US2547853A - Reset mechanism for pilot safety valves - Google Patents

Description

R. J. BUTTERFIELD RESET MECHANISM FOR PILOT SAFETY VALVES April 3, 1951 3 Sheets-Sheet 1 Filed May 2l, 1948 .ll-ulmEHHH April 3, 1951 R. J. BUTTERFIELD 2,547,853

RESET MECHANTSM FOR PILOT SAFETY vALvEs Filed May 2l, 1948 3 Sheets-Sheet 2 lApril 3, 1951 R. J. BUTTERFIELD RESET MECHANISM EoR PILOT SAFETY vALvEs s sheets-sheet. s

Filed May 2l, 1948 ril I Iv 74 IW Patented Apr. 3, 1951 UNITED STATES PATENT OFFICE RESET MECHANISM FOR PILOT SAFETY VALVES Robert J. Butterfield, San Gabriel, Calif., assignor, by mesne assignments, to Minneapolis- Honeywell Regulator Company, a corporation of Delaware Application May 21, 1948, Serial No. 28,319

4 Claims. ('Cl. 137-139) safety valves.

An object of the present invention is to provide a reset mechanism for pilot operated safety valves of the character described, providing for what is commonly referred to as safe lighting,r that is the positive prevention of fuel flow to the main burner of the heat appliance until after the pilot burner is ignited and properly put in operation.

Another object of the present invention is to provide a reset mechanism of the character above `in which there has been eliminated all auxiliary valves and locking devices upon which the provision of safe lighting has heretofore depended,vwhereby the device of the present invention is rendered more positive and foolproof in its operation.

A further object of the invention is to provide a reset mechanism of the character above which is adaptable for use with all existing forms of pilot safety valves and more particularly to existing forms of thermostatically operated catches and releases including such types as electromagnetic, bimetal, deecting tube, etc.

The invention possesses other objects and features of advantage, some of which, with Vthe foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and forming part of the specication. It is to be understood, however, that variations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claims.

With reference to said drawings:

Figure 1 is a cross sectional view of a pilot operated safety valve constructed in accordance with the present invention.

Figure 2 is a fragmentary view of the reset mechanism in the shut-olf position of thevalve.

Figure 3 is a fragmentary cross sectional view of the reset mechanism in another position of the parts.

Fig-ure 4 is a fragmentary cross sectional view of the reset mechanism in still another position ofthe parts.

Figure 5 is-a cross sectional View of a modied form-of the safety valve.`

Figure `6 is a fragmentary cross sectional view of the reset mechanism illustrated in Figure 5 but in a different position of its several parts.

The safety valve illustrated in the the accompanying drawings includes a valve body I I, formed with an internal gas passage I2 extending between inlet and outlet openings I3 and I4 adapted for connection to conduits in the fuel line to the main burner of a heat appliance. Provided in the passage I2 is an annular yvalve seat I6 and a valve I'I movable to and from the seat to close or open iiuid flow through the passage. The valve Il is constantly urged to a closed position by a helical spring I8 but is held in an open position during normal operation by a thermostatic catch means I9 energized by a pilot burner 2| which in an appropriate installation is mounted in proximity to the main burner of the appliance and is in constant operation so as to provide periodic ignition of the main burner as fuel is supplied thereto. Upon extinction of the pilot flame, the thermostatic catch means I9 is operated to release the valve Il for movement to its closed position under the urge of spring I8 so as to thereafter prevent the flow of fuel to the main burner of the appliance. After closing of the valve Il as above described, means is provided for opening the valve and resetting the thermostatic catch means I9 after the pilot burner is again ignited and put in proper operation. During this resetting operation it is important that the valve I 1 remains closed until after it is certain that the pilot is in proper operation. This provision in pilot safety valves is commonly referred to as safe lighting and is particularly important Uwhere gas is used as the fuel so as to prevent the iiow of gas to the main burner until after the pilot burner has been ignited and put into operation.

With reference to the drawings the reset mechanism includes a member 2| which is mounted in the body II for reciprocation and having one end 22 extending from the body and tted with a button 23 for manual engagement and displacement, in conjunction vwith means 25 providing a detachable connection between the valve I'I and the member 2| for displacing the valve to open position and the operation of which means is controlled by the thermostatic catch means I 9 so as to make and break such connection in the caught and uncaught the means I9. Preferably the member 2I is mounted axially through the valve seat I E and extends centrally through and provides a sliding support for the valve I'I so as to properly guide the valve in its movement to and from the seat I6` positions respectively of K A helical spring 24 is positioned around the member 2| and compressed between a closure part 26 for the body and a washer 21 mounted on the member 2| so as to constantly urge the member 2| to a position inwardly oi the body, that is with the button 23 on the outer end of the member drawn up against the closure part 28. Oi importance in this construction is the fact that spring 24 is somewhat stronger than spring I8, so that in the attached position of member 2| and the valve II, spring 24 will over come the resilience of spring I8 and provide for the opening of Valve I'I Means for controlling the operation o the detachable connection 25 here includes a longitudinal extension 28 slidably carried for relative longitudinal movement by the inner end 28 of member 2|. As will be seen from Figure 1 the inner end 29 of member 2| is provided with an axial bore 3| which slidably receives spaced enlarged end portions 32v and 33 on the member 28. A ring key 34 xed in the bore 3| between the enlarged end portions 32y and 33 limits the amount of relative longitudinal movement between members 2|. and 28. A. helical spring 38 compressed between the end 28 of the member 2 I and a washer 3l on the member 28 normally urges Vthe member 28 to a distended position relative to member 2|, that is with the enlarged part 3,2 on member 28 positioned in abutment with the key 34 as illustrated in Figures 2 and 3 of the drawing.

The detachable connection 25 here consistsy of a plurality of balls mounted in peripheral openings 38 in the member 2| extending from the bore 3| to the exterior periphery of the member. Surrounding the balls 25, the valve I'I is provided with an enlarged chamber 38 deinedv at its base by an inclined shoulder 4I'. In the position of the parts illustrated in Figure 1 of the drawing, the balls 25 are forced outwardly in the openings 38 by the enlargedv part 32 on member 28 so as to hold the balls betweenl the walls of the openings 38 and the inclined shoulder 4| on theV valve to thereby establish a connection between member 2| and the valve. The end surface 42 of part 32 is reduced to a conical point so that on relative outward movement' of part 28` with respect to member 2| as illustrated in Figures 2 and 3 of the drawing, the pointed end 42 of. member 28 is positioned opposite to the balls 25 and the balls are thereby permitted to move inwardly through openings 38. and into the bore-3| so as to permit the valve I'I to slide freely longitudinally on the member 2 I. It will be noted that thislatter inward movement of the balls 25 is caused in part by the tapered shape. of the shoulder 4I which is inclined to the longitudinal axisof the member.

The thermostatic catch means I9 may be of any one of several types available. The type depictedin Figure 1 of the drawing includes aI bimetal element 43 mounted in proximity tothe pilot burner 2| so as to be heated thereby, and being so constructed and mounted that when heated, the outer end 44 will move laterally across and. engage the end face 45 of the member 28. This general form of thermostatic latch means is more fully illustrated and described in Jenkins Patent No. 2,322,520, issued June 22, 1943. The element 43 is supported at the outer end of a tube 41, threaded into a boss 48 provided on therear side of the body and extends away from the body in axially alignment with member 2| and its associated part above described, and in surrounding relation to the extension member 28. Preferably the element 43 is enclosed in a capsule 49 so as to shield the element from direct contact with the pilot ame. As here illustrated the base 5| of the element is anchored, leaving the opposite free end 44 capable of swinging to and from the axis of member 28 in response to the heat received from the pilot burner. The arrangement of the bimetal element is such that upon extinguishing of the pilot burner 2| and cooling of the element, end 44 of the element will swing away from the axis member 28 as illustrated in Figures 2 and 3 of the drawing so as to prevent relative longitudinal movement of member 28, that is to its distended position as above described. Conversely upon ignition of the pilot burner and heating of element 43, the free end of 44 thereof will swing towards the axis of member 28 so that when the member is moved with the reset member 2| to the positions illustrated in Figures 1 and 4 of the drawing,l the" end 44 of the element will swing across the end face of 48 of member 28 and prevent its return outward movement.

As will be understood by those skilled in the art, there are a variety of thermostatic latchmeans which may be used in connection withl the present invention, such as the deflecting tube type illustrated in Drow application, Serial Number 783,234, led October 31, 1947, now Patent No. 2,530,942, dated November 21, 1950, for Temperature Responsive Safety Valve, or a thermomagnetic type of latch such as illustrated inv Figures 5 and 6 of the drawing.

summarizing the foregoing description of th'e several parts, the operation of the device as follows. The several' parts are shown in their normal operating position in Figure 1 of the' drawing wherein the valve I1 is held in operi position permitting fluid flow to the main burner. Balls 25 are held outwardly by part 32 so as to lock the valve I1' to the reset member 2| and the`v valve and member 2| are held inwardly with respect to the body by means ofspring 24'. At the same time the outer end 48 of member 28 is stopped by the hooked end 44 of the bimetal element 43 so that member 28 is held in relatively telescopedA position with respect to member 2| thus compressing spring 36. Upon extinguishing of the pilot burnerY 2|, bimetal element 43A cools and retracts from the outer end of element 28 as illustrated in Figure 2 of the drawing, thereby causing member 28 to spring outwardlyy with respect to member 2'Iv under the action of spring 35. This relative movement of member 28" withdraws the enlargedfend 32 of member 28 fromn the base of the openings 38 thereby permitting' the balls 25 to move inwardly on to the pointed forward. end of 42 and thus release the valve I'I for movement longitudinally on member 2| to` a closed position of the valve' against seat I6 under the action of the valve closingv spring I8. Valve I'I' thusv moved toits closed position prevents further passage of fuel to the main burner until after resetting of the device has been accomplished. When the pilot burner 2| has been reignited and put into proper operation, the first step in the resetting procedure takes place as illustrated in Figure 3 of the drawing. The opera-A tor engages the knob 23' at the front end of member 2`I, and4 pulls. member'v 2|' outwardly with respect to the body and against the resistance of Y spring 24. The inter-connection between members 2| and 28 afforded by the ring key 34 causesl member` 28 to move with' member 2| tol again position the outer end 46 of member 28 opposite to the inturned end 44 of the thermostatic element 43. In this movement of parts 2| and 28, it will be noted that valve remains in aV seated position, although it will beV noted that the balls 25 have been drawn forwardly into the valve chamber 39. If the pilot burner has been put into proper operation and suiiicient time permitted to elapse so as to heatv the thermostatic element 43, the end of 44 of the element 43 will have been moved laterally across the end face 46 of member 28 so as to prevent the return outward movement of member 28. On the other hand if the pilot burner has not been put into proper operation, the bimetal element will not have moved to stop the return movement of member 28 and a release of member 2| from its outwardly drawn position as illustrated in Figure 3 will merely return the parts to an inoperative position as illustrated in Figure 2 without effecting an .'opening of valve I. On the other hand if pilot burner operation has been properly instituted and the bimetal element 43 heated and displaced as above explained, then the end 44 of the element will prevent the ,return movement of' member 28 as illustrated in Figure 4 of the drawing. As the knob end 23 of member 2| is permitted to return from its outwardly drawn position as illustrated in Figure 3, the relative movement between members 2| and 28 will force the balls 25 over the pointed end 42 and into engagement with the base 4| of the valve chamber 39. This position of the parts is illustrated in Figure 4 of the drawing. Further and full return of member 2| will then displace the valve away from its seat |6 to a position of the parts as illustrated in Figure 1. In this last named return movement of member 2| it will be noted that both the valve spring I8 as well as the spring 36'separating members 2| and 28, are compressed by reason of the greater compressive force of spring 24.. In accordance with the foregoing it will be clear that it is impossible in the operation of the reset means 2| to open valve and thereby permit passage of fuel to the main burner until after the pilot burner 2| has been properly ignited and put in operation.

A modified form ofthe invention has been illustrated in Figures 5 and 6 of the drawing wherein a thermo-couple electro-magnet type of latch is shown instead of the bimetal type in the above described embodiment. As here shown a horseshoe magnet 52 is mounted centrally with respect to the outer end 53 of member 28', thelatter being mounted for reciprocal movement in a slide bearing 54 provided through the base cf the magnet 52. The magnet is energized by a fieldwinding 55 provided on the legs of the magnet and which are connected vby conductor 5l to a thermo-couple 58 mounted in proximity to the pilot burner 2 Thus during normal and proper operation of the pilot burner, thermo-couple 58 is heated and thereby generates an electrical potential in Lturn energizing lthe held coil 53 and the magnet core 52. An armature or keeper 59 is secured to the outer end 53 of member 28' and which upon engagement with the pole faces of magnet 52, as illustrated in Figure 5, will be firmly held fast thereon when the magnet is'. energized as described.

Upon extinguishing of the pilot name, in the form of the invention illustrated in Figures 5 and 6, the thermo-couple 28 will cool and thereby collapse the magnetic eld at magnet 52 and release the armature 59 for relative outward movetime mentor, par-t 28.` .This relative. outward move-` the first embodiment, permits aninward movement of balls 25 across the pointed end 42' so as to thereby release the valve I1 for closing under the operation of its closing spring |8, 1t being noted that the initial outward movement of element 28 is caused as above described by the spring 35 constantly urging the separation of members 2| and 28. The released, shut-off position of the several parts is illustrated in Figure 6. The resetting operation of this modified form of the invention is identical with that described in connection with the first embodiment illustrated in Figures l to 4 of theV drawing. To better adapt the device to thermo-magnetic operation, it may be noted that a slight change has been made in the specific arrangement for effecting the sliding and interconnecting attachment of members 2| and 28', but such change is merely structural without changing the relative functioning of the parts.

claim:

1. A pilot operated safety valve comprising, a valve body having a fuel passage and an annular valve set therein, a member mounted for reciprocation in said body and extending through said seat coaxially thereof and having an end extending from said body for manual engagement and displacement outwardly of said body, a spring normally urging said member to an opposite reciprocal position inwardly of said body, a valve slidably carried on said member for movement v to and from said seat, a second spring normally urging said valveto said seat, a second member l slidably carried by said first member and extending longitudinally therefrom the direction Y opposite to said first end, a third spring mounted between said first and second members and normally urging said members to a relatively distended position, a thermostatic element mounted Vadjacent to the axis of movement of said second member and functioning when heated to intercept and hold said second member upon movement of the latter upon manual displacement of said rst member whereby upon return movement of said first member under the action of said first spring a relative movement between said first and second members will be eifected against the resistance of said third spring and detent means carried by said rst'member and extendable therefrom for engagement With said valve and. being connected to said second member and operated thereby upon the aforesaid relative movement between said first and second members whereby upon said return movement of said first member said detent means will engage and displace said valve to open position against theresistance of said second spring.

2. A pilot operated safety valve comprising,- a valve body having a fuel passage and an annular valve set therein. a member mounted for reciprocation in said body and extending through said seat coaxially thereof and having an end extending from said body for manual engagement and' displacement outwardly of said body, a spring normally urging said member to an opposite site to said rst end, a third spring mounted'.

between said rst and second members and norans-mess mally urging said members to a relatively distended position, an armature mounted on said second member, an electromagnet positioned for engagement with said armature upon manual displacement of said first and second members as aforesaid and arranged when energized to hold said second member thereby to cause a relative movement between said rst and second members against the action of said third spring upon return movement of said iirst member by said first spring, and detent means carried by said rst member and extendable therefrom for engagement with said valve and being connected with said second member and operated thereby upon the aforesaid relative movement of said first and second members whereby upon said return movement of said iirst member said detent means will engage and displace said valve to open position against the resistance of said second spring.

3. A safety valve comprising, a valve body vhaving a fuel passage and an annular valve seat therein, a member mounted for reciprocation in said body and extending through said seat coaxially thereof and having an end extending from said body for manual engagement and displacement outwardly of said body, a spring normally urging said member to an opposite reciprocal position inwardly of said body, a valve slidably carried on said member for movement to and from said seat, a second spring normally urging said valve to said seat, a second member slidably carried by said rst member and extending longitudinally therefrom in the direction opposite to said rst end, a third spring mounted between said rst and second members and normally urging said members to a relatively distended position, thermostatically operated catch means functioning when energized to engage and hold said second member upon movement of the latter upon manual displacement of said first member whereby upon return movement of said 4rst member under the action of said first spring a `relative movement by the said iirst and vsecond members will be eifected against the resistance of said third spring, and detent means carried by said rst member and extendable therefrom for engagement with said valve and being positioned for actuation 'by said second Ymember upon the aforesaid relative movement by the said first and second members whereby uponsaid return movement of said rst member said detent means will .engage and displace said valve to open position against the resistance of said second spring.

4. A safety valve comprising, a valve body having afuel passage and an annular valve seat therein, an elongated member composed of telea scopically mounted inner and outer sections supported for reciprocation in said body and extending through said seat coaxially thereof, the outer of said sections having an end extending from said body for manual engagement and displacement ,outwardly of said body, a spring normally urging said outer section to an opposite reciprocal position inwardly of said body, a valve slidably carried on said outer section for movement to and from said seat, a second spring normally urging said valve to said seat, said inner section being slidably carried by said outer` section and extended longitudinally therefrom yin a direction opposite to said first end, a third spring normally urging a relative distension of said sections, means limiting said distension, thermostatically operated catch means functioning when energized to hold said inner section upon movement of the latter by manual displacement of said outer section whereby upon return movement of said outer section under the ,action of said rst spring a relative movement by the said sections will be effected against the resistance of said third spring, said outer section having a chamber and registering opening to the outer periphery thereof, a AVball mounted Iin said chamber, the inner end of said inner section entering said chamber `and being pointed for engagement with and displacement of said ball whereby upon relative contraction of said `sections said ball will be displaced outwardly of said chamber through said opening and into engagement with said valve and upon relative distension of said sections said ball will be released for movement into ,said chamber to disengage said valve.

ROBERT J. BUTTERFIELD.

REFERENCES CITED The following references are of record in the file yof this patent:

UNITED STATES PATENTS Number 'Name rDate 1,480,873 Wagner Jan. 15, 1924 '2,427,935 Van Denberg Sept. 23, 1947

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