US2048162A - Valve control system - Google Patents

Description

J. P. KRIECHBAUM VALVE CONTROL SYSTEM Filed Ma 5, 1934 July 21, 1936.

wv nv M QEQM F 3 3 mm .mg m m ow 3 mm m. Km NN P n Patented July 21,. 1936 VALVE coN'raoL srs'rnm John P. Kriechbaum, Minneapolis, Minn, as-, signor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application May 5, 1934, Serial No. 724,146

16 Claims. (Cl. 23674) The present invention relates to an automatic control system'by which a plurality of valves may be controlled and has particular utility in connection with the control of a plurality of 5 valves whichcontrol the supply of fuel to a heating device such as a gas burner.

One ofzthe :objects of the present invention is the provision of a control system, including a member movable back and forth along 'apredel termined path vof travel in response to changes in a condition, together with means by which the control member sequentially opens a plurality of valves upon-changes in the value of acondition to, which theimovable member responds and se- 15 quentially closes the valves upon restoration of said condition, the'arrangement being such that each of the valves is closed at a different value of the condition than that at which they. are opened.

- 2 In controlling the supply of fuel to a. burner and particularly to agas burner, it is often desired to initially supply a relatively small amount of fuel upon small deviations of the value of the controlling condition. However, most gas burn- 25 ers while allowing a relatively great throttling of the gas supply when the burner is already in operation require a larger initial supply of gas thereto in order to give proper ignition. As a result, the initial supplyof gas must berelatively large and it often happens that this large initial supply of gas is larger than it is desired to burn continuously until the value of the controlling condition has deviated from the desired value by a considerable amount. It has there- 35 fore been proposed to provide an arrangement whereby upon a demand for a relatively small amount of fuel, a large a'mountof fuel will be momentarllysupplied to provide for proper ignition and thereafter the supply of fuel will be decreased-to an'amount corresponding to the demand. Thepresent invention provides an improved-system whereby such operation may be obtained."

A -further object *of'the'invention is the provi- 5- sion=of 'a'control system by which a pair of valves are'moved to openposition upon a demand for a relatively-sm'all flow of fluid. together with means controlled by movement of one of the valves *tdopen position for-closing the other of 56 the valves whereby one of the valves is momentarily opened to provide a' large initial flow of fluid and is then quickly closed'to reduce the flow of fluid to an amount corresponding to the demand. The valves are preferably of the 55' electrically operated type and the momentary means controlled by the first valve when moved to open position for closing the second valve, 0 together with means for again opening the second valve and maintaining the same open upon an increase in the demand for fluid flow.

Other objects of the invention include the provision of a complete system of the class above described which system includes a single-pilot switch responsive to the condition of a pilot burner' for igniting a main burner the flow of fuel "to which is controlled by a pair of valves one of which is momentarily opened upon an initial demand for a small amount of fuel.

Another object of the invention'comprises the provision ofa system of the nature-defined above in which all of the apparatus and particularly the two valves are standard equipment readily available on the market and are arranged, by the simple addition of a single switch controlled by one of the valves, to give a momentary opening of the other of the valves upon an initial demand for a relatively small flow of fuel to the burner. I

Other objects of the invention will be found in the following description, the accompanying drawing and the appended claims.

v is connected to ,a gas supply main II by means of branch pipes l2 and I3. The flow of gas through gas pipe I! is controlled by a first electrically operated valve l4 and the flow of gas through the branch pipe I! is controlled by a second electrically operated'valve I 5. The gas issuing from main burner Ill is adapted to be ignited by a pilot burner it which is connected to gas'main II by means of a pilot pipe i1.

The electrically opera-ted'valves l4 and I! are .diagrammatical representations of commercial valves of well-known construction and both of these valves are identical in their details. The valves l4 and i5 include .valve stems- 26 and 20awhich are normally biased to valve closing position by means of coiled springs 2| and 2|a.

The-valve stems 20 and 20a are adapted to be lifted against the bias of their springs 2| and 2 la by means oflevers 22 and 221: which are pivoted at pointsindicated at 23 and 23a. The valve i4 is operated by a rotary electrical motor 24 which comprises a field winding 25 and a rotor 26. Rotor 26 drives a gear 21 through a gear and .pinion assembly 28 and a rotor pinion 23. Valve I5 is operated by a'motor 24a which com-' prises a field winding 25a and a rotor 26a. Rotor 26a is adapted todrive a gear 21a through a gear and pinion assembly 28a and a rotor pinion 29a.

The gears 21 and 21a respectively carry crank and 2|a close the valves l4 and l5 and rotate the gears 21 and 21a. and the other gears and pinions associated therewith, as well as the motor rotors, in the reverse direction.

The gears 21 and 214 are carried upon shafts 33. and 331: which operate cams 34 and 34a through suitable slip friction connecting means.

Referring to Fig. 2 of the drawing, it will be seen that the shaft 33 is provided with .a collar against which the cam 34 is pressed [by means of a coiled spring 36. .Washers 31 are interposed between coiled spring 36 and cam 34 and between collar 35 and cam 34. The other end of the coiled spring 36 is confined against longireceived in a suitable opening in shaft 33. The

in its movement, the slip frictional connection above described will allow continued movement of shaft 33. The cam 34a is connected to shaft 33a. through a similar slip friction connecting means.

. 4 Cams 34 and 34a are provided with notches 40 and 40a which cooperatewith stop pins 4| and Ma, whereby the movements of cams 34 and 34a are/restricted. Cam 34 operates a switch arm 43fwhich is-adapted to be moved into engagement witha stationary contact 44 but is normally biased from engagement therewith by means of a spring 45. Similarly, cam-34a is adapted to operate a switch arm 43a that is movable into engagement with a contact 44a but is normally biased from engagement therewith by means of a spring 45a. Stop pins 46 and 46a limit the movement of switch arms 43 and 43a away from their cooperating contacts 44 and 44a. The switch arm 43 and contact 44 comprise a first holding switch and the switch arm 43a and contact 44a comprise a second holding switch. From an inspection of the drawings, it will be noted that the arrangement is such that upon initial movement of cam 34 in clockwise direction, switch arm 43 will be moved into engagement with contact 44. The stop pin 4| will thereafter prevent further clockwise rotation of cam 34 and, about this time, crank pin 30 will engage hooked link 3| to begin raising valve stem 26 of valve M. The holding switch comprised by switch arm 43 and contact 44' istherefore closed upon initial movement of gear 21 in valve opening direction. Similarly, the sec- Y ond holding switch comprised by switch arm" 43aand contact 440. is moved to closed position upon initial movement of gear 21a in valve opening direction.

'Valves l4 and I5 are hereinshown as controlled by a' condition responsive element in the form of a bimetallic element 50 which responds to the temperature of a room or space to be heated. One end of the bimetallic element 56 is held stationaryand the other end thereof conengages switch arm 56 and lastly switch arm 5| disengages contact 55.

Power for field winding 25 is supplied by a step-down transformer 59, having a low voltage secondary 60 and a high voltage primary 6| connected to suitable-line wires 62 and 63. The ca-:

pacity of the transformer-53 is suihcient to operate motor 24 but is insuflicient to additionally operate motor 24a. Power for motor 24a is supplied by a similar transformer 64, having a low voltage secondary 65 and a high voltage primary 66 which is also connected to the line wires 62 and 63. The system also preferably includes a pilot switch comprised by a bimetallic element 61 which engages a contact 68 whenever the pilot. burner I6 is operating properly. Such pilot switches are well known in the art. 9' th. e

The lever 22 supports a mercury switch arrangement being such that mercury switch 63 is moved to open position only when valve l4 has been completely or substantially completely opened and is closed at all other times.

The remaining circuit connections will be described in detail under the heading fOperation".

Operation with the parts in the position shown, the room temperature is at or above the desired point so that both, the first and second gas valves l4 and I5 are closed. The main burner I4 is inoperativev but the pilot bumer I6 is operating properly as indicated by the fact that bimetallic element "61 is engaged with its contact 66.

Now as the room temperature falls, switch arm 5| will engage contact but such engagement of switch arm 5| with contact 55 does not complete any initial energizing circuits.. Upon further fall in space temperature, switch arm 52 will engage contact 56 whereupon fleld windings 25 and 25a will be simultaneously energized.

The circuit for fleld'winding 25 is as follows:

secondary of transformer 53,' wire 16,- bi- 52', contact 56, wire 12, wire 13, wire 14, field winding 25, and wire 15 to the other side of secondary 60. The energizing circuit for field winding 25a is as follows: secondary 65 of transformer 64, wire 15, wire 10. bimetallic element 51, contact 68, wire 1|, bimetallic element 50', switch arm 5|, switch arm 52, contact 56, wire 12, wire 11, mercury switch 69, wire 18, wire 19, field winding a, and wire 80 to the other side of secondary 55.

Gears 21 and 21a will thereupon be rotated in clockwise direction. The first and second holding switches comprised by switch arms 43 and 43a and contacts 44 and 44a will first be closed in the manner heretofore described. Engagement of switch arm 43 with contact 44 establishes a holding circuit for field'winding 25 as follows: secondary 60, wire 10, bimetallic element 61, contact 58, wire 1|, bimetallic element 5|), switch arm 5|, contact 55, wire 8|, contact 44, switch arm 43, wire 82, wire 14, 'field winding 25 and wire 15 to secondary 50. Engagement lic element 50, switch arm 5|, contact 55, wire toward open position. when valve I4 is completely or substantially completely opened, mercury switch 69 will be moved to open circuit position whereby the energizing circuit for field winding 25a will be interrupted. Valve l5 will therefore close and its holding switch will be returned to the open position shown in the drawing. Valve It will remain in its open position by reason of stalling of its motor 24 and will remain in such open position until switch arm5| disengages contact 55. i

From the foregoing description, it will be seen that upon an initial .fall in room temperature,

' demanding a relatively small fiow of gas, both flow of gas to the main burner ||i which fiow of gas is reduced in accordance with the demands by the closing of valve l5. The large flow of gas produced by the combined openings of valves l4 and i5 provides a full fiow of gas to main burner l0 which is readily ignited by the pilot burner l6. After'the main burner I0 is placed inoperation, the reduced fiow of gas allowed by valve l4 will remain burning properly since ignition has already been established.

If there should be a continued fall inroom temperature so as to bring switch arm 53 into engagement with contact 51 and then bring switch arm 54 into engagement with contact 58, field winding 25a. of gas valve l5 willagain be energized by a circuit as follows: secondary 65. wire 15, wire 10, bimetallic element 51; contact 68, wire 1|, bimetallic element 55, switch arm 5|, switch arm 54, contact 58, wire 83, wire 19, field winding 25:: and wire 80 to the other side of secondary 55. The holding switch comprised by switch arm 43a and contact 44:: will be quickly closed as previously explained and will establish a holding circuit for field winding 25a as follows: secondary 65, wire 15, wire 10, bimetallic 51, wire 84, contact 44a, switch arm 43a, wire 85,. field winding 251a and wire 80 to the other side of secondary 55. The gas valve I5 is therefore moved to open position upon a further fall in room temperature so as to again give a full supply of gas to the main burner l0. Valve l5 will now remain open until the roomtemperature is restored sufliciently to move switch arm 54 from engagement with contact 58, thereby breaking the energizing circuit for field winding 25a, and until switch arm 53 disengages contact 51 whereupon the holding circuit for field winding 25a is interrupted. When the room temperature has thus been partially restored and both the energizing and holding circuits for field winding 25a are interrupted, valve l5 will close and its controlling mechanism will return to the position shown in the drawing. If the room temperature should thereafter again decrease so as to bring switch arms 53 and 54 into engagement with contacts 51 and 58, gas valve l5 will again be energized as previously explained. However, if the room temperature continues to increase, switch arm 52 will move from engagement with contact 58 and interrupt the energizing circuit for gas valve |4. Gas valve M will remain open however until the room temperature is completely restored so as to move switch arm 5| from engagement with contact 55 to interrupt its holding circuit. 30

If the pilot burner l6 should become extinguished at any time, the pilot switch defined by 81-58 will open and prevent opening of gas valves i4 and I5 or prevent their remaining open if they should be open when this occurs.

The levers 22 and 22a may. of course operate secondary air dampers in the usual manner if desired. a

From the foregoing description, it will be seen that the present invention provides a simple system utilizing standard parts and requiring merely the addition of the single mercury switch 65 in order to provide a system wherein two valves are simultaneously opened upon a demand for a small flow of fluid and one of them is thereafter immediately closed whereby a large initial supply of fiuid is provided and the supp y is then reduced in accordance with the demand. Furthermore, if there should thereafter be a demand for a larger supply of fluid, the second valve is again opened and maintained open. Further, it will be noted that the first and second valves are sequentially opened upon changes in the value of a condition in one direction and are sequentially closed upon restoration of the condition but at values of the condition which are diflercnt than those at which the valves were opened.

It is obvious that the invention is applicable to systems other than that disclosed herein and that many changescan readily be made by those 60 1. In combination, a movable member adapted to move back and forth along a predetermined path of travel, a first valve, a second valve, connections between said member and first valve for opening the'latter when said movable member reaches a first point in its path of travel while moving in a first direction and'for closingthe same when said movable member reaches a second point-in traveling in a second direction, connections between both of said valves and said -movable member for also opening said second.

valve when the-movable -member reaches said travel when moving in said first direction and for closing said second valve when said movable member-reaches a fourth point in its path of travel upon movement in said second direction,

all four of said points being spaced one from another.

2. In combination, a movable member adapted to move along a predetermined path of travel, first and second valves, and connections between said movable member and valves for opening said first and second valves at a first point, then closing said second valve, and for again opening said second valve at a second point as said movable member moves along its path of travel in one direction and for closing said second and first valves when said movable member reaches third and fourth points in its path of travel upon return movement of said movable member, said movable member passing through said third and fourth points in moving to said first and second points when moving in said first direction.

3. In combination, first and second switches, means responsive to a condition for sequentially closing said switches in the order named upon continued change of said condition in a single direction, a first electrically operable valve, a third switch moved to open position by said valve when the valve reaches open position, a second electrically operable valve, an energizing circuit for said first valve controlled by said first switch, an energizing circuit for said second valve controlled by said first switch and third switch in series whereby said second valve is opened momentarily. upon closure of said first switch, a second energizing circuit for said second valve controlled by said third switch and holding circuits for said valves controlled by said condition responsive means.

- 4. In combination, means responsive to the value of'a condition, three switches sequentially closed thereby upon continued change of said condition in one direction, a first electrically operable valve, a fourth switch which is closed and a fifth switch which is opened by said first valve upon opening thereof, an energizing circuit for said first valve controlled by said second switch, a holding circuit for said firstvalve controlled by said first and fourth switches, a second electrically operable valve, a first energizing circuit'therefor controlled by said second and fifth switches in series, and a second energizing circuit for said valve controlled by said third switch.

5. In combination, means responsive to the value of a condition, four switches sequentially closed thereby upon a change in said condition in a single direction, a first electrically operable valve, a fifth switch moved to open position and a sixth switch moved to closed position by said valve upon opening thereof, a second electrically operable valve, a seventh switch closed by the second valve when opened, an energizing circuit for said first valve controlled by said second switch, .an' energizing circuit for said second valve controlled by said second and fifth switches in series whereby said second valve is opened momentarily uponclosure of said second switch, a holding circuit for said first valve controlled by said first and sixth switches, a second energizing circuit for said second valve controlled by said switches in series.

6. In combination, a condition responsive switch, a first electrically operable valve, 9. second switch, means associated with said first valve and second switch by which the second switch is moved to open position as a result of opening of said first valve, a second electrically operable valve, first and second transformers for said first and second valves, each transformer having sumcient capacity to operate its respective valve but insufilcient capacity to operate. both of said I valves, a circuit comprising said first transformer, condition responsive switch, and first valve, and a circuit comprising said second transformer; condition responsive switch, second switch and second valve.

'7. The combination with a. heating system comprising first and second electrically operable valves controlling the supply of fuel to a main burner and a pilot burner for igniting the main burner, of a control system for said valves, comprising, in combination, a pilot switch, a main control switch, a third switch moved to open position by said first valve when opened, a first transformer having sufilcient capacity to operate a only said first valve, a second transformer having sufficient capacity to operate only'said second valve, a circuit comprising said first transformer. first valve, pilot switch and main 'control switch and a circuit comprising said second transformer, second valve, pilot switch, main control switch and third switch.

8. A heating system of the class described, comprising in combination, first and second electrically operated gas valves for controlling the fiow of gas to a burner for heating a space, a space temperature responsive thermostatic element, four control switches sequentially closed thereby upon temperature fall, first and second holding switches respectively closed by said first and second gas valves when energized, a valve operated switch moved to open position by said trolled by said third control switch and second holding switch in series. v

9. In combination, means responsive to the value of a condition, three switches sequentially closed thereby upon continued change of said condition in one direction, first and second elec trically operable valves, a fourth switch which is opened by said first valve upon opening thereof, a fifth switch which is closed by said second valve upon opening thereof, an energizing circuit for the first valvecontrolled by said first switch, a first energizing circuit for the second valve controlled by the first switch and fourth switch in series, a second energizing circuit for the second valve controlled by the third switch, and a holding circuit for the second valve controlled by the second switch and fifth switch in series.

10. In a valve controlling system, in combination, a first valve including motor means in control thereof, a second valve including entirely able to close said second valve upon opening of a said first valve.

11; In a valve controlling system, in combina-, tion, a first valve including motor means in con trol thereof, a second valve including entirely separate and independent motor means in control thereof, a control member in control of the motor means of both valves operable to cause simultaneous opening of both of said valves, control means actuated, by said first valve in control of the motor means of the second valve operable to close said second valve upon opening of said first valve, and a second control member in controlof said second valve motor operable to open the second valve independently of the condition of said control means. 1

12 In an electrical valve controlling system, in combination, a first valve including electric motor means in control thereof, a second valve including a separate electric motor means in control thereof, a first control switch, circuit connections for the motor means of both valves controlled by said first control switch operable to open both valves upon closure of the first control switch, and switching means operated by said first valve which causes closure of the secondvalve upon opening movement of said first valve.

13. In an electrical valve controlling system, in

combination, a first valve including electric motor means in control thereof, a second valve including a separate electric motor means in control thereof, a first control switch, circuit connection for the motor means of both valves controlled by said first control switch operable to' open both valves upon closure of the first control switch,

switching means operated by said first valve which causes closure, of the second valve upon opening movement of said first valve, a second control switch, and circuit connections controlled thereby for the motor means of said second valve to cause opening thereof upon closure of the second control switch.

' 14. In an electrical valve controlling system, in

said first control switch operable to open both valves upon closure of the first control switch, switching means operated by said first valve which causes closure of the second valve upon opening movement of said first valve, 2. second control switch, circuit connections controlled thereby for the motor means of said first valve to cause opening thereof upon closure of the second control switch, and a movable member responsive to a condition which sequentially closes said first and second control switches.

15. In a valve controlling system, in combina tion, a first valve comprising means to bias the same to closed position and an electric motor to open the same and hold it open against its bias when energized, a second separate valve including separate biasing means which biases the same. to closed position and a separate electric motor to open the same and maintain it open against its bias when energized, a first control switch, energizing circuits for each of the motors of said' valves completed by closure of said first control switch, a second control switch in the circuit for the motor ofthe second valve, connections between the first valve and second control switch to openthe second control switch upon opening movement of said first valve, a third cofitrol switch, and a; separate energizing circuit for the motor of said second valve controlled by said third control switch independently of said second concompleted by closure of said first control switch,

a second control switch in the circuit for the motor of the second valve, connections between the first. valve and second control switch to open the second control switch upon opening movement of said first valve, a third control switch, a separate energizing circuit for the motor of said second valve controlled by said third control switch independently" of 'said secondcontrol switch, and a single condition responsive member to sequentially close said first and third control switches. V

' JOHN P. KRIECHBAUM.

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