US2834408A - Pilot burner - Google Patents

Description

H. c. REINHART ET AL 2,834,408

PILOT BURNER May 13, 1958 Filed April 12. 1954 3 Sheets-Sheet 1 May 13, 1958 H. C. REINHART ET AL PILOT BURNER 3 Sheets-Sheet 2 Filed April l2, 1954 May 13, 1958 PILOT BURNER 5 'Sheets-Sheet 3 Filed April l2, 1954 PILOT BURNER Harold C. Reinhart, Ferguson, and Eugene P. Portas,

Aton, Mo., assignors to Magic Chef-Food Giant Markets, line., a corporation of New Jersey Application April 12, 1954, Serial No. 422,412

8 Claims. (Cl. 158-115) This invention relates to pilot burners, and more particularly to gas-burning pilot burners such as are used in cooking ranges and other gas-burning appliances for main burner ignition.

The principal object of the invention is the provision of a pilot burner of the class described which may be operated with a much smaller flame than heretofore regarded as necessary for stability, thus reducing gas consumption and the amount of heat given olf by the burner, and without undue danger that the flame will be extinguished by drafts or upon main burner ignition. For example, in the case of the usual pilot burner for igniting the top burners of a cooking range via flash tubes, it has heretofore been customary to operate the pilot burner with at least a 200 B. t. u. per hour llame (approximately) in order to insure stability of the llame. In the case of the present invention, the pilot burner may be operated with as low as a 50 B. t. u. per hour iiame (approximately) without undue danger of extinguishment. Heretofore, it has not been believed possible to use such a small flame because of its instability as compared to the larger ame. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated, Y

Fig. 1 is a plan View illustrating a pilot burner of this invention as used in a so-called divided top cooking range, partly in section on line 1-1 of Fig. 2;

Fig. 2 is a vertical cross section taken on line 2-2 of Fig. l;

Fig. 3 is a vertical cross section taken on line 3--3 of Fig. 2;

Fig. 4 is a plan view illustrating a modied type of pilot burner of this invention as used in a so-called cluster top cooking range, partly in section on line 4 -4 of Fig. 5;

Fig. 5 is a Vertical section taken on line 5--5 of Fig. 4;

Fig. 6 is a plan view of a pilot burner of this invention as used in conjunction with a griddle burner in a cooking range;

Fig. 7 is a side elevation of Fig. 6, in vertical cross section on line 7 7 of Fig. 6; and,

Fig. 8 is a vertical cross section taken on line 8 8 of Fig. 7.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, Figs. 1-3 show a pilot burner 1 of this invention as it is used in a burner assembly for a divided top cooking range of the type shown in Figs. lS-ZO of the coassigned copending application of Almer H. Brodbeck and Harold C. Reinhart entitled Burner Assembly for Cooking Ranges, SerialNo. 394,921,

l assises Patented May 13, 195s iiled November 30, 1953. This type of burner assembly includes two main burners, with the pilot burner located generally centrally between the main burners and adapted to ignite the main burners via straight dash tubes T extending in opposite directions to the main burners from opposite sides of the pilot burner. Only a fragment of the burner assembly is shown in Figs. l and 2. Reference may be made to the stated copending application for full details. At 3 is shown the sheet metal tray of the assembly, and at 5 one of two integral circular burner-supporting cuis of the tray. The burner which is carried by the cuff 5 is not shown. At I is indicated a bottom plate, and at 9 is shown an opening in plate 7 with an upstanding flange 11 around the opening. The cuit 5 has a nozzle 13 for directing gas into the respective flash tube. A support for the ash tubes is indicated at 15. A portion of the top tray of the range over the pilot burner is indicated at 17 in Fig. 2. A fragment of a grate is indicated at G in Fig. 2.

The pilot burner 1 comprises a sheet metal cup 19 having a central bottom opening 21. The cup 19 is mounted above the bottom of the tray 3 on a thimble or hat-shaped support 23. At 25 is shown a pipe for supplying gas to the pilot burner. This pipe extends up through the support 23 to the crown of the support, and

a pilot burner spud 27 is threaded into the upper end of the pipe through the opening 21 in the bottom of the cup and through a correponding opening in the crown of the support 23. This holds the cup on the support. The cup 19 has two diametrically opposite side openings 29 for entry of gas from the two iiash tubes T. These openings are formed by striking in portions 31 of the cylindrical wall of the cup. Portions 31 are angled to act as baffles for gas entering the cup through the openings 29.

The cup also has two diametrically opposite inwardly extending horizontal ears 33. These are struck in from the top of the cylindrical Wall of the cup on a line at to the line of openings 29. The cup is also formed with slots 35 toward its bottom for entry of secondary air. A iilament 37 has its ends secured to the ears 33 and extends across the cup above the top of the spud. Filament 37 preferably consists of a length of tine nichrome Wire (0.15 inch in diameter, for example). It is shown as being formed with a central downward loop 39 located to be positioned in a small pilot flame. As illustrated, the ears 33 have holes 41 receiving bent end portions 43 of the tilament. The top of the spud 27 is located above the bottoms of the inner ends of the flash tubes. This s required due to the tact that the pilot llame is so small that all the flame should be above the bottoms of the tubesto eiect ignition. The cup 19 is mounted on the support 23 with openings 29 in line with the Hash tubes. A top shield for the pilot burner is indicated at 45. This is provided to reduce the temperature of portion 17 of the top tray.

The pilot burner is supplied with gas to operate with a very small flame (approximately 5() B. t. u. per hour, for example). The flame hugs the loop 39 of filament 37 and heats it to incandescence. The filament acts to sta-` bilize the flame against being extinguished by being blown out or by being pulled oit the Spud by drafts. When a main burner is turned 0n, gas tlows through the respective ash tube T and enters the pilot cup 19 through the respective opening 29. The baffle 31 for this opening diverts the surge of gas flowing through the opening to one side of the small pilot flame to protect the ame from being blown out by the surge. The gas is ignited by the pilot ame, and the main burner is ignited by ash back through the flash tube. The baffle 31 then acts as a restricter for the opening 29 to aid the filament in preventing the pilot iiame from being extinguished by being pulled off the spud. The cup 19 at all times `acts as a shield to aid the filament in protecting the fiame from being blown out by drafts.

Figs. 4 and 5 show a modification of the pilot burner such as is used in a cluster top cooking range of the type shown in Fig. l of the above-mentioned copending application. The pilot burner is here designated 51 in its entirety. The cluster top range includes a cluster of four main burners, with the pilot burner located at the center of the cluster, and adapted to ignite the main burners via curved flash tubes such as indicated at T radiating from the pilot burner to the main burners. The range in cludes two identical burner assemblies, each including two burners. A fragment of one such assembly is shown in Figs. 4 and 5. Reference may be made to the stated copending application for full details. At 53 is shown the sheet metal tray of the two-burner assembly, and at 55 one of two integral circular burner-supporting cus of the tray. The burner which is carried by the cuff is not shown. At 57 is indicated a bottom plate, and at 59 is shown an opening in plate 57 with an upstanding flange 61 around the opening. The cuff 55 has a nozzle 63 for directing gas into the respective flash tube. A portion of the top tray of the range Over the pilot burner is indicated at 64 in Fig. 5.

The tray 53 has a side recess 65 accommodating the pilot burner 51. The latter comprises .a base 67vwhich is xed on the upper end of the pilot burner gas supply pipe 69 by the spud 71 of the pilot burner. The base 67 consists of a dished sheet metal member having a raised central portion 73. This has a central opening 75 receiving the spud. It also has openings 77 for admitting secondary air from below. At diametrically opposite sides of the base are upward projections 79. The recesses between the projections are designated 81. The inner ends of the two flash tubes T shown in Fig. 4 bear on the rim of the base in one of these recesses 81. It will be understood that in the cluster top range there will also be two more ash tubes having their inner ends bearing on the rim of the base in the other recess.

At 83 is shown a pilot burner cup member surrounding the Spud 71. This consists of a frusto-conical sheet metal member having an outwardly extending flange 85fat its bottom welded to the bottom of the base 67 outward-of the secondary air openings 77. The upper end of the cup member 83 is formed with upward projections 87 at ,opposite sides, the ends of the projections being bent inward to provide horizontal ears 89 located above the rim of the cup member. The top of the spud 71 is located somewhat below the rim of the cup member, and above the bottoms of the inner ends ofthe ash tubes. Thus, the pilot fiame extends above the rim of the cup member and is located entirely above the bottoms of the inner ends of the fiash tubes. A filament 91 corresponding to the filament 37 has bent end portions 93 received in holes 95 in the ears and extends across the top of the cup member above the top of the spud. The central downward loop of the filament is designated-97 and is located to be positioned in a small pilot flame. The loop` is located above the rim of the cup member. A top shield 99 is provided to reduce the temperature of portion 64 of the top tray.

The pilot burner 51 is operated with a very small flame like the burner 1, and the filament 91 acts to stabilize the ame like the filament 37. The surge of gas through a flash tube T upon turning on a main burner is diverted from the base of the fiame by the cup member 83 to prevent the fiame from being blown out by the surge. The cup member also aids to prevent outage upon flash back, and also acts as a shield to protect the flame from being blown out by drafts.

Figs. 6-8 show a pilot burner of this invention as it is used in conjunction with a griddle burner. In this case there is no liash tube. The pilot burner is the same as that shown in Figs. l-3 and is again designated 1. The

' charge port 109.

griddle burner is designated 101. It has an integral bracket 103 formed with a slot 105 receiving the upper end of the pilot burner supply pipe 107. The bottom of the pilot burner cup 19 bears on the top of the bracket, and the spud 27 is threaded into the upper end of the pipe. The griddle burner has a charge port 109 in its end toward the pilot burner for delivery of gas from the griddle burner to the pilot burner, and a slot 111 intersecting the charge port for spreading the flame to the main griddle burner ports. The pilot burner cup 19 is mounted with one of the openings 29 in line with the Ignition occurs upon turning on the griddle burner by ow of gas from the griddle burner into the pilot burner cup via the baffled opening 29 and by flash back through port 109 and slot 111.

ln view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

l. A pilot burner comprising a sheet metal cup, said cup having a bottom and a side wall, portions of the side wall being struck in to provide side openings for entry of gas, .said struck-in portions being angled to act as baffles for the openings, a spud at the bottom of the cup, and a filament extending across the cup above the top of the spud in position to be located in the pilot flame for stabilizing the fiame.

2. A pilot burner comprising a sheet metal cup, said cup having a bottom and side wall, portions of the side wall being struck in to provide side openings for entry of gas, said struck-in portions being angled to act as bafes for the openings, said cup also having openings for entry of secondary air, a spud at the bottom of the cup, and a wire extending across the cup having a downward loop above the top of the spud in position to be located in the pilot flame for stabilizingthe flame.

3. A pilot burner comprising a sheet metal cup having struck-in portions at opposite sides providing side openings for entry of gas, said struck-in portions being angled to act as bafiies for the side openings, said cup also having at least one opening for entry of secondary air, a spud at the bottom of the cup, struck-in ears at opposite sides of the cup toward its top, and a filament having its ends ksecured to the ears extending across the cup above the top of the spud in position to be located in the pilot fiame for stabilizing the flame.

4. A pilot burner as set forth in claim 3 wherein said ears are formed with holes and wherein the filament has bent end portions received in said holes in the ears.

5. A pilot burner as set forth in claim 3 wherein the filament has a downward loop above the top of the spud.

6. A pilot burner comprising a base, a spud fixed on the base, a cup member on the base surrounding the spud, said base having openings for admitting secondary air to the cup member, said cup member having upward projections at opposite sides at its upper end, the ends of said projections being bent in to provide inwardly extending ears above the rim of the cup member, the top of the spud being located below the rim of the cup member, and a filament having its ends secured to the ears and extending across the cup member above the top of the Spud in position to be located in the pilot ame for stabilizing the llame.

7. A pilot burner as set forth in claim 6 wherein said ears are formed with holes and wherein the filament has bent end portions received in said holes in the ears.

8. A pilot burner as set forth in claim 6 wherein the filament has a downward loop above the top of the spud.

A (References on following page) 5 References Cited in the file of this patent 2,112,000

UNITED STATES PATENTS v 613,990 Guyenot Nov. 8, 1898 1,688,487 Dester Oct. 23, 1928 5 2,015,405 Leins Sept. 24, 1935 14,410

Stuckenholt et al Mar. 22, 1938 Marvin Apr. 26, 1938 Barna Feb. 28, 1939 FOREIGN PATENTS Great Britain of 1887

Images