Take-up arm, load handling device and related storage and retrieval system

A take-up arm for a load handling device, the load handling device comprising:

• a body mounted on a first set of wheels being arranged to engage with a first set of parallel tracks and a second set of wheels being arranged to engage with a second set of parallel tracks, wherein the first set of wheel and second set of wheels are arranged on respective wheel mounts;
• a direction-change assembly comprising at least one direction-change mechanism arranged to raise or lower the first set of wheels and or lower or raise the second set of wheels for engaging and disengaging the wheels with the parallel tracks;
• and
• a plurality of drive belt assemblies each comprising a drive belt, a drive wheel, and a take-up arm, wherein the drive belt is routed around the drive wheel and a respective first or second set of wheels, wherein the first set of wheels and the second set of wheels are driven by respective drive belt assemblies, the first set of wheels and the second set of wheels being driven wheels,
• wherein each of the at least one direction-change mechanism is horizontally displaceable relative to the drive wheel and the driven wheels to raise or lower a respective set of driven wheels;
• and
• wherein each of the wheel mounts is vertically displaceable relative to the drive wheel to raise or lower the set of wheels, and
• the take-up arm comprises:
• a linkage arrangement having
• a first portion pivotally attached to one side of a respective direction-change mechanism, to move horizontally with the direction-change mechanism, and
• a second portion pivotally attached to a respective wheel mount, to move vertically with the wheel mount,
• wherein the first portion and second portion are attached at an elbow joint, and
• wherein the drive belt is further routed around the linkage arrangement, and the linkage arrangement is arranged to take-up slack in the drive belt.