Counterbalanced bidirectional shuttle drive having linear motor

A linear motor arrangement comprising the combination of an element of magnetic material, means mounting the element of magnetic material to provide reciprocating linear motion of the element of magnetic material along a path of movement, a magnetic circuit having a first pair of spaced-apart pole pieces disposed adjacent the element of magnetic material, means coupled to the magnetic circuit for providing a flow of magnetic flux through a first one of the first pair of spaced-apart pole pieces, a pair of coils mounted on the element of magnetic material and each being disposed adjacent a different one of the first pair of spaced-apart pole pieces, means defining opposite limits of the linear motion of the element of magnetic material and disposed to be impacted each time the element of magnetic material reaches one of the opposite limits of the linear motion, a member of magnetic material having a second pair of spaced-apart pole pieces disposed adjacent the element of magnetic material with each of the second pair of spaced-apart pole pieces being disposed on an opposite side of the element of magnetic material from a different one of the first pair of pole pieces, and wherein the means for providing a flow of magnetic flux includes a pair of permanent magnets disposed on opposite sides of the element of magnetic material, one of the permanent magnets being coupled to one of the first pair of pole pieces and the other one of the permanent magnets being coupled to one of the second pair of pole pieces.

A linear motor arrangement comprising the combination of:

• a pair of spaced-apart rotatable elements;
• an elongated element extending between and disposed adjacent the rotatable elements;
• magnetic pole piece means disposed adjacent and forming an air gap with the elongated element on the same side of the elongated element as the rotatable elements;
• magnet means coupled to the pole piece means to magnetically attract the elongated element toward the pole piece means to hold the elongated element adjacent each of the pair of spaced-apart rotatable elements;
• a coil mounted on the elongated element within the air gap;
• and
• means for applying a current to the coil to reciprocate the elongated element and rotate the pair of spaced-apart rotatable elements.

An arrangement for bidirectionally driving a printing mechanism relative to a printable medium in a line printer comprising the combination of:

• a pair of circular elements mounted in spaced-apart relation for rotation about a pair of generally parallel axes;
• an elongated printing mechanism including a mounting element of magnetic material extending between the circular elements on one side of the circular elements;
• an elongated counterbalancing element of magnetic material extending between the circular elements on the other side of the circular elements;
• a first pole piece disposed between the pair of circular elements and forming an air gap with the elongated printing mechanism;
• a magnet coupled to a portion of the first pole piece opposite the elongated printing mechanism and forming an air gap with the counterbalancing element;
• a second pole piece disposed between the pair of circular elements and spaced-apart from the first pole piece, the second pole piece forming air gaps with the elongated printing mechanism and the counterbalancing element;
• a first coil mounted on the counterbalancing element and disposed within the air gap formed by the magnet with the counterbalancing element;
• and
• a second coil mounted on the counterbalancing element and disposed within the air gap formed by the second pole piece with the counterbalancing element.

An arrangement for bidirectionally driving a printing mechanism relative to a printable medium in a line printer comprising the combination of:

• a pair of circular elements mounted in spaced-apart relation for rotation about a pair of generally parallel axes;
• an elongated printing mechanism including a mounting element of magnetic material extending between the circular elements on one side of the circular elements;
• an elongated counterbalancing element of magnetic material extending between the circular elements on the other side of the circular elements;
• a first pole piece disposed between the pair of circular elements and forming an air gap with the mounting element of the elongated printing mechanism;
• a first magnet coupled to a portion of the first pole piece opposite the elongated printing mechanism and forming a first air gap with the counterbalancing element;
• a second pole piece disposed between the pair of circular elements and spaced-apart from the first pole piece, the second pole piece forming an air gap with the mounting element of the elongated printing mechanism and a second air gap with the counterbalancing element;
• a third pole piece disposed on the opposite side of the counterbalancing element from the first and second pole pieces, the third pole piece having a first end thereof forming a third air gap with the counterbalancing element opposite the second air gap;
• a second magnet coupled to a second end of the third pole piece opposite the first end of the third pole piece and forming a fourth air gap with the counterbalancing bar opposite the first air gap;
• a first coil mounted on the counterbalancing element and disposed within the first and fourth air gaps, and
• a second coil mounted on the counterbalancing element and disposed within the second and third air gaps.

A linear motor arrangement comprising the combination of:

• a pair of opposite rotatable elements;
• first and second elongated elements extending between the pair of opposite rotatable elements on opposite sides of the pair of opposite rotatable elements, each of the first and second elongated elements undergoing linear motion along a different path of movement upon rotation of the pair of opposite rotatable elements;
• a resilient stop mechanism disposed adjacent a first one of the pair of opposite rotatable elements and extending into the different path of movement for each of the first and second elongated elements;
• a band having an integral central portion between an opposite pair of end portions, the central portion of the band extending around and being attached at a first location to the first one of the pair of opposite rotatable elements, the central portion of the band being attached at a second location to the first elongated element and being attached at a third location to the second elongated element, a first one of the opposite pair of end portions extending from the second location at least partly around and being attached to the second one of the pair of opposite rotatable elements and the second one of the opposite pair of end portions extending from the third location at least partly around and being attached to the second one of the pair of opposite rotatable elements;
• a resilient element mounted within the second one of the pair of opposite rotatable elements and extending into contact with one of the opposite pair of end portions of the band;
• and
• means for bidirectionally driving the pair of opposite rotatable elements and the first and second elongated elements to reciprocate the first and second elongated elements along the different paths of movement therefor.

An arrangement for bidirectionally driving a hammer bank shuttle assembly along a linear path comprising the combination of:

• a pair of opposite rotatable elements;
• a first elongated element forming a hammer bank shuttle assembly mounting element and extending between and adjacent each of the pair of opposite rotatable elements on one side of the rotatable elements;
• a second elongated element forming a counterbalancing element and extending between and adjacent each of the pair of opposite rotatable elements on the opposite side of the rotatable elements from said one side;
• a first magnetic member disposed adjacent one of the first and second elongated elements;
• a second magnetic member mounted on said one of the first and second elongated elements;
• and
• means for providing to one of the first and second magnetic members a cyclically varying signal to cause the first and second magnetic members to magnetically interact and provide reciprocation of the first and second elongated elements in opposite directions through a path of linear movement.

A linear motor arrangement comprising the combination of:

• a pair of spaced-apart rotatable elements;
• an elongated element extending between and disposed adjacent the rotatable elements;
• first and second magnets mounted in spaced-apart relation along the length of the elongated element;
• first and second coils disposed adjacent and forming air gaps with the first and second magnets respectively;
• and
• means for applying to the first and second coils a cyclically varying signal to reciprocate the elongated element in opposite directions through a path of linear movement.