Abstract: A trailer bed having ground wheels at the rear and tractor engaging means at the front is formed of front and rear portions joined together by pivoted links, the rear portion being vertically movable relative to the front portion and the wheels to convert the trailer from a low-bed stepped configuration to a continuous flat bed configuration, and vice versa. A single cable is trained over pulleys on the bed portions and wheel mounts to effect simultaneous lifting or lowering of both ends of the rear bed portion.

Abstract: An outer tubular body member has a plurality of circumferentially spaced outwardly bowed spring fingers on its inner surface projecting downwardly to near the lower end of the body member and normally spaced apart. An inner tubular member is longitudinally movable in the body member and has a ring portion at its lower end surrounding the upper portions of the spring fingers and movable downwardly to cam the fingers inwardly to grasp a loose article in the well. Latching tongues on the spring fingers engage the ring when the fingers are cammed inwardly. In one form the body member is attachable to a drill string and the upper end of the inner member functions as a piston to be pushed downwardly by drilling mud from the drill string. In another form the inner member can be attached to the drill string and held in an upper position relative to the body member by shear pins which are severable by the weight of the drill string.