Use of a Gavel in the Synagogue to Silence the Congregation

We have a large synagogue, and we want to introduce a gavel, like that of judges. It is a completely mechanical gavel that makes a sound when struck on a designated surface, and thus the congregation will quiet down before the cantor begins the new section. The question is whether it is permissible to use it on Shabbos?

Ideally, it is appropriate to purchase a special gavel for Shabbos, and a regular gavel for weekdays, and that way there will be no problem.

Remo (Orach Chayim 338:1); and the Mishnah Berurah (subsection 7) wrote that there are communities that use a tool specially designated for Shabbos.