(SUB)CLASSIFICATION OF DESMODROMIC VALVE GEAR (IPC F01L1/30) This classification was designed according to (patentdrawings or otherwise) known systems. Basic assumption here was the commanding of one single valve. Mostly we used as main criterium: the pivot point of the rocker or cam follower finger in connection with the position of the valve and the position of the cam(s). Futhermore we also used the following criteria:
- Number of cams
- Form of cam
- Cams on just one single axis or on more
- Number of cam-followers
- Form of the camfollower
Summer 2007 I added dedicated links to the Groups like: Link to the pics of the perspex models (photo pages) Link to the pages of produced systems Link to the patent pages (only patents of ever produced systems) Of course only as far as available. When there is no link there is no page (information) to link to!
tr>produced system= Lantenhammer
| GROUP 0 | Screw thread- and cam bar desmo | F01L1/30/0 | ||||||
| Screw thread desmo: | Systems consisting of a round external or internal screw thread (nut and bolt) | |||||||
| Toothed rack desmo: | Systems with a toothed rack and a (worm) gear | |||||||
| Cam bar desmo: | Systems with a crankshaft driven translating cam-bar with oscillating camfollower | |||||||
| pictures of the perspex-model | ||||||||
| GROUP 1A | Coulissedesmo | F01L1/30/1A | ||||||
| Form closed systems consisting of a track or groove with a peg or roller follower (single lay out / half joint), or two combined cams with pegs or rollers in both tracks (double lay out / double joint). | This group knows 4 subgroups depending on the position of the followers and cams (inside/outside). | |||||||
| pictures of the metal-model | ||||||||
| produced system = Ariès | ||||||||
| produced system = Azzariti (Benelli) | ||||||||
| produced system = Daimler-Benz & Co. | ||||||||
| produced system = HPL Moto Guzzi | ||||||||
| Patent Azzariti, Vincenzo | ||||||||
| Patent Austermann, Josef | ||||||||
| GROUP 1 B | Face cam desmo | F01L1/30/1B | ||||||
| Form closed systems presenting a cam ring with a fork like camfollower. The cam follower is composed of rollers or sliding shoes and connected with the valve. | ||||||||
| pictures of the perspex-model | ||||||||
| picturepage of another embodiment = metal model | ||||||||
| produced system = Battlogg, Stefan (Porsche) | ||||||||
| Patent Battlogg | ||||||||
| GROUP 2 | Single-Disk Cam desmo | F01L1/30/2 | ||||||
| Systems in which a single-disk cam with positively controlled oscillating followers positivily open and close the valve. | This group knows 3 subgroups: direct systems without rocker; oscillating forklike camfollower and system with rocker. | |||||||
| pictures of the model | ||||||||
| produced system | ||||||||
| GROUP 3 | Camdisk and Camgroove desmo | F01L1/30/3 | ||||||
| Camdisk desmo: | Systems in which a cam follower body encloses a camdisk | |||||||
| Camgroove desmo: | Systems in which a follower runs in a drumlike cam groove. | |||||||
| The followers are rollers or pegs | ||||||||
| pictures of the perspex-model | ||||||||
| produced system = Bignan | ||||||||
| produced system = Capriolo | ||||||||
| produced system = Fiat 401 in Tipo 801 | ||||||||
| produced system = Neander (System Küchen) | ||||||||
| Patent Bignan | ||||||||
| Patent Küchen | ||||||||
| GROUP 4 | Enclosed double-cam desmo | F01L1/30/4 | ||||||
| Systems with the positive and negative (conjugate) cams on one single axis. | ||||||||
| The conjugate cams are encircled by tappets in the form of stirrups connected in some way to the valve. | ||||||||
| pictures of the perspex-model | ||||||||
| produced system = Basse&Selve | ||||||||
| produced system = Roland Brüdersdorf | ||||||||
| produced system = Delage GP | ||||||||
| produced system = Cosworth | ||||||||
| produced system = Karel Horak | ||||||||
| produced system = Rolland Pilain | ||||||||
| produced system = Salmson | ||||||||
| produced system = SEFAC | ||||||||
| Patent Peter Bothwell (Cosworth) | ||||||||
| Patent Horak, Karel | ||||||||
| GROUP 5 | Single-rocker desmo | F01L1/30/5 | ||||||
| Systems with separate cams on the same camshaft for opening and closing the valve. | A rocker is used to close the valve, but the openingcommand is directly on the valve, | often with the interference of a cup follower or follower finger. | ||||||
| pictures of the perspex-model vertical cilinder | ||||||||
| produced system = BMWR1 | ||||||||
| produced system = BRM | ||||||||
| produced system = Ducati 4V experimental | ||||||||
| produced system = Ducati 4V old | ||||||||
| produced system = Ducati 4V new | ||||||||
| produced system = Ducati 4V 1098 | ||||||||
| produced system = Ducati Desmosedici | ||||||||
| produced system = Erla | ||||||||
| produced system = Ferrari F1 | ||||||||
| produced system= Maserati 6 Cil. | ||||||||
| produced system = Mercedes-Benz W-196 + 300 SLR | ||||||||
| produced system = MV Agusta | ||||||||
| produced system = OSCA (Maserati 372 DS) F1 | ||||||||
| produced system = Porsche 753 GP | ||||||||
| produced system = Scarab (Reventlow) | ||||||||
| produced system = Treen 350 cc research engine | ||||||||
| Patent Ducati | ||||||||
| Patent Mercedes-Benz | ||||||||
| Patent OSCA Maserati | ||||||||
| Patent Porsche | ||||||||
| GROUP 6A | Double rocker desmo with separate rockerspindles | F01L1/30/6A | ||||||
| Systems with separate cams on the same camshaft for opening and closing the valve. | The two rockers have their own rocker spindle. | |||||||
| pictures of the perspex-model (Ducati Pantah) | ||||||||
| picture3 of the perspex-model (Ducati parallel-twin) | ||||||||
| produced system = BMW-2V (Franz Pohn) | ||||||||
| produced system = BMW-4V (Franz Pohn) | ||||||||
| produced system = Ducati 1 Cil production | ||||||||
| produced system = Paralleltwin | ||||||||
produced system = Ducati Bevelgear L-twin |
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| produced system = Pantah line | ||||||||
| produced system = Ducati 2V new Generation | ||||||||
| produced system = Ducati 3V | ||||||||
| produced system = Del Biondo | ||||||||
| produced system = Mazzucato | ||||||||
| produced system = Gerrit Rook Special | ||||||||
| produced system = Maserati V8 (6A double cam variant) | ||||||||
| Patent Cenna, Fernando (Fig. 1 only) | ||||||||
| Patent Mengoli, Gianluigi (Ducati) (Fig. 1 only) | ||||||||
| GROUP 6B | Double rocker desmo with shared rockerspindle | F01L1/30/6B | ||||||
| Systems with separate cams on the same camshaft for opening and closing the valve |
using two rockers sharing the same rockerspindle | |||||||
| pictures of the perspex-model | ||||||||
| I don’t know of ever produced systems | no patents from produced systems of course. | |||||||
| GROUP 7A | Three armed desmo with camshaft in the carter | F01L1/30/7A | ||||||
| Systems with separate cams on the same (OHV= lower positioned ?) camshaft for opening and closing. | A camfollower rocker is connected to a connecting bar (push- draw rod) coupled to a rocker that commands the valve motion. | |||||||
| pictures of the wooden-model | ||||||||
| produced system |
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| Patent BMG/Velocette | ||||||||
| GROUP 7B | Three-armed rocker desmo with the rockerspindle positioned between valve and camshaft | F01L1/30/7B | ||||||
| Systems with separate cams on the same OHCamshaft. | Two basic forms exists: | A stiff three armed rocker (two camfollower arms and one arm from pivot point to valve) and an elastically coupled two-armed camfollower body with an extending (“third” arm) from pivot point to valve. | ||||||
| pictures of the perspex-model | ||||||||
| produced system = Arnott | ||||||||
| produced system = Arturoserri | ||||||||
| produced system = Cenna 1966 (Ducati 175 cc) | ||||||||
| produced system = Cenna 2013 (Ducati 175 cc) | ||||||||
| produced system = Foale | ||||||||
| produced system = Howarth | ||||||||
| produced system = Laufoowah | ||||||||
| produced system = Mangoletsi | ||||||||
| produced system = Maserati | ||||||||
| produced system =miller | ||||||||
| producedsystem =Schneider (System Michaux) | ||||||||
| Patent Schneider (Fig. 6) | ||||||||
| GROUP 7C | Enclosed single rocker desmo | F01L1/30/7C | ||||||
| Systems with separate cams on the same OHCamshaft. | The pivotpoint of the rocker is on one side of the camshaft and the valve on the other side. | I.o.w. the camshaft is positioned between the rockerspindle and the valve. | ||||||
| pictures of the perspex-model | ||||||||
| I don’t know of ever produced systems nor patents from produced systems of course. | ||||||||
| GROUP 8A | Double Cam desmo with in between rocker spindle | F01L1/30/8A | ||||||
| Systems with a separate closing camshaft and opening camshaft. | Both cams command a shared arm of the rocker of which the opposite arm is connected to the valve. |
The rocker spindle is positioned between both camshafts and the valve. | ||||||
| pictures of the perspex-model | ||||||||
| produced system= Lombard | ||||||||
| produced system= hartung (NSU) | ||||||||
| produced system= Vagova (Vareille) | ||||||||
| Patent Lantenhammer | ||||||||
| Patent Vareille | ||||||||
| GROUP 8B | Double Cam desmo without in between rocker spindle | F01L1/30/8B | ||||||
| Systems with two separate camshafts. | One with the closing cam and one with the opening cam. | Both camshafts command the shared rocker follower finger. The cams are positioned between rockerspindle and the valve. | ||||||
| pictures of the perspex-model | ||||||||
| produced system = Peeren, Frits & Cees Fick | ||||||||
| GROUP 8C | Double Cam desmo with three-armed rocker | F01L1/30/8C | ||||||
| System(s) with two separate camshafts. | One with the closing cam and one with the opening cam. Both camshafts command the two arms of the shared rocker. | Another arm is connected to the valve. The rockerspindle is positioned between the camshafts and the valve. | ||||||
| pictures of the perspex-model | ||||||||
| I don’t know of ever produced systems nor patents from produced systems of course. | ||||||||
| GROUP 9 | Double Cam desmo with single (two-armed) rocker | F01L1/30/9 | ||||||
| Systems with two separate camshafts. | One with the closing cam and one with the opening cam. The cam for opening the valve is commanding the valve directly (without rocker), possibly with a cam follower finger between cam and valve. | The closing cam commands the closing rocker. | ||||||
| pictures of the perspex-model | ||||||||
| produced system = Ducati triple nocker | ||||||||
| produced system = Norton Manx 500 |
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| Ducati (Taglioni, Fabio) | ||||||||
| Norton (Hele, Doug) | ||||||||
| GROUP 10 | Crankshaft/conrod desmo and excenterdesmo | F01L1/30/10 | ||||||
| Systems commanding the valve motion by a crankshaft/conrod lay out or excenter mechanism. | ||||||||
| pictures of the perspex-model | ||||||||
| produced system = JAP | ||||||||
| Prestwich, John Alfred | ||||||||
| GROUP 11 | Hydraulic desmo | F01L1/30/11 | ||||||
| Systems using oil as the medium between a commanding body or bodies and the valve. | A plunger can be positively moved up and down by means of a desmodromic system | (like a group 1A; group 2 or group 10 system) and with the interference of the medium commanding the valve. | ||||||
| I still have not made a Group 11 model, but I plan (2021) to do so in the near future. |
© 1987 by Henk Cloosterman en Francisco Tijsse Klasen