Maintenance station of ink jet printer and cap and pump included therein

A maintenance station for use in an ink jet printer to perform a maintenance recovery operation on an ink jet head thereof, said maintenance station comprising:

• a cap to achieve capping of at least one nozzle hole of the ink jet head;
• a pump including a casing having therein a cylindrical guide opening, a cylinder comprising a cylindrical member mounted in said cylindrical guide opening, said cylindrical member having therethrough a cylindrical passage, and a piston movable in opposite directions in said cylindrical passage for suction and compression strokes;
• separate suction and discharge holes in said pump;
• a power source;
• and
• a piston drive operably connected to said power source and to said piston to move said piston in said opposite directions in said cylindrical passage, to connect a pressure chamber in said pump via said suction hole to said cap during said suction stroke, and to connect said pressure chamber via said discharge hole to the exterior during said compression stroke.

A pump to be employed in a maintenance station of an ink jet printer, said pump comprising:

• a casing having therein a cylindrical guide opening having a first axis, and suction and discharge ports leading from said cylindrical guide opening;
• a cylindrical member mounted in said cylindrical guide opening and rotatable therein in opposite directions about said first axis, said cylindrical member having therethrough a cylindrical passage having a second axis;
• a piston extending into said cylindrical passage and defining therein a pressure chamber;
• and
• said piston being movable in said cylindrical passage in opposite directions along said second axis, thereby performing suction and compression strokes, and said piston being pivotable in opposite directions transverse to said second axis and thereby reciprocally rotating said cylindrical member in said opposite directions about said first axis.

A method of operating a maintenance station to perform a maintenance recovery operation on an ink jet head of an ink jet printer, said maintenance station including a cap to achieve capping of at least one nozzle hole of said ink jet head, a cap holder mounted for movement toward and away from said ink jet head, said cap holder supporting said cap at a position to cap said at least one nozzle hole when said cap holder is moved toward said ink jet head and to release capping when said cap holder is moved away from said ink jet head, a pump within said cap holder and including a cylindrical guide opening formed in said cap holder, a cylindrical member mounted in said cylindrical guide opening, said cylindrical member having therethrough a cylindrical passage defining a pressure chamber, and a piston slidable in opposite directions within said cylindrical passage for suction and compression strokes of said pump, separate suction and discharge holes in said pump, a power source, and a piston drive operably connected to said power source and to said piston to move said piston in said opposite directions in said cylindrical passage to connect said pressure chamber in said cylindrical passage via said suction hole to said cap during said suction stroke, and to connect said pressure chamber via said discharge hole to the exterior during said compression stroke, said method comprising:

• moving said cap holder toward said ink jet head to a capping position with said cap capping said at least one nozzle hole;
• conducting said suction stroke with said cad holder in said capping position, and thereby drawing residual ink from said ink jet head into said pressure chamber through said suction hole;
• conducting said compression stroke with said cap holder in said capping position, and thereby discharging said residual ink from said pressure chamber through said discharge hole to the exterior;
• moving said cap holder away from said ink jet head to an intermediate position with a gap between said cap and said ink jet head;
• conducting said suction stroke with said cap holder at said intermediate position, and thereby drawing air from said gap and ink from the surface of said at lest one nozzle hole into said pressure chamber through said suction hole;
• conducting said compression stroke with said cap holder in said intermediate position, and thereby discharging said air and ink from said pressure chamber through said discharge hole to the exterior;
• and
• moving said cap holder further away from said ink jet head to a withdrawn position whereat said cap is spaced further away from said ink jet head.