GB2240028A - Safety harness recoil attenuator - Google Patents

Abstract

The car seat belt is an elastically tensioned safety harness. The purpose of the "Recoil Attenuator" is to reduce the effects of elasticity. Films of simulated crash tests reveal that the torso of the test manikin starts to move backwards towards the seat, before the head ceases to move forwards from the seat. As a consequence, restraint loads acting on the torso are accentuated and extension of the head in particular away from the torso is accentuated when the torso is catapulted backwards. Logically the effect of whiplash is also accentuated when the torso is catapulted backwards and the head is tugged backwards. The extendable anchorage of the invention includes a 'shear pin' which may also be some other form of obstruction between fixed and extendable parts which is caused to fail when a 75 KG test manikin ceases to move forwards from sled anchors when crash tested in accord with British and European Standards. Ref BS 3254 ECE Regulation 16. Travel distance of the buckle is pre-set to match elongation of the webbing. The device comprises relatively moving plates, one have a slot through which a pin extending from the other plate passes. A friction washer controls the relative movement. By so doing, the effects of elasticity otherwise caused to react on the test manikin or human in the event of a road accident are attenuated. <IMAGE>

Description

THE CAR SEAT BELT RECOIL ATTENUATOR An extendable energy absorbing Link, for siting between seat belt Buckle and car chassis anchorage. Derived from the collapsible energy absorbing steering column, where impact loads are governed.

Much like the EASC, restraint loads and extension of body parts outboard of webbing contact area, are governed by the "Triggering Load" of the device.

Note: "Point of Equilibrium". When Dummy compressable and extendable mass ceases to move forward, from start to completion of webbing elongation.

Travel, from CLOSED to EXTENDED state, must equal webbing elongation, when crash tested in accord with related British and European Standards.

THE CAR SAFETY BELT RECOIL ATTENUATOR Eliminates the recoiling forces of safety webbing.

Reduces the injuries to the Chest and Abdomen.

Reduces stretch of the cervical column.

Reduces risk of Head or Legs striking the Steering Column.

Reduces risk of Skull or Brain injuries.

Reduces severity of whiplash injuries.

Reduces risk of broken Sternums, Ribs or Collar Bones.

Reduces risk of injuries to the Heart or Spine.

AND SO ON .......

EXPLANATION: All safety webbings in cars are coupled directly, or via, adjustable seats and retractors, to the car chassis.

In effect, all car anchorages remain rigid and immovable when the wearer of a safety belt is involved in a road accident.

The safety webbing becomes stretched much like a catapult, until the wearer ceases to move forward from the normally seated position.

Body parts beneath the webbing are compressed, that is, the Chest and Abdomen. But other parts such as the Head, Neck, Arms and Legs are extended.

As there is no yield at the points the webbing is anchored, the webbing is able to recoil to it's original shape, much like a catapult.

The results from simulated crash tests, using dummies, show that the Head is still moving forwards, when the Chest is starting to move backwards.

As a result, compression of the Chest is increased and extension of the Neck is also increased.

This is because the webbing is able to react totally against the rigid anchorage.

However, if webbing stretch is known and, if the load generated at completion of body movement forward is known and, if movement is caused to occur, between a first and a second anchor, which is equal to webbing stretch then the wearer is protected from the recoiling force of the webbing.

The wearer therefore remains in the forward attitude at the completion of arrest and, is not catapulted backwards.

Claims (1)

1. CLAIM

   An extendable energy absorbing link for siting between existing safety webbings and existing car chassis anchorages.

   An extendable device which will govern restraint loads acting on body parts beneath the webbing contact area.

   An extendable device which will also govern extension of the body parts outboard of the webbing contact area, such as, the Head, Arms and Legs.

   An extendable device which will start to function at loads generated, as recorded in simulated crash tests, conducted in accord with related British and European Standards.

   (Ref. BS 3254. ECE Reg 16/44).

   In effect, an extendable device which will reduce the magnitude and duration of "Impulses" recorded in simulated crash tests.