US2685919A - Retracting system for oil burners - Google Patents

Description

A 1954 R, B. PLASS ETAL 2,685,919

RETRACTING SYSTEM FOR OIL BURNERS Filed Aug. 24, 1951 J- 3 2&9 J 25 x9 INVENTORJ l v RAYMOND B-PLA33 mmwr. WINTERS ATTORNEY Patented Aug. 10, 1954 ,REVTRACTING SYSTEM FOR 01 BURNERSV Raymond B; Plass, Berkeley, and Harry K. Winters, San Francisco, Calif., assignors to Ray Oil Burner 00., San Franc of California isco, Calif.,' a corporation Application August 24, 1951, Serial No. 243,548

3 Claims. 1

This invention relates to retracting systems operable upon the shuttingdown of an oil burner to remove the oil from the burner tube and from all the conduits between the burner tip and the of a restriction in the line II creates a pressure which is higher than the pressure upon the oppo site side in the pipe leading to the burner J0. Any excessive pressure thus created is relieved shut-ofi valve. 5 through a return line [9 in which a spring actu- There are various disadvantages which result ated pressure regulating valve 20 is disposedi from permitting oil to remain in the burner tube The valve 20 is by-passed for'limited flow of oil and adjacent conduits when a burner is shut down as by a conduit illustrated at 2! in Fig. 1 or pref-. such, for example, as the continued burning of erably as shown in Fig. 2 where a valve disc is such oil in the atomizing cup and nozzle, and the l shown at 22 as having a notch or groove 23 formed undesirable viscosity of the oil'when-it cools par-- in its edge to permit the flow of limited quantity ticularly Where heavier oils of the type that must of oil even though the valve is in its closed posibe preheated are used. These and other disadtion. The groove 23 constitutesarestricted orifice vantages are Well-known inthe art and various ordinarily to be avoided in the system but is not types of oil retracting systemshave been designed l undesirable because it is of the self cleaning type and are in'use for this purpose. I being thoroughly flushed with oil each time the It is the object of the present invention to proregulating valve opens so that the accumulation vide an improved retracting system for oil burners of dirt or heavy components is avoided. Are which is simple and inexpensive in design and tractor cylinder is shown at 24 in Figs. 1 and-3 positive in operation. A further object of the inas having a piston 25 therein urged toward the vention is'to provide such a systemwhich avoids right by a spring 26 in a spring chamber 26*. the use of small orifices subject to becoming The piston 25 is self-guided by means of an-exclogged by heavy or dirty oil, and which acts tension 21 thereon engageable with the interior instantly upon the burner being shut down to of a reduced cylindrical portion or pressure champrevent delivery of further oil toward the nozzle. 25 ber 28 of the cylinder as indicated at 28. 'slots Further and more specific objects and advantages 1 such as shown at 29 may be provided in the perimof the invention and the manner in which it is eter of the extension 21 to "permit the pressure carried into practice are set forth in detail in the of oil to be exerted against substantially the following specification wherein reference is made entire surface of one side of the piston. A conto the accompanying drawings. 30 duit 30 forms a communication between the re- In the drawings: turn line I9 and the end of the interior of the Fig. 1 is a schematic view of an oil retracting cylinder 24 forming the pressure chamber 28*. system embodying the present invention, In a preferred form of the invention the conduit Fig. 2 is a fragmentary detail of a portion of a 30 connects with the bottom of the cylinder as pressur r l tin v lv whi h form a part of shown in Fig. 1 so that dirt or other solids are. l the system, and drained from the cylinder each time that the Fig. 3 is a central vertical sectional view of a piston moves to the right. At its opposite end, cylinder with a spring actuated and pressure the spring chamber 26 of the cylinder 24 is concontrolled P u Which p des the retracting .nected with the return line l9 beyond the valve action. 7 r 20 by a conduit 3| in which is included a spring In g. 1 of the drawings, a burner is schemati' pressed check valve 32, which valve is shown in cally illustrated at H! as supplied with oil through Fig. 3 as being included in the structure of the a main pipe I! and branch pipe 12. A pump l3 cylinder 24. A passage 32a is provided in the driven by a motor I 4 withdraws oil from any suitbottom of the cylinder 24 which connects the able source of supply not shown and directs it to conduit 3| with the spring chamber 26 Since the burner to. The motor is energized by an electhe passage 312 is made up of intersecting bores tric circuit including conductors shown at [5 one of which extends through the cylinder Wall, which circuit also controls a magnetically actua plug 24 closesth opening and provides access ated shut-off valve 16. A control switch I [1 in to the passage in the event that cleaning thereof this circuit serves to start the motor and open the is necessary. A draw-off conduit 33 communi valve simultaneously and conversely 'to permit cates the chamber 25* of the cylinder 24 with closing of the valve I 6 instantly when the motor the burner l6 and includes a check valve 35 which is deenergized. Y opens toward the chamber 26*, which valve 35 is The volume of flow to the burner is regulated shown in Figure 3 as being included in the strucby a reducing valve l8 which being in the nature ture of the cylinder 24.

In operation the burner is started by closing the circuit I5 to start the pump and open the valve l6. Pressure produced by valve IS in the return line I9 which, as previously stated, is higher than that on the burner side of the valve, enters the cylinder 24 and urges the piston therein toward the left against the pressure of spring 25 and. the piston remains in this leftward position as long as the burner continues to operate, any oil in the spring chamber having been forced outwardly and returned to the source ofsupply by means of the conduit 3|. When the burner is shut down as by opening of the switch it, oil pressure-inthereturn line I9 is reduced and; the spring 26 urges the piston toward the right. The oil; in the-right hand side of the cylinder escaping through line 30 and the bypass 2| which is shown as the slot 23 in Fig. 2. This tends to create a vacuum in the spring chamber 26 of the cylinder and consequently draws oil away from the burner ID and byway of and from. conduits 1.2 and 33 This oil remains in the spring chamber until. the burner isagainstarted.

One of the advantages of the present invention is: that oil pressure is provided for biasing the piston 25 against the-force of a spring 26 without passing; oil inv a continuous flow through any part of the cylinder. Thus. dirt or other solids containedby the oil are not deposited. at any point where they might interfere with the smooth operation of: movable parts. An advantage of the cylinder and piston construction illustrated in Fig; 3 results from the fact that the piston is effective throughout its-entire stroke ior performi-n-gits retracting function. Furthermore retractio n oi oil from the burner commences instantaneously upon the burner being shut 01T- because the failure of pressure in the return line is is immediately accompanied by rightward movement of the piston 25.

We-claim:

1. In an; oil burner system including a burner, api-pe; line for conducting oilto the. burner and means for feeding the oil under pressure to the burner through-said line; a shut-ofi valve in said line between the feeding means and. the burner operating to closethe line upon cessation of operation of. said feeding means, a piston cylinder,

a pressure reducing valve between the shut-01f valve and the feeding means, a piston in the cylinder dividing the same into two non-communieating chambers, spring means in one chamber constantly urging movement of the piston into the other chamber, a draw-off pipeline forming a communication conduit between the first pipe line on the burner side of said shut-off valve and said one chamber, a check valve in said draw-off line permitting flow only to said on chamber, a 1ead=off pipe line communicating with and leading from said one chamber, check valve means in said, lead-off line permitting flow only from said one chamber, means operating in said other chamber against said piston in response to pressure in. thefirstpipe line between the oil feeding means and the pressure reducing valve to move the piston into said one chamber against pressure therein opposing such movement, and means for euhausting; fluid from said other chamber when the pist'onis urged thereinto by said spring, said spring reacting upon failure of saidpressure and closing of said shut-01f valve toreversely. move the piston to retract oil from the burner through saiddrawmff pipe line.

2. The inventionaccording to claim 1; wherein thepenultimate means comprises a pipe providing a communicating line between the said other chamber and the first pipe line, and the last means comprises a pipe providing anoii leadj-ofi from said other chamber and a pressure-bleed valve in the last named pipe.

3'. The invention. according toolaimk 2, wherein the firstrlead -ofi pipe line communicates with the last named lead-off. pipe line on the side of the pressure-bleed valve remote from said other chamber.

ReferencesCited in the file of this patent UNITED STATES PATENTS Logan July 18, 1950

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