TPT September 2008

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September 2008 66
Technology Update
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AddisonMckee, has designed, built and
supplied two RidgeLock machines for
one of America’s largest manufacturers
of heating, venting and air conditioning
products (HVAC).
In a typical domestic or commercial heating
system, a heat exchanger is used to transfer
heat generated by burning oil or gas to the
air for distribution. The heat transfer tubes
contained within the system require precise
sealing to the heat exchanger panel in order
to prevent the escape of gases, and this is
normally done by means of a ‘RidgeLock’.
In the AddisonMckee RidgeLock process,
expandable segmented tooling is inserted
into the heat exchanger tubes (bent at 180°
into a sheet metal panel) in order to create
a rim that acts as a secure lock between the
tubes and panel.
For the customer in question, one
AddisonMckee RidgeLock machine
has been designed to perform locking
operations for small inner tubes (1.75" OD x
0.4" wall aluminised mild steel or stainless),
and the other machine performs the locking
operation on larger outer tubes (2.25" OD x
0.4" wall aluminised mild steel or stainless).
Both machines have been designed to hold
two sets of tools – one each for the end of
the tubes. A roller table located between
the two machines assists in conveying the
component assemblies.
AddisonMckee RidgeLock machines are
designed to perform locking operations
by use of a manual set up feature of a
micrometer stop nut on the cylinder to
control the machine. Tubes are expanded
by use of segmented fingers and a tapered
mandrel inside the tube to lock the tube
to the heat exchanger plate. The heat
exchanger assembly being ridge-locked
is then progressed manually along the
conveyor table between machine cycles.
In the ridge-locking process, the heat
exchanger plate is held down by electric
magnetics. The operator then positions the
tube in an alignment guide that holds the
tubes vertically during the forming process.
Air cylinders are then activated at the end of
the forming cycle to lift the plate assembly
off the tools and assist the movement
between cycles.
New ‘RidgeLock’ solution for HVAC manufacturer
 AddisonMckee has supplied two RidgeLock
machines to a US HVAC company
 The machines are used to perform locking
operations on heat exchanger assemblies