The text and illustrations of US patents published before March 1, 1989 are in the public domain unless the patent text contains a specific notice that portions are copyrighted. See 37 CFR 1.71(d), 37 CFR 1.84(s)
The original patent contains no such notice, so its contents are in the public domain.
Note: This only applies to images published before March 1, 1989. Patents published after that date are most likely copyrighted, unless in the public domain for another reason, such as {{PD-ineligible}}.
This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: cropped, header/footer and irrelevant Fig. 3 removed, dust erased..
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({{Information |Description={{en|1=Patent drawing for Hennessey guitar string bender, figures 1, 2 and 4, patent 4658693, titled Rear operated control device for guitar. }} |Source=US Patent Office, original at http://patft.uspto.gov/ but a better working