The Spinning Jenny was an improved version of the spinning wheel. Credited to Englishman James Hargreaves in 1762, folklore says that it was named after his daughter, Jenny. While a spinning wheel could spin just one thread at a time, the original Spinning Jenny could spin eight threads at once, and eventually evolved until 80 threads could be spun at the same time. The working parts of a Spinning Jenny are vital to its success.
A Spinning Jenny has a vertical wheel, just like common spinning wheels. A handle is attached to the wheel so that users can rotate the wheel, moving it around manually. Some models of the Spinning Jenny had a foot pedal that could be pumped to spin the wheel.
To bring the spinning wheel to a halt, there is a brake on the wheel, which effectively places the wheel in a parked position.
The frame of Spinning Jenny is referred to as the carriage. At one end of the carriage are two planks of wood called the crossbar, which hold the lengths of thread or yarn taut as they are spun. Inside the frame is a roller, called a drum. The drum resembles a long, wide rolling pin. When the spinning wheel is turned, the roller rotates with the use of a pulley, moving the arm, bobbins and spindles.
Spindles are located at the opposite end of the crossbar and hold unspun thread (also called twisted thread) waiting to be spun. Spindles turn rapidly as the wheel is turned, spinning twisted thread into thread or yarn.
The arm, also called the flier, is fixed upon the spindles and pulls twisted thread from the spindles to be wound upon a smaller spindle. A faller wire is released with a hand lever when the spinning is complete. Cords tighten from the weight of a counter balance, ending the spinning project, resulting in a spindle of spun thread or yarn.