Abstract: A coupling piece includes an abutment and locking member which is shiftable relative to the abutment to allow for an automatic and reliable locking of the containers. The coupling pieces do not jam when the connection is released by means of slightly tilting the upper container. The coupling piece is particularly suitable for automatically locking and releasing tightly stowed containers, especially 20' containers. In an alternate embodiment, a coupling piece is shaped such that the entire coupling piece is shifted to a locking position when containers are placed on top of one another.

Abstract: A rotary lock has a shank with a latch at each end mounted to be rotated in a housing. The latch has three positions with a basic position with both latches in a locking position being disposed between the other two positions in which one latch is locked and the other latch is unlocked. The lock includes a handle connected to the shank to move the lock from the basis position to the other two positions against a force of a single spring which biases the latches and shank back toward the basis position.