Agricultural implement having wheels that caster

A wing boom for an agricultural planting assembly, comprising:

• an elongated boom assembly configured to support a plurality of spaced planting units, the boom assembly having at least one section pivotally coupled to an adjacent inner boom and an outer end;
• a wheel mount connected adjacent to the outer end of the boom assembly;
• a wheel configured to support the outer end of the boom assembly,
• a caster frame configured to rotatably carry the wheel;
• a wheel standard having a first end coupled to the wheel mount on a pivotal axis parallel to the boom and the caster frame pivotably coupled to a second end, the wheel standard movable between a vertical position which is substantially perpendicular to the boom assembly when the agricultural planting assembly is in a transport position and an acute angle relative to the boom assembly when the agricultural planting assembly is in a planting position and the boom assembly is substantially perpendicular to a direction of travel;
• an actuator coupled to a portion of the wheel mount and operably connected to the wheel standard, the actuator configured to move the wheel standard between the vertical position when in the transport position and the acute angle relative to the boom assembly when in the planting position;
• and
• a caster lock connected to the wheel standard and operably connected to the actuator, the caster lock configured to cooperate with a portion of the caster frame to lock the caster frame in a fixed position when the actuator moves the wheel standard into the acute angle relative to the boom assembly when the boom assembly is moved into the planting position so that the wheel is positioned to move only in the direction of travel, the caster lock configured to cooperate with the caster frame to unlock the caster frame when the actuator moves the wheel standard into the vertical position and the boom assembly is moving and moved into the transport position to permit the caster frame to freely pivotably move, so that the wheel positions itself to assist in moving the boom assembly into the transport position and the wheel supports the weight of the boom assembly in the planting position, in the transport position, and in a transition therebetween.