Keilim 22:6-7
Keilim 22:6
If the middle slat of a chair was removed but the outer ones remained, the chair remains susceptible to ritual impurity. If the outer slats were removed but the middle one remained, it is likewise susceptible to impurity, though Rabbi Shimon says that this is only the case if that remaining slat is a handbreadth wide (about 3”).
Keilim 22:7
If two adjacent slats of a chair were removed, Rabbi Akiva says the chair remains susceptible to impurity but the Sages declare it insusceptible. Rabbi Yehuda says that if the slats of a bridal chair were removed but its storage receptacle remained intact, it is rendered insusceptible to impurity. Since the bridal chair’s primary function (seating) has been nullified, its secondary function (storage) is likewise nullified.