WO2003022115A2

WO2003022115A2 - Gas doner grill with a protective glass-pane embodiment

Info

Publication number: WO2003022115A2
Application number: PCT/TR2002/000053
Authority: WO
Inventors: Vehbi Varlik; Nuri Coskun Irfan
Original assignee: Inoksan Mutfak Sanayi Ve Ticaret A.S.
Priority date: 2001-09-10
Filing date: 2002-09-10
Publication date: 2003-03-20
Also published as: WO2003022115A3; DE10297205T5; DE10297205B4

Abstract

The present invention is related to a gas doner grill embodiment that ensures doner to be roasted healthily, homogeneously, and ideally in a hygienic medium; wherein it contains an apparatus where a central protective glass-pane (1) or two additional side-wing panes (2, 3) with the same characteristics besides said pane (1) are placed in front of heaters (15) so as to make a partial circular movement on the doner grill.

Description

GAS DONER GRILL WITH A PROTECTIVE GLASS-PANE EMBODIMENT

TECHNICAL FIELD

The present invention is related to a gas doner grill embodiment that ensures doner to be roasted healthy, homogeneously, and ideally in a hygienic medium.

The present invention is particularly related to an apparatus where a removable central protective glass-pane or two additional side-wing panes with same characteristics are placed in front of heaters so that they make a partial circular movement on the doner grill.

PRIOR ART

Doner grills are presently being utilized in order to roast meat materials in fast- food centers, restaurants, and so on. These doner grills consist of a spit, which is positioned on a heating main body, and a lower table. Said vertical arranged spit approaches the heater by being balanced by means of adjustment spots positioned on top of the grill. In case a doner fastened to a spit in a doner grill has a conical shape, the meat at the higher part of the spit are roasted quicker when compared to the meat at the lower body of said spit; thus leading to an inhomogeneous roasting.

Regarding the conventional doner grills; fat that spreads from the roasted meat affects the heating radiant negatively by penetrating in through the porous screen, and leads to hardly cleaned wastes, as there are many complex sites on the screen. An unhygienic and unpleasant circumstance is faced as a result of this.

In addition to the aforementioned matters; waste or unburned gases arising from imbalances or from ripped or worn-out radiant screens penetrate into the roasted meat. They lead to carcinogen affects to negatively influence the human health.

Regarding particularly the presently used gas doner grills; since the heat coming from the heating mechanism directly reaches the meat, a homogeneous roasting can not be performed, and even in some circumstances, some spots on a roasted meat becomes coalificated. In addition, since heating apparatuses are not produced according to the conical shape of doner meat, some meat spots are roasted more than the other are.

Also, as improper tables are used underneath a spit, a piece of meat that is sliced from a doner falls out of said table and an unpleasant circumstance is arrived at regarding cleanliness and hygiene concerns.

BRIEF DESCRIPTION OF INVENTION

The present invention is related to a oOπer-grill embodiment that eliminates the aforementioned drawbacks.

The present invention aims to produce a gas doner grill embodiment that ensures donerto be cooked healthily, homogeneously, and ideally in a hygienic medium.

In order to realize this objective, the doner grill according to the present invention comprises a central protective pane positioned in front of gaseous radiant; pane connecting sheet-irons to connect said pane to the main body; fresh air-heat directing sheet-irons positioned on both sides of radiant elements; pane fixing lower slot whereon the central protective pane is settled and a pane fixing upper slot to support said pane by top; and a pane sliding sheet-iron to support the central protective pane from both sides and to make said pane easily fastened and removed.

In one preferred embodiment of the present invention; the central protective pane that is produced with concavity towards the gas radiant elements to comply with the shape of the doner does spread the heat that comes from the radiant elements homogeneously on its surface so that it softens said heat and ensures the meat fastened to the grill to be roasted homogeneously and prevents coalification of said meat. Said pane also keeps the fat that spreads during roasting from penetrating into the radiant elements; as a result of this, it prevents said radiant elements from getting fated and thus from getting damaged in order to obtain a clean and hygienic roasting medium.

Said pane also prevents waste and unburned gases from penetrating into the meat so as to obtain a human-health friendly roasting; whereas the heat collected on the mass of glass causes unburned gases to enter into a second burning process (secondary combustion) in order to minimize the waste gas percentage and to effectively benefit from the heat that spreads from the heater.

The surface of the central protective pane that faces the heat supply is designed with a rough surface to increase the heating surface area with the aim of burning unburned gases more effectively while the other surface thereof is smooth for easy cleaning and hygienic and clean appearance.

Said central protective pane is designed to have a gap between the gas radiant and itself so that air can enter in-between in order to provide gas radiant elements continuously with fresh air to ensure a healthy combustion.

The central protective pane is connected to the main body with a pair of pane connecting sheet-iron having plurality of openings to obtain above mentioned gap without obstructing air flow towards gas radiant.

A heat-fresh air directing sheet-iron is present that - without obstructing fresh air to enter therein- aims to prevent heat and waste or unburned gases to leave from said gap and to direct them towards the central pane so that unburned gases are subjected to combustion once more and waste gases are sent away to exterior.

In another preferred embodiment of the present invention, there are provided a lighter and pilot system for igniting burners and a safety system, with magnet valve, which prevent gas flow to burners when the burners go out accidentally.

A pane sliding sheet is realized so that the central protective pane is easily taken out by being moved upwardly.

In another preferred embodiment, the main body of the present invention is movable horizontally and stepwise manner over the lower body thereof for adjusting the distance between the doner and gas radiant according to the quantity of the doner. In another preferred embodiment, a spit joint mechanism having a spherically shaped spit movement body attached to the lower end of the spit, an upper movement cup accommodating said spit movement body and shaped correspondingly to the spit movement body, a sealing rubber embodied between the roller bearing and motor connection sheets for providing sealing is provided. The upper movement cup and accordingly the spit movement body in connection therewith are rotated via a load bearing shaft rotating in an axial roller bearing by an actuation of a motor or a user via a manual handle.

In another preferred embodiment, a spit locking mechanism having a spit upper housing accommodating the spit and a spit upper housing bearing the spit upper housing is disposed thereto and a spit locking ring for stabling the spit in said spit upper housing is used for having improved stabling and locking of the spit.

A tray is present that completely covers the lower main body in order to keep roasted/sliced meat parts from falling into the rear of oOπer-grill and from falling under the heating elements.

A heat-prevention sheet is embodied on the upper spit connection group in order to prevent some parts that are manually loosened/tightened from getting overheated and from probable burns that a user may be exposed to.

A stopper and a stopper bush is present on the tray to take the fat that leaks from the meat into the fat drawer and the fat collected within said fat drawer is controllably removed here from.

A perforated filter sheet is present in the tray to make the fat filtered into the tray located thereunder.

An fat isolation sheet is present in order to prevent possible damages that the fat from the spitted meat can impose on the motor group located thereunder.

Almost all of the parts are designed to be easily fastened and removed in order to perform grill's general cleaning easily. In an alternative embodiment of the present invention; wing panes are embodied on the right and left of the main body in addition to the central pane in order to prevent the fat from spreading to the exterior, to prevent the negative affects of possible winds, and to minimize the heat loss. Said embodiment can be utilized in doner grills presently used in the sector.

In this embodiment, the side and central panes are fastened to the main body by means of a special hinge mechanism and are designed so that to make a partial circular movement. In case the central pane is damaged, the right wing pane can easily be fastened in place of the central pane so as to provide a continuity in operating the doner grill.

BRIEF DESCRIPTION OF FIGURES

Figure 1 gives a perspective drawing showing the general appearance of the doner grill with a single protective pane.

Figure 2 gives a perspective drawing showing the heating group with a single protective pane assembled thereto.

Figure 3 gives a two-dimensional drawing showing the doner grill with a single protective glass from the top.

Figure 4 gives a perspective drawing showing the dismantled heating group of the doner grill with a single protective pane.

Figure 5 gives a two-dimensional drawing showing the gas roasting apparatus from the top.

Figure 6 gives a two-dimensional drawing showing the central protective sheet and the pane connecting sheet from the top.

Figure 7 gives a two-dimensional drawing showing the connection of the upper pane fixing sheet and the pane connecting sheet from the top.

Figure 8 gives a two-dimensional drawing showing the heat directing sheet from the top. Figure 9 gives the details of -A- shown in Figure 6.

Figure 10 gives the details of -B- shown in Figure 7.

Figure 11 gives a perspective drawing showing a general appearance of the doner grill having central and wing panes.

Figure 12 gives a two-dimensional drawing showing a top appearance of the doner grill having central and wing panes.

Figure 13 gives a two-dimensional drawing showing a frontal view of panes.

Figure 14 gives a perspective drawing showing the appearance of the upper hanger sheet and the upper hinge mechanism.

Figure 15 gives a perspective drawing showing the appearance of the lower hanger sheet and the lower hinge mechanism.

Figure 16 gives a perspective view of roller bearing-rail arrangement for moving heating means in horizontally and stepwise manner over the lower part.

Figure 17 gives a perspective view of spit joint mechanism for moving the spit in any direction easily.

Figure 18 gives a perspective view of spit locking mechanism.

REFERENCE NUMBERS

1. central protective glass-pane;

1.1 central pane profile; 1.2 pane rear surface;

1.3 pane front surface;

2. right wing pane;

3. left wing pane;

4. upper hinge mechanism; 4.1 jagged hinge slot;

4.2 hinge tube;

4.3 nut cap; 4.4 bolt;

5. upper hanger sheet;

6. lower hinge mechanism; 6.1 smooth hinge slot; 6.2 hinge tube;

6.3 nut cap;

6.4 bolt;

7. main body;

8. lower hanger sheet; 9. air-heat directing sheet;

10. pane connecting sheet;

11. pane sliding sheet;

12. radiant connecting sheet;

13. pane fixing upper slot; 14. pane fixing lower slot;

15. gas radiant;

16. radiant ignition lighter;

17. air flow controlling wing; 17.1 air flow channel; 18. tray;

19. stopper;

20. stopper bush;

21. perforated filter sheet;

22. fat drawer; 23. fat directing and isolation sheet;

24. heat preventing sheet;

25. spit mechanism;

26. gas valve;

27. gas valve connection; and 28. lower body.

29. Magnet valve (Safety valve)

30. Lighter 31. Roller bearing

32. Nut

33. Bolt

34. Adjustment bolt 35. Rail

36. Ball stopping bolt

37. Setskur coupling nut

38. Motor

39. Sealing rubber 40. Load bearing shaft

41. Load bearing profile

42. Spit locking ring

43. Spit movement body

44. Upper movement shaft 45. Oil isolation cup

46. Axial roller bearing

47. Spit upper housing

48. Spit upper housing bearing

49. Spit adjustment profile

DETAILED DESCRIPTION OF INVENTION

The present doner grill contains a central protective pane (1) positioned in front of the gas radiant (15); pane connecting sheets (10) connecting said pane (1 ) to the main body (7); fresh air-heat directing sheet (9) formed aside to radiant elements (15); pane fixing lower slot (14) whereon the central protective pane (1 ) is settled and the pane fixing upper slot (13) supporting this pane and the pane sliding sheet (11) supporting the central protective pane (1) from both sides and providing an easy fit and removal thereof.

Figure 1 gives a general view of the doner grill with a single protective glass-pane. According to this Figure, meats are prevented from falling down into the rear of the grill or from falling down to the exterior, thanks to the tray (18) covering the lower body (28) entirely. Also, in order to prevent the fat that comes from meat from leaking into the motor that is present within the lower body (28) to rotate the doner, an fat directing and isolation sheet (23) is designed on the part where the spit faces the lower tray. In this manner, the fat that accumulates in the meat is collected in the tray (18) after they are filtered downward by means of the perforated filter sheet (21) positioned on the tray (18). If necessary; the stopper (19) that is formed on the upper surface of the tray (18) is opened by opening the stopper bush (20) that accommodates said stopper and the collected fat is taken into the fat drawer (22) and poured out afterwards. The heat preventing sheet (24) that is embodied on the spit mechanism (25) and is extending along the lower part of said mechanism (25) horizontally prevents the meat's heat from the parts of the spit mechanism (25) that are in contact with user hands. Also the gas flow is stopped by a gas valve (26) that is preferably positioned on the right side of the doner grill, gas reaches the radiant elements (15) through the gas valve connection (27). On the other hand, if the fire goes out unintentionally the gas flow is prevented by a magnet valve (29).

Figure 2 gives a view of a heating group assembled with a single protective glass

(1). Accordingly, a central protective pane (1) -preferably from seran glass- that is designed with concavity towards the radiant elements (15) is fixed to the main body (7) by means of the pane connecting sheets (10) so that a gap is provided in front of the meat roasting mechanism. The pane connecting sheets (10) connected to both sides of the main body (7) are designed with orifices thereon to provide the gas radiant elements (15) with fresh air inflow. As the heat in the spot where the radiant elements (15) are present is much higher as compared with the exterior, an air pressure difference is formed in-between and thus the fresh air at the exterior is drawn in through the orifices, as shown with arrows (a), and the radiant elements (15) are continuously fed with fresh air.

Figure 3 gives a top view of the doner grill with a single protective pane (1). As it is shown in this Figure, a heat-fresh air directing sheet (9) extending to the radiant (15) spot on two contrary ends of the roasting mechanism in the interior section prevents the heated fresh air from going out through the orifices on the pane connection sheet (10) -as shown with arrows (b)- and directs heat and waste gases formed as a result of combustion towards the pane without preventing fresh air to flow in -as shown with arrows (a)-. Waste gases -as a combustion product- can be taken out by being directed upwards -as shown with arrows (c)- according to the principle that heated air is risen. In this manner, a chimney drawing force is established.

Figure 4 gives a view of a disassembled doner grill with a single protective pane. The air flow wings (17) that are used for directing heat and burned gases and that are embodied on the upper side of each gas radiant (15) are seen in this Figure. Thanks to the special air flow channels (17.1 ) formed in these wings, combusted air formed as a result of combustion by means of the radiant ignition lighter (16) of the upper gas radiant elements passes through these channels to ignite the lower positioned gas radiant elements (15) and thus the entire rows are ignited in sequence.

Figure 5 gives a top view of the gas roasting mechanism. These roasting radiant elements (15) are fastened to the main body (7) by means of the radiant connecting sheets (12) embodied on two contrary ends. If desired, one-rowed or different radiant elements can be utilized in place of these two-rowed gas radiant elements shown in this Figure. Figures 6 and 7 give the views of the protective pane fixing mechanism. According to this Figure, the central protective pane (1) is positioned on the edges by means of the pane sliding sheets (11) formed on the ends facing the central pane (1) of the pane connecting sheets (10) and by means of the pane fixing upper slot (13) from the top. The pane sliding sheets (11) are embodied on both sides of the central protective pane (1) and between this pane (1) and the pane connecting sheets (10) and extends along the right and left edges of the central protective pane (1). As for the pane fixing upper slot (13), it is located between the pane sliding sheets (11) and extends along the lower and upper edges of the pane (1). If desired, with an upward movement, the central protective pane (1) can be moved along the horizontal axis on the sliding channels (11.1) of the pane sliding sheet (11 ) of the central pane (1 ).

Figure 8 gives a close view of the fresh air-heat directing sheet (9). According to this Figure, the radiant connecting sheet (12) is connected to one end of the fresh air-heat directing sheet that is embodied horizontally on both exterior-facing sides of the radiant elements (15) so as to have a length that is equal to the heights of the radiant elements (15). As the other end extends towards the gas radiant elements (15), the heat on the radiant elements (15) are directed back to the central protective pane (1 ). The magnet valve (safety valve) (29) and location thereof also can be seen from the figure.

As it can be understood from Figures 9 and 10, the pane fixing lower and upper slots (13, 14) are fixed by being attached to the pane sliding sheet (11).

Figure 11 gives a general view of the doner grill with central and concave shaped wing panes. According to this Figure, one central protective pane (1) and wing panes (2, 3) are formed on right and left sides of the main body (7). In case the central pane (1) is broken or becomes unusable, the right wing pane (2) can be fastened in place of the former.

Figure 12 gives a top view of the doner grill with central (1) and wing panes (2, 3).

As it can also be seen from this Figure; all of said panes (1 , 2, and 3) are pivotable, i.e. capable to perform a horizontal, gradual angular motion by means of a special hinge mechanism (4, 6). Although a one-ordered radiant heater is shown in this Figure, other roasting mechanisms such as two-ordered angular radiant elements can also easily be utilized if desired, once the dimension of these panes are arranged.

Figure 13 gives a general view of the wing panes (2) and the hinge mechanism (4.6) thereof. These panes (1 , 2, 3) are surrounded by a profile and are fastened to the profile (1.1) by the pane fixing upper slot (13) and by the pane fixing lower slot (14) from top and bottom, respectively. As it can also be seen from this Figure, said panes (1 , 2, and 3) are fastened to the main body (7) by engaging the upper and lower hanger sheets (5, 8) formed on the profile (1.1) to the smooth and jagged hinge slots (6.1 , 4.1) of the hinge mechanisms (4, 6) attached beforehand to the main body (7).

Figures 14 and 15 give a disassembled view of the hinge mechanism (4, 6) providing the angular movement. The upper hinge mechanism (4) contains a jagged hinge slot (4.1) whereon channels are formed; a hinge tube (4.2); a nut cap (4.3) to connect said mechanism to the grill and a bolt (4.4). Thanks to said jagged hinge slot (4.1); the central (1), right (2), and left (3) panes can be hold in a fixed position according to the diameter of the meat to be roasted. In exactly the same way, the lower hinge mechanism (6) contains a smooth hinge slot (6.1) as different from the jagged slot of the upper mechanism (4).

In Figure 16, there is given the bearing-rail mechanism. The mechanism is coupled to the lower body (28) via roller bearings (31 ), nuts (32) and bolts. The gap of the roller bearings (31) is adjusted by a adjustment bolt (34). The rail (35) can be moved horizontally front and back over the roller bearings (31).

For keeping the heating means stable at a predetermined distance from the doner and having a stepwise embodiment, a ball stopping bolt (36) present in the roller bearing-rail mechanism is used. The ball stopping bolt (36) is coupled to the roller bearing-rail mechanism by a bolt coupling nut (37).

In the Figure 17, there is given a spit joint mechanism enabling the spit to be rotated by a motor (38). The motor (38) rotates an axial roller bearing (46), a load bearing shaft (40), a load bearing profile (41), an upper movement cup (44) and an fat isolation cup (45) all together at the same time and a sealing rubber (39) is embodied between the roller bearing (46) and motor connection sheets for providing sealing. The spit movement body (43) is attached to the upper end of the spit (32) and shaped spherically and accordingly the upper movement cup (44) is shaped correspondingly to the spit movement body (43) in a way that it receives the spit movement body (43) by substantially covering the all surfaces thereof.

By means of the spit movement body (43) shaped spherically and upper movement cup (44) combination, the spit can be moved in any direction slightly over the upper movement cup (44) and removed easily and also can easily be rotated by a user in case of not being able to use the motor since the spit movement body (43) does not have any direct connection with the motor's shaft.

In the Figure 18, there is given a spit locking mechanism providing the secure stabling of the spit. In this embodiment, the spit is disposed to the spit upper housing (47) rotating in a spit upper housing bearing (48) and stabled by a spit locking ring (42). The spit upper housing (47) is rotated by an actuation from a motor or a user turning a manual handle embodied on the upper part of the spit locking mechanism in case of no electricity etc. The spit locking mechanism is attached to a spit adjustment profile (49) which is enabling users to adjust the distance between the spit and heating means, i.e. gas radiant and is embodied therebetween movable horizontally.

Although the present invention has been shown and described in terms of a preferred embodiment, it will be appreciated that changes and modifications will be evident to those skilled in the art from knowledge of the teachings of the present invention. Such changes and modifications, which do not depart from the spirit, scope and teachings herein, are deemed to fall within the purview of the invention as set forth in the appended claims.

Claims

1. A gas doner grills having a main body (7) and gas radiant (15) for roasting meats like doner, comprises,

a central protective glass-pane (1 ) positioned in front of said gas radiant (15);

a pane connecting iron-sheet (10) connecting said central protective pane (1) to said main body (7) by providing a gap therebetween without obstructing fresh air flow towards said gas radiant (15);

a fresh air-heat directing sheet (9) for directing heat and waste or unburned gases towards said central protective pane (1) without preventing fresh air to flow in and by preventing heat and waste or unburned gases from flowing out of said gap;

a pane fixing lower slot (14) for locating said central protective pane (1) thereon and a pane fixing upper slot (13) for supporting said pane at the top;

a pane sliding sheet (11) for supporting said central protective pane (1) from both sides and providing an easy fit and removal of said pane;

a heat preventing sheet (24) positioned on the spit mechanism (25) for preventing the handled parts of the spit mechanism (25) from getting overheated;

and a tray (18) extending under said gas radiant elements (15) to prevent roasted meat parts to fall down rear the doner grill and under the heaters.

2. An apparatus according to claim 1; characterized in that said central protective pane (1) is made of seran glass and in concave shape for transmitting heat coming from gas radiant elements (15) to doner meat most effectively.

3. An apparatus according to claim 1 ; characterized in that said central protective pane (1) comprises a rough rear surface (1.2) and a smooth front surface (1.3).

4. An apparatus according to claim 1 , characterized in that said pane connecting sheet (10) comprises plurality of openings thereon and is positioned vertically on the right and left sides of the main body (7).

5. An apparatus according to claim 1 ; characterized in that said fresh air-heat directing sheet (9) is extending vertically along both exterior-facing sides of the radiant elements (15).

6. An apparatus according to claim 1; characterized in that said pane fixing lower slot (14) and a pane fixing upper slot (13) are positioned between the pane sliding sheets (11) and are extending along the lower and upper edges of the central protective pane (1 ), respectively.

7. An apparatus according to claim 1 ; characterized in that said pane sliding sheet (1 1 ) is embodied between pane the connecting sheets (10) and the central protective pane (1 ) by extending along the right and left edges of the central protective pane (1 ) and comprises sliding channels (11.1).

8. An apparatus according to claim 1 ; characterized in that said tray (18) is positioned on the lower body (28) by covering the entire lower body (28).

9. An apparatus according to claim 1 ; characterized in that said heat preventing sheet (24) is positioned on the spit mechanism (25) and is extending along the lower part of said mechanism (25) horizontally.

10. An apparatus according to claim 1 ; characterized in that a stopper bush (20) and a stopper (19) covering said stopper bush (20) is formed on the upper surface of the tray (18) for transferring the fat leaking from meat an fat drawer (22).

11. An apparatus according to claim 1 ; characterized in that it comprises a spit joint mechanism having a spherically shaped spit movement body (43) attached to the lower end of the spit, an upper movement cup (44) accommodating said spit movement body (43) and shaped correspondingly to the spit movement body (43), a sealing rubber (39) embodied between the roller bearing (46) and motor connection sheets for providing sealing, all rotated via a load bearing shaft (40) rotating in an axial roller bearing (46) by an actuation of a motor (38) or a user via a manual handle.

12. An apparatus according to claim 1 ; characterized in that it comprises a spit locking mechanism having a spit upper housing (47) accommodating the spit and a spit upper housing bearing (48) the spit upper housing (47) is disposed thereto and a spit locking ring (42) for stabling the spit in said spit upper housing (47).

13. A gas doner grills for roasting meats like doner, comprises,

a pivotable central protective glass-pane (1 ) positioned in front of said gas radiant elements (15);

pivotable wing panes (2, 3) embodied on right and left sides of the main body (7) in addition to the central glass-pane for preventing meat's fat from spreading to the exterior, the negative affects of possible winds, and minimizing the heat loss;

lower and upper hanger sheets (5, 8) fastened to said central protective pane (1 ) and wing panes (2, 3); and

lower and upper hinge mechanisms (4, 6) connecting them to the main body (7) in a way that the central protective pane (1) and side wing panes (2, 3) become pivotally movable, easy to fit and remove.

14. An apparatus according to claim 13; characterized in that the central protective pane (1 ) and the side wing panes (2, 3) are in concave shape.

15. An apparatus according to claim 13, characterized in that it comprises a pane profile (1.1) surrounding and accommodating said central protective pane (1 ) and side wing panes (2, 3).

16. An apparatus according to claim 13; characterized in that said upper hinge mechanism (4) comprises a jagged hinge slot (4.1), a hinge tube (4.2), a nut cap (4.3), and a bolt (4.4) to provide the pane with a gradual circular movement.

17. An apparatus according to claim 13; characterized in that said lower hinge mechanism (6) comprises a smooth hinge slot (6.1), a hinge tube (6.2), a nut cap (6.3), and a bolt (6.4).

18. An apparatus according to claim 13; characterized in that it comprises lower and upper hanger sheets (5, 8) that connect panes (1 , 2, 3) to the main body

(7) by engaging said panes into the smooth and jagged slots (6.1 , 4.1 ) of the lower and upper hinges, respectively.

19. An apparatus according to claim 1 and 13; characterized in that it comprises a bearing-rail mechanism comprising a rail (25) and plurality of roller bearings (31), nuts (32) and bolts (33) for connecting the rail (25) to the lower body (28) movably over the lower part (28).

20. An apparatus according to claim 13; characterized in that the right wing pane (2) can be assembled in place of the central protective pane (1) where necessary.