Abstract: A lift vehicle comprising a carriage propelled by a drive wheel system having a drive wheel rotatable about a drive axis relative to the carriage, a lift structure connected to and supporting a load carrying frame and configured to raise and lower the frame relative to the carriage, a lever linkage connected to and supporting a traction load component of the lift vehicle, the linkage coupled to the carriage at a pivot connection and coupled to the drive wheel at a drive wheel connection, the linkage rotatable about a pivot axis relative to the carriage at the pivot connection and the pivot axis offset from the drive axis by a pivot-to-drive offset distance, the traction load component supported on the linkage a pivot-to-load offset distance from the pivot axis, and the drive axis configured to rotate relative to the carriage about the pivot axis to engage a travel surface.

Abstract: A jam-tolerant dual-redundant differential-summing actuator (20) includes a first driver (23) adapted to be rotated about a first axis (x1-x1) at a first surface speed; a second driver (26) adapted to be rotated about a second axis (x1-x1) at a second surface speed; a movable output member (21); and a linkage (24, 28, 31, 32, 33, 34, 40) connecting the first and second drivers to the output members such that the output member will be moved at a velocity that is substantially proportional to the average surface speed of the drivers.

Abstract: An oven includes a plurality of pairs of upper and lower spaced non-focused infrared heater panels. Product is conveyed between these panels to effect solder reflow. To increase heat transfer and to achieve temperature uniformity, air is forced through equally spaced holes drilled in the insulating block of one or more upper heating panels. To define an equal flow through these holes, a valve is placed below the air intake opening to define an annular opening between the panel casing and the valve. The valve has openings having an area which is matched to the annular area between the casing and the valve.