Bevel gear 1 is keyed to shaft a, rotates about fixed axis A-A and meshes with two bevel planet gears 3 of equal size which are connected by turning pairs B to carrier 4. Shaft b of carrier 4 rotates about axis A-A. Planet gears 3 mesh with bevel gear 2 which rotates freely about shaft b and is rigidly attached to gear 5. Gears 1 and 2 have the same number of teeth. The two addends are proportional to the angles of rotation ϕ₁ and ϕ₂ of gear 1 and gear 2. Angle ϕ₄ of rotation of carrier 4 (and shaft b) is proportional to the half-sum of addends ϕ₁ and ϕ₂, which are entered by turning shaft a and gear 5. Thus ϕ₄=(ϕ₁+ϕ₂)/2 . The required sum of the two addends is read off on a special registering device (not shown).
$2946$CxG,MO$