Trailer apparatus with configurable wheel assembly and underride guard positioning

A method of adjusting longitudinal positions of components of a trailer, the method comprising:

• providing a trailer apparatus having:
• a primary frame structure having a forward end and a rearward end and a longitudinal direction extending between the forward and rearward ends;
• and
• a supplemental frame structure positioned below the primary frame structure and being movable in the longitudinal direction with respect to the primary frame structure, the supplemental frame structure including:
• a first subframe having an underride guard construct for blocking movement of a vehicle under the rearward end of the primary frame structure;
• and
• a second subframe having a wheel assembly for supporting the trailer apparatus on a ground surface beneath the apparatus;
• and
• adjusting a position of the first subframe with the underride guard construct in the longitudinal direction with respect to a position of the second subframe with the wheel assembly by:
• locking the first and second subframes together against longitudinal movement of the first and second subframes with respect to each other;
• moving the locked-together first and second subframes forwardly as a unit in the longitudinal direction with respect to the primary frame structure;
• unlocking the first and second subframes from each other to permit longitudinal movement of the first and second subframes with respect to each other;
• and
• moving the first and second subframes in the longitudinal direction independently of each other.

A trailer apparatus having a longitudinal axis, the apparatus comprising:

• a primary frame structure having a forward end and a rearward end and a longitudinal direction oriented parallel to the longitudinal axis of the trailer apparatus;
• a supplemental frame structure movable in the longitudinal direction with respect to the primary frame structure, the supplemental frame structure being located underneath the primary frame structure, the primary frame structure resting upon the supplemental frame structure such that the supplemental frame structure supports the primary frame structure, the supplemental frame structure including:
• a first subframe;
• a second subframe located underneath the first subframe, the first subframe resting upon the second subframe such that the second subframe supports the first subframe;
• an underride guard construct for blocking movement of a vehicle under the rearward end of the primary frame structure, the underride guard construct being located on the first subframe such that the underride guard construct moves as a unit with the first subframe;
• a wheel assembly for supporting the trailer apparatus on a ground surface beneath the apparatus, the wheel assembly being located on the second subframe such that the wheel assembly moves as a unit with the second subframe;
• wherein the supplemental frame structure is movable in the longitudinal direction with respect to the primary frame structure, and the first and second subframes of the supplemental frame structure are movable in the longitudinal direction with respect to each other such that the underride guard on the first subframe and the wheel assembly on the second subframe are movable in the longitudinal direction with respect to the primary frame structure.