Из серии "их нравы".

The idea of the chair leg saw is based on the German proverb "To saw on someones chair leg", which means to try to get the job of someone who is more senior. The mobile chair leg saw is battery-powered and can be fastened at any chair. As soon as someone has a seat on the chair, the saw saws the chair leg.

http://www.cyberniklas.de/objekte/saege.htm