The use of open fires for cooking, light and warmth has been traced back to the early days of humankind, but for as much as fire brought, in today's world it leaves a few things to be desired.
First, open fires typically burn unevenly, preventing uniform cooking and heating. Second, for cooking, open fires do not utilize efficiently the heat generated because of significant losses to the surroundings. Third, the environmental elements must be contended with whenever the fire was built. For example, rain or snow could extinguish the fire. Moreover, winds could make it difficult to start or sustain a fire. Wind-blown smoke and ash also may be quite problematic. Additionally, open fires may be driven out of control by winds.
Enclosing a fire within a standard stove eliminates these drawbacks, but introduces other difficulties. For example, stoves are typically large and bulky, being designed for use in permanent and semi-permanent locations. Standard stoves are also not airtight, are not versatile, contain no preheating apparatus, and are not efficient. And while portable stoves are available, they often have quite limited cooking surfaces and are not designed for space heating. Furthermore, other portable stoves may require dangerous or expensive fuels which must be transported by the user of the stove.
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USPTO Backgrounds