In the late 1860s, Margaret Knight was working in a paper bag plant in Massachusetts, USA. The paper bags of the time were conical in shape, with the bag tapering towards the bottom. She felt that a bag with a rectangular shape and a flat bottom could fit more items. So, she designed a  model of a machine for automatically cutting, folding and gluing paper bags with a rectangular shape and a flat bottom. She approached a machine shop to build a working prototype of the machine, so that she could file a patent for the machine.

While the prototype was being build, Charles Annan stole the plan of the machine from the machine shop and filed a patent for the machine. When Margaret came to know of this, she filed a patent suit against Annan in the courts. Funnily enough, the defense by Annan was that this machine was too complicated for a woman to design. However, Margaret was able to prove that she was the true inventor of the patent in front of the court and the court denied the patent to Charles Annan and granted her the patent (can be viewed on Google Patents) (RE9202) in 1871. She along with a partner, went on to found a company (Eastern Paper Bag Company) in Hartford, Connecticut and went on to great success, making paper bags with a rectangular shape and a flat bottom (using the machine as described in the patent) – the same design that is still in widespread use even today. This machine enabled mass production of rectangular paper bags with a flat bottom and the same machine is used even now, with minor modifications.

Margaret Knight was born in 1838 in Maine and showed a keen interest in machines from a young age, with her first invention being a safety device to stop a machine, on detecting something caught in the machine. She went onto be credited with more than 100 inventions and 87 patents. She was also recognized as the “first woman to be awarded a US patent”.

Sources: Wikipedia, Women Inventors,