US3219774A - Ignition shorting switch - Google Patents

Description

Nov. 23, 1965 c DOBBIN 3,219,774

IGNITION SHORTING- SWITCH Filed July 1, 1965 INVENTOR. I M44453 6. 2052/41 United States Patent 3,219,774 IGNHTEUN SHORTENG SWITCH James (I. Dobbin, Inglewood, Califi, assignor to Honeywell End, a corporation of Delaware Filed July 1, 1963, Ser. No. 231,745 3 Claims. (Cl. ZOO-41.86)

This invention relates to switch means for use on a safety pilot control valve for normally grounding an i gnition circuit for a gas burner during the time that there is no call for ignition and for breaking the circuit to the ground when the safety pilot control is being operated to energize the ignition circuit. More specifically, the invention relates to a switch means which is adapted to be added to a manifold gas valve in such a manner as to enable it to be actuated by a resetting mechanism for a safety pilot portion of the valve during a starting operation of a gas burner controlled by the manifold valve.

One of the objects of the invention is to provide an inexpensive and reliable switch for actuation by a resetting mechanism for a gas valve to control an ignition circuit associated therewith.

Another object of the invention is to provide a switch means for controlling an ignition circuit and is adapted to be readily added to a safety pilot valve already installed in a heating system. a

A still further object of the invention is to provide switch means wherein a movable contact of the switch means provides its own biasing to normally hold the switch in one of its two operating positions.

Further objects of the invention will become apparent upon reading the following detailed description thereof in conjunction with the accompanying drawing wherein:

FIGURE 1 of the drawing illustrates a side elevational View of a manifold valve incorporating the invention;

FIGURE 2 is a drop plan view of the manifold valve with portions thereof broken away;

FIGURE 3 is a cross-sectional view of a safety pilot portion of the manifold valve taken along line 33 of FIG- URE 2;

FIGURE 4 is a cross-sectional view of the switch means taken along line 44 of FIGURE 2 of the drawing; and,

FIGURE 5 is a wiring diagram of the ignition circuit showing the switch means in the circuit thereof.

The reference numeral 11 generally designates a manifold valve incorporating a main valve body portion 12, a safety pilot valve portion 13, a pressure regulator Valve portion 14 and a thermostatic valve portion 15. As none of these valve portions constitute or form a part of the invention per se and may be conventional valve units, it is to be understood that the invention lies in the switch means per se and in its combination with the safety pilot valve unit 13, which will be described in more detail.

The safety valve portion 13 embodies a manually operable plug valve 16 located in a conical bore 17 and adapted to be rotated by a knob 18. The knob has a splined connection with a hollow stem 16a of the plug valve to enable it to move axially with respect to the plug valve. The plug valve has a bore 19 therein through which a stem 20 connected to the knob 18 extends. The stem 20 has an annular shoulder 21 within a bore 22 in the lower end of the plug valve and a reduced diameter stern extension 20a. The extension has a sliding fit in a bore 23 of a safety valve 24 pivotally mounted on one end of a lever 25. The valve 24 has a sealing washer 24a thereon which is adapted to engage the lower end of the plug valve 16 to shut off the flow of ga through the plug valve. The lever 25 is pivoted to the body of the valve 13 by means of pivot 26while the other end of the lever 25 is engaged by a connector 27 pivotally mounted "ice thereon. A spring 28 normally biases the lever 25 in a clockwise direction to normally hold the valve 24 against the end of the plug valve 16. A stem 23 extends from the connector 27 to an armature 30 of an electromagnet unit 31. This magnetic unit 31 is of the type adapted to be energized by a thermocouple (not shown) heated by a pilot burner. It is held in the valve body by means of a concentric lead type of terminal member 32 extending through an aperture 33 in the valve body 13 and held therein by means of a nut 33a. A coiled compression spring 34 normally biases the knob 18 outwardly from the plug valve while a compression spring 35 biases the valve head 24 away from the lower end of the plug valve. However, the spring 28 is stronger than the spring 35 so that if the electromagnet 31 is not energized, the valve 24 will be held against the plug valve to shut off gas flow through the plug valve. The closing of the valve 24 is permitted due to the lost motion connection between the reset stem portion 20a and the lower end of the bore 23 in the valve head.

The valve construction just described is of a prior art construction but is the preferred form of the safety pilot valve on which the present invention is adapted to be mounted and form a part of the combination therewith to provide a grounding switch for an ignition circuit for a gas burner. The switch is generally designated by the reference numeral 36 and comprise a bracket portion 37 having an aperture 38 therethrough through which the connector 32 extends and is adapted to be clamped to the safety pilot 13 by means of the same nut 33a that secures the electromagnetic unit 31 in the valve. The bracket 37 has a downwardly depending portion 37a spaced from the side wall of the valve 13 and an inwardly extending portion 37b that extends from the lower end of the portion 37a to bear against the side surface of the valve 13. Extending through an aperture 39 in the portion 37a is a terminal member 40 suitably secured to an insulated plate 41 which, in turn, is secured to the bracket portion 37a by means of rivets 42. A bolt 43 is screw threaded into a threaded aperture in connector 40 and is adapted to receive a lead wire 44 from the ignition circuit of an igniter 45, shown schematically in FIGURE 5 of the drawing. A movable contact 46, in the form of a curved resilient metal with an extension 46 having downwardly extending skirt portions 46a along two sides of a straight extension thereof, is pivotally mounted on an upwardly extending portion 47 of the bracket 37. The portion 47 extends through an aperture 48 in the member 46 and has shoulders 47a upon which the member 46 rests. The curved portion of the member 46 bears against the inner surface of the bracket portion 37a and against the upper surface of the fixed contact or terminal member 40. The member 46 is so proportioned that the lower end thereof is resiliently biased against the upper surface of the fixed contact or terminal member 40 while the other end of the member 46 is positioned below the knob 18 so that axial movement of the knob 18 toward the valve 13 will cause pivoting of the member 46 and lifting of the lower end of the member 46 away from the connector 40 and against the inherent bias of the member 46.

The igniter circuit for a gas burner illustrated in FIG- URE 5 of the drawing comprises a piezoelectric current generator 49 connected to a primary coil 5t of a transformer 51 and a secondary coil 52 of the transformer connected to one terminal of the igniter and the other end of the coil 52 connected to the other terminal of the igniter. One side of the igniter 45 is grounded by a lead wire 53 while the other lead to the igniter is connected by lead 44 to the fixed contact or terminal member 40. The valve 13 is grounded by lead 54 or grounded by the pipe coupling to the valve.

Operation The manifold valve is illustrated with the safety pilot valve in its open position with the armature 3% held by the electromagnetic unit 31 and the switch is shown in the position which causes the igniter to be grounded and rendered ineffective and incapable of conducting current to the igniter even should current be generated by the piezoelectric current generator 49. Should the pilot burner become extinguished, causing the electromagnet to become rte-energized, the spring 23 will override the spring 35 and cause the valve 24 to close. To place the apparatus in operation again, it would be necessary to move the control knob 18 to a pilot ignite position and then depress the knob 18 to open the safety valve 24 and simultaneously move the movable contact arm 46 out of engagement with the fixed contact or terminal member 40 to enable the piezoelectric igniter 49 to be operated to generate a potential across the igniter 45 to create a spark for igniting the pilot burner. Once the pilot burner has become ignited and has sufficiently heated a thermocouple associated therewith, return movement of the knob 18 to its outer most position will cause the resilient curved portion of the member 46 to return the lower end thereof against the fixed contact or terminal member 40 and again render the igniter inoperative.

The detailed operation of the safety pilot valve mechanism has not been described fully as it is a conventional operation. From the above description, it is readily apparent that the inventor has produced a switch means which is easily mounted on a safety pilot valve and is of inexpensive yet reliable construction. It is also apparent that modification may be made therein without departing from the spirit of the invention. Therefore, the scope of the invention should be determined from the appended claims.

I claim:

1. An ignition shorting switch for use on a gas safetypilot valve comprising a metallic bracket shaped so as to be mountable on a valve body near a knob that is used to actuate a safety-pilot valve, a lever pivoted intermediate its ends on said bracket, one end of said lever being relatively stiff and of sufficient length to extend to the knob for actuation thereby when the knob is actuated to open the safety-pilot valve, the other end of said lever having a metallic portion extending therefrom at an angle to the longitudinal axis of the lever and resiliently and slidably bearing against a portion of said bracket so as to bias said one end toward said knob, an insulated contact and terminal member mounted on said bracket and having a contact portion normally in engagement with said metallic portion but movable out of engagement therewith when said one end of said lever is actuated by said knob.

2. An ignition shorting switch for use on a gas safetypilot valve comprising a metallic bracket shaped so as to be mountable on a valve body near a knob that is used to actuate a safety-pilot valve, said bracket having an arm extending therefrom to serve as a pivot, a metallic lever pivoted intermediate its ends on said arm, one end of said lever being relatively stiif and of sufficient length to extend to the knob for actuation thereby when the knob is actuated to open the safety-pilot valve, the other end of said lever being relatively resilient and having a portion extending therefrom transversely to a plane along the relatively stiff portion of the lever and resiliently and slidably bearing against a portion of said bracket so as to bias said one end toward the knob, an insulated contact and terminal member mounted on said bracket and having a contact portion normally in engagement with said transversely extending portion but movable out of engagement therewith when said one end is actuated.

3. An ignition shorting switch for use on a gas safetypilot valve comprising a metallic bracket shaped so as to be mountable on a valve body near a knob that is used to actuate a safety-pilot valve, said bracket having an arm extending therefrom to serve as a pivot, a metallic lever pivoted intermediate its ends on said arm, one end of said lever being relatively stifi? and of sufficient length to extend to the knob for actuation thereby when the knob is actuated to open the safety-pilot valve, the other end of said lever being relatively resilient and having an arcuate third portion resiliently and slidably bearing against a portion of said bracket so as to bias said one end toward the knob, an insulated contact and terminal member mounted on said bracket and having a contact portion normally in engagement with said third portion but out of engagement therewith when said one end is actuated.

References Eited by the Examiner UNITED STATES PATENTS 3,120,589 2/1964 Westberg 20061 ROBERT K. SCHAEFER, Acting Primary Examiner.

BERNARD A. GILHEANY, Examiner.

Claims (1)

1. AN IGNITION SHORTING SWITCH FOR USE ON A GAS SAFETYPILOT VALVE COMPRISING A METALLIC BRACKET SHAPED SO AS TO BE MOUNTABLE ON A VALVE BODY NEAR A KNOB THAT IS USED TO ACTUATE A SAFETY-PILOT VALVE, A LEVER PIVOTED INTERMEDIATE ITS ENDS ON SAID BRACKET, ONE END OF SAID LEVER BEING RELATIVELY STIFF AND OF SUFFICIENT LENGTH TO EXTEND TO THE KNOB FOR ACTUATION WHEREBY WHEN THE KNOB IS ACTUATED TO OPEN THE SAFETY-PILOT VALVE, THE OTHER END OF SAID LEVER HAVING A METALLIC PORTION EXTENDING THEREFROM AT AN ANGLE TO THE LONGITUDINAL AXIS OF THE LEVER AND RESILIENTLY AND SLIDABLY BEARING AGAINST A PORTION OF SAID BRACKET SO AS TO BIAS SAID ONE END TOWARD SAID KNOB, AN INSULATED CONTACT AND TERMINAL MEMBER MOUNTED ON SAID BRACKET AND HAVING A CONTACT PORTION NORMALLY IN ENGAGEMENT WITH SAID METALLIC PORTION BUT MOVABLE OUT OF ENGAGEMENT THEREWITH WHEN SAID ONE END OF SAID LEVER IS ACTUATED BY SAID KNOB.

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