Patent ID: 6840393

Claim:
A crane assembly comprising: a bracket adapted to move along a rail and comprising: two side plates connected with each other and each having a bottom, an inner side facing to the inner side of the other side plate and an outer side; a first recess defined in the bottom of each respective side plate and corresponding to the first recess in the other side plate to form the side plate as an inverse U-shape; two axles mounted between the side plates and respectively located at two sides of the first recesses in the side plates to combine the side plates together; at least one wheel rotatably attached to the inner side of each respective side plate; and a first driving device attached to the outer side of one of the side plates and connected to the at least one wheel on the side plate on which the first driving device is mounted; a supporting plate attached to the axles and mounted between the side plates; a craning device pivotally attached to the supporting plate and having a top portion received in the first recesses in the side plates, the craning device comprising: a housing having a top partially received in the first recesses in the side plates; a second driving device attached to one end of the housing; and a craning mechanism received in the housing and connected to and actuated by the second driving device; a chain extending through the housing and connected to and driven by the craning mechanism, the chain having a first end provided with a hook and a second end; and a chain bag attached to the bracket for receiving the second end of the chain.