8999145EN: v1 26/02/2020
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Original instructions (ENGLISH)
Website: www.spearheadmachinery.com
5
Installation Checks
With the machine fully assembled, familiarize yourself with all the controls, start the prime mover and check for
leaks.
5.1
Breakout Checks
– Twiga Carrier CF30 only
Twiga Carrier CF30 breakout systems are designed for the purpose of providing initial protection to the mower
and its cutting attachment. This protection is to be afforded in the relatively rare circumstance that an
obstruction; unseen by the operator; is encountered during work.
Breakout systems are not designed as a complete protection system to remove operator responsibility. The
operator must always be in control. By breaking back the arm signals to the operator that an obstruction has
been encountered or that the operator is driving too fast for the cutting conditions. It is then the responsibility of
the operator to take appropriate action to prevent any further damage to the arm mower. Damage resulting from
continuing to work with the arm ‘broken back’ will invalidate warranty claims.
In most cases the speed of response required by the operator is proportional to the cutting speed. Operators
must therefore work responsibly and appropriately for the cutting conditions and within their own individual
capability. To monitor on going capability Spearhead Machinery endorses the maintenance of operator training
records.
There are several types of breakout employed on Spearhead machines depending on the duty cycle envisaged
for the machine. Take time to familiarise yourself with the breakout supplied with your machine. Make sure you
are familiar with its capability before commencing work. The different types are;
5.1.1
Hydraulic Breakout
On Twiga Carrier CF30 machines with hydraulically driven arm slewing
capability there is a hydraulic breakout which operates on the slew ram. In
the event that the cutting unit or arm structure sees a push back force so
pressure in the slew ram rises. A pre-set pressure relief cartridge
determines the degree of breakout force. Once the relief pressure is
exceeded the displaced oil is collected in a pressurised accumulator. This
oil stored under pressure is given back to the ram when the push back
obstacle is removed and allows the arm to ‘recover’ its former cutting
position automatically. Approximately 25 degrees of recovery is available
depending on slew ram and accumulator capacity; see Figure 5.1. Once
the accumulator is full and the arm is pushed further back then the arm will
need to be powered back into the cutting position.
CAUTION!
The accumulator bottle may hold residual hydraulic
pressure when not in use. Servicing or repair should only
be carried out by skilled hydraulic technicians.
WARNING!
The break out relief force is calculated for maximum
reach. As a result take care when cutting ‘close in’ to the
tractor as the mechanical advantage is reduced and the
force to breakout increases significantly. Be extra vigilant
and reduce forward speed. The fatigue life of the arm may
be shortened by repeated exposure to ‘close-in’ breakout
loads.
Figure 5.1
