Lever-screw curvature measuring device‍

‍‍I. I. Arto­bolevsky, N. I. Lev­it­sky. Tcheby­shev's Mech­a­nisms / In: P. L. Tcheby­shev’s Sci­en­tific Her­itage. Iss. 2. The­ory of mech­a­nisms. — Moscow-Leningrad: AS USSR. 1945. P. 71–72. (Russ­ian)

‍‍I. I. Arto­bolevsky, N. I. Lev­it­sky. Mod­els of mech­a­nisms of P. L. Tcheby­shev / In: The com­plete works of P. L. Tcheby­shev. Vol. IV. The­ory of mech­a­nisms. — Moscow-Leningrad: AS USSR. 1948. P. 233–234. (Russ­ian)

‍‍Geo­met­ric 3D model by Math­e­mat­i­cal Etudes.