Patent attributes
A telescopic transmission assembly includes first and second stage rods, and first and second stage casings. The second stage rod is of a hollow structure having inner and outer surfaces and a through hole, the outer surface being provided with external threads, and the inner surface being devoid of threads. The first stage rod is disposed in the through hole to drive the second stage rod to rotate synchronously. The first and second stage rods are telescopically expandable or contractible relative to each other along an axial direction. The second stage casing sleeves over the first stage casing. The first and second stage casings have respectively first and second transmission nuts. The second and first stage rods are in a screw-thread fit with the first and second transmission nuts, respectively. The second stage rod is positioned with the first transmission nut in the axial direction in a rotatable manner.
