US2746686A

US2746686A - Oven control

Info

Publication number: US2746686A
Application number: US378049A
Authority: US
Inventors: Roger S Loveland; Albert J Maher
Original assignee: Honeywell Inc
Current assignee: Honeywell Inc
Priority date: 1953-09-02
Filing date: 1953-09-02
Publication date: 1956-05-22
Anticipated expiration: 1973-05-22

Description

May 22, 1956 R. s. LovELAND Er AL 2,746,686

. OVEN CONTROL 2 Sheets-Sheet l Filed Sept. 2, 19525 May Z2, 1956 R, s. Low-:LAND ET AL OVEN CONTROL 2 Sheets-Sheet 2 Filed Sept. 2, 1955 ATTRNEY United States Patent O 2,746,686 OVEN CONTROL Application September 2, 1953, Serial No. 378,049

8 Claims. (Cl. 236-94) 'This -invention relates to combination valve and, more fspeciiically, to a combined plug valve and thermostatic `valve having ignition and signal switches cooperating with ithe valve mechanism so as to be actuated thereby. The

invention is particularly suitable for luse in the control -of gas burning ovens and provides a manually operable means for initiating the oven burner operation and adfjusting the control temperature of the oven.

One of the objects of the invention is -to provide a Y-very compact oven control valve of inexpensive construcition but having exceptional control characteristics.

Another object of the invention is to provide an oven `control, having a manually operable valve, a thermostatically Operable valve and an ignition switch, wherein the opening of the manual valve closes the ignition switch mounted on the valve and simultaneously adjusts the setting of the thermostatic Valve.

Still another object of the invention is to provide an oven control having manual and thermostatic valves, an ignition switch operable by the manual valve, and a signal switch that is adjusted by the manual valve but is actuated by the same mechanism that actuates the thermostatic valve. i

Another object of the invention is to provide a thermostatically operated Vvalve having a motion transmitting means between the valve and the movable end of a Iternperature responsive bellows that is so arranged that said free end of the bellows -is prevented from tipping or moving transversely with respect to its longitudinal axis.

Still other objects of the invention will become apparent upon reading the following detailed description of the invention in Iconjunction with the accompanying drawings wherein:

Figure l of the drawing is a cross-sectional view ofthe control along the longitudinal axis thereof;

Figure 2 is a cross-sectional view of the control taken along line 2-2 of Figure-l; i

Figure 3 is an end view of the manually operable'plug valve; 1

Figure 4 is a side elevational view of the control with the control dial removed and -with portions thereof 'broken away; A

Figure 5 is a View of the operating lever for the signal switch; and

Figure 6 is a cross-sectional view'taken along the line 6--6 of Figure 1.

As .can best be seen in Figure 1 of the drawing, the control consists of a main 'body port-ion 11 having a tapered bore 12 extending axially thereof from one end of the body, a threaded outlet opening 13 at l'the other end of the body, an inlet passage 14 extending through a thickened and hanged portion 15, at right angles to the longitudinal axis of the body, and communicating with the tapered bore 12. A gas chamber 16 is located between the tapered bore 12 and the outlet 13, into which a boss 17 extends from the sidewall of the body. The vbody has lan integral nippleportion 11a extendinglaterally from the valve body and communicating with the 2,746,686 Patented May 22, 1956 ICS 2 chamber 16 and a threaded opening 18 in the sidewall of the bodly between the Iboss 17 and ythe threaded outlet opening 13. l

A manually Operable plug 19 is positioned in the tapered bore 12 and is resilientl'y held therein by means of a coiled compression spring 20 extending between the enlarged end thereof'and a cover plate 21. The plate is clamped to the end of the body by means of bolts 22 extending through said plate and screw threaded into threaded bores 23 in flanges 11b on the control body. The plug valve has a stepped bore 24, 25 and 26 therein that communicates with a step bore 27 and 28 in a valve stem portion 19a that projects through and beyond an opening 21a in the Icover plate 21. The bores 25, 26, 27 and 28 are -concentric with the axis of the plug valve but the bore 24 is nonconcentric therewith to provide a cam surface, as can best be -seen in Figure 3 of the drawing, for a purpose to be hereinafter described. The plug valve has transversely extending passages 29, 30, and 31 which communicate with the bore 25 and :are adapted to register with the inlet passage 14 when properly positioned with respect thereto. Arcuate grooves 32 extend from .the opening 29 to the openings 30 and 31 so that gas may flow to either one of said openings or both when the portion 32 is in register with the inlet passage 14. A land portion 33 is left between the openings 30 and 31 so that when the plug valve is in the position with the land 33 over the inlet 14, no gas will flow through the plug valve to the chamber 16. In all other positions of the plug valve, gas will lbe free to ilow to sa-id chamber.

A small snap switch 3'4, having electrical terminals 34a, b, and c, and an actuating plunger 34d, as can best be seen in Figure 6 of the drawing, is pivotally mounted on the end of the body by means of a pin 35 extending -into a groove 36 formed in the Outer surface of one of the walls of `the switch body. The switch -is adapted to be rocked about a pivot 35 by means of a crank arm 37 eccentric with respect to a shaft 38 rotatable in a socket in the end of the body 11. The arm 37 is adapted to lbe swung through an arc by means of a screw driver engaging a slot in the end thereof, for adjusting the position and distance of the actuating plunger 34d of the switch from a resilient actuating arm 39 secured at one of its ends to the yswitch body. The free end of the arm 39 has a detent portion 39a that is adapted to engage in`a groove 40 -formed in a necked-down portion of the valve stem 19a for t-he purpose of adjusting the switch with respect to the plug valves so that when `the plug valve is rotated from its o position, where the detent engages :the groove 40, to an on position, the'arm 39 will actuate the plunger to close the `contacts (not shown) in the switch. The termin-als of the switch are for connection, through lead lines (not shown), to a conventional ignition means for `the gas burner to vbe controlled 'byV this control device, in any suitable and conventional manner. The switch may also be used to operate' an indicator signal. 'It will thus .be seen that upon turning the plug valve to a position which supplies gas to the burner, a circuit will be cl-osed to the igniting means for the burner to assure proper ignition of the gas. The switch 34 is retained in its assembled position with respect to the plug valve by means of a generally .cupshaped cap member l41 having a flanged portion 41a and having a portion thereof cut away to form an opening `4111, in alignment with a portion of the opening 21a in the cover plate 21, and a side opening 41C, the outturned edge 41d of which bears against the side of the snap switch with a bearing washer 42 therebetween. The cup-shaped cap member `4l has a central aperture y 43 `therein through which stem 19a extends. The membei" 41 is also' dimple-d outwardly at 44 to form a socket 3V into which an arm 4S of a latch member 46 may engage to latch the plug valve in its off position. The member 46 is a cup-shaped member having an axial opening47 in the c'losed end thereof. The above mentioned arm 45 is preferably formed 'by cutting and bending outwardly a portion of the inner end of the member 46. It also has an outwardly and radially extending arm 48, formed by cutting and outwardly bending an intermediate portion of the member 46, and an inwa-rdly and radially extending arm 49, similarly formed, to engage in a longitudinally extending groove 19t?, to key the member 46 to the plug valve, so that it will be axially slidable but nonrotatable with respect thereto. A coiled compression spring S extends between the closed end of the member 46 and the outer end of the valve stem 19a to resiliently hold the arm 45 in the groove formed by the struck out portion 44 when the valve is in its off position. It is therefore obvious that to turn the gas on, it is rst necessary to push the member 46 inwardly or axially of the valve stem to disengage the member 45 from the portion 44 so that the plug valve may then be rotated.

The member 46 and unthreaded stern extensions 22a on the bolts 22 extend through a large opening 51a in a wall 51 of a stove, with lthe member 46 further extending through an opening 52a and the extensions 22a further extending thro-ugh friction sleeves 52b in a stove bezel 52. A dial 53, made of plastic material or any other suitable material, has a centrally disposed sleeve member 54 rigidly secured thereto and a metal cap member 55 surrounding the outermost portion of the dial. The inner end of the sleeve member 4 has a longitudinally extending slot 54a therein which is adapted to straddle the outwardly extending arm 48 on the member 46 to provide a driving connection between the dial and the plug valve. A snap ring 56 is adapted to tit in any one of a plurality of angular grooves 57 formed in the outer surface of the member 46 to serve as a stop for the sleeve 54, to enable the edge of the dial to closely approach the bezel but not to rub against it. The dial may be readily removed from the member 46 inasmuch as its engagement therewith is a frictional one, the rotative force applied to the plug valve being substantially entirely through the arm 48 which extends through the slot 54u. Obviously, the distance of the dial from the ybezel must be sufficient to allow the dial to move the member 46 axially a sucient distance to disengage the arm 45 from portion 44.

'Screw threaded into the outlet 13 of the control `body is a valve seat member 58 that has an axial step bore 59, 60, and `61 therein and an annular groove 62 formed in the outer surface of the portion surrounding the bore i 59. Diametrically opposed bores 63 extend radially from the annular groove 62 to the bottom portion of the stepped bore portion 59. The outer stepped bore portion 61 is internally threaded for the reception of a gas conduit leading to the burner or burners, whichever the case may be. A knife-edged annular rib 64 forms a valve seat surrounding the inner end of the stepped bore portion 59 and is engaged by a generally cup-shaped disc valve 65. The valve has a closed end portion thereof extending into the bore 59 and is normally biased away from the valve seat by means of a coil compression spring 66 positioned 'between the shoulder formed by the junction of the `bore 60 and 69 and the outwardly llanged disc .portion 65a of the valve member 65 that engages the valve seat. A cup-shaped bearing member 67 has its lclosed end extending into and in abutting engagement with the closed end of the valve member 65 and is axially slidable on a guide stem 68. The guide stem has an enlarged and threaded intermediate portion 69 which is screw threaded through an internally threaded opening 70 in the boss 17. The other end of the guide stem 68 `is nonrotatably secured to a coupling .sleeve 71 by means of an inwardly flanged re-entrant sleeve 72 welded or otherwise suitably secured to the sleeve 71 and to the adjacent end of the guide stem 68. A11 abutment sleeve 73, having an outwardly extending annular tiange 73a, is axially slidable on the guide stem 68 and is resiliently biased toward the enlarged portion 69 by means of a coil spring 74 surrounding the stem 68 and extending between the re-entrant sleeve 72 and the flange 73a. The position of the abutment sleeve 73 is therefore dependent upon the axial position of the portion 69 in the boss 17.

To provide for the axial adjustment of the guide stem 63, the sleeve 71 is longitudinally slotted at 71a and receives a radially and outwardly extending pin 75a on a ball-shaped end 75b of a stepped Calibrating stem 75. The stem 75 has an enlarged outer end portion 75C forming an abutment shoulder 75d at its junction with an intermediate portion 75e. Packing 76 is adapted to be compressed tightly about the portion 75C by means of a packing nut 77 screw threaded into the bore 28 against a bear washer 78 so as to frictionally lock calibrating stem 75 in its calibrated position and to enable the guide stem 68 to be rotated `with the plug valve as the dial 53 is rotated. In this manner, the position of abutment member 73 is varied with the rotation of the plug valve for a purpose now to be described.

The valve 65 is adapted to be biased toward its closed position against the bias of its spring 66 by means of a suitable temperature sensing unit. The unit consists of a conventional bulb 79, a capillary tube 80, a bellows 81 and a motion transmitting mechanism positioned between the free movable end of the bellows and the abutment member 73 and valve 65. The bellows 31 has an annular flange 81a thereon that is sealingly clamped to the nipple 11a, with a packing washer 82 therebetween, by means of a clamping nut 83. The inner free end 81h of the bellows extends through an opening in a bimetallic compensating plate 84 that engages a yoke 85 having a bearing plate 86 thereon. Two generally L-shaped levers, of channel-shaped cross section, are pivoted together at the free end of their short legs and have bifurcated arcuate bearing ysurfaces on the outer ends of the long legs or arms of the levers which straddle and bear against flanges 73a on abutment sleeve 73 and 67a on bearing sleeve 67 engaging the valve 65. The elbows formed at the junction of the long and short legs of the lever are spaced apart and at all times are ,positioned on opposite sides of the longitudinal axis of the bellows. The angle between the long legs of the levers 87 is so arranged that expansion and contraction of the bellows 81 will cause closing and opening of the valve, respectively, the levers pivoting on the pivot 88 and the elbows staying constantly in a plane parallel to the axes of the valves and at all times bearing against the surface of the plate 86 and sliding thereover.

A signal-light, switch 89 is mounted on a bracket 90 which, in turn, is mounted on the body 11 by means of bolts 91. It is adapted to be actuated by the bellows through a pair of links 92 pivoted at one of their ends on pivot 88 and having a reduced diameter projection 92a at the other end of each that projects through holes 93a intermediate the ends of a yoke shaped lever 93 that straddles the boss 17. One end of the lever 93 has an upwardly struck pivot detent 93b that engages the side wall of the cam shaped bore 24 in the end of the plug valve while the other end of the lever 93 has a hole 93C therein which fits over the inner end of a plunger 94 and against a collar 94a formed thereon. The plunger is biased inwardly by means of a coil spring 95 to normally hold the lever 93 in engagement with the adjusting cam surface 24, the links 92 and the abutment collar 94a. The plunger 94 extends through a sealing plug 96 screw threaded into the threaded opening 18 in body 11 and into engagement with a resilient actuating arm 97 on the switch 89. As the means for mounting and Calibrating the switch 89 is similar to that for mounting and calibrating the switch 34, there will'be no detailed Vdescription thereof except to point out thatv the switch is calibrated to close when the oven temperature has reached the temperature setting of the dial.

The control is adapted to be connected to the supply pipe of the gas stove by means of a coupling plate 98 having an externally threaded nipple 99 thereon. Plate 98 has the same contour as the surface formed by the valve body 11 and the flange 15 and is sealingly clamped thereto, with a gasket 100 therebetween, by means of bolts 101. To provide clearance for a socket wrench to engage the bolts 101, the outer surface of the body 11 is recessed at 102 and 103.

The control may also be provided with a pilot gas control Valve and/or a by-pass control valve for supplying gas to a pilot burner from the gas chamber of the control and to supply a minimum gas flow to the main burner control by means of a manually adjustable valve 104, as illustrated in Figure 4 of the drawing. The valve illustrated in Figure 4 is a by-pass valve in that it can control the ow of the gas from the chamber 16, through a passage 105, extending from the chamber 16 to a bore 106 extending parallel with the main longitudinal axis of the body 11 and into a transversely extending portion llc of the body at the outlet end thereof. The valve 104 has a longitudinally extending slot 107 therein which is adapted to register with the passage 105 and'control the amount of gas ow through passage 105 to a center bore 108, extending axially into the valve 104 from the inner end thereof. Gas may flow from the interior of the valve 104 through a reduced diameter portion 106a of the bore 106 and a passage 109 extending from the bore 106a to the threaded outlet 13 of the body 11 to register with the annular groove 62, and thus communicate with the outlet 61 of the control unit. The valve 104 is sealed against gas leakage by means of packing 110 compressed tightly around the valve 104 by means of a packing nut 111 bearing against a packing washer 112. It will be noted that the valve 104 has a screw driver slot 104a that may be reached by a screw driver from the front of the stove when the dial S3 is removed. This will enable adjustment of the by-pass valve 104 to provide the desired minimum flow of gas after the unit has been installed in the stove.

A valve, indentical with the valve 104, may also be provided in the same lateral extension 11e of the body 11, in parallel relationship with the valve 104, as illustrated in Figure 6, to provide for the ow of gas from the chamber 16 of the control unit to a pilot burner (not shown). A passage, identical with the passage 105, would also have to be provided, but the passage similar to the passage 109 would be eliminated and in its place an internally threaded bore 113 would have to extend from the outer end surface of the projection llc to a bore corresponding to bore 106a. This arrangement would provide for the flow of pilot gas from the chamber 16 of the control unit to the pilot burner and for the regulation of this tlow by the valve similar to the valve 104.

Operation The control unit described above is installed in a stove by the gas supply pipe or manifold of the stove being connected to the nipple 99 and the outlet 61 connected by suitable conduit means to the main burner. The pilot outlet 113 is connected to a pilot burner through suitable conduit means, the bulb 79 is properly positioned in the oven, the temperature of which is to be controlled, the

ignition switch 34 is connected in a conventional manner To place the oven in operation, it is iirst necessary` to move the dial 53 axially inwardly to disengage the arm 45 from the latch portion 44 and then rotate it counterclockwise a short distance to bring opening 31 partly over inlet 14. This permits gas to flow to the pilot burner for ignition purposes without opening the main valve 65. Further rotation of the dial to a selected temperature setting will cause enlargement 69 to engage sleeve 73 and thereafter move it outwardly to permit the valve 65 to open. The rotation of the dial will cause rotation of the plug valve 19 from its oit position to the selected on position and will simultaneously move the guide stem 68 axially to position the abutment 73 at the necessary position to maintain the oven temperature at the setting of the dial. The rotation of the plug valve from its olf position to its on position will cause the detent 39a to cam out of the groove 40 and snap the ignition switch 34 closed. This will cause the igniter to ignite the pilot gas which in turn will ignite the main gas burner. As the oven comes up to the desired temperature setting, the fluid in the bulb 79 will expand and cause expansion of the bellows 81. Expansion of the bellows 81 will operate through the ambient temperature compensating plate 84, which warps in a direction to compensate for ambient temperature variations, and transmit the motion of the.` bellows to the levers 87, which act as a toggle mechanism to move the valve 65 to the right to cause throttling of the flange portion 65a of the valve against the valve seat. 64. Should there be further expansion of the fluid in the1 bulb and bellows, damage will not result to the bellows: or the valve inasmuch as the slidable abutment sleeve 73 and its biasing spring 74 serves as a strain release. When the bellows has expanded the amount corresponding tothe desired oven temperature, the plunger 94 will cause the signal switch 89 to close, indicating to the operator that the oven is in the desired operating condition. Further temperature settings may be made merely by rotating the dial to the various temperature setting indicated on the dial. Itis thus seen that a single control dial, besides having means to prevent the accidental turning on of the gas, operates to turn the gas on and olf, controls an ignition switch, adjusts the thermostatic control valve and adjusts the control mechanism for the signal light.

As it is obvious that other mechanical equivalents may be used in place of the specific mechanism and structural details of this invention, without departing from the spirit of the invention, it is to be understood that the scope of the invention is to be determined solely from the appendant claims.

We claim as our invention:

l. An automatic control comprising a control member movable between on and oli positions, an adjustable abutment, a pair of generally L-shaped levers including elbows between short and long arms and pivoted together at the outer ends of the short arms of the levers, the outer end of the other arm of one of said levers being in engagement with said adjustable abutment, the outer end of the other arm of the other of said levers being in engagement with said control member, the distance between said abutment and said control member being greater than the combined lengths of the short arms of said levers, and a condition-responsive and axially-expandable bellows operably engaging said elbows with the axis of the bellows therebetween in all positions of said control member.

2. An automatic control comprising a control member movable between on and oli positions, a pair vof L-shaped levers pivoted together at the outer ends of one of the arms thereof and providing irst and second pairs of substantially equal length arms and having bearing surfaces at the junctions of the arms of each lever, the outer end of the other arm of one of said levers being fixed, the outer end of the other arm of the other of said levers being in operative engagement with said control member, and a condition-responsive means operably en gaging said bearing surfaces with the axis of said means therebetween in all positions of said control member.

3. An automatic control comprising a control member movable between on and ofi positions, an adjustable abutment, a pair of generally L-shaped levers including elbows between short and long arms and pivoted together at the outer ends of the short arms of the levers, the outer end of the other arm of one of said levers being in engagement with said adjustable abutment, the outer end of the other arm ot the other of said levers being in engagement with said control mesnber, the distance between said abutment and said control member being greater than the combined lengths of the short arms of said levers, a condition-responsive and axially-expandable bellows operably engaging said elbows with the axis of the bellows therebetween in all positions of said control member, a signal switch, and means between said switch and the pivoted ends of said short arms for operating said switch when said control member is operated.

4. A combination control and signal device comprising a first manually operable control, a second control, a condition responsive means for actuating said second control, first motion transmitting means between said condition responsive means and said second control and operably contacting said first control for adjustment thereby, a third signal control, and second motion transmitting means between said condition responsive means and said third control and adjustably contacting said first control, the connections between said motion transmitting means and said first control being separate and simultaneously actuated by movement of said first control.

5. A combination control and signal device comprising a first manually operable control, a second control, a condition responsive means for actuating said second control, first motion transmitting means between said condition responsive means and said second control and operably contacting said first control for adjustment thereby, a third signal control, and second motion transmitting means between said condition responsive means and said third control and adjustably contacting said irst control, the arrangement providing simultaneous adjustment of the signal control and the automatic control when said first control is manually actuated.

6. A combination control and signal device comprising a first manually operable control, a second control, a condition responsive means for actuating said second control, first motion transmitting means between said condition responsive means and said second control and having an axially adjustable contact with said first control for adjustment thereby, a third signal control, second motion transmitting means between said condition responsive means and said third control and having a cam actuated adjustment with said first control for simultaneously adjusting the third control and when said first control is manually actuated to operate said irst control and to adjust said second control.

7. ln a control device, the combination comprising a first valve movable between a closed position and a plurality of open positions, a second valve coaxial with said first valve, condition responsive means for actuating said second valve, said means including a bellows disposed laterally of said valves and with its axis substantially normal to the axes of said valves, signal means, and means between said signal means and said condition responsive means for actuating said signal means in response to movement of said condition responsive means, said first Valve having means for separately adjusting the control point of said condition responsive means and said signal actuating means simultaneously with movement thereof.

8. In a control device, the combination comprising a tirst valve movable between a closed position and a plurality of open positions, a second valve, condition responsive means for gradually moving said second valve between a plurality of positions, signal means, means between said signal means and said condition responsive means for actuating said signal means in response to movement of said condition responsive means, cam means on said rst valve for adjusting said signal means, and means between said condition responsive means and said rst valve for adjusting said second valve, both of said adjusting means being actuated simultaneously upon moving said first valve means.

References Cited inthe file of this patent UNITED STATES PATENTS 403,162 Weber May 14, 1889 1,970,942 Payne Aug. 2l, 1934 2,037,142 Newell Apr. 14, 1936 2,233,117 Waddell Feb. 25, 1941 2,302,407 Waddell Nov. 17, 1942 2,616,661 Mills NOV. 4, 1952 2,639,352 Watson May 19, 1953