Consider the remarkable inertia-reel seatbelt design.
Today’s invention is to apply that to the humble toilet roll dispenser.
A pair of arms inside the toilet roll would be flung outwards as the toilet roll was rotated when the end of the paper was pulled. These would cause the cardboard liner to stop and the paper to tear off.
With more certainty than is available by just pulling on the end of a conventional paper toilet roll; the more sharply one pulls the inertia reel paper, the shorter the length of paper dispensed.