Moving punches and shear blades almost double the thickness capacity, and servo drives with PLCs change hole spacing and length on the fly at 600 FPM.
In-line rotary punching for roll forming lines is nothing new. Technology patented by Hill Engineering, Inc. a half a century ago continues to operate profitably, particularly in the production of wall studs. The rotary punches are simple, reliable, relatively low cost and can keep pace with the fastest forming lines - up to 600 FPM.
Nevertheless, the design imposes limitations. The maximum practical thickness is 0.60 in. (16 ga.) because the punches are stationary on the arbor. They enter and exit at an angle, causing interference between the punches and the edge of the strip as the thickness increases. And the punch spacing is fixed; the distance between holes cannot be varied.
Hill Engineering has solved both problems in one fell swoop. The Villa Park, Illinois, tool and die specialist - a Mestek company - has developed what it calls the B&K rotary punching and shearing machines that process strip up to 0.105-in. thick (12 ga.) and vary both hole spacing and cutoff length. There is no sacrifice of speed; 600 FPM is well within their capability.
Hill's B&K rotary punches and shears are being marketed to the steel framing industry, for the manufacture of products ranging from 2x4 drywall studs to large structurals. While the punch and shear are integral to the new computer controlled Supermill engineered by Dahlstrom Industries, Cleveland, Ohio (also a Mestek company), the units can be retrofitted to any make of roll former.
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