[PT032ABO], Patent Application, Thomas Alva Edison, February 1st, 1889
https://edisondigital.rutgers.edu/document/PT032ABO
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Title
[PT032ABO], Patent Application, Thomas Alva Edison, February 1st, 1889
Editor's Notes
Abandoned patent application Improvement in Phonographs "The object I have in view is to improve the cutting or turning off tool of my Phonograph so that it will better retain its cutting edge and will produce a smoother and more perfect surface.##I have found that in order to produce the fine and perfect surface necessary for the perfect operation of the Phonograph, a steel turning off tool cannot be depended upon to retain its cutting edge, and I have also found that if a cutting knife is employed having the ordinary cutting edge, i.e., one forming an acute angle, that a rough surface will be produced in turning since the edge of the knife enters under the surface of the material and breaks it up into chips which in breaking away from the surface carry with them a portion of the material below the line of cutting and thus produce a rough surface. For my improved knife I employ a jewel such as sapphire since I have found that sapphire will hold its cutting edge effectively, and I grind the cutting edge to form a right angle or approximately a right angle so that the edge will not enter beneath the surface of the material, but as the edge cuts the material it breaks it above the cutting edge so that he chips do not carry with them a portion of the surface below the line of cutting. The knife is supported so as to present its cutting edge obliquely to the surface as will be well understood. [descriptions of missing drawings follow and then five claims] [Letter dated 890211 from patent office rejecting claims; reply by Dyer and Seely dated 900411; rejected again 900423; abandoned 900531 as "subject matter has been incorporated with certain additional features in a new application executed by me on the 24th day of May 1890."]
Author
Date
1889-02-01
Type
Folder/Volume ID
PT032ABO-F
Microfilm ID
114:593
Document ID
PT032ABO
Publisher
Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University