roller board and arms
/ˈɹəʊlˌʌp ˈblaɪnd/
n
English · roller board and arms中文 · 滚轮板与连杆Español · tablero de rodillos y brazosFrançais · abrégé et pilotes
Bedeutung：Group of trackers and rollers connecting the keys of a manual to the corresponding pallets.