Printer system

A dot matrix printer for printing characters in character positions on a paper web comprising:

• a hammer bank disposed adjacent and transverse to the paper web, the hammers each including dot printer elements and the hammer bank including means for actuating the hammers;
• means coupled to said hammer bank for cyclically moving said hammer bank, including said means for actuating the hammers, across a selected number of character positions, said means for cyclically moving including counterweight means for dynamically counterbalancing the mass of said hammer bank and said means for actuating;
• and
• means coupled to said actuating means and responsive to the position of said means for cyclically moving for actuating said hammers during movement of said hammer bank.

In a printer for printing characters in separate column and row character positions each defined by a pattern of dots in dot matrix column and row positions on a web member, said printer including means for advancing said web members as characters are printed, the improvement comprising:

• a shuttle mechanism movable in the row direction;
• a plurality of hammers mounted on said shuttle mechanism, each adjacent said web member and each including a dot imprinting means;
• a platen disposed on the opposite side of said web member and opposed to said dot imprinting means;
• means coupled to said shuttle mechanism for cyclically moving said shuttle mechanism and said hammers bidirectionally along the row direction such that each hammer spans at least one character column position during its travel;
• a plurality of magnetic means having a common magnetic member mounted on said shuttle mechanism and movable therewith and each coupled to control a different one of said hammers;
• and means for energizing said magnetic means to cause independent imprinting movements of said hammers during travel of said shuttle mechanism in each direction of movement.

A dot printing mechanism for a dot matrix printer comprising:

• an elongated resilient strip of magnetic material disposed substantially tangential to a printing position adjacent a movable end thereof;
• a dot printer head coupled to said resilient strip and extending toward the printing position;
• magnetic path means coupled to the end of said strip spaced apart from the printing position and defining a magnetic path including a pole tip adjacent the movable end of the strip;
• permanent magnet means disposed adjacent said strip in circuit with said magnetic path means and normally retracting said strip against said pole tip in curved, spring-loaded, position and with the dot printer head disposed in spaced apart position relative to the printing position;
• and
• electromagnetic means coupled to said magnetic path means for abruptly removing the magnetic bias on said strip to impel said dot printer head under the spring force of said strip toward the printing position.

A multiple hammer bank for a dot printer comprising:

• a plurality of elongated, flat, substantially parallel, magnetic, spring hammer elements disposed in serial fashion along a selected axis in a selected plane and having free ends adjacent a printing line, each hammer including a dot printing element;
• magnetic circuit means, including a common magnetic return path member, forming a plurality of substantially complete magnetic paths with said different hammer elements, said magnetic circuit means including a plurality of magnetic pole pieces disposed substantially normal to said selected plane and each in facing relation to the free end of a different hammer element;
• means coupled to said magnetic circuit means for magnetically biasing said hammer elements into engagement with its associated pole piece in the absence of a release impulse, to define a spring-loaded retract position;
• and means coupled to each of said magnetic circuit means for selectively applying release impulses thereto to momentarily overcome the magnetic bias.

A dot matrix printing system for printing on a web comprising the combination of:

• a shuttle mechanism transversely reciprocally movable in a cyclic motion relative to said web;
• rotatable cam drive means coupled to said shuttle mechanism to provide the reciprocating motion thereto;
• counterweight means substantially equal in mass to said shuttle mechannism and including cam follower means engaging said cam drive means and coupled to move oppositely to said shuttle mechanism;
• a plurality of print hammers including dot printing elements mounted on said shuttle mechanism;
• means coupled to said print hammers for initiating high velocity movement of said hammers toward said web during transverse motion of said shuttle mechanism;
• and
• means for advancing said web along its length in timed relation to the cyclic motion of said shuttle mechanism.

A system for control of the disposition of an arbitrary number of paper webs at the printing line position of a multi-column dot matrix printer comprising:

• means disposed below the printing line position for providing a desired number of webs for imprinting;
• a cylindrical platen disposed behind the paper and parallel to the printing line position, said cylindrical platen being pivotably mounted at opposite ends adjacent the opposite sides of the paper and along an axis substantially parallel to the printing line position, and having radial eccentricity relative to its rotational axis, said platen being pivotable to a selectable position to define a platen surface for receiving the impact of dot imprinting elements that is substantially normal to the movement of the dot imprinting elements but at variable spacings therefrom dependent on the pivot position thereof;
• a plurality of finger elements disposed on the opposite side of said webs from the cylindrical platen, said finger elements being fixedly mounted along a base substantially parallel to the printing line position and the free ends of the finger elements urging said paper webs toward and into engagement with said cylindrical platen;
• and means for pivoting said cylindrical platen to thereby change the position of the platen surface relative to the printing line position and said finger elements to provide substantially constant tension independent of total web thickness.