US1716244A - Automatic fuel cut-off - Google Patents

Description

June 4, 1929. SAGER 1,716,244

AUTOMATIC FUEL CUT-OFF Filed Dec. 23, 1926 3 Sheets-Sheet 1 June 4, 1929. G. r A. SAGER AUTOMAT I C FUEL CUT -OFF Filed Dec. 23, 1926 3 Sheets-Sheet ahuznto'c June 4, 1929. G. A. SAGER AUTOMATIC FUEL CUT-OFF Filed Dec. 23, 1926 5 Sheets-Sheet 5 iii Patented June 4, 1929.

UNITED STATES GEORGE A. SAG-ER, OF ALBANY, NEW YORK.

AUTOMATIC FUEL CUT-OFF.

Application filed December 23, 1928.

This invention relates to an improved automatic safety liquid fuel cut oil especially designed for use in connection with furnaecs or the like employing an air blast to maintain combustion of the fuel, and seeks, among other objects, to provide a device which will, serve not only to greatly reduce lireainl accident hazards but will also, by preventing waste, as tor inst-nice when a burner is unintentioimlly extinguished, efiloct a marked conservation. of the fuel.

The invention seeks, as a further object, to provide a. device which will dependably 'ltuiction to cut off the supply of incl to the jliurnacc upon failure of the air blast or an appreciable drop in the pressure thereof.

A 'Iiurlher object of the ii'iveiition to provide a device which, after having functioned to cut oil' the fuel supply, will. maintain said supply cut off until the device is manually reset, even though the blast pressnre of the air supply should, in the meantime, he resumed.

And the invention seeks, as a still further object, to provide a device adapted for installation in shops or the like in coi'inectiim with the fuel supply lines of the shop furnaces for reducing lire l'iazari'ls.

Other objects of the invention not specifically mentioned in the foregoing will appear during the course of the following description.

In the accompanying drawin s:

Figure l i a vertical. longitucmal sectional view througg h my improved cut oil.

Figure 2 isa transverse sectional view on the line 2-2 of Figure 1, looking in the direction indicated by the arrows, and particularly slmwing the air escape passages of the pressure chamber.

Figure 3 is a transverse sectional view on the line 33 of Figure 1, looking in the direction imlicated by the arrows, and particularly showing the fuel valve.

Figure l a schematic view showing the useof the cut oil in conjunction with the fuel supply lines and furnaces of a shop.

lfigure 5 is a detail elemtion showing a typical installation of one of the cut o'l'l's at one of the tliurnaces.

Figure (3 is a. fragmentary perspective View showing a. portion of one of the pilot lines as emlnnlicd in a tire preventative system using my in'iprovcd cut ofll. a tire alarm box being also illustrated.

Serial No. 156,691.

Figure 7 is a detail. sectional view particularly showing the mounting of the fusible or inflammable closure employed at the month of each of the bleeders.

Figure 8 is a. detail vertical sectional view through the the alarm box shown in Figure 6.

Figure 9 is a detail sectional view showing a typical check valve employed.

l igure 10 a detail sectional view showing a typical strainer employed, and

Figure 11 is a detail sectional View showing the automatic cut oil for the blower motor employed.

In carrying the invention into effect, I employ a valve casing 10 having an inlet 11 and an outlet 19., and formed in the casing at its outer end is a valve chamber 13 from the inner end of which leads a passage 14 connecting the inlet with the outlet. At the junction of the chamber 13 with the passage 14 is a valve seat 16, and slidable in said passage to cooperate with said seat is a fuel valve 17 which may be of the single seat or of the double seat balanced type depending on the size of the unit in which it employed. At its outer end the valve is provided with an axial stud 18. Closing the chamber 13 at its outer end is a plug 13) screwed into said chamber, and fitting at one end in said plug is a spring 20, the op posite end of which engages over the stud 18 of the fuel valve for normally holding the valve closed. As will be appreciated, the inlet 11 may, if desired, be suitably closed, and an inlet pipe connected in the outer end of the valve chamber 13 in lieu of the plug 1). Slidable through the inner end portion of the casing 10 axially thereof a push rod 21 which projects into the passage 14 to abut the inner end of the valve 17, and I preferably provide, at the inner end of the casing, a packing gland 22 for the rod, although, in some instances, said. gland may be eliminated. Adjustable upon the inner end of the casing is a gland cap 23.

Mounted upon the inner end of the. easing a spider 24, the arms of which are connected, at their inner ends by a sleeve 25 screwed over the inner end. of the casing, and connecting said arms at their outer ends is a ring 26. Seating at its periphery against said ring is a diapl'uagm 27, preferably of leather or other suitable flexible material, and fixed to the outer side of said diaphragm is a preferably galvanized sheet metal circular back plate 28 reinforcing the diaphragm throughout the greater portion of its area. The plate 28 is of less diameter than the diaphragm and overlying the diatightly binding the diaphragm between said- A pressure chamber 3t 15.

flange and ring. thus defined at the inner side of the diaphragm and attention is now directed to the fact that the construction of the diaphragm is such that the force exerted on the push rod 21 by the diaphragm will be dependent on the pressure in the chamber at and, within certain limits, not dependent on the position of the diaphragm. As will later appear, the effective area of the diaphragm must bear a relation to the tension of the spring 20 and to the area of the valve 17 which will depend both on the blast pressure normally employed and upon the fuel pressure.

Formed on the cap 31 near its periphery is an air inlet 35, and snugly fitting through said cap axially thereof cylindrical valve casing 36 in which is provided, as seen in Figure 2, a spider 37 defining a plurality of air escape passages or ports 38, the spider being formed with. an axial socket 39 open at its inner end. Encircling the valve casing 36 near the inner end thereof is a flange 4O seating against the cap, and extending through said flange are cap bolts ell rigidly securing the valve casing in position. However, if desired, the valve casing may be formed integrally with the cap 31. Formed on the valve casing at its inner end is a valve seat 42, and slidable through a suitable bore at the outer end of the socket 239 is a valve stem 48, to the inner end of which is fixed an air escape valve la: to cooperate with said seat. Pinned to the inner end of the valve stem is a bushing 4:5 slidable in the inner end of the socket 39, and housed in said socket to act against such bushing a spring 46 normally holding the valve open. However, should the device be mounted so that the valve was disposed in a vertical. position, the valve may be opened by ity. Detachably fixed to the outer end of the valve stem is a preferably conical knob at? and, as will be observed, the length of the valve casing 36 is such that, when the valve 4-1- is open, the knob lies within the lines of the casing so as to be housed and protected by the casing. The valve a l must be of such size that the minimum blast pressure employed in any particular installation will be suflicient to retain the valve closed againstthe action of the spring l6 so that the exact dimensions of this valve will, therefore, be dictated by conditions of use. Furthermore, the ports or passages 38 must be of suilicient size to prevent apprecia'ble air pressure being established in the chamber 8% when the valve open and, as will be seen, by employing the tapered knob 47, it will be rendered ditlicult to engage an object or instrument with said knob and prop the valve 4% closed.

In use, the inlet 35 is connected to the supply line conducting air under pressure to the burner of the furnace or the like so that the blast pressure in said supply line will, when the valve 4st is closed, also exist in the chamber 34. The fuel inlet 11 is suitably connected with the source of fuel supply while provision is made for conducting the fuel from the outlet 12 to the burner so that, as will be perceived, the fuel valve 17 is interposed in the fuel supply line of the burner. To set the device, the knob 47 is grasped and the valve llmanually closed. The valve is then held closed until. the air pressure in the chamber builds up sutliciently to overcome the tension of the spring 46 and maintain the valve closed. As the air pressure in the chamber then reaches the pressure existing in the air supply line, the diaphragm 27 is distended against the push rod 21, with the result that said rod is shifted longitudinally for opening the valve 17 against the tension of the spring 20 as well as the pressure of the fuel in the chamber 13. The fuel is then, of course, permitted to flow past the valve 17 to the burner as long as the valve 44 remains closed. However, should the pressure in the air supply line fail or drop toan appreciable extent, the air pressure in the chamber 34 will, of course, be correspondingly diminished, with the result that the spring &6 will immediately function to open the valve 44:. Thus, the air pressure against the diaphragm 27 will be relieved, and the spring 20 will. instantly function to shift the valve 17 to closed position so that the supply of fuel to the burner will be automatically cut off. As will be observed, the combined area of the ports or passages 38 is much greater than the area of the inlet 35 of the chamber 34L so that even should the air pressure in. the air supply line be resumed, or should said pressure, after having dropped, be again built up to normal, a pressure cannot be created in said chamber suilicient to distend the diaphragm against the tension of the fuel valve spring 20. Accordingly, the fuel valve will remain closed until the device is manually reset.

In Figures t and 5 of the drawings, I have shown the use.of thecut oil in conjunction with the fuel and air supply lines of the furnaces of a shop or the like. A number of conventional furnaces are indicated at i8 and the air blast supply line of said furnaces at 41-5), air being forced under pressure through the supply line 4:9 by a suitable blower 5O operated, by an apprqniate motor 51. A main fuel. supply tank is indicated at This tanlt, as is usual, is buried below the ground level, and connecteiil to one end of the tank is a pipe through Wllhll air, under pressure, is introduced into the tank for ilorcing the liquid fuel to the furiiaccs. Leading from the o iposite end of the tank to the furnaces is a fuel. supply line 54:, and interposed. in said supply line near the tank is one of the cut oils, indicated as a whole at Connected with the air blast supply line 4:9 is a pilot pipe 56 which cX- tends within the shop and leads to the cut off 35 for coinlucting air under pressure to the air pressure chamber of said. cut oil. Thus, after said cut oil has been manually set in the manner previously described, the fuel. valve thereof will, as long; as the operating pressure in the supply line 4-1-9 is maintained, be held open to permit a flow of fuel, through the fuel siupply line 5 and. as will be perceived, the cut off t) provides a inasttu' or primary cut oil controlling the supply of fuel to all of the furnarcs. .llxtcndiup, from the pipe 56, at suitably spaced points within the shop, are any ap n'opriate number of branch pipes or blecders 5'7, these blecders being located adjacent the furnaces at one side of the shop. Leading from the blast supply line 419 is anotl'ier pilot pipe 58 from which extends an appro n'iate number of blccders 59 like the blecders 57, the bleedcrs 59 being; located adjacmit the fin-nines at the other side of the shop. Screwed on the lower end of each of the bleeders, as shown in detail in Figure 7, is a head (30 seating a fusible or inflammable closi'u'e (31, which may be a cclluloii'l disc, and tightly securing; said closure in position is a clamping ring 62 screwed on "the head. As many of the pilot pipes and bleedcrs may, of course, be employed as desircd, and as shown in Figure 6, the pilot pipes may be arranged to extend along; the

ails of the building' while the bleeders may be disposed to project within the shop from said walls. in Figures 6 and 8 of the drawings I have also shown a blcedcr (33 in con- TIOPl iON with a fire alarm box (34;. be fire alarm box and the alarm mechanism may be of any conventional construction but for the purposes of the present invention, said box is provide l at the front thereof with a frangible closure pane (35. In the instance shown, the blecder (35-3 extends into the box at the top thereof and provided at its lower end with an elbow 66 in the mouth of which fitted a yieldable gasket 67 forming an air tight joint with the closure pane 65.

Leading to the burners of the furnaces 48, from tlie fuel sui ply line 54;, as shown .in Figure 4, are fuel supply pipes ('38 and, as typically shown in Figure 5, one of the cut oil's, iiulical'ed as a whole at (39, is interposed in each of these pipes to provide a secondary cut off for each ii'urnace, a manually adjustable fuel regulating valve Tl) ber 1d cut oil and the ing employed between s furnace burner. Leudinp from the air supply line hi to each of the furnaces is a blast euipply pipe 71 in which interposciil a manually adjustable blast regulating gate 72, and leading from each of the pipes Tl to the air pressure clunnber of th associated cut off 69 is a pipe 73 supplying air, at supply line pressure, lo said chamber. Thus, after the cut offs 69 have been set, the fuel valves thereof will be held open to permit a flow of fuel. to the furnace burners. However, should the air pressure in the supply line 4L9 drop or disappear, the cut o'lfs 69 will, as will be well understood in view of the foregoing description, immediately 'fllllCillOl'l to automatically cut off the supply of fuel to the furnaces.

In conjunction with the motor 51. I GU11 ploy an. automatic cut-out, best shown in Figure 11 of the drawings. This cut-out includes an insulating panel 7% on which are mounted terminals 75, and fixed to the panel, are spaced rods 76 carrying an insulating cross bar 77. Mounted. upon said rods is a head 78 closed at its open side by a diaphragm 79 which defines a ucssure chamber 80 within the head. Slidable through the cross bar 77 is a switch rod 81 carrying a switch member 82 to cooperate with the termii'ials 75, and normally holding the switch open is a spring 83. As shown in Figure 4, the terminals 75 are electrically connected with a motor starting con'ipensator 84-, which may be of any ciniyentional design so that upon the breaking of the circuit by the movement of the switch meniber 82 to open position, the compensator will be tripped for stopping the n'ioto'r. lllounted upon the panel '74 a manually operable switch 85 and, as also shown in Figure 4:, this switch is connected across the circuit of the switch terminals 75. As will be later explained this switch is utilized in starting); the motor. Leading from the pilot line 56 is a pipe 86 which is connected to the head 78, and interposed in said pipe is a check Valve indicated as a whole at 87. As shown in Figi'u'e 9, this check valve incliules a casing 88 in which is provided a valve seat 89, and ext/ nding from the easing is a side outlet 90 clos d by a plug 91. Pivoted within the casing is an arm 99., and carried by said arm is a valve disc 93 gravitating to engage the seat 89 in closed position. Formed through the Valve disc isv a small opening 94.. The function of the check valve will be later explained.

Interposed in the pilot line 56, preferably near the source thereof, is a check valve 95 like the valve 87 and interposed in the pipe 58, preferably near its source, is a like check valve 95. Arranged in advance of the valves 95 and 95 are strainers 96. As shown in detail in Figure 10, each of these strainers includes a pair of mating side plates 97 having peripheral flanges 98, and clamped between said flanges is a screen or other straining medium 99 secured by bolts 100 connecting the side plates to the strainer. The strainer is, of course, provided for filtering dirt from the air entering the pilot lines so as to prevent the pilot lines from becoming clogged.

As Will now be seen, in case of the in the shop, the air pressure in the pressure cham ber of the cut off 55 will, upon the rupture of any one of the bleeder closures 61, be immediately relieved, with the result that said out off will immediately function to stop the flow of fuel from the fuel tank through the main supply line into the shop. Accordingly, the fire hazard will be greatly reduced since the main fuel tank is, as is usual, located some distance from the shop. Coincidently, the cut offs 69 will, due to the drop in air pressure in the supply line 4-9, be caused to function so that the flow of fuel will be cut oil at each of the furnaces. Furthermore, as will be perceived, the cut off 55 will function to stop the flow of fuel to the shop when the blower is shut off and the shop is shut down and, of course, the flow of fuel will also be cut off at each of the cut offs 69.

To start the blower motor 51, the switch 85 is manually closed; As a result, the motor circuit will be closed for energizing the motor and the switch 85 is held closed until the motor has been in operation a sufiicient length. of time to build up the air pressure normally carried in the blast line 49. Accordingly, the pilot line 56 will be filled with air under pressure as will also the chamber 80 of the motor cut-out, with the result that the diaphragm 79 of said cut-out will be distended to act against the switch rod 81 and close the switch member 82. The switch 85 may then be released, when the motor circuit will be maintained closed by the pressure of air in the chamber 80 of the cut-out. However, upon failure of the motor or upon failure of the blower, with a consequent drop in air pressure in the blast line and accordingly in the pilot line and chamber 80 of the cut-out, the spring 83 will function to open the switch member 82 and stop the motor. A like result would, of course, follow in case of fire in the shop since upon the rupture of any one of the bleeder closures 61, the pressure in the pilot line, and accordingly in the chamber 80 of the cut-out, would be reduced so that the cut-out would automatically function to stop the motor.

Attention is now directed to the fact that the check valve 87 will swing open to permit a free flow of air to the chamber 80 of the motor cut-out but, upon a drop in the air pressure in the pilot line, will automatically swing to closed position to permit only a restricted flow of air out of said chan'iber through the passage 94 of the valve disc. The functioning of the cut-out will thus be delayed, in the event of rupture of any one of the bleeder closures (31, until the cut off and cut offs 69 have functioned to stop the flow of fuel to the furnaces, when the blower motor will be stopped. Otherwise, should the blower be shut down previous to the shutting off of the oil supply, oil will flow into the furnaces and cause a great deal of unnecessary smoke. The check valve 95 is arranged so as to permit a restricted flow of air into the pilot line through the passage 94; of the valve, but a free flow of air out of the pilot line, the valve disc swinging to open position under the latter condition. This arrangement of the valve is chosen so that should the source of power operating the blower motor fail, with resultant rapid stoppage of the blower, the air pressure in the pilot line will be reduced as rapidly as possible in order to actuate the mechanism for shutting off the fuel supply. The restriction of flow into the pilot line is for the purpose of preventing the blower from maintaining pressure in the pilot line after the rupture of any one of the bleeder closures 61. The check valve 95 is arranged like the check *alve 95 and performs like functions. In the instance of an extensive pilot line some time would be. required for the pressure to be reduced through the valve 95 alone. The bleeder 63 is provided in connection with the tire alarm box 64 so that when the closure pane of said box is broken for turning in an alarm, the bleeder will be opened at its mouth for liberating the air in the pilot line and consequently effecting the actuation of the mechanism for shutting off the fuel supply and stopping the blower motor. The bleeder (33 is, of course, rescaled by replacing the closure pane. If, however, delay in replacing the closure pane interferes with the operation of the shop, the bleeder may be temporarily sealed with a cork, to permit the resumption of operation.

Having thus described the invention, what I claim is:

1. The combination with a furnace, a fuel supply line leading to the furnace, an air blast supply line for the furnace, a motor,

andv a blower operated by said motor for normally maintaining a predetermined air pressure in said blast line, of a pressure controlled out off interposed in said fuel supply line, means conducting air under pressure fromv said blast line to said cut 01?, said cut oil being, autmnatically operable upon a reduction in air pressure thereto for stopping the How of fuel through said fuel supply line, means i'ncliuling an element adapted to be fused. for ventingsaid blast line and red ueing the pressure therein, a switch controlling the motor and normally held open, and means connected with said blast line and operable by said prodetm'mined air pressure for holding; the switch closed.

2. The emnbinatimi with a furnace, a fuel supply line leading to the furnace, an air blast sumply line for the furnace, a motor, and a blower operated by said motor for normally maintaining a predetermined air pressure in said blast line, of a pressure controlled cut oil interposed in said fuel supply line, means conducting. air under pressure fron'i. said blast line tosaid out off, said cut off being automatically operable upon a reduction in air pressure thereto for stopping the flow of fuel through said fuel supply line, a pilot line connected with said blast line and including an element adapted to be fused for venting said blast line and reducing the pressure therein, a switch controlling the motor and normally held open, switch. operating means connected with said pilot line and operable by said predetermined pressure in the bl. st line for nolding the switch closed, and means for retarding a reduction in the air pressure acting on said switch operating means.

The combination with a furnace, a fuel supply line leading thereto, an air blast supply line for the furnace, a motor, and a blower operated. by said. motor for normally maintaining; a predetermined air pressure in said blast line, of a pressure controlled cut off interposed in said fuel supply line, means conducting); air under pressure from said blast line to said cut off, said. out on being automatically operable upon a reduction in air pressure thereto for stopping the flow of fuel through said fuel supply line, a pilot line including an element adapted to be fused for venting said blast line and. re dueing; the pressure therein, a switch controlling the motor and normally held open, means connected with said pilot line and operable by said predetern'rined pressure in the blast line for holding the switch closed, and means interposed in the pilot line for restricting the flow of air into the plot line but operable to permita free flow of air from the pilot line into the blast line.

In testimony whereof I allix my signature GEORGE A. SAGER. 1,. s.]

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