Along the Farmington River at 37 Mill Street in Unionville were once the factory of the Upson Nut Company. The company, which produced nuts and bolts, was founded by Andrew S. Upson (1835-1911), as described in his obituary in The Iron Trade Review, Vol. XLVIII, No. 14 (April 6, 1911) (from http://historicbuildingsct.com/?p=23730) Upson Nut was founded in 1872.
The Standard Rule Co was the youngest firm in the Upson Nut group, also founded in 1872. Standard Rule’s factory was located in Unionville, Connecticut.
Within three years the Standard Rule co had become the fourth largest ruler manufacturer in the United States. It is not known if they began operation from scratch or by purchasing another rule manufacturer.
Standard Rule and Upson Nut merged in 1888. In 1889 the Upson Nut plane was patented by George Karrmann and manufacturing began. Karrmann said this was an improvement in bench-planes, being a device for the lateral adjustment of the cutting-bit; and the chief object of the invention is to provide a friction-slide and operating device for moving the cutting-bit by frictional contact only.
Granted:Sep. 10, 1889
George Karrmann – Unionville, CT
US Patent: 410,710