The article is devoted to the dynamic study of the underground shovel’s working tool mech-anism, assembled in accordance with a crank-rocker scheme, containing curved wings, as well as to the study of the effect on uneven movement rate, produced by the working tool mechanism; pa-rameters and structural characteristics of the shovel paw design shape. On the basis of a synthesis of the loading machine’s working tool mechanisms, a kinematic scheme with a shovel paw, con-sisting of a straight operating part and a curved working tail, is offered. A dynamic model of the mechanism based on a variable weight of shovel bulk cargo and drive parameters of the working tool is developed, a motion equation is made up. Comparison between statistical indicators of effec-tive output obtained from the shovel loaders drive mechanism and the results of a separate computer simulation of the mechanisms under analysis attest to the proposed model’s performability.