US2476870A - Geared rheostat control for oil burners - Google Patents

Description

July 19, 1949. M. D. HUSTON 2,476,870

GEARED RHEOSTAT CONTROL FOR OIL BURNERS Filed Nov. 16, 1944 2 Sheets-Sheet 1 0000000000000 000000 00000000 0000000000000 QQOOOOOOOOOOQGIQO i 7 WWI 5y PJ M/b Jflorieeys.

July 19, 1949. M. D. HUSTON GEARED RHEOSTAT CONTROL FOR OIL BURNERS 2 Sheets-Sheet 2 Filed Nov. 16, 1944 J7? were for M70250]? J 17am #0)? y Rain M Patented July 19, 1949 2,475,870 GEARED RHEOSTAT CONTROL FOB OIL BURNER Milton D. Huston, Santa Fe, N. Mex., assignor, by mesne assignments, to Breese Burners, Ino., Sante Fe, N. Men, a corporation of Delaware Application November 16, 1944, Serial No. 563,755 8 Claims. (01. 137-21) My invention relates to an improvement in controls and has for one purpose to provide a control device for combustion units, such as liquid fuel burners.

Another purpose is to provide control means for controlling the flow of liquid fuel and of air to a liquid fuel burner.

Another purpose is to provide means for supplying an excess flow of air at the starting period,

for warming up the burner.

Other purposes will appear from time to time in the course of the specification and claims.

I illustrate my invention more or less diagrammatically in the accompanying drawings wherein:

Figure 1 is a vertical section through a burner illustrating my control in side elevation; I

Figure 2 is a side elevation of the control, on an enlarged scale, with parts broken away and parts in section;

Figure 3 is a section on the line 3-3 of Fi ure 2;

Figure 4 is a vertical section on an enlarged scale through the control portion proper;

Figure 5 is a section on the line 5-5 of Figure 4;

Figure 6 is a section on the line 5-6 of F1!- ure 2; and

Figure 7 is a view similar to Figure 6 of a variant arrangement of locking slot.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings i generally indicates an outer housing or drum the upper portion 2 of which may serve as a combustion chamber and heat radiating member. The drum is shown with legs 3 separated by air inlet spaces 4. 5 is a bottom partition centrally apertured as at 6. I is a fan-motor mounted on any suitable support 8 which may be secured to the bottom of the plate 5. 9 is a fan driven by the motor. ill is a pot having an upper flange ll resting on an angle ring l2 extending inwardly from the drum. is is a centrally apertured combustion ring. The pot I is shown as having a plurality of primary air inlets 14 located at various levels. I indicates a row of secondary air inlet apertures near the top of the pot. I6 is the bottom of the pot. Liquid fuel may be delivered to the pot bottom along the duct l1 extending from any suitable float valve assembly it. The details of the float valve assembly as such do not of themselves form part of the present invention and need not be exhaustively described. I! is any suitable liquid fuel supply duct controlled by a valve structure not herein shown in detail, which may be operated by any suitable float 23 in response to the level of fuel within the float valve assembly. 21 is any suitable safety float, operating the lever 22. 23 is a top plate or cover for the float valve assembly. The rate of flow of liquid fuel along the duct ll may be controlled by any suitable valve the details of which are not herein shown.

25 indicates an exterior manually operable knob for said valve. The rate of flow through the valve may also be independently controlled by an operating button 2G which may be actuated by a control lever 21. The lever 21 is shown as pivoted by forked lugs 23, which pass through apertures in an arcuate housing 23, having a gap 29a in its generally cylindrical wall. The op posite side of the housing is slotted as at 30 to permit the operating end II of the lever 21 to extend therethrough. The slot 33 is shown as having a lower locking portion 32 with an upper ledge 33. When the lever 21 is moved into position to operate the button 23 to reduce the flow of fuel to the pilot range, its end 3| may be moved laterally, as shown in dotted line at Ila in Figure 6, to lock against the ledge 33. Thus regardless of the setting of the knob 25, the valvewhich controls the flow of liquid fuel along the duct I1 is thereby set at the minimum or pilot flow. Mounted upon the housing 23, which serves as its support, is a rheostat housing generally indicated at 40, with its cylindrical side wall provided with air inlet or ventilating apertures M. It carries on its upper face the rheostat control knob 42 which in turn controls the rheostat contact spring arm 43 which operates against any suitable rheostat resistance 44. It will be understood that the rheostat resistance, through any suitable conductive circuit 45, is in circuit with the motor I and with any suitable outside source of electric current. The rheostat spring contact 43 is mounted on an insulating hub 36 which moves in unison with the knob 42. It will be understood that the knob 42 includes a pointer 53 aligned with any suitable calibration upon the top wall llia of the rheostat housing 40. As the rheostat knob 42 is rotated to move the contact 43, the hub 46 rotates the interfltting stem 41 which carries a pinion 48 in mesh with a gear 49, the pinion and gear being located beneath a plate 54 secured as at 55 to the bottom wall 40b of the rheostat housing 43. The gear 49 controls a shaft 56 having a rectangular end 51 penetrating a corresponding aperture 58 in the knob 25. It will be noted that the arcuate housing 28 is cut away to give access to the knob 25 3,. and to permit its rotation. It will be understood however that the knob 25 is controlled by the rotation of the rheostat knob 42.

Referring to the form of Figure '7, the slot 30a is provided with a lower side notch 32a and an upper side notch 32b. In connection with the use of such a slot it is desirable to mount the lever 21, or its equivalent, in such fashion as to give it lateral thrust to the left, referring to the positio of the parts in which they appear in Figure '1. In that event the end 3") of the lever will be held in whichever of the slots 32a or 32b it may be aligned with, preventing accidental displacement.

It will be realized that, whereas, I have described and illustrated a practical and operative device, nevertheless many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention. I therefore wish my description and drawings to be taken as in a broad sense illustrative or diagrammatic, rather than as limiting me to in precise showing.

The use and operation of my invention are as follows:

My invention is applicable, as a separately added control, to standard float valve assemblies for liquid fuel burners. It is customary, in such assemblies, to have a manual operating knob for controlling or varying the rate of flow of liquid fuel from the float chamber to the burner. It is also customar to provide an independent valve control element. The first is indicated at 25 in the present drawings and the second at 26. In operating a pot type burner such as is shown in Figure l, I find it desirable, and provide means for, normallyvarying in unison the rate of air flow and the rate of fuel flow to the burner. However, in starting with a cold pot it is desirable initially to flood the pot with a substantial volume of liquid fuel and then burn off this initial suppl to heat the pot. After an adequate initial supply of fuel has been provided, and after it has been lighted and is burning off, it is desirable to maintain a maximum rate of air flow in con-. nection with a minimum rate of fuel flow. This is provided by my above described structure.

The use of the starting lever 21 permits the user to set the rheostat knob 42 for maximum booster motor speed, for the starting period, while at the same time holding the oil flow down to pilot rate, to avoid puddling while the burner is warming up. Thuswhen the starting lever 21 is positioned in the locked position indicated in dotted line at 31a in Figure 6, and regardless of the setting of the rheostat and thus of the knob 25, the depression of the button 26 is effective to maintain the flow of fuel at the minimum or pilot rate. Enough oil may be initially admitted to the pot for starting purposes by first turning the knob 42 to high. The starting lever 21 is then moved to the depressed position and, while a pilot or minimum flow of fuel is maintained, a maximum air flow is delivered, by the high setting of the knob 42. The starting lever is positive in action and eliminates any possible doubt as to the final setting of the control. If desired, the lighting instructions may be written on the rheostat dial. The starting operation is as follows. Assuming that the dial may indicate stations numbered one to six inclusive, spaced circumfercntially around the dial, the operator turns the knob to the maximum, until oil flows into the burner and then turns it back to the starting position. He then depresses the starting lever, lights the burner and returns the knob to the maximum or desired setting. After the burner is heated, the operator releases the starting lever 21, the knob 42, and thus the valve control 25, being already set at the desired position. The operator does not have to hold the starting lever in position, as the lever 21 is locked at the starting position by the ledge 33, or is locked in the offset 32a. No damage is done if the operator delays considerably in releasing the lever 21. However, when he does release it the pot, having been heated, is ready to operate at full fire. The air rate and the oil flow rate are both controlled in unison, by the knob 42, which not only controls the rheostat contact 43 but also the oil inflow control knob 25 which controls the oil inflow valve. The interposition of the pinion 48 and the gear 49 permits the use of almost a full 360 degrees of movement of the rheostat lever in connection with the variations of the oil control knob setting from minimum to maximum. It will be understood that the rheostat is so proportioned as to provide the right amount of air flow for the different settings of the fuel valve which are obtained by the rotation of the knob 25 through the above described gearing, by the rheostat knob 42. The air supply increases progressively from a minimum at the pilot setting to a maximum at the high fire setting.

Since the design and proportions of different float valve assemblies vary, in applying my control as a supplement to an existing float valve assembly I may find it desirable to vary the reduction obtained by the gearing employed, It is desirable that, regardless of the are through which the knob 25 is rotated between maximum and minimum valve setting, the control knob 42, and its pointer 50, rotate'through an arc of not much less than 360 degrees.

I claim:

1. For use with float valve assemblies having a fuel control valve and a rotatable control knob and an independent reciprocating control element, both adapted to operate said valve, a supplemental. control assembly including a rheostat resistance, a contact therefor, a manually operable control member adapted to rotate said contact and an actuating connection between said control member and said control knob, a second manually operable control member adapted to actuate said reciprocating control element, and means for looking it in a position adapted to hold said reciprocating control element at minimum fuel flow position.

2. For use with float valve assemblies having a fuel control valve and a rotatable control knob and an independent reciprocating control element, both adapted to operate said valve, a supplemental control assembly including a rheostat resistance, a contact therefor, a manually operable control member adapted to rotate said contact and an actuating connection between said control member and said control knob, and a second manually operable control member adapted to actuate said reciprocating control element, said member including a lever end, a slotted locking element through which said lever end extends, the slot in said locking element having a locking offset adapted, when the lever end is seated in said offset, to hold said second control member, and thus said reciprocating control element,,at minimum fuel flow position.

3. For use with float valve assemblies having a fuel control valve and a rotatable control knob and an independent reciprocating control element, both adapted to operate said valve, a supplemental control assembly including a rheostat resistance, a contact therefor, a, manually operable control member adapted to rotate said contact and an actuating connection between said control member and said control knob, said supplemental control assembly including a rheostat housing and a hollow, walled support therefor adapted to be secured to the top of a float valve assembly, and a second manually operable control member adapted to actuate said reciprocat S control element, said control member including a lever mounted on said hollow support.

4. For use with float valve assemblies having a fuel control valve and a rotatable control knob and an independent reciprocating control element, both adapted to operate said valve, a supplemental control assembly including a rheostat resistance. a contact therefor, a manually operable control member adapted to rotate said contact and an actuating connection between said control member and said control knob, said supplemental control assembly including a rheostat housing and a hollow, walled support therefor adapted to be secured to the top of a float valve assembly, and a second manually operable control member adapted to actuate said reciprocating control element, said control member including a lever mounted on said hollow support and having an and extending outwardly through a slot in said support.

5. For use with float valve assemblies having a fuel control valve and a rotatable control knob and an independent reciprocating control element, both adapted to operate said valve, a supplemental control assembly including a rheostat resistance, a contact therefor, a manually operable control member adapted to rotate said contact and an actuating connection between said control member and said control knob, said supplemental control assembly including a rheostat housing and a hollow, walled support therefor adapted to be secured to the top of a float valve assembly, and a second manually operable control member adapted to actuate said reciprocating control element, said control member including a lever mounted on said hollow support and having an end extending outwardly through a slot in said support, said slot having a locking oifset adapted to hold said second control member at minimum fuel flow position.

8. For use with float valve assemblies having a fuel control valve, a rotatable manually operable control knob, and an independent reciprocating valve control element, both adapted to operate said valve, a supplemental control assembly adapted to be secured as a unit to said float valve assembly, said supplemental control assembly including a rheostat resistance, a movable rheostat contact, and manually operable means for simui- 99 taneously moving the rheostat contact and said control knob in predetermined relationship, and an actuating member on said supplemental control assembly, operable independently of said manually operable means, adapted to move said reciprocating valve control element to minimum flow position, regardless of where the movable rheostat contact may be positioned in relation to the rheostat resistance.

7. For use with float valve assemblies having a fuel control valve, a rotatable control knob and an independent reciprocating control element, both adapted to operate said fuel control valve, a supplemental control assembly adapted to be secured as a unit to said float valve assembly, said supplemental assembly including a frame, a rheostat resistance on said frame, a movable rheostat contact, and a manually operable control member mounted on said frame, and adapted simultaneously to rotate said contact and said rotatable control knob, and an additional actuating member on said supplemental control assembly, operable independently of said manually operable means, adapted to move said reciprocating valve control element to minimum flow position, regardless of where the movable rheostat contact be positioned in relation to the rheostat resistance.

8. For use with float valve assemblies having a fuel control valve, a rotatable control knob and an independent reciprocating control element, both adapted to operate said fuel control valve, a supplemental control assembly adapted to be secured as a unit to said float valve assembly, said supplemental assembly including a frame, a rheostat resistance on said frame, a movable rheostat contact, and a manually operable control member mounted on said frame, and adapted simultaneously to rotate said contact and said rotatable control knob at different rates of rotation, and an additional actuating member on said supplemental control assembly, operable independently of said manually operable means, adapted to move said reciprocating valve control element to minimum flow position, regardless of where the movable rheostat contact be positioned in relation to the rheostat resistance.

MILTON D. HUBTON.

REFERENCES CITED The following references are of record in the Number Name Date ll 1,300,423 Limpp Apr. 15, 1919 1,655,246 Schermuly Jan. 8, 1929 2,041,241 Goldfield May 19, 1980 2,207,821 Robinson July 16, 1940 2,269,248 Breese Jan. 6, 1949 2,269,778 Schueder Jan. 6, 1942 2,372,438 Landon Mar. 27, 194i

Images