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3 Fundamentals of press design

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530 Solid forming (Forging)<br />

ejector<br />

electronic <strong>press</strong><br />

control system<br />

dial feed plate<br />

punch holder<br />

monobloc <strong>press</strong> frame<br />

punch holder<br />

link drive system<br />

Fig. 6.8.21 Vertical minting <strong>press</strong><br />

blank control and<br />

discharge device<br />

feed hopper<br />

channel can be swivelled out or moved completely out <strong>of</strong> the <strong>press</strong> for<br />

die change.<br />

In the following channel, the blanks are checked for diameter and<br />

thickness related defects, and ejected if found to be outside the permissible<br />

tolerance (Fig. 6.8.23).The standstill periods caused by <strong>of</strong>f-size blanks<br />

would seriously impair the efficiency <strong>of</strong> high-speed machines. Therefore,<br />

coin blanks with defects are automatically segregated in a control station<br />

while the machine is running. If a defective blank reaches the control station,<br />

the flow <strong>of</strong> blanks is interrupted. The interruption triggers a sensor,<br />

which disables further blank feed from the hopper by means <strong>of</strong> a stop<br />

cylinder. The gauge jaws are opened by means <strong>of</strong> a lift cylinder and the<br />

<strong>of</strong>f-size blank is ejected into a collecting tray. The gauge jaws return to<br />

their home position, the stop cylinder opens and blank feed continues.<br />

The described cycle takes only fractions <strong>of</strong> a second, ensuring a continuous<br />

supply <strong>of</strong> blanks and preventing production disruptions.<br />

Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998<br />

slide<br />

main drive

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