> the court said that confusion of large computing machinery with household appliance is unlikely
I still remember the VAX-750 with those large disk drives (they must have held hundreds of megabytes!) and the day some joker placed a box of "Drive" brand laundry detergent on one of them. I'd say that from a distance it was easy to confuse an RP06 disk drive with a washing machine. Maybe not a vacuum cleaner, but certainly a house-hold appliance.