【化】 棘轮式千斤顶; 伞齿轮式起重器

automatic spiral ratchet screwdriver

spiral ratchet screw driver

pawl-and-ratchet type drive

heavy duty ratchet bit brace

lever switch with a ratchet mechanism

positive feed with pawl and ratchet of character-spacing mechanisms inselective printers

reversible ratchet handle【机】

screwdriver with ratchet action