This is the vacuum I’ve had for some years. Recently I was using it and the head fell off, and not where it has a quick disconnect.

This connection point provides one of the heads axis of rotations. There is a slot where a retention clip rides in a groove while rotating and holding the connection together axially. There is also a seal to maintain the vacuum while it rotates.

The clip that rides in that slot to keep the head on has gotten brittle over the years and broken into multiple pieces, eventually releasing the vacuum head.
Down in the tube that goes from the head to the handle, there is a slot that the clip fits into. The clip looks like it was designed to be a kind of spring that would allow you to press the head into position, and then the clip would pop into the groove and retain it. I took some measurements of the slot as best I could and made a quick model in fusion 360.

After testing it out I had to make the locking tabs a bit longer. Taking measurements was awkward and they were not perfect.

The new part fit in the slot nicely and with a bit of effort the head pushed back on and clipped in place. Back to vacuuming….

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