AU639333B2

AU639333B2 - Electrically heated rotary bakers' ovens

Info

Publication number: AU639333B2
Application number: AU77173/91A
Authority: AU
Inventors: Paul Eaton Willett
Original assignee: APV Baker Pty Ltd
Current assignee: Moffat Pty Ltd
Priority date: 1990-05-22
Filing date: 1991-05-20
Publication date: 1993-07-22
Anticipated expiration: 2011-05-20
Also published as: AU7717391A

Description

639333 1

AUSTRALIA

Patents Act 1990 I Name of Applicant Actual Inventor Address for Service APV BAKER PTY LTD PAUL EATON WILLETT GRANT ADAMS COMPANY, Patent Trade Mark Attorneys Level 9, National Mutual Centre, 144 Edward Street, BRISBANE. QLD. 4000

AUSTRALIA.

"ELECTRICALLY HEATED ROTARY BAKERS' OVENS" Invention Title Details of Associated Provisional Applications Numbers PK0278 The following statement is a full description of the invention including the best method of performing it known to me.

THIS INVENTION relates to electrically heated rotary bakers' ovens.

A well-known and widely used baker's oven has a number of superimposed oven compartments with individual oven doors at the front. A vertical drive shaft driven by an electric motor passes through all of the compartments. In each compartment, a sleeve is mounted on, and frictionally driven by, the shaft.

Fixed on each sleeve are two carrier frames, one spaced above the other, each frame carrying two grid supports, to opposite sides of the sleeve. Each support is capable of receiving through the opened oven door of the compartment, and when the carrier frames and sleeve have been brought temporarily to rest, two adjacent assemblies, each of three bread baking tins. Four such assemblies, or twelve of the baking tins, may thus be loaded on to the two carrier frames, and after the carrier frames have been permitted to turn through 180", a further four assemblies of the baking tins may be loaded similarly.

Bakery goods other than those in bread baking tins may, of course, be loaded into the oven in this way. When the baking has been completed, the baked articles may be easily and quickly unloaded.

The oven compartment is heated by electric heating elements of rod type, each shaped to form an elongated U, the parallel arms of which extend across S.the oven. One series of elements is at the bottom of the compartment, another at the top, the parallel arms of each element being housed in channels formed in the bottom and top plates of the oven compartment. A third set of heating elements is supported between the two carriers.

Although ovens of this type have been found to be very effective and generally satisfactory, a problem can exist when, as sometimes happens, there are undue delays during the unloading or loading of bakery products on the carriers at rest, when "hot spots" may cause over-baking.

The present invention has been devised to overcome or substantially reduce this problem by a novel arrangement of the heating elements of the oven as defined in the appended claims.

An exemplary embodiment of the invention is shown in the accompanying drawings, in which: FIG 1 is a diagrammatic representation of the floor plan of a compartment of a baker's oven according to the invention, being a sectional view taken along line 1-1 in: FIG 2, which is a sectional view of the oven compartment taken along line 2-2 in FIG 1.

The oven compartment illustrated has, formed from stainless steel sheet, a top 10, floor 11, back 12 and sides 13, which, near to the front, are convergent to a loading and unloading doorway 14 which may be closed by a glass hinged door indicated at 4 A vertical motor-driven drive shaft 16 passes more or less centrally through the compartment within which it is enclosed by a sleeve 17 normally rotated S frictionally by the drive shaft but capable of being held stationary by a first arm of a bell-crank (not shown) at one side of the doorway 14 and brought to operative position when the door 15 is opened to disengage the other arm of the bell-crank, the first arm, when in operative position, intercepting and interrupting the rotation of one or two carriers 18 mounted on the sleeve 17, one above the other. Each carrier includes a pair of box-section arms 19 radiating from the sleeve 17 and at their outer ends fixed centrally to a pair of parallel angle members 20 to the upright flanges of which parallel side plates 21 are secured, the horizontal flanges of the angle members supporting, to opposite sides of the sleeve 17, a pair of grid supports 22 for assemblies 23 of bread baking tins. Above each support 22 is a sheet metal lid 24 with wheels 25 travelling on tracks 26 on the side plates and so ramped that when a lid is advanced, it simultaneously rises and when retracted, it lowers onto the tops of the bread baking tins on the support 21.

The oven compartment is heated by three series of electric heating elements. One series of heating elements at the compartment floor comprises four elongated tube elements, each formed with a central Ubend, its parallel sides being housed in channels formed transversely across the floor 11, the U-bend part being bent upwardly to bridge the part of the floor between the two channels. The elements 27 are all similar, the centre of the parallel arms of each being spaced by, say 90mm. However, the elements are not spaced evenly apart. The front one of the elements is located in front of the shaft 16 by a distance of, say, 120mm from the shaft centre to the centre of the near arm of the element. The second element from the front of the oven Shas its front arm spaced from the centre of the shaft by, say, 25mm. The spacing between the second element and the third element is, say, 110mm, which is greater than that between the third and fourth elements which is The middle series of heating elements 28 is carried by support bars 29 so that the elements 28 are midway between the two carrier frames 18, and the arrangement of the heating elements 28 is similar to that of the heating elements 27.

The heating elements 30 of the compartment top consist of two similar elements of elongated U-shape, the parallel arms of which are more widely spaced at, say, 140mm, than those of the elements 26 and 27. The elements 30 are housed in inverted channels formed transversely of the compartment roof, one element being located in front of, the other behind, the shaft 16. The front one of these two elements is spaced by, say, 75mm from the shaft centre, the second element is spaced by, say, 145mm behind the shaft centre.

This arrangement of the heating elements is such that if the carriers 18 should be held at rest for some time and then, after being rotated through 1800, again held at rest, as will occur when the cariers are being loaded and unloaded with the bread baking tin assemblies, no part of the carrier or the tins carrier thereon will be directly over, or directly under, a heating element when the carrier is in both positions.

Consequently, there will be no likelihood of "hot spots" and over-baking occurring.

Bakers' ovens according to the invention will be found to be very effective in achieving the objects for which they have been devised. Various modifications may, of course, be made within the scope and ambit of the invention.

4 eeS S. S S Se

Claims

1. An electrically-heated rotary bakers' oven having at least one oven compartment of the type having at least one carrier on a vertical drive shaft, an oven door at the front of the compartment, and heated by at least one series of electric elements of the.rod type, each element shaped to form an elongate U, the parallel arms of which extend transversely across the oven, wherein: in the or each series of elements, the elements are unevenly spaced apart so that if the carrier is held at rest in a first position, and then rotated through 180° and held at rest at a second position, no one part of the carrier will be directly over, or directly under, the arms of the or each series of elements, in both positions.

2. An oven according to Claim 1 wherein a first series of elements has four elements at the compartment Sfloor, with a first element between the oven door and the drive shaft and second, third and fourth elements rearwardly of the drive shaft.

3. An oven according to Claim 2 wherein: the parallel arms of each element are spaced a distance A apart; 25 the first element is located in front of the drive shaft a distance greater than A between the drive shaft and the rear arm of the first element; and the second element is located rearwardly of the drive shaft a distance less than A between the drive 30 shaft and the front arm of the second element.

4. An oven according to Claim 3 wherein: the spacing between the adjacent arms of the second and third elements is greater than the distance A, which is the distance between the adjacent arms of the third and fourth elements.

An oven according to Claim 3 wherein: a second series of elements has two elements at the compartment top, the first element between the oven door and the drive shaft and the second element rearwardly of the drive shaft, the distance between the parallel arms of each element are spaced a distance greater than the distance A apart; and the parallel arms are not directly above the parallel arms of the elements in the first series.

6. An oven according to Claim 5 wherein: the compartment has two pairs of vertically- spaced carriers on the drive shaft; and a third series of elements is supported midway between the two pairs of carriers, the arrangement being similar to the arrangement of the elements in the first series.

7. An oven according to Claim 6 wherein: the elements of the third series are supported on support bars extending longitudinally of the compartment.

8. An oven according to any one of Claims 2 to 7 .wherein: the parallel arms of the elements of the first series are supported in channels transversely of a' the compartment floor. 25

9. An oven according to Claim 5 wherein: the parallel arms of the elements in the second series are housed in inverted channels transversely of the compartment roof.

10. An electrically-heated rotary baker's oven 30 substantially as hereinbefore described with reference to the accompanying drawings. DATED this thirtieth day of April 1993. APV BAKER PTY LTD, By their Patent Attorneys, S 35 GRANT ADAMS COMPANY. II, ABSTRACT A baker's oven has an oven compartment with a vertical drive shaft (16) supporting two pairs of carriers (18). The compartment is heated by electrical heating elements (27, 28, 30) each shaped to form an elongate U, with parallel arms extending across the compartment. The elements are arranged, by their respective spacing to the drive shaft and by their spacing in each series of elements (27, 28, 30) so that if the carriers (18) are held at rest for some time in a first position and then rotated through 180c and held at rest for the same time in a second position, no part of the carriers (18) will be directly over, or directly under, an arm of a heating element (27, 28, 30) in both positions, to thereby avoid the likelihood of "hot spots", or overbaking in the bakery products supported by the carriers (18).