The inventor of US 1,808,692 A was my Grandfather. I recently discovered this patent online, so I am curious about it.
Assuming this is the patent you are talking about:
https://patents.google.com/patent/US1808692A/en to Earl W. Sudduth
This patent is long expired and is now public domain, so it does not have any enforceable rights, unfortunately. (Also, there is no way to revive or extend the term of this patent).
Although this patent was expired by 1950 and is entirely in the public domain, it still affects the modern patent landscape by serving as prior art for new applications, as these citations from recent patents suggest (see the "Referenced By" section in Google Patents):
Citing Patent Filing date Publication date Applicant Title US 5,474,016 A May 31, 1994 Dec 12, 1995 William J. Haney Overhead barrier warning system for trucks or buses US 6,892,502 B1 Mar 27, 2003 May 17, 2005 David A. Hubbell Space frame support structure employing weld-free, single-cast structural connectors for highway signs US 7,314,020 B1 Dec 9, 2003 Jan 1, 2008 Bill Corker Over-height vehicle barriers EP 1502999 A1 Jul 6, 2004 Feb 2, 2005 Siemens Aktiengesellschaft Support for devices and signs for spanning roads