Any ideas what this pulley is for?

I bought this mystery object at a swap meet recently and was wondering if anyone can help me identify it. It has a double pulley with about 1.8m of chain on each one. One of the chains has a large hollow brass weight that is half filled with lead to weight almost 1.4kg. The other chain has a tag with the word "OFF" on it. One of the knobs on the end of the axle adjusts a spring loaded taper to allow adjustment of the friction on the pulley. The only text on it is "SHAW'S PATENT" stamped on both sides of the pulley. The forks that hold the axle are hollow and are connected at the top to a tapered plug valve that has had the handle cut off. I have dismantled the valve plug to see that it was designed to open and close the flow between one of the forks and the port on top of the valve. There is no obvious flow path for a fluid when it reaches the bottom of the fork. My guess is that it is a Victorian era gas valve for supplying a lamp counterbalanced to allow it to be raised and lowered. I believe that it has been modified over it's life so it is not very clear how it worked. There may be some parts missing.

Does anyone know what this is? It might end up as a counterbalance for my dremel tool but I'd like to know what it was originally first if I can.

Wecome, Neil

My guess would be that it's part of a Rise and Fall light ... probably from a Dining Room, or perhaps over a Billiard Table.

MichaelG.

Neil.

Thanks to the wonderful resource that is espacenet

... I found this.

MichaelG.

Edited By Michael Gilligan on 24/10/2014 16:44:37

A very posh and quite large rise and fall light system , lacking a light fitting and shade.

I remember smaller ones with porcelain pear shaped bit in a dental mechanics work shop in about 1950, but I think not new then.

The idea was you could push the light up out of the way or pull it down for an intense local light.

The pear shaped bit is a container that you filled as required with lead shot to balance the light fitting shade and bulb.

John

Perfect answers - thank you. I knew that someone here would have the goods!

My first thought was a raise and lower pulley for a gas lamp but there was no obvious path for gas flow. Clearly the original gas hose is long gone and someone decided to modify it for some other purpose by fitting a chain instead. Having one chain with the word "OFF" was also a bit of a curve ball. The patent document explains precisely what it was originally.

I don't know if they were ever used for gas lighting, they were used for electric lights. I think a rubber tube being flexed like it would be in a system like that would not last too long. 60 years ago I could have asked my grandfather, he was a plumber and gas fitter in Scotland, he would have known.

Ian S C

We've had them in the last 2 houses with electric lighting and they always use a nice braided cord for a smooth action on the rise and fall

Presumably this one uses clunky chain because of the fire-cutting risk with gas lighting

Reeving the blocks properly so they work correctly is a bit of an artform

.

Ian,

It's worth having a good look at the patent that I linked

... also at some of his earlier ideas.

MichaelG.

Don't think they got round to using that system for gas lighting out this way, but we were early with electric light. By the 1930's the ceiling stud height had come down (10', so there just wasn't the room for anything other than fixed lights on a short pendant. Now it's an 8' stud.

Must have a look around next weekend when I'm at Homebush, the old homestead was at first lit by Acetylene (we'v got part of the old gas generator, and some bits)

Ian S C

Edited By Ian S C on 26/10/2014 09:27:07