Here is a 1925 Splitdorf Aero owner's manual.  These were used by McCormick-Deering briefly ,John Deere and others. They had some annoying pot metal issues and were notoriously wimpy. Impulse couplers and housings often self destructed. 

These springs take a beating and are often broken.   The type B impulse with manual reset was used extensively by McCormick-Deering in their earlier years.