<html><head></head><body lang="EN-US" link="blue" vlink="purple" data-blackberry-caret-color="#00a8df" style="background-color: rgb(255, 255, 255); line-height: initial;"><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);">Dear Julien</div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;">It used to be well known in Boy Scout circles - fan stoves with the ability to burn just about anything. </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;">There is a charcoal stove in South Africa that has a patent on its lower surfaces involving cooling them with incoming air that probably overlaps one of the ZZ Stove patents. It was filed a few months before I filed my Vesto patent and there has been 'correspondence' about all three. They all use waste heat to advantage though not in the same manner or for identical claims. </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;">My point is, there isn't much new under the sun. I don't think ZZ had a product that generated electricity. </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;">I am pretty sure with the right fuel dimensions the ZZ stoves would qualify as 'improved' in any country. It just happens that they are long in the market and we'll established and not needing support from anyone. As you note, they have been there for ages. </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;"><br></span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;">Regards </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;">Crispin shovelling snow :( </span></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><span style="font-family: Calibri, 'Slate Pro', sans-serif; font-size: initial; line-height: initial; text-align: initial;"><br name="BB10" caretmarkerset="INVALID" class="markedForCaretMarkerRemoval"></span></div> <br><div id="_originalContent" style=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="Generator" content="Microsoft Word 14 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--><div class="WordSection1"><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Tom Reed can provide some history. I have four of them that we evaluated for Tom in about 1990.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Tom Miles <o:p></o:p></span></p><p class="MsoNormal"><a name="_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></a></p><p class="MsoNormal"><o:p> </o:p></p><div><div><p class="MsoNormal">Hello Stoves;<o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">Jeremy Warfluft was certainly doing some interesting research in 1984. One of the stoves mentioned in his document was the Z-stove, developed by the Hottenroths. They hold a number of very interesting patents:<o:p></o:p></p></div><div><p class="MsoNormal"><br clear="all"><o:p></o:p></p></div><div><p class="MsoNormal">Hottenroth, FW Sr.; Jacoby, HD. 1966. Forced Draft Solid Carbon Fuel Burning Cooker US Patent 3,279,452<br>Hottenroth, FW Sr.; Hottenroth, FW Jr.. 1975. Portable forced draft solid fuel burning cooker. US Patent 3,868,943<br>Hottenroth, FW Sr.; Hottenroth, FW Jr.. 1976. Portable forced draft cooker. US Patent 3,982,522 A<br>Hottenroth, FW Sr.; Hottenroth, FW Jr.. 1984. Compact stove for emergency and other uses. US Patent 4,471,751<br>Hottenroth, FW Sr.; Hottenroth, FW Jr.. 1988. Biomass Stove. US Patent 4,730,597 <br>Hottenroth, FW Sr.; Hottenroth, FW Jr.. 1991. Portable Stove. US Patent 5,024,208<o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">Some of their stoves look like modern TLUDs, although I suspect that they didn't have top-lit operation in mind, but where thinking of burning chunky fuel with large pore-spaces, which would produce a fire at many levels down to the grate.<o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">The Z-stove in Warfluft's document was probably an earlier version of the Hottenroths'1988 patent, <a href="http://www.google.com/patents/US4730597">http://www.google.com/patents/US4730597</a><o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">Their 1966 patent looks strikingly like a flattened version of a modern forced draft TLUD: <a href="http://www.google.com/patents/US3279452">http://www.google.com/patents/US3279452</a><o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">Has anyone ever heard of, or see a "Z-stove"?<o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">Cheers,<o:p></o:p></p></div><div><p class="MsoNormal">Julien.<o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal"><br>-- <o:p></o:p></p></div><div><div><p class="MsoNormal">Julien Winter<br>Cobourg, ON, CANADA<o:p></o:p></p></div></div></div></div><br><!--end of _originalContent --></div></body></html>