Warner Electric Blade Brake Clutch Application Guide - Manual (Page 5)

E. Clutch Actuation
A control system must be provided which will
allow the operator to engage the clutch by
rotating the actuation arm from the fully braked
position to the fully clutched position. This is
typically accomplished with a control in the
operator zone, which is connected by a cable
to the actuation arm. The control and cable
assembly must have sufficient stroke to rotate
the actuation arm from the positive stop in the
braked position to the positive stop in the
clutched position (17° nominal). Warner Electric
recommends the use of a cable with an
over-travel spring which will allow for mower
manufacturing tolerances. Cable manufacturer to
provide cable that will not stretch at required
force and to add strands as required.
F. Clearance
Adequate clearance for all parts of the BBC is
necessary for the BBC to function properly. No
member of the BBC should be constrained by
the mower deck, engine housing, or ground
drive pulley. Adequate clearance should be
available so that the brake plate may move
axially up to .375 inches (9.5mm) and the clutch
actuation lever may complete its required stroke
(dimension varies for different BBC geometries;
consult Warner Electric for assistance).
G. Engine Oil Drain Plug
All walk behind lawnmower engines contain an
engine oil drain plug somewhere on the block.
Some have the oil drain plug located directly
above the BBC. When using these types of
engines, Warner Electric strongly suggests that
the end user of the lawnmower be clearly
instructed to remove the engine oil out of the
downspout, and not the engine oil drain plug.
Figure 5 shows typical brake actuation return
spring mounting configuration. In figure 5, a
springthat provides a force of 60-lb (27kg)
tangent to (± 12°) and in plane with the
actuation arm rotation is attached at the brake
spring attachment point [located on a 2.56-inch
(66.04 mm) radius from the centerline of the BBC].
Option 2: When brake spring is attached to
one of the holes in the acctuator arm, it should
provide a minimum of 12kg (26lb) force tangent to
and in plane of rotation. When BBC is in clutch
mode this spring force is not to exceed 20kg
(44lb).
The blade brake feature of
the BBC requires a brake return spring that
will provide sufficient force to rotate the
actuation arm to the positive stop in the
braked position. Failure to fully rotate the
actuation arm to the positive stop for the
brake may result in increased blade stop
time and/or premature BBC failure.
5 Warner Electric • 800-825-9050 P-1319-WE • 819-0465
Figure 5