anglais vers français Technique / Génie Mécanique / génie mécanique shutter; hinge

-"A pair of sleeves are tightly inserted into the through-hole from each end of the hinge hub [...] adapted for cooperation with a shutter bracket pivot."
-"The upper sleeve is closed from the first end thereof with a blind flange comprising on the lower end thereof a pair of mutually spaced depressions adapted to accommodate said positioning pins of the hinge hub."

Peut-on parler de "manchon" ou "douille" ou bien de quoi s'agit-il dans ce contexte (volets) ?
Merci beaucoup.