The ornamental design for a strut for an incubator, as shown and described.
FIG. 1 is a front elevational view of the claimed design in association with an strut for an incubator shown in broken lines;
FIG. 2 is a left side elevational view of the claimed design in association with an strut for an incubator shown in broken lines;
FIG. 3 is a right side elevational view of the claimed design in association with an strut for an incubator shown in broken lines;
FIG. 4 is a back elevational view of the claimed design in association with an strut for an incubator shown in broken lines;
FIG. 5 is a top plan view of the claimed design in association with an strut for an incubator shown in broken lines;
FIG. 6 is a bottom plan view of the claimed design in association with an strut for an incubator shown in broken lines; and,
FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 1.
The broken lines immediately adjacent the claimed portions in FIG. 4 represent the bounds of the claim, and all other broken lines are included for illustrating environmental structure. None of the broken lines form a part of the claimed design.