Vehicle driver and passenger doors conventionally take a number of forms.

Most vehicles are equipped with conventionally hinged doors which are hinged to the vehicle at the front edge of the door and pivot towards the front of the vehicle. Some vehicles are provided with so-called suicide doors where the doors are hinged to the vehicle at the rear edge of the door and pivot towards the rear of the vehicle.

Still others are provided with doors which are not hinged to the body of the vehicle but instead are mounted on slide rails and which slide towards the rear of the vehicle to open.

Embodiments of the present invention provide an alternative form of vehicle door.

According to one aspect of the present invention, therefore, there is provided a mechanism for a door comprising a hinge arrangement connected to the door and arranged to permit the door to pivot or rotate between a first position and a second position, the hinge arrangement being adapted to cause pivoting or rotational movement of the door about a first pivot point through a first predetermined angle of rotation and subsequent movement of the door about a second pivot point through a second predetermined angle, the first and second pivot points being offset from one another.

The first movement of the door may be in an arc having a first radius of rotation. The second movement of the door may be in an arc having a second radius of rotation. The first radius of rotation may be greater than the second radius of rotation.

According to a second aspect of the invention there is provided a hinge device having an attachment member for an opening leaf, a mounting member for said hinge device, axis means defining an axis of rotation of the attachment member and first drive means for urging the axis of rotation to move relative to said mounting member.

The hinge device may further comprise an elongate member and a securing device for rotatably securing the elongate member to the mounting member at a first location of said elongate member, said elongate member affording the axis means at a location spaced from the first location.

The first drive means may be arranged to act between the mounting member and the elongate member to urge the elongate member in rotation about the first location.

The first drive means may comprise a first actuator device secured to the mounting member and to the elongate member at a location spaced from the first location.

The elongate member may be constrained to rotate about an axis substantially parallel to said axis of rotation.

The axis means may comprise a first pivot and the securing device comprise a second pivot, the first and second pivots being mounted to have substantially parallel axes.

The hinge device may further comprise a second drive means for urging the attachment member to rotate about said axis of rotation The second drive means may be arranged to act between the elongate member and the attachment member The second drive means may comprise a second actuator device secured to the attachment member and to the elongate member at a location spaced from the first location.

According to a further aspect of the invention there is provided a vehicle comprising at least one hinge device according to the second aspect of the invention, the or each hinge device supporting a respective vehicle door.

According to a yet further aspect of the invention there is provided a method of opening a door leaf mounted to and engaged with a structure, the method comprising urging a first hinge axis outwardly from the structure whereby the door moves out of engagement with the structure and then driving the door in rotation about the said hinge axis.

The urging step may comprise causing a member supporting the hinge axis to rotate relative to the structure.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective cut-away view of a mechanism embodying to the invention; Figures 2A-2E are partial schematic views of the mechanism of Figure 1 showing different stages in operation; Figure 3 is a view from above of a pair of vehicle door in a closed position showing part of the hinge and operating mechanism; Figure 4 is a view similar to Figure 3 with the vehicle doors in a partially open position; and Figure 5 is a view similar to Figure 3 with the vehicle doors of Figure 2 in a fully open position.

In the various figures, like reference signs refer to like parts.

Referring to Figure 1, a mechanism embodying the invention is shown generally at 10. The embodiment is a hinge mechanism for a vehicle door.

Referring also to Figure 2B, the mechanism 10 comprises a right angled hinge member 12 which is fixedly mounted to a door (not shown) at one end 13 thereof and pivotably connected to an arm member 14 at the other end 15 thereof for pivoting movement about an axis defined by a first pivot pin 16.

The arm member 14 has a first free end which defines a location for the first pivot pin 16, and a second end where the arm member 22 is mounted to a support member 20 via a second pivot pin 22. The support member forms part of the structure of a vehicle.

Rotational or pivoting movement of the hinge member 12, and hence the door, relative to the arm member 14 is caused by a first hydraulic or pneumatic actuator 18 having an arm 18a and a cylinder 18b.

The arm 18a of the first actuator 18 is connected to the hinge member 12 at a bearing block 17 spaced along the hinge member 12 from the pivot pin 16. The cylinder 18b of the first actuator 18 is pivotably connected to the arm member 14 at or near its second end, i. e. at or close to the second pivot pin 22. The first actuator 18 extends generally parallel to the arm member 14 although it is free to rotate relative to the arm member 14 according to the position of the hinge member 12. The first actuator 18 has a non-extended position-see Figure 2B, in which the door is closed or almost closed and an extended position-see Figure 2E in which the door is fully open. As the first actuator 18 extends, the resulting rotation of the hinge member 12 causes the first actuator 18 to rotate slightly relative to the arm 14.

As previously mentioned, the arm 14 is itself pivotally mounted on a support member 20 for rotation about the second pivot pin 22. Rotation of the arm 14 relative to the support member is caused by a second actuator 24, having an arm 24a and a cylinder 24b.

Referring to Figure 2A, the cylinder 24b of the second actuator 24 is pivotally connected at one end thereof to the support member 20 via a third pivot pin 26, this latter being offset again from the second pivot pin 22. The arm 24a of the second actuator 24 is pivotally connected to the arm member 14 at or near its first end via a bearing block 28.

Referring to Figures 2A-2E, the action of the actuators will now be described.

In Figure 2A which shows the second actuator 24 acting on the arm member 14, the second actuator 24 is in its retracted state. Extension of the first actuator in the direction"X"causes the arm member 14 to rotate anticlockwise in the direction"Y"as shown to the position shown in Figure 2C. Figure 2B shows the first actuator 18 in its retracted state and the arm member 14 in a disposition corresponding to that of Figure 2A. Figure 2D shows the first actuator 18 in its retracted state and the arm member 14 in a disposition corresponding to that of Figure 2C Once the arm member 14 is in the outwardly deployed state of Figure 2C, extension of the first actuator 18 produces the situation shown in Figure 2E.

Operation of the mechanism 10 will now be described with reference to Figures 3 to 5. Starting with Figure 3, it will be seen that the vehicle has a forward door 11 which is hinged at its front edge region 31 so that upon opening (see Figures 4 and 5) the rear edge region 32 moves wide open. However it will be seen from Figures 4 and 5 firstly that the rearward door 51 is hinged at its rear edge region 52, and secondly that the doors each move outwardly from the car somewhat before a normal rotation occurs. The outward movement, as will be later described herein, is in fact not a translation as such but is instead a rotation about a radius longer than the door. To rotate the door 11 from the first, closed position shown in Figures 1 and 3 to the second, open position shown in Figure 5, the user operates a switch, button or the like (not shown).

Actuating the switch activates a control unit (not shown) connected to the first 18 and second 24 actuators.

After actuation of the switch, the control unit firstly activates the second actuator 24 which moves from a first, non-extended position thereof to a

second, extended position. The extension of the second actuator 24 causes the arm member 14 to pivot through a predetermined angle about the second pivot pin 22. This first pivoting movement, which may be through a relatively small angle such as between 2° and 20°, causes the hinge member 12, and hence the door 11, to pivot also.

The door 11 thus pivots in an arc of a circle having its centre at the second pivot pin 22. This initial pivoting movement of the door effectively moves the door away from the body of the vehicle. The visual effect of this is that the door moves outwardly from the vehicle and slightly rotates. The relatively large radius of rotation created by the length of the arm member 14 means that the actual angle of rotation of the door during the initial pivoting movement is small. This is also constrained by the offset positions of the second and third pivot pins 22,26.

Following the first pivoting movement, the control unit then activates the first actuator 18 which moves from a first, non-extended position thereof to a second, extended position. The extension of the first actuator 18 causes the hinge member 12 to pivot about the first pivot pin 16 relative to the arm member 14 and the support member 20.

The door 11 thus pivots in an arc of a circle having its centre at the first pivot pin 16. The radius of rotation of this second pivoting movement is smaller than that of the first pivoting movement by an amount equal to the length of the arm 14. The effect of this is that the door 11 rotates through a much greater angle, in the manner of a conventional hinged door.

It can be seen that the mechanism of the invention, which can be used for vehicle doors or any other type of hinged door, causes the door to rotate in two

stages. A first rotation, having a first relatively large radius of rotation, is effected, causing the door to move outward from the vehicle and to rotate slightly. Following this, a second rotation, having a second, smaller radius of rotation is effected causing the door to rotate in the manner of a conventional hinged door.

An embodiment of the invention has now been described. The invention is not however to be limited to details of the embodiment but instead extends to the full scope of the appended claims.