3249037 Retractable ventilating hood May, 1966 Stalker 3215828 Combination space lighting, heating and ventilating fixture November, 1965 Bonvallet et al. 3212425 Forced flow ventilator October, 1965 Hazen et al. 3211080 Draft control unit October, 1965 Rader D199045 N/A September, 1964 Everts ...