UPSETTING MACHINES Publique Deposited
HOW AND WHY
The E-Sylum: Volume 7, Number 46, November 14, 2004, Article 22
UPSETTING MACHINES: HOW AND WHY
Dick Johnson writes: "I accept Chris Faulkner's request
for information on the upsetting machine. We cannot say
it was invented, it was more like "developed." But we
do know who should receive credit - Matthew Boulton!
If there is one person who was responsible for modern
coins and coining technology it was Matthew Boulton.Every numismatist should build a shrine to this one man
-- we would not have modern coins, or perhaps, modern
numismatics -- without this manufacturing genius. (I will
put his picture on my wall next to Leonard Forrer who is
my hero for compiling a directory of world coin and medal
artists, what I am trying to do for American artists).
[And a thank you also, to Dick Doty for his fantastic 1998
book on Matthew Boulton "The Soho Mint" - Dick, send me
your picture, I'll put it next to the others!]Before Matthew Boulton, coins were essentially struck on
the manual screw presses. Blanks were fed by hand one at
a time. I won't say it was a slow process, I was amazed
to learn they could strike as many as 20 to 30 a minute!,
as several men swung the arms of the screw press around
and back while the "coin setter" retrieved the struck coin
and inserted the next blank. They had great rhythm!Boulton took his partner James Watt's invention, the
steam engine, eliminated the men swinging the arms and
applied steam power to the screw press. Boulton learned
of Jean Pierre Droz's (and Gengembre's) invention at the
Paris Mint of an automatic feed and delivery system which
could be attached to the screw press. Boulton hired Droz
in 1790 for his Soho Mint in Birmingham (Droz makes
improvements, engraved some dies, but returns to France
nine years later).Existing blanks at first jammed the press (imagine those,
mint error collectors!) They needed blanks in quantity
that were uniform and perfectly round for automatic feed.
Cause of the trouble were the burrs around the trailing
edge of the blank from the blanking die shearing through
the metal strip.At first they hired young Birmingham boys, even 8 to 10
years old, to put a handful of blanks in a leather bag
and shake the hell out of the bag. The blanks knocked
against each other and "deburred" the edges. Remember
this is the beginning of the Industrial Revolution, so
they had to find a better IR way. They did this by
putting more blanks in a barrel and rotated the barrel
a process similar today called "barrel tumbling"
which is speeded up by adding steel balls smaller than
the blanks so they can be sieved out later]. This action
also deburrs the blanks.By 1797 Boulton's team had developed a machine he called
a "rimmer" " still called that in England today " here in
the colonies we call it an "upsetting machine." [I like the
British term better, but rimmer sounds too much like an
erotic toy for Americans to widely accept the term.]
Boulton's rimmer did five things: removed the burrs,
smoothes the edge, rounds the edge, made the blanks
perfectly round, and thicken the edge.Modern upsetting machines still do these five things. Mint
error collectors call blanks before upsetting "type 1" after
upsetting "type 2." Type 1 blanks are fed into an upsetting
machine and they travel in a channel on a spiral track
through ever smaller and smaller walls which forces the
blank's diameter to become less and less. The metal at the
edge builds up on both surfaces, thus making the blank
thicker around the circumference (ideal for raised rim
coins!).To answer your second question, Chris, who else uses
upsetting machines? I live near the Naugutuck Valley of
Connecticut where machine shops and metalworking plants are
on every block in every industrial area. I should ask some
of these. But the obvious answers are anything that is
"coined," that is stuck between dies at room temperature:
Buttons, small parts, washers, rings, the list is lengthy.
Some odd shaped parts are coined from round blanks because
of the ease and speed of striking these, then trimmed to
shape afterwards.I learned of the upsetting machine close up when Medallic
Art Company bought its first coining press in 1967. We
bought the press in Germany, but upsetting machines are made
in England (okay, rimmers!) and we couldn't get one right
away. My boss, Bill Louth, happened to mention this to Eva
Adams, then Director of the U.S. Mint. "We got some we're
not using," she said, "I'll lend you one." Sure enough,
until a new one came from England, we used a U.S. Mint
upsetting machine for upsetting blanks to strike medals!
The first of these were the Illinois Sesquicentennial
Medal of 1968 in silver dollar size."- 2004-11-14
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