Print head gap adjustment mechanism with skew compensation

A print head for printing characters on a record medium;

• first and second spaced apart side walls, said second wall having first and second apertures extending therethrough;
• a first eccentric member rotatably mounted in said first side wall;
• a platen for supporting said record medium located between said side walls;
• a guide rod and a guide rail located between said side walls and positioned substantially parallel to said platen for slidably supporting said print head across said record medium, said print head having a first opening through which said guide rod passes and having an elongated second opening which slidably accommodates said guide rail;
• an elongated plate pivotally mounted on the outside surface of said second side wall;
• second and third eccentric members rotatably mounted in said plate;
• said guide rod passing through said first aperture in said second wall having its ends secured to said first and second eccentric members respectively;
• a pull-back lever for varying the distance between the print head and the platen said lever being secured to said first eccentric member for rotation therewith;
• a copy lever including a camming surface rotatably mounted on the outside surface of said first side wall;
• a spring for biasing said pull-back lever towards said camming surface establishing a printing gap between said print head and said platen;
• and
• a compensator rod for sensing and compensating for skewing which may occur between said side walls, said compensator rod located substantially below said first guide rod and being rotatably supported in said second aperture of said side wall, said compensator rod having one of its ends secured to said first side wall and having its other end secured to said third eccentric member.

A serial printer comprising:

• a print head for printing characters on a record medium;
• first and second spaced apart side walls;
• a platen for supporting said record medium located between said side walls;
• means for slidably supporting said print head across said record medium;
• means for establishing and varying a printing gap between said print head and said platen;
• and
• means for sensing and compensating for skewing which may occur between said side walls when said printer is positioned on an uneven surface.