AU608168B2 - Improvements in bakers' ovens - Google Patents

Description

608168 This document contains the amendments made -under Section 49 and is correct for printing.

COMMONWEALTH OF AUSTRALIA 0 00 0 0 0 a go o 0 o o 0 0 00 0 Patents Act 1952 Name of Applicant Address of Applicant Actual Inventor(s) Address for Service APV BAKER PTY LTD Cook Road, Mitcham, 3132, Australia Victoria, Paul Eaton WILLETT GRANT ADAMS COMPANY, Patent Trade Mark Attorneys, 333 Adelaide Street, BRISBANE. QUEENSLAND. 4000

AUSTRALIA.

0o 0 a 0 &o a 00 COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: "IMPROVEMENTS IN BAKERS' OVENS" The following statement is a full description of the invention including the best method of performing it known to the applicant.

B0r~0286 I 27/0)7/0M9 1 THIS INVENTION relates to improvements in bakers' ovens.

It is a common practice to introduce steam to a baker's oven during the baking of certain kinds of loaves and other bakery products to impart a glazed surface to the crust. This may be done by means of a separate or external steam generator which delivers the steam through a valve-controlled nozzle or jet.

It is also well-known to provide in an oven a metal block which is heated by the oven and into which water may be introduced under pressure to b converted into steam by the heated block and delivered through a ooo nozzle orifice.

C, 0 1 These devices have the disadvantage that in 15 areas where the water used is particularly hard, the no nozzles are likely to become quickly blocked by mineral 00° deposition.

0oo It is an object of the present invention to provide, for a baker's oven, novel and improved means for the quick and efficient introduction of steam without any likelihood of blockage, despite any degree oC 0 of hardness of the water used.

Do Oo: Other objects achieved in preferred oo embodiments of the invention are to provide for a Oo 25 baker's oven a steam generating device which is particularly simple and economical to mianufacture, and sturdy and durable in use.

the With the foregoing and other objects in view, C, the invention resides broadly in a steam generating means for a baker's oven including an assembly of heating plates, one above the other f lo..tion within and heated by the oven; ahrmeans for introducing water onto a top heating plate to cascade down to the lower heating plate or plates in sequence and, by heat transfer from the heating plates to be converted to steam within the oven. Preferably the assembly is hinged at an opening to the oven so it can be swung out for inspection or maintenance. The oven, in a preferred form, has an inner chamber within an outer casing with interposed insulation, a loading and unloading door being provided at the front of the oven, the oven being heated by electric heating elements housed within channels in the top and bottom of the oven, a driven turntable being provided within the inner chamber to carry bakery products to be baked. Preferably means are provided for bringing the turntable automatically to rest when the door is opened for loading or unloading.

Other features of the invention will become apparent o 04 from the following description.

oo a00 0 cs :An embodiment of the invention is shown, by 1 i5 way of illustrative example only, in the accompanying 0000 00 drawings, wherein:o 0 FIG. 1 is a sectional view of a baker's oven o o00 0 o 0 taken along line 1-1 in 0 FIG. 2, which is a partly broken-away sectional view taken along line 2-2 in FIG. 1, and FIG. 3 is a perspectiv view of one of the 0 o0 steam generating assemblies of the oven.

o0 oo The oven illustrated includes an oven chamber o C consisting of a top 11, bottom 12 and side walls 13, 9o. 25 all of which are preferably of sheet stainless steel, the top and bottom being formed with transverse channels 14, the ends of which are closed by the side walls 13.

cf The oven chamber 10 is housed within an outer casing insulating material 16 being interposed between the two.

A loading and unloading doorway 17, lined with sheet stainless steel, leads through the outer casing and into the oven chamber, and may be closed by a pair of doors i 18, one above the other. Each of these doors may be a panel of plate glass fixed between channelled metal ends fixed to brackets 19 which are pivoted to the sides of the doorway 17, the brackets at one side of the doorway being connected by links 20 so that, by means of a handle 21 on the upper door, both the doors may be swung down to closed positions, as shown in FIG. J, or up to horizontal open positions within the doorway, as shown in FIG. 2.

The oven is heated by bottom, central and top electric heating elements 22, each being of rod type formed with a middle U-bend. The top and bottom elements are except at their U-bends, housed in the channels 14 formed in the oven top 11 and bottom 12, the U-bent part of each being raised and carried around from one channel to the next. The heating elements are 0 oo releasably held in place by retaining rods 23. The ,o central heating elements are supported by horizontal rods (not shown in the drawings) fixed in the oven.

o o o- The oven can receive four baking trays (not 0O shown) loaded with bakery products, or eight assemblies of bread baking tins (not shown), inserted through the doorway 17 onto a turntable 25. This turntable is of two-deck type and it includes a central sleeve 26 which is rotatable on a vertical drive shaft 27 passing eeoo o centrally through the oven and driven by any suitable 0oo drive means from a motor (not shown). The turntable ordinarily rotates with the shaft, by reason of friction °o o ao 25 between the two, but it may be brought to rest without interrupting the drive to the shaft. Two pairs of opposed arms 28, one above the other, radiate from the o °L sleeve 26 and are fixed perpendicularly at their outer o ends to the middles of angle supports 29. These supports may carry baking trays to both sides of the ceNtral sleeve 26, or (as shown), grids 29a to support bread baking tin assemblies. When the oven doors 18 are opened, a finger 30 fixed to one of the door pivot brackets 19 is brought into position to intercept the approaching angle support 29 of the turntable (as shown in FIG. 2) which therefore is brought to rest in a 4

I

0 00 00 0 PP a 0*'4 0 0040 0 00 00 0 O0 0 00 0 ono 0 o0 0 0 0Oi6 0 0 00a 00 0o 4 0 00o position for the easy loading or unloading of baking trays or bread baking tins at one side of the central sleeve 26. If the doors are briefly closed and thon reopened, the turntable will turn through 180 before being brought to rest again for the loading or unloading of trays or tins at the opposite side of the central sleeve. The oven controls indicated at 31 are located at one side of the doorway 17 and electrical connections of the heating elements 22 are outside the oven chamber and the insulation 16, and are all accessible by way of an inspection door 32 at one side of the oven.

A feature of the invention resides in the steaming devices indicated generally at 33. Two such devices, oppositely arranged but otherwise similar are 15 located in the inside corners of the oven. Each consists of a series of heating plates 34 welded to and extending perpendicularly from a back plate 35, which is provided at one side with hinge lugs 36 whereby it is hinged to the back of the oven so that each assembly can be swung through an opening in the wall of the inner chamber to become located in a back corner of the oven chamber 10, and clear of the turntable The heating plates 34 are triangular, and in a vertically spaced and staggered arrangement. The top plate 34a slopes at a small angle from one side to the other, which is inset from the corresponding side of the second plate 34b, which in turn is sloped in opposite uj.ection, its lower edge being inset from the corresponding side of the third plate 34c, and so on.

Each of the plates has raised edges 37 along its free sides and, near to the lower of these edges the raised edge has a cut-away overflow opening 38. The top plate 34a is partly covered, from its apex, by a triangular top plate 39. Water can be fed onto the top plate 34a through a water inlet pipe 40 which may be connected by a flexible hose 41 to any suitable source of supply and, j after spreading across most if not ai.l of the plate, will flow through the cut-away opening 38 to fall onto the second plate 34b and from this second plate it will flow through the overflow opening not shown in the drawing of this second plate onto the third plate 34c, and so on.

To prevent escape of water flowing from the top plate 34a, the second plate 34b has a splash plate 42, and a similar splash plate 42 is provided on the third plate 34c to ensure there is no loss of water flowing from the second plate 34b. Similar splash plates may be provided on the other plates if desired, but will not ordinarily be required. To ensure that water cascading onto each of the plates below the top °o 15 one follows a circuitous path before leaving the plate, AeOO baffles 43 are fixed on the plates.

When each steaming assembly is swung into 0ooo place in the oven, it is brought directly over part of the rearmost bottom heating element 22; and the third plate 34c and fourth plate 34b are so sp~.ced that they become located over and under part of the rearmost of o the middle heating elements.

S14 o*oO 0Consequently, the steaming device are quickly heated within the oven to a high temperature and when 25 water is admitted through their inlets 38 it is rapidly converted to steam while spreading over the heating plates one after the other, so that the oven chamber 0o rapidly fills with live steam. Any deposition of 0 o o mineral from hard water will not materially affect the o operation of the steam generators, at least for a long time, after which the device may be easily removed for maintenance or replacement. Any water which flows from the lowermost heating plates 34f of the devices is received into a transverse gutter 44 from which there leads a drain pipe 6 Bakers' ovens according to the invention will be found to be very effective in achieving the objects for whi-h they have been devised. It wil" 1 of course, be understood that the particular embodiment of the invention 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 and ambit of the invention hereinafter claimed.

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Claims (7)

1. Steam generating means for a baker's oven including: an assembly of heating plates, one above the other, for location within, and heating by, the oven, and Ameans for introducing water onto a top heating plate to cascade down to the lower plate or plates in sequence and, by heat transfer from the ating plates, to be converted to steam within the oven.

2. Steam generating means according to Claim 1 wherein: the heating plates are fixed to and extend 0* from a back plate hinged to a side of an opening in a wall of the oven so that when the back plate is moved to close the opening, the heating plates are located within 0 the oven. *04,

3. Steam generating means according to either of 0 the preceding claims wherein: the heating plates incline from one side to the other, alternately in opposite directions, have side walls with outlet openings at their lower sides and are Oo:O in staggered arrangement, so that water leaving the outlet from the lower side of one will be received at 25 the higher side of the heating plate next below.

4. Steam generating means according to any one of the preceding claims wherein: S the heating plates are substantially of--ight- gle i.cclc triangular shape in plan view.

5. Sceam generating means according to any one of the preceding claims wherein: the oven is heated by electrical heating elements at the bottom, the middle and the top of the oven, two of the assemblies of heating plates are f provided at opposite sides of the rear or inner part of the oven.

6. Steam generating means according to Claim wherein: a gutter is provided within the oven with a drainage outlet leading from the oven, the gutter being arranged to receive water flowing from the lowermost of the heating plates of the two assemblies of heating plates.

7. Steam generating means substantially as herein described with reference to the accompanying drawings. DATED this twenty-fourth day of July 1989 °a APV BAKER PTY LTD 1 By their Patent Attorneys GRANT ADAMS COMPANY a- 0 o o o ra 41 0 9 a L