Josef Dehm

Josef Dehm, 1939

Josef Dehm (born April 8, 1904 in Jöhlingen , Karlsruhe district, † October 26, 1977 in Rinklingen ) was a German inventor and entrepreneur.

Life

Dehm foundry, 1940

Josef Dehm's father, a building contractor, died just as early as his mother. After training as a handformer, he worked in several foundries, including in Karlsruhe and Triberg. After passing the master craftsman's examination, he set up a gray cast iron foundry in Bretten . The rented building was soon too small, so he set up a modern foundry in Rinklingen near Bretten. The number of employees rose to 60. In the foundry and the in-house joinery, after the end of the Second World War, he manufactured tools that were in short supply, including grist mills, handcart trolleys and metal pans.

"The company founded by Josef Dehm [...] provided the Idema building blocks as model and construction kits developed as early as 1946, The Little Builder . For small architects and young engineers with plastic plug -in blocks in their own system", says Ulf Leinweber.

Exhibition stand at the Nuremberg Toy Fair in 1956

The invention and sale of the Idema component tied up Josef Dehm's strengths in such a way that he leased his foundry to the Neff stove company and later sold it to them. As a result of illness, he was unable to run his own business for a long time and between 1958 and 1963 he handed over sales to a Heidelberg company.

The company expanded rapidly in the 1960s. The Idema building blocks were manufactured in modern machinery. "The Idema construction kit [...] became a worldwide success, it was sold as far as Mexico," according to Annette Noschka and Günter Kerr.

The inventions of the Idema module have been patented by the German Patent Office under the numbers 1070420 from June 16, 1952 and 1075871 from March 31, 1955. In the patent from 1952 it says about the first solid stone developed by Dehm: It has "eight protrusions and eight depressions, which are symmetrically arranged in two rows."

At an advanced age, Josef Dehm first leased his company, later he sold it entirely.

Josef Dehm invented several new versions of its device : The normal stones were double stones, giant , hobby stones and mosaic, to wheels, sand blocks and large Styrofoam blocks.

Idema - Showcase in the Deutsches Museum Munich, 2018

Prospectus from the 1960s

Josef Dehm is referred to as a “pioneer in the plastic construction kit sector” in the book Building Blocks in awe .

invention

The Idema building block was based on the masonry brick and represented its imperial format on a 1:10 scale. First made from Bakelite , the stones were later made from polystyrene .

Selection of Idema normal stones

The normal stone had two rows with 4 tenons each on the top, and the same number of holes on the underside to accommodate the tenons. Initially, the stones were held together in a bond with metal pins, later the pegs were slightly larger than the receiving holes on the underside. This made the stones stick together. The Bakelite stones were made of solid material, the stones made of polystyrene were hollow on the inside.

The target group of the Idema building blocks were children, as well as architects, who were able to use them to implement their building projects on a 1:10 scale in advance.

literature

• German Patent Office, Auslegeschrift 1070 420 from December 3, 1959.
• Ulf Leinweber: Construction kits! Technical toys from the Biedermeier period to the turn of the millennium. Staatliche Museen Kassel, Kassel 1999, ISBN 3-928127-64-0 , p. 181 ff .
• Annette Noschka and Günter Knerr: Building blocks are amazed . Two hundred years of construction kit history. Hirmer, Munich 1986, ISBN 3-7774-4180-5 , p. 114 ff .

Individual evidence

1. ↑ Marvel at Building Blocks, p. 115.
2. ↑ Construction sets p. 265.
3. ↑ Marvel at Building Blocks, p. 115.
4. Jump up ↑ Building Blocks, p. 148.
5. ↑ German Patent Office
6. ↑ Building blocks are amazed, p. 114.