The ornamental design for wheelchair lift assist mechanism, as shown and described.
FIG. 1 is a perspective view of one side and the front of the wheelchair lift assist mechanism according to one embodiment of my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken line showing of the front pegs in FIG. 1 is included for the purpose of illustrating environment and forms no part of the claimed design.
The handles in FIGS. 1, 4-7 are shown broken in the middle to indicate indeterminate length, with the understanding that the “indeterminate” length portion of the article not shown forms no part of the claim design. Patentability is based only on those portions of the article that are shown in solid lines.