Abstract: A first surface of a first metal component of an ink jet print head is bonded to a second surface of a second metal component of the ink jet print head, the first and second surfaces being of materials having the same or similar coefficients of thermal expansion. A layer of filler material is electroplated or otherwise placed on at least one of these surfaces. The filler material has a melting point which is below the melting point of the first and second components, and the total thickness of the filler material on the surfaces together is in the range of from approximately one-sixteenth micron to approximately five microns, with one-eighth micron to two microns being a preferred range. These surfaces are placed together and subjected to heat and pressure to diffusion bond the surfaces without melting the filler material. The diffusion bonding is performed in one approach until no more than approximately one micron of filler material remains between the surfaces.

Abstract: A knock-out in the wall of the housing for electronic equipment is selectively removed to provide a knock-out opening. A wall includes first and second slits positioned along the boundary of the knock-out and separated by a land. The wall includes a break out opening adjacent to each land. Break portions of the wall separate the break out opening from the first and second slits. These break portions are severed to interconnect the first and second slits through the break out opening and permit removal of the knock-out. Plural such slits and break out openings are provided and arranged to provide a knock out of rectangular or other desired geometric shape. The slits and break out openings are sized to provide electromagnetic interference shielding. Also, the break portions are of a length which is approximately no greater than the thickness of the wall and are positioned to facilitate removal of the knock-out without deforming the wall and without leaving burrs in the knock-out opening.

Abstract: An aperture plate for an ink jet head is formed by micro electrical discharge machining one surface of the plate to form a dimple-like recess with a relatively wide flat base. An aperture is then formed through the plate in the region of the dimple, as by micro electrical discharge machining. In one method of the invention, recesses are formed in two plates which are then mounted to the body of an ink jet head. A third plate with a formed third aperture is then mounted to the body such that the first, second and third plates overly one another and the third aperture is aligned with the recesses. Apertures of a smaller cross-section than the third aperture are then formed in the first two plates by drilling through the third aperture. The aperture through the first plate is then enlarged.

Abstract: An ink cartridge 10 includes an ink level sensor 38 having a probe supporting structure, such as platform 174, which projects into a collapsible ink container 16 from an ink container support 18. First and second electrical probes 40, 41 are embedded within the structure, with tip portions 188, 190 of the probes 40, 41 being exposed to provide an electrically conductive path through the ink between the probes. Flat closure surface 176, 178 are provided between the exposed portions of the probes against which the container 16 collapses. When the ink container 16 collapses against these surfaces 176, 178, the resistance between the probes increases, is insensitive to ink conductivity, and indicates that volume of ink within the cartridge is low. The platform 174 is supported by tapered necks 180, 182 projecting into the ink container from the ink container support 18.