Lantenhammer (Jawa Speedway engine)
Rumours were there for quite some time.
An Otto Lantenhammer [O.L.] desmo was about to be shown to the world and now it finally is here:
Source: Motorrad nr. 06; 3.3.2006 p. 186-188 [Text Andreas Schulz; Pictures* by Jörg Künstle]
[Classification: Group 8A system]
O.L. already asked for a Patent application [date 2005-07-21 under nr. 10 2005 034 177.2] (Patentamt München).
Not yet published (March 2006).
The patent finally has been granted [14.12.2006] [DE10 2005 034 177 B3] to Mr. Lantenhammer and Mrs. Monika Sedlbauer.
According to O.L.: "Mein System ist viel einfacher - Ich verstehe gar nicht warum da noch niemand darauf gekommen ist."
In English: "My system is much simpler [than Ducati (H.C.)] - I don't quite understand why nobody else invented this before."
Of course O.L.'s system is not new at all. Edgar Sewell's desmo for instance (without idler gear) was patented already 94 years ago: Mar. 7, 1922; US 1,408,781.
See drawing. But there were at least 15 other inventors who were granted a patent for an equal system (Vareille, Chrysler, Whitworth and Bonnot to mention a few).
The trick with the extra (idler) gear and the one direction turning roller camfollower is not new either of course. See my model of this principle as well:
Group 8 A model
The ingenious part to me is his use of the standard Jawa head and "simply" adding two conjugate closing cams to the system.
The rocker-valve connection with chain-links is something I could use in some other desmo-model also, while the easiest solution I have ever seen.
Chapeau for this man!
Too bad it takes money and time to protest against this patent and that other desmo-enhousiasts (tuners/inventors) feel frustrated by it's "protection".
* NB The pictures used on this page are scans from the article in Motorrad. Cropped and resized they are of lesser quality of course than the original pictures!!!
Buy a copy of Motorrad (like I did too) to enjoy the real thing!
Patent pic from Sewell, Edgar Sherman US1408781 (patented Mar. 7 1922)
[Classification = Group 8 A]
picture1 of the perspex-model
picture2 of the perspex-model
Patent Lantenhammer / Sedlbauer