From the : Inside the Mint page on the U.S. Mint's website, article
by Adam Stump, deputy director of the U.S. Mint's Office of
Corporate Communications; used with permission
Housed on the first floor of the United States Mint at
San Francisco, a line of yellow robots move with
precision over a conveyor belt. Behind the clear acrylic windows, each
robot has a distinct mission assembling packaging and coins for
various proof sets.
The robots are part of the facility's Farason line, which was
installed in 2010. The robotics loop, one of the cutting edge
technologies used by the Mint, improving the quality and the rate of
production for the sets San Francisco makes. The old line could
produce at a rate of approximately 600 sets per hour. The new robotics
loop triples that output at a rate of approximately 1,800 per hour.
line has been busy in recent months making the last year of the
Presidential $1 coin series. The Presidential $1 Coin Program, which
started in 2007 and honored all deceased United States presidents,
will come to an end in 2016 when the United States Mint at San
Francisco mints the last coins.
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Packaging the 2016 coins once they've been minted, along with other
proof sets made at the facility, falls to a series of robots tucked
away in a corner of the San Francisco facility.
“The robotic loop makes us a technology leader,” said Dave Jacobs,
the plant manager. “The line helps package the coins for the largest
producer of proof coins in the world, the United States Mint at San Francisco.”
Justin Hatch, a packaging machine operator leader in San Francisco,
explained each of the robots and their purpose.
Robot 1 inspects the blister, or the pre-formed plastic insert. The
robot picks up the blister and holds it against a tracking camera,
which takes a picture and assigns a score to the item. If the score
meets quality standards, the blister moves on. If there's a quality
problem with the blister such as a scratch or crack, the item gets
sent down a slide into a reject bin.
Robot 2 takes off bottom trays and places them onto the belt. When
this robot places the trays, it attempts to place them parallel to the belt.
Robots 3 through 8 are called “pick and place robots.” Their job is
to pick up coins and place them into the trays. If the item is a three
coin set, only robots 3, 4 and 5 are working. The other three robots
are used for sets that involve sets with four, five or six coins.
Before each pick and place robot does their job, there's a tracking
camera that is inspecting the packaging and taking a measurement of
the orientation of the packaging. Since the packaging could slightly
move, the inspection cameras tell the robots to change the orientation
of the coin.
For example, if the packaging is askew at a five degree clockwise
shift, the tracking camera will take a photo and tell the robot that
when it's time to place the coin, the robot should shift the coin at a
five degree clockwise twist so when the coin is placed, the coin is
correctly oriented to the packaging. Since there's a tracking camera
before each of the pick and place robots, each robot may have to shift
to a different angle if there's any change to the packaging.
Robot 9 has a similar job to Robot 2, placing the top trays onto the
belt, and then comes Robot 10, which places the top lens onto the belt.
While the first ten robots are moving with a steady flow, Robot 11
is the fastest and busiest robot in the line. This robot has to grab
the insert, check it and place it into the lens set using a flipping
method. The robot inspects the lens and insert, makes contact with the
set to make sure the coin is at the proper height, places it into the
lens set and assigns a score to see whether the set is good or should
Robot 12 places the top lens, also assisting squaring and pressing
the set to make it secure.
The last stop is Robot 13, which picks up three completed sets in
succession and places them onto a trolley, which can hold 600 sets.
When Robot 13 is picking up the sets, each one can be skewed at an
angle up to 30 degrees and the robot will adjust accordingly to make
sure the sets are correctly placed into the trolley.
While the line has a success percentage in the high 90s and moves at
a rate approximately three times faster than the previous line,
there's still a need for human intervention, which is where the
employees come into play. San Francisco workers are needed to perform
maintenance, reset the machine if there's a stoppage, collect the
rejected blisters, coins and lenses, and replace any defective coins
that may have been damaged by the robot.
After the Farason line has assembled the lens sets, they move to an
adjoining room to marry up with the Certificate of Authenticity,
exterior carton and grouping into a box to get shipped to the
distribution line. The cartoning line, as it's called, has been at San
Francisco for about 10 years.
Overall, the Farason line greatly improves the speed and quality of
sets, ensuring customers receive the best product the Mint can make.