On Thu, 22 Jan 1998 09:37:59 +0000 "Scott Gardner"
<gardner7@pilot.infi.net> writes:
>> US DOT regulations.
>> Requires the wipers to cover a specific percentage of the
>windscreen (I
>> don't remember the exact percentage). The twin wipers on the MGB
>and
>> Midget didn't cover enough.
>> SO, in their infinite wisdom, the boys at the works added another
>arm
>> and blade.
>> Incidentily, the triple blades were on roadsters. The GT with it's
>> larger windscreen and slightly longer wiper blades made the cut.
>> Rick Morrison
>> 72 MGBGT
>> 74 Midget
>>
>
>It also has to do with the geometry of the windshield wiper motor and
>arms on the 'B'. If you just had two 10" blades, but each one went
>through 180 degrees of sweep, you would have a total swept area of
>314 square inches, which would probably be enough to satisfy US DOT
>regs. Some trucks and airplanes use this type of semi-circular sweep
>pattern. Because the axis of rotation of the MGB wipers is so far
>from the blade, a third blade was the easiest way to go. To get a
>full 180-degree sweep, you have to have the shaft of the
>wiper motor exit the body right at the upper or lower edge of the
>windshield, and that just doesn't look right on most cars.
>Scott
Hmm,
Good point.
Rick Morrison
72 MGBGT
74 Midget
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