https://patentbrief.org/company/automatic-electric-co Plain-English explanations of patents assigned to Automatic Electric Co, newest first. en-us Mon, 15 Jun 2026 05:53:30 GMT https://patentbrief.org/patent/us/1537326/insulin-extraction-and-purification A 1925 patent describing a mechanism to automatically signal that a telephone line is occupied, preventing callers from interrupting an active conversation. Tue, 12 May 1925 00:00:00 GMT https://patentbrief.org/patent/us/1537326/insulin-extraction-and-purification