The ornamental design for a sprocket for conveyorbelts, as shown and described.
1. Sprocket for conveyor belts
1.1 : Perspective
1.2 : Top
1.3 : Left
1.4 : Front
1.5 : Right
1.6 : Back
1.7 : Bottom
Fig. 1.1 is a perspective view of the sprocket; fig. 1.2 is a top view of the sprocket; fig. 1.3 is a left side view of the sprocket; fig. 1.4 is a front view of the sprocket; fig. 1.5 is right side view of the sprocket; fig. 1.6 is a back view of the sprocket; fig. 1.7 is a bottom view of the sprocket.