John Mark Dastrup

US Patent:

40488250, Sep 20, 1977

Filed:

Dec 29, 1975

Appl. No.:

5/644554

Inventors:

John Burke Dastrup - La Jolla CA
Paul Oscar Green - San Diego CA

International Classification:

B21D 304

US Classification:

72 12

Abstract:

There is disclosed a machine for the cutting of reinforcing bar which is received in coils into straight lengths. The machine includes a coil unwinding station with an independent drive means for unwinding of the coil of reinforcing bar which is controlled in response to the slack in the re-bar unwound from the coil and in response to the lengths of re-bar cut by the machine to compensate for the large mass and inertia of the coil, interfacing the coil unwinding to the remainder of the machine operation. The unwinding station includes a slack detector responsive to the uncoiled angle of the re-bar to actuate, through roller cams, switches which control the drive for the coil spindle between power-on and power-off with braking or no braking operations. The re-bar is passed to straightener stations which are provided with a plurality of opposed rollers in orthogonal planes which are fixedly adjustable to bend the re-bar past its yield point in a direction opposite to the incident bends of the re-bar as it is received from the unwinding station. The re-bar is forced through the straightener stations by first and second drive stations that are positioned before the first straightener and after the second straightener stations.