Presse

Modular vacuum chucks for various applications
-Combine single elements for large fixtures-

Purchase of a modern machining centre is preceded by a time-consuming process of comparison and decision.
Once selection has taken place the next decision must be made: how will workpieces be fixed to machine table? Which clamping method is most suitable for the job/s in question?
Cohn company, who amongst other things specialise in machining spiral springs on a subcontracting basis, were one of many faced with this decision.
Because our variety of workpieces covers mostly large aluminium parts with cutouts, which are difficult to clamp, the answer was easy: “For our applications only two clamping methods even came into consideration, and because we did not want to have additional support holes the only really acceptable method was vacuum clamping technology”, explained Manager Roland Funke.
The advantages of vacuum clamping technology are summed up by Dirk Overkamp, Dept. Head of milling technology: “Possibility of 5-side machining, a lot of clearance, time-savings and accuracy made it an easy decision for us.”
Cohn manufactures housings (rear panels and side panels) for laser machines. Some aluminium parts are as long as three metres, often up to 70% of material is milled out. Those kind of machining jobs are hardly possible using conventional clamping methods. However various requirements can be fulfilled easily


with vacuum clamping technology due to comprehensive system components and special solutions.
In Cohn’s case the best vacuum system was Vac-Mat from Witte, Bleckede, because it enabled complete machining in one clamping procedure.