GB2079128A - A baker's oven - Google Patents

Abstract

A baker's oven having a rotary horizontal support for bread tins or the like is provided with a lidding device consisting of an annular horizontal lid rotatable coaxially with the support and means for raising and lowering the lid in parallelism to raise it to an inoperative position above and clear of the tins, or bring it down on top of the tins to rotate with them as the support is rotated.

Description

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

The specification of my co-pending patent application No. 50939/79 describes and illustrates a baker's oven of novel and improved construction in which there are a number of superimposed ovens within the one casing, a vertical shaft through the casing supporting, within each oven, a circular mesh tray and a central cylindrical insulated core, articles to be baked being placed on the annular mesh support about the core, each of the oven compartments being individually heated by top and bottom electric heating elements which are thermostatically controlled.

The object of the present invention is to provide a baker's oven of this general type having particularly simple and economical lidding means by means of which bread tins may be lidded or not, as may from time to time be required.

Accordingly, the invention resides broadly in a baker's oven of the type having an oven compartment, a horizontal support mounted rotatably about a vertical axis within the compartment, a doorway to the compartment for loading bread tins or the like on the support, and means for heating the compartment, wherein there is provided within the compartment a lid above and substantially coaxial with the support and means are provided for moving the lid vertically in parallelism to lower it onto bread tins or the like on the support or lifting it to a raised inoperative position.

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 along line 2-2 in Fig. 3, FIG. 3 is a sectional view of the bottom part of the oven along line 3-3 in Fig. 2, FIG. 4 is a side view of the oven with an access door opened, and FIG. 5 is a sectional view along line 5-5 in Fig. 4.

The oven illustrated includes a casing 10 with a substantially cylindrical inner wall 11, an outer wall 12 and interposed insulating material 13, the top 14 and bottom 1 5 of the casing also being of insulated double-wall construction, as also are horizontal decks 1 6 mounted within the casing and dividing it into superimposed similar compartments 1 7.

The outer wall 12 has a flat front through which doorways lead individually into the compartments 17, each doorway being provided with a door 18 with a transparent window 1 9. Individual control panels 20 are provided for the oven compartments 1 7.

A main drive shaft 21 passes axially through the oven top 14, decks 1 6 and bottom 15, and is rotatable by any suitable power unit in a bearing (not shown) in the oven top and a thrust bearing 22 in the oven bottom. In each compartment 1 7 a support tray assembly 23 is fixed on the drive shaft, each assembly including a central cylindrical core 24 of sheet metal internally reinforced and packed with heat insulating material, a series of arms 25 radiating from the core bottom to a rim 26 supporting an annular mesh tray 27. Each oven compartment 1 7 is individually heated by thermostatically controlled lower heating elements 28 and upper heating elements 29, each being doubled and shaped to spiral section form.

Any one or more of the oven compartments 17 may be provided with lidding means according to the invention, the oven illustrated being provided with such means in each of its four compartments.

In each compartment an annular lid 30 is fitted about the core 24, being made of a number of similar flanged sectors bolted together. To facilitate the raising and lowering of the lid in parallelism, a number of rollers 31 are mounted under the inside periphery of the annular lid. When the lid is lowered, these rollers engage a sleeve 32 about the lower part of the core 24, and when the lid is raised there is some clearance between the rollers and the core. The outside periphery of the lid closely approaches the inner wall 11 of the oven.

Each of the lids 30 of the oven may be individually raised and lowered by a lidding lever 33, the four levers being mounted in pairs, one pair of each side of the oven. In each pair, one lever is secured to an end of a shaft 34 rotatable in bearings 35 on the oven casing top 14, and the other lever of the pair is fixed, by an L-shaped bracket 36, to a tubular sleeve 37 rotatable on the shaft 34 between its bearings 35, the two lidding levers 33 being arranged so that each may be moved without fouling the other At opposite sides of the oven, upwardly extending lever arms 38 fixed to the shaft 34 are pivotally connected to the upper ends of corresponding connecting rods 39.Also, at opposite sides of the oven, the bracket 36, and a lever arm 40 which is also secured to the tubular sleeve 37, are pivotally connected to the upper ends of corresponding connecting rods 41. All of the connecting rods are adjustable by means of turnbuckles 42.

At opposite sides of the oven, corresponding connecting rods 39 or 41 are connected to the middle parts of a pair of horizontal lifting arms 43 which are shaped to conform to the curvature of the oven wall; each lifting arm being centrally fixed to a sleeve 44 slidable on a vertical rod 45.

From the ends of each lifting arm 43, two lifting fingers 46 pass through vertical slot-like openings in the oven wall and, within the oven compartment 17, are back-swept or angled towards the direction of rotation of the support tray assemblies.

In use, the heating elements 28 and 29 are operated to bring each of the oven compartments to its predetermined thermostatically controlled temperature, and the main drive shaft 21 is driven to cause the support tray assemblies 23 to be rotated at a predetermined speed. Each of the compartments 17 may be loaded with conventional baking tins for loaves, cakes or other bakery products and/or with sheet metal trays on which articles to be baked -are placed. The dimensions of the core 24 and of the mesh tray 27 are such that a considerable number of rectangular bread baking tins (not shown) may be supported radially on the tray, their inner ends near to the core, their outer ends near to the rim 26. The tins, then, will be well spaced apart except at their inner ends, and therefore there will be good circulation of heated air between the tins and even baking of their contents.Moreover, the removal of the tins at the conclusion of baking will be facilitated by this spacing, and no tins need to be loaded in front of others.

When it is required that the bread tins of any oven compartment should be lidded for the production of sandwich loaves, the appropriate lidding lever 33 is swung down so that its two connecting rods 39 or 41 descend and with them the two lifting arms 43 and the lid 30, previously held stationary within the upper part of the compartment. When the lid is lowered onto the baking tins, its rollers 31 are brought down onto the sleeve 32 about the core 24, so the lid is caused to turn with the rotating core. To raise the lid 30, the appropriate lidding lever 33 is swung up, to bring the lever arms 38, or the bracket 36 and lever arm 40, beyond "dead centre" positions, so the lid 30 is lifted to, and retained in, raised position.

It will be found that the spiral arrangement of the heating elements ensures even heating of the products being baked and, most of the unused space of each oven compartment being occupied by the insulated core 24, little pre-heating of any compartment will be required before commencing baking. The oven, although very economical of space, may be used to bake a variety of products at the same time, at different temperatures if required.

An oven according to the invention may have two or three compartments instead of the four illustrated, and may be readily enlarged by superimposing it on a supplementary onecompartment or two-compartment unit. For this purpose, the main drive shaft 21 may include a bottom end-piece 46 rotatable in the thrust bearing 22 and removably engaged in the tubular main part of the drive shaft, a pin and slot device indicated at 47 preventing relative rotation of the two parts. To add an extra compartment at the bottom of the oven, it is then necessary only to remove the thrust bearing 22 and replace it on the bottom of the supplementary unit, and to lengthen the drive shaft by interposing an appropriate lengthening piece between the main part of the drive shaft and its end-piece 46.

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 herein described and illustrated may be subject to many modifications of constructional detail and design, which will be readily apparent to persons skilled in the art, without departing from the scope of the invention hereinafter claimed.

Claims (7)

1. A baker's oven of the type having an oven compartment, a horizontal support mounted rotatably about a vertical axis within the compartment, a doorway to the compartment for loading bread tins or the like on the support, and means for heating the compartment, wherein: there is provided within the compartment a lid above and substantially coaxial with the support, and means are provided for moving the lid vertically in parallelism to lower it onto bread tins or the like on the support or lifting it to a raised inoperative position.

2. A baker's oven according to Claim 1 wherein: the support is annular, extending outwardly from the lower part of a substantially cylindrical coaxial core, and the lid is a substantially horizontal annular member about, and extending outwardly from, the core.

3. A baker's oven according to Claim 2 wherein: means are provided for automatically engaging the lid with the core, for rotation therewith, when the lid is in its lowered position, and for freeing the lid from the core when it is in its raised position.

4. A baker's oven according to any one of the preceding claims wherein: the means for moving the lid vertically include fingers entering the sides of the compartment and supporting the lid, and means for simultaneously raising or lowering the fingers.

5. A baker's oven according to Claim 4 wherein: the fingers comprise two pairs at opposite sides of the compartment, those of each pair being interconnected by a vertically slidable arm, and a manually operable lever and link assembly is mounted on the oven for simultaneously raising and lowering the vertically slidable arms of both pairs of fingers.

6. A baker's oven according to any one of the preceding claims wherein: the means for heating the compartment comprise thermostatically controlled electric heating elements, mounted on the bottom of the compartment below the support, and under the top of the compartment above the lid.

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