What kind of hinge four-bar mechanism is used for the lifting platform of camera car? What role does it play?

In the crank-rocker mechanism, when the crank is the driving part, the continuous rotating motion of the crank can be transformed into the reciprocating swing of the rocker. Such as a pitch angle adjusting mechanism of a radar antenna.

In a hyperbola mechanism, if the lengths of two cranks are not equal, the driving crank rotates at a uniform speed and the driven crank rotates at a variable speed, such as an inertial screen. If the length of two cranks is equal, and the length of connecting rod and frame is equal, it is called parallel double crank mechanism. The characteristic of this mechanism is that the angular velocity of two cranks is always equal, and it is also widely used in machinery, such as locomotive wheel connecting rod mechanism.