US3173472A

US3173472A - Pilot burner-thermocouple combination

Info

Publication number: US3173472A
Application number: US243108A
Authority: US
Inventors: Roger S Loveland
Original assignee: Honeywell Inc
Current assignee: Honeywell Inc
Priority date: 1962-12-07
Filing date: 1962-12-07
Publication date: 1965-03-16
Anticipated expiration: 1982-03-16

Description

March 16, 1965 R. s. LOVELAND 3,173,472

PILOT BURNER-THERMOCOUPLE COMBINATION Filed Dec. 7, 1962 ga 17a 11 1 16a 2 3 20 lab I I z: I i I 12 y 166 I I 2 0: J26 "I" 5 11b I 25' I' will 15 I Ii 1 INVENTOR I f 5 flmlih 22 20621 sr'zovzmp United States Patent 3,173,472 PILOT BURNER-THERMOCOUPLE COMBINATION Roger S. Loveland, Torrance, Calif., assignor to Honeywell Inc., a corporation of Delaware Filed Dec. 7, 1962, Ser. No. 243,108 3 Claims. (Cl. 158-123) This invention relates to a combination pilot burner and flame sensor and, more particularly, to the combination of a pilot burner and a thermocouple, forming a thermoelectric generator for use in conjunction with a main burner.

Thermoelectric generators, of the same general type as disclosed herein, are well known in the prior art and are used in conjunction with electromagnetically operated safety valves to provide for the flow of gas to an associated main burner only when a pilot flame is in existence for igniting the gas issuing from the main burner.

It is one of the objects of this invention to provide a less expensive, yet strong and reliable combination of a flame sensing unit and a pilot burner, for heating the unit and for igniting a main burner, and supported by a very simple bracket construction.

Another object of the invention is to provide a mounting bracket for a pilot burner and an associated flame sensor, which is made of a single piece of sheet metal.

Another object of the invention is to provide a sheet metal supporting bracket for a pilot burner and an associated flame sensor which is inexpensive yet, due to the shape thereof, provides a very rigid and strong construction that is easily formed and assembled with its associated parts.

Other objects of the invention will become apparent upon reading the following detailed description of the invention in conjunction with the accompanying drawing wherein:

FIGURE 1 is a perspective view of the invention;

FIGURE 2 is a plan view of the invention; and

FIGURE 3 is a side elevational view of the invention, with portions of the supporting means for the flame sensing unit broken away.

The thermoelectric generator comprises a generally T-shaped bracket member 11 made of heavy gauge sheet metal and having two

apertures

12 and 13 in the head portion thereof for the reception of bolts (not shown) to mount the bracket on a main burner (not shown). The bracket member has an arcuate bend 14 intermediate its length and a similar but reverse arcuate bend 15 near its outer end or the end away from the head thereof. The arcs of the bends are of substantially the same radius and length so that the arm or portion 11a of the bracket member adjacent the head is substantially parallel to the arm or portion 11b of the bracket member at its outer end, with the portion 11c extending diagonally therebetween.

A tubular support 16 for a flame sensing unit, which, in the preferred embodiment, is a thermocouple 17, has an inwardly extending annular flange 160 which provides an abutment shoulder 16b around an opening 160 in its upper end.

To aid in securing the tubular member 16 to the bracket 11 in the arcuate portion 14, two dimples 18 and 19 were made in the opposite side of the bracket member to form slight protrusions from the arcuate surface 14 so that when the tubular portion was clamped to the bracket member by welding electrodes and current passed through the bracket and the tubular member, the protrusions were melted to form spot welds 18a and 19a to snugly hold the tubular member in the arcuate portion 14 of the bracket.

Extending through the opening 160 is a conventional split sleeve 20 made of resilient material, such as steel, which has a notch 20a therein opposite a longitudinally extending slot 20c and inwardly struck portions 20b forming two inwardly extending arcuate portions adapted to register with an annular groove 17a formed in the thermocouple 17. The lower end of the split sleeve 20 has an outwardly extending flange portion 200 that bears against the shoulder 16b of the holder 16. Outwardly struck arms 20d bear against the upper surface of the flange 16a and cooperate with the flange 200 to hold the resilient member 20 in assembled position. The member 20 is placed in the illustrated assembled position by inserting it into the bottom of the tubular member 16 and forcing it through the member by springing the arms 20:! inwardly as it slides through the interior of the sleeve and through the opening 160, whereupon the arms 20d can spring outwardly into position over the flange 16a.

The flame sensing unit or thermocouple 17 is positioned in the holder 16 and the split sleeve 20 by also being inserted through the bottom of the sleeve 16 and the member 20, by resiliently biasing the inwardly extending portions 20b outwardly by a camming action of the thermocouple, so that the enlarged diameter portion 17b adjacent the groove 17a may pass therethrough, permitting the inwardly extending portion 20b to resiliently snap into the groove 17a and retain the thermocouple 17 in its assembled position. The thermocouple has two enlarged diameter portions 17c, which is only slightly less than the inside diameter of the

sleeve

16, and 17d, which is somewhat larger than the inside diameter of the sleeve 16, to serve as means to abut against the lower end of the sleeve 16 and limit the inward movement of the thermocouple with respect to the sleeve.

A pilot burner comprising a cylindrical body portion 21, having a reduced diameter portion 21a, is internally threaded at its lower end to receive a pipe coupling 22 for connecting a supplied pipe 23 to the burner body. A target type of burner head 24 has a cylindrical portion 24a that fits into the upper end of the reduced diameter portion 21a and a flame directing portion 24b for directing the flame over the flame sensing unit and to the side of the flame sensing unit for igniting the main burner. An outwardly struck tab 24c of the member 24 serves to anchor the head 24 non-rotatably in one of a pair of notches 211) formed in the upper edge of the burner body.

The forming of

dimples

25 and 26 in the opposite side of the bracket and at the ends of the arcuate bend 15, provided protrusions against which the burner body was forced at the time of holding it on the bracket for the welding operation. Spot welds 25a and 26a resulted when current was passed through the burner body and the bracket, as in the welding of the sleeve 16 to the bracket.

It is thus seen that, due to the bends in the sheet metal forming the bracket, the bracket member provides a very rigid mounting and, due to the positioning of the flame sensing holder and the burner body in the bends of the bracket, these members are properly spaced and aligned with each other by a very simple and inexpensive assembling technique.

The invention is illustrated as having an arrangement whereby if the bracket 11 were bolted to a main burner by having bolts pass through the

openings

12 and 13 therein and into the main burner, with the conduit 23 connected to a source of fuel, a flame from the burner head 24b would impinge on the upper end of the thermocouple 17, with portions of the flame passing by the thermocouple, with at least one portion thereof flowing in a direction toward the main burner. The head is so designed that should the flame portion for igniting the main burner become sufficiently small so as to be incapable of lighting the main burner, the portion of the flame playing on the thermocouple will cease to heat the thermocouple sufiiciently to cause it to energize a conventional safety valve to which it is connected, causing the gas to the main burner to be cut off.

Should it be necessary to replace the thermocouple, it may be removed from its holder 16 by merely pulling downwardly on the concentric lead 17e connected thereto. The enlarged diameter portion or rib 17b will cam the detents or inwardly extending portions 20b outwardly to permit the rib 17b to move downwardly and thus free the thermocouple for outward movement from the holder 16. A new thermocouple may be installed by merely forcing it through the holder 16 and through the spring clip 20, as in the initial assembly thereof.

As modifications may be made in the invention without departing from the spirit thereof, the scope of the invention should be determined from the appended claims.

I claim:

1. A safety pilot comprising a bracket having a pair of spaced arcuate bends therein to provide a pair of longitudinally offset and generally parallel arms joined by an intermediate portion; a tubular support for holding a temperature sensing unit and having a radius substantially the same as the radius of said arcuate bends mounted in one of said bends; a tubular pilot burner body having a radius substantially the same as the radius of said arcuate bends and mounted in the other of said bends, said tubular support and tubular pilot burner body being secured to said bracket in said bends by means located at said bends; 30

and means for securing said temperature sensing unit in said support.

2. In a safety pilot the combination comprising a metal bracket having a pair of bends therein to provide a pair of longitudinally offset and generally parallel arms joined by an intermediate portion; a tubular support, for holding a temperature sensing unit, mounted in one of said bends; a tubular pilot burner body mounted in the other of said bends, with said intermediate portion lying therebetween; and means for detachably securing said temperature sensing unit in said support.

3. A safety pilot comprising a sheet metal bracket having a pair of bends therein to provide a pair of generally parallel arms joined by an intermediate diagonally extending portion; a tubular support, for hoding a temperature sensing unit, mounted in' one of said bends, said support an internal annular flange at one end thereof and a spring clip member extending through and mounted on said flange for resiliently engaging the temperature sensing unit; and a tubular pilot burner body mounted in the other of said bends, with said intermediate diagonally extending portion lying therebetween.

References Cited by the Examiner UNITED STATES PATENTS 888,791 5/08 Drake 248-68 2,236,882 4/41 Vorkauf 248 68 2,299,001 10/42 Anderson 2l993 X 2,688,064 8/54 Traver 158135 X 2,799,331 7/57 Hagny 158-123 2,817,696 12/57 Beck l364.13

FOREIGN PATENTS 214,112 3/61 Austria.

JAMES W. WESTHAVER, Primary Examiner.

FREDERICK L. MATTESON, JR., Examiner.

Claims

1. A SAFETY PILOT COMPRISING A BRACKET HAVING A PAIR OF SPACED ARCUATE BENDS THEREIN TO PROVIDE A PAIR OF LONGITUDINALLY OFFSET AND GENERALLY PARALLEL ARMS JOINED BY A INTERMEDIATE PORTION; A TUBULAR SUPPORT FOR HOLDING A TEMPERATURE SENSING UNIT AND HAVING A RADIUS SUBSTANTIALLY THE SAME AS THE RADIUS OF SAID ARCUATE BENDS MOUNTED IN ONE OF SAID BENDS; A TUBULAR PILOT BURNER BODY HAVING A RADIUS SUBSTANTIALLY THE SAME AS THE RADIUS OF SAID ARCUATE BENDS AND MOUNTED IN THE OTHER OF SAID BENDS, SAID TUBULAR SUPPORT AND TUBULAR PILOT BURNER BODY BEING SECURED TO SAID BRACKET IN SAID BENDS BY MEANS LOCATED AT SAID BENDS; AND MEANS FOR SECURING SAID TEMPERATURE SENSING UNIT IN SAID SUPPORT.