Printing apparatus

1. A rotary printing apparatus comprising:

a plurality of printing stations; and

an interchangeable pallet unit having a longitudinal axis and slidably adjustable along a rotary screen printing arm rotatable to the plurality of printing stations including:

a pallet;

a mounting mechanism positioned and configured to operatively connect the interchangeable pallet unit to a mounting arm operatively connected to the rotary screen printing arm, and

a movement mechanism operatively connected to the mounting mechanism and to the pallet so as to allow movement of the pallet in directions transverse to the longitudinal axis and in directions along the longitudinal axis, wherein the pallet is slidably adjustable along the longitudinal axis;

an indexing mechanism operatively connected to the mounting arm and positioned so as to permit indexed movement of the pallet in directions transverse to the longitudinal axis and relative to the mounting arm; and

an adjustable bar unit operatively connectable to the mounting arm configured to receive a printing screen and hold the printing screen in a printing location.

2. A rotary printing apparatus according to claim 1 , further including a tilting mechanism operatively connected to the interchangeable pallet unit and to the indexing mechanism so as to allow the interchangeable pallet to move relative to the indexing mechanism.

3. A rotary printing apparatus according to claim 1 , wherein the indexing mechanism including an index point and a series of index stops.

4. A rotary printing apparatus according to claim 1 , further comprising a rack unit operatively connected to the adjustable bar unit and including a plurality of slots for storing a plurality of printing screens.

5. A printing apparatus according to claim 1 wherein the adjustable bar unit includes an off contact adjustment rod, one or more front adjustment bars, and a rear off contact adjustment bar.

6. A method of printing on a medium using an apparatus operatively connectable to a mounting arm, comprising:

positioning an interchangeable pallet unit having a longitudinal axis on the mounting arm operatively connected to a rotary screen printing arm, wherein the rotary screen printing arm is operatively connected to a rotary printing apparatus including a plurality of printing stations, wherein the rotary screen printing arm is rotatable to the plurality of printing stations;

positioning the interchangeable pallet using an indexing mechanism operatively connected to the mounting arm, at a first desired index stop by moving the interchangeable pallet in a first direction transverse to the longitudinal axis and relative to the mounting arm;

slidably adjusting the interchangeable pallet along the longitudinal axis to a first desired position;

positioning an adjustable bar unit to receive a printing screen, the adjustable bar unit configured to hold the printing screen in a printing location;

using the printing screen to print;

positioning the interchangeable pallet using an indexing mechanism operatively connected to the mounting arm, at a second desired index stop by moving the interchangeable pallet in a second direction transverse to the longitudinal axis and relative to the mounting arm;

slidably adjusting the interchangeable pallet along the longitudinal axis to a second desired position;

re-positioning the adjustable bar unit to receive the printing screen; and

using the printing screen to print.

7. A method according to claim 6 wherein the adjustable bar unit includes an off contact adjustment rod, one or more front adjustment bars, and a rear off contact adjustment bar.

8. A printing apparatus operatively connectable to a mounting arm having a longitudinal axis and an axis transverse to the longitudinal axis, comprising:

a mounting apparatus configured to be fixedly connected to the mounting arm operatively connected to a rotary screen printing arm, wherein the rotary screen printing arm is operatively connected to a rotary printing apparatus including a plurality of printing stations, wherein the rotary screen printing arm is rotatable to the plurality of printing stations;

a pallet movably connected to the mounting apparatus so as to be movable in first and second directions along an axis parallel to the transverse axis and movable in first and second directions along an axis parallel to the longitudinal axis;

an index mechanism including a plurality of index stops respectively corresponding to a plurality index positions of the pallet, and being fixedly connected with respect to the mounting apparatus so as to selectively engage the pallet at a desired one of the index positions, wherein the plurality of index positions extend in directions parallel to the transverse axis; and

an adjustable bar unit operatively connectable to the mounting arm configured to receive a printing screen and to hold the printing screen in a printing location.

9. A printing apparatus according to claim 8 , wherein the mounting apparatus is configured to be removably connected to the mounting arm.

10. A printing apparatus according to claim 8 , wherein the index mechanism is fixedly connected to the mounting apparatus.

11. A printing apparatus according to claim 8 wherein the adjustable bar unit includes an adjusting mechanism positioned to allow movement of the printing screen relative to the longitudinal axis and the transverse axis.

12. A printing apparatus according to claim 8 , further comprising a rack unit operatively connected to the adjustable bar unit and including a plurality of slots for storing a plurality of printing screens.

13. A printing apparatus according to claim 8 , wherein the adjustable bar unit includes an off contact adjustment rod, one or more front adjustment bars, and a rear off contact adjustment bar.