NEW Head and Neck Restraint Launching at PRI

appears to be a slightly redesigned Hans.


As far as what you mentioned about comparing your results to other manufactures I completely understand, and agree. Just wondering why most companies don't purchase the competitions HNR and then test them in the same manner that they believe is best and publish the data. Is it that they are all pretty close that you might end up giving the competition free advertising? I am assuming you guys purchased a few of the competitions and already tested them to get a base line starting point of where your sits.

Not directing the question just at "defNder tech," wondering about all HNR companies in general, although since HANS has the grasp on the market they probably just don't bother.
 
>> Although all the products have been tested to SFI38.1 protocols, the setup of each device can bring in variation that would account for the difference between our performacne and theirs. ...

So I think what I'm hearing here is that you believe the reliability of the 38.1 testing protocol is such that it doesn't actually have the discriminatory power to tell performance of one H&N system from another? That the test-retest repeatability error is large enough that it's greater than the anticipated measured differences in performance outcomes among systems?

K
 
The SFI test is consistant and reliable. The SFI has ensured that as many variables in the test rig have been reduced so that the "device" used on the test rig is tested and not the test rig itself.

We have started a testing page to our website and have currently got some testing photos up with testing data to follow before the PRI.

To date we have not tested other manufactures devices as even if we did test them and publish the results, without credible witnesses the results would always be questioned. For the same reason we would not compare our results to another manufacturer as we were not there to witness and varify their testing and results to be able to compare them directly.
 
defNder tech said:
The SFI test is consistant and reliable. The SFI has ensured that as many variables in the test rig have been reduced so that the "device" used on the test rig is tested and not the test rig itself. ...
Click to expand...

So three different tests of the same device, under the 38.1 protocol, yield test results that are considered "repeatable." Why would single tests of three different devices be any different?

The whole point of a "test protocol" is to assure that it's reliable enough to generate data that are comparable, among tests. It's either good enough to use as a basis for comparison or not. And "approval" is comparison to some benchmark performance - presuming the protocol is in fact performance-based.

K
 
Ok so it comes in cool colors here are a couple of things I would like to know. Is it made in the USA? What is it made of? Looks like fiberglass to me. To me it looks like it would put a lot of presure on the lower part of the device in a impact. That would be right on your chest. I'm sure the crash dummy used to test the device does not care about it but I might. Any thoughts on that? The rear back piece looks pretty low and looks like it might get hooked under a helmet. It sure looks a lot like the same design concept as the HANS. Wonder what they think about it?
 
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Bob, it does appear very HANS-like, and that is NO surprise, as the SFI spec was written with help from the HANS folk, and limits the design architecture of any device that is to pass. The limits are specific in the mandating of a "yoke" device.

It's also no surprise that this unit appears (and I use the term "appears", because the photos are rather dramatic, yet un-revealing, probably by choice), to incorporate some elements to improve on the HANS' failings in the belt retention area.

I'm confused by the companies stance that test results aren't to be considered valid unless they were there as witnesses.

Isn't that the point of hiring Wayne State et al to do the testing? Impartial 3rd party oversight? The implication is that the results are suspect, and that implies meddling. How can such manipulation enter the process??
 
I'd consider the R3 to have a yoke, obviously a different design than the HANS, but a yokelike unit, nonetheless.
 

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The material that the defNder is made from is a Dupont Composite Nylon which they have developed extensively to replace traditional materials like aluminium etc ie high strength to weight properties.

The chest displacement of the defNder is in fact less than the baseline tests. This is achieved by the tether geometry which allows for very low resultant torque on the front lower end of the defNder. The stabiliser bar (green part) is partially flexible and not a rigid member, as it is not having to counter a torque from the tethers and so translates into low chest pressure, chest compression and V*C. This is very different to other devices.
 
lateapex911 said:
I'm confused by the companies stance that test results aren't to be considered valid unless they were there as witnesses.
Click to expand...

I think what he is saying is that if Company X tests Company Y's product, how can X make a statement about Y unless it is witnessed.

I have never seen any "raw" data from Wayne State or Delphi (maybe I need to join SAE or something?), only data cited by the manufacturers.
 
I guess I'm naive, but I thought the whole point of paying the big money to Delphi or Wayne State was to have them be the unbiased tester/reporter. I give them the money, they perform the test according to protocol, and they give me the numbers. I'm merely there watching because I bought the tickets!

Seems simple. how could the numbers be unreliable?
 
John, let me detail my thoughts... I have used the term "yoke" when referring to the spec, and used quotes in doing so. I had lost my link to the 38.1, but did some digging, and here are the relevant parts;
Separate Restraining Devices:
A. Linkages attached to the helmet which transfer restraining loads directly
to the helmet from the main device which is secured to the driver's
shoulders, torso, etc. Methods for attachment of these linkages to the
helmet and main device shall be prescribed by the manufacturer.
B. The main device shall be a mechanism held tightly to the driver's torso by
seat belts or other strap systems such that the reactive load carrying
components move directly with the torso and controls head, neck, and
torso relative positions during forward or off-center impact situations.
2.3 Reaction Linkage: The means by which the head force necessary to limit
displacement of the head with respect to the torso is reacted. Acceptable
reaction linkages could include load paths to the torso or to the restraint
webbing. Direct attachment to react loads to a fixed point or points on a
vehicle structure or restraint webbing will not be acceptable because of the
potential for torso displacements with respect to these points. Imposed
loading by the reaction linkage to other areas of the body should be applied
using approaches demonstrated to be practical without imposing risk of
serious injury.
Click to expand...

Now, while it doesn't use the term "yoke", you can see that it mandates a "main device" that is strapped to the users body. The various R3 devices, and the HANS each have main devices, that many would consider "yoke-like".

The point remains that the specification is limiting, requires a certain component and attachment method, and excludes other possible solutions.
 
Let me add a personal experience to the discussion....

I was asked by a manufacturer of a head restraint system to take delivery of said system and deliver it to the Delphi testing lab. I was asked to do this because I am about 30 minutes from the lab and the manufacturer was unable to be there(it was NONE of the systems being discussed here).

After arriving at Delphi, the technicians there took it form me and proceeded to attach it to the dummy on the sled. They related to me that, because they conduct these tests on a regular basis and are most familiar with the equipment, they would handle it thank you very much. I was able to watch them attach it to the dummy and then watch the test conducted. After the test, the system was put back in the box I brought it in and handed back to me.

As I read all the comments and discussion of how these things are tested, who might be able to have an impact on how the test is conducted, who might be able to do something funny to skew the test, or any other nefarious thing, that voice in the back of my head keeps saying "that isn't possible, the testing lab would never allow that to happen."

I also had the opportunity to hear some conversations of un-named major players in that room that gave me some insight as to why some things are the way they are. I must say it was a most informative day.
 
Dave Burchfield said:
Jim........you will only see a report if it is in the public domain. If the manufacturer doesn't want you to see it, you won't.
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Dave, what's to stop me, for example, being the rich basta'd that I am, LOL, from taking a Defnder, and Isaac, a HANS and an R3 and paying Delphi and or Wayne State to sled them all, then publish my findings, as reported by those facilities?
 
Based on previous info Gregg has provided, nothing is stopping "anyone" from stroking a big check to Delphi or Wayne State and testing all the big H&N options. This issue is that the testing is not at all cheap. :(
 
lateapex911 said:
Dave, what's to stop me, for example, being the rich basta'd that I am, LOL, from taking a Defnder, and Isaac, a HANS and an R3 and paying Delphi and or Wayne State to sled them all, then publish my findings, as reported by those facilities?
Click to expand...
:rolleyes::shrug::026:
 
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