Coining press explained

A coining press is a manually operated machine that mints coins from planchets. After centuries it was replaced by more modern machines.

Presses came in multiple shapes and with different accessories (to collect the coins, etc.) They were made of cast iron. The basic elements are:^{[1] [2] [3]}

• A triumphal arch with a built-in base
• A vertically arranged leadscrew that supported an inertia wheel or more commonly, a piece made up of two radial arms with weights at the ends.
• The leadscrew (male) rotates inside a threaded (female) nut. The nut is attached to the structure. The turn of the inertia wheel (or bar with weights) determines the rotation of the thread bar and its vertical displacement (up or down depending on the direction of rotation).
• Vertical guides allow vertical displacement of the holder (upper die) without rotating.

Operation

Each coin is formed in a single operation. The press holds two negatives (molds that show each side of the coin) The body (material from which the coin is to be formed) is placed on the lower negative and the upper negative is lowered to create pressure sufficient to emboss the negatives onto the body. The upper negative descends directly without turning, pushed by a threaded bar that rotates, turned by a lever, compensated by an anti-torsion system. It is called a cold deformation as no heat is applied.^[4]

History

Before the press, coins were minted with a hammer:

Bibliography

• Book: Burke, James . 1985 . The Day The Universe Changed . registration . Boston . Little, Brown . 12049817 .
• Book: Cribb . Joe . Cook . Barrie . Carradice . Ian . 1990 . The Coin Atlas . registration . New York . Facts on File . 19456971 .
• Book: de la Portilla . J.M. . Ceccarelli . Marco . amp . 2011 . History of Machines for Heritage Engineering Development . New York . Springer . 729875665 .
• Grier . John A. . A Familiar Chat About Our Mints . Modern Machinery: A Monthly Journal of Mechanical Progress . 3 . January–June 1898 . 326 . Chicago . Modern Machinery Publishing . 1713651 . July 14, 2014 . .
• Book: Linecar, Howard . 1971 . Coins and Coin Collecting . Feltham, New York . Hamlyn . 667688 .
• Book: Porteous, John . 1969 . Coins In History . registration . New York . Putnam . 44608 .
• Book: Price . Martin Jessop . 1980 . The Nature of Coinage . Coins: An Illustrated Survey . New York . Methuen . 6194437 .
• Book: Yeoman, R. S. . Bressett . Kenneth . 1981 Handbook of United States Coins with Premium List . 38th . 1980 . Racine, Wisconsin . Western Publishing . 754090776 .
• Book: Yeoman . R. S. . Bressett . Kenneth . ——— . ——— . 2007 . A Guide Book of United States Coins . registration . 61st . Atlanta . Whitman . 123445484 .

Notes and References

1. Book: [{{google books |plainurl=y |id=SS4fPq7wFuEC|page=103}} Obra numismàtica esparsa i inèdita de Joaquim Botet i Sisó]. Joaquim Botet i Sisó. Joaquim Botet y Sisó. Institut d'Estudis Catalans. 1997. 978-84-7283-379-1. 103–.
2. https://www.raco.cat/index.php/BoletinRABL/article/view/201789/276522 Notícia del volum tercer del "Tratado de las monedas labradas en el Principado de Cataluña por el Dr. D. Josef Salat"
3. Book: Jean Boizard. [{{google books |plainurl=y |id=8usOAAAAQAAJ|page =145}} Traité des monoyes, de leurs circonstances & dépendances]. 1711. Chez Jacques Le Febvre . 145.
4. Book: Robert William Cochran-Patrick. Records of the Coinage of Scotland: From the Earliest Period to the Union. 1876. Edmonstron and Douglas. 49–.