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Patent Searching and Data

Document Type and Number:
WIPO Patent Application WO/2014/140649
Kind Code:
A combustion mixture inlet assembly (65) for a cooking appliance (10) for barbecue grilling of food provides optimum mixing of fuel and air for maximum efficiency of the burner. The assembly (65) comprises upper and lower plates (66, 68) which are parallel and spaced from each other. A wall (72) between the plates (66, 68) defines a chamber (74). A plurality of apertures (76) in the wall (72) allow air between the upper and lower plates (66, 68) to enter the chamber (74). The chamber (74) also includes an inlet in the base for supplying fuel and an outlet in the top for delivering a fuel air mixture to the burner.

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CADBURY, George Justin Peter (Millbrook Farmhouse, BlewburyNr. Didcot, Oxfordshire OX11 9ED, GB)
Application Number:
Publication Date:
September 18, 2014
Filing Date:
March 17, 2014
Export Citation:
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ACTIVE FOOD SYSTEMS LIMITED (Millbrook Farmhouse, BlewburyNr. Didcot, Oxfordshire OX11 9ED, GB)
International Classes:
F23D14/06; A47J37/07; F23D14/62
Domestic Patent References:
Foreign References:
Attorney, Agent or Firm:
BOULT WADE TENNANT (Verulam Gardens, 70 Gray's Inn Road, London WC1X 8BT, GB)
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X, A combustion mixture inle assembly for & cooking- appliance, com ising upper and lower lates which are S parallel and spa ed from each other- by a predetermined

dis nce,, a wall secured e ween the uppe and lower plates de ining" an inner, the spaced, parallel plates extending beyond the. wall in all dir ctions to define an outer chamber surrounding the inner chamber, a plurality of apertures in.0 the wall to allow air between the upper and lower plates to enter the inner chamber, an inlet in the base of the inner chamber lor supplying fuel into the inner chamber and an outlet in the top of the inner chamber, S 2. An inlet assembly an claimed in claim 1, wherein the wall is square in order to define a square inner chamber and each of the four f ces of the square wall defines three apertures- - O 3, .an inlet assembl as claimed in claim 1 or claim 2, further comprising a burne assembly mou t d on the upper plate over the outlet, the burner defining an inner volume which communicatee with the inner chamber for receiving a combustion. mixture fro the inne chamber, ana at least one1 bar spanning the outlet ho ass s with mixing of the air and fuel ..

4. .An inlet assembly as claimed in claim 3, wherein, the burner compxaces two annular outlets tor the combustion.

0 ixpure , thereby to create dual laye flame when she

mixture is igni ed.

5. An inlet assembly as claimed in claim t further comprising a rest iction in the burner between the interior volume and the annular outle a ,

S 6. A cooking appliance comprising a base assembly of heat resistant material defining at least one aperture and at. least one inlet assembly as claimed in any of claims 1 ·· 5 , wherein an inlet assembly is located beneath the base assembly with a*, burner assembly extendin upwardly through a0 respective aperture,

?\ A cooking appliance as claimed in claim 6, wherein the base assembly defines two apertures and further comprising two inlet assemblies and two burners ,

8. A cooking appliance as claimed in claim, 6 or claim, if wherein the base assembly comprises four interlocking segtsents,. G 9. A seeking appliance as claimed in claim 8 , wherein toe base assembly comprises a first pai of segments defining male interlock ng structures and a second pair or segments defining iemaie inner locking streeturns, shore in the

segments are arranged alternately with the male interlockingi stru u es engaging the female interlocking structures .

10. A combustion mixture inlet assembly substant ally as here!abetere described and with: reference to One

accompanying drawings ..

11. a, cooking appliance substantially as hereinbefore described oith reference to the accompanying drawings.

The present inyentrlon relates to apparatus for cootang food by a barbecue grilling metbod .

OB 5 f 76 f G describee a barbsque cooking appliance: which provides first rid second sources of preoaurieed ai to improve oo¾bust on effioienoYt In practise, thia

appliance has been found liable to produce an uneven flame . , intolerant of alight changes in gas pressure. This can result in an uneven heat spread, across the grill which, is undesirable for efficient cooking of food. The present invention provides a combustion mixture inlet assembly for cooking appliance : comprising upper and. lower plates which are parallel and spaced from each other hy- a predetermined distance ; a. wall secured between the uppe and lower plates defining an inner, the spaced , parallel plates extending beyond the Wall in all directions to define an outer chamber surrounding the inner cham er, a pluralit of apertures in the wall to allow air between the upper and lower plates to enter the inner chamber, an inlet i the base of the inner chamber for supplying fuel into the inner chamber, and an outle in the top of the inner

chamber .

This arrangement provides for e fective mirung of air and fuel in order to ensure the most e ficient combustion mixture is supplied to a burner, to produce an even,

consistent and very hot flame. P ef a ly, he wall is square in order to do lee a square inner chamber and each of the tour faoee of the ocpare wall defines three apertures.

Preferably, the inlet ssembly further com rises*; a burner assembly eoxsrted on the upper plate over the outle s the burner defining an interio volume which eoqMunioatee with the inner chanter fo receiving the fuel/air mixture from the inner chamber .. and at I each one ba spanning the outlet to assist with mixing of the fuel and air.

Pr ferably, the burner assembly pro ideo two annular outlets for the fuel/air mi ture.,- thereby to create a dual layer flaoe whan the mimture is ignited, referabl i the burner includes a restriction between the interior volume and the annular ou lets . he present ineention also provides tooting applianoe comptdsing a baas assembly formed of heat resistant material defining at leaet one aperture., and at least one combust;.-.on misoinre inlet assembly as described above, wherei the inlet ssembly is located beneath the base assembly, such that a burner mounted on the inlet assembly extends upwardly through a respective aperture .

In a preferred em odiment, the base assembly dofines two apertures., a d two inlet assemblies and two bu ners are provided .

Preferably ί the base assembly of the cooking appliance comprises four interlocking segments. ;?r¾rerabXy , e se assembly comprises a first p i oi segments de ining mala interlockin atruct\rres and a saoond. pair of segments def ni g female interlocking str ctures : and the segm n s are arranged alternately i the male interlocking stru ures engaging the femal inte locking structures ,. fhe invention will now he described in detail , by way of example only, with reference to the accompanying drawings in whien;

Figure 1 is a perspective view of a base assembl ormi : part of the ap atus of the present invention;

Figure 2 c ows a male block need to create the base assembly o Figure ;

Figure 2a shows how two male blocks fit together;

Figure 3 shows a femal block need to create the bane assembly of Figure X;

Figure 3a shows ho two female blocks fit together;

Figure 3b shows a detail of Figure 3 to illustrate the undercut portio t

Figure shows a partly cue -away view: of a borne for the apparatus ; Figure 4a shows an exploded vie of the burner of Figure 4 ;

Figure 5 shows a perspective view: of the burner x.a conjunction with an inle aaaetfihly for the apparatus o the present invention;

Fieores Sa and Sb enow side a d. end views of the aeseobly of Figure ¾ ; and

Figure So shows a perspective cut-away view: of the inlet assembly of Figure 5 without the burner..

The cooking aoparatoa ID of the present invention com rises a base aeaembXy 12 formed of beat resistant ceramic tcuterial .. The base assembly IS: is a tray - like a ruecure with a base 12a and side wail 12b. The base 12a def nes apertures 14 for receiving burners 16. In this xa le the base assembly 12 receives 2 burners although an apparatus with a single burner or oore than two is a so possible.

For ease of manufacture and transport, the base

assembly 12 is preferably formed of four blocks which fit together to forts the ray- like structure. In this example, the base assetsbXy 12 comprises ¥?o male blocks IF and tero female blocks 20 arranged alternately.

Been code block: 18 ban wo outside edges 22 farming the out aide walls 12a of the base assembly 12 and two ineide walls 24 which mate with adjacent .female, biocbs . One inside edge 24 defines a semi circular opening 2-¾ . Both inside edges? 24 are stepped to form a proa acting ledge 28.. Where the two inside edges 24 meet, the ledge 28 is forced with further cat oat to provide a two-step profile 30 as heat seen in Figure 2, In use, two mala block's 18 ar : positioned diagonally opposed to one another such that tbe two-step profile 30 of one block IS ma es with the two step profile 30 of the other block IS to locate the two blocks togethe as shown in Figure 2a ,

Bach female block 20 also comprises two outaIda edges 32 forming parts of the oirtside wall 12a of the base

assembly 12, and two inside edges 34 which m e with

ad acent inside edges 24 Of the male locks 18, One inside edge M de ines a semi-circular opening 30. Both the inside edges 34 are formed with an undercut portion 30 as shown in the detail view of Figure 3b. Therefore, when assembled, the undercut portion 38 of each female block 20 receives the projecting ledges 28 of the two adjacent male blocks IS in order to locate all four blocks together to create the base assembly 12,

The semi-- circular openings 26 and 30 in the male and female blocks 18 f 20 respectively face: one another in order to define a circular aperture 14 for receiving a gas burner la. The male and feoale blocks lit 20 may further define a shallow sersi ·· circular recess around the openings- 26., 3¾ so that when assembled they for an annular recess 40 around each aperture 14. A ceramic collar 42 (seen in Figure 1) may be received in the annular recess 40 to form, a heat

resistant protec ion around th base of the burner 10, The ~ is - collar 42 and recess 40 are fofiftd wit corresponding notches 1 for receiving an ignite In use .

The perimeter wail 12b of the ceramic base 12 defines a plurality pf apertures- 44 for supplying air as described further below.

Bach teener 1.6 ce ppiees a base 44 with a cylindrical wall ail, a lower snirula flange 48 for mounting the burner 16 to another s ructure and an reaper circular wall SO defining a central opening 52 , his provides a restriction between the volume within the base 44 and the burner outle o4 which is soanted on the ba.se.44. The burner outlet 6 is made up of a eartea of washers 56... S , There are two crimped or jagged washers 56 which have a eoigaag profile, sandwiched between three flat washers SS. A circular plate 60 covers the outle 54 to provide the to o the burner if . in use, a heat reeistanf ceramic di c 62 (seen in Figure i } cay be located on the circular pla e 60 to or the top of the bnrues ,

A bar 64 extendc diametrically across the open, lower end of the burne base 44. Each bu ner 16 is mounted on a comoustioo ahotiose inlet assembly at formed of upper and lower metal plates 6 .. 6 . The burner If is secured to the upper et l plate 66 , ¾aen the cooking apparatus 10 is assembled, the upper metal plate 66 is located beneath the ceramic base assembly 12 with the burner 16 protruding up through an aperture 1 . he lower me al plate €8 lies below ana parallel to the first metal plate 66. Spacers 76 secured to the upper na lower metal elates 661 68 hold the plates at a predetermined spacleg to create a sand ich"lite stractor's .

Between the upper s.uh lower metal plates 66 , 6¾ and directly beneath the. burner 16 { a miring- chamber is created by a wall 72 which extends bes orn the plates 661 68 to enclose a chamber 74 < Preferably,, the wall 72 is square and therefore encloses a square shasurer 7 , Each of the four faces of she wall 72 defines a plurality , and preferably three, small apertures 76 f mahirp 12 apert res in total. The apertures 76 a e evenly spaced: around the wall 72. in use the lower end of she chamber 74 is closed by a closure plats containing a cen r l aperture (not shown) for receiving a, fuel supply, t ically a gas supply< he upper end of the chaober 7 is open sad cooounuoatea with, the volume within the base 44 of the burner 16. The chamber 74 formed by the wall 72 oceupi.es only a rela ively small , generally central area be oween the plates 6, 60. In other words, the plates 66 , 68 exten.d beyond the wall 76 . . still spaced and parallel to each other, as seen in Figures S-SCi The gap between, the plates 66, 68 outside the wail 72 thus defines an outer chamber surrounding the wall 72 on. all sides. Air flows through this outer chaober to the apertures 76 in th wall 72. This helps to control and smooth out the flo of air to the apertures 76,. in use, a fan {not shown) supplies pressurised air into the outer chamber, i.e., the gap between the upper and lower metal plates 66, 6S , Air eaters the ch m er 74 as a plurality of ess via the apertures 76 and mi es with gas within the c ambe 7 . The gas is i jec ed vertically upw rdly into the c a be 74 and therefore impinges on the bar 6 which s ans the opening at the lowe end of the

1 burner baee 44.. The bar 6 therefore aaisists with diffusion or pan injected into the chamber 74, to enable thorough mi i with air entering through the aper ur a 76. Further mining of gaa and air occurs in the volume formed within the burner ane 4 , This; arrangemen provides for optimuM miringP of air and gas at the desired ratio for moat ef icient

combus ion .

The gaa/ air mixture then passes up through the opening 52 in the burner base 44 and exits the burner 16 ' bp £lowingS through the gaps created between the sugsag and flat washera Sab SB, The ix are is ignited by an igniter (not shown) situated adjacen the excarlor of t e burner 164 .¾ dual layer flame Is thus created, a lower layer by ignitio o the gas/air mixture passing between the lower and middle0 flee washers 58 end an upper layer by ignition of the

gas/air mixture passing between the middle and upper washers 5¾ . This dual flame provides an extremely high teinperature for cooking over a large area.

Thus ; the arrangement of the mixing chamber 74, apertures 76 and the άiffuser bar 64 ensures th correct amount of air is injected and mixed thoroughly With gas for supply to the burner 16. If too little air is prov ided the mixture becomes too rich,, i<e, fuel, heavy, giving a leapd yellow lapping flame that will not fully atom se any fata from the food being cooked. If too much air is provided the combustion mixture becomes too lean so that the flame breaks away from he burner 16 , producing cool 11 nsa t at will ex inguish easily ' and ia highly susceptible to at dripping from the food. In use, a rack or a. solid conductive plate in planed over the ceramic h an assembly 12 a d the burners IS and food placed on the rack/piate for cooling · he fan which supplies pressurised air to the combustion mixture inlet assembly β¾ als supplies pressurised air through the

a turna 44 formed i the perimeter wall lab of the ceramic base asaao ly 1.2, This econdary air suppl flattens o impinges the heat across the surface of the ceramic bane assembly 12 giving optimum radiant heat d neribaticri across the ceramic surfaces. This assists in ensuring tha

combustion occurs as efficiently as possible and provides an extremely high temperature - Cooling at the very high

temperstnre provided by the apparatus ID ensures that fate and oils ire¾ the food are completely coohusted. Therefore, no drip tray is required to collect excess fata or oils and carbon deposits on the food or the cooking rack/plate are avoided.