Patent Publication Number: US-2021172226-A1

Title: Hatch operating mechanism

Description:
TECHNICAL FIELD 
     The invention relates to a hatch operating mechanism arranged to control opening and closing movements of a hatch covering an opening in a vehicle. The invention further relates to a hatch comprising such a hatch operating mechanism and a vehicle comprising a hatch according to the invention. 
     The invention is primarily intended for buses but can be applied in heavy-duty vehicles, such as trucks and construction equipment. Although the invention will be described with respect to a bus, the invention is not restricted to this particular vehicle, but may also be used in other vehicles such as wheel loaders, articulated haulers and commercial vehicles in general. 
     BACKGROUND 
     Vehicles, in particular relatively large vehicles such as buses, can be provided with a number of external hatches. Such hatches can be opened to allow access to luggage and general storage compartments which are accessed from the outside of the vehicle. A classical arrangement of a vehicle hatch is shown in KR2014076114A, in which the vehicle door is pivotally attached to the side of the vehicle. In order to open a vehicle hatch of this type, it must be lifted and pivoted upwards, which can be quite laborious and also requires a large amount of space as the hatch is swung outwards and upwards to its open position. 
     An alternative arrangement is shown in DE-GM 1884186, wherein a moving mechanism for a lateral hatch of a bus. The mechanism includes a linkage system attached to the hatch which linkage system is acted on by an actuator for pivoting the hatch away from the luggage compartment opening and into a position parallel with the side of the vehicle. The space required for the linkage mechanism and the actuator in addition to the space required for displacement of the hatch is not inconsiderable and reduces the available space for luggage. 
     The invention provides an improved hatch operating mechanism for this type of hatch in the external surface of a vehicle and aims to solve the above-mentioned problems. 
     SUMMARY 
     An object of the invention is to provide a hatch operating mechanism, which mechanism solves the above-mentioned problems. 
     The object is achieved by a hatch operating mechanism according to claim  1 . 
     According to one aspect of the invention, the object is achieved by means of a hatch operating mechanism arranged to control the opening and closing movements of a hatch covering an opening in a vehicle. The opening is preferably, but not necessarily located in an external surface of the vehicle body. The hatch operating mechanism comprises a first and a second arm, wherein each arm comprises a first end rotatably attached to the vehicle and a second end rotatably attached onto the hatch via a connecting element, and a main extension connecting the first and second ends. The first and second ends of the respective first and second arm extend in opposite directions, giving the arms a general Z-shape. The hatch operating mechanism further comprises a first and a second connecting element, wherein opposite ends of each connecting element are arranged to extend between and cooperate with a pair of spaced apart parallel guide means fixed to the hatch. According to one example, the parallel guide means are preferably, but not necessarily, horizontal and are located along an internal surface of the hatch, facing the interior of the covered compartment. The second ends of the first and second arms are rotatably attached to the first and the second connecting element, respectively, at a suitable position between the opposite ends thereof. 
     The respective pair of arms and connecting elements is located in mirrored positions relative to a plane of symmetry located at right angles to the main extension of the guide means. The first ends of each first and second arm can comprise integral first shafts arranged in a common plane wherein the first shafts have axes arranged at equal and opposite angles relative the plane of symmetry. According to one example, the common plane can be located at right angles to the plane of symmetry and orthogonal to a plane extending through both the parallel guide means, which plane can coincide with the general plane of the hatch. The second end of each arm can comprise an integral second shaft arranged to be rotatable relative to its connecting element about its own axis and which second shaft has an axis arranged parallel to its corresponding first shaft on the respective arm. Hence, the second shaft has an axis arranged at the same angle to the plane of symmetry as the axis of the first shaft. In this context, the plane of symmetry is located at the mid-point between the first ends of each first arm. The point of intersection of the axes for the first ends or their integral shafts will be located in the plane of symmetry. In the examples below the plane of symmetry is shown at the centre of the corresponding hatch. However, within the scope of the invention it is possible to place the plane of symmetry offset from the centre of the hatch. 
     In operation, simultaneous rotation of the first and second arms about their first ends or shafts in predetermined, opposite directions relative to each other is arranged to cause a primary displacement of the first and second connecting elements along the guide means from a first position to a second position. In the second position, the arms have been rotated half way through an arc delimited by the initial position and the final position of the respective arm during the opening of the hatch. The arc encompassing the initial position and the final position is less than 180°. Continued rotation of the first and second arms about their first ends or shafts causes a subsequent secondary displacement of the connecting elements back to the first position, whereby the hatch has been moved from a closed position to an open position. In this way, the connecting elements are arranged to execute a reciprocating movement along the guide means during the rotation of the first and second arms. In order to close the hatch, the first and the second arm are simultaneous rotated in their reverse directions from the final position to the initial position. During the movement of the hatch between the closed and open positions, the hatch is maintained substantially parallel to the side of the vehicle. The hatch itself will perform a swinging movement away from the vehicle. The swinging movement will have a relatively small curvature during the initial opening in order to displace the hatch away from the opening. The curvature will be relatively large as the hatch approaches its fully open position, in order to maintain the hatch adjacent the vehicle side and reduce the space required for opening the hatch. The shape of this variable curvature is determined by the angle of the first shafts and first ends of the respective first arms relative to the plane of symmetry. 
     By the provision of a hatch operating mechanism which comprises the above mentioned component parts, the invention achieves the advantage of providing a mechanism that allows the hatch to be displaced in parallel with the side of the vehicle during opening and closing. In order to allow parallel, or sideways, displacement of the hatch, the hatch operating mechanism is operated over an initial, predetermined distance sufficient to move the hatch away from the side of the vehicle and clear of the opening. By releasing a mechanical locking device and/or by operating a drive unit drivingly connected between the connecting element and the guide means, the hatch can be opened sideways in either direction over a limited distance, until one of the connecting elements reaches the end of the guide means. 
     The hatch operating mechanism according to the invention can be operated manually or be power assisted by means of one or more drive units. A power assisted hatch operating mechanism can comprise at least one primary drive unit arranged to be drivingly connected to the first shafts at the first ends of the respective first and second arms, wherein the at least one primary drive unit is arranged to drive the first shafts in opposite directions relative to each other. 
     A hatch operating mechanism according to a first example comprises a primary drive unit connected to the vehicle adjacent a central portion of the opening in the side of the vehicle. The drive unit is attached to the vehicle on or near a surface delimiting the compartment adjacent the internal surface of the hatch when the hatch is in its closed position. The drive unit extends a predetermined distance into the compartment, allowing the common plane of the axes of the first shafts of the first and second arms to extend out of the opening parallel to an adjacent edge of the opening. The primary drive unit is drivingly connected to both the first shafts of each first end via a suitable transmission mechanism for simultaneous rotation of the arms in predetermined opposite directions. Alternatively, each first shaft can be driven by a separate motor, wherein both motors are arranged adjacent a central portion of the opening in the side of the vehicle. In a preferred example, the first shaft of each arm is arranged at a predetermined angle α relative to the plane of symmetry. In this case, the angles are arranged to diverge towards the interior of the vehicle. The angle can be selected within the range 0°&lt;α&lt;75°, depending on the location of the hatch on the vehicle, the type, size and thickness of the hatch and the shape of the opening to be covered. 
     At relatively low angles, e.g. in the range 1°-5° the axes of the first shafts of the first and second arms will be near parallel. In such cases, rotation of the first and second arms will cause a relatively small outwards displacement before the hatch is lifted upwards parallel to the wall surrounding the opening. This can be achieved if an inner surface of the hatch is located flush with the outer wall surrounding the opening when the hatch is in its closed position. The inner surface of the hatch has an outer edge in contact with an outer surface of the wall surrounding the opening. The inner surface can extend inwards from the outer edge to at least partially overlap the adjacent outer wall surface. 
     The outwards displacement will then be sufficient to move the hatch out of contact with the outer wall. The first ends of the first and second arms will extend out of the opening, from the drive motor or motors and into the interior of the hatch. The first and second arms, the connecting elements and other components making up the mechanism can be located within an interior space between the main inner and outer surfaces of the hatch. If a seal is required, then a solid seal comprising a natural or synthetic rubber material or a suitable elastic non-compressible polymer material can be used. If the angle is increased, then the initial outward displacement will also increase, allowing a compressible or deformable seal to be used. 
     As the angles are increased, the initial outward displacement of the hatch will increase correspondingly. Depending on the thickness of the hatch and the shape of the opening, a comparatively larger angle can achieve an initial outward displacement allowing the outer surface of the hatch to be located flush with the outer wall surrounding the opening in its closed position. In its closed position, the hatch would then be arranged in a recess along the edge of the opening. A suitable seal can be arranged along the side edge of the hatch, along the outer edge of the inner surface of the hatch, or in the recess surrounding the opening. 
     At relatively high angles, e.g. up to 75°, the outward displacement of the hatch will increase correspondingly. Although the hatch will remain parallel to the wall containing the compartment, the distance between the hatch and the outer surface of the wall during opening will increase with increasing angles. Hence, the upper limit for the angle can be restricted by a maximum desired value for the distance between the hatch and the wall during opening, as this distance determines the allowable spacing between adjacent parked vehicles. 
     A hatch provided with a hatch operating mechanism comprising a single, centrally placed primary drive unit can be arranged to be opened by means of the primary drive unit and the first and second arms only. According to a first alternative example, the hatch operating mechanism is provided with a stabilizing arrangement arranged to prevent sideways displacement of the hatch during the opening and closing operation. The stabilizing device comprises a central sliding member arranged to move between and parallel with the connecting elements adjacent a pair of first ends of the connecting elements during actuation of the hatch. A pair of struts are arranged to extend from pivots on the central sliding member adjacent and equidistant from the first ends of the connecting elements to pivots on a respective second end of each connecting element. The central sliding member is arranged to cooperate with a central guide having an axis intersecting a central position of the guide means in the plane of symmetry through the hatch. During operation of the hatch, the reciprocating displacement of the connecting elements causes the struts to act on the central sliding member, which will perform a corresponding reciprocating movement along the central guide. As the central guide is fixed to the hatch the central sliding member can only move along the axis of the central guide. This prevents the hatch in this first alternative example from moving in a sideways direction while opening or closing the hatch. 
     A hatch provided with a hatch operating mechanism comprising a single, centrally placed primary drive unit can also be arranged to be opened sideways, at substantially 90° to the main direction of the movement caused by actuation of the first and the second arm. Once the hatch operating mechanism has been operated over an initial, predetermined distance sufficient to move the hatch away from the side of the vehicle and clear of the opening, the primary drive unit can be stopped. In this intermediate position the hatch can be arranged to be displaced sideways, either manually or by means of at least one secondary drive unit. Depending on the design of the hatch operating mechanism a mechanical locking device, that prevents sideways displacement of the hatch during operation of the first and the second arm, can be released to enable sideways movement. The mechanical locking device can be position dependent and/or be operated manually or by any suitable drive means in order to release it to allow sideways displacement of the hatch in a desired direction. 
     Subsequent manual operation or operation of the secondary drive unit causes a sideways displacement of the hatch parallel to the guide means, at right angles to the initial displacement caused by the primary drive unit. This allows the hatch to be opened sideways in either direction over a limited distance, until one connecting element reaches the end of the guide means. An advantage with this arrangement is that access can be provided to a limited portion of the storage or luggage compartment. This can be useful in cases when it is desired to provide access to a selected portion of the storage compartment, e.g. for security reasons or for weather related reasons, such as a heavy downpour of rain. 
     As described above, in connection with the first alternative example, the hatch operating mechanism is provided with a stabilizing arrangement arranged to prevent sideways displacement of the hatch during the opening and closing operation. This is also the case for hatches arranged to be opened sideways. 
     According to a second alternative example, a mechanical locking device is arranged to be position dependent in order to release it to allow sideways displacement of the hatch in a desired direction. The hatch operating mechanism according to the second alternative example is provided with a stabilizing device that also acts as a mechanical locking device. According to this example, the stabilizing device comprises a central rod arranged between and parallel with the connecting elements. A pair of struts are arranged to extend from pivots at a first end of the central rod adjacent one end of the connecting elements to a respective pivot at the opposite end of each connecting element adjacent the second end of the central rod. The central rod can be arranged to cooperate with guides intersecting a central position of each guide means. The central rod and the guides are preferably located in the plane of symmetry through the hatch. Each guide means is interrupted by a gap at the point of intersection, in order to allow the central rod to pass through the guides located in the gaps between the interrupted guide means. During operation, a first end of the central rod is arranged to cooperate with a first guide when the hatch is in its closed position and in its fully open position. A second end of the central rod is arranged to cooperate with a second guide while the hatch is moving between its closed position and its fully open position. 
     The central rod can further be arranged to be located in an intermediate position between and out of contact with both the first and the second guide. This position is reached when the hatch operating mechanism has been operated over an initial, predetermined distance sufficient to move the hatch clear of the opening. The hatch operating mechanism can be stopped in this intermediate position, in order to allow displacement of the hatch parallel to the guide means. The parallel first and second means will then allow the hatch to slide sideways relative to the connecting elements held in position by the primary drive unit and the first and the second arm. This enables the hatch to be opened sideways without being obstructed by the stabilizing device. In this way the stabilizing device in this example can be used as a position dependent mechanical locking device. The hatch can be opened sideways in either direction over a limited distance, until one connecting element reaches the end of the guide means. 
     Subsequently, the hatch is returned to the intermediate position, wherein the central rod is indexed with both the first and the second guide. The primary drive unit can then be operated to actuate the first and the second arm in order to displace the hatch towards its open or closed position. 
     The hatch operating mechanism in this example can be provided with an optional secondary drive unit. The secondary drive unit can be arranged on at least one end of a connecting element and is drivingly connected to an adjacent guide means. The sideways displacement of the hatch can then be controlled by switches adjacent the hatch, by means of a hand held remote, or from a remote location within the vehicle. 
     According to a third alternative example, a mechanical locking device is arranged to be operated manually or by any suitable drive means in order to release it to allow sideways displacement of the hatch in a desired direction. The hatch operating mechanism according to the third alternative example is provided with a stabilizing device comprising a mechanical locking device mounted on the hatch. The stabilizing device comprises a central sliding member arranged to move between and parallel with the connecting elements adjacent a pair of first ends of the connecting elements during actuation of the hatch. A pair of struts are arranged to extend from a common pivot on the central sliding member adjacent and equidistant from a pair of first ends of the connecting elements to pivots on a respective second end of each connecting element. The central sliding member is arranged to cooperate with a central guide in the locking means, which is mounted to the hatch. The central guide is initially located in a first position with an axis intersecting a central position of the first and second guide means in the plane of symmetry through the hatch. During operation of the hatch using the primary drive unit, the reciprocating displacement of the connecting elements causes the struts to act on the central sliding member, which will perform a corresponding reciprocating movement along the central guide at right angles to the first and second guide means. As the locking means is mounted on the hatch the central sliding member can only move along the axis of the central guide while the hatch is displaced by the first arms. This prevents the hatch in this example from moving in a sideways direction while opening or closing the hatch. 
     The central guide is rotatable 90° from the first position to a second position about an axis at right angles to the plane of the hatch, in order to release the mechanical locking device. In the second position the axis of the central guide is parallel to the first and second guide means attached to the hatch. Rotation of the central guide is possible when the common pivot of the central sliding member is located coinciding with the axis of rotation of the central guide. The axis of rotation of the central guide coincides with the common pivot on the central sliding member when the hatch operating mechanism has been operated over an initial, predetermined distance sufficient to move the hatch clear of the opening. The hatch operating mechanism is stopped in this intermediate position, in order to allow release of the mechanical locking device and displacement of the hatch parallel to the guide means. In the second position, the central guide is indexed with an additional guide means extending parallel to the first and second guide means along the hatch. The parallel first, second and additional guide means will then allow the hatch to slide sideways relative to the central sliding member and the connecting elements held in position by the primary drive unit and the first arms. This allows the hatch to be opened sideways in either direction over a limited distance, until one connecting element reaches the end of the guide means. 
     Subsequently, the hatch is returned to the intermediate position, wherein the common pivot of the central sliding member coincides with the axis of rotation of the central guide. The central guide is then rotatable 90° from the second position to the first position to secure the mechanical locking device and prevent sideways movement of the hatch. The primary drive unit can then be operated to actuate the first arms in order to displace the hatch towards its open or closed position. 
     The hatch operating mechanism in this example can be provided with an optional secondary drive unit. The secondary drive unit can be arranged on at least one end of a connecting element and is drivingly connected to an adjacent guide means. The sideways displacement of the hatch can then be controlled by switches adjacent the hatch, by means of a hand held remote, or from a remote location within the vehicle. 
     A hatch operating mechanism according to a second embodiment comprises a pair of primary drive units connected to the vehicle along one and the same side of the opening. The primary drive units are mounted with a predetermined spacing, preferably at each end of the side of the opening along a common edge of the hatch. The drive units are attached to the vehicle adjacent the internal surface of the hatch when the hatch is in its closed position. The drive units extend a predetermined distance into the compartment, allowing the common plane of the axes of the first shafts of the first and second arms to extend out of the opening parallel to the common adjacent edge of the opening. Each primary drive unit is drivingly connected to a respective first shaft of the first ends of the respective first and second arms, directly or via a transmission mechanism for simultaneous rotation of the arms in predetermined, opposite directions. In this example, the first shaft at the first end of each first arm is arranged at a predetermined angle α relative to the plane of symmetry. The angle is selected within the range 0°&lt;α&lt;75°. The selection of suitable angles has been described above. In this case, the angles are arranged to converge towards the interior of the vehicle. 
     According to a second aspect of the invention, the object is achieved by a vehicle hatch, wherein the hatch comprises a hatch operating mechanism as described above. 
     According to a further aspect of the invention, the object is achieved by a vehicle, wherein the vehicle comprises a hatch with a hatch operating mechanism as described above. 
     An advantage of a hatch operating mechanism according to the invention is that the hatch can be opened substantially parallel to a side surface of the vehicle in multiple directions, both upwards and sideways. A further advantage is that the mechanism and any optional actuators are relatively compact and does not reduce the available space for luggage. The arrangement maximizes the available space for storage within the compartment and minimizes the space required by the hatch operating mechanism during displacement of the hatch. 
     Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples. 
       In the drawings: 
         FIG. 1  shows a side view of a vehicle provided with a hatch according to the invention; 
         FIG. 2  shows a hatch operating mechanism according to the invention; 
         FIG. 3  shows a plan view of the hatch operating mechanism in  FIG. 2 ; 
         FIG. 4  shows a plan view of a hatch and attached first and the second arm in  FIG. 2 ; 
         FIG. 5  shows a hatch operating mechanism according to the invention provided with a first alternative stabilizing device 
         FIG. 6  shows a hatch operating mechanism according to the invention provided with a second alternative stabilizing device according to the invention 
         FIG. 7  shows the hatch operating mechanism of  FIG. 6  in its initial, closed position; 
         FIG. 8  shows the hatch operating mechanism of  FIG. 6  in an intermediate position; 
         FIG. 9  shows the hatch operating mechanism of  FIG. 6  in its final, open position; 
         FIG. 10  shows a second embodiment of a hatch operating mechanism according to the invention; 
         FIG. 11  shows the hatch operating mechanism of  FIG. 10  in its initial, closed position; 
         FIG. 12  shows the hatch operating mechanism of  FIG. 11  in an intermediate position; 
         FIG. 13  shows the hatch operating mechanism of  FIG. 12  opened sideways. 
         FIG. 14  shows the hatch operating mechanism of  FIG. 11  in its final, open position. 
         FIG. 15  shows a second embodiment of a hatch operating mechanism according to the invention; and 
         FIG. 16  shows a plan view of a hatch and attached first and the second arm in  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION 
       FIG. 1  shows a side view of a vehicle provided with a hatch according to the invention. The vehicle in  FIG. 1  is a bus  100  which is provided with a first and a second storage means  110 ,  120  for luggage or other cargo to be transported by the bus  100 . The first and a second storage means  110 ,  120  comprise a first and a second hatch  111 ,  121 , respectively, arranged to cover a first and a second luggage compartment  112 ,  122  when the bus is being driven. In  FIG. 1  the first hatch  111  has been displaced upwards as indicated by the arrow A 2  and is shown in an open position where the first luggage compartment  112  is fully accessible. The first hatch  111  can be opened and closed manually, or by a primary drive unit  113  mounted onto an upper delimiting surface of the first luggage compartment  112  so that the full width of the compartment  112  can be accessed for loading and unloading. In  FIG. 1  the primary drive unit  113  is hidden by the first hatch  111  and is indicated in dashed lines. 
       FIG. 1  further shows the second hatch  121  displaced sideways as indicated by the arrow A 1 . The second hatch  121  is shown in a partially open position where the second luggage compartment  122  is partially accessible. A hatch operating mechanism that enables the hatches to be opened both upwards and/or sideways will be described in further detail below. 
     The first and second storage means  110 ,  120  are preferably, but not necessarily, identical and are provided with same size hatches, hatch operating mechanisms and drive units. 
       FIG. 2  shows a hatch operating mechanism  201  according to the invention. The hatch operating mechanism  201  is arranged to control the opening and closing movements of a hatch  202  for covering an opening in a vehicle  200 , as shown in  FIG. 1 . The mechanism comprises a first and a second arm  211 ,  221 , wherein each arm  211 ,  221  comprises a first end  212 ,  222  rotatably attached to a primary drive unit  203  on the vehicle  200 . Each arm  211 ,  221  has a second end  213 ,  223  rotatably attached to a connecting element  214 ,  224 , and a main extension  215 ,  225  connecting the first and second ends  212 ,  222 ;  213 ,  223 . The first and second ends of the respective first and second arm extend in opposite directions, giving the arms a general Z-shape. In this example, the hatch  202  is provided with hatch operating mechanism comprising a single, centrally placed primary drive unit  203  for rotating the first and second arms  211 ,  221 . The primary drive unit  203  can comprise a suitable motor and a transmission to which the first ends  212 ,  222  of the arms  211 ,  221  are connected. Examples of a suitable motor for this purpose can be an electric motor or a fluid driven motor, e.g. a hydraulic or pneumatic motor. The transmission is preferably, but not necessarily, a geared transmission. 
     The respective first and second connecting elements  214 ,  224  have opposite ends  214   a ,  214   b ;  224   a ,  224   b , wherein the opposite ends each connecting element  214 ,  224  are arranged to cooperate with a pair of parallel guide means  216 ,  217 ;  226 ,  227  fixed to the hatch  202 . The opposite ends  214   a ,  214   b ;  224   a ,  224   b  of the first and second connecting elements  214 ,  224  have suitable guide surfaces cooperating with mating guide surfaces  218   a ,  218   b ;  228   a ,  228   b  on the respective guide means  216 ,  217 ;  226 ,  227 . This arrangement allows the first and second connecting elements  214 ,  224  to be displaced relative to each other along the guide means  216 ,  217 ;  226 ,  227  during opening and closing of the hatch under the action of the first and second arms  215 ,  225 . 
     The connected first arm  211  and first connecting element  214  and the connected second arm  221  and second connecting element  224  are located in mirrored positions relative to a plane of symmetry (see  FIG. 3 ) at right angles to the parallel guide means  216 ,  226 ;  217 ,  227 . The example shows that the first and second arms  211 ,  221  comprise first ends with integral first shafts (see  FIG. 3 ), where the respective first ends and first shafts have a common axis. The first shafts are arranged to be mirrored in a common plane and have axes arranged at equal and opposite angles relative the plane of symmetry (see  FIG. 4 ; “a” and “P”). The second end of each first and second arm  211 ,  221  comprises an integral second shaft (see  FIG. 3 or 4 ; “ 243 / 244 ”) arranged to be rotatable about its own axis relative to its respective connecting element  214 ,  224  and which second shaft have an axis arranged parallel to its corresponding first shaft. 
     In operation, simultaneous rotation of the first and second arms  211 ,  221  of  FIG. 2  in predetermined and opposite directions is arranged to cause a primary displacement of the connecting elements  214 ,  224  away from each other along the guide means  216 ,  217 ;  226 ,  227  from a first position to a second position. In this second position, the arms  211 ,  221  have been rotated half way through an arc delimited by an initial position (see  FIG. 7 ) and a final position (see  FIG. 9 ) of the respective arm  211 ,  221  during the opening of the hatch  202 . Continued rotation of the first and second arms  211 ,  221  causes a subsequent secondary displacement of the connecting elements  214 ,  224  from their second positions back to their respective first positions, in order to move the hatch  202  from a closed to an open position. In this way the connecting elements perform a reciprocating movement along the guide means as the arms  211 ,  221  are rotated through the arc delimited by the initial position and the final position. 
     A hatch  202  provided with hatch operating mechanism comprising a single, centrally placed primary drive unit  203  can be provided with an optional secondary drive unit  204 . The secondary drive unit  204  can be arranged on at least one end  214   b  of a connecting element  214  and is drivingly connected to the adjacent guide means  217 . The secondary drive unit  204  can comprise a suitable motor that may be combined with a transmission means, for displacing the hatch. Examples of a suitable motor for this purpose can be an electric motor or a fluid driven motor, e.g. a hydraulic or pneumatic motor. The motor can drive the hatch directly, via a gear and pinion drive or indirectly via a transmission, such as a geared transmission, a linear motor, a linear telescoping actuator or similar. 
     During operation, the primary drive unit  203  of the hatch operating mechanism is first operated over an initial, predetermined distance sufficient to move the hatch  202  away from the side of the vehicle and clear of the opening covered by the hatch. When the hatch  202  reaches this intermediate position the primary drive unit  203  is stopped. Subsequent operation of the secondary drive unit  204  causes a sideways displacement of the hatch parallel to the guide means  216 ,  217 ;  226 ,  227 , substantially at right angles to the initial displacement caused by the primary drive unit  203 . The direction of the sideways movement is selected by selecting an operating direction for the secondary drive unit  204 . This allows the hatch to be opened sideways in either direction over a limited distance, until one connecting element  214 ,  224  reaches the end of the guide means  216 ,  217 ;  226 ,  227 . An advantage with this arrangement is that access can be provided to a limited portion of the storage or luggage compartment. 
     During operation of the hatch  202  between its closed and fully open position using the primary drive unit  203 , the secondary drive unit  204  is disconnected or free-wheeling. This allows the connecting elements  214 ,  224  to execute a reciprocating movement along the guide means  216 ,  217 ;  226 ,  227  during the rotation of the first and second arms  211 ,  221 . Sideways movement is not desired during operation of the primary drive unit  203 . This can be prevented by operating the secondary drive unit  204  in response to a position sensing means (not shown) in order to counteract any unintended sideways displacement of the hatch relative to the opening. 
       FIG. 3  shows a plan view of the hatch operating mechanism in  FIG. 2 . The reference numbering used in  FIG. 2  will be retained. The mechanism shown in  FIG. 3  comprises a first and a second arm  211 ,  221 , wherein each arm  211 ,  221  comprises a first end  212 ,  222  rotatably attached to the vehicle  200  via a primary drive unit  203 . Each arm  211 ,  221  has a second end  213 ,  223  rotatably attached to a connecting element  214 ,  224 , and a main extension  215 ,  225  connecting the first and second ends  212 ,  222 ;  213 ,  223 . The first and second ends of the respective first and second arm extend in opposite directions, giving the arms a general Z-shape. The hatch  202  is provided with hatch operating mechanism comprising a single, centrally placed primary drive unit  203  connected to a pair of first shafts  241 ,  242  for rotating the first and second arms  211 ,  221 . The primary drive unit  203  is mounted adjacent an opening  205  in the side of the vehicle  200  and comprises a suitable motor  203   a  and a transmission  203   b  to which the first ends  212 ,  222  of the arms  211 ,  221  are connected. The second ends;  213 ,  223  of the first and second arms  211 ,  221  are connected to first and second connecting elements (see  FIG. 2 ; “ 214 ,  224 ”). 
     The first arm  211  and the second arm  221  are located in mirrored positions relative to a plane of symmetry P at right angles to parallel guide means  216 ;  226  (see  FIG. 2 ). The first ends of each first and second arm  211 ,  221  comprise first shafts  241 ,  242  arranged in a common plane, which first shafts  241 ,  242  have axes arranged at equal and opposite angles α relative the plane of symmetry (see  FIG. 8 ). The second end of each first and second arm  211 ,  221  comprises a second shaft  243 ,  244  arranged to be rotatable about its own axis relative to its respective connecting element (not shown; see  FIG. 2 ). Each second shaft  243 ,  244  has an axis arranged parallel to its corresponding first shaft  241 ,  242  on the respective first and second arm  211 ,  221 . The length of first ends  212 ,  222  of the respective arm  211 ,  221  and the location of the primary drive unit  203  in relation to the opening  205  in the side of the vehicle  200  is selected to allow the first and second arms  211 ,  221  to swing clear of the edges of the opening  205  and along the side of the vehicle.  FIG. 3  shows a pair of arrows R indicating the direction of rotation of the first shafts  241 ,  242  in opposite direction for opening the hatch  202 . 
       FIG. 4  shows a plan view of a hatch  202  and attached first and second arms  211 ,  221 . The figure shows the first shafts  241 ,  242  at the first ends  212 ,  222  of the first and second arms  211 ,  221 , which first shafts  241 ,  242  have axes arranged at equal and opposite angles α from the plane of symmetry P. Similarly, the respective axes of the second shafts  243 ,  244  at the second ends  213 ,  223  of the first and second arms  211 ,  221  are arranged at equal and opposite angles α from the plane of symmetry P. 
       FIG. 5  shows a hatch operating mechanism according to the invention provided with a first alternative stabilizing device  430 . A hatch provided with a hatch operating mechanism comprising a single, centrally placed primary drive unit  203  as outlined in  FIG. 2  can be arranged to be opened by means of the primary drive unit  203  and the first and second arms  211 ,  221  as described above. 
     According to the first alternative example, shown in  FIG. 5 , the hatch operating mechanism is provided with a stabilizing arrangement  430  arranged to selectively prevent sideways displacement of the hatch  402  during the opening and closing operation. The stabilizing device  430  comprises a central sliding member  431  arranged to move between and parallel with the connecting elements  414 ,  424  adjacent a pair of first ends  414   a ,  424   a  of the connecting elements  414 ,  424  during actuation of the hatch  402 . A pair of struts  432 ,  433  are arranged to extend from pivots  434 ,  435  on the central sliding member  431  adjacent and equidistant from the first ends  414   a ,  424   a  of the connecting elements  414 ,  424  to pivots  436 ,  437  on a respective second end  414   b ,  424   b  of each connecting element  414 ,  424 . The central sliding member  431  is arranged to cooperate with a central guide  438  fixed to the hatch  402  and having an axis intersecting a central position of the guide means in the plane of symmetry P through the hatch  402 . During operation of the hatch  402 , as described in connection with  FIG. 2 , the reciprocating displacement of the connecting elements  414 ,  424  along the parallel guide means  416 ,  426 ;  417 ,  427  mounted on the hatch  402  causes the struts  432 ,  433  to act on the central sliding member  431 , which member will perform a corresponding reciprocating movement along the central guide  438 . As the central guide  438  is fixed to the hatch  402 , the central sliding member  431  can only move along the axis of the central guide  438 . This prevents the hatch  402  in this first alternative example from moving in a sideways direction while opening or closing the hatch  402 . 
       FIG. 6  shows a hatch operating mechanism as described in connection with  FIG. 2  provided with a second alternative stabilizing device  230 . The reference numbering used in  FIG. 2  will be retained for this example. The stabilizing device  230  comprises an elongate central rod  231  arranged between and parallel with the connecting elements  214 ,  224  of the hatch operating mechanism  201 . A pair of struts  232 ,  233  are arranged to extend from a first end  234  of the central rod  231  located adjacent one end of the connecting elements  214 ,  224  to the respective opposite ends of each connecting element  214 ,  224  adjacent the second end  235  of the central rod  231 . The struts  232 ,  233  are pivotable in a plane parallel to a plane through the parallel guide means  216 ,  217 ;  226 ,  227 . A pair of first pivot joints  236   a ,  236   b  allows the struts  232 ,  233  to be pivoted relative to the central rod  231 . A pair of second pivot joints  237   a ,  237   b  allows the struts  232 ,  233  to be pivoted relative to their respective connecting element  214 ,  224 . The first and second ends  234 ,  235  of the central rod  231  are arranged to cooperate with first and second stabilizing guides  238 ,  239  intersecting a central position of each guide means  216 ,  217 ;  226 ,  227 . During rotation of the first and second arms  211 ,  221  the central rod  231  is arranged to be displaced along its central axis in the plane of symmetry. The first end  234  of the central rod  231  is arranged to cooperate with the first guide  238  when the hatch  202  is in its closed position and its fully open position, i.e. whenever the first and second arms  211 ,  221  are in their end positions. The second end  235  of the central rod  231  is arranged to cooperate with the second guide  239  when the hatch  202  is between its closed position and its fully open position. In this example this occurs while the hatch  202  is approximately half way between the closed and open positions. In this way, the stabilizing central rod  231  will move linearly between the first stabilizing guide  238  and the second stabilizing guide  239  during operation of the primary drive unit  203  to open or close the hatch  202 . 
     In order to allow the hatch  202  to be opened sideways, the primary drive unit  203  is first operated to rotate the first and second arms  211 ,  221  over an initial, predetermined distance sufficient to move the hatch  202  away from the side of the vehicle and clear of the opening covered by the hatch. The primary drive unit  203  is stopped when the central rod  231  is located in an intermediate position (see  FIG. 5 ) out of contact with both the first and the second stabilizing guides  238 ,  239 , in order to allow displacement of the hatch  202  parallel to the guide means  216 ,  217 ;  226 ,  227  by operation of the secondary drive unit  204 . 
       FIGS. 7-9  show the operation of the inventive mechanism when moving the hatch from an initial closed position to a final open position via an intermediate position. In these figures, the numbering of  FIGS. 2 and 6  will be retained. 
       FIG. 7  shows the hatch operating mechanism  201  in its initial, closed position, wherein the hatch  202  is held in contact with the opening  205 , or frame, mounted in a substantially vertical side surface of the vehicle. The first and the second arm  211 ,  221  are rotatably attached to the primary drive unit  203  mounted within a compartment in the vehicle (not shown). Each arm  211 ,  221  is rotatably attached to a respective first and second connecting element  214 ,  224 , which connecting elements are slidable relative a pair of opposed and parallel guide means  216 ,  217 ;  226 ,  227 . This arrangement allows the first and second connecting elements  214 ,  224  to be displaced relative to each other along the guide means  216 ,  217 ;  226 ,  227  during opening and closing of the hatch under the action of the first and second arms  215 ,  225 . In  FIG. 7  the first and second connecting elements  214 ,  224  are located adjacent each other in an initial position. The first and second connecting elements  214 ,  224  are connected by a stabilizing device  230  comprising an elongate central rod  231  arranged between and parallel with the connecting elements  214 ,  224  of the hatch operating mechanism  201 . A pair of struts  232 ,  233  are arranged to extend from a first end of the central rod  231  located adjacent one end of the connecting elements  214 ,  224  to the respective opposite ends of each connecting element  214 ,  224  adjacent the second end of the central rod  231 . In the initial position, the first end  234  of the central rod  231  is arranged to cooperate with the first stabilizing guide  238  intersecting a central position of a pair of adjacent lower guide means  217 ;  227 . In the closed position, the hatch  202  is held in contact with the frame  205  by means of the first and the second arm  211 ,  221 , in order to prevent vertical and outwards movement. The cooperating central rod  231  and the first stabilizing guide  238  assist in preventing sideways, or lateral movement of the hatch  202 . The hatch and the frame surrounding the opening can also be provided with cooperating or mating surfaces to prevent relative movement and/or for sealing purposes. 
       FIG. 8  shows the hatch operating mechanism  201  in an intermediate position. Actuation of the primary drive unit  203  will initiate rotation of the first and second arms  211 ,  221 , wherein the angled arrangement of the driven first shafts (see  FIG. 3 ; “ 241 ,  242 ”) of the respective first arm will cause the hatch  202  to be displaced outwards, away from the opening  205 . Rotation of the first and second arms  211 ,  221  causes the first and second connecting elements  214 ,  224  to be displaced away from each other along the guide means  216 ,  217 ;  226 ,  227  during the initial opening of the hatch. 
     In order to allow the hatch  202  to be opened sideways, the primary drive unit  203  is first operated to rotate the first and second arms  211 ,  221  over an initial, predetermined distance sufficient to move the hatch  202  away from the side of the vehicle and clear of the opening covered by the hatch. The primary drive unit  203  is stopped when the central rod  231  is located in the intermediate position shown in  FIG. 8 . In the intermediate position the ends of the central rod  231  out of contact with both the first and the second stabilizing guides  238 ,  239  intersecting the guide means  216 ,  217 ;  226 ,  227 . In order to displace the hatch  202  parallel to the guide means  216 ,  217 ;  226 ,  227  the secondary drive unit  204  is operated. In the example shown in  FIG. 8 , the secondary drive unit  204  is mounted on the first connecting element  214  and acts on an adjacent guide means  217  by means of a suitable drive mechanism to displace the hatch  202  in a desired lateral direction. In this example, the hatch can be displaced laterally until one of the connecting elements reaches the end of its corresponding guide means. The hatch can therefore only be partially opened in the lateral direction, as indicated in  FIG. 1 . This is an advantage if luggage is loaded into the compartment in accordance with a particular destination, so that only a limited portion of the compartment need be exposed in adverse weather conditions. The feature can also be used for preventing access to some parts of the compartment during loading or unloading. 
       FIG. 9  shows the hatch operating mechanism  201  in its final, open position, wherein the hatch  202  is fully open. Continued rotation of the first and second arms  211 ,  221  from the intermediate position in  FIG. 8  is arranged to continue the primary displacement of the connecting elements  214 ,  224  away from each other along the guide means  216 ,  217 ;  226 ,  227  towards a second position  214 ′,  224 ′ (shown in dashed lines). In this second position, the arms  211 ,  221  have been rotated half way through an arc delimited by the initial position (see  FIG. 7 ) and the final position shown in  FIG. 9 . Continued rotation of the first and second arms  211 ,  221  causes a subsequent secondary displacement of the connecting elements  214 ,  224  from their respective second positions back to their respective first positions, in order to move the hatch  202  to its fully open position. In this way the connecting elements perform a reciprocating movement along the guide means  216 ,  226 ;  217 ,  227  as the first and second arms  211 ,  221  are rotated through the arc delimited by the initial position and the final position. In order to close the hatch, the first and the second arm are simultaneously rotated in the reverse directions, from the final position to the initial position. 
       FIG. 10  shows a hatch operating mechanism  301  according to the invention provided with a third alternative stabilizing device  330 . A hatch  302  is provided with a hatch operating mechanism  301  comprising a pair of primary drive units  303   a ,  303   b , which hatch is arranged to be opened by means of the primary drive units  303   a ,  303   b  and a pair of first and second arms  311 ,  321 . The function and arrangement of the first and second arms  311 ,  321  is substantially the same as outlined in  FIGS. 2-4  above, with the difference that two spaced apart primary drive units  303   a ,  303   b  are used instead of a single primary drive unit. Optionally, the arrangement in  FIG. 10  can of course also be operated with a single primary drive unit. 
     According to the third alternative example, the hatch operating mechanism  301  is provided with a stabilizing arrangement  330  comprising a mechanical locking device arranged to selectively prevent sideways displacement of the hatch  302  during the opening and closing operation. The stabilizing device  330  comprises a central sliding member  331  arranged to move between and parallel with the connecting elements  314 ,  324  adjacent a pair of first ends  314   a ,  324   a  of the connecting elements  314 ,  324  during actuation of the hatch  302 . A pair of struts  332 ,  333  are arranged to extend from a common pivot  334  on the central sliding member  331  adjacent and equidistant from the first ends  314   a ,  324   a  of the connecting elements  314 ,  324  to pivots  336 ,  337  on a respective second end  314   b ,  324   b  of each connecting element  314 ,  324 . The central sliding member  331  is arranged to cooperate with a central guide or slot  338  in a rotatable member  335  in the stabilizing member  330 . The rotatable member  335  and the central guide  338  are arranged to act as said locking device. The central guide  338  in the rotatable member  335  is initially located in a first position with an axis intersecting a central position of two parallel first and second guide means  316 ,  317  in the plane of symmetry through the hatch. The function of the first and second guide means has been described in connection with e.g.  FIG. 2  above (see ref. no. “ 216 ,  217 ”). During operation of the hatch  302  the primary drive units  303   a ,  303   b  rotates a first and a second arm  311 ,  321  (indicated in dashed lines) connected to the connecting elements  314 ,  324 . The connecting elements  314 ,  324  will perform a reciprocating movement along the guide means  316 ,  317  as the first and second arms  311 ,  321  are rotated through and arc delimited by their initial and the final positions. The reciprocating displacement of the connecting elements  314 ,  324  causes the struts  332 ,  333  to act on the central sliding member  331 , which will perform a corresponding reciprocating movement along the central guide  338  at right angles to the first and second guide means  316 ,  317 . As the locking means is mounted on the hatch the central sliding member  331  can only move along the axis of the central guide  338  while the hatch  302  is displaced by the first and the second arm  311 ,  321 . This prevents the hatch  302  in this example from moving in a sideways direction while opening or closing the hatch using the primary drive units  303   a ,  303   b.    
     The central guide  338  and the rotatable member  335  are rotatable 90° from the first position to a second position about an axis at right angles to the plane of the hatch  302 , in order to release the mechanical locking device. In the second position the axis of the central guide  338  is parallel to the first and second guide means  316 ,  317  attached to the hatch. Rotation of the central guide  338  is possible when the common pivot  334  of the central sliding member  331  is located coinciding with the axis of rotation the rotatable member  335  comprising the central guide  338 . The axis of rotation of the rotatable member  335  comprising the central guide  338  coincides with the common pivot  334  on the central sliding member  331  when the hatch operating mechanism has been operated over an initial, predetermined distance sufficient to move the hatch clear of the opening. The hatch operating mechanism is stopped in this intermediate position, in order to allow release of the mechanical locking device and displacement of the hatch  302  parallel to the guide means  316 ,  317 . In the second position, the central guide  338  is indexed with an additional guide means  318  extending parallel to the first and second guide means  316 ,  317  along the hatch. 
     The rotatable member  335  in this example is mounted to be rotated relative to a holder  336  fixed to the hatch  302 . The holder  336  has slots which are indexed with either end of the central guide  338  of the rotatable member  335 , which is shown in its locking position in  FIG. 10 . The holder  336  has additional slots which are indexed with either end of the central guide  338  and the additional guide means  318  when the rotatable member  335  has been rotated 90° from its first, locking position to its second, released position to allow sideways displacement. The parallel first, second and additional guide means  316 ,  317 ,  318  will then allow the hatch to slide sideways relative to central sliding member  331 , while the connecting elements  314 ,  324  held in position by the primary drive units  303   a ,  303   b  and the first and the second arm  311 ,  321 . This allows the hatch  302  to be opened sideways in either direction over a limited distance, until one connecting element reaches the end of the guide means. 
     Subsequently, the hatch  302  is returned to the intermediate position, wherein the common pivot  334  of the central sliding member  331  coincides with the axis of rotation of the rotatable member  335  comprising the central guide  338 . The central guide  338  is then rotated 90° from the second position to the first position to secure the mechanical locking device and prevent sideways movement of the hatch. The primary drive units  303   a ,  303   b  can then be operated to actuate the first and the second arm  211 ,  321  in order to displace the hatch  302  towards its open or closed position. 
     The hatch operating mechanism in this example can be provided with an optional secondary drive unit  304 . The secondary drive unit  304  can be arranged on at least one end of a connecting element  314  and is drivingly connected to an adjacent guide means  317 . The sideways displacement of the hatch can then be controlled by switches adjacent the hatch, by means of a hand held remote, or from a remote location within the vehicle. 
       FIGS. 11-14  show the operation of the inventive mechanism when moving the hatch from an initial closed position to a final open position via an intermediate position. In these figures, the numbering of  FIG. 10  will be retained. 
       FIG. 11  shows the hatch operating mechanism  301  in its initial, closed position, wherein the hatch  302  is held in contact with the opening  305 , or frame, mounted in a substantially vertical side surface of the vehicle. The first and the second arm  311 ,  312  (indicated in dashed lines) are rotatably attached to their respective primary drive unit  303   a ,  303   b  mounted within a compartment in the vehicle (not shown). Each arm  311 ,  312  is rotatably attached to a respective first and second connecting element  314 ,  324 , which connecting elements are slidable relative a pair of opposed and parallel guide means  316 ,  317 . This arrangement allows the first and second connecting elements  314 ,  324  to be displaced relative to each other along the guide means  316 ,  317  during opening and closing of the hatch under the action of the first and second arms  315 ,  325 . In  FIG. 11  the first and second connecting elements  314 ,  324  are located adjacent each other in an initial position. The first and second connecting elements  314 ,  324  are connected by a stabilizing device  330  comprising a central sliding member  331  arranged to move between and parallel with the connecting elements  314 ,  324  during actuation of the hatch  302 . A pair of stabilizing struts  332 ,  333  are arranged to extend from a common pivot  334  on the central sliding member  331  to pivots  336 ,  337  on each connecting element  314 ,  324  (see  FIG. 10 ). The central sliding member  331  is arranged to cooperate with a central guide or slot  338  in a rotatable member  335  in the stabilizing member  330 . The rotatable member  335  and the central guide  338  are arranged to act as said locking device. The central guide  338  in the rotatable member  335  is initially located in a first position extending along an axis intersecting a central position of two parallel first and second guide means  316 ,  317  in the plane of symmetry through the hatch. In its closed position, the hatch  302  is held in contact with the frame  305  by means of the first and the second arm  311 ,  312 , in order to prevent vertical and outwards movement. The central sliding member  331  is arranged in a position remote from, in this case above, the axis of rotation of the rotatable member  335  so that sideways movement of the hatch  302  is prevented. The hatch and the frame surrounding the opening can also be provided with cooperating or mating surfaces to prevent relative movement and/or for sealing purposes. 
       FIG. 12  shows the hatch operating mechanism  301  in an intermediate position. Actuation of the primary drive units  303   a ,  303   b  will initiate rotation of the first and second arms  311 ,  312 , wherein the angled arrangement of the driven first shafts of the respective first arm will cause the hatch  302  to be displaced outwards, away from the opening  305 .  FIG. 10  shows an embodiment using separate primary drive units, but the arrangement of the drive shafts and the principle of operation is the same as described for  FIG. 3  above. Rotation of the first and second arms  311 ,  312  causes the first and second connecting elements  314 ,  324  to be displaced away from each other along the guide means  316 ,  317  during the initial opening of the hatch. In order to allow the hatch  302  to be opened sideways, the primary drive units  303   a ,  303   b  are first operated to rotate the first and second arms  311 ,  312  over an initial, predetermined distance sufficient to move the hatch  302  away from the side of the vehicle and clear of the opening covered by the hatch and towards the intermediate position. The primary drive units  303   a ,  303   b  are stopped when the common pivot on the central sliding member  331  is arranged in a position coinciding with the axis of rotation of the rotatable member  335 . The central guide  338  and the rotatable member  335  can then be rotated 90° from its first, locking position to its second, released position. In this position the central guide  338  is indexed with the additional guide means  318 . The parallel first, second and additional guide means  316 ,  317 ,  318  will then allow the hatch to slide sideways relative to the central sliding member  331  and the connecting elements  314 ,  324  held in position by the primary drive units  303   a ,  303   b  and the first and the second arm  311 ,  312 . 
     In order to displace the hatch  302  parallel to the guide means  316 ,  317 ,  318  a secondary drive unit  304  as indicated in  FIG. 10  can be operated. In the example shown in  FIG. 10 , the secondary drive unit  304  is mounted on the first connecting element  314  and acts on an adjacent guide means  317  by means of a suitable drive mechanism to displace the hatch  302  in a desired lateral direction. In this example, the hatch can be displaced laterally until one of the connecting elements reaches the end of its corresponding guide means. The hatch can therefore only be partially opened in the lateral direction, as indicated in  FIG. 1 . This is an advantage if luggage is loaded into the compartment in accordance with a particular destination, so that only a limited portion of the compartment need be exposed in adverse weather conditions. The feature can also be used for preventing access to some parts of the compartment during loading or unloading. 
       FIG. 13  shows the hatch operating mechanism  301  displaced from the intermediate position shown in  FIG. 12 , wherein the hatch  302  is opened sideways. The connecting elements  314 ,  324  and the stabilizing struts  332 ,  333  with their central sliding member  331  are held in position by the fixed primary drive units  303   a ,  303   b . As the hatch  302  is displaced into the position shown in  FIG. 13 , the two parallel first and second guide means  316 ,  317  will slide relative to the connecting elements  314  and the additional guide means  318  will slide relative to the central sliding member  331  in the central guide  338  in the indexed rotatable member  335 . 
       FIG. 14  shows the hatch operating mechanism  301  in its final, open position, wherein the hatch  302  is fully open. Continued rotation of the first and second arms  311 ,  312  from the intermediate position in  FIG. 12  is arranged to continue the primary displacement of the connecting elements  314 ,  324  away from each other along the guide means  316 ,  317  towards a second position  314 ′,  324 ′ (shown in dashed lines). In this second position, the arms  311 ,  312  have been rotated half way through an arc delimited by the initial position (see  FIG. 11 ) and the final position shown in  FIG. 13 . Continued rotation of the first and second arms  311 ,  312  causes a subsequent secondary displacement of the connecting elements  314 ,  324  from their respective second positions back to their respective first positions, in order to move the hatch  302  to its fully open position. In this way the connecting elements perform a reciprocating movement along the guide means  316 ,  317  as the first and second arms  311 ,  312  are rotated through the arc delimited by the initial position and the final position. In order to close the hatch, the first and the second arm are simultaneous rotated in the reverse directions, from the final position to the initial position. 
       FIG. 15  shows a hatch operating mechanism  401  according to a further embodiment of the invention. A hatch  402  is provided with a hatch operating mechanism  401  comprising a pair of primary drive units  403   a ,  403   b , which hatch is arranged to be opened by means of the primary drive units  403   a ,  403   b  and a pair of first and second arms  411 ,  421 . The function and arrangement of the first and second arms  411 ,  421  is substantially the same as outlined in  FIGS. 2-4  above, with the difference that two spaced apart primary drive units  403   a ,  403   b  are used instead of a single primary drive unit. Actuation of the primary drive units  403   a ,  403   b  will initiate rotation of the first and second arms  411 ,  421 , wherein the angled arrangement of the driven first shafts of the respective first arm will cause the hatch  402  to be displaced outwards, away from the opening  405 .  FIG. 14  shows an embodiment using separate primary drive units, but the arrangement of the drive shafts and the principle of operation is the same as described for  FIG. 3  above. Rotation of the first and second arms  411 ,  421  causes a primary displacement of the first and second connecting elements  414 ,  424  towards each other along the guide means  416 ,  417  during the initial opening of the hatch. Continued rotation of the first and second arms  411 ,  421  will displace the connecting elements  414 ,  424  towards a second position  414 ′,  424 ′ (shown in dashed lines). In this second position, the arms  411 ,  421  have been rotated half way through an arc delimited by an initial, closed position and a final, open position. Continued rotation of the first and second arms  411 ,  421  from the second position causes a subsequent secondary displacement of the connecting elements  414 ,  424  towards each other from their respective second positions back to their respective first positions, in order to move the hatch  402  to its fully open position. In this way the connecting elements perform a reciprocating movement along the guide means  416 ,  426  as the first and second arms  411 ,  421  are rotated through the arc delimited by the initial position and the final position. In order to close the hatch, the first and the second arm are simultaneous rotated in the reverse directions, from the final position to the initial position. 
       FIG. 15  further shows a hatch provided with a stabilizing device  430 . The stabilizing device  430  comprises an elongate central rod  431  arranged between and parallel with the connecting elements  414 ,  424  of the hatch operating mechanism  401 . A pair of struts  432 ,  433  are arranged to extend from the central rod  431  located between one end of the connecting elements  414 ,  424  to the respective opposite ends of each connecting element  414 ,  424 . The struts  432 ,  433  are pivotable in a plane parallel to a plane through the parallel guide means  416 ,  417 . A pair of first pivot joints  436   a ,  436   b  allows the struts  432 ,  433  to be pivoted relative to the central rod  431 . A pair of second pivot joints  437   a ,  437   b  allows the struts  432 ,  433  to be pivoted relative to their respective connecting element  414 ,  424 . The central rod  431  is arranged to cooperate with first and second stabilizing guides  438 ,  439  intersecting a central position of each guide means  416 ,  417 . During rotation of the first and second arms  411 ,  421  the central rod  431  is arranged to be displaced along its central axis in the plane of symmetry. The first end of the central rod  431  is arranged to cooperate with at least the first guide  438  when the hatch  402  is in its closed position and its fully open position, i.e. whenever the first and second arms  411 ,  421  are in their end positions. The second end of the central rod  431  is arranged to cooperate with the second guide  439  when the hatch  402  is between its closed position and its fully open position. In this way, the stabilizing central rod  431  will move linearly in at least one the first stabilizing guide  438  and the second stabilizing guide  439  during operation of the primary drive units  403   a ,  403   b  to open or close the hatch  402 . 
       FIG. 16  shows a plan view of a hatch  402  and attached first and second arms  411 ,  421  from  FIG. 14 . The figure shows the first shafts  441 ,  442  at the first ends of the first and second arms  411 ,  421 , which first shafts  441 ,  442  have axes arranged at equal and opposite angles α from the plane of symmetry P. Similarly, the respective axes of the second shafts  443 ,  444  at the second ends of the first and second arms  411 ,  421  are arranged at equal and opposite angles α from the plane of symmetry P. 
     It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.