The Device of Inscrutable Function…

 

 

 

October 2009. Like many over-grown schoolboys, I have always been fascinated by the mechanism, or ‘the works’ of various devices. Old gramophones, wireless sets &c. And in the Olden Days of our youth of course, what we learned – and what we were taught by friends, and if we were lucky, by mentors – could be of great utility. As one example, I was about to tell you how, when the generator of my car failed and the battery finally ran down, I made the last 20 miles home on three 4.5V pocket-lamp batteries in series, the car having been carefully positioned at the top of a slope to start it by rolling. This was of course in daylight. And as another, the time when – unbelievably – the casing of the ignition coil dropped off, taking the coil with it, so naturally the engine cut out instantly. This time, it was very late at night, but by happy chance, the actual coil itself did not fall into the road, but lodged somewhere near the bottom of the engine compartment, so it was retrieved. Sticking out of it were two relatively thick wires, and one thin one. Very well then: the thick ones were the primary, and the thin one was the HT positive. The HT negative was undoubtedly in common with one end of the primary winding. So there were only two combinations to try. We fastened the two thick wires to the two outer terminals of the top of the coil (which remained in place) and stuffed the thin one into the push-fit receptacle, using the thick HT lead from the distributor. The whole mess was secured with plastic tape. The car started immediately and ran just as it had before, and as ignition coils are (normally) among the most infallible components of a car, next morning at the breaker’s yard, I could take my choice from scores of them at 50 pence each. I need hardly say that the above events occurred 30 to 40 years ago. These days, if the car busts, we just call the AA on our mobile ’phone and they come and sort it out for us.

 

Still, I wasn’t going to tell you about those things, and I apologise, gentle reader, for having done so. No: what I really wanted to tell you about was The Device…

 

While browsing on eBay, I saw the wooden box illustrated above. The item description was extremely lucid, and ran something like: ‘A wooden box, containing a clockwork motor, a bulb mounted on the front, with terminals inside for the connection of several wires… &c., &c.’ and concluded: ‘the device has no discernable purpose…’ [My italics] So… The game was afoot! A wooden box containing a clockwork cum electrical mechanism with no discernable purpose was irresistible. It was obtained at no great cost, and is described below…

 

 

Opening the lid of the box revealed seven brass terminals, from which rubber-covered wires ran. The rubber was badly perished, but there was one modern red plastic-covered wire that someone must have put in recently, presumably in an attempt to discern the function of the device. The small (and quite old) bulb-holder is visible on the front panel. This front panel hinges down, so let us see what is revealed…

 

 

The wires from the brass terminals run down and connect with the disc just left of centre. The new plastic wire connects to the bulb, via simple, elegant (and if truth be told, not very essential) ‘contact feet’ that engage with screw heads. Surely wires could have been run directly to the bulb-holder? But it is mean-spirited of us to quibble with the unknown designer and constructor of this remarkable device. What else is there? There is a piece of ceramic insulation, and a small double solenoid – possibly taken from an electric bell – to be seen at mid-right. From this, an arm depends into the clockwork.

 

 

Here is a closer look at it. As will emerge, this solenoid is crucial to the operation of the device. If – when – a voltage is applied to it (and that voltage may be quite low, perhaps 3, 4.5 or 6V at the most) the armature will be attracted to the coils, thus raising a little, the arm which descends into the brass clock mechanism. What happens then? Quite simply, the clockwork motor starts running, and a wiper travels round the segmented disc at the bottom left of the above image. But… there is a limit to what may be described in writing about an inscrutable device like this; so we have taken advantage of the opportunities afforded by YouTube, to make and upload a short video of the device in operation – which may (or may not!) cast more light on it… Just click the link to see it.

 

http://www.youtube.com/watch?v=R6ivzSC_8YI

 

Needless to say, if you know what it is, or might be, please let us know?  Your comments will be put here with full credit.   

 

 

 

 

Page written (& video made) 23rd November 2009.