Linkage mechanism for an extendable asphalt paver screed

An asphalt paver screed comprising:

• a main screed;
• at least one extender screed having an upper frame and a lower frame, the upper frame connected to and being slidably movable relative to the main screed to permit the at least one extender screed to extend laterally outward relative to the main screed along an axis generally parallel to a first horizontal axis, and the at least one extender screed having a linkage mechanism connecting the upper frame to the lower frame to maintain the upper frame in a vertically spaced relationship relative to the lower frame, the linkage mechanism comprising:
• a plurality of elongate links with each link extending between and connected to the upper frame and the lower frame and arranged along three generally perpendicular axes, the plurality of links including:
• one elongate link extending along a lateral axis generally parallel to the first horizontal axis;
• three elongate links extending along a fore/aft axis generally parallel to the second horizontal axis;
• and
• two selectively length-adjustable links extending along an axis generally parallel to a third vertical axis.

An asphalt paver screed comprising:

• a main screed;
• an extender screed;
• a linkage mechanism interposed between the extender screed and the main screed and including a linking frame connected to and extending rearwardly from the main screed to permit the extender screed to selectively extend laterally outward relative to the main screed and further including a supporting linkage comprising:
• at least one elongate link having a first end rotatably connected to the extender screed and a second end rotatably connected to the linking frame, the link extending along, and substantially limiting movement of the extender screed relative to the main screed along, a lateral axis generally parallel to a first horizontal axis and generally perpendicular to a direction of travel of the asphalt paver screed along a second horizontal axis;
• and at least one elongate link having a first end rotatably connected to the extender screed and a second end rotatably connected to the linking frame, the link extending along, and substantially limiting movement of the extender screed relative to the main screed along, a fore/aft axis generally parallel to the second horizontal axis;
• and
• at least one selectively length-adjustable link having a first end connected to the extender screed and a second end connected to the linking frame, the length-adjustable link extending along, and substantially limiting movement of the extender screed relative to the main screed along, an axis generally parallel to a third vertical axis perpendicular to both the first and second horizontal axis.