Sunshine Kids letter to NHTSA

What Goes Into Making a Good...

...Child Restraint

By Dave Clement, PE. Director of Engineering, Sunshine kids

This question reminds me of questions regarding how to raise a good child. There is a wealth of information for "how to" raise a child, but the key ingredient needed as a parent and as a child restraint engineer, is PASSION. Without passion in both scenarios, the final product will most likely have problems.

Like parenting, consumer product design is a careful balance of requirements that times often conflict with one another. In general, for a consumer product, aesthetics or the industrial design have to mesh with the requirements of functional product performance and mechanical engineering requirements. Many consumer products have very few requirement. Several have very complex requirements stipulating that the marriage between aesthetics and performance be a healthy balance. All of these factors have to fit into a particular cost structure that is both appealing to the consumer and to the manufacturer.

One such product application is a child restraint intended to be used in an automobile.

In the world of designing child restraints, there is always a need to push the design constraints to their limits.

The mandatory requirements of consumer product design are usually dictated by our local and national government regulations. Child restraints have to meet strict federal guidelines outlined in FMVSS 213 standards. Most product designers will also go the additional steps of designing to "recommended" practices. Typically those practices are outlined by professional societies such as SAE (Society of Automotive Engineers) and ASTM (American Society of Test and Materials). These standards are usually applied in the product raw material acquisition and product manufacturing process.

Integrated into a good child restraint design are the design requirements for the most important aspect – the occupant. Careful consideration has to be given to ensure the child is comfortable and safe and that the parent can easily utilize the restraint. Today's attachment requirements for lap, LATCH and top tether make designing a one size fits all restraint or other unique restraints.

The mandatory requirements for a child restraint are well known by the consumer as the "crash test". Applied to a child restraint, the crash test is a mock-up of a real world, very severe frontal collision. The child restraint is fitted with a crash test dummy, otherwise known as an ATD (anthropomorphic test device), and the crash test sled is than put into motion to simulate this very severe crash pulse. Stopping from 30 MPH may not seem like a severe deceleration event: however, the best analogy I can give is that this sled test replicates a car colliding head on with a fixed barrier. Fortunately many of us have not experienced such a severe accident. Most accidents allow longer deceleration distances and many occur at lower speeds effectively lowering the loads the occupants see in a majority of accident conditions.

Balancing the above mentioned requirements with the industrial design can be a significant challenge. Early in the design process, full scale models are produced to allow the industrial and mechanical engineers hands-on assessment of the product. This model is shown to a group of consumers to understand their impressions of the product. Their inputs are than incorporated into a second or third revision of the design. Having critical reviews by people not directly associated with the design generally is beneficial to the products success at the "point of sale".

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Stelvis said:

It should be fine to sell if you cut out the SL strap and make sure the person buying it can get a good seatbelt install....

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DahliaRW said:

So now is SKJP on par with Dorel?

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