William Herzberg patented an indicating sealed shaving cup in 1911, as part of the quest to make sure that your barber didn’t infect you with whatever ailment the previous customer had.

He was not the first, not the last. We have looked at a great many solutions to that problem over the years. But his solution was different enough and simple enough that it warranted a look.

Claimed to be certain new and useful improvements in indicating sealed shaving cups, the invention aimed to provide…

…a barber’s antiseptic utensil or shaving cup provided with an indicating seal which insures the use of the same only by the owner.

The whole thing consisted of a cup in which a brush and soap might be placed, and a seal of a particular construction.

The cover for the cup, marked 3 in the drawing, was made of a material not easily broken. Around the cover and the lip of the cup, there was a cord and a seal made of paper or other suitable material. The end of the sealing strip stuck out and made a tab. The cord was meant to make it easier to rip the seal open.

The words “seal” and “not broken” would be printed on the sealing strip. When the seal was whole, it would read “seal not broken”.

To open, the barber would grab the tab and pull, thus breaking the seal. The seal was meant to tear between the words “not” and “broken”, so the unsealed sealed shaving cup would display the thext “seal broken”.

The customer could easily see that the sealed shaving cup was sealed before use. And thus he could relax, with the knowledge that he was in safe hands.

Unless his barbed decided to go Sweeny Todd on him of course…

You can read the full text of the patent for the indicating sealed shaving cup at Google patents.