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The integrated
accelerator brake paddle system is a system for automatic
transmission vehicles since these types of vehicles are
controlled using two paddles
1)
Accelerator paddle and 2) brake paddle.
In integrated
paddle system only one paddle perform two functions of accelerator
and brake.
The system is made such that, when paddle is not pressed (released
fully), brakes of the vehicle remain applied fully so the vehicle
does not move.
As paddle is half pressed, the brakes are released as paddle is
further pressed then the accelerator is connected with the paddle
and paddle starts working as an accelerator paddle. If paddle is
again released till half pressed position again, acceleration
reduces to zero (idle ) position. When paddle is further released it
gradually applies the brakes. When paddle is completely released,
the brakes are fully applied .
The system should work better with power brakes or power assisted
brake systems.
The system is as shown in diagram I on the drawing page I.
In diagram I
'1' is a master cylinder of brakes system. '2' is a piston operating
inside the cylinder, '3' is a connecting rod that connects brake
system with the paddle. A spring '4' is fitted on the body of
vehicle. Rod '3' can move freely through the hole of guide '5'. The
spring '4' has enough tension so that the brakes are applied fully
as spring '4' pushes piston inside the cylinder and brakes are
operated. The paddle '9' (not shown complete in the diagram) moves
around axis shown as '14'. The paddle '9' is fitted with a cam at
it's axis as shown in the diagram. The cam moves with the paddle '9'
around axis 14'. Cam is shown as '8'.
The cam '8' has
a groove '7' on it's periphery. '6' is a follower, that moves along
groove '7' following the movements of cam ‘8’. Follower '6' is
attached to rod '3' as shown in the diagram I.
The shape of
cam '8' is as shown in the diagrams II, III, and IV on the drawing
page II.
When paddle is
not pressed, the brakes are applied completely (position A).
When paddle is
pressed, the cam '8' moves around axis '14'. Due to the shape of the
cam the follower '6' climbs up and as follower climbs, the brakes
are gradually released since the piston in the master cylinder is
pulled out.
When paddle is
half pressed (position C in above diagram), the follower climbs the
distance equal to the radius of the cam '8' and brakes are released
fully. Thus till position ‘C’ paddle is used as a brake paddle.
When paddle is
pressed further, brakes remain released due to semicircular shape of
cam ‘8’ and follower remains steady.
The movement of
paddle also moves limb '15' around axis '14'. When paddle is pressed
more than half pressed position (in position D, E etc.) the limb
'15' is connected with the accelerator '11' and accelerator is
pulled with the movement of the paddle. Thus now the paddle is
working as an accelerator.
When paddle is
released it moves from position E or D towards positions C and the
accelerator comes to idle position at C (diagram II on page II).
When paddle is
released further, the accelerator '11' is disconnected from limb
'15' and follower '6' climbs down from 'P' to 'Q' (diagram II).
As follower '6'
climbs down, piston '2' is pushed inside the cylinder by spring '4'
and brakes are applied. When paddle comes to position A the brakes
are fully applied.
When paddle is
released, it comes to position A due to spring fitted at the pivot
of paddle and the bracket in which pivot is fitted. The pivot,
bracket and the spring are not shown in the diagram.
Thus one paddle
is used for two functions of accelerator and brake of an automatic
transmission vehicle. The paddle operates with both the functions in
mutually exclusive way, thus when paddle is working as a brake
paddle, the accelerator is at idle status, and when paddle works as
an accelerator, the brakes remain fully released.
This system can
also be built using two paddles as shown in the diagram V on the
drawing page III.
Here brakes
system and the paddle ’9’ are same as above except it is not fitted
with limb '15' for accelerator.
A separate
accelerator paddle is provided which is same as conventional
accelerator paddle. Both the paddles are with limbs as shown in the
diagram V.
The accelerator
paddle has half pressing range (position C to E) whereas brake
paddle has movement range from position A to E. As brake paddle is
pressed to position C, the brakes are released, when brake paddle is
further pressed, the accelerator is also pressed due to overlapping
limbs of two paddles.
Thus virtually
the system is same as explained above since the driver controls the
vehicle using only brake paddle. |