We claim the ornamental design for a servomechanism, as shown and described.
FIG. 1 is a top view of a servomechanism;
FIG. 2 is a front elevation thereof;
FIG. 3 is a right side elevation view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a front, top, right perspective view thereof; and,
FIG. 6 is a front, bottom, right perspective plan view thereof.
Structural elements depicted by broken lines have been shown for the purpose of illustrating portions of the servomechanism that form no part of the claimed design.
The appearance of the right side of the servomechanism is a mirror image of the left side of Servomechanism.