A corner notcher is basically a sheet metal working machine used to cut out a 90 deg section with a V shaped blade. The notcher is hydraulically powered and can take cuts in to a sheet of metal from a small cut of only 1mm up to 120mm in one operation. The corner on a sheet of metal can be cut out to provide clearance when the 2 sides may be folded up such as in a shallow tray or box. This clearance cut can be made in a single operation, within the limit of the length of the corner notching blade. The cutting action is the same as a guillotine, that is, top and bottom hardened steel blades acting against each other to shear the sheet metal.
This operation has largely been made redundant on simple sheet metal trays, boxes and brackets by the introduction of CNC punching. Corner notches can now be programmed to be CNC punched out in the sheet metal along with the holes, cut outs and the component’s outer profile. The notcher is however still very useful for certain materials and free issued components that cannot be CNC punched.
A typical application for the corners notcher is in modifying existing components among which may be spring clips, nails, sheet metal parts and plates. These components may be free issued from our customers needing to be modified to a new design level or where they have a front panel free with an enclosure and the need to use it for a different application.
You can see from the pictures on the right 2 typical examples of this work. One simple job is shown where we cut off nail heads to provide a cheap spike that can then be used by our customer after gluing it into a sign which are is used for signage on golf courses. There is another example shown of a free issued stainless steel spring clip that we cut back for our customer. In this case the stainless steel spring clips are used to hold a clear plastic cover on a light fitting and by cutting the spring clip back they become vandal proof for application in lighting public areas such as car parks, schools and underground walk ways.
We also manufacture stainless steel spring clips for several lighting companies that are used to keep lighting reflectors in place within their sheet metal housings. The spring stainless steel cannot be CNC punched and is only available in a small coil format so it still has to be processed with traditional manufacturing methods. We have to guillotine the coil into a blank size to suit the particular spring, use fly press tooling to pierce any holes and slots that are required and then cut any corner chamfers with the corner notcher. The example of the right here shows a typical lighting reflector spring clip.
So in conclusion, although the corner notcher is not used today for notching simple sheet metal work due to the efficiency of CNC punching with our Trumpf CNC punch presses, corner notching still has its uses. It is still used for peripheral sheet metal engineering applications such as those illustrated here.