Manufacture of tubular elements for ink jet printers.

摘要

A method for the manufacture of tubular elements (15) of substantially transparent material entails the progressive reduction of the diameter of the element while its internal diameter is measured continuously and the stopping of this reduction when the diameter reaches a predetermined measurement. In order to form a glass tube for an ink-jet printer the reduction in diameter is effected by heating an axially limited section (15) so as to form an hour-glass shaped profile. The tube is then cut along a plane so as to make the hour-glass profile coincide with a reference profile. The severed end of the tube is then lapped and covered with a non-wettable material. Finally the tube is glued under vacuum within a cylindrical piezo-electric transducer.
<??>The apparatus for manufacturing the tubes includes a vertical mandrel (12) which receives the tubes one at a time from a feeder (17, 18) and rotates them relative to a pair of gas nozzles (13) for heating the said section (15)
<??>The profile of the tube is scanned by a television camera (24) which generates two signals indicative of the internal diameter. These are compared electronically (23) with a stored indication of the desired diameter and the two nozzles (13) are rotated into an inactive position when this diameter is reached. In order to cut the tube an optical device is provided which is connected to a cutting wheel to permit comparison of the hour-glass profile of the element with a reference profile. The tubular element (11) is bonded within the piezo-electric tranducer, by locating the latter partially in a chamber, after fitting it over the tubular element, while a pump draws an epoxy resin through the chamber and into the space between the transducer and the tubular element.