The present invention relates to a denesting apparatus for denesting a stack of trays or cups or other hollow receptacles stacked together. The invention specifically relates to a support unit for supporting the stack of trays or cups, before being denested, to re- lieve the gravitational force on a number of lower trays or cups in the stack.

Background of the Invention

Relieving the gravitational force on the number of lower trays or cups decreases the risk of the trays or cups being too tightly engaged, which otherwise may inhibit denesting of the lowermost tray or cup from the trays or cups in the stack above.

Support units for relieving the gravitational force on a number of lower trays or cups in a stack are known. Various solutions may be used. One solution comprises a plural- ity of disks being inserted into a tiny space between adjacent edges of one tray and a neighbouring tray in the stack.

Another solution discloses a plurality of blades being inserted into the tiny space be- tween adjacent edges of one tray and a neighbouring tray in the stack. Insertion of the disks or blades is performed by a rotational movement or a translational movement of the disks or blades and is in fixed correlation with denesting elements for denesting the lowermost tray or cup of the stack. Fixed correlation between the disks or blades being inserted into the tiny space between adjacent edges of one tray and a neighbour ing tray in the stack and denesting of the lowermost tray or cup of the stack must be maintained during operation of the denesting apparatus.

Otherwise, denesting cannot be performed at a high pace. Denesting at a high pace is the main reason for using a denesting apparatus, apart from not needing a person for denesting the trays or cups. If denesting the lowermost tray or cup or if supporting the stack of trays or cups for one reason or the other is faulty, it may be necessary to man ually lift the entire stack of trays or cups to a position where the lowermost tray or cup is supported by the upper support unit such as disks or blades. However, if the denest- ing unit or the support unit is stopped in a position where part of the stack is still sup- ported, it is not possible to elevate the stack, before the support units are returned to a position, where the support units are not inserted into the tiny space between adjacent edges of one tray and a neighbouring tray in the stack. Repositioning the support units must be performed by a person, before the person is capable of elevating the stack of trays or cups to a positon, where the lowermost tray or cup is supported by the support units. This takes time, and non-operation of the denesting apparatus becomes a bottle- neck to subsequent operations such as filing the trays or cups with foodstuff.

Object of the Invention

It is an object of the present invention to reduce the risk of the operation of the denest- ing apparatus becoming a bottleneck for subsequent operation, when a fault occurs during denesting of trays from the denesting apparatus. It is furthermore an object of the invention to reduce interaction between a person and the denesting apparatus for thereby reducing a person interacting with the denesting apparatus, which may influ- ence the correlation between the disks or blades being inserted into the tiny space be- tween adjacent edges of one tray and a neighbouring tray in the stack and denesting of the lowermost tray or cup of the stack.

Furthermore it is an object of the invention to provide a construction which quickly allows displacement of the stack of receptacles in case jamming occurs in the denest- ing apparatus.

Description of the Invention

The invention addresses this by providing a support unit, intended for constituting part of a denesting apparatus, and for supporting a stack of trays, cups or other receptacles to be denested in the denesting apparatus, the support unit comprising a lever rod or lever arm having at least one first surface and at least one second surface, said surfac- es to be inserted, during operation of the denesting apparatus, into a space between edges of neighbouring receptacles in the stack of receptacles, the lever arm or the lev- er rod capable of displacing the first and second surfaces from a retracted position in relation to the stack of receptacles to a projected position in relation to the stack of receptacles, and from the projected position in relation to the stack of receptacles to the retracted position in relation to the stack of receptacles, wherein the displacement of the lever arm or the lever rod from the projected position to the retracted position is performed by elevating the stack of receptacles, whereby the edges of the receptacles engage the second surface and urges the lever arm or lever rod towards the retracted position when passing the second surfaces during elevation of the stack of receptacles, and where the displacement of the lever arm or the lever rod from the retracted posi- tion to the projected position is performed by the lever arm or lever rod being biased by a spring load towards said projected position.

Displacing the first and the second surfaces, i.e. the distal tip from the projected posi- tion to the retracted position, and vice versa, without operating the motorised actuator, and displacing the first and second surfaces from the retracted position to the project- ed position by the first and second surfaces being biased by a spring load, results in the first and the second surfaces being easily displaced away from the projected posi- tion, when repositioning the stack of receptacles by moving the stack upwards against the dispensation direction, while the distal tip is being forced back to the projected position, during normal operation, when repositioning has been concluded.

Further advantageous embodiments are disclosed in dependent claims.

However, according to a further embodiment of the invention, the stack of receptacles has a longitudinal direction, the first and the second surfaces are provided on a blade provided on the lever arm or the lever rod, the first surface is arranged substantially perpendicular relative to the longitudinal direction of the stack of receptacles, and the second surface is arranged in an oblique direction relative to the longitudinal direction of the stack of receptacles, where the first and the second surfaces are positioned adja- cent to each other at an acute angle relative to each other, where the acute angle of said blade engage the stack of receptacles.

The first and the second surface to be inserted, during operation of the denesting appa- ratus, into a space between edges of neighbouring receptacles in the stack of recepta- cles, may be provided in various shapes. As one example of the shape of the first and the second surfaces, the first and the second surfaces are forming a blade on a lever arm or a lever rod. The first surface may be arranged substantially perpendicular to the longitudinal direction of the stack, where the longitudinal direction is similar to a vertical oriented stack and where the second surface is arranged in an oblique position to the longitudinal direction of the stack, when the stack is arranged in a vertical posi- tion.

As another example of a shape of the first and the second surfaces, the first and the second surfaces form a blunt end of a lever rod or a lever arm. As yet another example of the shape of the first and second surfaces, the first and second surfaces forms a pointed end of a lever rod or a lever arm. As still yet another example of the shape of the first and second surfaces, the first and second surfaces form a sharp edge of a lever rod or a lever arm. Any surface capable of being inserted into a space between edges of neighbouring receptacles in the stack of receptacles may be used as a surface for counteracting and relieving the gravitational force on a number of lower receptacles.

According to a still further embodiment of the invention, displacement of the first and the second surfaces, when the first and the second surfaces, when displaced without operating the motorised actuator from the retracted position to the projected position, and vice versa, is provided by the first and second surfaces pivoting around a pivot axle extending through a lever rod.

A pivotal rotational displacement of the first and the second surfaces is a reliable manner of movement, and the risk of the first and the second surfaces being non- displaceable is limited. Pivoting the first and the second surfaces only limits the mass to be displaced.

According to a further embodiment of the invention, the spring load, is biasing the first and second surfaces towards a projected position in relation to the receptacles, and where a stop is provided, said stop limiting projection of the first and second sur faces, and said stop defining a furthermost extension of the first and second surfaces towards the projected position in relation to the receptacles. A pivotal rotational displacement of the motorised actuator is a reliable manner of movement, and the risk of the first and second surfaces being non-displaceable is lim ited. Pivoting the motorised actuator eliminates a need for added features for the mo torised actuator operating the first and second surfaces. According to a still further other embodiment of the invention, displacement of the lever arm or the lever rod is provided by sliding the lever arm or the lever rod (19) along a slide axle or along a guide track.

According to still further embodiment of the invention, the slide axle or guide track extends through a fixed element of the denesting apparatus.

According to a further preferred embodiment of the invention, the spring load, is biasing the first and second surfaces towards a projected position in relation to the receptacles, and where a stop is provided, said stop limiting projection of the first and second surfaces, and said stop defining a furthermost extension of the first and second surfaces towards the projected position in relation to the receptacles.

Preferably, the stop is limiting projection of the first and second surfaces by stopping one of the following movements of the first and second surfaces along displacement of the first and second surfaces towards the projected position: stopping pivoting of the first and second surfaces around the pivot axle though the lever rod, stopping piv- oting of the motorised actuator around the pivot axle through the fixed element of the denesting apparatus, stopping sliding of the first and second surfaces along the slide axle in prolongation of the lever rod, stopping sliding of the motorise actuator along the fixed slide axle of the denesting apparatus, stopping pivoting of the lever arms around the pivot axle through the fixed element of the denesting apparatus.

The object of the invention may also be obtained by a denesting apparatus for denest- ing a stack of trays, cups or other receptacles nested together, said denesting apparatus comprising at least one support unit according to any of the above embodiments.

The object of the invention is also obtained by a method for repositioning in a denest- ing apparatus a stack of receptacles such as trays or cups nested together, said stack of receptacles being positioned in the denesting apparatus, and said at least one support unit comprising a surface being inserted between neighbouring receptacles, and for supporting at least part of the stack of receptacles during normal use, said method comprising the following steps: - elevating the stack of receptacles to a position, where a lowermost receptacle of the stack is in a position above the first and second surfaces of at least one support unit for supporting at least part of the stack during normal operation of the denesting appa- ratus,

- during elevation of the stack of receptacles, the first and second surfaces of the at least one support unit displacing from a projected position to a retracted position in relation to the stack of receptacles, automatically without operating the motorised ac- tuator, and the displacement counteracting a bias of a spring load,

- after elevation of the stack of receptacles, the first and second surfaces of the at least one support unit displacing from the retracted position to a projected position in rela- tion to the stack of receptacles, automatically without operating the motorised actua- tor, and the displacement being enacted by the spring load.

In the following, as example of a receptacle like a tray or a cup, a tray will be used. However, using a tray of example of a receptacle is not to be construed as a limitation to other receptacles like cups.

Description of the Drawing

Fig. l is a sketch of an embodiment of a support unit according to the invention,

Fig. 2 is a sketch of another embodiment of a support unit according to the invention, Fig. 3 is a sketch of yet an embodiment of a support unit according to the invention, Fig. 4 is a sketch of yet an embodiment of a support unit according to the invention, Fig. 5 is a drawing of yet an embodiment of a support unit according to the invention.

Detailed Description of the Invention

Fig. 1 is sketch showing a possible embodiment of a support unit 1 in cross-section for supporting a number of trays 2 in a stack, before a lowermost tray 3 of the stack is denested from a bottom of the stack. In the figure, only a left side of a stack of trays is shown. A denesting unit configured as a rotating disk 4 (denesting wheel) is shown. The rotating disk is mounted on a shaft 5. The shaft 5 is rotated by a motor (not shown), either directly or via a belt (not shown). During normal operation of the denesting apparatus, rotation of the shaft 5 results in a corresponding rotation of the disk 4. Other types of denesting units than a rotating disk may be used together with the support unit 1 shown in Fig. 1. The rotating disk 4 has a cam 6 supporting an edge 7 of a lowermost tray 3, maintain ing a lowermost tray 3 in the stack before being denested from the stack. The rotating disk also has a knife 8 for being inserted, during rotation of the shaft 5 and the disk 4, into a space 9 between the edge 7 of the lowermost tray 3 and an edge 10 of a neigh- bouring tray 11 in the stack. During rotation counter-clockwise of the shaft 5 and thus of the disk 4, the knife 8 enters into the space 9 between the edge 7 of the lowermost tray 3 and an edge 10 of a neighbouring tray 11 in the stack. During further rotation counter-clockwise of the shaft 5 and thus of the disk 4, the cam 6 displaces away from the edge 7 of the lowermost tray 3. Thereby, the lowermost tray 3, by gravity, is sepa- rated from the neighbouring tray 11 and the lowermost tray 3 is denested from the stack of trays. The process of denesting a lowermost tray from the stack of trays, as described above, is known to the skilled person in relation to denesting apparatuses.

During normal operation of the denesting apparatus, the support unit 1 may be dis- placed translational in a bearing 12, upwards and downwards as shown by the bidirec tional arrow A. In the embodiment shown, the support unit 1 has a surface in the shape of a blade 13 intended for being inserted into a space 14 between an edge 15 of one tray 16 and an edge 17 of a neighbouring tray 18. The support unit has a lever rod 19 onto which the blade 13 is attached or which the blade 13 constitutes part of/integral with.

The first surface 32 and the second surface 33 may be provided in other shapes than a distal tip 34 of the blade 13, where the first surface 32 is substantially perpendicular relative to the longitudinal direction of the stack of trays 2. The second surface 33 is oblique relative to the longitudinal direction of the stack of trays 2. The first surface 32 and second surface 33 may be positioned adjacent to each other at an acute angle relative to each other forming the distal tip 34, where a pointed end of the blade 13, provided with an acute angle which may engage the stack of trays 2. As one example of another shape of the first and second surfaces 32,33, the first and second surfaces 32,33 forms a blunt end of the lever rod 19, and in which embodiment the lever rod 19 is not provided with a blade as such. As another example of the first and second surfaces 32,33, the first and second surfaces 32,33, form a pointed end of the lever rod 19, in which embodiment the lever rod 19 is not provided with a blade as such. As yet another example of the first and second surfaces 32,33, the first and sec- ond surfaces 32,33, forms a sharp edge of the lever rod 19, in which embodiment the lever rod 19 is not provided with a blade as such. In the following part of the detailed description of the invention, a blade will be used as the example illustrated in fig. 1 of the shape of the first and second surfaces 32,33, without limiting other possible shapes of the first and second surfaces 32,33, as mentioned above.

When the lever rod 19 is displaced upwards, the blade 13 is inserted into a space 14 between the edges 15,17 of the two neighbouring trays 16,18. When the support unit 1 is displaced further upwards, all trays above the blade 13 will be elevated by the blade’s 13 first surface 32. When all trays above the first surface 32 of the blade 13 are elevated by the blade 13, trays below the blade 13 are relieved of the gravitational force of the upper trays. Relieving the lower trays below the blade 13 of the gravita- tional force of the upper trays above results in the space 10 between the lowermost tray 3 and the neighbouring tray 11 not being limited by a gravitational force from the entire stack of trays, but only limited by the limited stack of trays below the blade 13. The knife 8 may therefore more easily be inserted into the space 8 between the edges 7,10 of the lowermost tray 3 and the neighbouring tray 11 and thereby increase the reliability of the denesting process. Relieving the trays below the blade of the gravita- tional force of the upper trays, as described above, is known to the skilled person in relation to denesting apparatuses.

However, if for one reason or the other, the stack of trays 2, either the entire stack of trays 2 or only the extended stackof trays 2 above the blade 13 or only the limited stack of trays 2 below the blade 13, is blocked, it is necessary firstly to stop operation of the denesting apparatus, secondly to reposition the entire stack of trays 2 and third- ly to start operation of the denesting apparatus again.

Repositioning the entire stack of trays 2 is often performed by a person pushing the entire stack of trays 2 upwards by elevating the lowermost tray to a position above the blade 13. In known denesting apparatuses, repositioning the entire stack of trays 2 always require the blade 13 not being in a projected position, that is, the blade 13 not being in a position between edges of neighbouring trays. According to the prior art, if the blade is in position between edges of neighbouring trays, and when repositioning the entire stack of trays is needed, firstly the blade 13 must be displaced from the projected position to a retracted position, by manually dis placing the blade from the positon between the edges of the neighbouring trays, or by incremental operation of the denesting apparatus for displacing the lever rod or lever arm, onto which the blade is attached. Secondly, repositioning of the entire stack of trays is performed by a person pushing the entire stack of trays upwards, by elevating the lowermost tray, to a position above the blade. Thirdly, the blade must be displaced from the retracted position to the projected position, by manually displacing the blade to a position between the edges of the neighbouring trays, or by incremental operation of the denesting apparatus for displacing the lever rod or lever arm, onto which the blade is attached. Possibly, displacing the blade from the retracted position to the pro- jected position must be done, while manually holding the entire stack of trays in the elevated position. This is difficult. Finally, operation of the denesting apparatus must be reinitiated.

According to the present invention, if the blade 13 is in a projected position between edges 15,17 of neighbouring trays 16,18, and when repositioning the entire stack of trays 2 is needed, repositioning of the entire stack of trays 2 is still performed by a person pushing the entire stack of trays 2 upwards, by elevating the lowermost tray 3, to a position above the blade 13 .

However, during elevation of the entire stack of trays 2, even if the blade 13 is in a projected position between edges 15,17 of neighbouring trays 16,18, the blade 13 is displaced to a retracted position.

In Fig. 1, displacement of the blade 13 is performed by the bearing 12 of the lever rod 19 pivoting around a pivot axle as shown by the arrow P. The pivoting is caused by the trays engaging the second surface of the lever arm or rod, whereby the edges of the trays urges the lever arm/rod away from the stack. As the lever arm/rod is pivot- ably mounted, the lever arm/rod swings out from the stack towards the retracted posi- tion. Pivoting of the lever rod 19 is biased by a helical coil spring 20 positioned be- tween the support unit 1 and a non-displaceable part 21 of the denesting apparatus, compared to the displaceable mounting of the bearing 12 in relation the non- displaceable part of denesting apparatus. When the entire stack of trays has been repo- sitioned, the helical coil spring 20 automatically biases the bearing 12 and thus auto- matically displaces the blade 13 from the retracted position to the projected position in relation to the stack of trays, and thereby inserting the blade into a space between edg- es of neighbouring trays. Other types of springs may be used.

Accordingly, when having to reposition the entire stack of trays by elevating the entire stack of trays, in the present invention there is no need initially to manually or by a motorised actuator to displace the blade from a projected position to a retracted posi- tion. Also, when the entire stack of trays has been repositioned by elevating the entire stack of trays, in the present invention there is no need subsequently to manually or by a motorised actuator displacing the blade from the retracted position to the projected position.

The lever rod 19 can be operated using a motorised actuator arranged in the bearing 12. When the lever rod is displaced during normal operation, the lever rod is displaced from the retracted position to the projected position, and vice versa, when operating the motorised actuator. Thereby during normal operation displacing the first and sec- ond surfaces 32,33.

The lever rod 19 can still be displaced without operating the motorised actuator, when the motorised actuator is arranged in the bearing 12, and said lever rod 19 extending from the motorised actuator arranged in the bearing 12. The lever rod 19 is still capa- ble of pivoting around a pivot axle extending through said lever rod even though the motorised actuator is present.

A stop 22 is intended for limiting pivoting of the blade 13 in relation to the lever rod 19. Limiting pivoting assures that the blade 13, when biased by the spring 20 to the projected position, is positioned in position, and is maintained in a position, suitable for the blade 13 to be inserted between edges of neighbouring trays of the stack of trays.

In the embodiment shown, where the blade is in the projected position, the blade is in a position, where the blade extends substantially horizontally. In other embodiments, the stop of the non-displaceable part is provided so that the blade in the projected po- sition, is in a position, where the blade extends inclined and with a tip of the blade pointing upwards.

Fig. 2 is a sketch showing an alternative embodiment of a support unit 1 for support- ing a number of trays in a stack (not shown). Reference is made both to the descrip tion of Fig. 1 and to Fig. 1 itself for a description of the position in relation to the stack of trays and for a description of the denesting unit configured as a rotating disk The support unit 1 shown in Fig. 2 is not capable of pivoting around an axle, when the blade 13 comprising a first surface 32 and second surface 33, is to be displaced from the projected position to the retracted position and from the retracted position to the projected position. In the embodiment shown in Fig. 2, the pivot axle is provided ex- tending through the lever rod 19. Pivoting of the blade 13 from the projected position to the retracted position is biased by a coil spring 20 positioned between the blade 13 and the lever rod 19. When the entire stack of trays has been repositioned, the spring 20 biases the blade 13 from the retracted position to the projected position. Other types of springs may be used.

Fig. 2 can also be provided with a motorised actuator arranged in the bearing 12, where the lever rod 19 extends from the motorised actuator. The displacement of the lever rod 19 is displaced automatically without operating the motorised actuator. The lever rod 19 is capable of pivoting around the pivot axle extending through the top of said lever rod 19. When the lever rod 19 are displaced during normal operation and displaced from the retracted position to the projected position, and vice versa, the lev- er rod 19 are operated using the motorised actuator for displacement. Thereby during normal operation displacing the first and second surfaces 32,33.

Fig. 3 is a sketch showing yet a further alternative embodiment of a support unit for supporting a number of trays in a stack. In the figure, no stack of trays is shown. Ref erence is made both to the description of Fig. 1 and to Fig. 1 itself for a description of the position in relation to the tack of trays and for a description of the denesting unit configured as a rotating disk. The support unit shown in Fig. 3 is capable of sliding along a slide axle 23, when the blade 13 comprising a first surface 32 and second surface 33, is to be displaced from the projected position to the retracted position and from the retracted position to the projected position. Sliding from the projected position to the retracted position is caused by the ef dges of the trays urging the blade away. The movement is biased by a helical coil spring 20 positioned between a stop 22 and an end of the slide axle 23, said end of the slide axle being at an opposite side of the helical spring 20 compared to where the stop 22 is positioned along the slide axle. When the entire stack of trays has been repositioned, the spring automatically biases the blade 13 as such from the retracted position to the projected position. Other types of springs than a helical coil spring may be used.

Fig. 3 can also be provided with a motorised actuator arranged in the bearing 12, where the lever rod 19 extends from the motorised actuator. The displacement of the lever rod (19) can still be displaced automatically without operating the motorised actuator arranged in the bearing 12. The lever rod 19 slides along the slide axle 23 or along the guide track extending in prolongation of the lever rod 19.

The lever rod (19), which is extending from the motorised actuator, can be displaced during normal operation, by operating the motorised actuator provided for displacing the lever rod (19). Thereby during normal operation displacing the first and second surfaces (32,33) of the blade 13 on the lever rod 19.

Fig. 4 is a sketch showing yet a further embodiment of a support unit for supporting a number of trays in a stack. In the figure, no stack of trays is shown. Reference is made both to the description of Fig. 1 and to Fig. 1 itself for a description of the position in relation to the tack of trays and for a description of the denesting unit configured as a rotating disk.

The blade 13 shown in Fig. 4 is capable of sliding along a slide axle 23, when the blade 13 comprising a first surface 32 and second surface 33, is to be displaced from the projected position to the retracted position and from the retracted position to the projected position. Sliding of the blade 13 from the projected position to the retracted position is caused by the edges of the trays urging the blade away. The movement is biased by a helical coil spring 20 positioned between a bearing 12 of the lever rod 19 and an end of the slide axle 13, said end of the slide axle being at an opposite side of the helical spring 20 compared to where the bearing 12 is positioned along the slide axle 23. When the entire stack of trays has been repositioned, the spring automatically biases the blade from the retracted position to the projected position. Other types of springs than a helical coil spring may be used.

Fig. 4 also shows a support unit 1, where the support unit 1 comprises a motorised actuator arranged in the bearing 12, where the lever rod 19 extends from the motorised actuator. The displacement of the lever rod 19 may be displaced automatically without operating the motorised actuator arranged in the bearing 12, by sliding along a slide axle 23 or along a guide track extending through a fixed element of the denesting ap- paratus as discussed above. The lever rod 19, when displaced during normal opera- tion, can also be operated by the motorised actuator, when displacing the lever rod 19, thereby during normal operation displacing the first and second surfaces 32,33.

Fig. 5 is a drawing showing yet a further embodiment of a support unit for supporting a number of trays in a stack. In the figure, no stack of trays is shown.

Function of the support unit shown in Fig. 5 differs somewhat from the function of the support units shown in Fig. 1-4. The support unit shown in Fig. 5 has a blade 13 com prising a first surface 32 and second surface 33, extending between lower ends of two L-shaped lever arms 24,25. The first surface 32 is substantially perpendicular relative to the longitudinal direction of the stack of trays 2. The second surface 33 is oblique relative to the first surface 32. The two L-shaped lever arms 24,25 are pivotally at tached, to a pivot axle 26, in a support block 27. A push element 28 extends between upper ends of the L-shaped lever arms 24,25. In the embodiment shown, the push el ement is pivotally attached, via a pivot axle 29, to the upper ends of the L-shaped lev er arms 24,25.

During normal operation, the blade 13 is sequentially elevating part of the stack of trays by the blade 13 being displaced from a retracted position, as shown in Fig. 5, to a projected position, where the lower ends of the L-shaped lever arms 24,25 are lifted. Lifting of the lower ends of the L-shaped lever arms 24,25 is performed by a cam shaft 30 with a cam 31, said cam 31 being eccentrically positioned on the cam shaft 30. The cam 31 pushes the push element 28 every time an outermost part of the cir cumference of the cam 31 is abutting the push element 28 during rotation of the cam shaft 30 and the cam 31.

When the blade 13, during a stop, needs to be displaced from a projected position to a retracted position, the lever arms are pivoting automatically around the pivot axle 26, when the stack of trays (not shown) is elevated by pushing the lowermost tray up- wards. The edges of the trays engage the second surface 33. A spring (not shown) is provided in the support block 27, said spring biasing the blade form the retracted posi- tion to the projected position, Possibly, the spring is provided as a torsional force of the pivot axle 26, said pivot axle 26 thus functioning as a torsional spring, eliminating a need for separate springs such as shown in Fig. 1-4.

Fig. 5 also shows a support unit 1, where the support unit 1 comprises a motorised actuator arranged in the support block 27, where the lever arms 24,25 extends from each side of the support block 27. The displacement of both lever arm 24,25 when operated by the motorised actuator, can be displaced automatically without operating the motorised actuator. The lever arms 24,25 are pivoting around the pivot axle 26 or the lever arms 24,25 are being displaced along a guide track.

The lever arms 24,25 are displaced during normal operation by operating the motor ised actuator arranged in the support block 27 for displacing both lever arms 24,25. Thereby during normal operation displacing the first and second surfaces (32,33) on the blade 13 of the lever rod (19) or lever arm 24,25.