first diaphragm in position to be deflected from its normal position due to pressure to be sensed, movable wall means in said housing at a point remote from said first diaphragm and forming a chamber in said housing, manually removable means to permit removal of said movable wall means from said housing, a source of fluid under pressure, a first passageway defined in said housing and open to said source of fluid under pressure, a unitary force-balance valve assembly positioned within said first passageway, means to connect said unitary force-balance valve assembly to move with said movable wall means, an annular valve seat formed within said first passageway adjacent said first diaphragm, said force-balance valve assembly including valve means having a surface adapted to mate with said valve seat, a second passageway defined within said unitary force-balance valve assembly, means opening through said force-balance valve assembly to said second passageway on a side of said valve surface opposite from the inlet from said source of fluid under pressure, means coupling said valve means and said first diaphragm whereby movement of said first diaphragm under increased pressure will cause said valve means to move so that the valve surface of said valve means moves away from said valve seat and permits fluid under pressure to move from said source and first passageway into said second passageway, said second passageway opening into said chamber, increased pressure in said chamber causing said movable wall means to exert a force on said force-balance valve assembly to tend to oppose pressure on said first diaphragm, and pressure-responsive readout means associated with said chamber, said unitary force-balance valve assembly fitting within said first passageway between said movable wall means and said valve means and being of size to be removable from said first passageway in direction toward said movable wall means.

Claim 3

The combination as specified in claim 1 wherein said unitary force-balance valve assembly includes a rod portion extending from said valve means to said movable wall means, said rod portion being reduced in cross-sectional area adjacent said valve means to permit said rod portion to flex with respect to said valve means for alignment of said valve means and said valve seat.

Claim 4

The combination as specified in claim 2 wherein said movable wall means comprises a flexible diaphragm, said housing including a member removably sealingly clamping said flexible diaphragm around its peripheral edges, said chamber being formed on said diaphragm on a side thereof opposite from said valve means.

Claim 5

The combination of as specified in claim 2 and an orifice leading from said chamber of size to restrict flow of fluid outwardly from said chamber.

Claim 6

A pressure sensor including a housing, means at a first end of said housing comprising a first diaphragm in position to be deflected from its normal position due to pressure to be sensed, said housing defining an elongated stem member extending from adjacent said first diaphragm to a remote second end, movable wall means in said housing at a point remote from said first diaphRagm and forming a chamber in said housing, a source of fluid under pressure, a first fluid passageway defined in said stem member, said passageway communicating with said source of fluid under pressure, a second fluid passageway opening to said chamber, a unitary force-rebalance valve assembly within said stem member and including valve means located closely adjacent to and spaced from said first diaphragm and controlling fluid flow between said first and second passageways, said valve means comprising an annular shoulder surface formed inside said stem member and positioned adjacent to said first diaphragm, and a mating surface on said unitary force-rebalance valve assembly, means coupling said valve means to said first diaphragm whereby movement of said first diaphragm under increased pressure will adjust said valve means to change flow of fluid through said first passageway to said second passageway and said chamber and cause a change of pressure in said chamber, said force-rebalance valve assembly including a rod portion movable with said movable wall means and transferring force from said movable wall means through said valve means to the first diaphragm to provide an opposing force on said first diaphragm under increased pressure in said chamber to thereby balance the pressure on the first diaphragm, said rod portion of said unitary force-rebalance valve assembly being reduced in cross-sectional area adjacent said valve means and in a location between the movable wall means and said valve means to permit increased flexibility of said valve means with respect to said rod portion when under force from the movable wall means.

Claim 7

A pressure sensor including a housing, means at a first end of said housing comprising a first diaphragm in position to be deflected from its normal position due to pressure to be sensed, said housing defining an elongated stem member extending from adjacent said first diaphragm to a remote second end, movable wall means in said housing at a point remote from said first diaphRagm and forming a chamber in said housing, a source of fluid under pressure, a first fluid passageway defined in said stem member, said passageway communicating with said source of fluid under pressure, a second fluid passageway opening to said chamber, a unitary force-rebalance valve assembly within said stem member and including valve means located closely adjacent to and spaced from said first diaphragm and controlling fluid flow between said first and second passageways, said valve means comprising an annular shoulder surface formed inside said stem member and positioned adjacent to said first diaphragm, and a mating surface on said unitary force-rebalance valve assembly, means coupling said valve means to said first diaphragm whereby movement of said first diaphragm under increased pressure will adjust said valve means to change flow of fluid through said first passageway to said second passageway and said chamber and cause a change of pressure in said chamber, said force-rebalance valve assembly including a rod portion movable with said movable wall means and transferring force from said movable wall means through said valve means to the first diaphragm to provide an opposing force on said first diaphragm under increased pressure in said chamber to thereby balance the pressure on the first diaphragm, said rod portion of said unitary force-rebalance valve assembly being reduced in cross-sectional area adjacent said valve means and in a location between the movable wall means and said valve means to permit increased flexibility of said valve means with respect to said rod portion when under force from the movable wall means.

Claim 8

The combination as specified in claim 5 wherein said unitary force-rebalance valve assembly is tubular, and has an interior opening comprising said second passageway.

Claim 9

The combination as specified in claim 6 and pressure-responsive readout means communicating with said chamber.

Claim 10

The combination as specified in claim 5 wherein said valve surface is frustoconical.

Claim 11

A pressure sensor including a housing comprising an elongated tubular stem member having a straight first passageway defined longitudinally therethrough, means adjacent a first end of said stem member for mounting said sensor in position to sense pressure, means at the first end of said housing closing said first passageway comprising a first diaphragm in position to deflect from its normal position due to pressure to be sensed, movable wall means in said housing adjacent an end of said elongated stem remote from said first diaphragm and forming one wall of a chamber, a manually removable cap member forming closing walls of said chamber on a side of said movable wall means opposite from said first passageway, a source of fluid under pressure open to said first passageway at a pressure inlet opening, a shoulder defining an open center annular valve seat surface around the interior of said first passageway and facing away from the first diaphragm and being spaced from and adjacent said first diaphragm, a unitary tubular force-rebalance-rod valve assembly mounted within said first straight passageway and extending between said first diaphragm and said movable wall means and including first and second end portions, valve means on said rod valve assembly including a valve surface defined on said tubular member around the exterior thereof and mating with said valve seat, said first rod portion extending from said movable wall to said valve means and said second rod portion extending from said valve surface toward said first diaphragm and coupled thereto, said valve surface controlling fluid flow across said valve seat, an interior passageway in said rod valve assembly opening to said chamber and to the straight first passageway on a side of said valve seat opposite from the pressure inlet opening, means to slidably seal said first rod portion with respect to said first passageway on a side thereof opposite the pressure inlet from said valve means, said first rod portioN being connected to said removable wall means, said second rod portion being of size to pass through the open center defined by said annular valve seat, said rod portions transferring force from said movable wall means through said valve means to the first diaphragm to provide an opposing force on said first diaphragm, said valve means being of size to fit within said first passageway to thereby permit removal of said unitary force-rebalancing valve assembly from said housing with said movable wall means in a direction away from the first diaphragm when the manually removable means is removed.

Claim 12

A pressure sensor including a housing comprising an elongated tubular stem member having a straight first passageway defined longitudinally therethrough, means adjacent a first end of said stem member for mounting said sensor in position to sense pressure, means at the first end of said housing closing said first passageway comprising a first diaphragm in position to deflect from its normal position due to pressure to be sensed, movable wall means in said housing adjacent an end of said elongated stem remote from said first diaphragm and forming one wall of a chamber, a manually removable cap member forming closing walls of said chamber on a side of said movable wall means opposite from said first passageway, a source of fluid under pressure open to said first passageway at a pressure inlet opening, a shoulder defining an open center annular valve seat surface around the interior of said first passageway and facing away from the first diaphragm and being spaced from and adjacent said first diaphragm, a unitary tubular force-rebalance-rod valve assembly mounted within said first straight passageway and extending between said first diaphragm and said movable wall means and including first and second end portions, valve means on said rod valve assembly including a valve surface defined on said tubular member around the exterior thereof and mating with said valve seat, said first rod portion extending from said movable wall to said valve means and said second rod portion extending from said valve surface toward said first diaphragm and coupled thereto, said valve surface controlling fluid flow across said valve seat, an interior passageway in said rod valve assembly opening to said chamber and to the straight first passageway on a side of said valve seat opposite from the pressure inlet opening, means to slidably seal said first rod portion with respect to said first passageway on a side thereof opposite the pressure inlet from said valve means, said first rod portioN being connected to said removable wall means, said second rod portion being of size to pass through the open center defined by said annular valve seat, said rod portions transferring force from said movable wall means through said valve means to the first diaphragm to provide an opposing force on said first diaphragm, said valve means being of size to fit within said first passageway to thereby permit removal of said unitary force-rebalancing valve assembly from said housing with said movable wall means in a direction away from the first diaphragm when the manually removable means is removed.

Claim 13

The combination of claim 9 wherein said rod valve assembly includes means forming a relief area on the outside of said first rod portion to substantially reduce the cross-sectional area of said first rod portion on a side thereof toward said movable wall means to permit flexing of the valve means for alignment with said valve seat.

Claim 14

The combination of claim 10 wherein said movable wall means comprises a flexible diaphragm.