Answer:
Conveyor belts
Step-by-step explanation:
The hallmark of assembly lines in Henry Ford's time was a conveyor belt. His theory was how fast the products move in a given time and how quick can the products be manufactured in a industry.
The conveyor belt is a ramp where the products are kept and with the help of workers placed on a given spot who keep assembling the required part on the products as the belt keep moving and the same action is repeated again and again.