Detection of particle-inclusions in fluid flow utilizing a divided fluid path with a sensing coil about each path

Claim 2

Flow-apparatus comprising means defining a flow pathway, means for supplying matter to flow in a unidirectional stream along said pathway, and apparatus for the detection of particles in said stream during their passage along said pathway, said detection apparatus comprising means defining a junction point in said pathway, means dividing the pathway at said junction point into two parallel-connected sub-paths extending downstream from said point, first and second electrical coils, means mounting the first of said coils to embrace a first of the two sub-paths at a predetermined distance downstream from said junction point, means mounting the second of said coils to embrace the second of the two sub-paths at a distance downstream from said junction point substantially equal to said predetermined distance so that the effective path-length for passage along said pathway to said second coil is the same as that for passage to said first coil, and electrical circuit means coupled to the two coils to sense differentially transistory changes in the impedances of the coils.

Claim 3

Appaatus according to claim 1 wherein the said electrical circuit means comprises an electrical alternating-current bridge circuit, means connecting the two coils in the bridge circuit, the coils being connected in the bridge circuit to unbalance it in the event of change in impedance of one coil unaccompanied by a corresponding change in impedance of the other coil, and means for detecting transitory unbalance of the bridge circuit.

Claim 4

Apparatus according to claim 2 including means coupled to said circuit means to provide a measure of the number of occasions on which the bridgE circuit is unbalanced transitorily.

Claim 5

Fluid-flow apparatus comprising a pathway for fluid, means to supply fluid to flow in a unidirectional stream along said pathway, and detector means for the detection of particles in said fluid during their passage along said pathway, said detector means comprising means defining a junction point in said pathway, means dividing the pathway at said junction point into a plurality of parallel-connected sub-paths extending downstream from said point, said sub-paths being of substantially equal length to one another, a plurality of electrical coils, means mounting the coils to embrace the sub-paths at positions of substantially equal distance to one another downstream from said point in said pathway, each said coil embracing a different one of said sub-paths from any other of said coils, and electrical circuit means coupled to the coils to sense transitory changes in their impedances, said circuit means including means to discriminate between a first condition in which there is a transitory change in impedance of only one of the coils, and a second condition in which there is a transitory change substantially simultaneously in the impedance of more than one said coil.

Claim 6

Fluid-flow apparatus comprising a pathway for fluid, means to supply fluid to flow in a unidirectional stream along said pathway, and detector means for the detection of particles in said fluid during their passage along said pathway, said detector means comprising means defining a junction point in said pathway, means dividing the pathway at said junction point into a plurality of parallel-connected sub-paths extending downstream from said point, said sub-paths being of substantially equal length to one another, a plurality of electrical coils, means mounting the coils to embrace the sub-paths at positions of substantially equal distance to one another downstream from said point in said pathway, each said coil embracing a different one of said sub-paths from any other of said coils, and electrical circuit means coupled to the coils to sense transitory changes in their impedances, said circuit means including means to discriminate between a first condition in which there is a transitory change in impedance of only one of the coils, and a second condition in which there is a transitory change substantially simultaneously in the impedance of more than one said coil.

Claim 7

Apparatus according to claim 4 including means coupled to said circuit means to provide a measure of the number of occasions on which said first condition exists.

Claim 8

Apparatus according to claim 4 wherein said circuit means includes an alternating-current bridge circuit, connection means coupling the coils in the bridge circuit, the coils being coupled in the bridge circuit by said connection means to provide transitory unbalance of the bridge circuit upon each occurrence of said first condition and to retain the bridge circuit substantially balanced upon each occurrence of said second condition, and output means responsive to transitory unbalance of the bridge circuit.

Claim 9

Apparatus according to claim 6 wherein said output means comprises signal-supply means for supplying a signal in accordance with each transitory unbalance of the bridge circuit, signal-counting means for counting signals supplied thereto from the signal-supply means, and a signal channel for transmitting signals supplied by said signal-supply means to said signal-counting means, said channel including means to restrict the signals transmitted to said signal-counting means to those occurring within a predetermined frequency band.

Claim 10

Apparatus comprising a fluid-flow line, fluid-supply means for supplying fluid to flow in a unidirectional stream in said fluid-flow line, and detector means for the detection of particles flowing in said fluid-flow line, said detector means comprising tubing of electrically non-conductive material coupled in the fluid-flow line, means dividing the tubing into two parallel-connected sub-paths, first and second electrical coils, means mounting the said first coil to embrace a first of the two sub-paths, means mounting the said second coil to embrace the second of the two sub-paths at an effective distance downstream from said fluid-supply means substantially equal to the effective downstream distance of said first coil from said fluid-supply means, and electrical circuit means coupled to both of said first and second coils to sense transitory changes in their impedances, said circuit means including means to sense the condition in which there is a transitory change in impedance of either of the first and second coils unaccompanied substantially simultaneously by a corresponding transitory change in impedance of the other coil.

Claim 11

Apparatus comprising a fluid-flow line, fluid-supply means for supplying fluid to flow in a unidirectional stream in said fluid-flow line, and detector means for the detection of particles flowing in said fluid-flow line, said detector means comprising tubing of electrically non-conductive material coupled in the fluid-flow line, means dividing the tubing into two parallel-connected sub-paths, first and second electrical coils, means mounting the said first coil to embrace a first of the two sub-paths, means mounting the said second coil to embrace the second of the two sub-paths at an effective distance downstream from said fluid-supply means substantially equal to the effective downstream distance of said first coil from said fluid-supply means, and electrical circuit means coupled to both of said first and second coils to sense transitory changes in their impedances, said circuit means including means to sense the condition in which there is a transitory change in impedance of either of the first and second coils unaccompanied substantially simultaneously by a corresponding transitory change in impedance of the other coil.

Claim 12

Apparatus according to claim 8 including means to provide a measure of the number of occasions on which said condition is sensed by the said circuit means.

Claim 13

Apparatus for the detection of particles in their passage along a defined pathway, comprising means dividing the pathway into two parallel-connected sub-paths, a first electrical coil embracing a first of the said sub-paths, a second electrical coil embracing the second of Said sub-paths, electrical circuit means coupled to both said first and second coils to sense differentially transitory changes in the impedances of the coils, a third electrical coil embracing the said first sub-path at a position spaced lengthwise of the pathway from said first coil, means coupling the said third coil in said circuit means in opposite sense to said first coil, a fourth electrical coil embracing the said second sub-path at a position spaced lengthwise of the pathway from said second coil, and means coupling the said fourth coil in said circuit means in opposite sense to the said second coil.

Claim 14

Apparatus for the detection of particles in their passage along a defined pathway, comprising means dividing the pathway into two parallel-connected sub-paths, a first electrical coil embracing a first of the said sub-paths, a second electrical coil embracing the second of Said sub-paths, electrical circuit means coupled to both said first and second coils to sense differentially transitory changes in the impedances of the coils, a third electrical coil embracing the said first sub-path at a position spaced lengthwise of the pathway from said first coil, means coupling the said third coil in said circuit means in opposite sense to said first coil, a fourth electrical coil embracing the said second sub-path at a position spaced lengthwise of the pathway from said second coil, and means coupling the said fourth coil in said circuit means in opposite sense to the said second coil.

Claim 15

Apparatus for the detection of particles in their passage along a defined pathway comprising means dividing the pathway into a plurality of parallel-connected sub-paths, a plurality of electrical coils embracing the sub-paths, each said coil embracing a different one of the said paths from any other of said coils and electrical circuit means coupled to the coils to sense transitory changes in their impedances, said circuit means including an alternating-current bridge circuit, connection means coupling the coils in the bridge circuit, the coils being coupled in the bridge circuit by said connection means to provide transitory unbalance of the bridge circuit upon each occurrence of a first condition in which there is a transitory change in impedance of only one of the coils, and to retain the bridge circuit substantially balanced upon each occurrence of a second condition in which there is a transitory change in the impedance of more than one coil, and output means which is responsive to transitory unbalance of the bridge circuit and which comprises signal-supply means for supplying a signal in accordance with each transitory unbalance of the bridge circuit, signal-counting means for counting signals supplied thereto from the signal-supply means, and a signal channel for transmitting signals supplied by said signal-supply means to said signal-counting means, said channel including means to restrict the signals transmitted to said signal-counting means to those occurring within a predetermined frequency band, and means to suppress from the signals transmitted to said signal-counting means regularly-recurrent signals within said frequency band.

Claim 16

Apparatus for the detection of particles in their passage along a defined pathway comprising means dividing the pathway into a plurality of parallel-connected sub-paths, a plurality of electrical coils embracing the sub-paths, each said coil embracing a different one of the said paths from any other of said coils and electrical circuit means coupled to the coils to sense transitory changes in their impedances, said circuit means including an alternating-current bridge circuit, connection means coupling the coils in the bridge circuit, the coils being coupled in the bridge circuit by said connection means to provide transitory unbalance of the bridge circuit upon each occurrence of a first condition in which there is a transitory change in impedance of only one of the coils, and to retain the bridge circuit substantially balanced upon each occurrence of a second condition in which there is a transitory change in the impedance of more than one coil, and output means which is responsive to transitory unbalance of the bridge circuit and which comprises signal-supply means for supplying a signal in accordance with each transitory unbalance of the bridge circuit, signal-counting means for counting signals supplied thereto from the signal-supply means, and a signal channel for transmitting signals supplied by said signal-supply means to said signal-counting means, said channel including means to restrict the signals transmitted to said signal-counting means to those occurring within a predetermined frequency band, and means to suppress from the signals transmitted to said signal-counting means regularly-recurrent signals within said frequency band.

Claim 17

Apparatus for the detection of particles in their passage along a defined pathway comprising: means dividing the pathway into a plurality of parallel-connected subpaths; a plurality of pairs of electrical coils embracing the sub-paths, each said pair of coils comprising a first electrical coil that embraces a different one of said sub-paths from the first coil of any other of said coil pairs, and a second electrical coil that embraces the same one of said sub-paths as the first coil of the pair; and electrical circuit means coupled to said first coils of said coil pairs to sense transitory changes in their impedances, said circuit means including an alternating-current bridge circuit, connection means coupling the said first coils in the bridge circuit, the said first coils being coupled in the bridge circuit by said connection means to provide transitory unbalance of the bridge circuit upon each occurrence of a first condition in which there is a transitory change in impedance of only one of the said first coils, and to retain the bridge circuit substantially balanced upon each occurrence of a second condition in which there is a transitory change in the impedance of more than one of said first coils output means responsive to transitory unbalance of the bridge circuit, and further connection means coupling the said second coils of said coil pairs in the bridge circuit to provide transitory unbalance of the bridge circuit upon each occurrence of the condition in which there is a transitory change in impedance of only one of the said second coils, each said second coil being coupled in said bridge circuit in series with the said first coil with which it is paired in said coil pairs.

Claim 18

Apparatus for the detection of particles in their passage along a defined pathway comprising: means dividing the pathway into a plurality of parallel-connected subpaths; a plurality of pairs of electrical coils embracing the sub-paths, each said pair of coils comprising a first electrical coil that embraces a different one of said sub-paths from the first coil of any other of said coil pairs, and a second electrical coil that embraces the same one of said sub-paths as the first coil of the pair; and electrical circuit means coupled to said first coils of said coil pairs to sense transitory changes in their impedances, said circuit means including an alternating-current bridge circuit, connection means coupling the said first coils in the bridge circuit, the said first coils being coupled in the bridge circuit by said connection means to provide transitory unbalance of the bridge circuit upon each occurrence of a first condition in which there is a transitory change in impedance of only one of the said first coils, and to retain the bridge circuit substantially balanced upon each occurrence of a second condition in which there is a transitory change in the impedance of more than one of said first coils output means responsive to transitory unbalance of the bridge circuit, and further connection means coupling the said second coils of said coil pairs in the bridge circuit to provide transitory unbalance of the bridge circuit upon each occurrence of the condition in which there is a transitory change in impedance of only one of the said second coils, each said second coil being coupled in said bridge circuit in series with the said first coil with which it is paired in said coil pairs.

Claim 19

In a fluid-flow system, a fluid-flow line, means for supplying fluid to flow in one direction along said line, and apparatus for detecting particles passing along said fluid-flow line in the fluid stream and for categorizing the detected particles on the basis of a predetermined particle-property, said detecting apparatus comprising: means defining a junction point in said pathway; means dividing the pathway at said junction point into two parallel-connected sub-paths extending downstream from said point; two electrical coils embracing different ones of the sub-paths at substantially equal distances to one another downstream from said junction point; electrical circuit means coupled to the coils to sense differentially transitory changes in the impedances of the coils resulting from the passage of successive particles along said fluid-flow line, the sensed differential impedance-changes varying in magnitude in accordance with variation in the magnitude of said property from one to another of the successive particles, and said circuit means including signal-deriving means for deriving signals dependent in amplitude upon the magnitudes of the sensed differential impedance-changes; and a plurality of output means coupled to said circuit means to receive said signals derived by said signal-deriving means, each said output means being operative to respond to only those of said derived signals that have an amplitude exceeding a predetermined threshold level to provide an output representation dependent on the number of such signals received from the said signal deriving means, and wherein different ones of said output means are operative to different threshold levels from one another so that their output representations are dependent on the numbers of particles passing along said fluid-flow line, according to respective categorizations based on said property.

Claim 20

In a fluid-flow system, a fluid-flow line, means for supplying fluid to flow in one direction along said line, and apparatus for detecting particles passing along said fluid-flow line in the fluid stream and for categorizing the detected particles on the basis of a predetermined particle-property, said detecting apparatus comprising: means defining a junction point in said pathway; means dividing the pathway at said junction point into two parallel-connected sub-paths extending downstream from said point; two electrical coils embracing different ones of the sub-paths at substantially equal distances to one another downstream from said junction point; electrical circuit means coupled to the coils to sense differentially transitory changes in the impedances of the coils resulting from the passage of successive particles along said fluid-flow line, the sensed differential impedance-changes varying in magnitude in accordance with variation in the magnitude of said property from one to another of the successive particles, and said circuit means including signal-deriving means for deriving signals dependent in amplitude upon the magnitudes of the sensed differential impedance-changes; and a plurality of output means coupled to said circuit means to receive said signals derived by said signal-deriving means, each said output means being operative to respond to only those of said derived signals that have an amplitude exceeding a predetermined threshold level to provide an output representation dependent on the number of such signals received from the said signal deriving means, and wherein different ones of said output means are operative to different threshold levels from one another so that their output representations are dependent on the numbers of particles passing along said fluid-flow line, according to respective categorizations based on said property.