child seat & seatbelt notes

Notes on 850 Child Seats & Seatbelts

Eric's contribution to this discussion (sent September 2004) is a very important one, so it is highlighted and placed first.
Thanks again for this contribution to the OzBrick, Eric!

Dear Oz Brickie-

I just read the child seat info on your archive here and it was quite
helpful on the issue of the buttons coming off the belt. However, there
is a side issue here that may cause some people to dangerously
misconstrue how the seat belt works when used with a child seat.

This article at the the US Consumer Product Safety Commission Web page
describes the mechanisms:
<http://www.cpsafety.com/articles/lockincss.aspx>

The Volvo system is by far the best I've used, as one might expect. The
suggestion to augment this with a locking clip could compromise this
system and produce a dangerous situation. The seat belt is locked
during an accident by the Emergency Locking Retractor (ELR) in the seat
back, not by the locking mechanism in the buckle. The locking
latchplate merely holds the belt in a pre-tensioned state so that,
during an accident when the ELR is activated, the belt is maintained in
a tight position. The mechanism in the latchplate serves no function
after the ELR is activated, so it cannot fail in an accident.

An auxilliary locking clip performs the same function in a far less
satisfacory manner. These clips have no strength and are anticipated to
fail in an accident. When it is installed is such a manner that, when
it does fail, the belt becomes slack (eg at some distance from the
buckle), then the ELR cannot perform its function. As there is nothing
to fail in Volvo's system, using a clip in addition to the locking
latchplate is not simply redundant, but opens the possibility of an
unsafe installation. There are beefier clips, used as belt shorteners,
that are designed to take the force of an accident, but these are not
commonly seen or used.

On most new cars, the ELR is converted into an Automatic Locking
Retractor (ALR) that cannot be pulled out from the wheel once the ALR
is activated. In this system, the belt is already locked before an
accident, and the latchplate does not need to lock. However, I find
this system quite hard to use since all the slack in the belt must be
fed into the retractor while holding the seat in place. Volvo's locking
latchplate allows you to pull upward directly at the buckle and then
feed the slack into the retractor without worrying about the seat
shifting.
--
Eric Salathe
Climate Impacts Group
University of Washington
http://www.atmos.washington.edu/~salathe

... posted by Adam Rosenfeld on Monday, 15 January 2001, at 9:07 a.m.

                       I just had the common problem fixed of the rear seatbelt getting stuck because it was retracted too far.
                       After a trip to the dealer and having them install new "buttons/stopper" on the belt, I went home to
                       reinstall my son's child seat.

                       When I reinstalled the child seat, I was being VERY mindful of the position of that button on the belt. As
                       my seat is getting tightened, that rivet is right at the car's buckle. Then I put my knee on the seat and
                       shoulders on the roof and crank down like there's no tomorrow! PROBLEM IS, THE BUTTON
                       NEEDS TO GO THROUGH THE BUCKLE AT THIS POINT. THIS IS WHEN THE BUTTON
                       BREAKS OFF!!!

                       So what I did to prevent this was to unbuckle the seatbelt, feed the belt through to get the button out of
                       harms way, then with the knee and shoulder trick, get teh buckle back in (kind of how one puts in a seat
                       when using one of the locking clips, if your car didn't have the "child" position on the buckle that volvo
                       and saab have).

Then, once the belt is buckled and safely past the button, CRANK AWAY!

One last thing, I'll never put down my rear seats without checking to tsee if I still have those buttons in
place.

Just wanted to pass on what I've learned the hard way.

--
Adam V70 T5(M) - Now flashing upon lock AND unlock!

> and shoulder trick, get the buckle back in (kind of how one puts in a
> seat when using one of the locking clips, if your car didn't have the

                       I think you should still use the locking clip (pretty easy to slide
                       on once the seatbelt is pulled tight). There have been posts where
                       people report the buckle's parts that keep the belt tight have broken.
                       The buckle gives you a bit of insurance. I use the seatbelt to
                       pull the seat tight (and you can really get it tight) and then always
                       used the metal buckle.

--
Ray Niblett 95 855 GLT / 98 S70 T5M

... posted by Adam Rosenfeld on Monday, 15 January 2001, at 2:47 p.m. ...in response to "Re:
child seats and Volvo seatbelts!" posted by Ray Niblett.

                       I don't think we should use the locking clip in addition to the mechanism in the volvo seatbelt that
                       performs the same function. The clip is only for seatbelts that don't do what ours already does. I'd be
                       concerned the clip would interfere with the seatbelt during a crash.

Everything I've ever read points to doing whatever the particular carseat manufacturer tells us to do
BECAUSE THAT'S HOW IT'S CRASH TESTED.

Now, what specifically about the volvo buckle is proportedly failing? The buckle? The "child" locking
position? This would be a VERY serious failure!!!

Please advice further.

--
Adam V70 T5(M) - All in and belted. Now STEP ON IT!

... posted by Ray Niblett on Monday, 15 January 2001, at 5:15 p.m. ...in response to "Re: child
seats and Volvo seatbelts!" posted by Adam Rosenfeld.

                       The little red plastic part that slides back and forth on the
                       rear of the seatbelt buckle has been reported to break. This
                       would prevent it from being put into child-seat "mode". I don't
                       know if this represents a safety issue or not (mine have functioned
                       perfectly). But, the fact that it is plastic and has moving parts
                       makes me weary -- the metal clips are strong and reliable so I used
                       them in combination with the seatbelt child-seat mode (on our 98,
                       our 95 wagon belts do not have the child-seat mode switch).

                       I do find the child-seat mode made it very easy to cinch down the
                       child seat. I can get it much tighter then I ever could with
                       seatbelts that do not have this feature.

--
Ray Niblett 95 855 GLT / 98 S70 T5M

If you have any experiences, facts, hints comments or data that you think might be useful on the site, please

and I will post it, with an acknowledgement of your contribution (if you so wish).