Some Patents

Juan Inurrieta held several patents in his name, with most being utility models primarily related to small items like record sleeves or phonograph needle cases. In 1945, he applied for an introduction patent aimed at preserving needles used in the United States of America.

However, there are several patents associated with the manufacturing process of records attributed to him. On September 6, 1950, he secured utility patent No. 194497, which aimed to enhance the production of phonograph records. This patent introduced the use of thin sheets of compressed fiber at specific temperatures, resulting in a cleaner playback of recorded wavelengths. The material quality utilized in the surface layers, including vinyl, phenol, and other synthetic resins, minimized noise caused by the needle’s friction. These records were recorded with a sapphire needle at an angle of 82-84° and a radius of 0.05-0.06 mm. The number of grooves per inch could range from 80 to 120, with LPs accommodating up to 30 minutes per side and singles up to 5 minutes. An additional advantage was that these 33 1/3 and 45 rpm records provided superior fidelity when the needle approached the center of the record compared to 78 rpm records. At 10,000 cycles per second and 15 cm from the center, the 78 rpm record lost 15 decibels compared to the other two, indicating a greater loss of high frequencies.

In 1952, patent number 204 332 was introduced, outlining a procedure for manufacturing phonograph records using polyvinyl resin mixtures. The patented process involved adjustments to the warming and cooling cycles of the molds to achieve quieter playback, proper resonance, and a broader frequency range than was previously achievable with microgroove records.