GB2074434A

GB2074434A - A baker's oven

Info

Publication number: GB2074434A
Application number: GB8013835A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-04-25
Filing date: 1980-04-25
Publication date: 1981-11-04
Also published as: GB2074434B

Abstract

A baker's oven has a substantially cylindrical casing divided by decks into a number of superimposed similar compartments, each with its loading doorway, door, and individually controlled electrical heating elements, a vertical driven shaft through the casing having mounted on it, in each compartment, a support for articles to be baked, extending outwardly from a central insulated core in the compartment.

Description

SPECIFICATION A baker's oven This invention relates to a baker's oven.

A commonly used type of baker's oven is of travelling oil or gas fired type, having an endless conveyor for support racks on which tins for bread or other bakery products are carried, the baking process being completed between the loading of the products, and their unloading after completion of a circuit within the oven. An oven of this type is large and expensive to manufacture, and it has the disadvantages that the vibration of the conveying system, and also the use of fans to promote even heat distribution within the oven, has adverse effects on certain bakery products. Moreover, such an oven is not, of course, suited to the simultaneous baking of products which have different baking requirements.

It has been proposed to provide multi-deck ovens, each deck with its own baking control, but these have not been generally satisfactory.

The general object of the present invention is to provide a baker's oven in which a variety of kinds of products with different baking requirements may be very satisfactorily baked simultaneously. Other objects achievable in preferred embodiments of the invention are to provide such an oven which is of particularly compact, simple and economical construction, which has low operating and maintenance costs, and which is very easy and convenient to load and unload.

With the foregoing and other objects in view, the baker's oven of the present invention has a casing, which may be substantially of upright cylindrical form, divided into a number of superimposed substantially cylindrical compartments, each with an individual loading doorway through the casing, and with individual controllable heating means. In each compartment, a rotatable support for articles to be baked is all being mounted on a common driven shaft, and in each compartment is a central heatinsulated central core, the articles to be baked being loaded on the support about the core.

A preferred embodiment of the invention is shown in the accompanying drawings, wherein: FIG. 1 is a perspective view of a baker's oven according to the invention, FIG. 2 is a cross-sectional view of the oven, and FIG. 3 is a sectional view of the lower part of the oven taken along line 3-3 in FIG. 2.

The baker's oven shown in the drawings includes a casing 10 of which the greater part is in the form of a cylindrical segment. The vertical front of the oven, however, is substantially flat, and the front parts of the sides ofthe casing are tangential and forwardly convergent to the sides of this flat section. The upright wall of the casing 10 is of insulated doubleskin construction, with an inner skin 11 and an outer skin 12, and an interposed insulating layer 13 of any suitable material.The top 14 and bottom 15 of the casing are also of insulated double-skin construction, as also are horizontal decks 16 mounted within the casing and dividing it into a number of similar compartments 17, each of the top, the bottom and the decks consisting of upper and lower sheet metal discs 18 and 19 welded to interposed substantially radial members (not shown) and with insulating material 20 between the discs.

The front of the casing 10 is formed with a series of doorways 21, one above the other, each leading into one of the compartments 17, and for each of the doorways there is provided an oven door 22, each with a handle or handles 23. The uppermost door is hinged at the top and counter balanced by a springloading device 24, the other doors being hinged at the bottom, their handles 23 serving as stops to limit their hinged movement below about horizontal. Any suitable catches (not shown) are provided for holding the doors in closed position. Each of the doors has a transparent window 25 set in an insulated hollow frame, and in each of the doorways 21 a door seal 26 of asbestos or like material is mounted.

Instrument panels 27 at the front of the casing 10, flanking the arrangement of doors one above the other, carry the necessary electrical switch gear and controls for the oven, and access doors 28 are provided to facilitate maintenance of the electrical equipment.

A main drive shaft 29 passes axially through the casing 10 and the compartments 17 and decks 16, being rotatable in a top bearing (not shown) on the casing top 14, and in a thrust bearing 30 mounted below the casing bottom 15. Above the casing top 14, the shaft 29 is fitted with a large pulley wheel 31 belt driven from a power unit 32, including an elec- tric motor and gear box, mounted on the casing top.

In each of the compartments 17, a support tray assembly 33 is fixed on the drive shaft 29. Each of these assemblies includes a central cylindrical core 34 of sheet metal with sturdy internal reinforcements (not shown), packed with heat-insulating material 35 and fixed coaxially on the shaft 29, a number of equally spaced arms 36 radiating from the lower part of the core being secured at their outer ends to a rim 37 and supporting an annular tray 38 of metal mesh disposed between the core and the rim. The core 34 extends almost fully from top to bottom of its compartment, and the rim 37 closely approaches the inner skin 11 ofthecasing 10.

Each of the oven compartments 17 is individually heated by thermostatically controlled heating elements, comprising a series of lower heating elements 39 and a series of upper heating elements 40.

Each of the heating elements is of well-known tubeencased type, with a small-radius U-bend between two substantially parallel adjacent parts which together are curved to a section of a spiral and are secured by clip 41, the lower heating elements 39 being mounted a short distance above the lower deck of the compartment, the upper heating elements being mounted a short distance below the upper deck of the compartment. Preferably the upper heating elements 40 are of somewhat lower wattage, and are fewer in number, than the lower heating elements 39.

In use, the heating elements are operated to bring each of the oven compartments 17 to its predetermined thermostatically controlled temperature, and the power unit 32 is operated to cause the support tray assemblies 33 to be rotated at a predetermined speed. Each ofthe compartments may be loaded with conventional baking tins for loaves, cakes or the like and/or with sheet metal trays on which small articles to be baked are placed. The dimensions of the core 34 and of the mesh tray 38 are such that a considerable number of the rectangular bread bak ing tins (not shown) may be supported radially on the tray, their inner ends near to the core, their outer ends near to the rim 37. The tins, then, will be well spaced apart except at their inner ends, and therefore there will be a good circulation of heated air between succeeding tins and even baking of their contents.Moreover, the removal of tins at the conclusion of baking is very easy, convenient and safe, as the outer ends of the radially arranged tins will be spaced from each other, and each may be easily grasped and withdrawn. No tins need be loaded in front of others, as in a conventional baker's oven.

The spiral arrangement of the upper and lower elec- tric heating elements is such that the outer part of a radially placed baking tin will receive substantially the same amount of radiated heat as the relatively slow-moving inner part of the tin. Little pre-heating of any compartment will be required before commencement of baking, much of the unused volume of the oven compartment 12 being occupied by the insulated cores 34, and good heat distribution being achieved without the use of a fan or blower. An oven according to the invention is particularly economical of space, and may occupy no more than about half the floor space of a conventional oven of similar baking capacity. The oven may be mounted on castor wheels as indicated at 42 to that it may be readily moved for thorough cleaning of a bakehouse or for other reasons.

An oven according to the invention may have, for example, two or three compartments instead of the four shown in FIG. and such a smaller capacity oven may be easily and economically enlarged by superimposing it on a supplementary one compartment or two compartment unit. For this purpose, the main drive shaft 29 may, as shown in FIG. 3, include a bottom end-piece 43, which is rotatable in the thrust bearing 30, removably engaged in the tubular main part of the shaft, a pin and slot device as indicated at 44 preventing relative rotation of the two parts.To add an extra compartment to the bottom of the oven, it is then necessary only to remove the thrust bearing 30 and replace it on the bottom of the supplementary unit, and to lengthen the drive shaft 29 by interposing between the main part of the drive shaft and its bottom end-piece 43 and appropriate lengthening piece (not shown) made for engage ment with the pins of the bottom end-piece and the slots of the main part of the drive shaft.

Baker's ovens according to the invention will be found to be very effective in achieving the objects for which they have been devised. It will, of course, be understood that the particular embodiment of the invention herein described and illustrated may be subjected to many modifications of constructional detail and design, which will be readily apparent to persons skilled in the art, without departing from the scope and ambit ofthe invention hereinafter

Claims

claimed. CLAIMS

1. A baker's oven including: a casing, a loading doorway in the casing, a support, rotatable about a substantially vertical, axis, within the casing, for supporting articles to be baked, heating means within the casing, and means for rotating the support.

2. A baker's oven including: a casing, a plurality of compartments, one above the other, within the casing, each two separated by a substantially horizontal deck, a loading dootwayin the casing for each of the compartments,.

a substantiallthorizontal support for articles to be baked rotatable in-eacts of the compartments about a substantially vertical axis, a core member in each compartment disposed about the axis of rotation ofthe support, heating means in each of the compartments, and means for simultaneously rotating the supports.

3. A baker's oven according to Claim 2 wherein: each compartment is substantially of vertical cylindrical form, and the core of each compartment is substantially circular in cross-section and coaxial with the compartment.

4. A baker's oven substantially as herein described with reference to the accompanying drawings.

4. A baker's oven according to Claim 3 wherein: the support includes an annular mesh tray secured to and extending outwardly from the lower part of the core.

5. A baker's oven according to either of Claims 2 to 2 wherein: the heating means includes electrical heating elements mounted above the bottom, and below the top, of each of the compartments.

6. A baker's oven according to Claim 5 wherein: the heating elements.are substantially horizontal and each is substantially in the form of a section of a spiral, those mounted above the bottom, and also those mounted below the top, of each compartment being in equally spaced arrangement.

7. A baker's oven according to any of Claims 2 to 6 wherein: all of the supports are mounted on a common substantiallyverticalshaft.

8. A baker's eveasubstantially as herein described with reference to the accompanying draw ings.

New daims fited on 5/3/81 superseded claims 1-8.

New or amended claims:- CLAIMS

1. Abaker'soven including: a casing, its interior of substantially vertical cylindrical form, a plurality of spaced horizontal heat-insulating decks fixed within the casing to divide it into a plural ity of superimposed substantially cylindrical com partments, loading doorways in the casing, one leading into each compartment, a shaft passing substantially axially through the compartments, a perforated substantially horizontal and circular support for articles to be baked within each compartment, secured coaxially on the shaft, a substantially cylindrical heat-insulating core within each compartment, disposed coaxially about the shaft and extending upwardly from the support to a position close to the top of the compartment, lower electric heating elements mounted on the bottom of each compartment, below the support, and upper electric heating elements mounted under the top of each compartment, and means for driving the shaft to rotate simultaneously the supports in the several compartments.

2. A baker's oven according to Claim 1 wherein: the support for articles to be baked is an annular mesh member secured to and extending outwardly from the lower part of the heat-insulating core.

3. A baker's oven according to either of the preceding claims wherein: the electric heating elements are substantially horizontal and each is substantially in the form of a spiral, the lower elements, and also the upper elements, being in substantially equally spaced arrangement and convergent towards the middle of the compartment.