Today in Technology History
(To receive "Today in Technology History" by e-mail, click here. To read past issues click here.)
November 8
The electrical plug was first patented 97 years ago.
When electricity first started to move into the home in the late 1800s, it was only used for lighting. Since the only electrical appliances were incandescent lights, houses were only wired with light sockets, such as the screw socket designed by Edison -- which we basically still use today.
This image is from Hubbell's historic patent. We've colored the plug blue so it's easy to distinguish. Click the picture to see more from the patent. It soon became clear that electricity could power other useful appliances. Unfortunately, it wasn't easy: anything that didn't screw into a light socket had to be directly wired into the home's electrical circuits.
Then along came Harvey Hubbell II, who had founded a machinery company in Bridgeport, Connecticut back in 1888. (In 1896, Hubbell had patented the "pull socket," which we still use today: a socket with a string or thin chain for switching a light on and off.)
In the early 1900s, Hubbell invented an adaptor that could be mounted onto a light bulb socket. The adaptor had two holes which matched the prongs on a device Hubbell called a "separable attachment-plug." He was granted a patent (#774,250) for this invention on November 8, 1904.
Now, Hubbell wrote, "electrical power in buildings may be utilized by persons having no electrical knowledge or skill in the use of tools in attaching lights, fans, motors, heating apparatus, surgical instruments, or any of the various appliances requiring the use of an electric current to fixtures in the circuit."
Eventually, the outlets were attached directly to the circuitry in a home, instead of just mounting onto light sockets that were already there. Two-prong plugs became the standard for most electrical appliances. While there have been many changes in the design of electrical plugs, most notably the introduction of a third prong for safety reasons, the basic principle remains the same.
Related links:
Hubbell's company still exists. Click here to read about its history.
Click here to read a little more about Hubbell.
| Biotechnology | Convergence | Creativity | Culture | E-conomics | Education |
| Equity | Gov't & Politics | Innovation | National Security | Personal Security |
For errors, broken links, questions or comments,
contact webmaster@tecsoc.org.
