The ornamental design for a bed for inversion apparatus, as shown and described herein.
FIG. 1 is a front perspective view of the bed for inversion apparatus;
FIG. 2 is a top view of the bed for inversion apparatus;
FIG. 3 is a bottom view of the bed for inversion apparatus;
FIG. 4 is a right side view of the bed for inversion apparatus;
FIG. 5 is a left side view of the bed for inversion apparatus;
FIG. 6 is a front view of the bed for inversion apparatus; and,
FIG. 7 is a rear view of the bed for inversion apparatus.
The broken lines in the drawings showing the bed for inversion apparatus illustrate the portions of the bed for inversion apparatus that form no part of the claimed design.