PURPOSE: To simplify the structure and reduce the cost in a captioned device by enabling loading and unloading of transport devices by means of the running power of a car, a conveyor, or others via a mechanism composed of cams, cam followers, links, and others for disusing a power machine.

CONSTITUTION: A pallet 16 with a load 17 loaded is placed upon transfer bases 7 on links 6a and 6b erected almost perpendicularly. At this state, when an empty conveying truck 1 is made to run as an arrow A shows to pass between transfer bases 7 and 7, it passes through without hindrance, since front cam plates 15 are below cam followers 9b. Meanwhile, rear cam plates 14 are brought in contact with cam followers 9a at its guide edges 14a to push, and links 6a and 6b are turned clockwise. At this stage, since cam followers 9b are brought in contact with cam plates 15, the transfer base 7 can be brought down smoothly. Then, when links 6b are inclined until they are in touch with stoppers 13, the load 17 on transfer bases 7 is transferred onto the truck 1 together with the pallet 16.