The ornamental design for a sewingmachine, as shown and described.
FIG. 1 is a perspective view of the front, top and right side of a sewing machine showing my new design;
FIG. 2 is a perspective view of the front and left side thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom view thereof.
The broken lines shown are included for the purpose of illustrating the unclaimed portions of the sewing machine and form no part of the claimed design.