CA1144818A - Baker's oven - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A baker's oven has its casing divided by horizontal decks into a number of superimposed substant-ially cylindrical compartments, a loading doorway leading into each. A vertical drive shaft through the casing carries, in each compartment, a central substantially cylindrical insulated core from the lower part of which extends an annular rotating support for articles to be baked, each compartment being individually heated electrically.
Each or any compartment may have an annular horizontal lid about the core, means being provided for lowering the lid onto bread tins on the support or lifting it clear above the tins.

Description

BACKGRO~ND OF T~IE: INVEN*ION
This invention relates t.o a baker's oven.
A commonly used type of baker's oven is Or travelling oi.'l or gas ei red type, having an endless conveyor for support racks on which tins for breaci or other bakery products are carried, the baking process beinK completed between the loading oi' the products, and their unloading after completion O-e a circui.t within the oven. An oven oi' 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 :eans to promote even heat distributi.on within the oven, has adverse ef-eects on certain bakery products. Moreover, such an oven is not, of collrse, suited to the simultaneous baking Oe products which have dief'erent baking requirements. Dev:ices eo:r ].idding bread tins for the baking of sandwich 10aVeS have been complicated and expensive in such ovens.
The general. object of -the present invention is to provide a baker's oven in which a variety of kinds of products with diF-eerent baking requirements may be very satis~actori1y baked sirnu]taneously. Other ob,jects achiev-able in pref'erred embodiments o~' the invention are to provide such an oven which incorporates very simple a.nd e-eeective liddin~ means for bread tins, is Oe particula.rly compact, simpl.e and econom:ical construc-tion, which has low (~perating .~b 41~

and maintenance costs, and which is very easy and convenient to load and unload.
In accordance with the broad concept of one aspect of the invention, there is provided and claimed herein a baker's oven comprising: a casing div:ided into a plurali-ty of superimposed compartments, a loading door leading into each of the compartments; a substantially horizontal support for articles to be baked in each compartment rotatable about a subs-tantially vertical axis; heating means in each compar-tment;
and means for simultaneously ro-tating the supports, the improvement comprising substantially horizontal heat insulating decks separa-ting the compartments and a substantially cylindrical heat insulating core in each compartment disposed coaxially about the vertical axis and extending upwardly from the support to a position close -to the -top of the compartment.
In a preferred embodiment, the interior of -the casing is of subs-tantially vertical cylindrical form, a substantially vertical shaft passing substantially coaxially through the compartments, and the supports are mounted on the shaf-t -to rotate simultaneously with the shaft.
Preferably, the heat insulating decks are peri-pherally connected to the casing and are centrally closely engaged about the shaft, and said core is disposed coaxially about the shaft and rotating with the support.
Other features and objects o the invention will be gathered from the following description of a preferred embodimen-t having reEerence to the accompanying drawings, wherein:
Fig. 1 is a perspective view of a baker's oven 83L~

according to the invention, FIG. 2 is a cross-sectional view of the oven along line 2-2 in FIG. 2, FIG. 3 is a sectional vi.ew ol the botto~ part o~ the oven along line 3-3 in FIG. 2, FIG. 4 is a sicle view o:~ the oven with an access door opened, and FIG. 5 is a s.ectional view along line 5-5 in FIG. 4.
DETAILED DESCRIPTION OF l'HE PRE~ERRED EMBODIMENT
.
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 15 of -the casing also being Or insul.ated double-wall construct~on, as al?~o are horizontal decks lfi mounted within -the casing and dividtng it i.n-to superimposed similar cc~mpart-ments 17.
The outer wall 12 has a ~lat -~ront through which doorways lead individually into the compar-tments 17, each .

doorway being provided with a door 18 wi1;h a transparent ~ t s~n window 19. Individual control panelsJ~3 are provided for -the oven compartments 17.
A main drive sha.ft 21 passes axially -througtl -the oven top 14, declcs 16 and bo-ttom 15, and is rotatable by any suitable power uni-t in a bearing 22a in the oven -top and ., .~

~4~

-in a thrust bearing 22b in the oven l)ottom In each compartment 17 a support -tray assembly 23 is fixed on the drive shaft, each assembly including a central. cylindrical core 24 of shee-t metal internally reinforced and packed with heat insula-ting ma-te~ial, a series of arrns 25 radiating :Erom the core bottom to a rim 26 supporting an annular mesh -tray 27. Each oven compartment 17 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 p:rovided with such means in each Or its four compartments. In each compar-tment an annular lid 30 is ~itted about the core 2~, being made ne a nurnber of siml:lar 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 o e -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 a-t 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 Oe the pair is fixed, by an I,-shaped bracket 36, to a tubular sleeve 37 rotatable on the sbaf-t 34 between its bearings 35, -the two lidding levers 33 being arranged so that each may be moved withont fouling -the other.
At opposite si.des of the oven, upwardly extending lever arms 38 fixed to the shaft 34 are pivotally connected to the upper ends o~ corresponding connecting rods 39. Also, at opposite sides of the oven, the bracket 36, and a lever arm 40 which is a:lso secured to the tubular sleeve 37, are pivotally connected -to the upper ends O e corresponding connecting rods 41. All o~ the connecting rods are ad~ustable by ~eans o.f turnbuckles 42.
At opposite sides of the oven, corresponding connecting rods 39 and 42 are connec-ted to the middle parts o~ a pair of horizon-tal li~ting arms 43 which are shaped to conform to the curvature o~ the oven wall; each li~ting arm being centrally fixed to a sleeve 44 slidable on a vertical rod 45. From the ends o~ each li~ting arm 43, two li~ting ~ingers 46 pass through ver-tical slot-like open.ings in the oven wall and, within -the oven compartment 17, are back-swept or angled towards the direction of rota-tion o:t the s~lpport tray assemblies.

In use, the hea-ting elements 28 and 29 are operated to bring each of the oven compartments -to its predetermined thermostatically control:led temperature, and the main drive shaf-t 21 is driven to cause -the support tray assemblies 23 to be rotated at a predeter-mined speed. Each o~ 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, wlll be well spaced apart except at their inner ends, and therefore there w:ill be good circul-ation o~ heated air between the tins and even baking of theircontents, Moreover, the removal of the tins at the conclu~ion : of baking will be ~acilitated by this spacing, and no tins need to be loaded in front of others.
When it is required that the bread tins o~ 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 and 41 descend and with them the two li.f-ting arms 43 and the lid 30, previously held stationary with:in the upper part o~ the compartment. When the lid is

2~ lowered onto the baking tins, its rollers 31 are brought down onto the sleeve 32 abou~ t.h(' cole 24, so the licl is caused to -turn with the rotating core. To raise the l:id 30, the appropriate lidding lever 33 is swung up, -to bring the lever arms 38, or the bracket 36 ancl lever arm 40, beyoncl "dead centre" posi.tions, so the lid 30 is l.i:fted to, ancl retained in, raised pos-ition.
It will be found t;hat t.lle spiral arrangemen-t Or the heating elements ensures even heatin~ of the produc-ts being baked and, most o~ the unused space o:f each oven compartment being occupied by tne i.nslll.ated core 2~, li-ttle pre-heating oi any compartment will be requi.red before commencing baking. The oven, althou~h very economical of space, may be used to bake a varie-ty Or products a-t the same time, at different temperat:ures i~ required.
An oven according -to the invention may have two or three compartments instead Or t:he four ill.ustrated, and may : be readily enlarged by superimposing it on a supplementary one-compartment or two-compartmen-t unit. For this purpose, -the main drive shaft 21 may includl? a bottom end-piece 46 rotatable in the thrust bea.ring 22b and rernovably engaged in the tubular main part of the drive shaft, a pln and slot device ihdicated at 47 prevent.ing relative rotati.on of the two parts. To a.dd an e~tra compa.r-tment at the bottom ol! the oven, it is then necessary only to remove the thrust bearing 22b and replace i.t on -t.he bottom of the .supplemellta2y unit, ~}~

-and to lengthen the d:rive slla:it by interpos-ing an appropria-te leng-thening piece between the main part o:~ the drive shaft and its end-piece 46.

Claims (7)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A baker's oven comprising:
a casing divided into a plurality of super-imposed compartments, a loading door leading into each of the compartments;
a substantially horizontal support for articles to be baked in each compartment rotatable about a substantially vertical axis;
heating means in each compartment; and means for simultaneously rotating the supports, the improvement comprising substantially horizontal heat insulating decks separating the compartments and a substant-ially cylindrical heat insulating core in each compartment disposed coaxially about the vertical axis and extending upwardly from the support to a position close to the top of the compartment.

2. A baker's oven as claimed in claim 1, wherein the interior of the casing is of substantially vertical cylindrical form, a substantially vertical shaft passing substantially coaxially through the compartments, and the supports are mounted on the shaft to rotate simultaneously with the shaft.

3. A baker's oven as claimed in claim 2 wherein the heat insulating decks are peripherally connected to the casing and are centrally closely engaged about the shaft, and said core is disposed coaxially about the shaft and rotating with the support.

4. A baker's oven as defined in claim 3, wherein said heating means of each compartment includes lower electrical heating elements on the bottom of said compartment below said support and upper electrical heating elements under the top of said compartment, each heating element being substantially of horizontal spiral form, both said lower elements and said upper elements being substantially equally spaced apart and being convergent toward the center of said compartment.

5. A baker's oven as defined in claim 3, wherein there is provided at least in one of said compartments an annular lid extending substantially horizontally outwardly from said core, and lifting means for moving said lid vertically in parallelism to lower it onto or raise it from articles to be baked.

6. A baker's oven as defined in claim 5, and means for automatically engaging said lid with said core to rotate therewith when said lid is in a lowered position and for freeing said lid from said core when it is in its raised position.

7. A baker's oven as defined in claim 5, wherein said lifting means includes fingers entering the sides of said compartment and supporting said lid, and means for simultaneously raising and lowering said fingers.