A push-pull DIY cutter for sheet material, such as mat and foam board, utilizes a blade-mounting handle that is pivotable from a null position in both of two opposite directions, so as to alternatively bring into operative position a blade element spaced to either side of the null position center line....http://www.google.com/patents/US5269212?utm_source=gb-gplus-sharePatent US5269212 - Mat cutter
