Self-cleaning ink jet printer and method of assembling same

A self-cleaning printer, comprising:

• (a) a print head having a surface having contaminant thereon;
• (b) a cleaning assembly disposed relative to the surface for directing a flow of fluid along the surface to clean the contaminant from the surface, said assembly including a septum disposed opposite the surface for defining a gap therebetween sized to allow the flow of fluid through the gap, said septum accelerating the flow of fluid to induce a hydrodynamic shearing force in the flow of fluid, whereby the shearing force acts against the contaminant while the shearing force is induced in the flow of fluid and whereby the contaminant is cleaned from the surface while the shearing force acts against the contaminant;
• and
• (c) a piston arrangement in fluid communication with the gap for generating a pressure wave in the flow of fluid to enhance cleaning of the contaminant from the surface.

A self-cleaning printer, comprising:

• (a) a print head movable from a first position to a second position thereof, said print head having a surface defining an orifice therethrough, the orifice having particulate matter obstructing the orifice;
• (b) a cleaning assembly disposed proximate the surface for directing a flow of liquid along the surface and across the orifice to clean the particulate matter from the orifice while said print head is at the second position thereof, said assembly including:
• (i) a cup scalingly surrounding the orifice, said cup defining a cavity therein;
• (ii) an elongate septum disposed in said cup perpendicularly opposite the orifice for defining a gap between the orifice and said septum, the gap sized to allow the flow of liquid through the gap, said septum dividing the cavity into an inlet chamber and an outlet chamber each in communication with the gap, said septum accelerating the flow of liquid to induce a hydrodynamic shearing force in the flow of liquid, whereby the shearing force acts against the particulate matter while the shearing force is induced in the flow of liquid, whereby the particulate matter is cleaned from the orifice while the shearing force acts against the particulate matter and whereby the particulate matter is entrained in the flow of liquid while the particulate matter is cleaned from the orifice;
• (iii) a pump in fluid, communication with the outlet chamber for pumping the liquid and entrained particulate matter from the gap and into the outlet chamber;
• (c) a transport mechanism connected to said print head for moving said print head from the first position to the second position thereof;
• (d) a controller connected to said transport mechanism, said cleaning assembly and said print head for controlling operation thereof;
• and
• (e) a reciprocating piston in fluid communication with the inlet chamber for generating a plurality of pressure waves in the flow of liquid to enhance cleaning of the particulate matter from the orifice.

A self-cleaning printer, comprising:

• (a) a print head movable from a first position to a second position thereof, said print head having a surface defining an orifice therethrough, the orifice having particulate matter obstructing the orifice;
• (b) a cleaning assembly disposed proximate the surface for directing a flow of liquid along the surface and across the orifice to clean the particulate matter from the orifice while said print head is at the second position thereof, said assembly including:
• (i) a cup sealingly surrounding the orifice, said cup defining a cavity therein sized to allow the flow of liquid through the cavity, the flow of liquid being accelerated while the liquid flows through the cavity in order to induce a hydrodynamic shearing force in the flow of liquid, whereby the shearing force acts against the particulate matter while the shearing force is induced in the flow of liquid, whereby the particulate matter is cleaned from the orifice while the shearing force acts against the particulate matter and whereby the particulate matter is entrained in the flow of liquid while the particulate matter is cleaned from the orifice;
• (ii) a pump in fluid communication with the cavity for pumping the liquid and entrained particulate matter from the cavity;
• (c) a transport mechanism connected to said print head for moving said print head from the first position to the second position thereof;
• (d) a controller connected to said transport mechanism, said cleaning assembly and said print head for controlling operation thereof;
• and
• (e) a piston arrangement in fluid communication with the gap for generating a pressure wave in the flow of fluid to enhance cleaning of the contaminant from the surface.

A method of assembling a self-cleaning printer, comprising the steps of:

• (a) providing a print head movable from a first position to a second position thereof, the print head having a surface defining an orifice therethrough, the orifice having particulate matter obstructing the orifice;
• (b) disposing a cleaning assembly proximate the surface for directing a flow of liquid along the surface and across the orifice to clean the particulate matter from the orifice while the print head is at the second position thereof, the step of disposing a cleaning assembly including the steps of:
• (i) providing a cup for sealingly surrounding the orifice, the cup defining a cavity therein;
• (ii) disposing an elongate septum in the cup perpendicularly opposite the orifice for defining a gap between the orifice and the septum, the gap sized to allow the flow of liquid through the gap, the septum dividing the cavity into an inlet chamber and an outlet chamber each in communication with the gap, the septum accelerating the flow of liquid to induce a hydrodynamic shearing force in the flow of liquid, whereby the shearing force acts against the particulate matter while the shearing force is induced in the flow of liquid, whereby the particulate matter is cleaned from the orifice while the shearing force acts against the particulate matter and whereby the particulate matter is entrained in the flow of liquid while the particulate matter is cleaned from the orifice;
• (iii) disposing a pump in fluid communication with the outlet chamber for pumping the liquid and entrained particulate matter from the gap and into the outlet chamber;
• (c) connecting a transport mechanism to the print head for moving the print head from the first position to the second position thereof;
• (d) connecting a controller to the transport mechanism, the cleaning assembly and the print head for controlling operation thereof;
• and
• (e) disposing a reciprocating piston in fluid communication with the inlet chamber for generating a plurality of pressure waves in the flow of liquid to enhance cleaning of the particulate matter from the orifice.

A method of assembling a self-cleaning printer, comprising the steps of:

• (a) providing a print head movable from a first position to a second position thereof, the print head having a surface defining an orifice therethrough, the orifice having particulate matter obstructing the orifice;
• (b) disposing a cleaning assembly proximate the surface for directing a flow of liquid along the surface and across the orifice to clean the particulate matter from the orifice while the print head is at the second position thereof, the step of disposing a cleaning assembly including the steps of:
• (i) providing a cup for sealingly surrounding the orifice, the cup defining a cavity therein sized to allow the flow of liquid through the cavity, the flow of liquid being accelerated while the liquid flows through the cavity in order to induce a hydrodynamic shearing force in the flow of liquid, whereby the shearing force acts against the particulate matter while the shearing force is induced in the flow of liquid, whereby the particulate matter is cleaned from the orifice while the shearing force acts against the particulate matter and whereby the particulate matter is entrained in the flow of liquid while the particulate matter is cleaned from the orifice;
• (ii) disposing a pump in fluid communication with the cavity for pumping the liquid and entrained particulate matter from the cavity;
• (c) connecting a transport mechanism to the print head for moving the print head from the first position to the second position thereof;
• (d) connecting a controller to the transport mechanism, the cleaning assembly and the print head for controlling operation thereof;
• and
• (e) disposing a piston arrangement in fluid communication with the gap for generating a pressure wave in the flow of fluid to enhance cleaning of the contaminant from the surface.