AU785069B2 - Swivel seat for vehicle - Google Patents

Description

Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: SA St John Ambulance Service Inc Actual Inventor/s: Grad-Ziwvke4c Oe- CArYc-c Address for Service: MADDERNS, 1st Floor, 64 Hindmarsh Square, Adelaide, South Australia, Australia Invention title: SWIVEL SEAT FOR VEHICLE Details of Associated Provisional Application No: PR 3907 dated 22 March 2001.

The following statement is a full description of this invention, including the best method of performing it known to us.

*•oo Nam ofApiat AS on muac evcn AculIvno/: G-d* e. C_.c Adrs fo Sevc: C-MDEN,1tFlo,6 idas*qae Adlie Sot Autai, utai PatAU131 I This invention relates to rotatable seats for use in vehicles.

BACKGROUND

Motor vehicles are primarily designed to transport people and so for reasons of comfort and safety the vehicle passengers are seated. The orientation of the passenger in motor vehicles is fixed for safety sake so the passengers must face forward or rearward. In front and rear end collisions the vehicle seat will stabilise the seated passenger and absorb some of the tremendous forward and rearward forces placed upon the passenger in such circumstances. For most accidents a vehicle seat is still the primary device used to stabilise the movement of the passenger. However in more recent times a variety of passenger restraint devices such as seat belts and air bags are provided. In some countries such restraints are minimum regulatory requirements so that the vehicle manufacturer can obtain authority to manufacture 15 and offer for sale cars in that country. Vehicle design is improving and additional S safety elements including the way in which they are constructed to provide passenger safety cells, crumple zones, appropriate choice of interior trim materials, antilock braking etc are also becoming available.

S: 20 However, a consistent feature of and an assumption for vehicle designers is that vehicle seats are orientated for each passenger such that they face either forward .:oo•i or rearward. The orientation of seating is so important that it is decreed in various vehicle safety standards to be so and the orientation of seats are movable only backwards or forwards but certainly not rotatable.

There is however, a need at times to have a seat in a vehicle made so that it can temporarily orientate, typically to a sideways position. An example is the type of seat fitted either on the passenger or driver's side of the vehicle which allows a disabled or infirm person to more easily enter and exit a stationary vehicle.

The vehicle seat which provides this function is specially designed and must be approved by the road traffic authority for use in a vehicle and the only way in which it can be so approved is to ensure that it cannot be used in its sideways orientation while the vehicle is moving.

A further example of a situation in which a sideways facing seat is desirable occurs in mobile command vehicles, where radio equipment, video monitors and other display devices are arranged along the side walls of a rear-tray top mounted enclosure. Truck bodies and the like are often adapted to such uses and equipment operators are seated in front of the equipment so that they can conduct the many tasks required of them once the command vehicle has arrived and become stationary at the command post. This however means that the vehicle seats positioned and typically facing the side walls of the vehicle, are unuseable until the command vehicle is in its final stationary position that is, passengers cannot use those seats during transit of the vehicle to its destination or its return trip.

15 In yet a further example, there exists a need for a paramedic in the rear of an ambulance who is tending to a patient, to orientate themselves sideways of the direction of travel of the vehicle. Most importantly this orientation should be maintained during the whole duration of the transit of the patient to a place of care so that the ongoing needs of the patient can be met.

S Unfortunately the seats in the rear of an ambulance used by the paramedic must by law or regulation be orientated either forwards or backwards while the ambulance is in motion. As a consequence of this the paramedic will be required to rotate their upper torso towards the patient and bend and stretch to meet the patient's needs and so place unnecessary strain on their bodies and make it less safe for them while they are in transit tending to their patient.

Thus vehicle seats that can re-orientate sideways are of limited use if legally they can only be used while the ambulance is stationary. For occupational health and safety reasons such seats are not fitted in ambulances as it would be very likely that the paramedic would use the seat in its sideways orientation to properly tend to their patient but would then run the risk of serious injury if while doing so the vehicle was involved in an accident.

The aim of this invention is to provide a vehicle seat that will allow its occupant to re-orientate the seat during the motion of the vehicle and that it is designed such that it will re-orientate either forwards or rearwards in the event of an accident so as to minimise harm or injury to the passenger seated in that vehicle seat.

It is a further aim of the invention to provide a vehicle seat that still has a passenger restraint device such as for example a seat belt.

BRIEF DESCRIPTION OF THE INVENTION S"A seat for a vehicle consisting of a seat base and back rest forming a seat for a passenger, S: a swivel coupling between said seat base and said vehicle allowing the seat to orientate to one or more angles between the forward and backward facing positions, a swivel stop means for restraining the rotation of said seat base and backrest, said stop means comprising a shear element characterised in that when said seat is 20 occupied by a passenger having a predetermined weight said shear element will shear such that said swivel stop function of said stop means ceases and said seat base and back rest are unrestrained and able to swivel to a forward or backwards facing orientation.

In a further aspect of the invention a seat for a vehicle may also have one or more permanent stops to limit the maximum rotation of the swivel coupling to a portion of the 1800 angle of rotation between forward and backward facing orientations.

In a further aspect of the invention said swivel stop means has an adjustment means for removing said swivel stop means into or out of operation so as to facilitate while out of operation the rotation of said seat base and back rest relative to said vehicle wherein said adjustment means is operable by said seat occupying passenger.

In a further aspect of the invention said swivel coupling comprises at least two circular plates having a circular ball race and portions of both plates adjacent to one another so as to create frictional resistance to rotation relative to each other.

Specific embodiments of the invention will now be described in some further detail with reference to and as illustrated in the accompanying figures. These embodiments are illustrative, and not meant to be restrictive of the scope of the invention.

Suggestions and descriptions of other embodiments may be included within the scope of the invention but they may not be illustrated in the accompanying figures or alternatively features of the invention may be shown in the figures but not described in the specification.

BRIEF DESCRIPTION OF THE DRAWINGS r r o 20 Fig 1 depicts a rear perspective view of a vehicle seat; Fig 2 depicts a front perspective view of a vehicle seat; So Fig 3 depicts a closer view of the forward and rearward movement mechanism of a vehicle seat; Fig 4 depicts a pictorial representation of a swivel arrangement wherein the dotted lines represent the vehicle seat in a 600 orientation with respect to the forward facing axis; Fig 5 depicts a close up view of the swivel mechanism of a vehicle seat; Fig 6 depicts the stops located under and which depend from the base of the vehicle seat; Fig 7 depicts a pictorial representation of a shear pin located so as to maintain the vehicle seat in a forward facing orientation; and Fig 8 depicts a plan view of a swiveling vehicle seat located adjacent a supine patient.

DETAILED DESCRIPION OF AN EMBODIMENT OF THE INVENTION The vehicle seat depicted in Fig 1 could be used in any normal vehicle. In this example the vehicle seat 10 has a seat base 12 and a back rest 14. In a preferable embodiment the back rest is orthogonal to the seat base and no adjustment, in position, is possible between these two elements.

This is done for safety reasons and because there appears to be no need for such an adjustment arrangement when for example the seat is used only by a paramedic while they attend their patient in the rear of an ambulance in transit.

However, when the seat arrangement of the invention requires a back rest angle adjustment this can be provided. An adjustable arms rest 15 are depicted but these are merely optional.

A passenger restraint device, in this embodiment, an over the shoulder seat 20 belt assembly 16 is fitted to the vehicle seat 10. It is considered more appropriate to fix the seat belt to the seat than any part of the vehicle chassis as the belt will not oooll entangle with occupants of the vehicle and is more likely to conform to the wearer's torso in an appropriate manner. As the seat is designed to allow rotation, there would never exist an ideal chassis attachment location that would ensure proper restraint of the passenger in the vehicle seat. An anchorage post 17 is shown at the bottom region of the back rest 14. This is designed to have the required strength to allow for the safe anchorage of an infant and small child restraint harness. This allows for the use of "baby capsules" and "child restrain seats" to be legally attached to the seat. It is likely that when the seat is being used in this fashion it will be set either forward or rearward facing.

The vehicle seat also optionally has a head rest 18 which assists the restraint of the head of a seated occupant in the event of an unexpected occurrence.

The vehicle seat 10, as will be described in greater detail, is rotatable with respect to the support frame 20. The support frame is bolted and thereby fixed to the vehicle body.

The rotation of the vehicle seat is arranged to occur in predetermined discrete steps about the central axis and as is depicted in Fig 4, this embodiment shows that there are seven notches inclusive between the 00 and 600 orientations of the forward direction of the vehicle seat.

In Fig 2 like elements of Fig 1 are identified with the same numeral, as is the I case throughout this specification.

•To• More easily viewed in Fig 3 is the upper frame 20 and the seat base 12.

As is a feature of normal vehicle seats the seat is adjustable forwardly and rearwardly. In this embodiment this function is provided by runner frames 22 .20 attached to the seat base 12 that are shown to overlie and move longitudinally over runner guides 24 that are attached to the support frame a.

A handle 26 is of a size, shape and position so that it may be conveniently manipulated by the vehicle seat occupant while engaging or disengaging the runner frame and runner guides from one another to allow horizontal positioning of the vehicle seat. Stops (not shown) can be used to limit the extent of horizontal movement. It is possible to provide for side ways movement of the seat base 12 relative to the support frame 20 but this is not shown as the mechanism is known and would unnecessarily complicate the depiction of the preferred seat arrangement.

Fig 4 is a pictorial representation of some of the components of an adjustable swivel arrangement that incorporates a pin 28 for fixing the top plate 30 relative to the bottom plate 32.

There are a variety of ways in which top and bottom plates that swivel with respect to each other can be arranged to interact with one another so as to provide not only incremental adjustment but continuous adjustment about their common axis. The embodiment disclosed in this specification is but one way of providing incremental adjustment, and involves the use of spaced notches 34 located on the periphery of a bottom plate 32 and a pin 28 which descends from a housing or guide structure (not shown) located on the top plate 30. Various means to control the selective descent of the pin 28 are well within the skill of a trades person.

:•To allow relative rotation of the plates, the pin 28 is raised out of the notch it occupies to a level above the bottom plate and the top plate is then free to rotate/swivel about the common vertical axis 36 of the plates.

The mechanism for raising the pin is not illustrated but could comprise a lever mounted under the seat base, spring loaded to bias the lever and thus the pin in a 20 downwards direction. This bias is useful for two reasons, firstly it is an aid to locating the pin in the next notch as the top plate rotates across the bottom plate. The second reason is that the bias provides for positive location of the pin in a notch while the vehicle is moving.

Movement of the vehicle could otherwise without a pin bias means, knock the pin out of the notch and let the seat base rotate unrestrained or in an uncontrolled manner.

The shear pin lever's free end is located for ease of access and manipulation near by to the seat occupant's lower hand.

The notches in the bottom plate are arranged at the front of the seat but could also be positioned elsewhere about the periphery of the plate.

The dotted lines depicted in Fig 4 illustrate the rotated/swivelled location of the swivel seat, in this example, rotation at 600 from the forward facing direction.

As stated previously, it is potentially dangerous while the vehicle is moving for a seated occupant to occupy the seat while it is in a position rotated either away from the forward facing direction, or if achievable with a particular arrangement, the rearward facing direction.

Pin 28 is designed to shear under a predetermined condition such that in the event of that condition arising, the top and bottom plate of the swivel mechanism become disengaged and the vehicle seat returns in this embodiment to the forward facing direction.

o An example only, of a preferred condition, applies if the vehicle seat is occupied by a passenger weighing at least 38kg and that the vehicle and hence the vehicle seat are subjected to a deceleration of greater than 3 times gravitational S 20 acceleration When such a condition exists the pin 28 shears and the top 30 and bottom 32 plates rotate relative to one another in the manner described previously overcoming frictional resistance to rotation between the plates that exits.

The shear pin may, for example, be made of a selected alloy having a predictable shear strength laterally across the longitudinal axis of the pin.

The shear pin may also be made of steel and shaped so as to be frangible at a predetermined location along its longitudinal length upon the action of a greater than predetermined force above and below that frangible region. In a preferred embodiment the pin 28 is a 5mm mild steel rod having a 1.5mm radiused groove at its mid point at which point it is designed to shear under the appropriate conditions.

Alternatively, an hydrostatic device may be used to retain the pin into position but upon a suitable quantity of force in a predetermined direction the pin is permitted by the hydrostatic device to move out of a respective notch and remain clear of any intermediate notches until the forward facing position of the seat is achieved.

To control the limits of rotation of the seat, stops can be used, an example of which is depicted in Figs 5 and 6. Fig 5 shows a stop 38 depending from the base of the vehicle seat having a length sufficient to abut the slider 22 associated with the supporting frame 20 at a location rearwards with respect to the front or front facing vehicle seat. Stop 38 controls and limits the maximum rotation up to and including the forward facing orientation of the vehicle seat.

Fig 6 shows a second stop 40 that also depends from the underside of the S 15 vehicle seat and is of such a length that it will strike a forward portion of the slider 22 associated with the supporting frame The second stop 40 limits the maximum rotation up to and including the sideways orientation of the seat from the forward facing orientation of the vehicle 20 seat.

Thus, if the pin 28 shears, the rotation of the seat to a forward facing position 00 00* is limited by the first mentioned stop. While counter-rotating the vehicle seat, it can only be counter rotated to a degree limited by the second mentioned stop.

Fig 7 is an enlarged pictorial representation (also refer Fig 4) of the top and bottom plates 30 and 32 respectively.

Pin 28 is preferably a vertically orientated rod like element sized to fit into the circularly shaped notches 34.

In this representation guide slots 42 are preferably incorporated into the top plate 30 while fixed pins 44 are incorporated in the bottom plate 32. These slots and pins maintain the co-axial rotation of the plate as well as providing a limit to the amount of relative rotation that can be achieved between the plates. The slots may be positioned so as to exactly match the earlier mentioned stops 38 and 40 or replace the need for them.

As depicted in Fig 8, the rotatable seat 10 is shown located adjacent a patient.

The seats occupant 46 is facing slightly towards the patient thus necessitating an approximately 450 swivel of the seat.

The vertical axis of the centre of gravity of the occupant 46 is approximately at the location marked with a symbol if the occupant is properly seated and restrained in the seat 10. The vertical axis of the centre of gravity is therefore close to o:,o 15 but radially offset from the vertical axis of rotation of the swivel seat 52 as well as *@ooo° S, offset '48' from the longitudinal axis of the vehicle and offset '50' from the lateral axis of the vehicle both of those axes being through the centre of horizontal rotation 52 of S. the swivel seat 000S 20 With the centre of gravity offset in the manner described above in a forwardly moving vehicle, the forward momentum of the seat occupant in combination with ooooo their weight acting downwardly on the seat base, will if the vehicle decelerates, tend *O00 to rotate the seat and its occupant about its centre of horizontal rotation 52 such that the seat and occupant will face towards the front of the vehicle.

However, such rotation is resisted by the shear pin until the predetermined shear force of the pin is exceeded. The top plate tending towards the front of the vehicle will at that moment shear the pin 28. Once the shear pin is broken there is little restraint on the swivel action of the seat and it will rotate with its occupant to become forward facing.

This would also be the result if the swivel seat was arranged such that it was possible to rotate on the opposite side to that shown in Fig 8.

Furthermore if the seat occupant happened to be leaning over towards the patient at the time of a collision, the result would also be the same as described above. This would occur since the vertical axis of the centre of gravity of the passenger is a greater radial distance from the vertical axis 52 of rotation of the swivel seat as would the offsets (48 and 50) be greater than those described above.

Thus the moment of inertia of the passenger around the centre of horizontal rotation 52 is greater and thus will shear the pin earlier than in the previously described example resulting in the reorientation of the seat and its occupant forwardly in the event of an appropriate condition typically experienced in a accident.

It will be appreciated by those skilled in the art, that the invention is not 15 restricted in its use to the particular application described. Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein.

It will be appreciated that the various modifications can be made without departing from the principles of the invention. Therefore, the invention should be S understood to include all such modifications within its scope.

*e

Claims (15)

1. A seat for a vehicle consisting of a seat base and back rest forming a seat for a passenger of said vehicle, a coupling between said seat base and said vehicle allowing the seat base to swivel about a vertical axis so as to move to one or more positions that lie between a forward or backward facing position relative to said vehicle, a stop means for restraining the rotation of said seat relative to said vehicle, and further comprising a device to disable said stop means in predetermined conditions so that said seat is unrestrained and able to swivel to a forward or backward facing position relative to said vehicle.

2. A seat for a vehicle according to claim 1 further comprising one or more permanent stops to limit the rotation of said coupling to a portion of the 180' angle of rotation between a forward and backward facing position relative to said vehicle.

3. A seat for a vehicle according to claim 1 further comprising means to adjust 15 said seat sideways relative to said vehicle. oooo S4. A seat for a vehicle according to claim 1 further comprising an adjustment means for temporarily disabling said stop means so as to allow the rotation of said S seat relative to said vehicle. A seat for a vehicle according to claim 4 wherein said adjustment means is adapted to be operable by the occupant of said seat.

6. A seat for a vehicle according to claim 5 wherein said adjustment means comprises a lever associated with said stop means.

7. A seat for a vehicle according to claim I wherein said coupling comprises two plates one fixed relative to said seat base and the other fixed relative to said vehicle, said coupling having a ball race between said plates.

8. A seat for a vehicle according to claim 1 wherein said device is a shear element characterised in that said shear element will shear in said predetermined conditions.

9. A seat for a vehicle according to claim 8 wherein said shear element is a frangible pin.

10. A seat for a vehicle according to claim 7 wherein said device is a shear element located relative to said plates so that when said element shears, rotation of said seat relative to said vehicle is unrestrained.

11. A seat for a vehicle according to claim 10 wherein said shear element is a frangible pin. 10 12. A seat for a vehicle according to claim 11 wherein said plates have a plurality of apertures, and said frangible pin is shaped so as to enter one of said apertures in S each plate, so as to prevent relative movement of said plates.

13. A seat for a vehicle according to claim 12 further comprising a lever attached to said pin operable to remove said pin from an aperture in at least one of said plates 15 so as to allow relative movement between said plates.

14. A seat for a vehicle according to claim 13 wherein said lever is adapted to be S• operable by the occupant of said seat. A seat for a vehicle according to claim 1 wherein said device is hydrostatically operable and operates to permit rotation of said seat relative to said vehicle.

16. A seat for a vehicle according to claim 7 wherein said device is hydrostatically operable and located relative to said plates and operates to permit rotation of said seat relative to said vehicle.

17. A seat for a vehicle according to claim 16 wherein said plates have a plurality of apertures and said hydrostatically operable device operates a pin shaped so as to enter one of said apertures in each plate so as to prevent relative movement of said 14 plates.

18. A seat for a vehicle according to claim 17 further comprising a lever attached to said hydrostatically operable device to remove said pin from an aperture in at least one of said plates so as to temporarily allow relative movement between said plates.

19. A seat for a vehicle according to claim 18 wherein said lever is adapted to be operable by the occupant of said seat. Dated this 2 5 h day of July 2006. J* OJ10 SA AMBULANCE SERVICE INCORPORATED By its Patent Attorneys MADDERNS S