Transducer system for detecting and measuring mechanical loads or stresses

Claim 2

A transducer system for detecting and measuring a mechanical load comprising a magnetic core constructed of laminated sheets of a metal magnetic substance and defining a closed magnetic path having no air gap therein, at least one coil wound around said core, a transformer having input and output terminals, means for connecting the output terminals of said transformer across said coil, a power source of constant a.c. voltage, means for connecting said power source across the input terminals of said transformer, means for establishing the voltage output of said power source at a value causing maximum permeability of said core, a rectifying circuit associated with said coil for producing a d.c. voltage corresponding to the variation of current flowing through said coil, said rectifying circuit having an effective impedance corresponding to no more than one-fifth of the impedance of said coil, when maximum stress is applied to said core, meter means responsive to said d.c. voltage, and means for imparting a prestress mechanically to said core whereby the magnitude of load as applied to said core is determinable from said meter means.

Claim 3

A transducer system for detecting and measuring a mechanical load comprising a magnetic core constructed of laminated sheets of a metal magnetic substance and defining a closed magnetic path having no air gap therein, at least one coil wound around said core, an input transformer having input and output terminals, means for connecting the output terminals of said input transformer across said coil, a power source of constant a.c. voltage, means for connecting said power source across the input terminals of said input transformer, means for establishing the voltage output of said power source at a value causing maximum permeability of said core, an output transformer having input and output terminals, means for coupling the input terminals of said output transformer to said coil, to produce at the output terminals thereof a current having variation corresponding to the variation of current through said coil, said output transformer having an impedance at said input terminals corresponding to no more than one-fifth of the impedance of said coils under maximum stress, a rectifying circuit associated with the output terminals of said output transformer and resistance means for producing a d.c. voltage corresponding to the variation of current flowing through said coil.

Claim 4

A transducer system for detecting and measuring a mechanical load comprising a magnetic core constructed of laminated sheets of a metal magnetic substance and defining a closed magnetic path having no air gap therein, at least one coil wound around said core, an input transformer having input and output terminals, means for connecting the output terminals of said input transformer across said coil, a power source of constant a.c. voltage, means for connecting said power source across the input terminals of said input transformer, means for establishing the voltage output of said power source at a value causing maximum permeability of said core, an output transformer having input and output terminals, means for coupling the input terminals of said output transformer to said coil, to produce at the output terminals thereof a current having variation corresponding to the variation of current through said coil, said output transformer having an impedance at said input terminals corresponding to no more than one-fifth of the impedance of said coils under maximum stress, a rectifying circuit associated with the output terminals of said output transformer and resistance means for producing a d.c. voltage corresponding to the variation of current flowing through said coil.

Claim 5

A transducer system as in claim 2, further comprising upper and lower load seat members disposed respectively on and beneath said magnetic core, said seat members being mechanically connected together by stud and nut means for providing and adjusting mechanical prestress imparted to said magnetic core, diaphragm means provided on said upper load seat member and casing means enclosing said magnetic core together with said upper and lower load seat members and said diaphragm means and having at its upper central part a steel ball, said steel ball being engageable with the load to be detected and measured.

Claim 6

A transducer system as in claim 2, in which said magnetic core consists of two members aligned in a symmetrical manner and fixed by means of two supporting frames, common upper and lower seat members disposed respectively on and beneath said two core members, said seat members being mechanically coNnected together by stud and nut means for providing and adjusting mechanical prestress imparted to said magnetic core members, diaphragm means provided on said upper seat member, and casing means enclosing said magnetic core members together with said seat members and diaphragm means and having at its upper central part a steel ball, said steel ball being engageable with the load to be detected and measured.

Claim 7

A transducer system for detecting and measuring a mechanical load comprising a magnetic reactor including a magnetic core constructed of laminated sheets of metal magnetic substance and defining a closed magnetic path having no air gap therein, and a primary coil and a secondary coil wound around said core, a power source of constant a.c. voltage, means for connecting said primary coil across said power source, first resistance means connected in series circuit between said power source and said primary coil for providing a first voltage signal proportional to the variation of current flowing through said primary coil, said power source and said first resistance means being characterized that when the effective impedance Z of said reactor is represented as: Z r + X(1) where r is the real resistance and X is the reactance of said reactor when no load is impressed on said magnetic core, the following equation is established: X/(R+r) X1/(R+r1)(2) where r1 is the real resistance and X1 is the reactance of said reactor when a load is impressed on said magnetic core and R represents the resistance of said first resistance means, second resistance means associated with said secondary coil for providing a second voltage signal proportional to the voltage induced in said secondary coil, means associated with said first and second resistance means for producing a difference voltage signal proportional to a difference between said first and second voltage signals, and means for imparting a prestress mechanically to said core whereby the magnitude of said load is determinable from said difference voltage signal.

Claim 8

A transducer system for detecting and measuring a mechanical load comprising a magnetic reactor including a magnetic core constructed of laminated sheets of metal magnetic substance and defining a closed magnetic path having no air gap therein, and a primary coil and a secondary coil wound around said core, a power source of constant a.c. voltage, means for connecting said primary coil across said power source, first resistance means connected in series circuit between said power source and said primary coil for providing a first voltage signal proportional to the variation of current flowing through said primary coil, said power source and said first resistance means being characterized that when the effective impedance Z of said reactor is represented as: Z r + X(1) where r is the real resistance and X is the reactance of said reactor when no load is impressed on said magnetic core, the following equation is established: X/(R+r) X1/(R+r1)(2) where r1 is the real resistance and X1 is the reactance of said reactor when a load is impressed on said magnetic core and R represents the resistance of said first resistance means, second resistance means associated with said secondary coil for providing a second voltage signal proportional to the voltage induced in said secondary coil, means associated with said first and second resistance means for producing a difference voltage signal proportional to a difference between said first and second voltage signals, and means for imparting a prestress mechanically to said core whereby the magnitude of said load is determinable from said difference voltage signal.

Claim 9

A transducer system as in claim 5, in which said magnetic core consists of two members which are aligned in a symmetrical manner and fixed by means of two supporting frames, common upper and lower seat members disposed respectively on and beneath said two core members, said seat members being mechanically connected together by stud and nut means for providing and adjusting mechanical prestress imparted to said magnetic core members, diaphragm means provided on said upper seat member, and casing means enclosing said magnetic core members together with said seat members and diaphragm means and having at its upper central part a steel ball, said steel ball being engageable with the load to be detected and measured.

Claim 10

A transducer system for detecting and measuring a mechanical load comprising a magnetic reactor including a plurality of magnetic cores, each of said cores being constructed of laminated sheets of metal magnetic substance and defining a closed magnetic path having no air gap therein, and primary coils and secondary coils wound around said cores, said cores being constructed to receive parts of said load to be measured, a power source of constant a.c. voltage, means for connecting said primary coils across said power source, a first rectifying circuit connected in series with said primary coils for producing across first output terminals a first d.c. voltage signal proportional to the variation of current flowing through said primary coils, a first resistance means connected across said first output terminals, said power source and said first resistance means being characterized that when the effective impedance Z of said reactor is represented as: Z r + X (1) where r is the real resistance and X is the reactance of said reactor when No load is impressed on said magnetic core, the following equation is established: X/(R+r) X1/(R+r1)(2) where r1 is the real resistance and X1 is the reactance of said reactor when a load is impressed on said magnetic core and R represents the resistance of said first resistance means, a second rectifying circuit connected across said secondary windings for producing across second output terminals a second d.c. voltage signal proportional to the variation of current flowing through said secondary coils, a second resistance means connected across said second output terminals, means associated with said first and second resistance means for producing a difference voltage signal proportional to a difference between said first and second d.c. voltage signal, and means for imparting a prestress mechanically to said cores whereby the magnitude of said load is determinable from said difference voltage signal.

Claim 11

A transducer system for detecting and measuring a mechanical load comprising a magnetic reactor including a plurality of magnetic cores, each of said cores being constructed of laminated sheets of metal magnetic substance and defining a closed magnetic path having no air gap therein, and primary coils and secondary coils wound around said cores, said cores being constructed to receive parts of said load to be measured, a power source of constant a.c. voltage, means for connecting said primary coils across said power source, a first rectifying circuit connected in series with said primary coils for producing across first output terminals a first d.c. voltage signal proportional to the variation of current flowing through said primary coils, a first resistance means connected across said first output terminals, said power source and said first resistance means being characterized that when the effective impedance Z of said reactor is represented as: Z r + X (1) where r is the real resistance and X is the reactance of said reactor when No load is impressed on said magnetic core, the following equation is established: X/(R+r) X1/(R+r1)(2) where r1 is the real resistance and X1 is the reactance of said reactor when a load is impressed on said magnetic core and R represents the resistance of said first resistance means, a second rectifying circuit connected across said secondary windings for producing across second output terminals a second d.c. voltage signal proportional to the variation of current flowing through said secondary coils, a second resistance means connected across said second output terminals, means associated with said first and second resistance means for producing a difference voltage signal proportional to a difference between said first and second d.c. voltage signal, and means for imparting a prestress mechanically to said cores whereby the magnitude of said load is determinable from said difference voltage signal.

Claim 12

A transducer system for detecting and measuring a mechanical load comprising a magnetic reactor including a plurality of magnetic cores, each of said cores constructed of laminated sheets of a metal magnetic substance and defining a closed magnetic path having no air gap therein, and primary coils and secondary coils wound around said cores, said cores being constructed to receive parts of said load to be measured, a power source of a.c. voltage, means for connecting said primary coils across said power source, first resistance means associated with said primary coils for producing a first voltage signal proportional to the variation of current flowing through said primary coils, said power source and said first resistance means being characterized that when the effective impedance Z of said reactor is represented as:Z r + X(1) where r is the real resistance and X is the reactance of said reactor when no load is impressed on said magnetic core, the following equation is established: X/(R+r) X1/(R+r1)(2) where r1 is the real resistance and X1 is the reactance of said reactor when a load is impressed on said magnetic core and R represents the resistance of said first resistance means, second resistance means associated with said secondary coils for producing a second voltage signal proportional to the variation of current induced in said secondary coils, means associated with said first and second resistance means for producing a difference voltage signal proportional to a difference between said first and second voltage signals, and means for imparting prestress mechanically to said cores whereby the magnitude of said load is determinable from said difference voltage signal.

Claim 13

A transducer system for detecting and measuring a mechanical load comprising a magnetic reactor including a plurality of magnetic cores, each of said cores constructed of laminated sheets of a metal magnetic substance and defining a closed magnetic path having no air gap therein, and primary coils and secondary coils wound around said cores, said cores being constructed to receive parts of said load to be measured, a power source of a.c. voltage, means for connecting said primary coils across said power source, first resistance means associated with said primary coils for producing a first voltage signal proportional to the variation of current flowing through said primary coils, said power source and said first resistance means being characterized that when the effective impedance Z of said reactor is represented as:Z r + X(1) where r is the real resistance and X is the reactance of said reactor when no load is impressed on said magnetic core, the following equation is established: X/(R+r) X1/(R+r1)(2) where r1 is the real resistance and X1 is the reactance of said reactor when a load is impressed on said magnetic core and R represents the resistance of said first resistance means, second resistance means associated with said secondary coils for producing a second voltage signal proportional to the variation of current induced in said secondary coils, means associated with said first and second resistance means for producing a difference voltage signal proportional to a difference between said first and second voltage signals, and means for imparting prestress mechanically to said cores whereby the magnitude of said load is determinable from said difference voltage signal.