A conveyer system for vertically and helically conveying a workpiece includes a main bracket, on which interconnected heating furnace and cooling furnace are arranged in parallel. The heating furnace includes a 1.sup.st spiral supporting plate, a conveyer belt arranged on the 1.sup.st spiral supporting plate along the spiral direction and one or multiple gas inlet/inlets to fill protective gas into the heating furnace. The cooling furnace includes a 2.sup.nd spiral supporting plate, the conveyer belt extended from the heating furnace arranged on the 2.sup.nd spiral supporting plate along the spiral direction and one or multiple gas inlet/inlets to fill protective gas into the cooling furnace. A drive mechanism for a conveyer belt is installed on the main bracket. The conveyer belt runs through the heating furnace and cooling furnace and forms one loop via the drive mechanism.

A multi-window platen oven for simultaneously heating a plurality of blanks, for example aluminum blanks, before forming the heated blanks in a production line is provided. The oven includes a plurality of vertically aligned shelves disposed in an existing press assembly so that no additional floor space is required. The shelves are attachable to an upper press bed and one another. The upper press bed lifts the attached shelves to present an open window for receiving an unheated blank and/or removing a heated blank from the oven. The remaining windows remain closed and continue heating while the blanks are transferred to and from the oven. After closing the one open window, another window opens to receive another unheated blank and/or remove another heated blank. Thus, the multi-window platen oven continuously provides blanks which are ready for warm or hot forming.

The invention makes public heating apparatus for vertically and helically conveying workpiece, including the main bracket, on which interconnected heating furnace and cooling furnace are arranged in parallel; The bracket is placed inside the heating furnace, the 1.sup.st spiral supporting plate is spiraling on the bracket, and conveyer belt is arranged on the 1.sup.st spiral supporting plate along spiral direction; one or multiple gas inlet/inlets are set on the heating furnace body to fill protective gas into furnace;

The 2.sup.nd spiral supporting plate is spiraling vertically inside the mentioned cooling furnace; the direction of the mentioned conveyer belt inside the cooling furnace is uniform to that of the 2.sup.nd spiral supporting plate; drive mechanism for conveyer belt is installed on the mentioned main bracket. One or multiple gas inlet/inlets are set on the cooling furnace body to fill protective gas into furnace; the conveyer belt runs through the mentioned heating furnace and cooling furnace and forms one loop via drive mechanism. The protective atmosphere spiral conveying heating furnace and spiral conveying cooling device is energy-saving and space saving with high efficiency.

A multi-window platen oven for simultaneously heating a plurality of blanks, for example aluminum blanks, before forming the heated blanks in a production line is provided. The oven includes a plurality of vertically aligned shelves disposed in an existing press assembly so that no additional floor space is required. The shelves are attachable to an upper press bed and one another. The upper press bed lifts the attached shelves to present an open window for receiving an unheated blank and/or removing a heated blank from the oven. The remaining windows remain closed and continue heating while the blanks are transferred to and from the oven. After closing the one open window, another window opens to receive another unheated blank and/or remove another heated blank. Thus, the multi-window platen oven continuously provides blanks which are ready for warm or hot forming.