The core of the virion consists of helically arranged ribonucleoprotein. The Bendix system places the starter drive pinion on a helically cut drive shaft. The combination of the two components creates a helically shaped field. Line shaft hoists can also use yo-yo type devices instead of helically grooved drums. In the area of the feet there is a helically twisted pedestal. Safety cable is defined as a group of strands right-hand helically twisted without a core. In 1887 Tainter invented the helically wound paper tube as an improved graphophone cylinder. In effect, the electrons travel along the lines of force, although helically, in detail. Later designs addressed the torque ripple issue by sweeping the blades helically (Gorlov type). The wires are placed helically in every layer. Yo-yo, pile-up, or pilewind, hoists use yo-yo type devices instead of helically grooved drums. These sections are arranged helically along the longitudinal axis of the cell. The teeth on the forward gears of most consumer automobiles are helically cut.