Patent ID: 6930411

Claim:
Essentially iron-free linear motor ( 1 ) for a sewing device or sewing machine to produce and control the pressure on the material being sewn by means of a drive rod ( 10 ), with a tubular housing ( 12 ), with at least two annular permanent magnets ( 11 a , 11 b ) located therein, said magnets each having a north pole and a south pole and being magnetized radially, each in a different magnetization direction, and with a coil ( 14 ) divided into at least two partial coils ( 14 a , 14 b ) wound in opposite directions and each associated with a permanent magnet, whereby said partial coils and the permanent magnets are mutually displaceable, involving drive rod ( 10 ), in a magnetic lock that is effected by the housing ( 12 ), by a core in the form of center piece ( 13 ), and an air gap with the coil ( 14 ), characterized in that partial coils ( 14 a , 14 b ) are located inside housing ( 12 ) and that permanent magnets ( 11 a , 11 b ) are located between said coils and the center piece ( 13 ).