초록

A method of and apparatus for changing the magnetic forces generated by and between a pair of magnetic assemblies spaced apart along a given path, by selectively positioning these fields with respect to each other.

대표청구항 ▼

A magnetic apparatus comprising: first and second means aligned in and spaced apart along a given direction and being operable for establishing first and second magnetic fields having predetermined strengths with like poles facing each other along said given direction; and said first means including

A magnetic apparatus comprising: first and second means aligned in and spaced apart along a given direction and being operable for establishing first and second magnetic fields having predetermined strengths with like poles facing each other along said given direction; and said first means including magnetically permeable material having a distal end face in facing relation to an opposed end face of said second means, said material having a given permeability and relatively easily demagnetizable relative to said fields and being of short enough length which, when said second means is in remote proximity to said material, will permit the magnetic field of said first means to extend at least to said distal end face of said material and of great enough length which, when said second means is in close proximity to said material, will permit substantially all of the magnetic field of said first means to pass through side surfaces of said material whereby as the distance along said given direction between said first and second means is varied, an attractive force exists between said second means and said material when said end face of said second means is within a given distance of said distal end of said material and a repulsive force exists when said end face of said second means is greater than said given distance.