US2593273A - Baking oven - Google Patents

Description

April 1952 E. M. CROSLAND 2,593,273

BAKING OVEN Filed Feb. 15, 1948 2 SHEE'I SSHEET l April 15, 1952 E, M. CROSLAND 2,593,273

BAKING OVEN Filed Feb. 13, 1948 2 SHEETS-SHEET 2.

Patented Apr. 15, 1952 BAKING OVEN Edward Milner Crosland, Culcheth, near Warrington, England, assignor to T. & T. Vicars Limited, Earlestown, Newton-le-Willows, England, a British company Application February 13, 1948, Serial N 0. 8,225

In Great Britain July 13, 1 939 Section 1, Public Law 690, August 8, 1946 Patent expires July 13, 1959 l The present invention relates to baking ovens and in particular to ovens of the type wherein baking is effected by the passage of the goods,

such as biscuits for example, through a baking chamber when supported on a travelling steel band, which may be solid, perforated or of reticulate form such as of wire mesh, and wherein the heating medium may be gas or oil, or may. be constituted by electric elements.

Usually for the purpose of baking articles, such as biscuits, they are placed automatically on to the band by the forming machine or mechanism associated therewith, the arrangement of the articles on the band being such that a small margin is left between the longitudinal side edges of the band and the outer side edges of the band and the outer side edges of the laterally outermost biscuits. Again, as the band in its passage longitudinally through the oven is liable to wander laterally to a limited extent, it is necessary for the oven chamber to be wider than the steel band by an amount of approximately several inches in order to prevent contact between the side edges of the band and the sides of the oven. The oven chamber in vertical cross section may be considered as being in three parts, top heating section, baking section, and bottom heating section. These sections may be separated from one another by means of partitions formed either of, solid material such as sheet iron or perforated material. One section only may be partitioned off or both partitions may be omitted. When the oven chamber including the three sections is in the form of a rectangular chamber with straight sides, then it will be appreciated that the heating chambers are wider than the goods on the band passing through the oven and as a direct result the side biscuits on said band are liable to be more highly coloured than the others.

An oven is known in which a series of plates attachedto a chain to form a travelling hearth, which has rollers running in guides in a portion of the oven which is wider than the oven above the-said travelling hearth. In band ovens there is a particular tendency for the band to wander sideways.

The object of the present invention is to overcome the above mentioned disadvantages and accordingly by the present invention the lateral width of the conveyor band is greater than the width of the oven at positions above it, the oven being wider in the regions of the substantially horizontalplane of traverse of the conveyor band to accommodate the said conveyor band together '3 Claims. (01. 107-55) with those goods disposed at the side edges of the conveyor band. Preferably'the lateral width of the conveyor band is also greater than th width of the oven at positions below it.

This is accomplished by providing channels in theside walls of the oven to accommodate the longitudinal edges of the band.

Where it is desired to divide the oven vertically into chambers with a baking chamber between upper and lower heating'chambers isolated therefrom either the .whole or a part of the baking chamber, considered vertically, may be of greater width than the heatin chambers. The invention is more particularly described with reference to the accompanying drawings, in which: 1 t a Figure l is a longitudinal section through an oven constructed according to the present inveiition, the section being taken over part of the length only of the oven.

Figure 2 is a corresponding transverse section taken on the line 2--2 of Figure l. I

In the construction according to the drawings, an endless band ill for the reception-of biscuits or thelike to be baked, has a substantially horizontal plane of traverse in one direction through the oven where it is supported on skids H, and travels in the returndirection-below the oven where its supporting means are not shown, The oven is divided into three compartments, namely a baking chamber l2, an upper heating chamber l3 and a lower heating chamber M, the chambers I3 and 14 containing heating means in the form of rail type gas burners I5, l6, adapted respectively to provide means for supplying top and bottom heat to the baking chamber I2 and the goods travelling therethrough. The base of the lower heating chamber 14 is constructed by tiles ll which are supported on inverted T iron bearers 18. Similarly the roof of the upper heating chamber is constituted by tiles I 9.

In the construction illustrated the baking chamber 12 is isolated from the top and bottom heating chamber l3, l4, respectively by plates 20, 2|, the former of which are provided with fins 22, the depth of which increases gradually longitudinally of the oven as the height above the plate 2| of each longitudinal section of a baking chamber roof constituted by a plate 20 increases (Fig. 1). The sides of the oven constituted by the upper and lower heating chambers and the baking chamber are shown at 23 and are constructed from sheet iron onother comparatively thin material. The opposite sides 23 are separated by a width substantially equal to that width equal to that of the oven over the major portion of its height but it also enables a predetermined amount of lateral wander or play of the band. a

In order that the products of combustion of the burners It may escape from the lower heating chamber l4, holes 25 are provided at the base of said chamber which communicate with a flue 26 leading through; ducts 21 to an exhaust fan chamber 28.. Thereof 20 of the bakingchamber which, whilst providing top heat to the goods in the baking chamber prevents access thereto of the products of combustion from the upper burners l and is supported by cross bearers 29 in the form of tubes o fqrectangular section said tubes being perforated for otherwise apertu-red. and

less band conveyor on which the goods to be baked are carried through said chamber, the'sides of said chamber above and below the upper run of the conveyor being vertically aligned, longitudinal recesses in the side walls adjacent the upper run of the conveyor and into which the longitudinal edges of the upper run project, the upper edges of the recesses being spaced above the conveyor to provide a baking area for goods disposed at the edges of the upper run of the conveyor.

2. An oven having a baking chamber, a con-- veyor having an upper run on which the goods to shrouded by dampers 30 in the form of perfcrated plates to control the entrance intd'and passage through, the tubes of steam rising from the products in the baking chamber. The tubes communicate through ducts 3| with flues 32 at spaced intervals longitudinally of the oven. The prodnets of combustion of the upper burners [5 escape from the upper heating chamber l3 through longitudinally spaced gaps 33 between tiles [9 into chambers 34 which extend laterally of the oven, and thence through openings 35 in the roof 36 of said chambers 34 into the fan chamber 28.

It will be appreciated that by making the width of the baking chamber, at or adjacent the horizontal plane of'the band conveyor H], greater than the width of the baking chamber at other vertical positions, or greater than the heating chambers above and below it, a more even baking, with less tendency for the groups of biscuits to scorch at the side edges of the band conveyor, is eifected. V

The invention is equally applicable to ovens where either top or bottom heat only is applied to the goods on the conveyor band.

I declare that what I claim is:

1. An oven having a baking chamber, an endbe baked are carried through said chamber, the

- sides of said chamber above and below the upper run of the said conveyor being vertically aligned, longitudinal recesses in the side walls adjacent the upper run of the conveyor and into which the longitudinal edges of the conveyor project, the upper edges of the recesses being spaced above the conveyor to provide a baking area for goods disposed at the edges of the conveyor.

3. An oven having a baking chamber a conveyor having an upper run on which the goods to be baked are carried through the chamber, longitudinal recesses in the baking chamber side walls adjacent the upper run of the conveyor and being open throughout their length to the baking chamber and laterally enclosing said conveyor run, the upper walls of the recesses being spaced above the conveyor run thereby to provide a baking area for goods disposed at the edges of the'conveyor.

EDWARD MILNER CROSLAND.

- REFERENCES CITED The following references are of record in'the file of this patent:

UNITED STATES PATENTS Neutelings et al. Sept. 6, 1949

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