Sweeper Vac
That's definitely an Apex tank cleaner - post world war II. Apex private labeled for anyone who wanted a cleaner with their name, but didn't want to actually make it.
There once was a company called Pnuevac, who made a cleaner with a motor driven brush called the "Sweeper-Vac". Hoover sued them. The design was bought by Western Electric, and renamed the "Western-Electric Sweeper-Vac". Eventually, Western Electric reorganized, and the machine was made by "the Sweeper-Vac Company". It's claim to fame was there were no wheels on the nozzle to keep it from sitting flat on the carpet, and the brush was driven by a belt that rotated in a tray on the bottom of the motor housing. The belt (and pulley) could be moved off the armature shaft when you wanted the brush not to rotate (bare floors, etc.) or could be make to rotate by placing "that lever" (their words) to the left, which engaged it with the drive shaft.
By the mid 1920's, better models were made and sold. Eventually, the "Sweeper-Vac" company became simply a name that could be purchased and put on another manufacturer's cleaners. The same thing that happened with the General Electric name being used on Eureka cleaners sold at Wal-Mart several years ago.
