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<a href="http://revach.net/article.php?id=2392" eudora="autourl">
http://revach.net/article.php?id=2392</a><br><br>
<font size=3>The Shulchan Aruch (OC 313:6) discusses the circumstances
under which putting together beds and utensils that come apart, would be
assur on Shabbos because of Mileches Boneh, building. The Mishna
Brura (45) says that these rules do not apply to the “cover and lids” of
utensils, which may be freely opened or shut on Shabbos without any
problem. The reason is because the cover of a utensil is
meant to be opened and shut. Therefore closing it cannot be
considered building. <br><br>
Based on this Mishna Brura, the Pischei Tshuvos (3) says that Rav
Binyomin Zilber permits adjusting the height of an adjustable Shtender on
Shabbos even if it means loosening the screw and retightening it, because
the shtender is moved up and down all the time. Rav Vosner in
Shevet HaLevi (6:32) says that there is no question in this case because
the adjustable legs do not come off the Shtender, they always remain
together in one piece, and the shtender is always usable regardless of
the height.<br><br>
He also brings the Minchas Yitzchok (9:38) who is machmir and says that
since the shtender is sometimes left in the same position for a number of
days, it is not like utensil covers that are made to constantly open and
close. </font></body>
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