US1926254A - Safety device for boilers - Google Patents

Description

Sept. 12, 1933. F.- L. BADGETT 1,926,254

SAFETY DEVICE FOR BILERS Filed June 8. 1951 2 sheets-sheet 1 INVENTOR ATTORNEY Sept. 12, 1933- F, BADGE-f1 1,926,254

SAFETY DEVICE FOR BOILERS Filed June 8, 1931 2 sheets-sheet 2 /f ivy@ 4.

@j lNv'ENToR ATTORNEY Patented Sept. 12, 1933 UNITED STATES SAFETY DEVICE FOR BOILERS Fred Lee Badgett, Chickasha, Okla., assignor to Badgett Steam Lubricator Company, Chickasha, Okla., a corporation of Oklahoma Application June s, 1931. serial No. 542,846'

4 Claims. (Cl. 137-144)` My invention relates to automaticheat-control apparatus and more particularly to a safety device for boilers, the principal object of the invention `being to provide apparatus `of this character forv automatically cuttingoff the supply of fuel and draft to a boiler` when thewater level inthe boiler reaches a-dangerously low,y

Fig. 1 is a perspectiveview of aboiler equippedwith fuel and draft control mechanism embodying my invention.

Fig. 2 is a plan view of va thermostat assembly, parts thereof being shown in A. central section to more clearly disclose lthe structure of the device. x

Fig. 3 is a rear elevational View of the thermo-Y stat assembly; b

Fig. 4 is a cross section on the line 4 4, Fig. 2.

Fig. 5 is an elevational viewof a fuel anddraft control, the greater portion of the device being shown in central vertical section to illustrate the operation vof the valves.

Fig. 6 is a plan View of the fuel and draft control unit.

Fig. 7 isa cross sectionV of the-line 7 7, Fig. 5.

Referring more in .detail to the drawings:

1 designates a boiler including a re box 2, a steam dome 3 and a smoke stack `4.

The mechanism for controlling the supply of r fuel to the re box of the boiler, and the supply of draft to the stack, comprises a thermostat assembly 5 anda control unit 6, each of which will now be described in detail.

. The thermostatassembly is mounted adjacent one side of the boiler slightly below the ,waterA level thereof Vwith the front end of the thermo-b stat at a lower elevation than therear end, as shown in Fig. l of the drawings, and comprises a supporting plate 7 having an opening 8 near its approximate center for slidably receiving a thermostat tube 9` mounted inspaced relation Within a casing l0 and retained in concentric sliding relation therewith by inwardly extending guide bosses 11 fixed in the casing by means such as welding, as indicated at 12.

Fixed to the rear end of the casing, preferably by Welding, are supporting bolts 13 adapted to extend through a series of openings 14 surrounding the opening 8 in the supporting plate. Adjusting nuts 15 threaded on thebolts and engaging opposite faces of the plate are provided for varying the inclination of the casing and thermostat with relation to the supporting plate and boiler. `The opposite end of the casing is externally threaded, as shown at 16, forengag'ing the Yinternal threads 17 ofY a reducer coupling 18 having an intermediate web 19 provided with an` internally threaded vopening 20 for receiving the forward end of the thermostat tube. 65.

In this manner the front end of the thermostatremains fixed while its opposite end is free to slide through the opening 8 of the lsupportingplate when vexpandedbor contracted dueto variations of temperature. Ventilating ports 2l are provided in the casing to permit circulation of air around the outer surface of the thermostat. f

The end of the supporting platenearest'the opening 8 is provided with an opening 22 for 75- receiving Vthe nipple, 23 of a valve housing 24 secured to the plate by a nut 25 threaded on the nipple and engaging .theplate An annular seat 26 is provided in the valve housing., for cooperatingwith the conical end 27 80* ofl a valveustem 28 extending through a con-l centric opening 29 in the nipple and retained-` insealed slidingV relation with the nipple `by packing material 30 seated in acounterbored opening 3l of the nipple and urged into engage 85 ment Vwith the stem by a gland 32.

The opposite end .of the supporting plate is provided with a series of spaced openings 33 for selectively receiving a fulcrum rod 34 yieldingly and adjustably retained in the plate by a spring` 35 mounted on the rod between inner and outer bearing washers 36, and byadjustingnuts 37 and 38 threaded on the rod and respectively engaging the front face of the supporting platey and the outer bearing washer. 9

v A bearing head 39, .having a relatively wide slot4 40 for receiving aV leverarm 4l, is threaded on the rear end of the fulcrumfrod and is fixed thereto by a jam nut 42V. y

A longitudinal series `of openings 43 is provided in the lever arm for selectively aligning with the transverse openings in the bearing head, a headed pin 45 being extended through the arm and bearing head and secured thereto by a cotter pin 46. Y

Threaded on the free end of the thermostat tube is a similar bearing head 47 including an inner enlarged end 48 provided on its upper face with an inlet opening 49 for lreceiving a steam line communicating with the tube. The

of the coupling 18 lis aconduit 55'leading intov the sideof the boiler, as shown at 56, and pro-v vided with a valve 57 and with a drain 58, a drop 59 being formed inthe line to serve as a trap for preventing hot water in the line 55 adjacent the boiler from working through the cooler water in said line adjacent the thermostat. f. l y

The fuel and draft control unit 6 is operated by the thermostat assembly and includes a valve 60 interposed in a fuel supply line 61 leading toa burner (not shown) inside the fire box, and a valve 62 is interposed in a line 63 leading from the steam dome of the boiler to a blower 64 extending into the stack 4.

Each of the valves is provided with-the usual neck 65, the Aneck of the valve 60 extending through an opening 66 formed in a supporting plate 67 adjacent one end thereofand the neck of the valve 62 extendingrthrough analigning opening 68. Clamping nuts 69 are threaded on each -of thel stems into engagement with the supporting bar for securing the valves to the bar.

Provided in the housing 60 is an inwardly directed flange 70 having a conical seat 71 for cooperating with a valve 72 including `a yguide 73 slidably extending through the seat yopening. A valve stem 74 secured to the valve extends through' a concentric opening 75 of the neck and is maintained in sealed sliding relation therewith by packing 76 urged into a counterbored opening 77 of the neck by a gland 78.r

Spaced bracket armsy 79 formed integrally with the clamping nut 69 of the valve 60 are joined at their upper ends by a cup 80 having a concentric opening .8l for receiving ay guide 82 formed integrally with the upper end of a bearing head 83, said head being threaded on" the upper end of the valve stem 74 and maintained in-adjustedrelation therewith by a lock nut 84 threaded on the stem.`

A slot V85 in the head 83 includes a lower wall 86 having a knife edge 87 serving as a bearing surface for a lever arm 88`extended into the slot and limited in its upward movement by a cross pin Y89 inserted through transverse aligning openings 90 of the head.

The structure of the yvalve 62, with the exception of being smaller in size, is preferably identical to vthe valve 60 and includes a stem 91, projecting'through a packing gland 92 provided on the outer end of the neck 65, and having an upper threaded end93 for receiving a bearing head 94 locked on the stem by a jam nut 95.

Provided adjacent the opposite end of the supporting vplate is an opening 96 for adjustably receiving a fulorum rod 97 threaded throughout its greater portion so that a spring 98 may be mounted on the stemvon the lowei` side of the supporting bar between bearing washers 99 and j retained thereon inadjusted position by a nut 100,-a similar adjusting nut 101 being threaded on the stem against the opposite or upper face of the bar.

A` bearing vhead 102 similar to the head 94 is threaded on the extreme upper end of the rod 97 and locked thereon by a jam nut 103, and each of the heads 94 and 102 are provided with relatively Wide slots 104 for receiving the lever arm 88, transverse pins 10.5 and 106 being extended through the respective heads and through the bar for pivotally connecting the bar to the heads.

From the foregoing it will be apparent that the operation of the valves is dependent upon each other and that means for closing the larger valve would serve to close the smaller valve. This actuating means is preferably provided on the larger valve and includes a cylinder y107 threaded into the upwardly directed opening 108 of the cup member 80 and adapted to receive a piston 109 comprising a `pair of opposing cup lmembers 110 clamped by a nut 111 against the head 112 of a bolt 113.

yIn order to yieldingly urge the piston to its uppermost'position under normal conditions a spring-114 is mounted in the cup member with` its upper end bearing against a retaining washer 115 anchored tolthe guide portion 82 of the head 83 by a bolt 116 adjustably secured to the guide by a nut 117.

Threaded into an opening 118 formed in the upper end of the' cylinder is a steam `line -119 leading into the lower opening of the valve housing 24 of the thermostat assembly. From the upper end of this valve a conduit 120 leads into the top end ofthe boiler and is provided with a valve 121 and with a-*T-fitting 122 from which a branch 123 leads to the inlet opening 49 of the thermostat. A T-i'ltting 124 is also provided in the line 119 forfreceiving a branch pipe 125 provided with a relief valve 126.

The operation of av boiler equipped-with a thermostat assembly and with a fuel control unit constructed and assembled as described would be as follows: 4

As long as the water level in the boiler is maintained at a proper height the entire thermostat tube, or a sufficient portion thereof, will be lled with water to cause contraction of the tube which, in turn, closes the valve 24. This .position of the valve 24 prevents pressure of Y steam in the line from being exerted on the piston in the cylinder 107 and, consequently,-the valves 60 and 62 remain in open position to permit uninterrupted supply of fuel to the burner-in the fire box of the boiler and a continuous supply of steam to the blower in the stack 4.

Should the water level in the boiler reach a dangerously low mark, the water in the thermostat tube will recede and a greater portion of the tube will be filled with steam from the line 120 which will cause expansion of the tube and consequent openingof the valve 24.

With the valve 24 in this position steam from the line 120 is free to flow through the line 119 to depress the piston 109 in its cylinder against tension of the spring 114. This downward movement of the piston will close each of the Yvalves 60 and 62, thereby preventing admission of fuel to the fire box of the boiler and supply ings for receiving said neck portions, meansV for securing said neck portions to the bar, valves in the housings having stems, a lever anchored to the bar and operatively connected with the stems, and pressure-responsive means for actuating said lever to simultaneously operate the valves.

2. Apparatus of the character described including a valve housing having a neck portion a support having an opening for receiving said neck portion, a nut for'clamping the neck porv pressure-responsive means including a cylinder carried by .the nut and a piston slidable in the cylinder and operatively connected with the valve stern for `actuating said valve, a second valve mounted on the support having a stem, a lever having one end anchored to the support and its opposite end Aconnected With the first named stem, and means operatively connecting the stem of the second valve with the lever to eiect operation of the second valve simultan-- eously with actuation of the first named Valve.

4. Apparatus of the character described including a pair of valves having stems, a support for the valves, a bearing head on one stem having a transverse slot, a wall in said slot having a knife edge, a lever anchored tothe support and extended through said head for bearing engagement with said knife edge, means for operatively connecting the lever with the other valve stem, and pressure-responsive means for actuating thelever to operate the Valves.

FRED LEE BADGETT.

Images