Heidelberg Windmill 10×15 Bevel Gear & Gripper Locking Disc Heidelberg Windmill 10×15 Bevel Gear & Gripper Locking Disc. Bevel Gear: Heidelberg Part #T1437. Gripper Locking Disc: Heidelberg Part#T1406. This item can be picked up from our warehouse in Lutz Florida.