US2831491A - Safety valve - Google Patents

Description

April 1958 J. M. CUNNIEN ET AL 2,831,491

SAFETY VALVE Filed May 20, 1953 INVENTOR. JAMES M. CUNNIEN BY MELVIN G. SOGGE ,ga u

- ATTORNEY SAFETY VALVE Application May 20, 1953, Serial No. 356,202 Claims. (Cl. 137-66) This invention relates to safety devices in general and, more specifically, to a safety valve of the manually reset type wherein main and pilot burner valves are held in their open positions by an electromagnet energized by a thermocouple which, in turn, is heated by a flame at a pilot burner.

Valves of the above mentioned type are generally well known in the prior art. However, the heating controls industry is constantly striving to make improved, less costly and more compact valves of this type to enable them to be used in heating apparatus which has to be positioned in places of very limited extent.

It is therefore a primary object of this invention to provide a very compact, inexpensive and simple safety valve that is durable and reliable in operation.

Another object of the invention is to provide a safety valve that may be readily assembled and disassembled.

Another object of the invention is to provide a one hundred percent shut-off valve having axially aligned inlets and outlets for the main gas and selectively useable outlets, one at each side of the valve body, for connection with a pilot burner.

Still another object of the invention is to provide, in a safety valve, a simple actuating mechanism for the main and pilot valves of a scissors-like construction with a simple manually operable actuator for said mechanism.

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

Figure l is a vertical cross-sectional view of the safety valve along the longitudinal axis thereof; and

Figure 2 is a cross-sectional view of the valve taken along the line 2-2 of Figure l.

The valve body or housing consists of a lower casting 11 having aligned and threaded inlet and outlet openings 12 and 13, respectively, with a dividing or partition wall 14 therebetween. The lower casting 11 is open at the top thereof and has a peripheral edge 15 that lies in a flat plane inclined at an angle to the longitudinal axis of the inlet and outlet of the valve body. The partition wall 14 has an opening 16 therein which is substantially coaxial with the inlet and outlet and has a valve seat 17 machined in the inlet side of the partition around the opening 16. A thickened wall portion 11a above the outlet 13 has a bore 18 therein extending into the wall portion from the inner surface thereof and has a valve seat 19 machined in the inner surface around the bore 18. Small diameter bores 20 and 21 extend from the bore 18 laterally through the thickened wall portion 11a to opposite sides of the valve body and terminate in threaded enlarged bores 22 and 23, respectively. The bores 22 and 23 are illustrated as being sealed by plugs 24 and 25, respectively, which may be selectively re moved for the reception of a conduit (not shown) leading to a pilot burner P, schematically shown in Figure 1,

tas atent ICE.

for heating a thermocouple A-B, for a purpose to be hereinafter described.

The valve body or housing also includes an upper casting 26 that is open at its lower edge and has an aperture 27 in one side wall thereof in axial alignment with the bore 18 in the opposite end wall of the lower casting. The lower peripheral edge of the upper casting lies in a flat plane that is inclined to the axis of the inlet 12 and outlet 13 at the same angle as the upper edge of the casting 11. The upper casting 26 is secured to the lower casting 11 with a sealing gasket 28 therebetween by means of bolts (not shown) extending freely through bores 29 in the upper casting and threaded into aligned bores (not shown) in the lower casting. The two castings, when so bolted together, form a generally rectangular shaped hollow housing that encloses the operating mechanism for the valve, now to be described.

A valve 30, having a soft facing 31, made of'rubber or other suitable material, is supported at the lower end of a bell crank lever 32 in a conventional manner, with e an annular rib on the soft facing 31 in engagement with the valve seat 17. The upper portion of the lever 32 is of channel-shape, which has a full width aperture 33 formed in the upper portion of the channel-shaped portion. The aperture 33 joins with a centrally disposed aperture 34 at the lower end of the aperture 33, with the width of aperture 34 being less than half the width of the channel portion. The upper end of the aperture 33 is spaced a short distance from the upper end of the channel portion and forms a cross bar arm 35 as the other arm of the bell crank lever 32. The lever 32 is pivoted on a pivot 36 supported in grooves 37 in the upper casting 26, with the pivot being held in said grooves 37 by means of projection (not shown) on the lower casting 11.

Another bell crank lever 38 has an intermediate channel-shaped portion 38a thereon and is pivoted at its upper end to the casting 26 on the same pivot 36 as is the lever 32. One arm of the bell crank lever 38 extends downwardly and transversely from the channel-shaped portion 33a through the aperture 34 in lever 32 to a point spaced from but substantially in axial alignment with the center of the valve 30. A coil tension spring 39 has one end thereof hooked through an aperture l0 in the lower end of the lever 38 and the other end thereof hooked through an opening 41 in the lower end of the lever 32. This spring 39 normally holds the lower end of the slot 34 in the lever 32 against the lever 38 but will stretch to permit separation of the lever 38 from the lever 32 for a purpose to be hereinafter described. The other end or arm of the bell crank lever 38 extends laterally from the pivot 36, on the opposite side of the pivot 36 from the arm 35 on lever 32, and has an off set portion 42 which is substantially in alignment with the arm 35 and pivot 36.

A conventional electromagnetic unit, that is adapted to be energized by the pilot burner heated thermocouple, is generally designated by the reference numeral 43. It comprises a core 44, a coil 45, an armature 46 and a housing 47. The magnetic unit 43 is secured within the valve body, against the side wall of the upper casting 26, by means of a threaded electrical connector tube 48 which extends through the aperture 27 in the casting 26. A nut 49 is threaded on the tube 48 into clamping engagement with the casting 26 to rigidly hold unit 43 in its assembled position. In Figure 1 of the drawing, the electromagnetic unit 43 is shown schematically as being connected to the elements A and B of a thermocouple by means of lead lines C and D, respectively. The stem 50 of the armature 46 extends slideably through one end of the housing 47 and supports intermediate its ends, between two split rings 51 in annular grooves (not shown) in the stem 50, a cup-shaped spring abutment member 52. A coil compression spring 53 extends between the member 52 and the housing 47 and normally holds the armature 46 spaced from the ends of the core 34 of the electromagnet. The armature stem and one of the split rings 51 also extends through an elongated slot 54 in the base portion of the channel-shaped portion 38a of lever 38 and carries an abutment member 55 thereon in loose engagement with the opposite side of the base portion of lever 33 from the abutment 52. It will be noted that the base portion is arcuate in shape so that as the lever 36 is pivoted about the pivot 36, it will have line contact with the abutment 52 on opposite sides of the armature stem'50 and, due to the fact that the abutmeat 55 has loose engagement with the base portion, there will be a slight sliding or wiping action of the lever 38 across the surface of the abutment 52.

Carried by the opposite end of the armature stem from the armature 46, is a pilot valve 56. This pilot valve has a large threaded bore 57 that threadingly receives an externally threaded sleeve 58 slideably mounted on the armature stem 50. The valve 56 is also provided with a smaller axial and threaded bore 59 that threadingly receives a bolt 60. The bolt 60 has an octagonal head portion that serves as a guide for the armature stem by a sliding engagement in bore 13. The head of the bolt 60 also bears against a washer 61 to clamp a soft washer 62 to the valve 56. A spring 63, positioned between the abutment 55 and the sleeve portion 58 of the valve 56, normally holds the washer 62 of the valve 56 in sealing engagement with the valve seat 19.

There is a lost motion connection between the armature stem 54? and the pilot valve 56 which consists of a stepped bore 64 in the sleeve 58 and a split ring 65 positioned in an annular groove (not shown) near the end of the armature stem 59, positioned within the pilot valve 56. It will be observed that in the closed position of the main and pilot valves, as illustrated in Figure l of the drawing, the split ring 65 is spaced at short distance from the bottom of the bore 64 in the sleeve 53. This means that the washer 62 is resiliently held against the seat 19 by the force of the coil spring 63 reacting against the abutment 55 on the armature stem. This also assures that both the valve 56 and the valve 30 will always be able to reach their respective valve seats regardless of slight variations in manufacturing tolerances and uneven wearing of the valve washers.

As was indicated above, the electromagnet is one that is to be energized by a thermocouple and, consequently, would not have sufiicient force to attract the armature and open the main and pilot valve. Therefore, manually operable means is provided to reset the armature and to open the main and pilot valves. This means consists of a plunger 66 extending through a step bore 67 and having secured to the upper end thereof a manually engageable knob 68 and having loosely supported at the lower end thereof, within the valve body, a floating lever 69. The knob 68 is resiliently biased outwardly by means of a coil spring 70 extending between the inner surface of the knob and a spring retaining abutment washer 71. The knob 68 is vertically slideable in a cup-shaped raised portion 72 formed on the outer surface of the upper casting 26 and the spring retainer washer 71 resiliently clamps a packing washer 73 around the plunger 66 and against the bottom of the enlarged diameter portion 67a of the step bore 67. The lever 69 is loosely supported on the plunger 66 between two spaced split washers 7d and 75 positioned in annular grooves formed in the plunger 66. The upper split washer 75 resiliently clamps a sealing washer 76 around the stem of plunger 66 and the inner surface of the casting 26, under the bias of spring 7d. The lever 69 has a downwardly and laterally offset arm 77 positioned over the arm 35 of lever 32 and another downwardly and laterally offset arm 78 positioned over the arm 42 of lever 38. A pair of spaced guide arms 75 extend downwardly from the center portion of the lever 69 along one side of the pivot 36 so that any tendency for the lever 69 to rotate about the plunger 66 will be stopped by one of said arms 79 engaging the pivot 36. This properly retains the arms 77 and 78 over the arms 35 and 42, respectively, so that inward movement of the plunger 66 will cause said arms to en gage for a purpose to be presently described.

Operation with the above described safety valve installed in a heating system, the inlet 12 being connected to a source of gas supply, the outlet 13 being connected to a main burner, either the outlet 22 or 23 connected to the pilot burner and the electromagnetic unit 43 connected to a thermocouple, the heating system may be put into operation by manually depressing the knob 68. The downward movement of the knob 68 will cause the lever 69 to move downwardly into engagement with the lever 38 and the lever 32, with the arm 77 is engagement with the arm 35 and the arm 78 in engagement with the arm 42. Further downward movement of the knob 68 will cause the lever 69 to pivot about the arm 35 and rock the lever 38 clockwise about the pivot 36. This clockwise movement of the lever 38 will cause the armature stem 59 to be moved toward the left to position the arma ture 46 against the ends of the core 44 and cause the split ring to engage the pilot valve and lift it olf of the valve seat 19. Gas will then flow from the inlet 12 along side of the head of bolt 60 and transversely to either passage 20 or 21 to the pilot burner. It will be noted that the clockwise rotation of the lever 38, while the lever 69 is holding the valve 3i) closed, causes the spring 39 to be stretched and the lever 38 to separate from the lever 32. By igniting the gas issuing from the pilot burner and retaining the knob 38 depressed a sufficient length of time to allow the thermocouple to be heated sufiiciently to energmze the electromagnet and then releasing the knob 68 to be returned to its outermost position under the bias of spring 70, thus lifting the lever 69 away from the lever 32, the spring 39 will be enabled to bias the valve 36 to its open position with the lower end of the slot 34 abutting the lever 38. This permits gas to flow to the main burner where it will be ignited by the pilot burner, which flow will be continued so long as there is a flame present at the pilot burner and there is a heat demand. Should the pilot burner flame become extinguished for any reason, the electromagnet will become deenergized to release the armature and to permit the spring 53 to bias the levers 38 and 32 counterclockwise to first close the pilot valve 56 and, thereafter, the main valve 30 by the armature stem 50 sliding through the sleeve member 58 of the pilot valve 56.

While the preferred embodiment of the invention has been illustrated in the drawing and described in the specification above, it is deemed to be apparent that modifications may be made therein without departing from the spirit of the invention. Therefore, it is to be understood that the scope of the invention is to be determined solely by the appended claims.

We claim as our invention:

1. A control device comprising first and second bellcrank levers pivoted intermediate their ends and movable between on and off positions, control means positioned to be operated by one end of the first lever, safety mechanism engaging said second lever for releasably holding one end of the second lever in its on position, resilient means for moving said one end of the second and first levers toward each other to move the first lever to and to hold it in a safety position when said second lever is in its on position, and setting means arranged to act upon the first and second levers to hold said first lever in its off position while moving the second lever to its on position.

2. A control device as defined in claim 1 wherein said setting means acts on the other ends of the first and second levers.

3. A safety valve comprising a valve body having an inlet and an outlet, a partition between said inlet and outlet and having an opening therethrough, first lever pivoted intermediate its ends on a pivot in said valve body, a valve mounted to be actuated by one end of said first lever and positioned to cover and uncover said opening, a second lever pivoted intermediate its ends on said pivot and having one end thereof on one side of said first lever and the other end thereof on the other side of said first lever, means extending between said levers for biasing the said one end of said first lever toward said one end of said second lever, condition responsive means having a first portion normally biasing said second lever against said first lever and holding said valve against said partition and over said opening and a second portion responsive to a condition for holding but not moving said first portion to a position which enables said valve to open, and manually operable means for engaging the other ends of said first and second levers to hold said valve closed while moving said first portion to valve open position.

4. A control device comprising first and second crossed levers pivoted intermediate their ends ona common pivot, control means positioned to be operated by one end of the first lever, safety mechanism for releasably holding one end of the second lever in a control on position, means for moving a portion of the rst lever into engagement with a portion of said second lever to move the first lever to and to hold it in a safety position when said second lever is in operating position, and setting means arranged to act upon the first and second levers to hold said first lever in its safety position while moving the second lever to its operating position.

5. A safety valve comprising a valve body having an inlet and an outlet, a partition between said inlet and outlet and having an opening therethrough, a first lever pivoted intermediate its ends in said valve body, a valve mounted to be actuated by one end of said first lever to cover and uncover said opening, a second lever pivoted intermediate its ends in said valve body, tension means between said levers for biasing said one end of said first lever toward one end of said second lever, condition responsive means having a first portion normally biasing said second lever against said first lever and holding said valve against said partition and over said opening and a second portion responsive to a condition for holding but not capable of moving said first portion to a posi tion which permits said valve to open, and manually operable means for engaging the other ends of said first and second levers to hold said valve closed while moving said first portion to valve open position.

6. In a safety device, the combination comprising first and second crossed levers pivoted on a common pivot, a control member positioned to be actuated by a portion of the first of said levers, means biasing said portion of said first lever toward a portion of the second lever, means biasing said second lever against said first lever to normally hold said control member in an o position, condition responsive means having a fixed portion responsive to a condition and a movable portion in engagement with said second lever and normally spaced from said fixed portion, said fixed portion being capable of holding said movable portion but incapable of moving it into engagement therewith when said condition exists to hold said control in an on position, and means ineluding a movable member that when moved reacts against said first lever to hold said control in said off position while it bears against said second lever to cause said second lever to move away from said first lever and to move said movable portion into engagement with said fixed portion.

7. In a safety device, the combination comprising first and second levers pivoted intermediate their ends on a common pivot, a control member positioned to be operated by a portion of said first lever, means for biasing said first lever toward the second lever, means biasing said second lever against said firs-t lever to normally hold said control member in one position, condition responsive means having a fixed portion responsive to a condition and a movable portion in engagement with said second lever and normally spaced from said fixed portion, said fixed portion being capable of holding said movable portion but incapable of moving it into engagement therewith when said condition exists to hold said control in a second position, and means including a movable member that when moved reacts against said first lever to hold said control in said one position while it bears against a said second lever to cause said second lever to move away from said first lever and to move said movable portion into engagement with said fixed portion.

8. A safety device as defined in claim 7 in combination with a second control operably connected to said second lever and movable with said lever from one normal position to another position wherein said movable portion is in engagement with said fixed portion.

9. A control device comprising firs-t and second pivoted and crossed levers movable between on and off positions, control means positioned to be operated by one end of the first lever, safety mechanism for releasably holding one end of the second lever in its on position, means for moving a portion of the second lever into engagement with a portion of said first lever to move the first lever to and to hold it in its 0 position, and manually opera'ble setting means arranged to act upon the first and second levers to hold said first lever in its off position and to move the second lever to its on position, said setting means being biased to return to its normal position upon release thereof to perm-it said first lever to move to its on position.

10, The combination comprising a housing, a first lever pivotally mounted in said housing, a second lever pivotally mounted in said housing and having one end thereof positioned on one side of said first lever and the other end thereof positioned on the other side of said first lever, a control member positioned to be operated by said first lever, means for biasing said first lever toward said second lever, means biasing said second lever against said first lever to normally hold said control member in an off position, condition responsive means having a fixed member and a movable member that can be held by but not moved to said fixed member upon the occurrence of a condition, said movable member being operably connected to said second lever and normally spaced from said fixed member, and manually operable means positioned to react against said first lever to hold said control member in its 0 position while bearing against the second lever to move the movable member into engagement with said fixed member upon movement thereof in one direction and if said condition exists to free said first lever and the control member for movement to their on positions upon return movement of said manually operable means.

References Cited in the file of this patent UNITED STATES PATENTS 2,245,834 Sparrow June 17, 1941 2,387,164 McCarty Oct. 16, 1945 2,455,542 Weber Dec. 7, 1948 2,533,982 Weber Dec. 12, 1950 2,719,531 Sogge Oct. 4, 1955

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