----- Original Message -----
From: Phil Ethier <pethier@isd.net>
>
> For what kind of loads were stock seat-belt buckles designed?
The load on the lap belt (which is the part we were discussing) comes from
three points: radially outward from the body pressing against it (under
decceleration), and from the two ends (where it's attached to the car) which
resist the outward pressure. The seat takes quite a bit of the load in this
case, even when the body is trying to move forward. That puts a tension
load on the belt buckle, but not as much as would happen if using it as the
tail of a shoulder harness, which appears to me to place more of a load on
the strap -- now you're resisting the force imposed by the upper body
rotating forward, without the aid of the seat.
Of course, that's all back-of-the envelope -- with a crayon. But I still
wouldn't use a stock lap belt assembly as part of my shoulder harness.
Jamie
'92 Prelude Si
Speed Demon Racing
http://www.mindspring.com/~jsculerati/sdr
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