CLAIM The ornamental design for a lamp chassis, substantially as shown and described.
FIG. 1 is a right side elevation view of the lamp chassis in accordance with the invention;
FIG. 2 is a left side elevation view thereof;
FIG. 3 is front elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The broken lines shown in FIGS. 1, 2, 4 and 6 are included for the purpose of illustrating environmental features such as an exemplary supporting lamp post and lens and form no part of the claimed design.