Von Duprin: 100 Years Old and Going Strong

Without an original idea, no product would ever see the light of day. We all take exit devices for granted today, but someone, somewhere had to be the inventor of the product. There have always been some disagreements about who really applied for the first exit device patents, but Von Duprin claims to be the first to be successfully manufactured and installed of record.

Carl Prinzler, a salesman for Vonnegut Hardware Company of Indianapolis, was in Chicago on a sales trip in 1903. He planned to attend a show at the Iroquois Theatre, but instead he changed plans and returned to Indianapolis. That afternoon, approximately 600 people perished as a fire swept through the Iroquois Theatre. If not for the change of plans, he also would have been in that building.

One of the reasons for the huge loss of life at the Iroquois Theatre was that the exterior doors opened inward. The crowd pressed against the doors and had nowhere to go. Existing locks available at the time were prone to being ‘knifed’ open if they opened outward, so doors swung inward for security reasons. After the Iroquois fire, City of Chicago laws were changed to require exterior doors in commercial buildings to open outward.

The disaster gave Mr. Prinzler an idea. He enlisted the help of a friend, Henry Dupont, who was an engineer. Together they developed their first working exit device. Letters from the Vonnegut, DuPont and Prinzler names were put together to form ‘Von Duprin’, the name we all recognize today.

Patents for an “Emergency Exit Attachment for Knob Latches” were submitted in October, 1908. A subsequent patent for an “Emergency Exit Lock” was submitted in November, 1908. Their first exit device was installed in 1908 on one door at a high school in Indianapolis, IN. The first exit device proved to be so popular that Indianapolis soon installed the new exit devices in all schools in the city.

Early pictures of Von Duprin hardware show their original latch system and pushbar design. Although some exit hardware modernizing has taken place over the years, the basic pushbar and latch system still remain.

The Von Duprin name and Von Duprin exit hardware have existed for a century. One footnote did happen during World War I. Sales in Europe slowed because people thought perhaps the name “Von Duprin” indicated that the product came from Germany. Von Duprin hardware sold in Europe had the name changed to ‘Prince’ for a short time period.

Von Duprin exit hardware was a division of Vonnegut Hardware Company until June 1,1966. At that time the division was purchased by Schlage Lock Company. Schlage Lock later became part of Ingersoll Rand. Von Duprin remains a popular product in the Ingersoll Rand lineup.