This ad comes from Moving Picture World 4 January 1913. The inventor, Daniel W. Barton, would patent several other attachments for the piano besides the one mentioned in the ad. The patents for the bell attachment and two other devices are given below. Clicking on the images should take you to a copy of the patent.
Patent number: 1050513
Filing date: Oct 25, 1911
Issue date: Jan 14, 1913
Patent number: 1174956
Filing date: Apr 21, 1913
Issue date: Mar 14, 1916
Patent number: 1174957
Filing date: May 7, 1913
Issue date: Mar 14, 1916
