GB2145318A

GB2145318A - Arrangement in bakery ovens

Info

Publication number: GB2145318A
Application number: GB08417020A
Authority: GB
Inventors: Ingvar Petersson; Sven Roos
Original assignee: ANI MEKANISKA AB
Current assignee: ANI MEKANISKA AB
Priority date: 1983-07-05
Filing date: 1984-07-04
Publication date: 1985-03-27
Also published as: DK164433B; GB8417020D0; DK327584A; GB2145318B; DK164433C; SE449474B; SE8303832D0; DE3424447A1; DE3424447C2; SE8303832L; DK327584D0

Abstract

A tunnel type bakery oven 1 comprises an endless conveyor 2 for conveying loaves 5 from the entrance end 3 to the discharge end 4 of the oven. To provide a lateral support for the loaves so that they cannot flow out laterally, lateral supports 6 are disposed along the longitudinal edges of the conveyor. These lateral supports may be each composed of several hingedly interconnected supporting members 8 in the form of generally parallelepipedal sheet-metal boxes retained on the conveyor by magnetic forces. The box-like supporting members of each lateral support travel in an endless path through the oven together with the conveyor in the direction A from the entrance end 3 to the discharge end 4, whereupon the supporting members, via guide pulley structures and a conveyor belt or the like, travel back to the entrance end 3 in the direction B outside the oven. <IMAGE>

Description

SPECIFICATION Arrangement in bakery ovens The present invention relates to an arrangement in bakery ovens comprising an endless conveyor for conveying loaves of bread through the oven from the entrance end to the discharge end thereof, the longitudinal edges of the conveyor being provided with means for laterally supporting the loaves.

In the making of bread on an industrial scale in bakeries by means of baking ovens of the tunnel type, the loaves usually are placed side by side on a conveyor, made of steel wire netting, in rows lying transverse to the direction of travel and having a length substantially corresponding to the width of the oven, the loaves previously fermented in a fermentation chamber being baked according as they are conveyed through the oven.

When the fermented loaves enter the oven and are subjected to the oven heat, the outermost loaves tend to float out laterally. To prevent this, wooden battens are used which are placed on the conveyor along the longitudinal edges thereof to engage the outer sides of the outermost loaves.

The battens are detachably interconnected to form a continuous support along each longitudinal edge, the battens first being disposed on the conveyor at the entrance end of the oven and connected to the battens immediately before them, whereupon they are detached from the following battens at the discharge end of the oven and are transferred by hand to the entrance end for reconnection etc. this work is very time-consuming and complicated, and furthermore the battens do not last very long because they are gradually charred in the oven because of the high temperature therein.

To eliminate the problems associated with the use of wooden battens, bakeries have begun in the last few years to use supporting rails of elastic material, such as silicone rubber, which are fixedly mounted on the longitudinal edges of the conveyor. However, like the wooden battens, such elastic supporting rails suffer from the disadvantage that they are not proof against the heat in the oven and eventually become brittle and break.

It is the object of this invention to provide a novel type of lateral supports which do not suffer from the above-mentioned disadvantages and problems.

Moreover, it is the object of this invention to design the lateral supports in such a way that the outer side of the outermost loaves is insulated from the direct oven heat to avoid burning. In principle, the lateral supports thus are intended to function as "dummy" loaves having the same heat characteristics as the real loaves so that the outermost loaves will be fooled, so to speak.

These objects are achieved in that each lateral support is formed of several hingedly interconnected supporting members travelling in an endless path through the oven together with the conveyor from the entrance end to the discharge end and then, outside the oven, back to the entrance end, and that the supporting elements are carried along in the conveyor movement.

The invention will now be described, by way of example, reference being made to the accompanying drawing which is a schematic top plan view of a tunnel type bakery oven from which the roof has been removed and which is equipped with the arrangement according to the invention.

The bakery oven which is illustrated in the drawing and generally is designated 1 preferably is of the tunnel type for making bread on an industrial scale. The oven 1 comprises an endless conveyor 2 made of magnetic or magnetisable steel wire netting and travels over guide pulleys (not shown) at the entrance end 3 and the discharge end 4, respectively, of the oven 1. Fermented loaves 5 arriving from a fermentation chamber (not shown) are placed side by side on the conveyor 2 in rows which are transverse to the direction of travel A and of a length substantially corresponding to the width of the oven 1.

When the fermented loaves 5 enter the oven 1, the outermost loaves - as has been mentioned before - tend to flow out laterally, the prevention of which is one of the objects of this invention.

Thus, the two longitudinal edges of the conveyor 2 are provided with supports generally designated 6 for laterally supporting the loaves 5 by engaging the outer sides of the outermost loaves.

In the preferred embodiment illustrated, each lateral support 6 is formed of several supporting members 8 which are hingedly interconnected by means of more or less conventional hinges 7 and which are in the form of generally parallelepipedal sheet-metal boxes. The supporting members 8 comprised by each lateral support 6 travel in an endless path through the oven 1 together with the conveyor 2 in the direction A from the entrance end 3 to the discharge end 4 and then, via guide pulley structures 9 not shown in detail and a roller conveyor or the like (not shown), back to the entrance end 3 in the direction B outside the oven 1.

As has been mentioned before, the conveyor 2 is made of magnetic or magnetisable material, and in the illustrated embodiment of the invention the supporting members 8 are then provided with permanent magnets so that the supporting members 8 are carried along by the movement of the conveyor 2 under the action of the magnetic forces between the permanent magnets of the supporting members and the conveyor. The magnetic forces are so chosen that the supporting members 8, when they approach the guide pulley structure 9 at the discharge end 4, are disengaged from the conveyor 2 to be carried over the guide pulley structure 9. When, eventually, the supporting members 8 via the guide pulley structure 9 at the entrance end 3 of the oven 1 come into engagements with the conveyor 2, they are again attracted thereby to be conveyed through the oven, etc.

To form a smooth supporting surface against the loaves 5 during transport through the oven 1 for baking, each box-like supporting member 8 is provided at its rear end, as seen in the direction of travel A through the oven, with an overlapping flange 10 serving to overlap part of the supporting surface of the following supporting member 8.

According to an especially preferred embodiment of the invention, the box-like supporting members 8 are filled with a heat-resistant material, preferably mineral wool, which, before the supporting elements 8 enter the oven 1 at the entrance end 3, are wetted with water or some other suitable liquid which under the action of the oven heat evaporates therein in the form of steam, thereby to cool the supporting members to prevent burning of the outer sides of the outermost loaves 5. In principle, the supporting members 8 thus function as dummy loaves which are to have the same heat characteristics as the real loaves 5 so that the outermost loaves are fooled to believe that there are further loaves on the outer side.

In some cases, it may happen that the rows of loaves 5 on the conveyor 2 are of varying lengths, and in order to accomplish the desired lateral support of the loaves in spite of this variation, the guide pulley structures 9 at the entrance end 3 of the oven 1, and/or the frame portions or the like carrying these structures, may be made movable in the direction of the arrow C transversely of the direction of travel A of the conveyor 2. If necessary, also the guide pulley structures 9 at the discharge end 4 of the oven 1 may be movable in this or some similar manner.

If the conveyor is made of non-magnetic material, for instance a mat or a belt of plastics or the like, the magnetic forces adapted to retain the supporting members 8 on the conveyor may be accomplished by providing sheet-metal plates or the like of magnetic or magnetisable material underneath the upper part of the conveyor which are then attracted by the permanent magnets in the supporting members 8 with the upper part of the conveyor 2 therebetween.

The invention is, of course, not restricted to the embodiment illustrated and described above, but may be modified in several ways within the scope of the appended claims.

Claims

1. An arrangement in bakery ovens comprising an endless conveyor for conveying loaves of bread through the oven from the entrance end to the discharge end thereof, the longitudinal edges of the conveyor being provided with means for laterally supporting the loaves, characterised in that each lateral support is formed of several hingedly interconnected supporting members travelling in an endless path through the oven together with the conveyor from the entrance end to the discharge end and then, outside the oven, back to the entrance end, and that the supporting elements are carried along in the conveyor movement.

2. An arrangement as claimed in Claim 1, characterised in that the supporting members are carried along by frictional forces between the supporting members and the conveyor.

3. An arrangement as claimed in Claim 2, characterised in that the frictional forces are sustained by magnetic forces.

4. An arrangement as claimed in claim 2 or 3, characterised in that the conveyor is made of magnetic or magnetisable material, and that the supporting members are provided with permanent magnets attracting the conveyor, or vice versa.

5. An arrangement as claimed in claim 2 or 3, characterised in that the conveyor is made of nonmagnetic material, that plates or the like of magnetic or magnetisable material are provided underneath the upper part of the conveyor, and that the supporting members are provided with permanent magnets attracting said plates, or vice versa.

6. An arrangement as claimed in any one of the preceding claims, characterised in that the supporting members are in the form of generally parallelepipedal hollow sheet-metal boxes.

7. An arrangement as claimed in any one of the preceding claims, characterised in that the supporting members also form insulating members and are filled with a heat-resistant material which, before the supporting members enter the entrance end of the oven, can be wetted with water or other suitable liquid which, under the action of the heat in the oven, evaporates therein in the form of steam to cool the supporting members to prevent burning of the outer sides of the outermost loaves.

8. An arrangement as claimed in claim 7, characterised in that the heat-resistant material is mineral wool.

9. An arrangement as claimed in any one of the preceding claims, characterised in that the supporting members are provided at their rear end, as seen in the direction of travel through the oven, with an overlapping flange serving to overlap part of the supporting surface of the following supporting members to form a smooth supporting surface against the loaves during transport through the oven.

10. An arrangement as claimed in any one of the preceding claims, characterised in that the lateral supports are movable, at least at the entrance end of the oven, transversely of the direction of travel of the conveyor for adaptation to the number of loaves placed in side by side relationship.

11. An arrangement in bakery ovens substantially as herein described with reference to the accompanying drawing.