Driving device to obtain a progressive bilateral movement for an object guided on rectilinear rails

摘要

An apparatus for causing a load support guided on rectilinear rails to move gradually. The apparatus having a rectilinear slot integral with the support to be driven and a crankpin which engages in the slot and forces the slot to move. The slot (54) is elongated perpendicularly to the direction of movement and is open at both its ends and it has two toothed wheels (42, 43) driven in opposite directions, mounted on either side of a neutral central position of the slot and each bearing an excentric crankpin (50, 52) which engages in the slot an drives it while it runs through a half-circumference round the toothed wheel, the other crankpin engaging in the slot and driving it while it runs alone through the other half-circumference.