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AssigneeThe Singer Company
InventorsJohn Addison Herr, Wolfgang Jaffe, Allan Matthew Dob, Philip Francis Minalga, Kenneth Douglas Adams, William Lee Herron
Estimating the term…
A linear motor for use, for example, in sewing machines for controlling needle vibration as to amplitude and/or fabric feed both in magnitude and direction, said motor comprising a frame having an internal central pole piece spaced intermediate two permanent magnets of the high energy product type which are attached to the frame, the central pole piece providing supporting means for movable coil member integrally formed with connecting arms pivotally fastened to an actuator arm carried on a pivoted potentiometer shaft. The permanent magnets are secured through their own magnetism to the frame and are each locked in proper orientation by a non-metallic retainer which is locked to the magnet and additionally formed with a closure panel, said closure panels cooperating with the motor frame completely to enclose a compartment for the movable coil member effecting both a minimum external leakage field and a dust proof unit.
A linear motor comprising a ferro-magnetic metal frame including a opposed set of front and rear walls joined by an opposed set of end walls together defining a enclosure, a non-circular ferro-magnetic pole piece spanning one of said sets of opposed frame walls within said enclosure, a bobbin formed of non-magnetizable material arranged freely slidable on said pole piece within said enclosure, wire wound in a coil on said bobbin to a depth of a plurality of wire diameters, a motor output arm connected to said bobbin and extending out through a clearance aperture in said motor frame enclosure, a block of permanently magnetized material in the shape of a parallelepiped of substantially uniform thickness dimension insertible with clearance within said enclosure in the space between said pole piece and a wall of said motor frame with the uniform thickness dimension being arranged extending between said frame wall and said pole piece, and holding means formed of non-magnetic material for constraining said block of permanently magnetized material in a position against said motor frame wall so as to locate all of said clearance between the pole piece and said block of permanently magnetized material.
A linear motor comprising a ferro-magnetic metal frame including an opposed set of front and rear walls joined by an opposed set of end walls together defining an enclosure, a non-circular ferro-magnetic pole piece spannig one of said sets of opposed framewalls within said enclosure, a bobbin formed of non-magnetizable material arranged freely slidable on said pole piece within said enclosure, wire wound in a coil on said bobbin to a depth of a plurality of wire diameters, a motor output arm connected to said bobbin and extending out through a clearance aperture in said motor frame enclosure, a block of permanently magnetized material insertible with clearance within said enclosure in the space between said pole piece and a wall of said motor frame, and a holder member formed of non-magnetic material fitted together with said block of permanently magnetized material in the space between pole piece and said motor frame wall for constraining said block of permanently magnetized material in position against said motor frame wall so as to locate all of said clearance between the pole piece and said block of permanently magnetized material.
Dependencies are inferred from the claim text.