Method of cutting gratings to length

A method of cutting off sections of a grating web of any desired length, said grating web comprising longitudinal elements and cross-bars, said method comprising the steps of

• (a) cutting said web by means of a shear introduced into the plane of said grating web, said shear having cutting blades in the form of comb teeth movable relative to one another;
• (b) establishing by means of a computer whether, at the distance from the last cut edge of said grating web corresponding to the desired length of the next section of grating required, there is a gap between said cross-bars to enable the introduction of said cutting blades into said grating web;
• (c) in the event of said computer establishing that there is a gap between said cross-bars, causing relative movement between said shear and said grating web over said desired length of said next section of grating required and cutting said web in response to a signal from said computer;
• and
• (d) in the event of said computer establishing that there is not a gap in said cross-bars, causing relative movement between said grating and said shear over a short distance and severing a short scrap section of said grating web in response to a signal from said computer, said length of said scrap section being calculated by said computer such that, at the required distance from said new cut edge corresponding with said desired length of said next section of grating required there is a gap between said cross-bars, and causing further relative movement between said grating web and said shear over said desired length of said next section of grating required and cutting said grating web in response to a signal from said computer.