I have two Bayliss Wiley Unit hubs: the early low flange version, and a NOS post-war large flange model. I also have a Cyclo "Tank" Unit hub. Please see the photo on:
http://photobucket.com/
and in the following sub-albums accessible from that page: "BW LF UNIT HUB", "BW SF UNIT HUB" and "CYCLO UNIT HUB"
The Bayliss Wiley Unit Hub patent (number GB461951) was published on 26th February, 1937. For full patent details, including drawings, see:
http://v3.espacenet.com/
The BW small flange Unit hub is marked with this patent. The later large flange BW Unit hub in the photos is marked "Patent Applied For", but I have been unable to find any patent having been granted for this model, and I don't know what the specific patent claims were If you compare the photos of the large and small flange BW hubs, you will see a marked difference in the size of the bearing housings, but what the actu8al changes were, I don't know - I haven't stripped any of the hubs (which is probably why they're still working).
The Cyclo Unit hub is marked in French with the Cyclo logo and "BREVETE SGDG" on the barrel, and the Cyclo logo and "SGDG" and "TANK BREVETE" on the adjustable bearing cone. I bought this on eBay from France, hence the French markings, but it has 40 spoke holes (as do the BW hubs) which I understand to be unusual for the French market, 36 holes being much more common. (My hub does not have the eyeletted spoke holes on the freewheel side flange which are specified in the 1939 Cyclo catalogue).
Perhaps they were made in England and exported to France via French Cyclo, and stamped accordingly? The reason I believe that this might be the case is that the 1939 catalogue states that these hubs were "Made under BSA license (sic), Patent No. 498931". For details of this patent, which was published on 17th January 1939, see:
http://v3.espacenet.com/
My hub appears externally similar to the hub in the BSA patent drawings, although it only steps down once from the flange to the barrel, unlike the hub in the patent drawings and the exploded diagram in the 1939 Ccyclo catalogue (and, come to that, the BW hubs). However, if it IS the BSA patent hub, then I think it more likely, particularly in view of the 40-hole spoking, that was British made, and exported. It doesn't seem likely to me that both British and French Cyclo factories would go to the expense of tooling up to make the same pattern of hub.
However, this is all conjecture on my part - it's just as possible that it was made in France, and distributed in the UK by British Cyclo.
It is a "flip flop" (fixed/free) hub, and the BW Unit hub was also available fixed/free - it is listed in the 1939 Brown Bothers catalogue as being available in 4 configurations:
Single freewheel Single freewheel/fixed Three speed Three speed/ fixed
The only options listed in the 1950 Cyclo catalogue relate to 3, 4 or 5 speed, and by this time, it appears that Cyclo had dropped the BSA-licensed model, and were using the Bayliss Wiley Unit hub - if you refer to the 1950 catalogue page, you will see it listed as "B.W. FREEWHEEL HUB UNIT", but referred to in the description as "CYCLO unit". The illustration is of the large flange BW hub.
A couple of general points - the teeth on the sprockets supplied for the BW hubs were flat-topped. The1939 Brown Brothers catalogue states that standard hub sprockets (I assume that this means fixed sprockets) will fit, but will NOT work satisfactorily with derailleur gears. This seems strange, because Cyclo and Trivelox were supplying three speed blocks with pointed teeth, like those of a fixed sprocket, at that time, and in my experience, they work fine. I haven't yet tried a BW Unit hub with fixed sprockets, but I guess maybe Mick or Doug have? I suspect that this was a marketing ploy on the part of BW.
Both the BW and Cyclo unit hubs were listed in the 1952 Brown Brothers catalogue, although the BW illustration is of the small flange hub, and the Cyclo illustration is of the large flange BW! Neither appears in the 1956 edition. The BW hub is also listed in the 1952 Hobday Bros Catalogue (with the large flange hub illustrated) but it doesn't appear in the 1954 edition.
Neil Foddering
Weymouth, England