Wheelchair and occupant restraints

A harness for securing within a vehicle a wheelchair in which an occupant is secured by a lap-belt, the harness being attached not to the chair itself but to side buckles movable relative to the chair and/or occupant, the buckles being attached to the ends of the lap belt, to anchor straps tending to pull the buckles downwardly and rearwardly, and holding straps associated with the anchor straps and connected to forward parts of the buckles via parts of the chair frame so as to tension the buckles forwardly in response to decelerating forces applied direct to the chair.

This invention relates to the restraint of a wheelchair or like seat 
(hereinafter called a "chair") and its occupant in the event that the 
chair with its occupant are to be transported by means of a vehicle 
(including aircraft) or some either conveyance susceptible of very high, 
if transitory, accelerations (including decelerations) as in the case of 
an accident involving the vehicle. 
It is usually better that the person be removed from the chair and seated 
in one of the usual seats with a usual seat-belt, the chair being carried 
independently as baggage. 
However there are those whose disabilities render it undesirable for them 
to be removed from the chair for transport purposes. It is therefore often 
necessary to provide special means of restraint taking account not only of 
the inertia of the occupant himself, but also that of the chair which, 
unless suitably fastened to the vehicle, might aggravate injury to the 
occupant e.g. by pushing him too violently against the belt and, in an 
extreme case, increasing his effective weight by the weight of the chair. 
A typical system includes two front and two rear anchor points on the 
platform, to which points the chair is fastened, such as by straps e.g. 
webbing belts, with the seating reference plane at right angles to the 
platform and parallel to its direction of motion. Usually the straps are 
attached to the chair by clips. The anchor points are symmetrically 
disposed with respect to the seating reference plane and are transversely 
spaced by a distance substantially equal to the width of the chair. The 
front and rear anchor points may be longitudinally spaced by an adjustable 
distance, which may depend on the length and type of chair, and/or the 
lengths of the front and/or rear straps may be adjustable. 
In one known system, restraints are attached to the chair frame. Such a 
connexion is very liable to breakage and to expose the occupant and others 
in the vehicle to the risk of serious injury. 
An object of the invention is to provide a very safe and relatively simple 
system for restraining a wheelchair and its occupant on what may for 
convenience by described as a movable platform, which may be, for example, 
the floor of a vehicle. 
Another object is to provide a system which complies with a typically 
stringent governmental standard e.g. Australian Standard 2942-1987 
"Wheelchair Occupant Restraint Assemblies for Motor Vehicles". 
Other objects and advantages will become apparent hereinafter. 
Accordingly the present invention provides a safety harness for a 
wheelchair/occupant system being or to be transported on a movable 
platform liable to sudden stoppage or other potentially dangerous rearward 
impulse, the platform having associated therewith rear anchor means to 
which the harness is adapted to secure the system, said harness including 
a lap belt for the occupant and on each side of the chair a buckle 
providing a connexion movable relative to the system, said buckle being 
connected or connectible to the nearer end of the lap belt, an anchor 
strap tending to pull the buckle downwardly and rearwardly, and a holding 
strap associated with the anchor strap but connected or connectible to a 
forward part of the buckle via a chair part so that the buckle is pulled 
forwardly in response to decelerating forces applied direct to the chair 
via the holding strap. 
But in order that the invention ma be better understood reference will now 
be made to the accompanying drawings which are to be considered as part of 
this specification and read herewith. In the drawings:

Referring to the drawings in more detail, there is shown a wheelchair 6 
having a seat 7, armrests 8 and footrests 9 for an occupant (not shown). 
The chair and occupant comprise a system of two masses to be 
inter-harnessed, and also harnessed to platform 9 which may be the floor 
of a vehicle forwardly movable in the direction indicated by arrow 9A. 
Flush-fitted into platform or floor 9 are right and left front baseplate 
units 10, 11 and rear baseplate units 12, 13 adapted removably but 
securely to receive eyebolts such as 14 (FIG. 4) whereby the four harness 
components are securable to the floor 9 but can be manually disengaged, if 
necessary, when harness tension is suitably relieved. As best seen in FIG. 
3, the baseplate unit includes a top plate 15 underneath which is a 
receptacle 16 for the eyebolt via keyhole aperture 17. Eyebolt 14 is 
attached to the end of anchor strap 18. The baseplate units are bolted or 
otherwise firmly fastened to floor 9, the lastmentioned being suitably 
recessed as necessary in order to accommodate the unit, with plate 15 
flush with the floor. 
When the unit is not in use, aperture 17 may be automatically closed by a 
spring-loaded depressor plate (not shown) within receptacle 16. 
Therefore to attach the anchor it suffices to insert eyebolt 14 into the 
larger part of aperture 17 (by pushing it against the spring-pressure of 
the depressor plate when provided) and allowing tension in the associated 
anchor strap 18 to pull the bolt rearwardly (in the case of 10 and 11) or 
forwardly (in the case of 12,13) so that the bulbous part of the bolt is 
caught under the narrow part of the keyhole aperture. 
The harness includes a lap belt 19 for the occupant and on each side of the 
chair a buckle 20, 21 in the form of D-shaped clips, providing strap 
connections which are stable but "floating" i.e. movable relative to chair 
and/or occupant. As best shown in FIG. 5, each buckle is connected to the 
relevant (i.e. nearer) end of lap belt 19, and to the relevant anchor 
straps or strap assembly 18 both directly by connection strap 22 and also 
by holding strap 23 which is passed around chair post 24. 
Evidently, then, buckles 20, 21 are generally subject to three forces viz. 
the connection straps tending to pull the buckles downwardly and 
rearwardly, the holding straps forwardly and the lap belt upwardly and 
forwardly. It also appears that the retarding forces which are applied 
direct to the chair (by holding straps 23 passing around posts 24) also 
tend to pull the buckles forwardly. 
The anchor strap assemblies may including quick-release clips such as 25 of 
a kind known per se. 
Should the platform be suddenly decelerated, as in the case of a head-on 
collision, the inertia of the chair and its occupant may tend to pull 18 
and 19 into substantially collinear relationship, but subject to the 
forward pull of 23. 
Advantageously, the strap or belt connections are, wherever possible, 
effected by looping the strap around the relevant part and using e.g. a 
quick-release buckle or like attachment to secure the end of the strap 
back to the strap itself. 
This constitutes a much surer fastening than in many prior restraints, 
wherein very often strap ends are simply clipped to the frame, with great 
propensity to break or unfasten under the forces to which accidents can 
give rise. 
Preferably the harness straps or webbing are doubled where a strap is 
required to pass over a straight metal edge or such other formation as 
might sever the strap under large forces. 
If desired the rear and/or front straps may incorporate length-adjusting 
means 26 of a ratchet or other known type. It may suffice for one pair to 
be so adjustable. 
It will be evident from the foregoing that our restraint system is safe, 
simple and versatile. 
For the purpose of this specification terms such as "front", "rear", 
"upwardly", "downwardly", "forwardly", "rearwardly", "top", "right", 
"left", "under" and "underneath" refer to the invention in a position of 
use in a vehicle moving forwards along a horizontal road. They are not to 
be read as necessarily limiting.