US Patent 11691481 Maintenance window structure for large vehicle

A maintenance window structure, for a large vehicle configured in a chassis frame that accommodates driving components of a large vehicle, includes: at least one main opening configured to communicate with a receiving space of the chassis frame and formed on a window frame; the window frame mounted on the chassis frame; a pillar frame detachably provided on the window frame and configured to partition the at least one main opening into a plurality of inspection openings, and an inspection cover that is configured to engage with the window frame and the pillar frame and to cover the plurality of inspection openings.