Apex. Vactric & Bylock
As far as I know there is no direct connection between the three companies beyond the US company providing the design (at least) for the two UK companies. Vactric was a relitavly small company, with basically two cannister lines and one upright. The Silent Q appears to have made its first appearence in the mid 1920s. It seems to have been replaced (although the models may have run side by side for a while) with the W100 - which had the leather strap, toggle switch and the cable connector mounted vertically behind the switch shortly before WW2. I believe it was the first sight of the distinctive (and in my view horrible) Vactric runners. After WW2 it was remaned the W101, in an attractive sea green colour, and fixed handle - in my view the most attractive of all of them. It later became the W202 and W404 (and National Utilities) with the brown "bakelite" ends and open chrome handle - it was this model which Doug refers to being on sale in Canada. They also ran a cheaper, lower powered and physically smaller cannister known as the "Popular". In the mid 1930s the introduced an upright similar looking, in many ways, to the Hoover Junior 370. This ran until the late 1950s shortly before the company folded.
I presume they imported the Apex model in order to compete against the Hoover 800/825, or possibly they assembled it from parts. Likewise the washing machines, in order to get a hold (which they never did) on the embryonic washing machine market, as were Goblin. They were still trying to sell washing machine in the 1950s, although by that time the market was expanding rapidly and highly competitative. It would be interesting to know if their single tub wringer machine was also by Apex.
They also did some three head floor polishers and shortly before their demise in early 1960 they produced a new upright, somewhat resembling the Hoover 638 I have only seen those is advertsiments.
In its time the 202/404 was right at the top of the price market, in 1960 it was almost the same price as all new Lux 65 and not far behind the Hoover 652 so it is surprising that there are SO many of these machines still about - they crop up quite regularly on UK ebay, especially when up against more modern machines like the Connie and Lux models. They also seem to have had a fairly extensive operation in Australia as well with an assembly plant and, apparently, a pretty extensive sales force.
Al