Thomas Transmission

Here's a pic from an old book that I've had for many years that details various bits of electrical engineering from over 100 years ago, and one example which fascinated me was a transmission for a vehicle that did away with the gearbox. There were various petrol-electric systems around but this one was interesting in the way it worked and was in fact the basis of the present day hybrid transmission. It was patented in 1908 by Frank Thomas, who was Chief Engineer at Leyland before he left to pursue a career as a racing driver. Better known as Parry Thomas, he was sadly killed during a land speed record attempt on Pendine Sands in Wales.
The truck in the pic is loaded with bags of cement, so the all up weight is anyone's guess, probably a fair bit. The engine in it ran at a constant speed and the power was split between driving the truck mechanically and driving the trailers electrically by means of motors on the axles.
There was no gearbox, the speed was regulated by controlling the electric motors. As the engine was running at its most efficient speed it was quite economical, in fact in 1912 a fleet of buses in the Bournemouth area fitted with this transmission were averaging 10.5 mpg which wasn't bad for those old petrol engines on stop-start work.
Anyway, back in 2008 I'd been retired a few years and caught up with all the things I'd been meaning to fix and been where we'd been thinking of going for ages when I came across this book again, so I thought I'd have a go at replicating this transmission. ( To be continued )

Im intrigued, sounds like a diesel electric locomotive except petrol electric

Gunna have to wait and see if Im even close

Paul

Grandad I cannot wait to hear about your progress. What a wonderful project! I have heard of Parry Thomas but did not know his real name was Frank. I have seen pictures of "Babs" the racing car he was killed in, both before and after the accident. I believe that several years ago, the car was dug up from where it was buried on Pendine Sands and restored.
MrsMackPaul There were several makers of Petrol-electric vehicles in Britain and Europe in the early years of motoring. They were very popular for Fire Engine Ladder trucks and other applications where the electric generator could be used to power equipment when the truck was stationery., Tilling-Stevens is probably the best known. I was offered one to restore in the 1970's but I could barely afford to transport it home from interstate let alone restore it. The Daimler-Reynard Road Train of the early 1900's was a petrol-electric.
Tilling-Stevens went on to invent the TS3 motor used in the Commer "knocker"

Ive got a diesel electric in the back yard......and if you think Im making it up,several members of this forum have seen it...........the thing will tow a loaded semi fast enough to get a jump start,and dragged a loaded truck up the slope in the front of Palms yard,when the driver didnt bother with the maxis ........Someone comes into the office ...Theres a bit of traffic jam on Blunder Rd .......Yeah,so what?........Its caused by a truck wrapped up in a chain wire fence......Yeah ,be those idiots at the hire place ......Nope ,its your place ......WTF......cant get in the cab for chainwire .......no worries ,drag it back with the Coles ......did it no trouble.

' Tilling-Stevens went on to invent the TS3 motor used in the Commer "knocker"'
Hi Morris, it was only the TS3s sent to NZ and Oz which had the knock, that's where the nickname came from, the ones in the Uk didn't have it, forget why.
The configuration of the TS3 had been used before, here's one of Sulzer's versions from 1937,


And R.E. Olds' version from 1934


Here's a bit about the Thomas transmission, when I thought about trying to make it the fiddly bit was how to get an epicyclic gearbox, but I found a way of doing it, but don't laugh when you see how.



To be continued.....

Funny how the more things change, the more they stay the same!
For what is now close to a hundred odd year old idea, reading on an overeas forum where they have a 3 cylinder upright version just about ready to go into full production, has the U S military interested. Forget the gross output numbers on the engine, but was surprised as to just what it was punching out. Dave

Here you go Gramps..I tried to put this in you Post but couldn't..

I can see what you mean about it being the Basis for the Toyota Hybrid setup..

With the Coles ,you have to be careful not to over rev the electric motor going downhill.....the previous motor in the Coles had thrown its windings and snapped the armature shaft when it snagged......It had also broken a drive shaft in the worm diff that was 3" diameter .......It would still be operational if I hadnt decided to reposition the motor for more ground clearance .....its a 4x4 ...........I got it off Bobby Addison,and anything he got was very soon pulled to bits and never fixed ,so I guess Im just carrying on the tradition of bodgers.

Hayseed, here's a pic of the Chrysler hybrid transmission patent they applied for in 1948, it has a reference to Thomas in it. It used an alternator and ac motor. It was offered as an option in their cars around then for a short time but as it drove very differently to what people were used to or expected it didn't catch on and was dropped.

All the earlier electric stuff is very heavy due to copper wires and iron cores .....for instance the 40hp motor in the Coles weighs 1 ton ...........now ,the cars can use the new hi power ceramic magnets instead of heavy field coils ...........all the brushless power tools use ceramic magnets ......the motor is effectively inside out.....the armature and commutator is replaced with a magnet rotor ,and the commutator is replaced by solid state circuitry.