WO1992005072A1

WO1992005072A1 - Aircraft seating

Info

Publication number: WO1992005072A1
Application number: PCT/GB1991/001586
Authority: WO
Inventors: Leslie James Simpson
Original assignee: Magerik Limited
Priority date: 1990-09-14
Filing date: 1991-09-16
Publication date: 1992-04-02
Also published as: GB9020137D0

Abstract

An aircraft seat provided with a rigid seat frame (1, 2, 3, 4) for securing to the floor of an aircraft cabin. The sitting position of the seat is provided with energy absorbing struts (9) disposed to either side of the seat and connected to one member (3) of the rigid frame lying along the front of the sitting position and at the other end to one end of a support arm (11) pivotally mounted to the rigid frame. The rigid frame is constructed such that there is an open space beneath each sitting position. The seat belts (10') anchoring the passenger in the seat are coupled to the energy absorbing struts (9) at the rear of the seat such that under predetermined dynamic loadings applied to the passenger as in an aircraft crash situation, the energy absorbing struts (9) yield and the seat back pivots forward to deposit the cushion support system of the seat into the space beneath the seat together with the passenger. Loading on the passenger is thereby much reduced and the resultant collapse of the seat within itself provides adequate space for evacuation of passengers during an emergency.

Description

AIRCRAFT SEATING

FIELD UF INVENTION

The present invention relates to aircraft seating.

BACKGROUND OF THE INVENTION

New regulations have recently been introduced requiring aircraft passenger seats to comply with specified dynamic strength tests on newly certified aircraft.

It is widely thought that these new regulations will extend to all passenger seats in the not too distant future.

These new rules require seats to be tested to Ibg and l g dynamic loads using dummies to measure passenger loading.

The seat design must not only meet new strength requirements but also not allow passenger loads to exceeα those stated in the regulations.

It is, therefore, αesirable to nave some form of energy absorbing system to minimise passenger loads.

Further additional regulations may require the resultant space between two rows of seats after testing to be a specified distance to facilitate easy egress from the seat in an emergency.

Therefore, it is desirable for the front part of the seat to move forward as little as possible. According to the present invention there is provided an aircraft seat comprising a rigid seat frame for securing to the floor of an aircraft, said seat frame supporting a seat sitting portion and a seat back portion, collapsible means for suspending the sitting portion to said rigid frame, energy absorbing strut means of said collapsible means, and means coupled to said collapsible means for securing a passenger in the seat whereby under predetermined conditions of dynamic loading applied to the passenger, said strut means yields to allow the suspended sitting portion of the seat to collapse with respect to the stationarily secured rigid seat frame.

By the above means as the energy absorbing strut means collapses the cushion support system of the seat drops into the support frame directing the passenger into a highly cushioned area beneath the seat thus reducing the loading on the passenger.

The resultant deformation also allows the seat to collapse x^ithin itself thus providing adequate space for evacuation during an emergency.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings wherein:

Fig 1 is a side view of a three seater collapsible aircraft seat in an upright position;

Fig 2(_.a) is a side view of the same seat as that shown in Fig 1 in a collapsed position and Fig 2(.b) a generalised plan view thereof; Fig 3 shows two embodiments of an energy absorbing strut for use with the seat structure shown in Figs I and 2; and

Fig 4 shows two forms of pivotal strut for use with the collapsable seat of Fig 1.

BEST MODES OF CARRYING OUT THE INVENTION

With reference to the drawings accompanying this disclosure, a seat design is illustrated which meets the criteria of the new regulations referred to above, the seating being provided with an energy absorbing system which allows only minimum forward movement of the front part of the seat when under dynamic stress. In this way the allowable space for egress of the passenger in emergency is maximised.

In Figs 1 and 2 an aircraft seat for accommodating three passengers is shown having a rigid triangular support structure created between vertical front and sloping rear legs 1 and 2 respectively and a front lateral tube 3. The rigid triangular structure is comϋleted bv means of horizontal struts 4.

The support structure is normally anchored to the floor of an aircraft cabin by means of front and rear leg fittings 5 and 6 engaging a cabin floor track

Mounted between the tube 3 along the front of the sitting positions and a parallel rear tube a at the rear of the sitting positions are energy absorbing struts 9, one on either side of a respective passenger seat, and generally in the plane thereof. Seat belt linkages 10 earring seat belts 10' for each sitting position are attached through machinings directly to the rear tube 8.

A strut 11 is pivotally mounted to a rigid arm 12 which extends normally from each sloping rear leg 2 along the support frame. Each pivotal strut 11 is connected to the rear tube 8 extending along the seat parallel to the front tube 3.

The seat cushion support system 12 is a flexible diaphragm connected between the front and rear tubes 3 and 8.

Further struts S are attached to the rear tube 8 to mount the seat backs, seat arms, and seat back table, as illustrated in Fig 1 and 2, the seat back being formed of upper and lower portions of differing rake with the arm rest mounted beneath the join between the seat back portions as shown.

Foam seat cushions 13 are assembled on the seat in the usual way.

In normal conditions the seat will remain stable and the passenger will remain secure in the seat by the seat belts 10'. When the load exerted through the passenger into the seat belts 10', in an aircraft crash situation for example, is above a predetermined level set by the loading characteristics of the struts 9, it causes the energy absorbing struts 9 to collapse with respect to the rigidly held tube 3. The struts 9 collapse towards tube 3 in a controlled manner by the rear tube 8 being allowed to travel forward by pivotal strut 11. As the energy absorbing struts 9 collapse the cushion support system 12 drops into the seat support structure and between legs 2 directing the passenger into a highly cushioned area and thus reducing the loading on the passenger.

The resultant deformation allows the seat to collapse within itself thus providing adequate space for evacuation during an emergency.

The energy absorbing struts 9 can be of a design typically shown in Fig 3. They may comprise, see Fig 3A, a telescopic arrangement wherein a push rod 14 acts against a wedge 15 inserted against the opening of a narrow passageway 16 with respect to the wedge 15 which prevents movement of the rod 14 under normal conditions, but when these are exceeded the wedge 15 is forced down the passageway 16 providing the controlled movement required. Alternatively, as shown in Fig 3B, the push rod 14 may act against an energy absorbing medium M such as gas or rubber, ana be provided with a crumple zone Z.

Further, in an alternative construction the struts II may have one or more pivot points 17 as shown in

Fig 4.

Claims

-o - CL IMS

1. An aircraft seat comprising a rigid seat frame for securing to the floor of an aircraft, said seat frame supporting a seat sitting portion and a seat back portion,^' collapsible means for suspending the sitting portion to said rigid frame, energy absorbing strut means of said collapsible means, and means coupled to said collapsible means for securing a passenger in the seat whereby under predetermined conditions of dynamic loading applied to the passenger, said strut means yields to allow the suspended sitting portion of the seat to collapse with respect to the stationarily secured rigid seat frame.

2. A seat as claimed in claim 1 wherein said rigid seat frame includes spaced sloping rigid first frame members mountable at one end in a stationary position to the floor of an aircraft cabin, and at the other end to a rigid second frame member disposed along the front of the sitting position of the seat, and a pivotal arm connected between each one of said first frame members and one end of a said strut means positioned to delimit the sides of the sitting position of the seat, said strut means being attached at its other end to said rigid second frame member of said seat frame.

3. A seat as claimed in claim 2 wherein each said strut means is connected between said rigid second frame member and a rigid rear frame member disposed along the rear of the sitting position of the seat, each said pivotal arm being connected to .said rigid

4. A seat as claimed in claim 3 wherein each said pivotal arm pivots about a support arm extending normal to the axis of that one of said first frame members to which it is attached.

5. A seat as claimed in any preceding claim wherein said means for securing a passenger in the seat is a passenger seat belt.