GMT history – Manufacture of Hand Operated Chucks
PV was looking for a chuck design which is far superior than the Scroll Type. Although Reishauer and Forkardt manual chucks were available by import at that time their design were different and manufacturing them were difficult as it involves special machines which cannot be used for any other operation except for making components for these chucks.
Berg chuck with worm and worm wheel design
Through Voltas PV imported Berg Chuck from Germany. On a study of its design he found the chuck is unique because of its worm and worm wheel design and steep rise and fall of cam. This design has high mechanical advantage for machining castings and forgings. In those days castings and forgings were so uneven on outer surface during machining intermittent cuts will emerge. To deal with such machining parameters high gripping force chucks are the only answer.
Voltas were representing Gildemeister Germany who are manufacturers of Multi Spindle Chuck and Bar Autos. Berg Germany were associated with Gildemeister for work holding. In 1963 GMT signed agreement with Berg for the manufacture of Manual Chucks…the rest is history