Linear motion electromechanical device utilizing nonlinear elements

Claim 2

A linear motion device comprising an armature of magnetic material movable to a plurality of positions along a linear path, a permanent magnet having a strong magnetic force acting on said armature to cause attraction thereof in a direction towards said permanent magnet, the attraction of the magnetic force on said armature decreasing as the distance of said armature increases from said permanent magnet to establish a magnetic force-armature position characteristic, a nonlinear spring contacting said armature and exerting a force thereon to bias said armature in a direction away from said permanent magnet, the force of said spring on said armature decreasing as the distance of said armature increases from said permanent magnet to establish a spring force-armature position characteristic, said spring having a construction such that the second-mentioned characteristic is proportionally opposite to the first-mentioned characteristic, and an electromagnet coupled to said permanent magnet and connected to a source of electrical power having an electromagnetic force for acting in conjunction with the permanent-magnetic force.

Claim 3

A device as in claim 1 wherein the permanent-magnetic force is proportionally stronger than the spring force and wherein said electromagnet is provided with means for causing the electromagnetic force to exist in a direction opposite to the permanent-magnetic force and at a value sufficiently high to reduce the permanent-magnetic force below that of the spring force in order to cause movement of said armature away from said permanent magnet.

Claim 4

A device as in claim 1 wherein the spring force is proportionally stronger than the permanent-magnetic force and wherein said electromagnet is provided with means for causing the electromagnetic force to exist in the same direction as the permanent-magnetic force and at a value sufficiently high to augment the permanent-magnetic force to a value greater than that of the spring force to cause movement of said armature towards said permanent magnet.

Claim 5

A device as in claim 1 further including a potentiometric circuit coupled between said electromagnet and said source of electrical power and wherein the permanent-magnetic force is proportionally stronger than the spring force and said electromagnet is provided with means for causing the electromagnetic force to exist in a direction opposite to the permanent-magnetic force, said potentiometric circuit having power varying means capable of causing the electromagnetic force to exist at values sufficient to reduce the permanent-magnetic force attraction on said armature sufficient to balance the spring force at a specific one of the armature positions.

Claim 6

A device as in claim 1 wherein the spring force is stronger than the permanent-magnet force at one of the armature positions and weaker than the permanent-magnet force at another of the armature positions and wherein said electromagnet includes means for causing the electromagnetic force to exist selectively in a first direction opposite to that of the permanent magnetic force and in a second direction the same as that of the permanent-magnetic force, the electromagnetic force having a sufficiently high value in the first and second directions respectively to reduce the permanent magnetic force below the spring force at the one armature position and to augment the permanent-magnetic force above the spring force at the other armature position.

Claim 7

A device as in claim 1 further including poles of magnetic material extending from said permanent magnet, said armature positioned at said poles and providing a closed path for the flux of said permanent magnet, and said electromagnet positioned in one portion of the path in said poles, said electromagnet capable of producing a flux sufficient to saturate said portion of said poles to decrease and to effectively eliminate the permanent-magnet force.

Claim 8

A device as in claim 1 wherein said spring is selected from the group consiSting of Belleville washers, conical springs, and variable-pitch springs.

Claim 9

A linear motion device having an axis comprising an annularly shaped permanent magnet coaxially positioned on the axis and having a pair of poles, said poles having faces extending in the same direction, an annularly shaped electromagnet secured to said permanent magnet and positioned in the plane of said permanent magnet and coaxially positioned along the axis, a source of power connected to said electromagnet for energization thereof, an armature of ferromagnetic material positioned over said poles, and a nonlinear spring positioned between said armature and said magnets and exerting a force tending to bias said armature away from said pole faces, said permanent magnet producing a magnetic flux and force lines in a first direction through said poles and attracting said armature towards said pole faces to form a completely closed magnetic flux path, the force of said permanent magnet being greater than the force of said spring, and said electromagnet capable of producing force lines upon energization thereof in a direction opposite to the direction of the permanent magnet force lines, the force of said electromagnet being sufficient to decrease the permanent magnet force to a value below that of said spring to permit movement of said armature away from said pole faces.

Claim 10

A linear motion device having an axis comprising an annularly shaped permanent magnet coaxially positioned on the axis and having a pair of poles, said poles having faces extending in the same direction, an annularly shaped electromagnet secured to said permanent magnet and positioned in the plane of said permanent magnet and coaxially positioned along the axis, a source of power connected to said electromagnet for energization thereof, an armature of ferromagnetic material positioned over said poles, and a nonlinear spring positioned between said armature and said magnets and exerting a force tending to bias said armature away from said pole faces, said permanent magnet producing a magnetic flux and force lines in a first direction through said poles and attracting said armature towards said pole faces to form a completely closed magnetic flux path, the force of said permanent magnet being greater than the force of said spring, and said electromagnet capable of producing force lines upon energization thereof in a direction opposite to the direction of the permanent magnet force lines, the force of said electromagnet being sufficient to decrease the permanent magnet force to a value below that of said spring to permit movement of said armature away from said pole faces.

Claim 11

A linear motion device having an axis comprising an annularly shaped permanent magnet coaxially positioned on the axis and having a pair of poles, said poles having faces extending in the same direction, an annularly shaped electromagnet secured to said permanent magnet, a source of power connected to said electromagnet for energization thereof, an armature of ferromagnetic material positioned over said pole faces, and a nonlinear spring positioned between said armature and said magnets exerting a force tending to bias said armature away from said pole faces, said permanent magnet producing a magnetic flux in a first path through said poles and a force attracting said armature towards said pole faces, the force of said permanent magnet being greater than the force of said spring, and said electromagnet capable of producing a flux upon energization thereof in at least a portion of said poles and a portion of the first path of the permanent magnet flux, the flux of said electromagnet being sufficient to cause saturation of the common portion of said poles to reduce the force of said permanent magnet to permit movement of said armature away from said pole faces.

Claim 12

A linear motion device having an axis comprising an annularly shaped permanent magnet coaxially positioned on the axis and having a pair of poles, said poles having faces extending in the same direction, an annularly shaped electromagnet secured to said permanent magnet, a source of power connected to said electromagnet for energization thereof, an armature of ferromagnetic material positioned over said pole faces, and a nonlinear spring positioned between said armature and said magnets exerting a force tending to bias said armature away from said pole faces, said permanent magnet producing a magnetic flux in a first path through said poles and a force attracting said armature towards said pole faces, the force of said permanent magnet being greater than the force of said spring, and said electromagnet capable of producing a flux upon energization thereof in at least a portion of said poles and a portion of the first path of the permanent magnet flux, the flux of said electromagnet being sufficient to cause saturation of the common portion of said poles to reduce the force of said permanent magnet to permit movement of said armature away from said pole faces.

Claim 13

A linear motion device having an axis comprising an annularly shaped permanent magnet coaxially positioned on the axis and having a pair of poles, said poles having faces extending in the same direction, an annularly shaped electromagnet secured to said permanent magnet, a source of power connected to said electromagnet for energization thereof and means coupled between said electromagnet and said power source for varying the amount of current furnished to said electromagnet, an armature of ferromagnetic material placed over said pole faces, and a nonlinear spring positioned between said armature and said magnets exerting a force tending to bias said armature away from said poles to provide, with said armature a spring-armature displacement force-stroke characteristic, said permanent magnet producing a magnetic flux in a first direction through said poles and a force attracting said armature towards said pole faces and providing a permanent-magnet armature displacement force-stroke characteristic, the force of said permanent magnet being greater than the force of said spring, and said electromagnet capable of producing fluxes of different values in response to supply of the current in a direction opposite to the direction of the permanent magnet flux so as to provide, with the second-mentioned force-stroke characteristic, a plurality of electromagnet-permanent magnet arMature displacement force-stroke characteristics, the first-mentioned characteristic passing through all the third-mentioned characteristics to establish a plurality of magnet-spring balance points, said means capable of establishing a value of the current for each of the balance points to permit movement of said armature away from said pole faces to a plurality of positions.

Claim 14

A linear motion device having an axis comprising an annularly shaped permanent magnet coaxially positioned on the axis and having a pair of poles, said poles having faces extending in the same direction, an annularly shaped electromagnet secured to said permanent magnet, a source of power connected to said electromagnet for energization thereof and means coupled between said electromagnet and said power source for varying the amount of current furnished to said electromagnet, an armature of ferromagnetic material placed over said pole faces, and a nonlinear spring positioned between said armature and said magnets exerting a force tending to bias said armature away from said poles to provide, with said armature a spring-armature displacement force-stroke characteristic, said permanent magnet producing a magnetic flux in a first direction through said poles and a force attracting said armature towards said pole faces and providing a permanent-magnet armature displacement force-stroke characteristic, the force of said permanent magnet being greater than the force of said spring, and said electromagnet capable of producing fluxes of different values in response to supply of the current in a direction opposite to the direction of the permanent magnet flux so as to provide, with the second-mentioned force-stroke characteristic, a plurality of electromagnet-permanent magnet arMature displacement force-stroke characteristics, the first-mentioned characteristic passing through all the third-mentioned characteristics to establish a plurality of magnet-spring balance points, said means capable of establishing a value of the current for each of the balance points to permit movement of said armature away from said pole faces to a plurality of positions.