US2741904A

US2741904A - Flame snuffer for wick-burners

Info

Publication number: US2741904A
Application number: US215971A
Authority: US
Inventors: Allen M Stelle; Paul K Beemer; Henry O Fuchs
Original assignee: Preco LLC
Current assignee: Preco LLC
Priority date: 1949-11-07
Filing date: 1951-03-16
Publication date: 1956-04-17
Anticipated expiration: 1973-04-17

Description

A ril 17, 1956 A. M. STELLE ET AL FLAME SNUFFER FOR WICK-BURNERS Original Filed Nov. 7, 1949 2 Sheets-Sheet l I i l I' l l I I 64 1 ii 1 ,LJ I 1 i ALLEN M. JTELLE,

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IN VEN TORS.

ATTORNEYS- April 17, 1956 A. M. STELLE ET AL 2,741,904

FLAME SNUFFER FOR WICK-BURNERS Original Filed Nov. '7, 1949 2 Sheets-Sheet 2 h 4 7 .54- 4% hiya 22? 55 W8? w 47 A44 2 I 53 "56 46 #12 523K: ('21 47 ALLEN M. 575445,

24 W 3' HENRY QFZCHS,

FLAME SNUFFER FOR WICK-BURNERS Allen M. Stelle, San Marino, Paul K. Beemenl'asadena, and Henry 0. Fuchs, Los Angeles, Calif., assignors to Preco Incorporated, Los Angeles, Calif., a corporation of California a Original application November 7, 1949, Serial No. 125,944. Divided and this application March 16, .1951, Serial No. 215,971 I 4 Claims. cr- 67--78) The present invention relates generally to flame snuffers, and is more particularly concerned with snuffers adapted for regulating and snuffing the flame from wick burners.

This application is a division of our'co-pending application entitled Thermostatically Controlled Heater, filed November 7, 1949, Serial Number 125,944, now Patent No. 2,717,590, issued September 13, 1955.

Thoughnot so limited, the invention is particularly Well adapted for use in connection with the thermostatic control of wick-flames t heaters such as are described in said co-pending applicationtha't is, heaters which find widespread use in the field of heating produce-containing railroad cars and trucks. Such heaters are exposed to very severe service conditions and yet it is highly important that they function effectively over long periods of unattended useas fully set forth'in said co-pending application.

Accordingly, it is necessary that every element and unit of the heaters be dependable and quickly responsive to changing temperature conditions, and this includes the flame regulators and snufferswhich necessarily play an essential part in thethermostatic control of the heater burners. t

It is therefore an important object of the present invention to provide a snufferwhich is exceptionally sturdy and yet is relatively delicate in response -that is, of a nature to respond quickly and surely when relatively slightly changing temperature conditions demand its operative movement. Q

It is a further object of the invention to provide a strong, light-weight flame regulator and snulfer which is of simple construction and easy of fabrication.

As a furtherfeature of the invention, one embodiment; thereof incorporates a guard which is adapted to function effectively to prevent drafts fromaccidentally extinguishing the pilot flame of the burner. Other objects and features of theinvention will be made apparent from the following detailed description, reference being had to accompanying drawings, in which:

Fig. 1 is a medial section, partlyin broken-away elevation, of our improved snuflFer, in an association with a thermostatic control device and a wick-burner;

Fig. ,2 is a section on y it shows a control crank arm and its operating rodirnoved to positions other than those they occupy inFig'. 1; i

. Fig. 3 is an exploded view of a portion of a snap' over spring assembly which may be incoporated in the device;

Fig. 4 is a fragmentary medial section showing a variational form of burner cartridge and flame-regulating and snufling member; and

Fig. 5 is a section on line 5-5 of Fig. 4. v

As stated in the introduction, the invention is particularlywell adapted to use in connection with heaters and thermostatic control devices such as are set forth respec tively in said copending application (wherein claims to the heater, as a whole, are to be found and our co-pending application entitled Thermostatic Control Unit, filed line 24 of Fig. 1, exceptthat 2 March 16,1951, Serial No. 215,972. We will therefore describe the present invention in such environment, but it will'be understood this is not to be considered as limitative. t

A fragment of the dome of a heater is indicated at 12, this dome supporting the horizontally spaced, vertical tubes 24 and 60. A burner unit 23 is supported in tube 24 and a thermostatic control unit A is supported in tube 60. Burner unit 23 comprises arnetal jacket 27 which retains a central pilot burner wick 2S and a surrounding, annular, main burner wick 29. The wicks may be made of any suitable non-charrable material such as glass fibre or equivalent substance presenting suitable capillary passageways.

Pilot wick 28 is contained within a wick-tube 36 which terminates in a substantially conical pilot burner tip or dome 41 with a central orifice 44.

. The flame regulator or snuffer is generally indicated at C and includes an annulus 46 having a down-turned, outer peripheral flange 47, or, more generally, a centrallyapertured and upwardly dished, circular plate. The annulus is pivotally mounted at 47 on a control arm 48 of inverted channel cross-section. The arm, in turn, has pivotal mounting on shaft 49 which is fixed with relation to burner unit 23, the location of the shaft being more definitely established later 011..

Annulus 46 is supported byarm 48 so bore 50 is in axial alinementwith pilot burner tip 41, the bore being of a diameter to take that tip, with suitable working clearance, when the snuffer is vertically reciprocated. In the unextinguishedeven though the snuffer be down. When a temperature drop subsequently causes arm 48 to elevate annulus 46, the upper end of Wick 29 is re-exposed and the fuel fed to the main burner is re-ignited by the pilot flame. In its upper position, the extinguisher 46 acts as a hood spaced above the main burner and serves, among other things, efficiently to spread and divert the main burner flame and the heat generated thereby.

It is desirable that the vertical space between the main burner and the outer periphery of annulus 46, acting as a hood, be substantially uniform when the main burner is in operation, so the delivery from the annular combustion mouth Slmay be uniform throughout its full peripheral extent. This is accomplished by providing for the pivotal mounting of annulus 46 on arm 48 and by hanging the annulus withits center of mass below the pivot point. The pivotal mounting also allows annulus 46 to self adjust itself to an even seating on flange 33. While this pivotal connection may be of any suitable type, we have here shown an arrangement particularly well adapted to the purpose both from the standpoint of fabrication and operation. Vertical ears 52 are struck up from the annulus 46 immediately adjacent bore 50 and are then bent flame-regulator for main burner 29, though the showing anddescription of this means is not to be considered as limitative.

Unit A includes a housing generally indicated at 67;

made up of cylindrical jacket 68 (Figs. 1 and 2) and the generally rectangular shell 69 which is in the form of an 1nverted channel member having a top wall or web 71) and vertical side walls or flanges 71. Side walls 71 have segmental horizontal flanges 72 welded at 73 to jacket 63, and it is these walls which support pivot-shaft 49, previously spoken of, whereby arm 48 is mounted for swinging movement. Walls 71 extend chordally beyond jacket (Fig. 2) and are connected at one side of the jacket by the end wall 74 which is arcuate as viewed in plan, the lower edge of wall 74 having a struck-up ear 75 to act as an arm stop.

The lowermost end of tube 68 houses a bi-metallic, coiled-band type of thermostatic element 84, having the resilient qualities usual to such elements. The inner end of the coil is operatively connected to actuating rod 85, while the outer end of the coil is connected to jacket 68 at 87. The upper end of rod has universal joint connection 97 with a rotatable disk 99 carried, in turn, by top wall 70. Disk 99 is rotatable about point 99a (Fig. 2) and the joint connection 97 is eccentrically located with respect to this point. Disk 99 is manually rotated by handle 16''! connected thereto at 185, Fig. 1.

The formation of that portion of arm 48 which lies within housing 69 will now be described. The arm is there widened, its edges being downwardly turned to provide flanges 114 which fit, with working clearance, between the housing walls 71. Pivot shaft 49 passes through those flanges. The widened portion 115 of the arm is centrally cut away to form

arms

116 and 117 connected at their ends by cross bar 118, a counterweight 119 being screwed to the latter. Housing car 75 is positioned beneath counterweight 119 to act as a stop limiting the counterclockwise movement of arm 48, as viewed in Fig. 1, and thus establishing the height to which snutfer 46 is elevated above the main burner when the latter is in full operation. Weight 119 substantially counterbalances the longer portion of arm 48 and the snuffer annulus 46, rendering the snuffer substantially non responsive to vertical acceleration.

Ears

120 and 121 are similar except that ear 121 is pierced to receive one end of link 123. They are struck upwardly from

arms

116 and 117, respectively, the ears being substantially in vertical alinement with pivot 49 when arm 48 is exactly horizontal. Ear 120 serves as a stop for arm under a shut-off setting of handle 107, as will appear, while car 121 functions as a crank arm in the operative connection between rod 85 and arm 48.

Secured to red 85 at a point above arm 48, is crank arm 122 whose distal end is connected to crank arm 121 by link or connecting rod 123. The point of pivotal connection 124 between crank 121 and connecting rod 123 lies substantially in the vertical axial plane of pivot 49 when arm 48 is exactly horizontal. Rotation of disk 99 swings the upper end of rod 35 through the arc 122a (Fig. 2). This sets up pivotal movement of crank 122 about the point of its connection to link 122, and, when this movement is in a clockwise direction (Fig. 2) cranklug 125 finally engages arm lug 120 to positively hold arm 48 and snutfer 46 down.

In considering the showing of Fig. 2, it is to be remembered that, as stated in the brief description of the figure, rod 85 is shown as shifted to a position of regulation other than that it occupies in Fig. 1, for with rod 85 in the position of Fig. 1, crank 122, as viewed in plan, is normal to the axis of arm 48.

Though not essential to the operation of the above described mechanism and therefore not to be considered as limitative on the invention, it is sometimes of advantage to provide means for snapping arm 48 to fully elevated or fully depressed positions as pivot point 124 passes through the vertical axial plane of pivot 49 during actuation of crank 122 by thermostatic rotation of rod 85 under certain circumstances. We have devised a particularly efiicient and simple snap-over mechanism for this purpose. A formation adapted to function as a snapspring anchor, fixed with respect to housing 69, is illustrated in detached aspect in Fig. 3 and is generally indicated at 126. This anchor includes arms 127 connected by bridge 128 and from one of which arms there extends a member 129 having an attachment tab 130 extended through housing-top 70 as at 131. Arms 127 are notched at 132 to take pivot shaft 49, said shaft acting to support the anchor. Bridge 128 is pierced at 133 to receive the tab 134 of snap-over, loop-spring 135 which, in Fig. 3, is shown in unstressed condition. The tab 136 at the other end of the spring loop is adapted to be engaged with car 137 punched down from the web portion of channeled arm 48.

Spring 135 is installed in stressed condition as shown in Fig. l, functioning resiliently to hold arm 48 either in the full line or dotted line position of that figure. The reaction of coil 84 to changing temperature conditions builds up forces which finally become of sufiicient magnitude to overcome the opposing force of spring 135; and the arm 48 with its annulus 46 is snapped from full line position to dotted line position, or vice versa. Shaft 49 is stationary and does not swing with arm 48; so that the pressure of member 126 against it does not impede the arm action.

It will first be assumed that snap-over spring 135 is omitted from the assembly. It will be noted that, with the upper end of rod 85 fixed against translation, a rising temperature applied to thermostatic coil 84 causes that coil to uncoil or tend to uncoil, thus rotating or tending to rotate, rod 85 and crank arm 122 in a counterclockwise direction (Fig. 2) thrusting on connecting rod 123 and crank arm 121 in a manner tending to swing arm 43 in a clockwise direction from the full line position of Fig. 1 to the dotted line position to lower the snutfer. On the other hand, a decreasing temperature applied to coil 84 acts reversely, that is, it tends to swing arm 48 in a counterclockwise direction to raise the snuffer.

It will have been predetermined that, with the thermostatic coil 84 in equilibrium, and the upper end of rod 85 held against translation, it requires a rise or fall of a given number of degrees or a fraction of a degree in temperature to rotate rod 85 about its axis sufliciently to swing arm 48 from either the full line or the dotted line position to a midway position. We will call this predetermined extent of rise or fall in temperature the operating differential.

If the snap-over spring 135 be installed after the device has been adjusted and calibrated, it will, of course, prevent the arm 48 and annulus 46 from dwelling in equilibrium positions, that is, positions mid-way between the full and. dotted line positions of Fig. 1. Since the thermostatic coil 84 must overcome the force of spring 135 in order to actuate the snuffer, the value of the operating differential will be slightly increased. On the other hand, the snap-over action has the advantage of preventing the arm 48 from hovering in equilibrium condition and thus from being susceptible to extraneous forces which might otherwise cause undesirable snuffer-movement.

The pilot tip 41 described in connection with the embodiment so far discussed is for the purpose of protecting the pilot flame from drafts when the main burner flame is extinguished. However, such a protection is not always necessary, or it may be provided by other shielding means, carried, for instance by the annulus 46. We have shown such means in Figs. 4 and 5. It will be observed that in this embodiment the pilot wick is merely that portion of the main burner wick which directly underlies the annulus bore 50 when the snulfer annulus is in extinguishing position.

Burner cartridge 23b is made up of a cylindrical jacket 27b containing wicking 29b. The central, circular portion 28b of the wicking, which portion directly underlies the bore 50 of annulus 46, acts as the pilot wick of the assembly. It will be seen that this pilot flame area is circumferentially defined by the wall of bore 50 and the flame therefrom will not be extinguished by reciprocation of the and extending diametrically across bore 50 and in a plane normal to the axis of arm 41%. The plate is cut away at 222 to allow for the passage of fork arms 56. The cut outs also permit relative pivotal movement between arms We claim:

v 1. In a flame extinguisher for burners, an annulus having a central through bore, upstanding ears on the annulus at diametrically opposite sides of the annulus bore, a pivotally supported arm, a fork on said arm and spanningethe annulus bore, and pivotal-connections between the fork and said ears.

'2. In a flame extinguisher for burners, an annulus having a central through bore, and a flat plate arranged on edge and normal to the plane or and secured to the annulus, said plate extending diametrically across the annulus bore.

3. A flame extinguisher as in claim 2, wherein a portion of said plate extends axially through the annulus bore.

56 and annulus 46, but the extent of such movement is 1 limited by the oppositely projecting, horizontal stops 223 'struck from plate 220 above arms 56. These stops, in

their coaction with arms 56 prevent theaccidental tilting of the annulus to an extent which might otherwise cause the annulus to catch in or dig into the wick material 2%.

It will be noted that the plate portion 224 extends downwardly through bore 50 to a point in close proximity with wick 2% when the annulus is in snufling position, while the upper part of the plate extends well above annulus 46, thus serving as a draft-shield which protects at least half of the pilot flame when the annulus is fully depressed at least as to drafts which are in or approximately in a direction normal to the plane of the plate. The arms 56 serve as partial pilot-flame shields against'drafts coming in from other directions.

Whileewe have shown and described preferred embodiments of our invention, various changes in design, structure and arrangement may be made without departing from the spirit and scope of the appended claims.

4 In a flame extinguisher for burners, a supporting member, an arm pivotally mounted on said supporting member, an annulus having a central through bore, said annulus being pivotally mounted on said arm, a plate normal to the plane of and secured'to the annulus, said plate extendingacross the annulus bore, and means on said plate limiting'the, pivotal movementof the annulus with respect to the arm.

References Cited in the file of this patent