Spring/clockwork motors

[havoc]

While reading a bit around on the net about wound spring motors (in connection with a 8mm camera) I came accros a few sites with old toy trains driven by clockwork motors. And from there went on to the Mecano motors.

This started me wondering how those are made. Specially the governors. I just wondered if there are somewhere plans of such motors. Or an article on how those were made, the spring in particular. More curiosity than wanting to build one but it never hurts to have something in your drawer just in case.

[DaveD.]

I once had a clockwork thing with a ' blades on rods ' governor. At least thats what I think it was. There was an input shaft that wound a spring up in a barrel, via, presumably, a worm gear. When it was fully wound a click was heard, and a lever dropped down a bit. If you then moved a second lever, the thing unlatched and the ouput shaft rotated slowly with quite surprising torque. The three bladed windmill arrangement, geared up quite a lot from the barrel, whizzed round, the blades flew out down the square shafts, against three light springs wrapped around the shafts, thus presumably increasing the drag.
Nicely made, it MAY have been to wind up the weights on a clock. It had squares on the shafts, and the gears were substantial, not sort of like Meccano. The side frames were nickel plated with a pattern of 'truncated pyramid' dents in it, possibly to work harden it up a bit? Also some small tapped holes which may have been to attach micro switches or similar. Pure supposition on my part. Anyone have a better idea? I don't think it was intended to be wound by hand, it took a 12Volt screwdriver about 20 Secs. to wind it.

I seem to remember it had a US Patent number on it, but nowt else, judging by the number of spare tapped holes it was far from complete.

Just read this thro' - not written by a mechanical engineer is it?
Best I can do

Cheers DaveD.

[chris vine]

Hi Havoc,

The Hornby and meccano motors had a governor with a little weight on a shaft. The whole thing spinning in a cylindrical drum which was fixed. As the motor speeds up the weight is flung against the inside wall of the drum and acts as a brake. The faster the motor tries to go the more the brake resists it.

This of course is a very inefficient mechanism!

Musical toys tend to have a little pair of vanes which rotate fast and govern by air drag and I notice that on some newer ones, there are rubber weights which can flex under centrifugal force and touch a plate above them.

Chris.

[SteveW]

Guys,

My experience was with wind-up gramophone motors. As I recall these were very nicely made and the governor had three brass weights each on a strip of spring steel. Usual method of operation: as the speed increased the weight flew out bowing the steel strips and reducing the length of the governor assembly. At the bottom of the governor was a brass disc that got pulled into a movable felt brake pad. The speed lever simply moved the brake pad allowing the speed to increase a bit before braking started.

I also found out what happened when the little brake assembly was removed. The output shaft went round much faster unit the steel strips broke and the weights just took off. It really went fast after that.

[chris vine]

Steve,

Was it you who invented Pinky and Perky?

C

[lancelot]

Hi Havoc,
Have a trawl through this site and I think that you will find what is required in the way of drawings e/t/c...

ep.espacenet.com/?locale=en_EP

I hope this helps,
All the best for now,
John.