US2313554A - Fuel control for oil burners - Google Patents

Description

D. F. JONES FUEL CONTROL FOR OIL 4BunNERs Filed Jan. 1e, 1940 2 sheets-sheet 1 March 9, 1943.

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. 4FUEL CONTRL FOR OIL BURNERS l Filed Jan. is, 1940 2 sheets-sheet u INVENTOR F/. 4 .O0/V F JUA/"5 ATTORNEY.

Patented Mar. 9, 1943 UNITE .STATES OFFICE FUEL CONTROL FOR OIL BURNERS ration of Michigan Application January 18, 1940, Serial No. 314,429

3 Claims.

This invention relates to fuel controls for oil burning heaters and more particularly to the mechanism for operating such controls.

Itis customary to locate the fuel control which includes the metering valve for an oil burning heater at the rear and adjacent the bottom thereof in order to position it near the burner and also to make it as inconspicuous as possible. That location has the disadvantage that it renders the control rather inaccessible when it becomes necessary to regulate the flow of fuel to the burner. In order to overcome this diliiculty, various attempts have been made to operate the control from above or at the front of the heater by means of an extension shaft or other remote control device connected to the stem of the metering valve. Such efforts have not been entirely successful because of the excessive lost motion or back lash in the'extension shaft which prevents the position of the handle or dial from accurately indicating the position of the metering valve. Furthermore, the cost of previous devices of this type has been relatively great. A still further objection to previous constructions on this order has been that they are prone to develop rattles and squeaks in service.

Accordingly, the principal object of this invention is to provide a remote control device which has little or no lost motion between the operating handle or knob and the metering valve stem. Another object is to provide such a device which is simple, inexpensive and easily fabricated and assembled. Another object of the invention is the provision of a remote control mechanism for a fuel control which is resiliently supported in order to prevent rattles and squeaks from developing.

These objects will more fully appear in the following specication, reference being made to the accompanying drawings, wherein- Figure 1 is a side elevational view of an oil burning heater of the circulating type embodying this invention;

Figure 2 is a fragmentary cross-sectional View of the heater showing the remote control devicev in more detail;

Figure 3 is a fragmentary side elevational view of the structure shown in Figure 2;

Figure 4 is a fragmentary top plan view of the structure shown in Figures Zand 3;

Figure 5 is a fragmentary front elevational View of the heater showing the operating knob or handle and the indicating dial surrounding the same; and

Figure 6 is a top plan view of the oil control itself.

Briey, the invention comprises an extension device for the stem of the metering valve in the fuel control. The extension device includes a rotatable control knob having its axis of rotation at an angle (in this case'90 degrees) to the axis of the Valve stem. The control knob is connected to the valve stem by a pair of straight rigid rods and a flexible shaft. One rod is aligned with the axis of the knob. The other rod is aligned with the axis of the stem. The flexible shaft is interposed between the tWo rods and has its opposite ends axially aligned with the adjacent rod. Novel means are provided for maintaining the parts in aligned position and for preventing lost motion betweenk the parts.

Referring now more specifically to the drawings, Figure 1 illustrates a heater I0 of the socalled circulating type having an outer casing II. Supported within the casing II is an inner shell I2, shown in dotted lines, which forms the combustion chamber for the burnerand air jacket surrounding an oil burner I3.

A fuel control Ill is secured by means of a bracket I5 to the back wall of the casing II. The control I4 is connected by conduit I6 to the oil burner I3 and by another conduit I1 to a suitable supply tank, not shown. The control I4 is conventional and includes a rotatable and vertically movable valve having a valve stem I8 which projects through the top of the control. Rigidly attached to the valve stem I8 is a cam ring I9 having a cam surface 20 which rides on a lug 2I on the top of the housing of the control I4. A handle Ia is rigidly secured to the upper end of the valve stem I8. The handle Ia is normally provided for operating the control when no extension shaft is employed. Rotation of the valve stem I8 causes the cam I3 to raise or lower the stem IS relative to its seat to admit more or less fuel to the burner.

A knob 22 for rotating the Valve stem I8 is mounted at the front of the casing I I and is connected'by means of an extension shaft assembly 23 to the valve stem I8. Suitably inscribed on the front casing of the panel is a dial 24 which corresponds with a dial 25 on the fuel control I4 to indicate the different settings of the valve in the fuel control Ill. Y

The extension shaft assembly 23 comprises a exible shaft 26, the opposite ends of which are axially aligned with the valve stem I 8 and the knob 22. Surrounding the shaft'26 is a tubular shroud 21. This shroud is substantially rigid and is nearly but not quite as long as the flexible shaft 23. The internal diameter of the shroud 21 is slightly greater than the diameter of the shaft 26, the difference in diameter being just enough to permit the shaft 26 to turn freely within the shroud 21. Preferably this shroud 21 is bent to shape before connection to the other parts of the assembly 23.

A rigid rod 28 is axially aligned with and attached securely at one end to the flexible shaft 26 and at its other end to the knob 22. Preferably the shaft 26 is provided with a noncircular extension 29 which lits within a recess in the adjacent end of the rod 28. Thev other end of the rod 28 seats in a socket 30 in the knob 22 and is held in place therein by means of a set screw 3|. The diameter of the rod 28 is substantially the same as the diameter of the shroud 21. Y

A sleeve 32 is slipped over the joint between the rod 23 and the adjacent end of the shroud 21 and ts relatively snugly thereover. It 'will be noted from the drawing that the sleeve 32 overlaps a substantial portion of both rod 23 andrshroud 21 and thereby maintains the adjacent ends of the latter in alignment at all times.

Theother end of the shaft 25 and the upper end of the handle Ita are connected together by a second rigid rod 33 axially aligned therewith. rIhe upper end of the rod 33 has a socket which receives a non-circular extension 34 on the adjacent end of the shaft 26. The parts 25 and 33 are assembled so that there is a slight space left between the adjacent ends of the shroud 21 and the rod 33. The lower end of the rod 33 is flattened at 35 and projects through an opening in the top of the handle lea. The rod is held in the handle ISa Vby means of a split pin 36 which projects through land aids in maintaining the rod 33 in alignment with the valve stem'i. The slot 4| is formed in this particular shape in order to permit the assembly 23 to be inserted into Vthe bracket 'from the side.

wTh'e extension shaft assembly 23 passes through a vertically elongated slot 42 in the back wall of the casing Il. The slot is elongated to permit some up and down motion of the assembly 23, particularly the shroud 21 and sleeve 32 as the valve stem i8 moves up or down under the actionof the cam I9. In order to prevent unnecessary movement of the assembly, and thereby minimize rattling thereof in the slot, a spring 3 is provided. One end of the` spring is coiled around the rod 28 and abuts the front end of the sleeve 32. The other end of the spring d3 has a loo-p 45 which is hooked into a pair of apertures `lll-l in the back wall of the casing ii.

a force which has components in each of the three directions mentioned and maintains the assembly 23 in a taut condition. In other words, it prevents relativeaxialmovement of the parts at the joints, as Well as axial and lateral motion of the hcrizontalparts 'of the assembly.

When the knob 22 is turned the movable parts (28, 23 and 33) of the extension shaft assembly cause the rotation of the valve stem I8, and consequently raise and lower the valve stem from its seat by means of the cam i9 acting on the lug 2|. During this rotation the shroud 21 prevents twisting or warping of the flexible shaft 2S and thus overcomes any possible back lash caused by such warping or twisting. At the same time the sleeve 32 maintains the rod 28 and adjacent end of the flexible shaft 26 in alignment, and in that way any lost motion due to relative displacement of those parts is eliminated. Relative displacement of the ends of thevrods 33 and the adjacent end of the flexible shaft 25 is substantially eliminated by means of the angle bracket 31 which holds the rod 33 against lateral motion in all directions except toward the casing II.

The spring 43 prevents movement of the assembly toward the casing. There is a slight bending between rthe two parts 26 and 33 at the joint between them in order to allow the valve stern I8 to move vertically. This bending, however, is very slight, and the amount of back lash or lost motion caused thereby is negligible.

The construction is relatively inexpensiveV because cf the short length of flexible shaft which is used. inasmuch as exible shafts of this type are relatively expensive, the less used the cheaper the construction can be made. Instead of a long flexible shaft, rigid rods'28 and y33 are employed for most of the distance between the valve stem I8 and the knob 22.

The structure above described is easily assembled. The shroud 21 is preformed, or in other words, bent to shape before assembly with the other parts. VRods 2B and 33 are' easily connected to the flexible shaft 23 by means of the particular joints employed. Furthermore, the entire assembly 23 may be connected Atogether as a unit, one end passed through the casing, the rod 33h1- serted in the slot'42 in bracket'38, and the ends of the assembly connected to the knob 22 and valve stem handle Ira. Finally, the spring 43 is hooked into the holes 44.

From the foregoing it vwill be apparent that this invention provides for remote control of the metering valve and eliminates the lost motion normally occurring between the metering device and the control knob. TheV entire construction is relatively inexpensive and is quiet in operation.

The scope of the invention uis indicated in the appended claims.

I claim:

l. Mechanism for transmitting rotary motion from a driving member to a driven member having non-aligned axes through a support interposed between said mernberswhich 4comprises two spaced apart rigid rods adapted to be connected at their ends vremote from-eachV other to the respective members, a flexible shaft connected at its ends to the adjacent ends of the rods, a rigid shroudrsubstant-ially coeXtensive With and surrounding the flexible shaft, means for maintaining one of said rods and the adjacent end of the shroud in alignment, and resilient means engaging said mechanisrnand said supporting means for biasing both of said 'rods'both axially and radially.

2. Mechanism for transmitting rotary motion from a driving member toa-driven-member having non-aligned axes through a ysupport interposed between said members, which comprises two spaced apart rigid rods adapted tobe connected at their ends remote from each other to the respective members, a ilexible shaft connected at its ends to the adjacent ends of the rods, a rigid shroud substantially coeXtensive With and surrounding the flexible shaft, means for maintaining one of said rods and the adjacent end of the shroud in alignment, and resilient means engaging said mechanism and said supporting means for biasing both of said rods axially.

3. Mechanism for transmitting rotary motion from a driving member to a driven member having non-aligned axes through a support interposed between said members, Which comprises two spaced apart rigid rods adapted to be connected at their ends remote from each other to the respective members, a flexible shaft connected at its ends to the adjacent ends of the rods, a rigid shroud substantially coextensive With and surrounding the flexible shaft, means for maintaining one of said rods and the adjacent end of the shroud in alignment, and resilient means engaging said mechanism and said supporting means for biasing both of said rods radially.

DON F. JONES.

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