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62 MACHINERY UPDATE JULY/AUGUST 2018 www.machineryupdate.co.uk
Feature: Automation, robotics and vision
A vacuum pick-up
head has overcome
several challenges
When vacuum
handling systems
company Simmatic
was approached
by motion control
specialist CR Solutions with a
request to develop a vacuum
pick-up head for a robot-based pick
and place machine, the application
sounded straightforward.
The head, mounted on the end
of the robot arm, simply had to
pick up five small boxes at a time
from an infeed conveyor and then,
after the arm had moved to the
appropriate location, deposit them
within a shipping carton.
As is so often the case, however,
the devil was in the detail, and
Simmatic had to overcome multiple
challenges on the way to devising
a successful solution.
The pick and place machine
was required to handle different
box sizes with varying heights.
All the boxes were small – no
more than 100mm per side – and
light in weight. The boxes were
shrinkwrapped but, because of
the fragile contents, an over tight
shrink wrap could not be used.
This meant that the wrap film
had seams and tended to form
bubbles, which made it more
difficult to lift the boxes reliably.
A key requirement was that the
pick-up head, complete with its
associated vacuum generator, had
to be small enough to fit inside the
shipping carton. The head also
had to be designed so that the
boxes could be placed right into
the corners of the deep shipping
carton, and there had to be no risk
that the head would damage the
carton in the process.
Products are packed in 20 sizes of box
Picking all
the boxes…
As the products
weren’t wrapped
tightly, the new
system had to
cope with the
resulting seams
which tended to
form bubbles
Simmatic carried out extensive
trials with sample boxes to devise
the most convenient, reliable and
cost-effective solution and its
engineers trialled an 80 x 500mm
lifting head, fitted with 21 lifting
cups arranged in three rows of
seven. Each cup was 15mm in
diameter, and was fitted with long
bellows to help accommodate
the varying heights and irregular
surface of the boxes.
GENERATOR IS COMPACT
The head was equipped with a
multistage vacuum generator,
powered by compressed air.
This compact device helped to
satisfy the requirement for a
head that would fit within the
shipping carton and, since it
has no moving parts, offered
the additional benefit of being
maintenance-free.
While this prototype head
worked well in most respects,
it was not able to position the
boxes right into the corners of
the shipping cartons, so Simmatic
developed a slightly smaller head
measuring 80 x 335mm which
was fitted with the same
arrangement of lifting cups as
the prototype.
The use of multiple cups was
a big benefit in this application
as, even if some of the cups were
not fully covered when lifting
boxes of a particular size, or the
irregularities in the shrink film
made it impossible for some cups to
achieve a good seal, the remaining
cups would still maintain good
vacuum, ensuring that the boxes
were lifted and transported
securely at all times.
T 01299 877770
W www.simmatic.co.uk