Mary Beatrice Kenner: The Inventor Who Changed Women’s Lives | History Hit

Mary Beatrice Kenner: The Inventor Who Changed Women’s Lives

Peta Stamper

09 May 2022
Sanitary belt invented by Kenner (right) / Mary Beatrice Kenner (centre) / Mary Kenner’s patent for the Sanitary Belt
Image Credit: Helen LaRuse, CC BY-SA 4.0 <>, via Wikimedia Commons (right) / Wikimedia Commons (centre) / Google patents (left)

Born into a family of passionate inventors, Mary Beatrice Kenner was dedicated to making life easier for others.

Today, she holds the record for the most patents awarded to an African-American woman by the US government and is best-known for her first patented invention, the sanitary belt. This revolutionary product was designed to improve the comfort of those menstruating and was the precursor to the sanitary pads we recognise today.

Yet despite the ingenuity of her designs, as an African-American woman, Kenner repeatedly faced deeply entrenched attitudes towards race and gender, and never made any money from her creations.

From arranging flowers to breaking records, here’s the story of the extraordinary Mary Beatrice Kenner.

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Inventing was in her blood

From the day of her birth in Charlotte, North Carolina on 17 May 1912, Mary Beatrice Kenner was immersed in a world of invention. Her father, Sidney Nathaniel Davidson, invented several successful products during his lifetime, including a travel-sized clothing press.

Before then, her grandfather Robert Phromeberger had designed a wheeled stretcher for ambulances and a tricolour signal light to guide trains. Kenner’s sister Mildred, 4 years her elder, also went on to patent the popular board game Family Treedition. It was no surprise then that Kenner was inspired to create from a very young age; inventing was in her blood.

What did Mary Beatrice Kenner invent?

Aged 6, Kenner tried to invent a self-oiling hinge for the squeaky door downstairs. Another childhood invention included a sponge-tipped umbrella, thought up after she saw water dripping off a closed umbrella onto the door.

When Kenner was 12, her family moved to Washington DC. She would wander the halls of the United States Patent and Trademark Office to see if an idea had already been invented. On most occasions, they had not.

Kenner continued to be inspired to invent as she grew older. After graduating from Dunbar high school in 1931, Kenner attended the prestigious Howard University for a year and a half. But while she worked hard, she could not complete her studies. College was expensive, and Kenner was treated differently compared to her fellow male students.

She didn’t let this stop her train of ideas. Kenner balanced multiple odd jobs until 1950, when she could afford to buy the premises to set up a florist’s. At last, Kenner had the time to devote to inventing.

How did Mary Kenner create the sanitary belt?

Advertisement for Kotex pads

Image Credit: cellucotton products company, Public domain, via Wikimedia Common

In early 20th-century America, the topic of menstruation was still largely taboo. Most people made menstrual products at home using old cloths or rags, as had been done for centuries beforehand.

Commercial alternatives, including the Kotex pad, were not necessarily an improvement. In fact, the Kotex menstrual pad was described in a 1927 study as “too large, too long, too thick and too stiff”.

Kenner devised a solution. Her idea of a sanitary belt would hold pads in place, preventing them from shifting while people were on the move and causing blood leakage. The belt also featured easily adjustable straps, considering the comfort of individual users unlike the already existing Kotex pads.

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However, the patenting process was costly, and although Kenner had thought up the sanitary belt in the 1920s, she could not get the idea patented until 1956. Even today a basic utility patent can cost around $700.

Her invention soon caught the attention of the Sonn-Nap-Pack Company, who in 1957 approached her about manufacturing and selling the sanitary belt. Yet once they met Kenner and discovered she was black, they pulled out of the deal. Wherever she turned for investment, Kenner faced the same racial discrimination.

Eventually, without a partner to finance her product, Kenner’s patent expired. Other companies could legally make and sell her idea, and she would not get any of the profit.

Seeking solutions

A sanitary belt design

Image Credit: Wikimedia Commons

Kenner remained undeterred by the industry’s racism. Once again, she looked around her to solve the problems faced by people in their daily lives. Her sister and fellow inventor, Mildred, lived with multiple sclerosis which often restricted her movement. So that Mildred could move around independently, Kenner designed a walker with a tray and pocket attached.

Always considering the needs of others, Kenner designed a mounted back scrubber that helped people reach difficult spots when in the bath. She also devised a holder that caught the loose ends of toilet paper for easier use, particularly by blind people or those suffering with arthritis.

Kenner submitted patents for these new ideas, each of which has evolved into items still in use. Yet during her lifetime she never became rich from her inventions. Nor did she receive formal recognition.

On 13 January 2006, Kenner passed away aged 93. Like many other extraordinary women, her contribution to the history of inventions has been largely overlooked.

Nonetheless, Kenner continues to hold the record for the most patents received by an African-American woman for 5 of her inventions, and her enduring legacy is her creative consideration for others.

Peta Stamper