Loading ...
Sorry, an error occurred while loading the content.

The origin of elliptical clips

Expand Messages
  • dermestid
    In the latest issue of Error Trends Coin Magazine, Arnie Margolis reprints two letters he received in 1973 from Alan Goldman, the mint s Assistant Director of
    Message 1 of 1 , May 28 4:58 PM
    • 0 Attachment
      In the latest issue of Error Trends Coin Magazine, Arnie Margolis
      reprints two letters he received in 1973 from Alan Goldman, the
      mint's Assistant Director of Technology at that time. The letters
      were in response to inquiries Arnie made regarding the original of
      elliptical clips.

      Mr. Goldman presents TWO scenarios, which are offered as guesses.
      Arnie has publicized and supported only one of these and told all who
      would listen that the favored scenario was an established fact.

      In his letter of March 12, 1973, Mr. Goldman says that "Most blanking
      errors occur from slippage of the strip during feeding. This causes
      the blanking dies to punch part of a circle which has already been
      punched before, producing a clip. If the previously punched circle
      still contains its blank, then the repunch produces two clips and an
      ellipse. Failure of the blank to separate from the strip can occur
      if the strip is too soft and "shags" at the edge."

      This scenario is very similar to the one offered by pwrwgndrvr and
      myself.

      The second scenario, presented in a letter dated July 5, 1973, is the
      one favored by Arnie. Mr. Goldman writes: "When a new punch and die
      set is inserted on a blanking press (as is done when changing from
      strip for one denomination to strip for another denomination), the
      initial length of strip is often fed through the press with an
      insufficient blow for the punches to penetrate the strip. This is a
      frequent occurrence during setup, when the tonnage is slowly
      increased until a sufficient force is acheived to punch through the
      strip without penetrating any further into the hole than necessary.
      An excessively long stroke would limit the speed at which the press
      can be run. The standard procedure is for the first several feet of
      strip after a change of denomination to be chopped and returned for
      remelting. Occasionally, particularly with some of the newer
      operating personnel, the strip is not advanced sufficiently to clear
      all the punches before the presses are restarted."

      So we see that even the mint itself is unsure how elliptical clips
      are created. As was made clear in a very long debate some months
      ago, I favor the first scenario.
    Your message has been successfully submitted and would be delivered to recipients shortly.