Method of manufacturing an ink jet head

A method of manufacturing an ink jet head of the type having a body which defines a horn compartment with first and second ends, a first plate mounted to the body when the ink jet head is assembled so as to close the first end of the horn compartment, the first plate having first and second opposed surfaces and a first aperture communicating between such surfaces, the first surface of the first plate bounding the horn compartment, a second plate mounted to the body when the ink jet head is assembled and having first and second opposed surfaces, the first surface of the second plate and second surface of the first plate defining an ink compartment therebetween which is in communication with the horn compartment through the first aperture, the second plate having a second ink drop-forming orifice passageway or second aperture communicating between the first and second surfaces of the second plate, the first and second apertures being coaxially aligned, comprising:

• forming a first recess in the first surface of the first plate;
• forming a recess in the first surface of the second plate;
• mounting the first and second plates to the body;
• forming the first and second apertures through the first and second plates and at the location of the recesses after the first and second plates are mounted to the body.

A method of manufacturing an ink jet head of the type having a body which defines a horn compartment with first and second ends, a first plate mounted to the body when the ink jet head is assembled so as to close the first end of the horn compartment, the first plate having first and second opposed surfaces and a first aperture communicating between such surfaces, the first surface of the first plate bounding the horn compartment, a second plate mounted to the body when the ink jet head is assembled and having first and second opposed surfaces, the first surface of the second plate and second surface of the first plate defining an ink compartment therebetween which is in communication with the horn compartment through the first aperture, the second plate having a second ink drop-forming orifice passageway or second aperture communicating between the first and second surfaces of the second plate, the first and second apertures being coaxially aligned, a third plate mounted to the body when the ink jet head is assembled, the third plate having first and second opposed surfaces, the first surface of the third plate and the second surface of the second plate defining an air chamber therebetween which is in communication with the ink compartment through the second aperture, the third plate having a main external orifice or third aperture communicating between the first and second surfaces of the third plate, the first, second and third apertures being coaxially aligned, comprising:

• micro electrical discharge machining a first recess in the first surface of the first plate prior to mounting the first plate to the body;
• micro electrical discharge machining a second recess in the first surface of the second plate prior to mounting the first plate to the body;
• micro electrical discharge drilling the third aperture through the third plate prior to mounting the third plate to the body, the third aperture being of a larger cross-sectional dimension than the first and second apertures;
• mounting the first, second and third plates to the body;
• thereafter passing a micro electrical discharge drill through the third aperture and micro electrical discharge drilling through the second and first plates in sequence to form holes through the respective second and first plates, the hole through the second plate comprising the second aperture;
• and
• passing a micro electrical discharge drill through the horn chamber to the first plate and micro electrical discharge drilling the hole through the first plate to enlarge this hole and form the first aperture.