US2964049A

US2964049A - Fuel control and ignition system

Info

Publication number: US2964049A
Application number: US648401A
Authority: US
Inventors: Joseph L Deverse
Original assignee: Baso Inc
Current assignee: Baso Inc
Priority date: 1957-03-25
Filing date: 1957-03-25
Publication date: 1960-12-13
Anticipated expiration: 1977-12-13

Description

1960 J. L. DEVERSE FUEL CONTROL AND IGNITION SYSTEM 5 Sheets-Sheet 1 Filed March 25, 1957 All 1 INVENTOR. Joseph L. Deverse BY M i I Aff'ys J. L. DEVERSE FUEL CONTROL AND IGNITION SYSTEM Dec. 13, 1960 Filed March 25, 1957 5 Sheets-Sheet 2 57-4 Fae INVENTOR. Deverse Josq ah L Dec. 13, 1960 J. 1.. DEVERSE FUEL CONTROL AND IGNITION SYSTEM '5 Sheets-Sheet 4 Filed March 25, 1957 INVENTOR. Joseph L. Deverse 4 Affys Dec. 13, 1960 J DEVERSE 2,964,049

FUEL CONTROL AND IGNITION SYSTEM Filed March 25, 1957 5 Sheets-Sheet 5 IN V EN TOR.

dosa e/7 L. Deverse E! FUEL CONTROL AND roNrTroN s'YsrnM Joseph L. Deverse, Milwaukee, Wis, assignor to Base Inc., Milwaukee, Win, a corporation of Wisconsin Filed Mar. 25, 1957, Ser. No. 648,401

3 (Ilaims. (Cl. 137-66) This invention relates to improvements in fuel control and ignition systems for fluid fuel burning apparatus, and more particularly to so-called automatic systems of this i e.

For the control of gaseous fuel flow and ignition in clothes dryers and the like there has long been a need for a rather simple, safe compact control system contained within a single housing and operating to automatically ignite and control fuel flow to the main and pilot burners while at the same time affording protection against overheating, current failures, gas failure or mechanical malfunctioning.

It is therefore a general object of this invention to provide an improved control device affording the abovementioned desirable operational features for the control of fluid fuel burning equipment having main and pilot burners and having electric ignition means for said pilot burner, said device having means for sequentially energizing flow control means for the pilot burner, said electric ignition means and flow control means for the main burner.

It is another object of the present invention to provide an improved fuel control and ignition device of the class described wherein the flow control means takes the form of main and pilot burner fuel control valves and wherein there is a switch for controlling the electric ignition means, there being eleetroresponsive motor means for actuation of said valves and switch in a predetermined sequence to effect fuel flow to said pilot burner and ignition of the fuel thereat, followed by delivery of fuel to the main burner and ignition of said fuel by the flame of the burning fuel at the pilot burner.

Another object of the invention is to provide an improved fuel control and ignition device of the aforementioned character having means therein for preventing opening of the main fuel valve by the operation of the motor means until after the fuel has been successfully ignited at the pilot burner, said means also effecting closure of the main fuel valve in the event of outage of the flame at the pilot burner subsequent to disposition of said main fuel valve in open position by said motor means.

Still another object of the invention is to provide an improved fuel control and ignition device of the character described wherein the motor means includes a prime mover and cycling actuating means driven by the prime mover, there being resettable shut-off means actuated by said actuating means, said actuating means effecting disposition of said shut-off means in a shut-off position effecting deenergization of said prime mover and shut off of the fuel flow to the main and pilot burners in response to failure of the ignition means to ignite the fuel at the pilot burner after a predetermined number of unsuccessful ignition-attempting cycles of said actuating means.

Another object of the invention is to provide an improved fuel control and ignition device of the aforementioned character which is so constructed that upon successful ignition of the pilot burner, as well as upon said 2! predetermined number of unsuccessful ignition-attempting cycles of the actuating means, the circuit'to the prime mover is interrupted to prevent further cycling of said actuating means.

A more specific object of the invention is to provide an improved fuel control and ignition system of the class described having a resettable line powered safety shut-01f valve means in series in the fuel stream with resettable thermoelectrically powered safety shut-off valve means, each safety shut-off means being operable when deenergized to shut off all fuel flow to the main and pilot burners, said thermoelectrically powered means being responsive to outage of the pilot burner flame and said line powered means being in circuit with said prime mover, wherefore upon either pilot burner outage or failure of the line power to the prime mover all fuel flow is shut off.

Another specific object of the invention is to provide an improved'fuel control and ignition system of the aforementioned character having timing means in circuit with the prime mover and line powered safety shut-off valve means for establishing and interrupting the flow of line power thereto at preselected times to thereby initiate and terminate operation of the controlled fuel burning apparatus in accordance with the settings of said timing means.

Another object of the present invention is to provide in a device of the character set forth thermoelectrically powered safety shut-off means comprising a first controlling member having first and second controlling positions with respect to main and pilot burner fuel flow and a second controlling member having first and second controlling positions with respect to main burner fuel flow only, a power unit adapted to be energized by a thermoelectric generator and which comprises a movable magnet and a movable armature each of which is associated with a separate valve means whereby relative movement of said armature and magnet eifects movement of said first and second controlling members to control fuel flow to said burners.

Another object of the present invention is to provide a device of the aforementioned general characteristics which is adapted for mass production manufacture, is easily installed by non-skilled technicians, and is otherwise Welladapted for the purposes for which it was designed.

The novel features that are characteristics of the invention are set forth with particularity in the appended claims. The invention, itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood by the following description of a specific embodiment when read in connection with the accompanying drawings illustrating two forms of the invention wherein:

Figure 1 is a vertical sectional view of applicants automatic ignition and fuel control device disposed in a control system for fluid fuel burning apparatus, portions of said device and of said system being shown semi-diagrammatically;

Figure 2 is a fragmentary sectional plan view of the device taken along lines 22 of Figure 1, the disposition of the parts being that which obtains at the start of a normal cycle of the device;

Figure 3 is a view similar to Figure 2 showing the relative position of the parts just prior to the completion of a normal ignition-attempting cycle which has successfully ignited the pilot burner;

Figure 4 is a view similar to Figures 2 and 3 showing the relationship of the parts just prior to the end of a fifth unsuccessful ignition-attempting cycle;

Figure 4a is a fragmentary plan view similar to Figures 24 inclusive showing the relationship of the parts;

after five unsuccessful ignition-attempting cycles;

Figure 5 is a somewhat enlarged fragmentary perspective view of the mechanism shown in Figures 2-4a inelusive;

Figure 6 is a bar graph of one complete cycle or revolution of the cycling actuating means and illustrates the sequential operation of the cams denominated at the left-hand side of the graph;

Figure 7 is an enlarged fragmentary perspective view of the lower cam and reset assembly shown in the lower portion of Figure l;

Figure 8 is a vertical sectional view similar to Figure 1, showing a modified form of control device;

Figure 9 is a sectional plan vieW taken along the line 9-9 of Figure 8; and

Figure 10 is a fragmentary sectional plan view taken along line '1010 of Figure 8.

While the following description sets forth the operation of the improved fuel control and ignition device in controlling the fuel flow and ignition in specific gaseous fuel burning equipment such as a clothes dryer, it is to be understood that the improved device is not limited to use with this type of equipment, but is adapted for use equally well with other gaseous fuel burning equipment, for example, ranges, unit heaters, water heaters, commercial and central housing heating equipment and other types of space heaters.

Referring now to Figure 1 of the drawings, an improved unitary automatic ignition and fuel control device 5 is disposed to control the flow of fluid fuel to a main burner conventionally illustrated at 6 by controlling the flow of fuel to the main burner supply conduit 7. A pilot burner 8 is associated with the main burner 6 to ignite the latter in the usual manner. The pilot burner is supplied with fluid fuel through the conduit 9, and an electroresponsive igniter, for example a glow coil 19, is associated with the pilot burner 8.

More particularly the unitary flow control and ignition device 5 comprises an upper or operator section 11 and a lower or valve section 12. The valve section 12 comprises a casing 13 formed with a main inlet 2 and a main outlet 14, the latter receiving the main burner supply conduit 7. An auxiliary outlet 16 receives the fuel supply conduit 9 leading to the pilot burner 8. The interior of the casing 13 is formed with a pair of spaced generally

transverse partitions

13a and 13b defining an inlet chamber 17, an intermediate chamber 18, and an outlet chamber 19.

As. shown, a first annular valve seat 20 is formed in partition 13b and a second annular valve seat 21 is formed in partition 13:: said seats being serially arranged in the path of fluid fuel flowing from the inlet 2 to both the main and

pilot outlets

14 and 16. A third annular valve seat 22 surrounds the inner end of the outlet 14 and is axially aligned with valve seats 20 and 21. It is to be noted that the flow of fuel to the pilot burner does not pass through the annular valve seat 22 but does flow through the annular valve seats 20 and 21. Thus, obstruction of the fuel flow through the Valve seat 22 does not affect the fuel flow through the passage 16a and pilot outlet 16, whereas obstruction of fuel flow through either of the annular valve seats 20 and 21 obstructs the flow to both of the

outlets

14 and 16.

Flow control means, in the form of first, second and third control members or valve means 23, 24 and 25 cooperate respectively with

valve seats

20, 21 and 22. More particularly the valve means 23 comprises a valve disc or closure 26 which is biased toward closed position by a suitable coiled compression spring 28, and an electroresponsive operator means 27 which is operable to retain the valve disc 26 in open position with respect to seat 20 once the disc has been moved to that position, but is inoperable to actuate said disc to open position.

The operator means 27 may comprise a generally tubular housing means 29 which is fixed to a downwardly extending lug 30 formed on the bottom wall 4a of the :4 I upper housing 4. A generally U-shaped electromagnet 31 may be fixed within the tubular housing 29 and cooperates with an armature 33 movable to attracted and retracted relation with respect thereto and connected to the disc 26 by a stem 34 extending through one wall of said housing. The electromagnet 31 has an energizing winding 32 and is operable, when energized, to generate sufficient magnetic flux to hold armature 33 in attracted relation and the disc 26 in open position when said armature and disc are moved thereto against the bias of the spring 28. Means for simultaneously opening valve means 23 and resetting the armature 33 into engagement with the pole faces of magnet 31 will be discussed later.

The valve disc 26 and similar discs 44 and 41 discussed later are preferably formed with a central metallic section 26a, as shown in Figure 7, for engagement by the reset means in a manner to be more fully described later.

The valve means 24 which coacts with seat 21 and the valve means 25 which coacts with seat 22 as shown in Figure 1 have a spaced back-to-back serial relationship to each other. More particularly, valve means 24 and valve means 25 are linked by a resettable thermoelectrically powered electromagnetic latching or holding means 34a similar in many respects to the operator means 27 for valve means 23. More particularly, the linking means 34a comprises a tubular housing or hood member 35 which is supported in outlet chamber 19 by a pair of flat yoke-type

biasing leaf springs

36 and 37 which are attached at one end to the bottom wall 4a of the upper casing and at the other end to the opposite end walls of housing or hood member 35 to bias the latter toward an intermediate position (not shown) somewhat to the left of that shown in Figure 1.

Fixed Within the housing or hood member 35 is a generally U-shaped electromagnet or first coupling member 37a having an energizing winding or coupling means 38. A disc armature or second coupling member 39 is disposed within the housing 35 for coaction with. the magnet 37a, there being a stem 40 attached at one end to said armature and extending through one end wall of the housing 35 for connection at its other end with a. valve disc 41 cooperable with the annular valve seat 22. A coiled compression spring or first biasing means 42 surrounds the stem 40 and is interposed between the valve disc 41 and housing 35 as shown.

The valve means 24 comprises a valve stem 43 fixed to the other end of tubular housing 35 and carrying a valve disc 44 for coaction with the seat 21. It is to be noted that the armature 39 cannot be actuated from the retracted position shown in Figure 1 against the bias of spring 42 by energization of the electromagnet 37a. However, once the armature 39 has been placed in engagement with the pole faces of magnet 37a, as by movement of the tubular housing 35 to the left in Figure 1, the magnet 37a retains said armature in attracted relation against the bias of spring 42 as long as said electromagnet winding is energized.

The parts of the assembly just described are so arranged that the spring or first biasing means 42 performs the following three functions, namely, biasing armature 39 away from magnet 37a, biasing disc 41 toward a first operating position seated on the seat 22, and biasing the housing 35 toward the right as viewed in Figure 1 to thereby bias the valve disc 44 toward a first operating position seated on the seat 21. When the armature 39 is released from the electromagnet, the spring 42 effects seating of the valve disc 41 and biases the housing 35 and valve disc 44 toward the seat 21, overcoming the bias of

flat springs

36 and 37 to position said housing and disc in the shut off position shown in Figure l. 1

It might also be noted at this point that the

flat springs

36 and 37 permit movement of the housing 35 along the axis ofstems 40 and 43, such that a substantial force applied to valve disc 44 in a leftward direction as viewed in Figure 1, causes movement of said valve disc, the housing 35 and the electromagnet 37a toward the left against the bias of the spring 42 to a reset position in which the magnet is in attracted or coupled position with respect to the armature 39. The aforementioned reset.- ting movement is aided by the

flat springs

36 and 37 until the housing is in its intermediate position. However, since further leftward movement is required to effect resetting, the remainder of such movement is against the bias of

springs

36 and 37. If the electromagnet 37a is energized when in reset position, it generates an attractive force sufiicient to overcome the bias of the spring 42, so that upon removal of the leftward acting force on the valve disc 44 the

flat springs

36 and 37 return the housing 35, electromagnet 37a and valve disc 44 to the right, the aforementioned intermediate position. Since the armature is coupled or linked to the electromagnet during this movement, the valve disc 41 is unseated thereby, so that both valve discs 44 and 41 are in their second operating positions spaced from their seats by successful resetting of the linking or holding means 34a.

The upper or operator portion of the device comprises a generally rectangular casing 4 the bottom wall 40 of which is sealingly attached to the valve casing 13 as by the gasket 3. As viewed in Figure 1, the casing 4 supports, in the upper left-hand corner thereof, a stepdown transformer 45 of suitable or desired type which is operable to provide reduced voltage for purposes hereinafter appearing. An electroresponsive constant speed prime mover is shown in the form of a motor 46 also disposed within the casing 4. The motor 46 is operable when energized to revolve a shaft 47 at a constant speed. For purposes of illustration, and not intended to be in any way limiting, the motor 46 will be assumed to revolve shaft 47 at the rate of one revolution per sixty seconds.

As shown in Figure 1, the motor driven shaft 47 sealingly extends through a suitable O-ring equipped opening 3b in bottom wall 40 of the casing 4 into intermediate chamber 18, and has fixed thereon a lower cam assembly 48 which is shown in perspective in Figure 7. More particularly, the cam assembly 48 may be press-fitted upon the shaft 47 and is disposed for coaction with pivoted actuating bell-crank type lever means 51 and 52. The cam assembly 48 is formed with a lower cam actuating surface or lug 49 and an upper actuating surface 50'.

The position of the parts shown in Figure 7 is such that when cam 48 rotates in a counterclockwise direction, cam lug surface 49 is operable to engage lever arm 53 of hellcrank means 51 pivoting the latter on pin 54 to cause extension 56 at the end of lever arm 55 to engage surface 26a of valve assembly 23, moving the armature 33 of holding means 27 toward engagement with pole faces of U-shaped magnet 31. Further, rotational movement of cam assembly 48 in a counterclockwise direction causes upper cam surface 56 to engage lever arm 57 of bellcrank means 52 to rotate the latter on pin 58 and cause extension 60 of arm 59 to engage valve disc 44 and apply a leftward acting force thereon sufiicient to move the latter and housing 35 to the left to effect resetting of the releasable holding means 340 in the manner hereinbefore described. The exact sequence and duration of the engagement of cam surfaces 49 and 50 with their respective bell-crank means will be explained more fully hereinafter.

Most of the upper portion of control device 5 comprising the operating means 11 is shown in perspective in Figure 5, and the relative positions of the parts at various times in the sequential operation of the device are shown in Figures 24G. Before proceeding to a detailed description of that upper assembly, the major components thereof will be functionally identified. For example, an upper cam assembly 64 fixed on the shaft 47 coacts with a switch means 61, shown in the upper right-hand corner of Figure 2, and said switch means may be referred to as an ignition switch means. A ratchet assembly 74 coacts With upper cam assembly 64 and with

switch assemblies

62 and 63 which may be denominated motor control means.

The upper cam assembly 64 may be formed with actuating surfaces or lugs 65 and 66. As shown in perspective "View Figure 5, cam actuating surface 65 is the lower actuating surface and coacts with the ratchet assembly 74, whereas cam actuating surface 66 is the upper cam actuating surface and coacts with the ignition switch assembly 61. The igniter switch assembly 61 comprises a supporting bracket 67 fixedly mounted on casing wall 411 and insulatably supporting a pair of resilient leaves 68 and 69 which carry normally

open contacts

70 and 71 at the ends thereof. A pair of

conductors

72 and 73 are suitably connected to the terminal ends of switch leaves 70 and 71 as shown. The parts are so positioned that when cam means 64 rotates, lug 66 is operable to engage switch leaf 69 to cause

contacts

70 and 71 to become engaged to complete the circuit between

conductors

72 and 73.

As perhaps best shown in Figure 5, the ratchet assembly 74 comprises a sprocket-like member or disc 78 which is rotatable on fixed pin 75, the latter anchoring one end of a spiral spring 76 which is attached at its other end to an upstanding pin 77 which is carried by and disposed near the periphery of the sprocket disc 78 for coaction with switch assembly 63. The spring 76 normally urges the sprocket disc 78 in a counterclockwise direction.

As perhaps best shown in Figures 2-462, the sprocket disc 78 is formed with a plurality of longer radially extending peripheral teeth 79, and a plurality of shorter peripheral teeth 86. The sprocket disc 73 is also formed with a peripheral cam section 32 which has edge surfaces 81 and 118 for purposes hereinafter appearing.

Switch assembly 63 comprises a supporting bracket 63a which is fixed to casing wall 4a and insulatably supports flexible switch leaves 83 and 84 which in turn carry normally closed

contacts

85 and 86 at the ends thereof.

Conductors

67 and 88 are attached respectively to leaves 84 and 33. The pin 77 of sprocket 78 is engageable with an extension of leaf 83, and when said leaf is thus engaged as shown in Figure 2 the circuit between

conductors

87 and 88 is opened. When cam lug 65 rotates from the position of Figure '1 and engages edge surface 81 of sprocket 78, moving the latter in a clockwise direction as shown in Figure 3, the pin 77 on said sprocket is moved out of engagement with switch leaf 83, allowing said leaf to move contact 35 into circuit completing position with respect to contact 86 so that the circuit between

conductors

87 and 88 is completed for purposes hereinafter appearing.

Switch assembly 62 is actuated between circuit completing and circuit opening positions by two different actuating means, namely, by the step-by-step ratchet assembly 74 and also by the positioning of valve disc 41 in flow-permitting position after ignition of the pilot burner 8. As best shown in Figure 5, switch assembly 62 comprises a mounting bracket 89 mounted on wall 4a and which insulatably supports a pair of flexible switch leaves 90 and 91 having normally closed contacts F2 and 93 on the ends thereof.

Suitable conductors

94 and 95 are attached to switch leaves W and 91 respectiveiy such that the circuit therebetween is opened when

contacts

92 and 93 are separated and the circuit therebetween is closed upon engagement of said contacts. The contact carrying leaf 91 is formed with a depending lug 96 (shown in Figure 5) near the free end thereof for electrically insulated actuating engagement with a spring loaded bell-crank lever type pawl assembly W which shall now be described.

The assembly .97 comprises a bell-crank lever 105 which is rotatable on a fixed pin 98 and is formed with a lower arm 99 having a hooked pawl portion 161 on the terminal end thereof (as shown in Figures fi m). As will become apparent, pawl 100i coacts with teeth 80 of sprocket member 78. The lever also has an upper arm 100 which is formed with an upstanding lug 102 (as shown in Figures 1 and said lug being formed with an aperture which receives one end of tension spring 104. The other end of tension spring 104 may be fixed to pin 103 to bias the bell-crank lever in a clockwise direction when the parts are disposed as shown in Figures 2, 3 and 5. However, the relationship of pin 103, bell-crank pivot pin 98 and lug 102 of arm 1% is such that clockwise movement of arm 100 overcenter with respect to a line drawn through the axes of

pins

103 and 98, for example to the position of Figure 4, will cause the bias to be in the opposite direction, i.e., counterclockwise for purposes hereinafter appearing.

As perhaps best shown in Figures 2440:, counterclockwise rotation of the sprocket member 78 by cam lug 65 successively engaging surface 81 and teeth 79 thereof causes pawl 101 which is biased by spring 164 to suecessively engage the teeth 80, and prevent counterclock wise movement of the member 78 on disengagement of the lug 65 from said member. Continued rotation of the member 78 causes the edge surface 118 to engage the pawl 1 and move the latter and bell-crank lever 165 in a counterclockwise direction as viewed in the drawings to, in turn, cause bell-crank lever arm 99 to engage the downwardly extending lug 96 of switch leaf 91 and move the latter to the left to thereby separate normally closed

contacts

92 and 93 and open the circuit between

conductors

94 and 95.

Another means for actuating switch assembly 62 is provided by a bell-crank assembly 106 which is responsive to the position of valve member 4 1, which as will be apparent later, is responsive to ignition of fuel at the pilot burner. More particularly, the bell-crank assembly 106 comprises a rotatable shaft 107 sealingly extending through a suitable opening in the bottom wall 4a provided with an O ring seal 3a, said shaft having a lower portion 107a which is disposed within the outlet chamber 19 and an upper portion 107!) which is disposed within casing 4. As shown in Figure 5, the lower portion 107a is provided with a pair of yoke-like arms 198 and 109 having angled terminal portions 112 and 111 respectively which, as shown in Figures l4a, coact and are engageable with the back side of the valve disc 41 within the outlet chamber 19. The upper end 107b of the shaft 107 is provided with an arm 110 having an angled end portion engageable with the arm 100 of the bell-crank lever 105.

Movement of valve member 41 from closed position to the open position shown in Figure 3, transmits rotary clockwise motion to upper arm 110 of the bell-crank 106, which, by engagement with lever arm 100 of hellcrank 97 rotates the latter in a counterclockwise direction to move lower arm 99 thereof into contact opening engagement with lug 96 on switch leaf 91 and thereby

open contacts

93 and 92.

It will be noted, as shown in Figure 3, that movement of valve member 41 to the open position and the resultant counterclockwise rotation of hell crank 97 to the overcenter position of Figure 4 causes movement of the pawl 191 away from the sprocket member 78 such that it is completely free of any coaction with teeth 80. Thus, when valve 41 is moved to the position shown in Figure 3, pawl 101 and teeth 80 no longer coact to prevent return counterclockwise movement of the sprocket member 7 8 under the bias of spring 76, and as a result, said member tends to return to the position shown in Figure 2 upon opening of the valve member 41. The reason for this coaction will be apparent in the description of the operation of the device.

Means 113 is provided for manually resetting bellcrank assembly 97 from the overcenter position shown in Figures 4 and 4a to the position shown in Figures 2, 3 and 5, said means comprising a manually engageable button 114 attached to a stem 116 having a tip 117 which coacts with arm 100 of bell-crank lever assembly 97. The stem 116 slidably extends through an apertured up- 8 standing lug 133 formed on the wall 4a, and a spring 115 interposed between said lug and the button 114 biases said button outwardly. Depression of the button 114 moves the tip 117 into actuating engagement with arm to move the latter in a clockwise direction and return the latter overcenter to the position thereof shown in Figures 2, 3 and 5.

The electrical circuitry of the device will now be described with reference to Figure 1. For purposes of this specification it will be assumed that the outside electrical power for this device is a suitable source of volt alternating current 119. It will further be assumed that line conductor 120 is the hot or ungrounded side of the line and conductor 121 is the return or grounded side of the line. A line controlled switch 122 of any suitable or desired type, for example, electrically or mechanically actuated, is illustrated schematically as being interposed in conductor 120. It is to be further understood that while the illustrated alternating current circuit is completed by closing of switch 122 in rmponse to suitable time controlled means, it would be equally feasible, and it is within the purview of the present invention, to have switch 122 responsive to temperature, pressure or any other condition as suitable or desired.

As shown in Figure 1, the step-down transformer 45 has a primary winding 45a which is directly connected to line

conductors

120 and 121, and has a reduced voltage secondary winding 45b in circuit with

conductors

123 and 124 which connect the secondary to the energizing winding 32 of operator means 27 for valve assembly 23. A reduced voltage energizing circuit for the igniter glow coil 10 is connected across the

conductors

123 and 124 and comprises a conductor 73, ignition switch 61, conductor 72, coil 10, and conductor 125 connected in series. Thus, anytime time switch 122 is made and igniter switch 61 is made, the glow coil 10 heats up to a temperature suflicient to ignite fuel emanating from the pilot burner 8. If desired, a suitable ballast resistor 126 may be inserted in conductor 72 to compensate for the change in resistance in glow coil 10 when the latter becomes heated as is well understood in the art.

The prime mover or motor 46 is energized directly 011 the line by the following circuit: line conductor 120, conductor 95 leading to switch assembly 62, switch leaf 91, through

contacts

93 and 92, switch leaf 90, conductor 94 to one motor terminal, and from the other motor terminal back to return line 121 through conductor 127. Switch assembly 63 is connected in parallel circuit relationship with switch 62 by a conductor 87 which is connected to conductor 95, and conductor 88 which is connected to conductor 94. Thus, it is seen the motor 46 will be energized whenever the time controlled switch 122 and either of the motor switches 62 or 63 is closed.

The thermoelectric circuitry for winding 38 of electromagnet 37a, which is in the latching or holding means 34a between valve members 44 and 41, comprises a thermoelectric generator 128 subject to the heat of burning fuel at the pilot burner 8. One terminal of the generator 128 is grounded at 129, and the other terminal is connected, as by a conductor 130 through a suitable terminal connection 131 and conductor 132, to one end of magnet winding 38. The other end of magnet winding 38 may be suitably grounded as at 140. A suitable high limit switch is schematically indicated at 139 to interrupt the circuit to winding 38 upon the occurrence of an abnormally high temperature in the area to be heated for purposes hereinafter appearing.

Operation Assume the following initial conditions: timing switch 122 open to thereby deenergize the transformer 45 and motor 46; temperature surrounding high limit switch 139 being below that point which opens the contacts thereof; switches 61, 62 and 63 in the position shown in Figure 2, i.e. ignition switch 61 being open, motor control switch 9 62 being closed, and motor control switch 63 being open;

valve discs

26, 44 and 41 seated so that no fuel is flowing to either the main r pilot burners; thermoelectric generator 126 cold so that the winding 38 of latching or holding means 34!: is deenergized; cam actuating lugs 66, 65, 56 and 49 on shaft 47 and the members to be actuated thereby in the starting or shut-off position shown in Figures 1, 2 and 7.

To start the device into operation, the timing means 122 is set as desired, and upon closure thereof line power is delivered to

conductors

120 and 121 for a preselected period. As shown in the bar graph of Fig. 6, upon the making of switch 122, the device will start a sixty second resetting and ignition cycle, which is theperiod of time that is necessary to rotate

cams

49, 59, 65, 66, one complete revolution, said period being by way of example only, and any suitable or desired departure therefrom being within the scope of this disclosure.

The bar graph of Figure 6 is read from left to right, the cross-hatched portions thereof showing the relative angular positions of the actuating lugs 49,

t

65, 66, as well as the relative sequence and duration of the engagement of the actuating lugs with the members actuated thereby during a single cycle of the device. For example, the cross-hatched portions of the line of the bar graph relating to cam 66 indicates the position in the cycle and the duration of the engagement of cam 66 with the switch leaf 69 causing closing the circuit to the igniter, whereas in the line relating to the cam 65, the cross-hatched portion shows the position in the cycle and the duration of the engagement of cam 65 with the sprocket member 78, i.e., with either teeth 79 or surface 81.

As shown in Figure 2, at the start of the cycle, cam lug 65 is not engaging either the surface $1 or any of the eeth 79 on sprocket or ratchet member 78, and cam 66 is not in engagement with switch leaf 69 of switch 61. Thus, at the beginning of the cycle, the motor control switch 63 is opened by the bias of spring 76 acting through pin 77 which engages switch leaf 33. The circuit to the cam motor or the prime mover 46, is made through the normally closed motor control switch 62 which, upon the making of timing switch 122', starts said motor and the shaft 47 revolving as aforestated to thereby revolve

cams

65, 66, 5'6 and 49. Making of the time switch 122, of course, also effects energization of the transformer 45 and hence of winding 32 of operator means 27. p I I As shown in Figure 7, cam lug 49 of the lower camassembly 48 is in engagement with arm 53 of bell-crank lever 51 at the start of the cycle and thus the rotation of shaft 47, in a counterclockwise direction, causes arm 55 and extension 56 of said bell-crank to engage the metal surface 26:: of valve disc 26 and move the latter to the right as viewed in Figures 1 and 7, thereby resetting armature 33 of operator 27 to the pole faces of magnet 31 against the bias of spring 28. This sequence requires 55 degrees of rotation of shaft 47. Since Winding 32 of operator 27 became energized immediately upon the making of the timing switch 122 in the main line conductor 12%, the armature 33 is retained in attracted relation against the pole faces of magnet 31 and the valve disc 26 is held open thereby, allowing the fluid fuel to pass from the inlet chamber 17 into the intermediate chamber 18. From the relative positions of

lugs

49 and 56 shown on the bar graph of Figure 6, it is seen that lug 49 leaves lever arm 53 five degrees of rotation prior to ;lug 50 engaging arm 57 so that prior to opening of valve disc 44 by engagement of the lug 5'6 with arm 57, the arm 53 is released by the lug 49 and the valve disc 26 is thereafter free to seat on release of the armature 33. Since the valve discs 26 and 44 are not simultaneously held open by the lower cam and reset assembly, if there is failure of the alternating current power while the valve disc 26 is being held open by the arm 56, the seated valve disc 44 prevents any 10 fuel flow, whereas if there is alternating current failure after the arm 53 is released by the lug 49, the disc 26 will reseat to prevent all fuel flow, even though the disc 44 may be held open by the arm 59 at the time. Thus, at any time that there is failure of the alternating current power, fuel flow is prevented either by the valve disc 26 or by the valve disc 44, so that the device is fail-safe in this respect.

Upon a further rotation of shaft 47 the aforementioned five degrees (sixty degrees from the original position), upper cam lug 50 of the lower cam assembly 48 engages bell-crank lever arm 57, thereby causing extension 60 of bell-crank lever arm 59 to engage valve disc 44 and move thehousing 35 and the magnet 37a to the left therewith as viewed in Figure 1 a distance suflicient to cause engagement of the pole faces of said magnet with the armature 39. Upon the cracking of valve disc 44 with respect to valve seat 21 (and assuming successful resetting of operator means 527), fluid fuel flows from the intermediate chamber 18 into outlet chamber 19 and thence out auxiliary gas passage 1 6a and conduit 9 to the pilot burner 8. However, fuel may not flow to the main burner 6 because valve disc 41 is held in engagement with seat 22 by the force exerted thereon by rlever arm 59 through the opened valve disc 44 and the latching or holding means 34a.

As shown by the graph (Figure 6), the duration of the engagement of cam lug 50 with lever arm 57 is 284. This allows suflicient time for the fluid fuel to go from outlet chamber 19 to the pilot burner 8 and for ignition thereof by the glow coil 10. It also provides sufficient time following pilot burner ignition for heating of the thermoelectric generator 12-8 by the pilot burner flame and energization of winding 38 of magnet 37a permitting the latter to retain the armature 39 in attracted position therewith against the bias of spring 42, so that the valve disc 41 can be thereafter moved away from seat 22 under the bias of the

flat springs

36 and 37 upon cam 50 moving out of engagement with valve disc 44, all as will hereafter appear.

Five degrees after engagement of cam 5t? with lever arm 57 and sixty-five degrees after the start of rotation of shaft 47, upper cam 66 of upper cam assembly 64 engages resilient switch leaf 69 to close switch 61 and energize the igniter 10 for ignition of the fuel now emanating from the pilot burner 8 (which fuel, as aforementioned, flows to said burner upon the cracking of valve 44). The igniter 10 remains energized for ninety degrees of rotation of the shaft 47, after which the cam 66 leaves the switch blade 69 and switch 61 opens to deenergize said igniter.

After three hundred and ten degrees rotation of shaft 47 from the start of the cycle, lower cam 65 of upper cam assembly 64 engages surface 81 of ratchet or sprocket member 76 to rotate the latter in a clockwise direction. At this time it is presumed that the pilot valve 8 has become ignited. As cam 65 moves the ratchet disc 78 in a clockwise direction, pawl 101 is forced to the left as viewed in Figure 2 by the first ratchet tooth 3t), i.e., the tooth next to teeth 79. This movement of pawl 101 causes arm 99 to engage depending lug 96 of switch blade 91 (Figure 5) and thereby open switch 62. However, this does not stop the motor 46 which continues to be energized by completion of the circuit thereto through the motor switch 63 which makes, or goes to circuit completing position, upon movement of pin 77 away from switch blade 83 with the aforementioned clockwise rotation of the sprocket member 78. Making of switch 63 occurs, of course, prior to opening of the motor switch 62.

Since we are assuming that the pilot burner 8 has ignited in the normal fashion, the armature 39 has become magnetically latched to the pole faces of the electromagnet 37:; by energization of the winding 38 suificient to overcome the bias of spring 42 and provide a unitary assemblage of valve means 24 and 25 and latching means 3411-. It is to be noted that during the period when cam 65 of the upper cam assembly is moving sprocket member 78 in a clockwise direction, cam lug 50 of the lower cam assembly 48 is leaving lever arm 57, thereby allowing the aforementioned unitary assemblage including valve disc 41 to move to the right as a unit under the bias of

flat springs

37 and 36 to an intermediate open position where valve discs 41 and 44 are spaced away from seats 22 and 21 respectively. As shown in bar graph Figure 6, this occurs sixteen degrees prior to the end of the cycle and thirty-four degrees after engagement of cam 65 with surface 81.

The opening of valve 41 causes clockwise rotation of bell-crank lever 106 as viewed in Figures 2 to 4 and lever arm 110 thereof by engagement with arm 100 of bellcrank 105 rotates the latter in a counterclockwise direction to thereby move pawl 101 to the left to the position thereof shown in Figure 3, just clearing the first ratchet tooth 80. Thus, upon cam 65 rotating out of engagement with surface 81 at the end of the cycle, pin 77, under the bias of spring '76, returns with sprocket 78 to the starting position shown in Figure 2, reopening motor switch 63. Since motor switch 62 is held open by bell-

cranks

106 and 105, and motor switch 63 is held open by pin 77 of ratchet assembly 74, the prime mover motor 46 is deenergized and stops.

Fuel, which started flowing to the main burner for ignition by the pilot burner upon the opening of valve 41, normally continues to fiow to the main burner until reopening of the timing switch 122 causes deenergization of winding 32 of operator 27 and release of the armature 33 allowing the seating of valve disc 26 on seat 20. This shuts ofi fuel flow to both burners, cooling generator 128 and deenergizing holding means 34:; to cause release thereof and seating of valve discs 41 and 44 under the bias of spring 42.

In the event that the pilot burner should become extinguished during the operating period, the thermocouple 123 cools as aforementioned to deenergize and release holding or latching assembly 34a causing closure of both valve discs 41 and 44 under the bias of spring 42. This shuts off the flow of fuel to both the main and pilot burners independent of the valve means 23 which may be open at the time. Also, abnormally high heating by the main burner causes release of the holding means 34a and shut oif of the fuel flow by opening switch 139 in the thermocouple circuit.

If, during the first cycle, the pilot burner should fail to ignite, the valve 41 will not open to permit fuel flow to the main burner 6, since winding 38 in the holding means 34a will not become energized to link the arma' ture 39 to the magnet 37a. Thus, when the cam 65 leaves surface 81 of ratchet member 78, the ratchet will have been advanced one step and will be held in the one step advanced position by pawl 101 engaging the first tooth of teeth 80. The motor switch 63, being closed, continues to supply power to motor 47 to recycle the device, cam 65 then engaging the next succeeding tooth 79. If the second cycle is successful in igniting the pilot burner, valve disc 41 will open holding pawl 101 away from the teeth 80 and allowing the ratchet assembly 74 to reassume the positions shown in Figure 2.

In order to prevent continuous cycling of the device in the event of continued failure of ignition of the pilot burner, for example as a result of the igniter failing to work or of some other defect in the operation which prevents normal ignition of the pilot burner, means is provided for shutting down the device after five unsuccessful cycles. As shown most clearly in Figures 4 and 4a, after four unsuccessful cycles, continued cycling moves edge surface 118 of sprocket member 78 into engagement with pawl 101 of bell-crank 97 upon the fifth cycle. Due to the length and configuration of surface 118, it is operable when cam 65 is forcing the ratchet member 78 in a clockwise direction in the fifth cycle,

'to force the pawl 101 radially outwardly to a position spring snaps the bell-crank including pawl 101 to the left to the stable overcenter position thereof shown in Figures 4 and 4a. This, of course, prevents any further coaction between pawl 101 and teeth 80, so that as soon as the cam lug 65 moves out of engagement with coacting tooth 79, the sprocket member 78 rotates in a counterclockwise direction under the bias of spring 76, and the parts assume the position shown in Figure 4a where motor switches 62 and 63 are both open to stop the motor 46. The device remains shut down until the bell-crank 105 is returned to the position of Figure 2 by manual actuation of the reset means 113 to initiate a new series of cycles. This affords an opportunity for an operator to examine the apparatus for the cause of the defect preventing normal ignition.

Figures 8, 9 and 10 show a device very similar to the device described in Figures 1-7 and the parts indicated by primed reference characters correspond to similar parts in Figures 1 to 7 indicated by the same reference characters unprimed. The structure has been modified in Figures 8 to 10 to the extent that it does not have the means aifording shut down of the device after five unsuccessful ignition-attempting cycles. Except as hereinafter noted, however, the operation of the parts of the device shown in Figures 8 to 10 is the same as that shown in Figures 1-7. As shown in Figure 10, the cam assembly 64' has only a single cam lug 66 which actuates a normally open igniter switch 61, there being no equivalent in this device of the ratchet assembly 74 and motor switch 63. Motor switch 62 is actuated by valve member 41 through a bell-crank assembly 106' which is similar to the bell-crank assembly 106 in the first described embodiment. Thus when valve member 41 is opened following successful completion of an ignition cycle, am is moved in a clockwise direction to actuate the normally closed switch 62' and open the circuit between

conductors

94 and 95' leading to motor switch 62'.

Although two specific embodiments of the invention have been shown and described, it is with full awareness that many modifications thereof are possible. The illustrated forms of the invention have been selected for the purpose of disclosure only and are not intended to limit the forms which the invention may take or to confine the invention to a particular use, all of such other forms, modifications, or changes being contemplated as may come within the scope of the appended claims.

What is claimed as the invention is:

1. A fluid fuel control device comprising a valve body having a main fuel passage therethrough, first, second and third valves serially arranged in said fuel passage and movable to open and closed positions for control of the flow of fluid fuel through said passage, means biasing each of said valves toward closed position, said body being provided with an auxiliary fuel passage intersecting said main fuel passage between said second and third valves, first electroresponsive releasable holding means operable when energized to hold said first valve in open position when moved thereto against the bias of the biasing means therefor, second electroresponsive releasable holding means operable when energized to hold said second and third valves in open position when moved thereto against the bias of the biasing means therefor, first and second electric power source means connected to energize said first and second holding means respectively, and electroresponsive reset means energizable by said first source means for resetting said first and second valves to open position against the bias of the biasing means therefor for holding coaction with said holding means, failure of said first source means effecting deenergization and release of said first holding means and closure of said first valve, and failure of said second source means effecting deenergization and release of said second holding means and closure of said second valve, wherefore failure 13 of either source means effects shut off of all fuel flow through said main and auxiliary passages.

2. A fluid fuel control device comprising a valve body having a main fuel passage therethrough, first, second and third valves serially arranged in said fuel passage and movable to open and closed positions for control of the flow of fluid fuel through said passage; means biasing each of said valves toward closed position, said body being provided with an auxiliary fuel passage intersecting said main fuel passage between said second and third valves, first electroresponsive releasable holding means operable when energized to hold said first valve in open position when moved thereto against the bias of the biasing means therefor, second electroresponsive releasable holding means operable when energized to hold said second and third valves in open position when moved thereto against the bias of the biasing means therefor, first and second electric power source means connected to energize said first and second holding means respectively, electroresponsive prime mover means energizable by said first source means for sequentially resetting said first and second valves to open position against the bias of the biasing means therefor for holding coaction with said holding means, and circuit controlling means in circuit with said prime mover means and said first source means and operatively associated with said third valve to inter- 'rupt energization of said prime mover means in response to opening movement of said third valve.

3. A fluid fuel control device comprising a valve body having a main fuel passage therethrough, first, second and third valves serially arranged in said fuel passage and movable to open and closed positions for control of the flow of fluid fuel through said passage, means biasing each of said valves toward closed position, said body being provided with an auxiliary fuel passage intersecting said main fuel passage between said second and third valves, first electroresponsive releasable holding means operable when energized to hold said first valve in open position when moved thereto against the bias of the biasing means therefor, electroresponsive releasable holding and biasing means operable when energized upon opening movement of said second valve to open said third valve and etain said second and third valves in open position against the bias of the biasing means therefor, first and second electric power source means connected to energize said first and second holding means respectively, and electroresponsive reset means energizable by said first source means and sequentially engageable with said first and second valves to reset said valves to open position against the bias of the biasing means therefor.

4. A fluid fuel control device comprising a valve body having a main fuel passage therethrough, first, second and third valves serially arranged in said fuel passage and movable to open and closed positions for control of the flow of fluid fuel through said passage, means biasing each of said valves toward closed position, said body being provided with an auxiliary fuel passage intersecting said main fuel passage between said second and third valves, first electroresponsive releasable holding means operable when energized to hold said first valve in open position when moved thereto against the bias of the biasing means therefor, second electroresponsive releasable holding means operable when energized to hold said second and third valves in open position when moved thereto against the bias of the biasing means therefor, first and second electric power source means connected to energize said first and second holding means respectively, and electroresponsive cycling reset means energizable by said first source means for resetting said first and second valves to open position against the bias of the biasing means therefor for holding coaction with said holding means, means responsive to holding cooperation of said holding means with said second and third valves for terminating operation of said cycling reset means, and means for terminating operation of said cycling reset means in 1'4 7 the event of failure of said holding means to eli'ectholding cooperation with said second and third valves in response to a predetermined number of cycles ofsaid reset means.

5. A fluid fuel control device comprising a valve body having a main fuel passage thereth'rough, first, second and third valves serially arranged in said fuel passage and movable to open and closed positions for control of the flow of fluid fuel through said assage, means biasing each of said valves toward closed position, said body being provided with an auxiliary fuel passage intersecting said main fuel passage between said second and third valves, first electroresponsive releasable holding means operable when energized to hold said first valve in open position when moved thereto against the bias of the biasing means therefor, second electroresponsive releasable holding means operable when energized to hold said second and third valves in open position when moved thereto against the bias of the biasing means therefor, first and second electric power source means connected to energize said first and second holding means respectively, motor driven rest means energizable by said first source means and having rotary actuating means operable during one complete revolution thereof to sequentially reset said first and second valves to open position against the bias of the biasing means therefor for holding coaction with said holding means, motor control means comprising ratchet means and first and second switches in circuit with said motor means and first source means, said ratchet means having a movable ratchet member biased toward an initial position and advanceable against said bias by rotation of said actuating. means, said ratchet member being released for return toward its initial position responsive to holding cooperation of said holding means with said second and third valves, one of said switches being positioned for actuation by return of said ratchet member to its initial position to shut off said motor means, and the other of said switches being positioned for actuation by advancement of said ratchet member in response to a predetermined number of revolutions of said rotary actuating means to shut off said motor means.

6. Control apparatus comprising, first and second control members each having first and second operating positions, first and second coupling members operatively connected to said first and second control members respectively and each having a coupled position 'with respect to the other coupling member and having an initial position in separated relation with respect thereto, disposition of said coupling members in separated relation positioning the respective control members in their first operating positions, first biasing means acting against one of said coupling members and reacting against the other to bias both of said coupling members toward their initial positions and said control members toward their first operating positions, releasable coupling means for coupling said coupling members when in their coupled positions against the bias of said first biasing means, and leaf spring supporting and positioning means supporting said coupling members, control members and biasing means as a unitary subassembly and operatively coacting with said coupling members, when coupled, to position said coupling members so that neither of said coupling members is in its initial position and so that said control members are thereby disposed in their second operating positions, said first biasing means on release of said coupling means, effecting movement of each of said coupling members towards its initial position for movement of each of said control members from its second toward its first operating position.

7. Control apparatus comprising, first and second control members each having first and second operating positions, housing means, first and second coupling members disposed within said housing means and operatively connected to said first and second control members respectively and each having a coupled position with rcspect to the other coupling member and having an initial position in separated relation with respect thereto, disposition of said coupling members in separated relation positioning the respective control members in their first operating positions, first biasing means to bias both of said coupling members toward their initial positions and said control members toward their first operating positions, releasable coupling means for coupling said coupling memberswhen in their coupled positions against the bias of said first biasing means, and supporting and positioning means comprising leaf spring means supporting said housing and thereby said coupling members, said control members and said biasing means as a unitary subassembly and operatively coacting with said coupling members, when coupled, to position said coupling members so that neither of said coupling members is in its initial position and so that said control members are thereby disposed in their second operating positions, said first biasing means on release of said coupling means, effecting movement of each of said coupling members towards its initial position for movement of each of said control members from its second toward its first operating position.

8. Control apparatus comprising, first and second control members each having first and second operating positions, housing means, first and second coupling members disposed within said housing means and operatively connected to said first and second control members respec tively and each having a coupled position with respect to the other coupling member and having an initial position in separated relation with respect thereto, disposition of said coupling members in separated relation positioning the respective control members in their first operating positions, first biasing means acting against one of said coupling members and reacting against the other to bias. both of said coupling members toward their initial positions and said control members toward their first operating positions, releasable coupling means for coupling said coupling members when in their coupled positions against the bias of said first biasing means, and supporting and positioning means comprising leaf spring means supporting said housing and thereby said coupling members, said control members and said biasing means as a unitary subassembly and operatively coacting with said coupling members, when coupled, to position said coupling members so that neither of said coupling members is in its initial position and so that said control members are thereby disposed in their second operating positions, said first biasing means on release of said coupling means, effecting movement of each of said coupling members towards its initial position for movement of each of said control members from its second toward its first operating position.

References Cited in the file of this patent UNITED STATES PATENTS 2,180,675 Gille Nov. 21, 1939 2,261,458 Bailey et al. Nov. 4, 1941 2,290,048 Hildebrecht July 14, 1942 2,427,178 Aubert Sept. 9, 1947 2,456,147 Ray Dec. 14, 1948 2,584,147 Mayer Feb. 5, 1952 2,642,128 Riehl June 16, 1953 2,711,216 Arden June 21, 1955 2,726,716 Russell Dec. 13, 1955