Magnetic linear motor

Claim 1

A magnetic linear motor assembly (10) comprising; a platen defining a planar surface presenting a grid of magnetic (12) and nonmagnetic (14) zones spaced from one another along an axis (A) of relative movement a distance pn where n is any whole number and p is the pitch of the grid as defined by the distance between center lines of next adjacent magnetic zones (12) or of next adjacent nonmagnetic zones (14), a head (22) movable along said axis (A) over said platen, said head (22) including a first plurality (24) of U-shaped laminations extending transversely to said axis (A) and disposed on adjacent centerlines spaced p(n±1/2) apart with the lower extremity of one leg (26, 28') of each lamination being shorter than the other long leg (26', 28) so as to be spaced farther above said magnetic zones (12) of said platen and with each short leg (26, 28') being sandwiched between the axially aligned long legs (26, 28') of the next adjacent laminations so that the first legs (26, 26') of said laminations are alternately short and long and the second legs (28, 28') of said laminations are alternately short and long, said head including a second plurality (30) of U-shaped laminations extending transversely to said axis (A) of movement and disposed on adjacent centerlines spaced p(n+1/2) apart with the lower extremity of one leg (26, 28') of each lamination being shorter than the other long leg (26', 28) thereof so as to be spaced farther above said magnetic zones (12) of said platen and with each short leg (26, 28') being sandwiched between the axially aligned long legs (26', 28) of the next adjacent laminations so that the first legs (26, 26') of said second plurality of laminations (30) are alternately short and long as are the second legs (28, 28') thereof, said laminations of said first plurality (24) being transversely aligned with the laminations (26, 26') of said second plurality (30) and with said first (26, 26') and second (28, 28') legs thereof being alternately short and long across aligned laminations of said first and second pluralities (24, 30) aligned transversely of said axis (A) of movement, said head (22) including a third plurality (32) of U-shaped laminations extending transversely to said axis (A) of movement and disposed on adjacent centerlines spaced p(n±1/2) apart with the lower extremity of one leg (26, 28') of each lamination being shorter than the other long leg (26, 28') thereof so as to be spaced farther above said magnetic (26, 28') zones (12) of said platen and with each short leg (26, 28') being sandwiched between the axially aligned long legs (26', 28) of the next adjacent laminations to that the first legs (26, 26') of said third plurality (32) of laminations are alternately short and long as are the second legs (28, 28') thereof, said head (22) including a fourth plurality (34) of U-shaped laminations extending transversely to said axis (A) of movement and disposed on adjacent centerlines spaced p(n±1/2) apart with the lower extremity of one leg (26, 28') of each lamination being shorter than the other long leg (26', 28) thereof so as to be spaced farther above said magnetic zones (12) of said platen and with each short leg (26, 28') being sandwiched between the axially aligned long legs (26', 28) of the next adjacent laminations so that the first legs (26, 26') of said fourth plurality (34) of laminations are alternately short and long as are the second legs (28, 28') thereof, said laminations of said third plurality (32) being transversely aligned with the laminations of said fourth plurality (34) and with said first (26, 26') and second (28, 28') legs thereof being alternately short and long across aligned laminations of said third (32) and fourth (34) pluralities aligned transversely of said axis (A) of movement, first bias magnet means (36) establishing magnetic flux for polarizing said first (26, 26') and second (28, 28') legs of said first plurality (24) of laminations (26, 26') in opposite polarity to said first (26, 26') and second (28, 28') legs of said second plurality (30) of laminations, second bias magnet means (36') establishing magnetic flux for polarizing said first (26, 26') and second (28, 28') legs of said third plurality (32) of laminations in opposite polarity to said first (26, 26') and second (28, 28') legs of said fourth plurality (34) of laminations, first winding means (38) looped between the first (26, 26') and second (28, 28') legs of said first plurality (24) of laminations for reinforcing the flux in axially aligned first legs (26, 26') while opposing the flux in the other axially aligned second legs (28, 28') of said first plurality (24) of laminations and looped between the first (26, 26') and second (28, 28') legs of said second plurality (30) of laminations for reinforcing the flux in the axially aligned first legs (26, 26') while opposing the flux in the other axially aligned second leg (28, 28') of said second plurality (30) of laminations, and vice versa, depending upon the direction of electrical current flow in said first winding means (38), and second winding means (40) looped between said first (26, 26') and second (28, 28') legs of said third plurality (32) of laminations for reinforcing the flux in axially aligned first legs (26, 26') while opposing the flux in the other axially aligned second legs (28, 28') of said third plurality (32) of laminations and looped between said first (26, 26') and second (28, 28') legs of said fourth plurality (34) of laminations for reinforcing the flux in the axially aligned first legs (26, 26') while opposing the flux in the other axially aligned second legs (28, 28') of said fourth plurality (34) of laminations, and vice versa, depending upon the direction of electrical current flow in said second winding means (40) so that when said first (24) and second (30) plurality of laminations are axially aligned with and transversely overlying said magnetic zones (12) and said third (32) and fourth (34) plurality of laminations are axially offset p(n±1/4) and transversely overlapping said magnetic (12) and nonmagnetic (14) zones, said long legs (28) of said second legs (28, 28') of each of said third (32) and fourth (34) plurality of laminations coact with the underlying magnetic zones (12) in response to current flow in said second winding means (40) in loop direction one (clockwise) to move said head (22) axially in one direction and said long legs (26') of said first legs (26, 26') of each of said third (32) and fourth (34) plurality of laminations coact with the underlying magnetic zones (12) in response to current flow in said second winding means (40) in loop direction two (counterclockwise opposite to direction one to move said head (22) axially in the opposite direction at which position current flow in said first winding means (38) in loop direction one causes said long legs (26') of said first legs (26, 26') of each of said first (24) and second (30) plurality of laminations to coact with the underlying magnetic zones (12) to move said head (22) axially in one direction or alternatively current flow in said first winding means (38) in loop direction two opposite to direction one causes said long legs (28) of said second legs (28, 28') of each of said first (24) and second (30) plurality of laminations to coact with the underlying magnetic zones (12) to move said head (22) axially in the opposite direction.