PUSHER-TYPE ATMOSPHERE-CONTROLLED HARDENING FURNACE Russian patent published in 1997 - IPC

FIELD: hardening small long articles whose length exceeds their cross-section by 10 times. SUBSTANCE: furnace has heating chamber with muffle and vertical cooling tube connected with it, loading mechanism with pusher, prechamber with damper, guide made integral with muffle and cassettes. Each cassette is provided with stop and extensible lower partition. Cooling chamber is made in form of hardening tank located under heating chamber. After loading the articles in cassette mounted on guide, lower partition is extended and bottom of muffle is used as bottom of cassette. Article heated in shielding gas is forced into cassette to vertical tube. Distance between pusher and vertical tube is multiple of length of cassette and travel of pusher is equal to width of cassette. From cassette located above hole of vertical tube article is fed to hardening tank vertically at minimum warpage. EFFECT: strain-free hardening of long small articles made from carbon and alloy steels. 3 dwg