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From: Mike Hunter on 31 Jan 2010 19:16
What is strange about all this is Toyota says dealers have not been able to
duplicate the problem. If that IS the truth then why are they scrambling
to get hold of 5.4 million new ones?


"Georgie" <remailer(a)reece.net.au> wrote in message
news:7AN6LJD740210.3274305556(a)reece.net.au...
> The return mechanism for the throttle pedal must never rely
> solely on spring force. Springs are alright as an assist, but in
> the event of spring weakening or excessive friction, positive
> means must be instintively available to safely return the pedal
> to idle.
>
> Stuck accelerator pedals are nothing new. Earlier mechanical
> linkages have experienced the same nasty failure mode.
>
> Here is what I recommend:
>
> 1. Redundant springs. Two springs working in tandem. If one
> snaps or stretches, the other remains effective.
>
> 2. Relocate the pedal fulcrum. Instead of pivoting the pedal at
> one end, locate the pivot at 1/3 from the lower edge. The pedal
> then becomes a rocker design. If for some reason, it sticks,
> heel force can be employed to rock the pedal back to engine
> idle. Properly balanced, the pedal will normally operate with no
> perceptible difficulty, but now failsafe.
>
> 3. Use high quality, permanently lubricated ball bearings in the
> pedal assembly for lifetime frictionless operation.
>
>
>


From: raamman on 31 Jan 2010 22:53
On Jan 31, 6:51 pm, Georgie <remai...(a)reece.net.au> wrote:
> The return mechanism for the throttle pedal must never rely
> solely on spring force. Springs are alright as an assist, but in
> the event of spring weakening or excessive friction, positive
> means must be instintively available to safely return the pedal
> to idle.
>
> Stuck accelerator pedals are nothing new. Earlier mechanical
> linkages have experienced the same nasty failure mode.
>
> Here is what I recommend:
>
> 1. Redundant springs. Two springs working in tandem. If one
> snaps or stretches, the other remains effective.
>
> 2. Relocate the pedal fulcrum. Instead of pivoting the pedal at
> one end, locate the pivot at 1/3 from the lower edge. The pedal
> then becomes a rocker design. If for some reason, it sticks,
> heel force can be employed to rock the pedal back to engine
> idle. Properly balanced, the pedal will normally operate with no
> perceptible difficulty, but now failsafe.
>
> 3. Use high quality, permanently lubricated ball bearings in the
> pedal assembly for lifetime frictionless operation.

I like the rocker idea- good show
From: Ray O on 31 Jan 2010 23:53

"Georgie" <remailer(a)reece.net.au> wrote in message
news:7AN6LJD740210.3274305556(a)reece.net.au...
> The return mechanism for the throttle pedal must never rely
> solely on spring force. Springs are alright as an assist, but in
> the event of spring weakening or excessive friction, positive
> means must be instintively available to safely return the pedal
> to idle.
>
> Stuck accelerator pedals are nothing new. Earlier mechanical
> linkages have experienced the same nasty failure mode.
>
> Here is what I recommend:
>
> 1. Redundant springs. Two springs working in tandem. If one
> snaps or stretches, the other remains effective.

The challenge with double springs is that either twice as much effort is
needed to overcome the springs, and if the the return force is divided among
the two springs, then if one fails, there is still insufficient return force
to close the throttle. Of course, springs are not the cause of the
recall/stop sale.

>
> 2. Relocate the pedal fulcrum. Instead of pivoting the pedal at
> one end, locate the pivot at 1/3 from the lower edge. The pedal
> then becomes a rocker design. If for some reason, it sticks,
> heel force can be employed to rock the pedal back to engine
> idle. Properly balanced, the pedal will normally operate with no
> perceptible difficulty, but now failsafe.

The challenge is that the pedal is suspended from above and is more like a
pendulum so applying force on the bottom of the pedal would also open the
throttle. Having enough space at the bottom of the pedal between the floor
and the pedal might allow a foot to slip underneath and pull the pedal back
out but this would probably be difficult to do in a panic situation, and
large boots might not fit.
>
> 3. Use high quality, permanently lubricated ball bearings in the
> pedal assembly for lifetime frictionless operation.
>

This would be a good idea if the bearings were also sealed against moisture
and dirt.
--

Ray O
(correct punctuation to reply)


From: Mike Hunter on 1 Feb 2010 11:45
But, but, but bearing cost more money ;)


"Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
news:hk5ms6$8re$1(a)news.eternal-september.org...
>
> "Georgie" <remailer(a)reece.net.au> wrote in message
> news:7AN6LJD740210.3274305556(a)reece.net.au...
>> The return mechanism for the throttle pedal must never rely
>> solely on spring force. Springs are alright as an assist, but in
>> the event of spring weakening or excessive friction, positive
>> means must be instintively available to safely return the pedal
>> to idle.
>>
>> Stuck accelerator pedals are nothing new. Earlier mechanical
>> linkages have experienced the same nasty failure mode.
>>
>> Here is what I recommend:
>>
>> 1. Redundant springs. Two springs working in tandem. If one
>> snaps or stretches, the other remains effective.
>
> The challenge with double springs is that either twice as much effort is
> needed to overcome the springs, and if the the return force is divided
> among the two springs, then if one fails, there is still insufficient
> return force to close the throttle. Of course, springs are not the cause
> of the recall/stop sale.
>
>>
>> 2. Relocate the pedal fulcrum. Instead of pivoting the pedal at
>> one end, locate the pivot at 1/3 from the lower edge. The pedal
>> then becomes a rocker design. If for some reason, it sticks,
>> heel force can be employed to rock the pedal back to engine
>> idle. Properly balanced, the pedal will normally operate with no
>> perceptible difficulty, but now failsafe.
>
> The challenge is that the pedal is suspended from above and is more like a
> pendulum so applying force on the bottom of the pedal would also open the
> throttle. Having enough space at the bottom of the pedal between the
> floor and the pedal might allow a foot to slip underneath and pull the
> pedal back out but this would probably be difficult to do in a panic
> situation, and large boots might not fit.
>>
>> 3. Use high quality, permanently lubricated ball bearings in the
>> pedal assembly for lifetime frictionless operation.
>>
>
> This would be a good idea if the bearings were also sealed against
> moisture and dirt.
> --
>
> Ray O
> (correct punctuation to reply)
>


From: Mike Hunter on 1 Feb 2010 11:45
YA THINK?


"Elmo P. Shagnasty" <elmop(a)nastydesigns.com> wrote in message
news:elmop-DD5A6F.06501201022010(a)nothing.attdns.com...
> In article <7AN6LJD740210.3274305556(a)reece.net.au>,
> Georgie <remailer(a)reece.net.au> wrote:
>
>> 3. Use high quality, permanently lubricated ball bearings in the
>> pedal assembly for lifetime frictionless operation.
>
> And my guess is we'll find that Toyota told the supplier to "make it
> cheaper"--and the supplier found a Chinese bearing, probably pot metal
> that saved them three cents per assembly, that is the crux of this whole
> matter.


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