- Only the distance which it moved stores energy in a spring and it returns itself.
- Carrying capacity and travel lenght can be selected.
- Because it is a wheel drive,pit and pulling wires are not needed,so that the shop floor will keep safer. Even if the cart hits to operator,the power more than a spring drive doesnot produce,so it is safe.
- It can be drive source for the KARAKURI device.
- Also it can be used in many ways as a drive unit.