Patent ID: 11915863
Assignee: ZABER TECHNOLOGIES INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 45:
46. A constant-force apparatus comprising:
a first part,
a second part movable in a direction of motion relative to the first part,
a first permanent magnet assembly carried by the first part and comprising a first array of permanent magnets arranged to form a multipolar magnet array comprising a plurality of magnetic poles, the magnetic poles extending in the direction of motion,
wherein the permanent magnets of the first array have polarizations directed in a first transverse direction transverse to the direction of motion, the polarization of the permanent magnets of the first array is substantially uniform along the direction of motion and the polarization of the permanent magnets of the first array alternates in orientation along the first transverse direction at regular intervals along a second transverse direction orthogonal to the direction of motion and the first transverse direction when the first array of permanent magnets is traversed in the second transverse direction,
a second permanent magnet assembly carried by the second part and comprising a second array of permanent magnets arranged to form a multipolar magnet array comprising magnetic poles extending in the direction of motion, wherein the permanent magnets of the second array have a polarization that is substantially aligned with the first transverse direction and a number of the magnetic poles in the first and second arrays are equal,
wherein the polarization of the permanent magnets of the second array is substantially uniform along the direction of motion and the polarization of the permanent magnets of the second array alternates in orientation along the first transverse direction at regular intervals along the second transverse direction when the second array of permanent magnets is traversed in the second transverse direction,
wherein the first part and the second part are constrained to move relative to each other in the direction of motion within a fixed range of travel and the magnetic poles of the first and second arrays extend in the direction of motion for a distance at least equal to the range of travel;
wherein the magnets of the first array are spaced apart from the magnets of the second array in the first transverse direction by a first gap having a width of 5 mm or less and the first array is supported relative to the second array located such that throughout the entire range of travel, at least a portion of the first array overlaps in the direction of motion with a corresponding portion of the second array.