TABLE OF CONTENTS Automatic stops, or trigger stops, as they are sometimes called, register the strip at the final die station. They differ from finger stops in that they stop the strip automatically, the operator simply keeping the strip pushed against the stop in its travel through the die. For this reason, they are always used when an operator is to feed the strip by hand. Automatic stops can be made of cold-rolled steel or machine steel, cyanide-hardened, but when long runs are anticipated they should be made of tool steel, hardened machining. Design considerations include:
Fast, positive action under high-speed, shock conditions.
Minimum machining of the stripper plate for strength.
Sturdy, gadget-free design; automatic stops perform grueling service in operation, and weak design can be a source of trouble.
This chapter illustrates numerous standardized automatic stops with dimensions tabulated to help designers selects the right one for the conditions encountered. In addition, general rules are outlined to help with the correct application of these die components. This material further explains Step 9 in Chapter 5 Fourteen Steps to Design a Die.
Taken together, two plan views A and B, with a common side section-view C, illustrate the operation of a conventional side-acting automatic stop (Figure 14.1). At A, the strip has been advanced toward the left. Previously blanked strip edge D contacts the toe of the automatic stop, moving it to its extreme left position as shown,...
