Flow sensor and system

Claim 2

A fluid flow sensor, comprising housing means, movable wall means resiliently urged by resilient means in a first direction, variable orifice means, inlet means effective for communicating with said variable orifice means, outlet means effective for communicating with said variable orifice means, said movable wall means being effective when acted upon by a fluid admitted through said inlet means to move in a second direction opposite to said first direction and in so doing to vary the effective flow area of said variable orifice means, additional means operatively connected to said movable wall means effective for producing an output signal indicative of the distance traveled by said movable wall means in said second direction, a cylindrical passage formed in said housing means, said movable wall means comprising a piston closely received and axially movable in said cylindrical passage, said piston comprising first and second axially spaced piston-like cylindrical portions respectively defining first and second axially spaced outer cylindrical land surfaces slidably engageable with said cylindrical passage, said first and second axially spaced piston-like cylindrical portions and said first and second axially spaced cylindrical land surfaces being respectively spaced from each other by and integrally formed with an intermediate necked-down portion as to thereby define a generally annular space as between said cylindrical passage and said intermediate necked-down portion, a first wall portion integrally formed with and carried by said first piston-like cylindrical portion as to extend generally transversely to the axis of said first cylindrical land surface as to prevent flow therethrough, said variable orifice means comprising an orifice of fixed dimension formeD through said first wall portion, a second passage formed through said intermediate necked-down portion and said second piston-like cylindrical portion as to be in communication with said outlet means and at least at times in communication with said orifice, said variable orifice means also comprising a valving element of fixed but contoured configuration, said valving element being supported generally between said inlet means and said first wall portion, said valving element being adapted to be received in and through said orifice to thereby define therebetween said effective flow area, said valving element also extending into said second passage as to be effective to vary said effective flow area as said piston and said first wall portion are axially moved toward and away from said inlet means by the action of said fluid against said first wall portion, said additional means comprising variable electrical resistance means, said resistance means comprising a generally elongated resistance element carried by said housing means, said elongated resistance element being situated as to have its longitudinal axis generally parallel to but spaced from the axis of said cylindrical passage as to result in said elongated resistance element being situated without said cylindrical passage, and electrical contact means carried by said intermediate necked-down portion and operatively slidingly engaging said elongated resistance element to complete an electrical circuit therethrough.

Claim 3

A fluid flow sensor according to claim 1 further comprising an electrical circuit effective for receiving an electrical signal from said variable electrical resistance means for integrating said electrical signal with related associated operating parameter-type signals for producing a linear output signal.

Claim 4

A fluid flow sensor according to claim 1 wherein said variable electrical resistance means comprises separate electrical conductor means of relatively low resistance compared to said elongated resistance element, and wherein said electrical contact means comprises a first contact portion effective for engaging said elongated resistance element and a second contact portion effective for simultaneously engaging said separate electrical conductor means.

Claim 5

A fluid flow sensor according to claim 3 wherein said elongated resistance element comprises a coil-type resistance element, and further comprising three electrical output terminals, wherein said coil-type resistance element has its opposite ends respectively electrically connected to first and second of said three electrical output terminals, and wherein said separate electrical conductor means has one end thereof electrically connected to a third of said three electrical output terminals.

Claim 6

A fluid flow sensor according to claim 1 wherein said resilient means comprises spring means carried within said cylindrical passage and situated as between generally said outlet means and said piston to thereby operatively engage said second piston-like cylindrical portion and resiliently urge said piston in said first direction whereby said effective flow area is generally progressively decreased.

Claim 7

A fluid flow sensor according to claim 5 wherein said housing means comprises a recess-like chamber portion formed generally externally of said housing means, cover means effective for forming a closure of said chamber portion, wherein said elongated resistance element is operatively secured to said cover means as to result in said elongated resistance element being received and contained within said chamber portion when said cover means forms said closure of said chamber portion, and further comprising elongated slot-like passage means formed through a portion of the wall of said cylindrical passage as to complete communication between said cylindrical passage and said chamber portion, and wherein said electrical contact means carried by said piston extends freely through said slot-like passage means.

Claim 8

A fluid flow sensor according to claim 6 Wherein said piston is formed of plastic material.

Claim 9

A fluid flow sensor according to claim 7 wherein acetal resin comprises said plastic material.

Claim 10

A fluid flow sensor, comprising housing means, movable wall means resiliently urged by resilient means in a first direction, variable orifice means, inlet means effective for communicating with said variable orifice means, outlet means effective for communicating with said variable orifice means, said movable wall means being effective when acted upon by a fluid admitted through said inlet means to move in a second direction opposite to said first direction and in so doing to vary the effective flow area of said variable orifice means, additional means operatively connected to said movable wall means effective for producing an output signal indicative of the distance traveled by said movable wall means in said second direction, a cylindrical passage formed in said housing means, said movable wall means comprising a piston closely received and axially movable in said cylindrical passage, said piston comprising first and second axially spaced piston-like cylindrical portions respectively defining first and second axially spaced outer cylindrical land surfaces slidably engageable with said cylindrical passage, said first and second axially spaced pistonlike cylindrical portions and said first and second axially spaced cylindrical land surfaces being respectively spaced from each other by and integrally formed with an intermediate neckeddown portion as to thereby define a generally annular space as between said cylindrical passage and said intermediate neckeddown portion, a first wall portion integrally formed with and carried by said second piston-like cylindrical portion as to extend generally transversely to the axis of said second cylindrical land surface as to prevent flow therethrough, a second passage formed through said intermediate necked-down portion and said first piston-like cylindrical portion as to be in communication with said inlet means, a plurality of generally radially directed first orifices formed through said intermediate necked-down portion as to thereby complete communication between said second passage and said annular space in said cylindrical passage, said variable orifice means comprising a tapered groove formed in the inner surface of said cylindrical passage generally longitudinally thereof, said groove being formed as to have a greater cross-sectional area as said groove more nearly approaches said outlet means, said second cylindrical land surface being effective to more nearly close communication between said groove and said annular space as said piston is moved in said first direction and said second cylindrical land surface being effective to more fully open said communication between said groove and said annular space as said piston is moved in said second direction by the action of said fluid against said first wall portion, said additional means comprising variable electrical resistance means, said resistance means comprising a generally elongated resistance element carried by said housing means, said elongated resistance element being situated as to have its longitudinal axis generally parallel to but spaced from the axis of said cylindrical passage as to result in said elongated resistance element being situated without said cylindrical passage, and electrical contact means carried by said intermediate necked-down portion and operatively slidingly engaging said elongated resistance element to complete an electrical circit therethrough.

Claim 11

A fluid flow sensor, comprising housing means, movable wall means resiliently urged by resilient means in a first direction, variable orifice means, inlet means effective for communicating with said variable orifice means, outlet means effective for communicating with said variable orifice means, said movable wall means being effective when acted upon by a fluid admitted through said inlet means to move in a second direction opposite to said first direction and in so doing to vary the effective flow area of said variable orifice means, additional means operatively connected to said movable wall means effective for producing an output signal indicative of the distance traveled by said movable wall means in said second direction, a cylindrical passage formed in said housing means, said movable wall means comprising a piston closely received and axially movable in said cylindrical passage, said piston comprising first and second axially spaced piston-like cylindrical portions respectively defining first and second axially spaced outer cylindrical land surfaces slidably engageable with said cylindrical passage, said first and second axially spaced pistonlike cylindrical portions and said first and second axially spaced cylindrical land surfaces being respectively spaced from each other by and integrally formed with an intermediate neckeddown portion as to thereby define a generally annular space as between said cylindrical passage and said intermediate neckeddown portion, a first wall portion integrally formed with and carried by said second piston-like cylindrical portion as to extend generally transversely to the axis of said second cylindrical land surface as to prevent flow therethrough, a second passage formed through said intermediate necked-down portion and said first piston-like cylindrical portion as to be in communication with said inlet means, a plurality of generally radially directed first orifices formed through said intermediate necked-down portion as to thereby complete communication between said second passage and said annular space in said cylindrical passage, said variable orifice means comprising a tapered groove formed in the inner surface of said cylindrical passage generally longitudinally thereof, said groove being formed as to have a greater cross-sectional area as said groove more nearly approaches said outlet means, said second cylindrical land surface being effective to more nearly close communication between said groove and said annular space as said piston is moved in said first direction and said second cylindrical land surface being effective to more fully open said communication between said groove and said annular space as said piston is moved in said second direction by the action of said fluid against said first wall portion, said additional means comprising variable electrical resistance means, said resistance means comprising a generally elongated resistance element carried by said housing means, said elongated resistance element being situated as to have its longitudinal axis generally parallel to but spaced from the axis of said cylindrical passage as to result in said elongated resistance element being situated without said cylindrical passage, and electrical contact means carried by said intermediate necked-down portion and operatively slidingly engaging said elongated resistance element to complete an electrical circit therethrough.