Jabez L. Woodbridge’s patent no. 541,409 – the Automatic Gallows Machine was designed to, as Woodbridge claimed “provide an apparatus or machine by means of which the penalty of capital punishment may be inflicted with certainty”. Woodbridge worked as a janitor/warden of the Wethersfield Prison from 1893-1899, and patented his idea in 1895.
There had been confirmed executions with use of this machine, described in the press. According to Atchison Daily, the machine was used (or tested) in 1894 to execute a murderer, John Cronin (i highly reccomend reading the entire article in the link as it contains very detailed description on the execution process). This execution was also mentioned by The Morning Record. Another self-hanging gallows design was described by the Denver Post (Colorado) in 1901.