Abstract: A sprocket wheel or double helical gear loader for a machine which generates gears by pinion shaped cutters. The machine includes a gear bearing table having a centering device and a rotatable supporting base. The loader includes a turntable which advances step-by-step about an axis of rotation of the base. The turntable includes on its periphery a plurality of gear holders, which can be intermittently positioned at cutting stations and a discharge station of completed gears. A gear is secured to the turntable through gripping arms, which surround the gear about a whole of the gear perimeter except for an aperture. A cutter passes through the aperture. The gripping arms are movable to accommodate gears of different sizes.

Abstract: Centering device acting upon an already present first ring (14a) of a straight or double helical toothing of gears, sprocket wheels or pulleys to obtain the second ring (14b) of the toothing generated by a pinion shaped cutter (16), a central groove (19) separating said first ring and said second ring. The centering device comprising a retractable pin (20, 120), cooperating during the positioning step of the gear (13), with at least a tooth (15) of the first ring (14a), having a first waiting position (20a, 120a) and a second operating position (20b, 120b) defining the angular position of the gear (13) clamped on the rotary supporting base (18), the angular position being functionally correlated to the plane which contains the axis (25) of the gear (11) and the axis (26) of the cutter (16).