AU667488B2

AU667488B2 - Gas burner

Info

Publication number: AU667488B2
Application number: AU28326/92A
Authority: AU
Inventors: Andrew Sidney Crook; Graeme Ross Morton
Original assignee: Wundowie Foundry Pty Ltd
Current assignee: Wundowie Foundry Pty Ltd
Priority date: 1991-11-12
Filing date: 1992-11-12
Publication date: 1996-03-28
Anticipated expiration: 2012-11-12
Also published as: AU2832692A

Description

667488

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION For a Standard Patent

ORIGINAL

TO BE COMPLETED BY APPLICANT 0 01 o e o oi a o oo o v 0 Name of Applicant: Actual Inventors: Address for Service: WUNDOWIE FOUNDRY PTY LTD ANDREW SIDNEY CROOK and GRAEME

MORTON

ROSS

0 00 o 0 oa 9 1 WRAY ASSOCIATES, Primary Industry House, 239 Adelaide Terrace, Perth, Western Australia, 6000.

Attorney codei WR Invention Title: "Improved Gas Burner" Details of Associated Provisional Applications: Nos: PK9444.

The following statement invention, including the me:is a full description of this best method of performing it known to 1 -2- THIS INVENTION relates to a gas burner.

In barbecues and other underfired cooking units which operate on gaseous fuels, it is common to use a gas burner having an inner combustion chamber and a mixing tube at one end which opens onto the combustion chamber.

Typically, the burner is formed with a multitude of holes arranged in a line at spaced intervals along each longitudinal side of the combustion chamber. The holes open onto the inner combustion chamber and define burner ports.

Use of holes as burner ports has disadvantages. One such disadvantage is that the gas burners are made of cast material and it is necessary to form the holes by a machining process after the casting operation. This adds significantly to the cost of production of the gas burners. A further disadvantage of holes as burner ports is that there is a tendency for the holes to become blocked by foreign matter.

One object of the present invention is to provide a gas burner that overcomes "the above-mentioned disadvantages.

The present invention provides a gas burner comprising an elongated body having two longitudinal sides one or both of which may be provided with a slot to form a burner port, the body comprising first and second parts formed by casting S° oand joined together at a mating plane, the or each slot being defined between two spaced apart surfaces one on the first part of the body and the other on the second part of the body, the surface on the second part being at the mating plane, an underside of the first part comprising a planar face defining one surface of said burner ports, the second part having a recessed portion which cooperates with the first part to define a combustion chamber within the body, the second part having a mating face at the mating plane for mating engagement with the planar face of the first part and wherein the other surface of the or each burner port is spaced from the mating face, whereby a parting line T -3formed in the second part during its casting is spaced apart from the mating face thereof.

Preferably, the first and second parts of the body are releasably joined together.

This allows the two parts to be separated for cleaning and maintenance, if necessary.

The mating face may comprise surfaces defined by a plurality of spacer portions formed on the second part of the body. Preferably, there are spacer portions at the ends of the slots. There may also be spacer portions at intervals along the length of the slots.

0o The first and second parts of the body are preferably formed of cast material, typically cast iron.

0000 0 0 Preferably, the body has a central combustion chamber onto which the burner ports open, the combustion chamber extends longitudinally along the body and is defined between the planar face of the first part and a recessed portion within o 0 the second part.

The first part is preferably an upper part and the second part is preferably a 000lower part of the burner.

The planar surface of the first part preferably extends outwardly beyond the slots in the body to define a ledge above the burner ports. With this arrangement, the ledge is immediately above the burner port and so has the effect of holding the flame onto the port during use; that is, the ledge deters flame lift.

The lower part of the body is preferably formed with a mixing tube, the outlet end of which opens onto the combustion chamber, the other end of the mixing tube T* l~-t~EL;r*;~rr~;ar~ -Isr -r~ 4 having an opening to receive a gas injector, and an air port formed in the mixing tube adjacent the opening, the air port opening in a downward direction.

The body may be provided with a cross-over line extending between the burner ports to facilitate ignition at both ports.

Preferably, the or each slot opens onto and extends substantially the full length of the combustion chamber.

Preferably, there is provided a further slot defining a burner port on each longitudinal side of the body.

i 4 4 !i ooi a o 0 1r .004 L The invention will be better understood by reference to the following description of one specific embodiment thereof as shown in the accompanying drawings in which:- Fig. 1 is a perspective view from above of a gas burner according to the embodiment; Fig. 2 is a perspective view from below of the gas burner according to the embodiment; Fig. 3 is an exploded view showing the upper and lower parts of the gas burner; Fig. 4 is a side elevational view of the gas burner; and Fig. 5 is a cross-sectional view on the line 5-5 of Fig. 1.

4 4 The embodiment shown in the drawings is directed to a gas burner for a barbecue.

The gas burner comprises a body 10 of two parts, being an "upper part 11 and a lower part 12. The upper and lower parts are made of cast iron and are releasably joined together at a mating plane 13 by machine screws 14. The machine screws 14 extend through screw holes 15 in the upper part and engage internal thread formations 16 in the lower part.

oo The upper part 11 has a planar underside 17 and an upper side 19 which incorporates reinforcing ribs 21.

The lower part 12 includes a recessed portion 23 which is closed by the upper part 11 when the two parts are joined together. The recess portion 23 co-operates with the underside 17 of the upper part 11 to define a combustion chamber 25 within the body. The combustion chamber 25 is elongated and extends along the length of the body.

ML -6 The gas burner has two burner ports 31 which open onto the combustion chamber 25. Each burner port 31 is in the form of a slot 33 which extends along one longitudinal side of the combustion chamber. Each slot 33 is defined between two spaced apart surfaces, one being an upper surface 35 on the upper part 11 of the body and the other being a lower surface 37 on the lower part 12 of the body. The planar underside 17 of the upper part 11 of the body defines the upper surface 35 of each slot. The lower surface 37 of each slot is defined by a recessed section 39 on the lower part of the body, the recessed section being located below the mating plane 13 between the upper and lower parts of •o othe body.

0! The second part 12 has a mating face 40 for mating engagement with the planar underside 17 of the upper part 0 11 of the body when the two parts are joined together. The mating face 40 comprises surfaces 41 defined by a plurality of spacer portions 43 formed on the lower part of the body.

0o °The spacer portions 43 include end spacer portions 0 20 located at the ends of the combustion chamber and intermediate spacer portions 47 located at intervals along 0 0 the length of the combustion chamber.

000o00 When the upper and lower parts of the body are joined 0 o together, the spacer portions maintain the upper surface S 25 and lower surface 37 of each slot in spaced apart relationship so as to define the burner port.

The casting procedure for casting of the lower part 12 of the body is such that the parting line for the mould employed in the procedure is spaced inwardly from the mating face 40 and the two lower surfaces 37 of the slots.

This arrangement provides good edge accuracy at the mating face and at the two lower surfaces 37, with the result that the need for foundry fettling is avoided.

i i; r 7 The lower part 12 of the body is provided with a transverse slot 49 which extends between the two lower surfaces. The transverse slot provides a cross-over line which extends between the two burner ports and so facilitates ignition at both ports. The slot 49 is formed by a saw-cutting process. The two sections of the lower part on opposed sides of the slot 49 are retained together by bridging sections The width of the upper part 11 of the body is greater than the width of the lower part 12, with the result that the planar underside 11 of the first part extends outwardly 0ooo beyond the slots 33 to define a ledge 51 above each of the 0 burner ports 31. With this arrangement, the ledge 51 is S0 0 disposed immediately above the burner port 31 and so has °000 15 the effect of holding the flame onto the port during use.

00 0 This deters flame lift-off which can be a problem with conventional gas burners which typically have such a ledge but it is somewhat ineffective because of a spacing between a..

0 0 0the ledge and the line of spaced holes which define the ooo o 00Q 00" 20 burner ports.

0000 The lower part 12 of the body is formed with a mixing tube 0000 52 having an outlet end 53 which opens onto the combustion chamber. The mixing tube has an inlet end 55 provided with *4 0 an opening 57 for receiving a gas injector of known type.

S 25 A port 59 for intaking primary air for the combustion process is provided in the mixing tube 52 at a location adjacent the inlet end 55. The air port 59 opens in a downward direction for the purpose of avoiding contamination of the mixing tube with foreign matter which might otherwise fall into the mixing tube through the opening.

L i.

-8- The gas burner according to the embodiment is simple to manufacture in comparison to conventional gas burners. The upper and lower parts 11 and 12 respectively are produced by a casting process. After completion of the manufacturing procedures, the two parts can be assembled together. The burner ports 31 are formed when the two parts are brought together, so avoiding the need for additional machining operations which could introduce i foreign materials such as swarf.

A benefit of the two part construction of the burner is that the parts can be separated as desired to allow internal inspection during manufacture and maintenance and cleaning during use.

qm From the foregoing, it is evident that the embodiment provides a gas burner which is comparatively simple in construction and which obviates the need for a multitude of holes in the burner to provide burner ports.

o ip It should be appreciated that the scope of the invention is not lintted to the scope of the embodiment described.

i

CC

a 4 4 Cc :iia IL- I

Claims

1. A gas burner comprising an elongated body having two longitudinal sides one or both of which may be provided with a slot to form a burner port, the body comprising first and second parts formed by casting and joined together at a mating plane, the or each slot being defined between two spaced apart surfaces one on the first part of the body and the other on the second part of the body, the surface on the second part being at the mating plane, an underside of the first part comprising a planar face defining one surface of said burner ports, the second part having a recessed portion which cooperates with the first part to define a combustion chamber within the body, the second part having a mating face at the mating plane for mating engagement with the planar face of the first part and wherein the other surface of the or each burner port is spaced from the mating face, whereby a parting line formed in the second part during its casting is spaced apart from the mating face thereof.

2. A gas burner according to claim 1, wherein the first and second parts of "the body are releasably joined together. S 20

3. A gas burner aucording to claims 1 or 2, wherein the mating face comprises surfaces defined by a plurality of spacer portions formed on the second part of the body.

4. A gas burner according to claim 3, wherein the spacer portions include end spacer portions at the ends of the slots.

A gas burner according to claim 4, wherein the spacer portions include intermediate spacer portions at intervals along the length of the or each slot.

6. A gas burner according to any one of the preceding claims, wherein the or each burner port opens into the combustion chamber, the combustion chamber extending longitudinally along the body. I

7. A gas burner according to any one of the preceding claims, wherein the second part of the body is formed with a mixing tube, the outlet end of which opens onto the combustion chamber, the other end of the mixing tube having an opening to receive a gas injector, and an air port formed in the mixing tube atd'V.cent the opening, the air port opening in a downward direction.

8. A gas burner according to any one of the preceding claims, wherein the body is provided with a cross-over line extending between the burner ports to facilitate ignition at both ports.

9. A gas burner according to any one of the preceding claims, wherein the planar surface of the first part extends outwardly beyond the slots in the body to define a ledge above the burner ports. 0 0 o o

10. A gas burner according to claim 9, wherein the or each slot opens onto and extends substantially the full length of the combustion chamber.

11. A gas burner according to claim 9 or 10, wherein there is provided a slot o°i ~20 defining a burner port on each longitudinal side of the body.

12. A gas burner substantially as herein described with reference to the o o accompanying drawings. Dated this THIRTY FIRST day of JANUARY

1996. WUNDOWIE FOUNDRY PTY LTD Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant v a, 1