Exhaust oven for cathode ray tubes

An exhaust oven for heat-treating cathode ray tubes of the type having a panel portion and a funnel portion, and for simultaneously evacuating gas contained in each cathode ray tube, said exhaust oven comprising:

• a housing having a ceiling portion, opposite side wall portions and a floor portion, and defining therein a heating zone, a slow cooling zone, and a final cooling zone, and a continuous opening provided along a central portion of the floor portion of said housing;
• a series of evacuating carts movably disposed below the floor portion of said housing and each provided with an evacuation pipe protruding into said housing through said opening of said central portion of said floor portion of said housing, said evacuation pipe supporting a cathode ray tube rigidly secured thereto and having means for evacuating gas contained in a cathode ray tube;
• a baffle structure spaced from said ceiling and side wall portions of said housing in said heating and slow cooling zones, said baffle structure defining with said ceiling and said sidewall portions a hot atmosphere circulating passage between said baffle structure and said housing, said baffle structure including
• a plurality of first openings in opposite lower portions of said baffle structure, said plurality of first openings having means for directing a first portion of the hot circulating atmosphere towards the funnel portion of a cathode ray tube supported on said evacuation pipe;
• and
• a plurality of second openings in opposite intermediate portions of said baffle structure, said plurality of second openings having means directing a second portion of the hot circulating atmosphere towards the panel portion of a cathode ray tube supported on said evacuation pipe, the second portion of the circulating atmosphere being greater than the first portion;
• a perforated plate member disposed at an upper portion inside said baffle structure, and having a large number of openings therein;
• a heating means disposed between said housing and said baffle structure for heating the circulating atmosphere up to a predetermined temperature;
• and
• a recirculation means attached to said housing for forcibly recirculating the hot circulating atmosphere inside said housing.