Kaufmann Vibrola
Kaufmann Vibrola on Rickenbacker Electro Spanish Kaufmann Vibrola on Rickenbacker 325One of the first mechanical vibrato units was the Vibrola, invented by Doc Kauffman and patented in 1935. His Vibrola was first offered to the general public by the Epiphone guitar company as an option on some archtop guitars from 1935 to 1937. Epiphone sold the Vibrola as an aftermarket option as well (Kohman, Peter, "Epi-Phonic Echoes, Part Five: Masterbilt Oddities", in Vintage Guitar Magazine, pp. 66–70, October 2011). This Vibrola was also used on some Rickenbacker lap steel guitars at around the same time and was introduced on their six string electric guitars beginning about 1937.
Some early Vibrolas on Rickenbacker guitars were not operated by hand, but rather moved with an electrical mechanism developed by Doc Kauffman to simulate the pitch manipulation available with steel guitars. The Vibrola distributed as an option with Rickenbacker Electro Spanish guitars was hand operated like the earliest Epiphone Vibrolas. A later unit was created and used on Rickenbacker's Capri line of guitars in the 1950s, such as John Lennon's 1958 325. It was a side-to-side action vibrato unit (rather than the up-down action of later units) that was notorious for throwing the guitar out of tune, hence John's replacing it with a Bigsby B5. It was later replaced by the Ac'cent Vibrola, which used no coiled springs to change tension, giving it less chance to throw the guitar out of tune.
Read more about this topic: Vibrato Systems For Guitar