402 / | HD | BINDER DEVICE RELEASABLY ENGAGING APERTURE OR NOTCH OF SHEET |
46 | DF | OPPOSED SHEET RETAINERS INVOLVING RELATIVE RECTILINEAR TRAVEL {4} |
48 | DF | .~ Telescopic retainers with means to telescopically drive and/or secure {4} |
50 | .~.~ Remote from retainer {1} | |
51 | DF | .~.~.~> Screw threaded means |