Abstract: An ink jet printer includes a maintenance station which is simple in construction and small-sized. A cap holder is provided with a suction port communicating with a cap through a communication hole, a discharge port and a vent port. Provided in the cap holder is a cylinder which rotates upon actuation of a piston and which is provided on an outer diameter portion thereof with connection holes such that a pressure chamber is connected to the suction port in a suction stroke, the pressure chamber is connected to the discharge port and the suction port is connected to the vent port in an exhaust stroke. The cap holder contains therein the vent port for a suction pump and an atmospheric opening valve.

Abstract: An ink jet head is disclosed for use with a drop-on demand type printer, and includes an insulating base, a plurality of elongated barriers projecting upwardly from the base so as to form a plurality of slots between the barriers, a plurality of nozzle holes communicating with the slots, and electrodes formed on the side walls of the elongated barriers. Voltage can be applied to the various barriers through the electrodes in order to cause deflection of the barriers and a corresponding reduction in the cross-sectional area of selected slots, so as to force ink contained in the slots to be jetted through the nozzle holes. In order to provide a uniform ink jet intensity from the outermost slots relative to the inner slots, dummy slots can be formed outwardly of the outermost active slots by providing dummy barriers outwardly of the outermost active barriers. In addition, the nozzle holes are formed in a nozzle plate. The nozzle plate can either be mounted against the ends of the slots, or atop the base.

Abstract: A grinding machine comprising a tool mounting head which is movable vertically between a pair of guide columns on which guide surfaces are provided for guiding the head. A plurality of workpieces are mounted on corresponding holding jigs which are mounted by means enabling them to be tilted, and measurement means such as X-ray or optical means are provided to sense the orientation of a workpiece being machined, with signals from the measurement means controlling the tilting of the corresponding holding jig. Jigs are mounted on a rotary table rotatably mounted on a workpiece slide which can be traversed below a grinding tool.

Abstract: A machine tool elevating and guiding apparatus comprising a tool mounting head which is movable vertically between a pair of guide columns. Guide surfaces on the guide columns are positioned closely adjacent to guided surfaces on the tool mounting head and a flow of pressurized fluid is passed at a fixed pressure between the guide and guided surfaces, such as to eliminate tilting of the tool mounting head. At least one guide surface serves as a reference surface, with a thin film of pressurized lubricating oil being formed between this and an adacent guided surface. The tool mounting head is mounted on an elevating feed screw, with means provided whereby the weight of the head is supported independently of that screw, so that a very high degree of precision in vertical positioning of the tool mounting head is attained.