Bentley R Type - Page 62

58
TnB
'R'
Tvpe BBnruBv.
The
lever
(2) has
inclined cams
formed
on the
face of
its boss,
these
cams
engaging,
through
the
medium
of steel
balls, similar cams
formed
on the
boss
of
another lever
(4). From
the latter
a
rod (5)
directly
actuates the
rear brakes
through
the
medium
of the
levers
{6)
and
(7),
which are
pivoted on
a bracket
bolted
to the
"X"
member
of the
frame, and
finally,
through the
rear
equaliser
(8)
mounted
on
a
bracket
suspended
from the
axle.
The
output
from the servo
is
taken
by one
of
the
two
rods (9),
according
to
whether the
car
is moving forwards
or backwards, to
the
lever
(1O). This
lever carries,
in
turn,
a balance
lever
(1 1), the lower
end
of
wtrich
is connected,by
the
rod (12) to
the rear brake
lever (7),
thus
augmenting
the direct
pedal
effort, while
its upper end
is
coupled
to the master
cylinder
(13), which
actuates the
front brakes.
'flic
dashboard
hand brake
(14),
is
mounted
under the
facia board,
convenient
to
the driver's
right hand.
The
ratchet
release is
so
arranged
that
should
it be inadvertently
knocked
or
pressed, the brakes
will not
be
released. In
order to
release the brakes,
the
trigger
must
be
fully
depressed
and held
in
this
position.
The
hand
brake
is
then
pulled,
"rif
"pplying
the
brakes, arid this
action frees
the
ratchet
permitting
the
brakes to
be
released,
provided
that
the trigger
is
still
held.
This
device
is particularly useful
in preventing accidental
release of the
brakes
when
the car
is parked.
To
obtain
this action,
the trigger
is not directly
connected
to the
ratchet
pawl, but
cornpresses
a
spring.
This
spring,
in
turn,
operates
the
pawl, but
is
only strong
enough to
move
it out of engagement
when
the
load has
been removed
by pulling on the
hand brake.
The
hand
brake
is
connected
by an enclosed
cable
(15),to a hori-
zontal lever
(16),
mounted on the
"X"
section
of the
frame which
provides the
required
leverage, and
is
in
turn
coupled
to
the rear
brakes,
through
the levers (7)
and (17)
and
the
rear equaliser.
The
same
rear brake-shoes
are used, therefore,
as for
the
pedal operation,
and the
application and
release of the
hand
brake
can
be
lightened
accordingly
by simultaneous
application
of the
foot brake.
Poseible
Variations.
As
already mentioned, the leverages
are
so
proportioned
that
the
total
braking
effort is distributed
in a
predetermined
ratio between
the front
and
rear brakes.
This
distribution will
be upset if the servo
brakes
are
allowed
to
become badly
out
of
adjustment, or
if
the
seivo,
for any
reason, fails
to
give its correct
output.
A less likely cause
would
be
oil or
grease
on
the brake linings.
The
need for
adjustment of the
rear brakes
will be
indicated
by
excessive travel
of
the hand
brake lever,
whereas
the front
brakes,
which
are
operated
by
the
servo
motor
only,
will
not affect
the hand
brake
or pedal
travel.