Possible Clues:

• Round one, gripping -- good to punch bully with bit of a sock
• Source of jelly coating good part of mechanism
• Circular frame with series of projections round the rim
• Toothed circular frame
• Part of the machinery for getting engaged?
• Force in ox foot jelly with teeth
• Its teeth engage as it rotates
• Toothed gear
• Cheat with scoundrel, one engaged with others in revolution