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(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!

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

Picture 1 of the perspex-model
Picture 2 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).

Picture 1 of the metal-model
Picture 2 of the metal-model
Produced system = Azzariti (Benelli)
Produced system = Daimler-Benz & Co.
Produced system = HPL Moto Guzzi
Patent Azzariti,Vincenzo
Patent Austermann, Josef

GROUP 1B 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.

Picture 1 of the perspex-model
Picture 2 of the perspex-model
Picture page 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.

Picture 1 of the model
Picture 2 of the perspex-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

Picture 1 of the perspex-model
Picture 2 of the perspex-model
Produced system = Bignan (Causan)
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.

Picture 1 of the perspex-model
Picture 2 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.

Picture 1 of the perspex-model vertical cilinder
Picture 2 of the perspex-model horizontal 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.

Picture 1 of the perspex-model (Ducati Pantah)l
Picture 2 of the perspex-model (Ducati parallel-twin)
Picture 3 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 = 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.

Picture 1 of the perspex-model
I don't know of ever Produced systems nor 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.

Picture 1 of the wooden-model
Picture 2 of the wooden-model
Produced system
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.

Picture 1 of the perspex-model
Picture 2 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
Produced system = 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.

Picture 1 of the perspex-model
Picture 2 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.

Picture 1 of the perspex-model
Picture 2 of the perspex-model
Produced system = Lantenhammer
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.

Picture 1 of the perspex-model
Picture 2 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.

Picture 1 of the perspex-model
Picture 2 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.

Picture 1 of the perspex-model
Picture 2 of the perspex-model
Produced system = Ducati triple nocker
Produced system = Norton Manx 500
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.

Produced system = JAP
Prestwich, John Alfred

I still have not made a Group 10 model, but I plan (2007) to copy the JAP system as shown on my site.

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 (2007) to so in the near future.

Cop. 1987 by Henk Cloosterman en Francisco Tijsse Klasen