47
PIVOTING ZONE START BRAKE
PIVOTING ZONE START BRAKE
(DuraForce En
ines Only)
Introduction
In 1982, the federal
overnment mandated that all
consumer walk behind mowers with a cut of 25" (63.5
cm) or less be equipped with safety devices. There are
two primary criteria which these devices must meet:
1. A two-step operation must be performed in order to
start the blade rotatin
.
2. The blade must come to a stop within three
seconds of the operator leavin
the operator’s
position.
One of the ways the Lawn-Boy Corporation met these
requirements was with the “zone start system.” This
system utilizes a kill switch and a brake, which stops
the en
ine when the operator releases the blade
control bail (A). (See Fi
ure 86.) The two-step blade
en
a
ement criteria is met by requirin
the operator to
pull the bail to the handle first, then pull the recoil rope
from the operator’s position.
Fi
ure 86
0893-048
Operation
The pivotin
style zone brake system has two main
functions. The first function of the system is to stop the
production of spark and the second is to stop the
en
ine and the blade.
Stoppin
spark production is controlled by a switch.
The switch is closed when the blade control bail is in
the “at rest” (vertical) position. (See Fi
ure 86.)
Lowerin
the bail to the main mower handle opens the
switch.
Switch leads are connected to the primary side of the
coil and to
round (see Fi
ure 87). When the switch is
closed, the electronic i
nition module is bypassed so
that it cannot interrupt primary current flow. This action
prevents the coil from producin
the hi
h volta
e
necessary to
enerate spark. When the switch is
open, the i
nition coil produces spark.
Fi
ure 87
0893-043
Stoppin
the en
ine and blade is accomplished by
means of a brake that is applied to the flywheel. The
brake sprin
is in the “braked” position when the blade
control is in the “at rest” or vertical position. When the
blade control bail is lowered to the mower handle, the
brake is retracted and allows the en
ine to run.
A
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