Permanent magnet translational motor with auxiliary electromagnet

Claim 2

A permanent magnet translational motor comprising a shell having an outer wall with a pair of closed ends enclosing a hollow interior, an elongated core extending through the hollow interior of the shell from one closed end to the other, permanent magnet means in the interior of the shell surrounding a predetermined length of the core, the permanent magnet means being spaced laterally from the core to form a narrow working air gap between the permanent magnet means and the core, with a magnetic field being established across the working air gap, the core having a first portion of its length located in the working air gap and a second portion of its length located adjacent to but outside of the working air gap, a movable drive coil located in the working air gap and surrounding the first portion of the core, the drive coil being connected To a first source of electrical power and being movable back and forth relative to the first portion of the core in the magnetic field in response to changes in electric current passing through it, the drive coil having opposed mounting means extending outwardly therefrom through corresponding openings in the shell outer wall for attachment to a load for applying force to the load in response to movement of the drive coil, and an auxiliary coil located within the interior of the shell and wound around the second portion of the core such that the drive coil is movable toward and away from the auxiliary coil, the auxiliary coil being connected to a second source of electrical power independent of the power source associated with the drive coil for varying the magnetic field across the working air gap in response to changes in electric current passing through the auxiliary coil to increase the maximum force which may be developed by the drive coil.

Claim 3

Apparatus according to claim 1 in which the magnetic field established by the permanent magnet means defines a closed path extending in opposite directions along the core, across the closed ends of the shell, and along the outer wall of the shell.

Claim 4

Apparatus according to claim 1 in which the shell is cylindrical, and the core is a cylindrical body extending coaxially along the longitudinal axis of the cylindrical shell, the drive coil being an annular body adapted to move back and forth in an enclosed annular working air gap formed between the permanent magnet means and the core.

Claim 5

Apparatus according to claim 1 in which the auxiliary coil is independent of the drive coil and held in a stationary position in the shell interior.

Claim 6

Apparatus according to claim 1 in which the core is a solid steel body having an outer surface, the working air gap is a void which surrounds the core and extends from the outer surface of the core to the permanent magnet means, and the width of the working air gap is just sufficient to allow passage of the drive coil between the outer surface of the core and the permanent magnet means.

Claim 7

Apparatus according to claim 5 including a cooperating shoulder and groove arrangement between the drive coil and core for producing guided movement of the drive coil along the core.

Claim 8

A permanent magnet translational motor comprising a closed steel shell having an outer wall with a pair of closed ends enclosing a hollow interior, a core comprising an elongated solid steel body extending continuously through the hollow interior of the shell from one closed end to the other, the core having an outer surface spaced from the interior of the shell outer wall, permanent magnet means located in the interior of the shell and surrounding a predetermined length of the core, the permanent magnet means being spaced from the core to form a narrow working air gap comprising a void which surrounds the core and extends from the outer surface of the core to the permanent magnet means, whereby a magnetic field is generated across the narrow working air gap, the core having a first portion of its length disposed in the working air gap and the second portion of its length adjacent to but outside of the working air gap, a movable drive coil located in the working air gap and surrounding the first portion of the core, the width of the working air gap being just sufficient to allow passage of the drive coil between the outer surface of the core and the permanent magnet means, the drive coil being connected to a first source of electrical power so it will move back and forth relative to the first portion of the core in the magnetic field in response to changes in electric current passing through it, opposed drive means extending outwardly from the drive coil through corresponding openings in the shell outer wall for attachment to a load to supply force to the load in response to movement of the drive coil, and a stationary auxiliary coil located in the interior of the shell anD wound around the second portion of the core, the auxiliary coil being adjacent to but outside of the working air gap so that the drive coil is movable toward and away from the stationary auxiliary coil, the auxiliary coil being independent of the drive coil and being connected to a second source of electrical power independent of the power source associated with the drive coil for varying the magnetic field across the working air gap in response to changes in electric current passing through the auxiliary coil to increase the maximum force which may be developed by the drive coil.

Claim 9

A permanent magnet translational motor comprising a closed steel shell having an outer wall with a pair of closed ends enclosing a hollow interior, a core comprising an elongated solid steel body extending continuously through the hollow interior of the shell from one closed end to the other, the core having an outer surface spaced from the interior of the shell outer wall, permanent magnet means located in the interior of the shell and surrounding a predetermined length of the core, the permanent magnet means being spaced from the core to form a narrow working air gap comprising a void which surrounds the core and extends from the outer surface of the core to the permanent magnet means, whereby a magnetic field is generated across the narrow working air gap, the core having a first portion of its length disposed in the working air gap and the second portion of its length adjacent to but outside of the working air gap, a movable drive coil located in the working air gap and surrounding the first portion of the core, the width of the working air gap being just sufficient to allow passage of the drive coil between the outer surface of the core and the permanent magnet means, the drive coil being connected to a first source of electrical power so it will move back and forth relative to the first portion of the core in the magnetic field in response to changes in electric current passing through it, opposed drive means extending outwardly from the drive coil through corresponding openings in the shell outer wall for attachment to a load to supply force to the load in response to movement of the drive coil, and a stationary auxiliary coil located in the interior of the shell anD wound around the second portion of the core, the auxiliary coil being adjacent to but outside of the working air gap so that the drive coil is movable toward and away from the stationary auxiliary coil, the auxiliary coil being independent of the drive coil and being connected to a second source of electrical power independent of the power source associated with the drive coil for varying the magnetic field across the working air gap in response to changes in electric current passing through the auxiliary coil to increase the maximum force which may be developed by the drive coil.

Claim 10

Apparatus according to claim 7 in which the magnetic field established by the permanent magnet means defines a closed path extending in opposite directions along the core, across the closed ends of the shell, and along the outer wall of the shell.

Claim 11

Apparatus according to claim 7 in which the drive means extend radially outwardly through corresponding longitudinally extending slotted openings in the outer wall of the shell; and including a cooperating shoulder and groove arrangement between the core and the drive coil for producing guided movement of the drive coil along the core.

Claim 12

An air delivery system for a respirator which includes a closed cylinder having a hollow interior, a piston which in normal use is movable vertically up and down in the interior of the cylinder for forcing air to a patient through an air outlet in the cylinder, and a linear drive for moving the piston, the linear drive comprising a closed steel shell adjacent the cylinder, the shell having an outer wall with a pair of closed ends enclosing a hollow interior of the shell, an elongated core extending vertically through the hollow interior of the shell from one closed end to the other, the core being a solid steel body having an outer surface spaced from the interior of the shell outer wall, permanent magnet means in the hollow interior surrounding a predetermined length of the core, the permanent magnet means being spaced from the core to form a narrow working air gap comprising a void which surrounds the core and extends from the outer surface of the core to the permanent magnet means, whereby a magnetic field is established across the narrow working air gap, a movable drive coil surrounding the portion of the core located in the working air gap, the width of the working air gap being just sufficient to allow passage of the drive coil between the outer surface of the core and the permanent magnet means, guide means for slidably engaging the drive coil with the core to allow the coil to move up and down vertically on the core and in the magnetic field in response to changes in electric current passing through the drive coil, drive means extending outwardly from the drive coil through corresponding elongated openings in the shell outer wall and connecting the piston to the drive coil to apply reciprocating translational motion to the piston in response to vertical movement of the drive coil, and an auxiliary coil located in the interior of the shell and wound around a portion of the core adjacent to but outside of the working air gap for altering the magnetic field across the working air gap in response to changes in electric current passing through the auxiliary coil to increase the maximum force which may be developed by the drive coil.

Claim 13

An air delivery system for a respirator which includes a closed cylinder having a hollow interior, a piston which in normal use is movable vertically up and down in the interior of the cylinder for forcing air to a patient through an air outlet in the cylinder, and a linear drive for moving the piston, the linear drive comprising a closed steel shell adjacent the cylinder, the shell having an outer wall with a pair of closed ends enclosing a hollow interior of the shell, an elongated core extending vertically through the hollow interior of the shell from one closed end to the other, the core being a solid steel body having an outer surface spaced from the interior of the shell outer wall, permanent magnet means in the hollow interior surrounding a predetermined length of the core, the permanent magnet means being spaced from the core to form a narrow working air gap comprising a void which surrounds the core and extends from the outer surface of the core to the permanent magnet means, whereby a magnetic field is established across the narrow working air gap, a movable drive coil surrounding the portion of the core located in the working air gap, the width of the working air gap being just sufficient to allow passage of the drive coil between the outer surface of the core and the permanent magnet means, guide means for slidably engaging the drive coil with the core to allow the coil to move up and down vertically on the core and in the magnetic field in response to changes in electric current passing through the drive coil, drive means extending outwardly from the drive coil through corresponding elongated openings in the shell outer wall and connecting the piston to the drive coil to apply reciprocating translational motion to the piston in response to vertical movement of the drive coil, and an auxiliary coil located in the interior of the shell and wound around a portion of the core adjacent to but outside of the working air gap for altering the magnetic field across the working air gap in response to changes in electric current passing through the auxiliary coil to increase the maximum force which may be developed by the drive coil.

Claim 14

Apparatus according to claim 10 in which the air outlet is located in the cylinder so that downward vertical movement of the piston in the cylinder forces air out through the air outlet.

Claim 15

Apparatus according to claim 10 in which the guide means comprises a cooperating shoulder and groove arrangement between the drive coil and the core for producing guided vertical movement of the drive coil along the core.

Claim 16

Apparatus according to claim 10 in which the core has a first portion of its length disposed in the working air gap and a second portion of its length located adjacent to but outside of the working air gap, the drive coil is located in the woRking air gap and surrounds the first portion of the core, the drive coil also being connected to a first source of electrical power and being movable back and forth relative to the first portion of the core in the magnetic field in response to changes in electrical current passing through it, the auxiliary coil is wound around the second portion of the core, the drive coil is movable toward and away from the auxiliary coil, and the auxiliary coil is connected to a second source of electrical power independent of the power source associated with the drive coil for varying the magnetic field across the working air gap.

Claim 17

Apparatus according to claim 13 in which the auxiliary coil is independent of the drive coil and is mounted in a stationary position in the shell interior.

Claim 18

Apparatus according to claim 10 in which the auxiliary coil is located at the end of the shell interior adjacent the respirator cylinder.

Claim 19

An air delivery system for a respirator which includes a closed cylinder having a hollow interior, a movable piston in the interior of the cylinder for forcing air through an air outlet in the cylinder, and a linear drive for moving the piston, the linear drive comprising a closed shell adjcent the cylinder, the shell having an outer wall with a pair of closed ends enclosing a hollow interior therein, an elongated core extending through the hollow interior of the shell from one closed end to the other, permanent magnet means in the interior of the shell surrounding a predetermined length of the core, the permanent magnet means being spaced laterally from the core to form a narrow working air gap between the permanent magnet means and the core, with a magnetic field being established across the working air gap, the core having a first portion of its length disposed in the working air gap and a second portion of its length located adjacent to but outside of the working air gap, a movable drive coil located in the working air gap and surrounding the first portion of the core, the drive coil being connected to a first source of electrical power and being movable back and forth relative to the first portion of the core in the magnetic field in response to changes in electric current passing through it, drive means extending outwardly from the drive coil through corresponding openings in the shell outer wall for attachment to the piston for applying force to the piston in response to movement of the drive coil, and an auxiliary coil located within the interior of the shell and wound around the second portion of the core such that the drive coil is movable toward and away from the auxiliary coil, the auxiliary coil being connected to a second source of electrical power independent of the power source associated with the drive coil for varying the magnetic field across the working air gap in response to changes in electric current passing through the auxiliary coil to increase the maximum force which may be applied by the drive coil to the respirator piston.

Claim 20

An air delivery system for a respirator which includes a closed cylinder having a hollow interior, a movable piston in the interior of the cylinder for forcing air through an air outlet in the cylinder, and a linear drive for moving the piston, the linear drive comprising a closed shell adjcent the cylinder, the shell having an outer wall with a pair of closed ends enclosing a hollow interior therein, an elongated core extending through the hollow interior of the shell from one closed end to the other, permanent magnet means in the interior of the shell surrounding a predetermined length of the core, the permanent magnet means being spaced laterally from the core to form a narrow working air gap between the permanent magnet means and the core, with a magnetic field being established across the working air gap, the core having a first portion of its length disposed in the working air gap and a second portion of its length located adjacent to but outside of the working air gap, a movable drive coil located in the working air gap and surrounding the first portion of the core, the drive coil being connected to a first source of electrical power and being movable back and forth relative to the first portion of the core in the magnetic field in response to changes in electric current passing through it, drive means extending outwardly from the drive coil through corresponding openings in the shell outer wall for attachment to the piston for applying force to the piston in response to movement of the drive coil, and an auxiliary coil located within the interior of the shell and wound around the second portion of the core such that the drive coil is movable toward and away from the auxiliary coil, the auxiliary coil being connected to a second source of electrical power independent of the power source associated with the drive coil for varying the magnetic field across the working air gap in response to changes in electric current passing through the auxiliary coil to increase the maximum force which may be applied by the drive coil to the respirator piston.

Claim 21

Apparatus according to claim 16 in which the core comprises a solid steel body having an outer surface, the working air gap is a void which surrounds the core and extends from the outer surface of the steel core to the permanent magnet means, and the width of the working air gap is just sufficient to allow passage of the drive coil between the outer surface of the core and the permanent magnet means.

Claim 22

Apparatus according to claim 17 including a cooperating shoulder and groove arrangement between the drive coil and the core for producing guided movement of the drive coil along the core.

Claim 23

Apparatus according to claim 16 in which the auxiliary coil is independent of the drive coil and is mounted in a stationary position in the shell interior.

Claim 24

Apparatus according to claim 16 in which the piston, in normal use, is movable vertically back and forth in the interior of the cylinder, and in which the core extends vertically through the hollow interior of the shell, the drive coil being supPorted on the core to slide vertically back and forth relative thereto to apply vertical translational motion to the piston.

Claim 25

Apparatus according to claim 20 in which the air outlet is located in the cylinder so that downward vertical movement of the piston in the cylinder forces air out through the air outlet.

Claim 26

Apparatus according to claim 20 in which the auxiliary coil is located at the end of the shell interior adjacent the respirator cylinder.

Claim 27

In an air delivery system for a respirator which includes a cylinder and a piston movable in the cylinder for forcing air to a patient through an air outlet in the cylinder, a linear drive for moving the piston, the linear drive comprising a. a shell adjacent the cylinder and having an outer wall with a pair of closed ends enclosing a hollow interior of the shell, b. an elongated core extending through the hollow interior of the shell between the closed ends thereof, the core consisting essentially of a ferromagnetic material having an outer surface thereof spaced from the interior of the shell outer wall, c. permanent magnet means in the hollow interior surrounding a predetermined length of the core, the permanent magnet means being spaced from the core to form a narrow working air gap comprising a void which surrounds the core and extends from the outer surface of the core to the permanent magnet means, whereby a magnetic field is established across a narrow working air gap, d. a movable drive coil surrounding the portion of the core located in the working air gap, the width of the working air gap being just sufficient to allow passage of the drive coil between the outer surface of the core and permanent magnet means, the drive coil being movable along the length of the core in the magnetic field in response to changes in electric current passing through the drive coil, e. drive means extending outwardly from the drive coil through corresponding elongated openings in the shell outer wall and connecting the piston to the drive coil to apply a reciprocating translational motion to the piston in response to movement of the drive coil, and f. an auxiliary coil located in the interior of the shell and wound around the portion of the core adjacent to but outside of the working air gap for altering the magnetic field across the working air gap in response to changes in electric current passing through the auxiliary coil to increase the maximum force which may be developed by the drive coil.

Claim 28

In an air delivery system for a respirator which includes a cylinder and a piston movable in the cylinder for forcing air to a patient through an air outlet in the cylinder, a linear drive for moving the piston, the linear drive comprising a. a shell adjacent the cylinder and having an outer wall with a pair of closed ends enclosing a hollow interior of the shell, b. an elongated core extending through the hollow interior of the shell between the closed ends thereof, the core consisting essentially of a ferromagnetic material having an outer surface thereof spaced from the interior of the shell outer wall, c. permanent magnet means in the hollow interior surrounding a predetermined length of the core, the permanent magnet means being spaced from the core to form a narrow working air gap comprising a void which surrounds the core and extends from the outer surface of the core to the permanent magnet means, whereby a magnetic field is established across a narrow working air gap, d. a movable drive coil surrounding the portion of the core located in the working air gap, the width of the working air gap being just sufficient to allow passage of the drive coil between the outer surface of the core and permanent magnet means, the drive coil being movable along the length of the core in the magnetic field in response to changes in electric current passing through the drive coil, e. drive means extending outwardly from the drive coil through corresponding elongated openings in the shell outer wall and connecting the piston to the drive coil to apply a reciprocating translational motion to the piston in response to movement of the drive coil, and f. an auxiliary coil located in the interior of the shell and wound around the portion of the core adjacent to but outside of the working air gap for altering the magnetic field across the working air gap in response to changes in electric current passing through the auxiliary coil to increase the maximum force which may be developed by the drive coil.