Why the raised / stepped up top?

[R D]

I was wondering if anyone knows why these stoves were made with the top being stepped up at the rear at the flue? I saw in the advertising literature that it offered two cooking temperatures. And I imagine it helps make room for a baffle. It seems like some contemporary competitor stoves adopted this design, and some had flat tops. Wondering if the flat tops ran just as well.

Thanks in advance for your thoughts

 

[coaly]

The reason, and the reason for the patent is to raise the outlet above the top of door opening to prevent smoke roll-in when opening door.

The patent infringement case against All-Nighter was lost due to the judge ruling that you cannot patent something that works naturally, such as heated gases rising. This allowed copying the step top design and has been used for many infringement cases ever since.

The rear top gets hotter than the front, but with a proper sized baffle, this reverses the hotter of the tops to the front.