ACTIVE' AIR HEADREST

Author: Boris Lonidovich Smirnov

Contact author: sbl@online.ru

That is for the sake of passive safety (and not for rest) that headrests appeared in the car. In the USA and Europe, with their kilometers-long rows of cars running at the same speed, a one-car-after-another collision is quite typical. One can easily imagine the consequences of a sudden throwing back of the head at the back hit. Throwing back of the head is certain spine fracture, and it is the headrest that saves the man’s life in this situation.

Companies known for their achievements in passive safety have been creating the entire back hit protection systems, which however are mainly used in expensive cars. For instance, the “active” headrest suggested by SAAB and NISSAN moves forward towards the head, while the Volvo whip protection system (WHIPS) moves the entire back of the front seat in a way to reduce the load on the whole spine.

Another example could be “Child’s air car seat with active headrest” (http://www.sciteclibrary.ru/rus/catalog/pages/6104.html).

The main drawback of the SAAB and NISSAN headrest is rigidity and complexity of its mechanical construction, which is installed on detached front seats, and envisages protection for the driver and front-seat passenger only, while the back-seat passengers remain unprotected. In addition, in case of the off-center back hit, with regard to the car long axis, the head could bend from the headrest.

The drawback of the child’s air car seat with active headrest is a cyclic principal of its operation, for after each usage the air is removed from there.

The purpose of the given invention is to create an “active” air headrest to ensure driver’s and passenger’s safety at the back hit of the car.

The set purpose is realized by means of air pockets in the headrest and seat connected with each other with pipe section props. Direct valves are built in the props, smaller check valves are built in the direct valves, ensuring the headrest readiness in the automatic mode. The headrest is equipped with self-opening side lobes to hold the head. The invention is described below on its performance examples with the help of the drawing.

Fig. 1 – driver’s seat in its usual position;

Fig. 2 – the same, at the back hit of the car;

Fig. 3a – the headrest in its usual position, top view;

Fig.3b – the same, in the expanded form after the back hit of the car.

The headrest operation is performed as follows.

At the back hit of the car the driver's or passenger's back strikes against the back of the seat 1, where the air pocket (not showed) is located, causing abrupt air pressure increase. This pressure jump makes direct valves, built in both props 2 of the headrest 3, open, Fig 1, 2. The air moves to the headrest, increasing it and lobes 4 in volume towards the head, Fig. 2 and 3b. This way whip fluctuation of the head is eliminated, and the risk of the thoracic and cervical part of spinal cord damage is therefore reduced. In addition, side lobes embrace the head from both sides, Fig. 3b, and do not let it bend from the headrest in case of the off-center or repeated hit. (The headrest dimensions increase depending upon the power of the back hit of the car). 

After the headrest has fulfilled its function its increased air pressure opens the check valves (smaller ones) built in the direct valves. Air from the headrest slowly moves to the air pocket of the seat back. The pressure in both air pockets levels making the headrest restore its initial shape.

Another advantage could be the fact that during a long trip, causing the headrest to be filled in with the air and inclining the seat back backwards the passenger could take a rest, for his head would be in a stationary position.

This construction will enable to equip not only the front seat but also the back ones with “active” air headrests, which significantly improve passive safety of the driver and passengers, including VIP passengers sitting at the back seat of the limousine.

Note.

The above mentioned ideas are drawn as an application to obtain the patent for invention of the Russian Federation. Publishing date: October 29, 2003

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