Continuous production furnace to heat ring-shaped workpieces

Continuous production roller hearth furnace to heat circular workpieces (10) having

• a furnace housing (1) defining a roller hearth furnace chamber (2) and having an inlet opening and an outlet opening,
• input driven transport means extending from outside of the housing (1) through the inlet opening into the furnace chamber,
• a roller hearth (8) which has a width which is a multiple of the diameter of the circular workpieces to receive a plurality of said workpieces (10) thereon randomly, adjacently positioned;
• outlet transport means extending outside of the furnace chamber from the outlet opening to remove heated workpieces therefrom;
• and means (11) located adjacent the outlet opening to automatically orient the workpieces in single file for removal of the heated workpieces (10) from the furnace chamber in said single file by the outlet driven transport means and for transport to a receiving station (33), comprising limit means (15-19) defining an outlet path (12) having an inlet width matched to the width of the roller hearth (8) and extending in a direction of transport of the workpieces (10) through the furnace and narrowing, funnel-shaped, to a width approximately matched to the width of the workpieces (10), said limit means including
• at least one side wall (14) formed with an outwardly diverging portion (15) at the region thereof directed toward said chamber (14), located laterally with respect to said path and being cyclically movable with respect to said path (12) in a direction essentially parallel to said path (12);
• means (M) coupled to said side wall (14) moving said side wall in said direction essentially parallel to said path;
• and driven conveyor means (21) beneath the path to move the workpieces (10) from the chamber (2) outside thereof in single file along said path.