US2605822A - Flash tube - Google Patents

Description

Aug. 5, 1952 P. HOLLMAN 2,605,822

FLASH TUBE Original Filed Jan. 25, 1946 I 2 $HEET$SHEET 1 JNVEN TOR.

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P. I. HOLLMAN Aug. 5, 1952 FLASH TUBE 2 SHEETS-SHEET 2 Original Filed Jan. 25, 1946 INVENTOR. 73):, J W BY Arrrs.

Patented Aug. 5, 1952 FLASH TUBE Feter I. Hollman, Rockford, 111., assignor to Geo.

D. Roper Corporation, Rockford,- Ill., a corporation of Illinois Original application January 23, 1946, Serial No. 642,941. Divided and this application May 4, 1949, Serial No. 91,373

9 Claims. (Cl. 158-415} This invention relates to lighting devices and more particularly to flash tubes for flashing a flame from one pilot burner to another.

Gas range manufacturers have for some time been attempting to design a satisfactory lighting system for gas ranges and stoves wherein all the burners, that is, the oven burner and broiler burners as well as the top burners, may be lighted from a single constantly burning pilot burner. One of the difliculties encountered in attempting to design such a system has been in the construction of means'for flashing the flame from thebonstantly burning pilot burner to a pilot burner used in lighting one of the main burners. In conventional ranges the constantly burning pilot burner is mounted'at the top of the stove and the oven burner and broiler burners are generally located at a lower level in th'e'range. While very little trouble is experienced in flashing flame between laterally spaced burners, considerable' difiiculty has heretofore been'experienced in satisfactorilyfiashing' a flame in evertical direction. "The problem of constructing flash tube means which will operate satisfactorily between the difierent levels at which the burners are located is complicated by the fact that throughout the country there ar a number of different standard gaseous fuels having widely varying combustion characteristics. For example, onepart of the country uses'natural gas requiring 12 cubic feet of air per cubic foot of gas for combustion and another part of the country uses manufacturedgas which requires only 4 cubic feet of air per cubic foot of gas. Thus the air requirements for different fuels may vary as much as 306%.

time as the pressure conditions of the system or the composition of the gas changes. Because of the many variations encounteredfiash tubes have not been satisfactory for all prior types of monufactured and natural gases under all service conditions.

' An object of this invention is the provision of a flash tube which may be used with a relatively largevariety of manufactured and natural gases. -Another. object of the invention is to provide Furthermore the air requirements for any given fuel may vary from time to a 'flash tube construction that is simpleto conof aflash tube construction which not only may' befused to-fiash flame between laterally spaced burners, but which positively effects the flashing of flame in a vertical direction or component thereof between burners at difierent levels. i Other objects and advantages of the'invention will become apparent from the following detailed description taken in connection with the ac-. companying drawings, in which Figure l is a perspective view of an oven lighting system utilizing a flash tube embodying; the present invention; V Fig. 2 is an enlargedperspective view cr-the flash tube showing details ofconstruction; 1 Fig. 3 is a fragmentary elevation view of oneside of the flash tube showingthe details of cion struction; Fig. 4-is an elevationview of another side of the flash tube; Figs. 5 and 6 are sectional views taken substantially along the lines 55 and 6-6 of Fig, 3,.re-, spectively; V g

Fig. '11s a perspective view of a modification .of the flash, tube construction shown in Fig; 2;; Y ,Fig. 8 isan. elevation view ofone side of :the flash tube shown in Fig. 8, and Figs. 9jand 10 are a sectional view taken substantially along the lines 9-9 and IO-j-Iil irespectively of Fig. 8. l 1, Referring now to the drawings the invention is shown embodied in a lighting system for 'a main burner. For purposes ofjillustrating theinvention th main burner is in thevform of'an oven. burner ll located beneath a conventional oven on a range, not shown, for purposes of simplifying the drawings. The main burner l l is i001).- nected to 'a gas manifold |2.,th1011gh;3,. mixing tube [3. a conduit [4, a safety valve 16, aJcOn-J duit IT, a temperature control and shut-ofi valve" I8 mounted on. and-in communication with-the gas manifold 12. An ovenv pilot burner l9.at:one end .of a support arm BI is disposed .adjacentthe oven burner. I l for purposes of lightingthelatter- The pilot-burner I 9 is connectedto the gasmani fold 12 through av passageway 22 in thecarm 2|," a. mixing tube 20 and a conduit 23 connecte'dto. the temperature control unit I8; Flash means including-'a.,,sub.-burner 26 is disposed lbetweena constantly burning pilot burner 21,1 mounted at the top of the range, and the oven pilot burner. l9 forgigniting theoven burner I I from, the con. stan'tly burning pilot burner 21. The sub-burner 26 is connected'to .the gas manifold l21=through a flmixing; tube 25,12 conduit 28:.andran' auxiliary.

i twh n t a et ve. 6 o n' the saf t valv .6 is iosediandin a closedposii- The temperature control unit l8 may be of any suitable construction. For purposes of illustration it may be of the type shown in the Patent 2,303,011, issued November 24, 1942, to which reference may be had for a detailed account of its construction and mode of operation. In general it comprises a temperature control unit operable to regulate the flow of gas to the main burner H in response to temperature changes on a bulb 3| disposed in a conventional manner in an oven (not shown) and connected to the temperature control unit |8 by a capillary tube 32 so that a preselected temperature may be maintained in the oven. The temperature control unit l8 also includes a shut-off valve which controls the flow of gas to the oven burner The shut-off valve is under the control of a control knob 33 extending through a manifold cover plate 34 to be accessible at the front of the range. Normally the knob 33 is biased to an outward position and must be depressed slightly before it may be rotated to open the shut-01f valve and preset the temperature control mechanism.

The safety valve l6 may be of any suitable type. For purposes of illustration itis of the electromagnetic type as shown in my copending application, Serial No. 642,941, filed January 23. 1946, to which reference may be had for construction details and its mode of operation. Suffice it to say, herein, that the safety valve I6 is normally biased to a closed position and is opened by a timer mechanism 36 actuated by actuation of' the control knob 33. Associated with the safety valve I6 is a thermocouple 31: mounted adjacent the oven pilot burner l9 and connected to the safety valve l6 bysuitable leads: ina conduit 38. The safety valve isarranged so that when the thermocouple 31 is heated by the oven pilot burner I9 a current is generated-in the thermocouple that is sufiicient to energize the electromagnetin the safety valve l6 and hold the safety valve in its open position.

The r-lash means-includes a horizontal tube 4| having one end supported onthe. side of. a housing 42 for the pilot burner 21'. 'Atits opposite end. the tube 4| is connected with an upper end of a; generally vertically disposed tubular sec tion 43. Thelower end of the-tubular section 43- is: supported by an inverted; funnel-shaped portion 44 forming a part of the sub-burner assembly 26 and. overlying the ports |1 of the sub-- burner assembly- The sub-burner assembly 26 is i'n communication with the oven. pilot burner I91. through av passageway 46 formed in the arm In. this instance the vertical tubular section 413 is formed. by: a pair: of U or channel-shaped members: 5|. and 52 telescoped together toform mpassageway 53 having. an. air passageway 54 extending. lengthwise of the members 51 and 52;.and. effecting. communication between atmosphere-and the central passageway 53'. As shown the member 5| includes a. bridging portion 55 and: spaced side portions 56 in parallel relationandiatsubstantially' right angles to the" bridging portion 551 The member 52 is formed by a bridging portion 5 and? spaced side portions 58 and: 53 in parallelism and at substantially right angles: to the bridging portion 51.v The side-.58 lsawiderr (see Figs. 5 and 6) than the side 59- forr'a purpose to presently'appean- The memhers-5| and 52- are dimensioned so that when they are telescopedtogether or are in anested relation (see-Fig; 2-) they forma substantially square shaped tube in'which the side 58 of the member 52 is in side by side contiguous relation with one of the sides 55 of the member 5| and the side 59 is spaced inwardly from the other side 56 and the edge 62 of the side 58 engages the bridging portion 55 and'. the edge 63 of the side 59 is in spaced relation to the bridging portion 55.

To secure the members 5| and 52 in their nested relation one side 56 and the bridging portion 55 are depressed or crimped at spaced positions indicated by the numerals 66 and 61, respectively. The crimps 66 define projections on the inwardly facing surface of one of the sides 56 dimensioned so that when the members 5| and 5-2 are telescoped together the projections abut against the sides 59 of the member 52 and maintain the side members 56 and 59 in spaced relation. The crimps 61 define projections on the inner side of the bridging portion 55 that engage the edge 53 of the side 59- to spacethe latter away from the bridging portion 55. This construction in addition to spacing the" members in a preselected manner to define the air inlet passageway 54 also provides a construction in which the sides 55 of the outer channel member 5| serve to grip the sides 58 and 53 of the inner channel member 52 when the members are in their assembled relation. The members are thus positively maintained in their nested" relation. The projections formed by the crimps 66 and 61- are. relatively narrow so that the air passageway54' is in efiect a continuous passageway extending lengthwise of the tubular is substantially square and is along e'ach v side, that the side 56' should. be spaced 5;. from the side 56 and the outer edge 63 of the side 59 should be spaced; 1 from the bridgingportion 55.

As shown in Figure 1. only the. vertical section of the. flash means is constructedas described. in the aforegoing paragraphs. tubular. portion 4| in this instance. is shown as an imperforate tube. Test experience shows that a flame may be propagated through the flash means with the tube 4| being imperforate. Where desired, however, the tube 4-| may be of' the same construction as the tubular section 431 In Figsfl, 8, 9 and 10 there is shownamodifiedl form of the tubular section 43-. In this instanceitincludes a central passageway 1| having two air entrance passageways l2- inv communication with the central passageway: The section 43 is formed in this instance by channel members 73 and 14- telescoped together as describedhereinbefore; The channel member I3 comprises" a bridging portion 16 and spaced sides H and-.the? channel member 14 comprises abridging. portion l8" and spaced sides 19. The. sides 11 are of the The horizontal aeoasaa to define the air passageways ll! on: opposite sides of the tubular section 43 to be in communication with the central passageway I l. The sides 11 and the bridging portion 16 are deformed to define crimps 8! and 82 at spaced positions therealong. The crimps 8i defineprojectionson the inwardly facing surfaces of the sides 11 shaped so that when the members 13 and 14 are telescoped together the projections engage the sides 19 and maintain the sides 1'! and 19 in spaced relation. The width of the bridging portion 18 is preferably slightly greater than the distance between projections 8] on the sides H so that the projections tend to maintain the members 13 and M in assembled relation. The crimps 82 formed on the inwardly facing portionqof the bridging portion engage the extreme outer edges 89 of the sides 79 when the members 73 and 14 are telescoped together to space the edges 80 from the bridging portion 76 as best seen in Figs. 9 and '10. I

' This construction of a flash tub provides a very rugged construction and one that is not readily damaged during assembly or servicing thereof. Also with this construction the dimensions of the air passageway 54 (Figs. 1-6) and the air passageways 12 (Figs. 7 and 9) are accurately maintained. This construction is easy to manufacture and is also easy to assemble. Any desired length offlash tube constructed inaccordance with the 'abovemay be utilized depending upon the distance that the flame is to be propagated. The channel members in this construction are in effect self-supporting in that theydo not depend upon independent means such as a mounting at each end of the section for maintaining the channel members in spaced relation. As a result manufacturing costs of this tube are relatively low.

To better understand the function of the flash means and its operation, a. description of the operation of the lighting system follows: The system. as shown in Figure 1 is in its normalposition with the oven cold and the constantly burning pilotpburner ZIburning. When the operator of the range desires to use the range, he depresses the control knob 33 and rotates it. This opens the shut-off valve'in the unit l8. Gas flows through the conduit 23, through the passageway 22 in the arm 2| to the pilot burner 19. Some of the gas flowing through the port defining the pilot burner 19 passes through the passageway 46 in the arm 2| between the ovenpilot burner 19 and the sub-burner assembly 26. Simultaneously gas flows from the heat control unit l8, through the conduit I? to the safety valve [5. The latter is in its closed position and prevents the flow of gas to the oven burner II. The auxiliary valve 25 however is in its open position and gas flows through the conduit 28 to the subburner assembly 26. Gas issuingfrom the ports 5D in the sub-burner assembly 26 entrains a certain amount of air therein and this mixture passes upwardly through the vertical section 43- of .the flash means. As the flow becomes established in the section s .air is drawn into the central passageway 53 of the section 43 through the opening 54 along the entire length of the section t3. Flow velocity upward through the section 43 is maintained low enough to be nonturbulent. been" advanced to'explain the successful operation of the present invention, throughout the entire length of the vertical section 43 thereis According to one theory which has:

the tube of increasing richness from the point adjacent the bridging portion 55, where the air passageway 54 effects communication with the central passageway 53 to the opposite wall of the passageway defined by the bridging portion 5?. According to this theory, as the gas flows through the section 43 the flow characteristics are believed to comprise a series of co-existing columns of gas within the passageway 53 which increase in richness from a column A which is practically all air to the column G which is practically the same as the very rich mixture entering the bottom of the passageway 53. The smooth interior walls of the tubular section d3 assist in maintaining the flow of gas inthe above described condition. Due to the flow characteristics of fluids, the laminar flow in the section 43 also is believed to be maintained for a considerable distance in the imperforate section H so that a number of horizontal layers which are extensions of the columns A through G of varying degrees of richness flow to the constantly' burning pilot burner 21.. One or several of these layers will be ignited by the constantly burning pilot burner 21 and the flame flashes through that layer and its corresponding column in the vertical portion down to the subburner assembly 26. According to this theory, the reason why this construction in practice has been found to provide a very dependable means of lighting the sub-burner 26 is because of the number of layers of air-gas mixtures flowing through the flash tubes 43 and M,- with at least one of the mixtures therein being of the right combustion characteristics to be ignited and flashed back to the sub-burner 28. While the foregoing theory may correctly point outwhy the present invention has proved successful forigniting the sub-burner from the top pilot burner, it is to be understood that the present invention is not restricted to this particular theory of operation concerning its successful flame propagating characteristics over a wide range of gases. Therefore, the theory outlined above is to be considered as only one possible explanation for the successful performance of the present vinvention.

Upon ignition of the sub-burner .26 a flame i flashed from the sub-burner 26 to the oven pilot burner l9 through the passageway 46. Upon ignition of the pilot burner E9 the flame being directed against the thermocouple 31' heats upthe latter.

When the knob 33 is depressed and rotated it also sets the timer mechanism 36 into operation and after a preselectedtime the safety valve I6 is opened. Gas then flows through the conduit M, the mixing tube is to the oven burner I I. As soon as the gas issues from the ports of the oven burner II it is ignited by the pilot burner l9. The timing mechanism 36 operates to hold the safety valve in its open position until the thermocouple 3'! has been heated to produce a current that energizes the electromagnet in the safety valve l6 and holds the latter in its open position.

When the safety valve 16 moves to its open position the auxiliary valve 29 is, closed and the flow of gas to the sub-burner assembly 26 is stopped, thereby effecting an extinguishment of the flame in the sub-burner assembly.

shut-off valve in the temperature control unit I8 is closed to prevent the'flow of v gas to the conduit [1, the safety valve l6 and the main burner thought to be gradation of air and as across I I and also to the conduit 23in communication changes with the pilot burner 19'. fvv'hen the flow oigas to theoven burner H and the pilot burner I9 is stopped the b'urner's'are extinguished. H V

This application is a division of my co-pending application,- Serial No. 642,941, filed January 2-3, 1946.

While I have shown several embodiments of my invention it will be understood that I donot wish to be limited thereto since many modifications may be made and I therefore contemplate by the claims to cover such modifications as fall within the true spirit and scope of my invention 1 claim:

1. A flash tube comprising a first U-'shaped member formed by a bridging portion and spaced sides, a second 'U shaped member in nested relation with the first member and fonn'ed by sides and a bridging portion in spaced relation to said bridging portion or the first member, one of said sides of said second "member being wider than the othensaid wide side being in side by side con-- tig'uous relation with one of the sides of the first member and abutting against the bridging portion of the first member, and the narrow side of said second member being in 'space'd'side by side relation with the other side of the first member and being spaced from the bridging portion of the first member, spaced means formed on one, of the members acting between said narrow side and said other side of the first member to maintain said sides in spaced relation and spaced means formed on one or the members acting between the narrow side and the bridging portion of the first member to maintain the edge of the narrow side in spaced relation to the. bridging portion of thefirst member.

2". The combination recited in claim 1 in which the' spaced means are defined by deforming one of the sides and the bridging portion of the first member at spaced positions therealohg' to define projectionsacting between the narrow side and one of the sides of the first member to maintain them in spaced relation and between the narrow side and the bridging portion of the first memher to maintain the edge of the narrow side in spaced relation to the bridging portion of the first member. j

3. A flash tube comprising a first U-shaped member formed by spaced sides and a bridging portion, one or said sidesand said bridging portion having spaced crimped portions to define projections extending inwardly of the 'U-shaped member, a second U-shaped member formed'by spaced sides and a bridging portion, one of said sides "of the second member being wider than the other, said wide side being disposed in contiguous side by side relation with the other of the sides of the first member, the narrow side of the second member being in spaced side by side relation with said on side of the first member to be engaged by the projections thereon and the edges of the narrow side engaging the projections on the bridging portion of the first member to space the narrow side from the bridging" portion or the first member.

4; A fiashtube comprising a firstHU-shaped' of the sides of the second member en'gagmgine' projections on the bridg'ing portion of the first member to space the edg's of the sides or the second member from the bridging portion of the first member.

5. A flash tube comprisinga pair of channel members each'fo'rmed with spaced sides and a bridging portion, said channel members being teiescoped together with the sides of the larger channel member overlapping the sides of the smaller channel member and the respective bridging portions in opposed spaced relation to define a central fuel passageway extending lengthwise of the channel members, one of said channel members being formed at one of its sides, at least, with spaced transverse protrusions abutting against the adjacent side of the other channel member to maintain said adjacent sides of the channel members in spaced relation between the transverse protrusions, whereby to define an air passageway between said channel sides leadingroutside the flash tube assembly, the larger channel member gripping the smaller channel member at the transverse protrusions to maintain the channel members in assembled telescoped relation, the edge of that side of the smaller channel member which is spaced from the adjacent side of the larger channel member being spaced. from the bridging-portion of the larger, channel member when the channel members are in assembled telescoped relation, whereby to define an air passageway communicating between the central fuel passageway in the flashtube assembly and said air passageway between said adjacent spaced sides of the channel members.-

G. A- fiash tube comprising a pair-of channel members each formed with spaced sides and abridgingp-crtion, said channel members being 'telesooped together with the sides of the larger channel member overlapping the sides of the smaller channel member and the respective bridging portions in opposedspaced relation to define a I central fuel passageway extending lengthwise of the channel members, the larger,

of said channel members being formed with spaced inward-ly extending protrusions at its bridging portion and at least one side abutting against the adjacent side of the smaller channelmember to maintain said adjacent side of the smaller channel member spaced from said side and bridging portions of the larger channel and defining an air passageway between the protrusions leading from outside the flash tube assembly into the central fuel passageway there-- said -protrusions also gripping the adjacent side-ofthe smaller channel member to maintain the channel members in assembled telescopedre lation;

7 A dash tubecomprising a pair of sheet metal channel members each formed with spaced sides and a bridging portion interconnecting the spaced sides, said channel members being tele'-" scoped together with the sides of'the larger chan= nelmember overlap-ping the sides of the smaller channel member and the respective bridging portions in spaced opposed relation to one an other to define acentral -fuel passageway ex-" tending lengthwise of the assembled channel members, the larger of saidchannel members at one side, at least, being formed with a plurality of inwardly-depressed portions spaced apart along itslength abutting against the adjacent side! of .thesmaller channel member to space, apart said adjacent sides of the channel members between the inwardly-depressed portions and to define air passageways between said channel member sides leading outside the flash tube assembly, said larger channel member at its bridging portion also being inwardly depressed at a plurality of portions spaced apart along its length abutting against the adjacent edge of the same side of the smaller channel member to space apart said edge of said smaller channel member side from the bridging portion of the larger channel member between the inwardly-depressed portions of the latter and to define air passageways between the bridging portion of the larger channel member and said side edge of the smaller channel member communicating between the central fuel passageway in the flash tube assembly and said passageways between the spaced sides of the channel members, said inwardlydepressed portions at the side of the larger channel member also gripping the adjacent side of the smaller channel member to maintain the channel members in assembled telescoped relation.

8. A flash tube comprising a pair of channel members each formed with spaced sides and a bridging portion, said channel members being telescoped together with the sides of the larger channel member overlapping the sides of the smaller channel member and the respective bridging portions in opposed spaced relation to define a central fuel passageway extending lengthwise of the channel members, one of said channel members being formed at both of its sides with spaced transverse protrusions abutting against the respective adjacent sides of the other channel member to maintain said adjacent sides of the channel members in spaced relation between the transverse protrusions, whereby to define air passageways between said channel sides leading outside the flash tube assembly, the larger channel member gripping the smaller channel member at the transverse protrusions to maintain the channel members in assembled telescoped relation, the edges of the sides of the smaller channel member being spaced from the bridging portion of the larger channel member when the channel members are in assembled telescoped relation, whereby to define air passageways communicating between the central fuel passageway in the flash tube assembly and said air passageways between said adjacent spaced sides of the channel members.

9. A fiash tube comprising a pair of sheet metal channel members each formed with spaced sides and a bridging portion interconnecting the spaced sides, said channel members being telesooped together with the sides of the larger channel member overlapping the sides of the smaller channel member and the respective bridging portions in spaced opposed relation to one another to define a central fuel passageway extending lengthwise of the assembled channel members, the larger of said channel members at both of its sides being formed with a plurality of inwardlydepressed portions spaced apart along its length abutting against the respective adjacent sides of the smaller channel member to space apart said adjacent sides of the channel members between said inwardly-depressed portions and to define air passageways between said channel member sides leading outside the flash tube assembly, said larger channel member at its bridging portion also being inwardly depressed at a plurality of portions spaced apart along its length abutting against the adjacent edges of the sides of the smaller channel member to space apart said edges of said smaller channel member sides from the bridging portion of the larger channel member between the inwardly-depressed portions of the latter and to define air passageways between the bridging portion of the larger channel member and said side edges of the smaller channel member communicating between the central fuel passageway in the flash tube assembly and said passageways between the spaced sides of the channel members, said inwardly-depressed portions at the sides of the larger channel member also gripping the adjacent sides of the smaller channel member to maintain the channel members in assembled telescoped relation.

PETER I. HOLLMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Gauger Aug. 8, 1950

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