In the Ryan Oneal,Barbara Stisand movie "The Main Event", from 1976-77, she is cleaning their appartment with a Red Kirby Classic 3 that dosent even have a cord! She is also singing while she is 'vacuuming', so maybe thats why.
I remember a Lucy Show episode (the later version, from the late 60s,-early 70s with "Mr Mooney") where Lucy is selling vacuums door to door. The vacuum is a Hoover Portable suitcase type. Lucy goes schlepping all over the neighborhood with the vacuum case wide open, hose,cord and attachments all falling out all over.
There's an early eposide of I Love Lucy where she tries selling vacuums door to door. (i think its a Westinghouse vacuum)When she comes home with the vacuum in tow, she says "Youve just witnessed the death of another salesman!"