Which cam mechanism allows for acceleration during movement?

The cam mechanism that allows for acceleration during movement is the accelerated cam. This type of cam is designed to facilitate a change in velocity as the follower moves along the contour of the cam profile. It enables the follower to gain speed progressively as it travels, which is particularly useful in applications where quick, smooth movements are desired, such as in automated machinery or timing mechanisms.

The key characteristic of accelerated cams is their ability to vary the motion of the follower, providing both acceleration and deceleration. This is achieved through specific designs of the cam profile, which can create varying radii or slopes that dictate how quickly the follower moves in relation to the cam's rotation. This feature is essential for applications that require precise control over the timing and speed of movements.

The other cam mechanisms have more limited functionalities. Uniform motion cams provide a constant speed of movement, resulting in no acceleration or deceleration. Decelerated cams may slow down the motion at certain points, which is the opposite of acceleration. Gravity cams depend primarily on gravitational force to dictate motion, rather than actively controlling the acceleration profile. Hence, the accelerated cam is the best option when acceleration during movement is required.