US2969078A - Safety control device - Google Patents

Description

1 Jan- 24 196 R. L. vlcENzl 2,969,078

,SAFETY CONTROL DEVICE Filed May 8, 1957 INVENTOR. Reno L. VlceN za United Sttes Patent O SAFETY CONTROL DEVCE Reno L. Vicenzi, Milwaukee, Wis., assigner to Controls Company of America, Schiller Park, Ill., a corporation of Delaware Filed May 8, 1957, Ser. No. 657,850 9 Claims. (Cl. 137.-66)

This invention relates to a control particularly adapted to use in regulating gas ow to a heating unit having pilot and main burners.

During summer months it is desirable to positively shut down the main burner of a furnace or the like but the p-ilot flame should be maintained to keep the furnace dried out. In the past this has been done by providing a separate plug valve in the main burner gas line or by providing a switch to break circuit of the solenoid valve regulating flow -to the main burner. These approaches are somewhat costly and the present invention permits the flow to the main burner to be cut off at very low equipment cost.

The basic object of this invention is to provide a simple, effective means for preventing flow to the main burner.

Another object is to provide for summer shutdown by utilizing to a great extent the necessary parts of any safe gas control.

ln carrying out this invention a simple interrupter type safety valve is employed but is modified so the interrupter valve can be locked shut without interfering with operation of the safety valve in regulating flow which is directed only to the pilot with the interrupter valve locked. Therefore, 100% safe operation is maintained. This simple but effective concept has broad application and is easily modiiied to embrace switch operation and the like.

Other objects and advantages will be pointed out in, or be apparent from, the specification and claims, as will obvious modifications of the single embodiment shown in the drawings in which:

Figure 1 is a somewhat schematic view of the present device; and

Figure 2 shows the device with the interrupter valve locked shut and the safety valve closed.

Referring to the drawings now in detail, it will be seen that only a very simple form of ilow interrupter va'lve body 10 is shown but it should be understood that this type of construction can be incorporated in a more complex valve arrangement. Body 10 is provided with inlet 12, outlet 14 to the pilot burner and a main burner outlet 16. Safety valve 18 cooperates with seat 20 to regulate flow to both the pilot and main burners. The valve is carried on stem 22 connected to armature 24 which is adapted to be held by electromagnet 26 against the bias of spring 28 when the thermocouple (not shown) Patented Jan. 24, 1961 spring 40. As the stem moves downwardly towards the energizing the electromagnet is heated Iby the pilot flame.

When so held valve 18 will be open to permit flow to both the pilot and the main burners. This type of construction is, of course, quite old.

Safety mechanisms of this type must be reset and the present construction is of the type broadly classied as a ow interrupter type. With this arrangement the reset stern Sti is pushed downwardly by depressing cap 32 against the bias of spring 34 so the end of the stern can act against valve 18. The stern mounts on interrupter valve 36 which is biased against ange 38 on the stem by seat to block flow to the main burner and at that time the stem slides axially of the interrupter valve to finally engage valve 18 and push the valve open while resetting armature 24 to the electromagnet 26. This permits ow to the pilot burner since pilot burner outlet 14 is located between the safety valve and the interrupter valve. The pilot burner is now ignited and the heat thereof energizes the thermocouple to in turn energize the electromagnet to retain armature 24 and hold valve 18 open. If the reset stem 30 is allowed to retract before the electromagnet is suiciently energized spring 28 will close the safety valve and cut off all the ow. However, if the electromagnet retains Ythe armature then the safety valve will remain open andl movement of the stem 30 outwardly under the inuence of spring 34 will, of course, cause the stern to pick up the interrupter valve 36 and move it o its seat whereupon ow to the main burner can occur.

As thus far described the arrangement is essentially that of a basic flow interrupter valve. However, in the present case, a stop mechanism is provided in which the reset cap 32 is provided with an ear 42 on the periphery of the cap skirt which can be rotated on the stern to engage the ear under head 44 of pin 46. This prevents full withdrawal of the reset pin 30 so that the pin cannot pick up the interrupter valve 36 which is, therefore, held on its seat to prevent flow to the main burner. lt will be seen from the drawings that the safety Valve 18 is still fully operative since it can seat without interference from the pin 30.

Now then, it will be appreciated that in normal operation the cap 32 of the reset mechanism is normally positioned so ear 42 will not engage the underside of head 44 on pin 46. At this time the interrupter type reset operates in the normal way. However, if it is desired to close the furnace down for summer operation it is necessary only to push in the reset and then turn cap 32 to engage ear 42 with the underside of pin head 44 so the interrupter valve is held against its seat and flow to the main burner is cut olf without impairing the safety function of the safety valve 18 which is now employed only for controlling ow to the pilot burner. It will be seen that the control is completely safe (achieves shut oi if pilot fails) in either form of operation. The only parts required over a regular interrupter to provide the summer shutdown feature are the ear on the push pin and the headed pin.

It will be appreciated that other types of locking mechanisms could be substituted for the locking mechanism shown in the drawing. Thus, for example, a pin could be mounted transversely of the push pin 30 and adapted to be received within a slot on the inside of the housing for normal operation and to span the slot to prevent full withdrawal of the reset pin for the summer shutdown operation. Other types of locking mechanisms will readily occur to those skilled in the art and it is to be appreciated that all of such concepts come within this invention.

Similarly, it will be appreciated that there are some types of reset mechanisms where instead of using an interrupter valve such as valve 36 a switch is incorporated in circuit with the solenoid valve controlling ow to the main burner and operated -by actuation of the reset pin. The present construction is fully adaptable to that type by merely substituting a switch for valve 36.

Finally, it should be noted that this concept is applicable to valves not of the interrupter type but utilizing rather dilerent structures. One such example is seen in the copending Vicenzi et al. application Serial Number 652,427.

It View of the above remarks it will be appreciated that the present invention is not to be limited by the disclosure in the drawings but is to be limited only by the scope of the claims.

I claim:

1. A control comprising, a rst control device movable between a rst position and a second position, a second control device movable between a rst position and a second position, condition responsive means requiring resetting connected to the iirst device for retaining it in its rst position while the response condition obtains and operative to move the rst device to said second position when the condition does not obtain, reset means operatively connected to the iirst device and to the response means for resetting the response means and moving the first device to its first position, means biasing the second device to its second position, means for moving the second device to its first position upon completion of resetting the response means, and stop means for preventing movement of the second device to said first position at any time, said response means being operative after being reset to move the first device to its rst position regardless of the position of the second device.

2. A control device according to claim l in which the iirst device is a safety valve while the second device is an interrupter valve and said means preventing movement of the second device to its first position comprises means for locking the interrupter valve in its closed position.

3. A gas ow control comprising, a valve arrangement including irst and second valves movable between ow permitting and how preventing positions, condition responsive holding means requiring resetting and operatively connected to the iirst valve at all times to hold it in the flow permitting position when the response condition obtains and to move the first valve to its flow preventing position when the response condition ceases, reset means for resetting the holding means, means connecting the second valve and the reset means whereby the second valve is held in the tiow preventing position during the resetting operation and is moved to the flow permitting position upon completion of the resetting, and stop means for preventing movement of the second valve to the flow permitting position after completion of resetting of the holding means, said stop means being effective only after the reset means has moved to a position in which the reset means is unable to aiect peration of the rst valve.

4. A gas flow control according to claim 3 in which the second valve is carried by the reset means and must be closed before the reset means is operative to reset the holding means.

5. A fluid ow control device comprising, a pair of valve means, condition responsive means requiring resetting and connected to one of said valve means for retaining said one valve means open in response to a condition and for closing said one valve means when the condition no longer obtains, reset means for resetting the condition responsive means and operative to open said one valve means during the resetting operation, the other of said valve means being operatively connected to the reset means for movement thereby to its open position upon completion of the resetting operation, and means for optionally preventing movement of said other valve means to its open position, said preventing means being operative to prevent movement of said other valve means to its open position only after the reset means has moved to a position in which it is unable to eect movement of said one valve means to its closed position when said response condition no longer obtains.

6. A uid ow control device comprising, rst and second control members moveable between flow preventing and flow permitting positions, thermoelectric safety means including an electromagnet and an armature normally occupying retracted positions and moveable to attracted positions wherein the armature is retained in response to a condition, one of said control members being operatively connected to said safety means; reset means for resetting the electromagnet and armature to attracted position and for moving said one of the control members to its flow permitting position for retention in such position so long as the response condition obtains, the safety means acting to move said one control member to its iiow preventing position when the response condition does not obtain, means biasing the second control member to its flow preventing position, means operative upon completion of the resetting to move the second control member to its flow permitting position, and means for overcoming the last named means whereby the second control member is retained in its ow preventing position, the operation of the safety means being unaiected by the position of the second control member.

7. A control comprising, rst and second control devices each moveable between irst and second positions, means biasing each device to its second position, condition responsive means requiring resetting connected to the first device for retaining it in its iirst position while the response condition obtains, reset means operatively connected to the iirst device and to the response means and moveable in one direction for resetting the response means and moving the irst device to its rst position, means operative during motion of the reset means in another direction upon completion of the resetting of the response means for moving the second device to its first position, and means for preventing movement of the second device to said iirst position at any time, said iirst device being moveable to its second position at all times except during the resetting operation.

8. A gas ow control comprising, a valve body having an inlet connected to a main burner outlet and a pilot burner outlet, a safety valve controlling flow to both outlets, means biasing the safety valve closed, condition responsive means requiring resetting and operatively connected to the valve to retain it in its open position in response to a control condition and to release it for closing movement when the control condition no longer obtains, an interrupter valve located downstream of the pilot burner outlet for controlling ow to the main burner outlet, means biasing the interrupter valve to its closed position, reset means moveable in one direction to open the safety valve and reset the condition responsive means, means carried by the reset means to engage the interrupter valve during return movement of the reset means, and means operable only after the reset means has returned to a position in which it is unable to eiect operation of the safety valve for preventing engagement of the engaging means and the interrupter valve.

9. A control according to claim 8 in which the reset means includes a reeiprocable plunger and the preventing means comprises a stop to limit return motion of the plunger.

References Cited in the tile of this patent UNITED STATES PATENTS Great Britain Aug. 15, 1956

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