US2639094A - Interlocking switch structure for electrically operated valves - Google Patents

Description

y 19, 1953 c. c. YOUNG 2,639,094

INTERLOCKING SWITCH STRUCTURE FOR ELECTRICALLY OPERATED VALVES Filed July 14, 1949 2 Sheets-Sheet l [17 fez-2L0? May 19, 1953 c. c. YOUNG 2,639,094

INTERLOCKING SWITCH STRUCTURE FOR ELECTRICALLY OPERATED VALVES Filed July 14, 1949 2 Sheets-Sheet 2 I .EUVEHLQF ckagle-s'l bug Patented May 19, 1953 UNITED STATES PATENT OFFICE INTERLOCKING- SWITCH STRUCTURE FOR.

ELECTRICALLY OPERATED VALVES Cyril Charles; Young, Kansas City Mo;

Application July 14, 1949, SeriaLNo. 104,708

2' Claims;

This invention relates generally to. an. electrical switch and more particularly to a novel and improved interlocking switch structure for an electrically operated valve whereby the valve may be interlocked electrically in a contro1.sys-

tem. circuit. It may be noted that. the present invention finds a particularly useful application when used on valves employed in a control system. for a combination oil and gas burner unit whereby the interloclring, switch arrangement precludes concurrent operation of both a main gas valve and an oil valve.

In my copending application United States Serial No... 41319, filed September 11, 1948, now Patent No. 2,547,611, there is disclosed and claimed a. novel combination gas and. oil burner and control therefor which will permit a heat.- ing plant. to be efiiciently operated either by an oil; fuel or by a. gas fuel. This type of burner unit. has. the. advantage that for moderate outdoor temperatures, the heating of the building or residence in which the unit is installed may be. accomplished solely by a. gas fuel, or upon the occurrence of extreme weather conditions, the. unit may be operated to burn an oil fuel to. adequately supply the required amount of heat without constituting. an. excessive demand upon the city gas supply.

The present application specifically relates to certain structural improvements in an electrically operated valve incorporated in the control system disclosed; in. the acknowledged copending application.

It is anobject of this invention toprovide an improved electrically operated valve which may be readily incorporated ina combination oil and gas. heater. system and interlocked electrical-1y in a control circuit so as to precludesimultaneous opening of a plurality of valves.

Another object of this invention is to provide an interlocking switch structure for an electrically operated valve which takes the form of an unusually simplified arrangement whereby a plurality of electrically operated valves may be interlocked in a control circuit associated therewith.

According to the general features of the presentv on with a portion thereof normally contacting the firstswitchcontact. A tab ofelectrically-nonconductive material" projects from the free end of the switch contact blade in cooperative driving relationship with a portion of a plunger type valve stem embodied in the electrically operated valve. Appropriate lead terminals are providedon the contact board which are electrically connected to the switch contacts, whereby the valve may be electrically interlocked in an appropriate con trol' circuit leading to av second electrically operated valve...

Many other features; advantages and objects: of the present invention will become manifest to those versed in the art upon making reierence to the detailed description which follows and the annexed sheets of drawings in which:

Figure 1 is a schematic diagram of an electrical control system for. a combination gas and oil burner embodying an electrically operated valve in accordance with this invention;

Figure 2* is a plan view partly broken away and with parts in section showing an electrically operated valve in accordance with this invention; and

Figure 3 is a cross-sectional view with parts in elevation taken on line IIIIII of Figure 2.

As shown on the drawings:

Although the present invention relates to structural improvements in an electrically operated valve, it is believed that a particularly clear understanding of the invention may be had by considering the application of the principles embodied therein with respect to'the control circuit of a combination gas and oil burner unit.

Accordingly, although not specifically limited thereto, the present invention will be described in connection with its adaptation to suchan environment.

As is more. clearly set forth in my acknowledged copending application, a combination; gas and oil burner unit may be provided with. a blower ill driven by an electrical motor H: for supply- 7 ing adequate amounts of air necessary to support combustion when the burner unit is operated on an oil cycle.

The combmation gas and oil burner unit efiects gas fuel, which is supplied under the control of an electrically operated vaporizer gas valve 12. The main supply of iuel oiI supplied for com-- busti'on in the combination oil and gas burner unit is controlled by an electrically operated oil valve l3. The supply of gas fuel for the main gas burner of the combined gas and oil burner unit is controlled by an electrically operated gas valve l4.

The initiation of operation of the combined gas and oil burner unit on either a gas burning or an oil burning cycle may be automatically controlled in any desired manner and details of a particular arrangement for cycle selection are explained in greater detail in my copending application Serial No. 764,698, filed July 30, 1947, now Patent No. 2,552,302.

The cycle selection arrangement shown in Figure 1 corresponds identically to that disclosed in the acknowledged copending application Serial No. 764,698, whereby selection of the gas or oil burning cycle is controlled by an outdoor thermostat l6 and the intermittent operation of the combination gas and oil burner unit on the selected cycle is controlled by a room thermostat IT.

The control circuit may be operated from any suitable source of power indicated as line terminals L1 and L2 and, if such source is of the alternating current type, may be stepped down to a suitable voltage by a transformer l8.

The outdoor thermostat I6 is preferably of the snap-action type wherein a switch blade |6a of the thermostat selectively engages either the contact G or a contact depending upon whether or not the outside temperature is above or below a predetermined value. For purposes of illustration, it is assumed that the outdoor thermostat I6 will have its switch blade |6a rest across its neutral terminal N to the terminal G for all outdoor temperatures above a predetermined value and will have the switch blades |6a rest across the neutral terminal N and the terminal 0 for all outdoor temperatures below such a predetermined value. The shifting of the switch blades |6a between the terminal G and the terminal 0 then effects the operation of the burner unit respectively on its gas and its oil burning cycle.

The indoor thermostats I! may be of a conventional type and is illustrated as comprising a thermostat of the three-wire type, including a heating element Ila and a pair of contacts llb which are closed whenever the room temperature is below a predetermined value and which are open whenever the room temperature exceeds a predetermined value.

The vaporizer gas valve I 2 may be of any conventional electrically operated construction and for illustrative purposes may be considered as a solenoid controlled type valve.

According to the present invention, the main gas valve |4 takes the form of a conventional plunger type valve including a body l9 defining an apertured seat |9a through which a fluid such as a gas fuel may flow.

A leather disk washer 20 which is supported and positioned by a seat washer retaining screw 2| threadedly engageable with a valve disk and swivel assembly controls the aperture in the seat I 9a.

According to conventional practice, the main gas valve I 4 may be provided with an upper seat 22 and a diaphragm stem seal 23. A plunger type valve stem 24 passes through the diaphragm stem seal 23 and threadedly receives the valve disk and swivel assembly.

The operating mechanism for the electrically operated main gas valve I4 is contained within a housing 26 which may be integrated with a collar 21 by means of fasteners 28. The collar 21, in turn, is attachable to the body I9 of the valve.

An upper portion of the collar 21 is suitably formed so as to define an internally threaded bore for receiving a generally cylindrical permanent magnet 29 appropriately constructed so as to freely pass the valve stem 24 therethrough.

The valve stem 24 is provided with a circular armature portion 30 which is arranged in proximity to the permanent magnet 29. The valve is normally held closed by the downward pull of the permanent magnet 29 on the circular armature 30 attached to the valve stem 24.

The main gas valve I4 is a direct operated snap-acting valve and is actuated by a bi-metal strip motor 3|. The motor 3| may be heated by a low voltage heater element indicated at 3|a. When a low voltage current passes through the heater element 3 la, the heat from the heater element 3|a causes the bi-metal motor 3| to warp upward, thus applying a lifting force on the valve stem 24 through an arm extension 3|b arranged in cooperative relationship to a collar 32 aflixed to the valve stem 24.

When the closing pull of the permanent magnet 29 is overcome by the bi-metal motor 3|, the

valve stem 24 moves upwardly with a positive snap-action. When the bi-metal motor 3| cools, the valve stem 24 carrying the collar 32 and the armature 30 will be forced downwardly. When the armature 30 is near the permanent magnet 29 it is pulled downward quickly so as to close the valve l4 with a snap action.

The operating mechanism of the main gas valve l4 may also be provided with a motor timing adjustment indicated generally by the reference numeral 33, the details of which are not necessary to the present invention.

It will be also apparent that a sleeve 34 may be provided in the upper portion of the operating mechanism for carrying a bushing 36 adapted to guide the valve stem 24 in its vertical reciprocatory movements.

A particular feature of the present invention resides in the provision of an interlocking switch structure indicated generally by the reference numeral 31 and adapted to be incorporated in the operating mechanism of the main gas valve 4. The interlocking switch structure 31 includes a pair of posts 38 which may be affixed to the housing 26 and upon which may be mounted a contact board 39 preferably made out of an electrically non-conductive insulating material. A lower switch contact 40 is provided on the contact board 39 and in the preferred embodiment herein shown preferably takes the form of a conventional button-type electrical contact which may be firmly allixed to the contact board 39.

An upper contact 4| is also provided which preferably takes the form of a flexible blade made of electrically conductive material and is mounted on a spacer 42 made of an electrically non-conductive insulating material carried by the contact board 39. The switch contact 4| is thus carried in spaced relationship to the lower switch contact 40 but, because of the inherent resilience of the flexible blade comprising the upper switch contact 4|, the lower and upper switch contacts 40 and 4|, respectively, will normally be in closed circuit position.

A tab 43 made of a suitable electrically nonconductive material is affixed to the free end of the flexible blade comprising the upper switch contact 4| and is arranged to lie in cooperative relationship between the circular armature 3.0- and the collar t2. afilxed to. the valve stem 24... When the. valve stem. 2:4 is. actuated upwar m. the. armature or will engasingly abut the tab 43; andv flex: the. upper switch contact M upward-iv, therebv breaking. the electrical. cir-v cuit connection between the upper switch con.- taot it and the lower switch. contact 4a..

The contact board is provided with a suit:- ablelead terminal. All. which. be electrically connected to. the lower switch. contact Ml bv means of; an electrically conductive. strip 46.=.. A

lead terminal: 411. is also. provided which. may be electrically connected to; upper switch contact 41 by means. of a stri 48:. A third terminal 49; is also provided and may be. used. to provide. a connection for an electrical lead 585 associat ed with. the bi-metal motor 31. The housing: 2.5. may be provided, with. a. suitable side aperture as at at to receive the electrical conduits which must enter the op ratin mechanism for electrioal connection to theterminals. 4.4... 4;! and. 4&-

Referring again to Figure 1,, themain g s.- valve 14 is shown in a circuit; connection efiecting a, cooperative interlocked. relationship with the.- oil valve. Hi.

In on particular type of installation which. is. herein described by way oi. illustrative example, an, oil valve 13. is employed; whichv preferably in corporates time delay characteristics, in its. operation, that is, it will. notinitiate. the. flow of; an oil fuel medium to the. combination, as. and, oil burner unit until. a. substantial predetermined interval of time has. elapsed after its original energization and, conversely, it will continue tov supply an oil. fuel m ium to the comb na gas and oil burner unit for a, limited periodof time after its deenergization. The electrically operated fuel oil valve l3; may constitute anyone. of several well known forms and for illustrative. purposes has been; shown as mp s a, heater type valve. including an electrical. heater l3a. The. valve i3; is. further provided with; a bi.- metallic element. i312 which operates an actuating bar we when it is heated by the heater el m nt [3a.

The actuating bar; l.-3.c. is; cooperativelyassociated with a pair of interlocking switches which. are indicated generally at 52' and 53. The stem I3d of the valve I 3 is arranged to actuate the elements aforementioned in a. predetermined sequence, both upon the energization of the fuel oil valve l3 and upon the deenergization thereof.

As is schematically indicated on Figure I, the desired sequence of operation is that a short time after the original energization of the heater element 3cc the actuating valve l 3c effectsthe opening of the contactsof switch 52 ancl=the-closing of the contacts of switch 53-. After astill further time interval, the actuating barl=3cengages the stem l-3d ofthevalve l-3 to open the valve l3 to permit fuel oil to be supplied to the combination gas and oil burner unit.

Upon deenergization of the heater element [3a, the sequence of operation reverses. The valve stem l3d is first released to its closed. position and then after a predetermined time delay, the switch 53 is actuated to its open contact position while the switch 52 is actuated to its closed contact position.

By virtue of the provisions made in accordance with the present invention, the electrical control circuit between the fuel oil valve 13 and the main gas valve I4 is completely interlocked so irrespective of how one of the valves may have been opened, simultaneous operation by electrical and oil burner unit.

means oi. both. the gas valve t4 and. the; oil valve. is is pr cluded,

For example. it. may be: noted that the vapon izer gas valve. ti and the blower motor III; are concurrently energized by theclosing of; the; normolly opened. contacts or the.- switch. 53.: subsequent to the cn-ergization oi the heater coillilo oi the electrically operated oil valve l3. Hence. it is assured that the vaporizer gas valve. IE will be opened whereupon. gas will be supplied to; the vaporizer burner of the combination gas and oil burner unit. to provide. a. suitable high temperaux-e. zone for vaporizing, any fuel. oil supplied through the oil valve I13 to the combination gas Simultaneous operation. of the. blower t8; will also be: assured. The time delay incorporated in the mechanism of the eleotrically operated; oil valve t3. insures that the. oil will. not be supplied to the high temperature-zone of, the combination gas; and oil burner unit. untilpro-percombustion conditions are. attained.

At the same, time, the opening of the contacts; of the normally" closed switch 5%, which. will be: seen to. be. connec ed in the energization ircuit of the main gas valve l-e, insures that the: main gas valve M will remain deenergized and; thus will be in its closed. position. Accordinglvi r spective of other conditions in,- the circuit, the; main gas valve l4 cannot be opened; when the fuel oil valve.' 13 ha 'been energized.

It should be further noted that, if the oil. valve i3. is operated manually as might well occur; un-

that operating conditions subsequent to. an electrical current interruption, or if the oil valve is jamme p n b cause of mechanical difiicul ie valve l3, the electrical control circuit, between the fuel oil valve I3. and the main gas valve. I4, is

completely interlocked.

It may be. noted that the provision of the interlocking switch structure contemplated. by thepresentv invention permits the effective utilization of additional; safety devices in. a. control circuit similar to that adap ed: as in, the present embodiment for a combination gas and oil burner unit. For example, a safety-switchunit 54 may be associated with. the blower l0 and connected: in the.- energizing circuit of the heater element. lilo. of;

the. electrically operated fiueli oil. valve 13.. The. switch. 54may'be of well known construction. and may be associated with the. blower motor I l in such amanner that aslong as the motor isfunc tioning normally, the contacts of the switch 54 will remain closed. However, when a failure of the blower motor I l occurs, the switch 54 will open and will result in the deenergization of the heater coil [3a of the fuel oil valve [3 and hence a closing of the fuel oil valve I 3.

The electrical control circuit may also be provided with a pilot flame responsive switch indicated generally by the reference numeral 56. The pilot flame switch operates in a conventional fashion to maintain a pair of switch contacts closed as long as the pilot flame for the combination gas and oil burner unit is burning and to open such contacts in the event of failure of the pilot flame produced by a pilot flame unit associated with the combination gas and oil burner unit. The contacts of the pilot flame switch 56 may be connected in the common leads included in the energizing circuits of both the fuel oil valve I 3 and the main gas valve 14. Accordingly, upon the failure of the pilot flame, the pilot flame switch 56 will open its contacts and prevent the operation of either the fuel oil valve l3 or the main gas valve [4.

The cooperation of the outdoor thermostat l6 and the indoor thermostat I! with the remaining elements of the control circuit is identical to that employed in my above referred copending application. When the outdoor temperatures are below a predetermined value, circuit connections are complete as illustrated in Figure 1 through the terminal of the outdoor thermostat Hi to energize the heater element l3a of the electrically operated fuel oil valve 13 whenever the indoor thermostat I1 is calling for heat by closing of its contacts. When the outdoor temperature is above such predetermined value, the outdoor thermostat I6 completes an energization circuit through its contact G for the main gas valve l4 whenever the indoor thermostat l1 calls for heat by the closing of its contacts llb.

From the foregoing description it will be apparent that the present invention provides an improved and simplified electrically operated valve construction employing an interlocking switch structure which makes such a valve adaptable for incorporation in an electrical control circuit incorporating several valves which must be operated in an interlocking relationship.

It will be understood, of course, that a person skilled in the art might suggest various minor modifications to the structure herein described by way of preferred embodiment and illustrative example only, however, I do not propose to be limited to the precise details herein set out for the sake of clarity but wish to embrace within the scope of this patent all such modifications as reasonably and properly fall within the scope of my contribution to the art.

I claim as my invention:

1. An interlocking switch arrangement for precluding simultaneous opening of electrically operated valves comprising, in combination, a first electrically operated plunger type valve, a second electrically operated plunger type valve, electrical operating means for each of said valves, a first electrical switch on said first electrically operated plunger type valve, a second electrical switch on said second electrically operated plunger type valve, said first switch including upper and lower switch contacts, at least one of said contacts comprising a flexible blade made of electrically conductive material so that the contacts may normally assume a closed circuit position, a tab of electrically non-conductive material disposed on the end of the flexible blade switch contact whereby the flexible blade switch contact may be cooperatively associated with a portion of the plunger of said first valve for actuation thereby to an open position upon reciprocal movement of the valve plunger, lead terminals on said first switch electrically connected to said upper and lower switch contacts, said second switch including at least one pair of contacts normally biased to a closed contact position, means associated with the stem of said second valve to actuate said second switch contacts to an open position upon opening movement of said second valve stem, lead terminals electrically connected to said second switch contacts, and leads between the terminals on said first and second electrical switches in series connection with the electrical operating means of said first and second electrically operated, valves, whereby said first and second electrical switches may be interlocked electrically to preclude simultaneous opening of said valves.

2. In a control system for a combined gas and oil burning heater of the type including a first electrically operated valve for controlling the supply of gas to the heater, a second electrically operated valve for controlling the supply of oil to the heater, a thermostat and circuit means controlled by the thermostat for selectively energizing the first or second valve, the improvement of an interlocking switch structure for the first electrically operated valve comprising a contact board, a first switch contact carried by said board, an insulating spacer on said board, a flexible switch contact blade carried by said spacer with a portion thereof normally contacting said first switch contact, a tab of electrically nonconductive material projecting from the free end of said blade into cooperative relationship with a portion of the stem of a valve and lead terminals on said contact board electrically connected to the switch contacts, whereby the interlocking switch structure may be electrically connected in said circuit means to preclude simultaneous electrical operation of the first and second electrical operated valves thereby insuring that only oil or only gas be supplied to the combined gas and oil burning heater.

CYRIL CHARLES YOUNG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,819,459 Doherty Aug. 18, 1931 2,265,648 Kopp Dec. 9, 1941 2,372,436 Landon Mar. 27, 1945 2,406,246 Ogden Aug. 20, 1946 2,409,112 Dillman Oct. 8, 1946 2,446,834 Kaufman Aug. 10, 1948 2,463,699 Klug Mar. 8, 1949

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