AU5195100A - Convertible vehicle seat - Google Patents

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Jakab Industries Pty. Ltd.

Actual Inventor: Geoffrey Alan Botfield e Address for Service: BALDWIN SHELSTON WATERS 60 MARGARET STREET SYDNEY NSW 2000 Invention Title: 'CONVERTIBLE VEHICLE SEAT' Details of Associated Provisional Application No. PQ2761 dated 12 Aug 1999 The following statement is a full description of this invention, including the best method of performing it known to me/us:- File: 29101AUP00 Documents received ss~ O FIELD OF THE INVENTION The present invention relates to multi-purpose vehicle seating and in particular to a vehicle seat that may be converted into a stretcher bed.

The present invention will be described with specific reference to ambulance interior fit-out design. However, it will be appreciated that seats according to the present invention are suitable for many other applications.

BACKGROUND OF THE INVENTION Modem ambulance design commonly provides for one stretcher only. The high levels of patient care that ambulance officers are required to provide will generally 10 preclude the officers from being able to fully attend to two patients simultaneously.

Despite this, there are occasions where it would be desirable to simultaneously transport two patients reclined on stretchers. Placing two stretchers in the ambulance o*o• takes up a lot of room that would normally be better used for medical equipment or to •give the ambulance officers more work space.

In an attempt to address this removable stretcher/chairs, such as that shown in AU45192/97 have been developed which can be configured as a conventional seat for the ambulance officer or a stretcher when transporting two patients. When configured as a conventional seat, this arrangement uses much less room than when configured as a stretcher. However, when configured as a stretcher, the aisle between the two stretchers is uncomfortably narrow for the ambulance officers and can hamper their activities. This is mostly because the wheel arch intrusion in the cabin prevents the stretcher/chair from being positioned flush against the side wall of the cabin. The stretcher/chair could extend over the wheel arch, in order to place it flush against the side wall of the ambulance, however, this would raise the patient support surface to an impractical height -3because of the bulky construction of the stretcher/chair mechanism. This mechanism is relatively bulky because of the high strength requirements that equipment such as this must have when used in ambulances.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

Accordingly, the present invention provides a convertible vehicle seat including: a seat base adapted to be mounted to the interior of a vehicle; S: a back rest rotatably mounted to the seat base for rotation between a generally 10 upright position in which the seat base and the back rest form a conventional seat, and a stretcher position in which the seat base and the back rest form a substantially horizontal surface for supporting a person in a prone position; *oo ~wherein, the seat base further includes at least one swing arm hinged to the seat base at one end and mounted to the back rest at the other end, at least two spaced locking formations fixed relative to the swing arm for rotation about the hinge axis, the locking formations being adapted for selective engagement with at least two complementary formations on the seat base such that, one of the locking formations engages one of the complementary formations when the seat back is in the generally upright position and the other locking formation engages the other complementary formation when the seat back is in the stretcher position.

Preferably, the seat base includes two swing arms, each hingedly mounted to respective opposing sides of the seat base. In a further preferred form, the swing arms are fixed to a hinge axle rotatably mounted on the seat base.

-4- In some embodiments of the invention, the locking formations are formed on a wedge shaped plate fixed to the hinge axle at its apex and extending downwardly therefrom. In these embodiments, the locking formations may be detents profiled into the edge of the plate remote from the apex. Furthermore, the complementary formations may be projections on a release lever hinged to the seat base, the release lever being manually operable to selectively engage the projections with the detents. In a further preferred form, the release lever is resiliently biased such that the projections are urged into engagement with the detents.

*In other preferred forms, the locking formations are formed on webs integrally extending from the swing arms. In a particularly preferred form, the webs are profiled to receive respective support abutments formed on the seat base to provide load bearing o. •points when the seat back is in the upright and stretcher positions. In this from, the locking formations and respective complementary formations align for mutual interengagement when in the upright or stretcher positions. In one embodiment, the oooo complementary formations are manually actuable for extending from the seat base into S" °engagement with the locking formations and manually actuable for retraction into the seat base to disengage the locking formations.

In a particularly preferred form, the seat base extends behind the back rest when in the generally upright position such that when the back rest is rotated into the stretcher position, the seat base and the back rest form a surface that supports the entire length of a person.

Preferably, the or each swing arm is hinged to the back rest such that the angle between the back rest and the or each swing arm is manually adjustable.

A convertible vehicle seat in accordance with the present invention provides a simple yet sturdy mechanism which allows the hinge axle to be relatively close to the top surface of the seat base so that the seat may be mounted over the wheel arch without raising the height of the patient support surface to an impractical level.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows an elevation of a convertible vehicle seat according to the present invention; 10 Figure 2 is a plan view of the seat shown in Figure 1; Figure 2 is a plan view of the seat shown in Figure 1; Figure 3 is a side elevation of the seat shown in Figure 1; Figure 4 is an elevation of the convertible vehicle seat in the stretcher configuration; Figure 5 is an elevation of the convertible vehicle seat in a semi-reclined configuration; Figure 6 is an elevation of the structural frame work of the seat shown in Figures 1 to Figure 7 is a side view of the frame work shown in Figure 6; Figure 8 is a plan view of the frame work shown in Figure 6; Figure 9 is a bottom view of the structural frame work shown in Figure 6; Figure 10 is a selected portion of the frame work shown adjacent the wheel arch intrusion in the rear cabin of a vehicle; Figure 11 shows a perspective of the framework of another form of the convertible vehicle seat according to the present invention; -6- Figure 12 is a side elevation of the framework shown in Figure 11; Figure 13 is a front elevation of the framework shown in Figure 11; Figure 14 is a plan view of the framework shown in Figure 11; and Figure 15 shows a side elevation of the framework shown in Figure 11 wherein the seat back has been rotated into the stretcher configuration.

Referring to Figures 1 to 10, the convertible vehicle seat has a seat base 1 and a back rest 2. The back rest is rotatably mounted to the seat base through a pair of swing arms 3 such that the back rest may be configured in a generally upright position to *a provide a conventional seat, or laid flat in a stretcher position to form a surface for 10 supporting a patient in a prone position.

The swing arms 3 are fixed to a hinge axle 4. A wedge shaped locking plate 5 is also fixed at its apex to the hinge axle 4. The peripheral edge opposite the apex includes detents 6 and 7 adapted to receive complementary locking projections 8 and 9. The o locking projections 8 and 9 are formed on the release lever 10 hinged to the seat base 1.

*a Manual operation of the lever 10 allows the user to selectively engage and disengage the projections 8 and 9 from the detents 6 and 7. To maintain the seat in the chosen configuration, spring 11 urges the projections 8 and 9 into engagement with the detents 6 and 7.

Previously known stretcher/seats, such as that taught by AU45192/97 have used a similar arrangement. The locking plate with two detents extended upwardly from the hinge axle to engage a single locking projection formed on the release lever.

Accordingly, the hinge axle is positioned a significant distance below the top surface of the seat base in order to allow the mechanism to work. If the hinge axle was simply brought closer to the top surface of the seat base, the locking plate would need to extend -7generally downwardly in order to engage the single locking formation. Because the single locking formation is used, the locking detents in the mounting plates need to be wider apart in order to allow the swing arms to rotate through the required arc between the upright position and stretcher position. Therefore, the wider locking plate would need to extend well into the cushion of the seat base to provide sufficient rotation for the swing arms. Obviously, a significant projection into the cushion of the seat base is a serious safety and comfort concern.

It will also be appreciated that with the provision of at least two locking -eta*: sees projections 8 and 9 on the release lever allows the locking detents 6 and 7 to be closer S* 10 together while still providing the necessary amount of rotation for the swing arms 3. As *o9999 •the locking detents 6 and 7 are closer together the mounting plate 5 correspondingly smaller and therefore does not significantly extend into the cushion of the seat base 1 •when in the upright configuration or stretcher configuration. Accordingly, the hinge axle may be positioned closely adjacent the cushion of the seat base 1. This permits the seat see 15 base to be mounted over the wheel arch intrusion 12 such that the support surface for the 9°4patient is at a practical height.

*9 In order to further vary the number of possible configurations of the seat, the back rest 2 is hinged to the swing arms 3 along axis 13. Adjustment knob 14 allows the angle between the swing arms 3 and the back rest 2 to be varied. As best shown in Figures 4 and 5, the back rest tilt adjustment allows the stretcher to vary between a semi-reclined position to a fully reclined position depending on the patient's requirements.

An extension 15 of the seat base 1 may be provided in order to lengthen the support surface provided in the stretcher configuration. The hollow cavity within the -8extension may be used for storage. For this purpose, it is a simple matter to adapt the cushion covering the extension to be the storage locker lid as well.

Figures 11 to 15 show another form of the convertible vehicle seat according to the present invention. Where possible, corresponding features have been referred to using the same item numbers shown in Figures 1 to 10. In this embodiment of the invention the wedge shaped locking plate has been substituted for the web portions 16 and 17 which are integrally formed with, and extend from, opposing edges of the swing arms 3.

The periphery of the webs 16 and 17 are profiled to respectively receive support abutments 18 and 19 which extend from the seat base 1 and act as load bearing points to support the seat back 2 when it is in the upright and stretcher positions.

In this embodiment the locking formations are provided by apertures 6 and 7.

These apertures align with complimentary formations provided by retractable pins 8 and 9 whenever the seat back 2 is in the upright or the stretcher configuration. Manual S rotation of the shaft 20 retracts or extends the pins 8 and 9 via the linkages 21. It would be usual to resiliently bias the pins 8 and 9 into the extended position to guard against unintentional disengagement from the apertures 6 or 7.

As with the embodiment shown in Figures 1 to 10, the swing arms 3 are hingedly connected to the seat back 2 via axel 22. This permits further angular adjustment between the seat base 1 and the seat back 2 when in either the upright or stretcher configurations.

It will be appreciated that providing locking formations that interengage with separate respective complementary formations in the seat base has allowed the overall width of the swing arms 3 to be reduced which in turn allows the axel 4 to be raised thus reducing the overall depth of the seat base 1.

-9- A convertible vehicle seat constructed with the present invention has the elegance of a simple and compact design without compromising the high strength requirements of this type of application. This permits the seat to be fixed in a position over the wheel arch intrusion to increase the useable space within the vehicle cabin.

The invention has been described herein by way of example only and many other variations and modifications would be readily apparent to ordinary workers in this field without departing from the spirit and scope of the broad inventive concept.

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Claims (4)

1. A convertible vehicle seat including: a seat base adapted to be mounted to the interior of a vehicle; a back rest rotatably mounted to the seat base for rotation between a generally upright position in which the seat base and the back rest form a conventional seat, and a stretcher position in which the seat base and the back rest form a substantially horizontal surface for supporting a person in a prone position; wherein, the seat base further includes at least one swing arm hinged to the seat base at one 10 end and mounted to the back rest at the other end, at least two spaced locking formations fixed relative to the swing arm for rotation about the hinge axis, the locking formations **being adapted for selective engagement with at least two complementary formations on the seat base such that, one of the locking formations engages one of the complementary formations when the seat back is in the generally upright position and the other locking formation engages the other complementary formation when the seat back is in the stretcher position.

2. A convertible vehicle seat according to claim 1, wherein the seat base includes two swing arms, each hingedly mounted to respective opposing sides of the seat base by a hinge axle extending between the swing arms.

3. A convertible vehicle seat according to claim 2, wherein the locking formations are formed on a wedge shaped plate fixed to the hinge axle at its apex and extending downwardly therefrom; the locking formations are detents profiled into the edge of the plate remote from the apex; and,

11- the complementary formations are projections on a release lever hinged to the seat base, the release lever being manually operable to selectively engage the projections with the detents. 4. A convertible vehicle seat according to claim 2 wherein the locking formations are formed on webs integrally extending from the swing arms, wherein the webs are profiled to receive respective support abutments formed on the seat base to provide load bearing points when the seat back is in the upright and stretcher positions. 5. A convertible vehicle seat according to claim 4 wherein the locking formations and respective complementary formations align for mutual interengagement when in the upright or stretcher positions. 6. A convertible vehicle seat according to claim 5 wherein the complementary formations are manually actuable for extending from the seat base into engagement with o .9 the locking formations and manually actuable for retraction into the seat base to 15 disengage the locking formations. *•ooo 7. A convertible vehicle seat substantially as herein described with reference to any one of the embodiments of the invention shown in the accompanying drawings. DATED this 11 th day of August, 2000 JAKAB INDUSTRIES PTY LTD Attorney: KENNETH W. BOLTON Registered Patent and Trade Mark Attorney of Australia of BALDWIN SHELSTON WATERS