Air return bulkhead with removable panel for access to the lower region of a trailer refrigeration unit

In combination, an air return bulkhead to be used within a refrigeration container for conducting return air from the cargo area of the refrigeration container to an air inlet portion of a refrigeration unit disposed within the refrige-ration container, comprising:

• a refrigeration unit having an air inlet portion;
• a first lower panel member adapted to be fixedly mounted to a wall member of the refrigeration container such that a first surface portion of said first lower panel member is spaced from the wall member of the refrigeration container in order to partially define a return air conduit, between said first surface portion of said first lower panel and the wall member of the refrigeration container, for conducting return air toward said air inlet portion of said refrigeration unit disposed within the refrigeration container;
• a second upper panel member removably disposed atop said first lower panel member such that a second surface portion of said second upper panel member is disposed in a substantially coplanar manner with respect to said first surface portion of said first lower panel member so as to effectively complete the definition of said return air conduit leading up to said air inlet portion of said refrigeration unit disposed within the refrigeration container;
• said first lower panel member comprising a plurality of transversely oriented first rib members extending across said first lower panel member wherein said plurality of first rib members are vertically spaced with respect to each other so as to define a plurality of first spaces therebetween;
• and
• said second upper panel member comprising a plurality of transversely oriented second rib members extending across said second upper panel member wherein said plurality of second rib members are vertically spaced from each other so as to define a plurality of second spaces therebetween such that said plurality of first rib members and said plurality of first spaces of said first lower panel member interengage said plurality of second rib members and said plurality of second spaces of said second upper panel member in an interdigitated manner so as to achieve said removable mounting of said second upper panel member upon said first lower panel member,
• whereby when personnel require access to said refrigeration unit, only said second upper panel member needs to be removed in lieu of requiring the removal of the entire air return bulkhead comprising said first lower and second upper panel members.