The ornamental design for a portion of an eggbreaker device, as shown and described.
FIG. 1 is a perspective front view for a portion of an egg breaker device showing my new design;
FIG. 2 is a perspective view thereof, showing a holder removed from a egg breaker device;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a right view thereof;
FIG. 6 is a left view thereof;
FIG. 7 is a top view thereof; and,
FIG. 8 is a bottom view thereof.
The broken lines in the drawings depict portions of the portion of an egg breaker device which forms no part of the claimed design. The dash-dot-dot lines are included to show an unclaimed boundary.