18 th century motoring

[harry]

[Bill Wright]

Wonderful. It reminds me of my first car.

Bill

[Michael Chare]

Was your first cart that well equipped for back firing?

[Max Demian]

Not very easy to see how it worked, what with the time to get going and the steam obscuring the view. Did the patent on the crank necessitate the odd ratchet mechanism to turn reciprocal to rotary motion? (Probably not as I don't suppose the Frogs would care about English patent law.)

[Paul Herber]

Have you never seen the average French driver's attitude to pedestrians? (I jest, of course)

[Steve Walker]

I think that that vehicle just pre-dated the patenting of the crank. Presumably the idea just hadn't occurred then - odd really when you look at well handles and the like.

SteveW

[Brian Gaff]

Harry you burke, put a description on your links! Brian

[michael adams]

[Andy Bennet]

I think the piston is omnidirectional as far as the power goes, with a spring return at the end of the stroke. If thats the case then the ratchet mechanism is actually quite efficient as you are getting fairly smooth torque at the wheel for the whole wheel rev. I guess the piston on the other side might concievably be at mid power stroke when the other side returns. I think reverse gear selection could be improved though!

[tabbypurr]

AIUI... Piston power output is unidirectional, it powers upwards. One power stroke only moves the roadwheel part of a revolution. There is only one piston. The engine can only continue driving the wheel when the dray coasts far enough to re-engage the ratchet mechanism. Uphill or with low steam pressure that fails to occur. The ratchet mechanism makes gearing from piston to wheel consistent, but of course the piston steam pressure falls greatly during the stroke. I don't know for certain but piston return is most likely by gravity. Top speed IIRC was 2.5mph. And yes, that was a speed record :)

NT

[Marland]

The original is in a museum in Paris and has two cylinders one each side of the driven wheel.

This video on you tube shows how it worked.

ratchet looks like it may have been inspired by clock mechanisms. No engine braking so perhaps best it was slow.

GH

[tabbypurr]

Flip the driving levers puts the engine in reverse, that's the brake system. And at that speed you can always poke a stick through the spokes to stop one of the wheels. Nevertheless it lost control & crashed on its first outing.

MPG must have been horrendous with such low pressure steam.

NT

[Rob Morley]

You'd have to use miles per tree, not per gallon.