14
SEPTEMBER-OCTOBER2014
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BREAKERS
JCB’smediumHammermastermodels
– for the 86Cmidi excavator through to
5CXbackhoe loader – are all designedwith
a single-piecehardened cast-body that the
company claims is an innovativedesign
consistingof no tie rods or bodyparting
lines. The result, it says, was performance,
durability and reliability achievedby a single-
piece bodywith fewer points ofweakness.
Themediumbreakers also claim improved
efficiency andproductivityover theprevious
range.
TheHM386Qhas been specifically
designed for the JCB3CXbackhoe loader,
withgeometry claimed tobe optimised to
themachine, ensuring safe stowage and
transportation.
JCB’s largeHammermasters' features also
Into the fire
A customised 1,500 kg (3,300 lb)
Chicago Pneumatic RX22 hydraulic
breaker, designed for use with carriers
weighing from 17 to 28 tonnes, is being
used for kiln cleaning at the Caletones
copper mining settlement operated by
CODELCO, a state-owned Chileanmining
company.
Previously, a smaller 1,000 kg (2,200
lb) breaker was used in this application
but availability issues were common,
as was low hitting power. As a result,
frequent hose changing was required
and this in turn led to specialist mining
contractor Servicios Nettle Hermanos
suggesting the use of the RX22.
In special applications, such as the
high temperature working conditions
experienced in the Chileanmine, a longer
moil point can increase the productivity
of a hydraulic breaker. After receiving
the request for an RX22with a longer
workingmoil point capable of operating in
high temperatures, an feasability analysis
was conducted and engineers at Chicago
Pneumatic confirmed it was possible,
due to the lowmaterial resistance to
break, and that volumes were sufficient
to produce a bespoke solution for the
customer.
Commenting on the on-going
successful operation of the RX22, James
Nettle, marketingmanager for Servicios
Nettle Hermanos, said: ”Today the
breaker is working at optimum condition
without problems, and our customer is
very happy as a result. Since switching
to the RX22 the wear of the breaker
box has decreased, as well as hose
consumption, and the hydraulic breaker
now performsmore efficiently with less
parts used in the process.”
include JCBAutogrease as standard. This is
said to ensure that the breaker is correctly
greased togive smoother action and extended
bush life. This is further complementedby
adustwiper system toprevent dirt ingress.
They are also silenced as standard and claim
tobeup to5dBquieter than theprevious
range inoperation. This is particularlyuseful
in complyingwithnoise legislation inurban
environments.
JCB said that inorder togenerate
maximumpiston acceleration, the large
Hammermasters combinedhydraulic force
and recovered energy in thehydraulic system
through theuseof an efficient internal control
valve. Energynot absorbedby thematerial is
re-used in the followingblow, whichplaces
less demandon the carriermachine. The blow
frequency is increased and so theoutput of
thebreaker is also increased. Re-used energy
requires no additional hydraulic flow from
thepump, whichhugely improves efficiency,
ultimately saving fuel andmoney.
The latestDoosan range of hydraulic
breakers is designed for useonDoosan
wheeled and crawler excavators from14 to
38 tonnes, and the company claims superior
power-to-weight ratios toprovide efficient
reductionof rock, boulders, concrete and
other demolitionwaste, aswell as excellent
excavationwork.
Doosan said all its breakers shared the
same simple, robust designprovidingboth
economical and reliableperformance, low
maintenance costs, operator comfort and
ABobcat E26mini excavator sporting anHB
breaker attachment. All Bobcat breakers have a
silenced housing as standard
Volvo’s latest series of breakers – the
sevenmodel HB range – features a range
of technology including a damper to reduce
noise and vibration
