Thanks, that was enough to get me started. In American Genius, page 250, a Burton-Harris is shown with four patents (three dates, but the last date is used twice). They are: June 14 1887 - 364,922 (James C. Harris); May 1 1888 - 382,071 (Burton, half assigned to Harris); May 15 1888 - 383,040 and 383,041 (both Augustus G. Burton).
The 1894 patent is for fluidic dampers (dash pots) to moderate the spring releases. 502,613 (1893) relates to controlling bolts on double doors. Burton had other patents in other fields, as well.
These devices are much more complicated than I would have guessed (but of course it is vital that they work reliably) and some of the patent descriptions are quite long.
Jim
