US2041559A - Control mechanism - Google Patents

Description

May 19, 1936. A. A. MARKS CONTROL MECHANISM Filed Aug. 25, 1928 a sheets-sheet 1 Coumon.

A. A. MARKS 2,041,559

CONTROL MECHANISM Filed Aug. 25, 1923 3 Sheets-Sheet 2 I 48 39 Q I I52! x I l 5 204 l /I I E HZ v INV EN TOR Alexander A; Mar/f3 May 19, 1936; A. A. MARKS ,559

CONTROL MECHANISM Filed Aug. 23, 1928 3 Sheets-Sheet 3 Men/Z01? Patented May 19, 1936 NITED STATES PATENT OFFICE 9 Claims.

My invention relates to flow control and the provision of means rendering flow dependent upon the concurrence of independent conditions acting through suitable mechanisms to conjoint- 1y control the valve mechanism regulating a port or passage through which flow may occur. It pertains primarily to the 110w of fluid fuel and the provision of apparatus whereby the flow of the fuel can be started and stopped, either man- 10 ually or automatically by remote control mechanism, during the maintenance of conditions adjacent to the intended place of consumption of the fuel insuring combustion thereof, but which will render the automatic control mechanism inoperative should the conditions insuring combustion cease to prevail.

While my improvements are of general application, they are particularly designed for controlling the flow of gaseous or liquid fuel to a burner ignited'by a pilot. Preferably the flow is controlled at the point of discharge to a burner chamber by a valve or cap sealing the end of the supply conduit and normally operable by mechanism controlled by a thermostat, pressurestat or other remote control device, but which mechanism is rendered inoperative upon the extinguishment of the pilot for igniting the burner.

If desired, however, the parts may be so arranged as to permit flow of fuel while either the pilot or burner is ignited instead of rendering the remote control mechanism inoperative by the extinguishment of the pilot or of both pilot and burner, it may be rendered inoperative upon attainment of a desired maximum pressure or 5 temperature in a boiler heated by the burner, or

the like.

Ordinarily the flow of gas to a gas burner is controlled by a valve set back some distance from the discharge end of the supply conduit and leaving between the valve and the end of the conduit a pocket or chamber in which uncon-' sumed gas tends to accumulate and cause explosions or back-firing. In the preferred embodiment of my improvements, this objectionable feature is eliminated by providing a valve plug which caps or enters the discharge end of the conduit.

The valve or plug is preferably mounted upon a carrier consisting of a fulcrumed lever pressed in one direction by a spring or weight. The carrier may be latched against the action of the spring or weight by a catch having a latching position and an unlatching and non-latching position. An actuator, such as a lever operable by a, thermostat, pressurestat or the like, is provided with means, such as a dog, for moving the valve carrier into latching position and with an arm for moving the catch into unlatching position, so that the position of the valve may be automatically controlled by remote control ap- 5 paratus.

When, however, further flow under such control is undesirable, as, for instance, when conditions at the place of fuel consumption are such that fuel supplied will not be consumed, the 10 catch is movable to non-latching position by mechanism influenced by such conditions. Such conditions arise in connection with a fuel burner, for example, upon the extinguishment of the pilot or of both the burner and the pilot, when 15 further flow of fuel is undesirable even though the remote control mechanism is so actuated as to normally open and latch the valve. The catch is, therefore, normally subjected to the influence of means, such as a spring or weight, 20 tending to move it to non-latching position, but the action of such means is normally counterbalanced or overcome by a heat responsive mechanism so positioned as to be heated and expanded by combustion at the pilot or at the burner or both.

In my preferred construction, the catch or latching device consists of a spring lever fulcrumed on a bearing movable by a heat expansive member forming or connected with the pilot 30 tube. The expansion of the member positions the bearing so that the latching lever is held in a latching position in the path of the nose of a fulcrumed lever having the valve connected therewith. 35

Trip mechanism. operable to release the latching lever from the valve lever may also be provided or the closing of the valve by the automatic remote control mechanism may be otherwise effected. In one embodiment of my im- 40 provements, the valve lever and the trip mechanism are operated by movements in opposite directions of a lever controlled by a thermostat or the like and having thereon a pivoted dog for rocking the valve lever and an arm for rocking 5 the trip mechanism. In other embodiments of my invention, the thermostatically controlled lever acts on the valve through members positioned by the latching and unlatching of the valve controlling lever. 50

When the heat expansive member contracts, the latching lever is moved to a non-latching position out of the path of the valve controlling lever, which either returns the valve to closed position directly or so positions the valve operating members as to prevent the actuation of the valve therethrough.

The characteristic features and advantages of my improvements will more fully appear from the following description and the accompanying drawings in illustration of embodiments of my improvements applied to a gas burner of the Bunsen type.

In the drawings, Fig. 1 is a part sectional side elevation. of a preferred embodiment of my invention: connected with a gas burner. and pilot tube therefor, the burner and pilot tube being shown in fragmentary form; Fig. 1A is a view of the mechanism shown in Fig. 1 with the parts in the position occupied when the valve is latched open; Fig, 2 is a transverse sectional view onathe line 22 of Fig. 1. Fig. 2a. is a diagrammatic side elevation of the structure as shown in Fig. 1, with parts omitted. Fig. 3 is a fragmentary sectional view of the end of a pilot tube having a supplementary thermostatic" device therein-7 Fig. 4 is a similar view showing a modified formof supplementarythermostatic device; Fig. 5 is a detached plan view of an adjustable stop for the latching lever; Fig. 6 is a fragmentary view of slightly modified mechanism through which the valve controlling lever transmits motion to the valve; Fig; 7 is an end viewof the mechanism shown in. Fig. 6; Fig; 8 is a fragmentary view of a further modified mechanism through which the valve is operated; and Fig. 9 is a fragmentary View of further modified mechanism through which the valve is operated.

As illustrated; in Figs. 1 to 5 inclusive of the drawings; a fluid fuel supply conduit I has its end mounted in a hollow hub 2 of a disk 3 containing apertures controlled by a revoluble shutter 4 mounted on the hub 2, as in a usual Bunsen burner:

A boss' 5 is screwed intothe projection 2' of the hub 2' on the opposite side of the disk 3 from the pipe'l and contains a passage communicating with the bore ofthe hub 2 and pipe I-. The outer end of thepassage through the boss 5 is flared to form a; seat 6- forreceiving aconoidal valve or cap 1 pivotally connected with the angularly bent arm 8 of the" bell crank lever 8. Thevalve has'a slight play longitudinally of its pivot and its movement about its pivot is limited by the engagement of the rear face of the valve with the edge of the lever B. The lever 8 is pinned to the shaft 9' journalled in bearings It of the projection 2".

A spring ll, seated in the recess l2 and engaging the stud l3 on the upper arm 8" of the bell crank l'ever 8, normally presses the arm 8 outward soas to seat" the valve 7 in the valve seat 6, the slight axial and rotary movement of the valve on its pivot permitting it to be accurately seated to form a tight joint.

To unseat the valve 1, the lever 8' is rocked by means of a pin l4 thereon which is' engaged and lifted by the tapered nose of a bell crank lever I5 fixed to a pivot l6 journalled'in' the bell crank lever H; the movement of the lever it in one direction being limited by the engagement of its pin V5 with a projection ll." of the lever H. The lever IT is fixed to a shaft I8 journalled in the hub or bracket 2' and in a bearing is on the flange 20 of the disk 3.. A lever. 21 is fixed to the the outer end of the shaft l8 and has a weight 22" depending from the outer end thereof to normally rock the lever and shaft in. one direction.

The arm of'the bellcrank l1 opposite the proj'ection' H is provided with a tapered end 23 disposed between the legs 24 of a yoke having a body 25 journalled on the stud 26 threaded into the bracket 2, and an arm 2'! is bent upward from such body 25 and has a finger or trigger 28 at right angles thereto and in the plane of but above the body 25 and offset from the yoke 2d.

The arm 8" has a beveled top forming a tapered nose 29 adapted, when the valve '1 is opened, to occupy a position to the left of, and to be engaged by, the complementary nose 3% formed by the end of a lever 3! when such lever is in a substantially vertical or latching position. The lever 3| is fulcrumed between a pair of knife edges 32, 32' seated in notches in the upper part of the lever 3|. The knife edges 32 are formed on a block'33' adjustable, by a lock bolt 3 in the bracket 35 projecting from the member 452.

The upper end of the lever 3i and the mechanisms connected therewith are housed within a hood 36 fixed to the member 32 by screws 3?.

The knife edge 32" is offset vertically from the knife edge 32 therebelow'and is formed on a block 33 fixed to the rod 39. A spring 50 is coiled around the stud M fi-xed in the housing 32 and presses against the upper end of the lever 3! so as to normally press it away from the housing 42.

The member 42 is bolted to a housing 43 mounted on an extension of the flange 20, and a diaphragm- 44 is engaged between the members 62 and 53 soas to seal one end of the chamber 45 in the housing 43. The rod 39 passes through an aperture inthe diaphragm M and nuts 36 and washers 41 seal the joint between the diaphragm and the rod.

A pilot tube Z8 formed of metal readily expansible by heat is seated in the end of the housing 4 3' opposite the diaphragm 54 and has at the outer end thereof a plug 49 in which is anchored the end of the brass rod 39, which is maintained at a substantially constant temperature by the fluid fuel flowing through the pilot tube and hence varies very little in length as a result of expansion or contraction.

Gas is-admitted to the chamber 65 through a suitable'port 50 connected through a by-pass with the main supply pipe I to supply gas which is burned at the apertures 5| of the pilot tube to. form a pilot light which heats and expands the pilot tube so as to increase the length thereof and exert a pull on the rod 39.

If it is desired to secure greater movement of the rod 39 than results from the expansion and contraction of the tube 48, a bi-metallic thermostatic loop 49a (Fig. 3) or a bi-metallic thermostatic dished disk 4'91) (Fig. 4) may be connected to the rod and tube. The heat of the pilot light burning adjacent to' the member 3911 or 591) will cause such members to move toward the outer end of the tube and exert a pull on the rod.

When the pilot light is extinguished, the members 39, 49a or 4% cool and contract and exert a thrust on the rod 39 and move it and the lever 35 toward the left (Fig. 1) to its unlatching or non-latching position thereby effecting a positioning of the lever 3i so that the valve l may be opened through distant control mechanism connected with a chain 5?. The maximum movements of the lever 3! to the right may be limited by the slotted plate 29a adjustably fixed to the flange" 25 by the screw 26b so that an excessive pull upon the rod 39 cannot cause the spring ii to move the lever-3i beyond its latching position.

The holes 5| are preferably positioned between the bottom of the tube and the median horizontal plane thereof to secure freedom from detritus and avoid burning the tube while projecting the flame in the desired direction.

An indicator plate 52, visible through the open ing 53 in the hood 36 is bolted to a lever 54 fulcrumed on a pin 55 fixed to the bracket 35. The lever 54 has its bifurcated end 54 engaged by a pin 56 on the lever 8. The movement of the lever 8 acts through the mechanism described to move the plate 52 and indicate by the exposure of suitable inscriptions thereon Whether the gas is turned on or off.

The pilot tube projects over a burner A supplied with gas through the port 6 and having usual burner apertures 2a, see Fig. 2a. The pilot tube and burner are in such proximity that the gas flowing through the burner apertures is ignited initially by the pilot light maintained at the apertures 5| which latter keeps the tube 48 or the members 49a, 49b expanded. The burner and tube may be placed in such proximity that while either the burner or the pilot tube is lighted the tube 48 or members 48a, 49b is expanded by the heat thereof but this is ordinarily not necessary.

The pull on the rod 39 acts to move the knife edge 32 and permit the spring 40 to move the nose 38 of the lever 3| toward the right so as to position such nose 38 in the path of the nose 29 and latch the lever 8 against the action of the spring I I when the valve has been moved to open position.

My control mechanism is particularly adapted for use where it is desired to control the flow of fuel by means of a thermostat, pressurestat, or other heat regulator or remote control device 221'. Such remote control device acts through a tension member 51 on the lever 2 I. So long as the pilot is ignited, the nose 38 is normally positioned ready to latch the nose 29 and hold the valve 1 open when the lever 2| is lifted by the remote control device through the tension member 51 to rock the lever 8 through the parts I 8, I5 and I4. As the parts 29 and 38 latch, the nose of the arm I5 passes under the pin I 4. If, however, the pilot is extinguished, the nose 29 is not engaged by the nose 38 because the rod 39 has thrust the lever 3| from its latching position.

When sufficient fuel has been consumed to give a temperature or pressure above that at which the thermostat or the like is set, the remote control device releases the member 51 so that the weight 22 acts to depress the lever 2| which acts through the shaft I8, arm 23, and yoke 24 to rock the tripper 28 against the lever 3|. This moves the nose 39 to the left against the action of the spring 48 and out of the path of the nose 29, and the spring II thereupon rocks the lever B and seats the valve 1 in the seat 6, the arm I5 rocking on its pivot so as to assume its initial position.

When the temperature or pressure again falls, the remote control device again acts through the tension member 51 to lift the lever 2| and rock the arm 23. The movement of the arm 23 disengages the tripper 28 from the lever 3| and permits the spring 48 to rock the lever 3| and restore the nose 38 to its latching position. Continued upward movement of the lever 2| causes the arm I5 to rock the lever B through the pin I4 and again latch the valve in the open position, as previously described.

When, however, the pilot is extinguished, the cooling and contraction of the tube 48 or the members 49a or 481) shifts the knife edge 32 to the left, which rocks the lever 3| so that the nose 38 is moved to the left out of latching position. Consequently when the lever 2| is elevated by the remote control mechanism, the nose I5 lifts and passes under the pin I4 but the valve immediately recloses because the nose 38 is not in position to latch the nose 29. Hence there can be no flow of fuel when there is no flame available to ignite it and the most dangerous feature of automatically operated fluid fuel burners is thus obviated. The flow through the pilot is ordinarily too small to be dangerous or important, but if desired the pilot feed line can also be closed by a valve controlled by the movement of the rod 39.

When it is desired to light the burner after the burner and pilot have both been extinguished, the pilot should be lighted so as to expand the rod 48 or a member 49a, 49b. The burner can be directly lighted only by manually holding the lever 2| in such position as will cause the nose I5 to hold the pin I4 in elevated position and unseat the stopper 1. When the heat of the pilot or burner expands the tube 48 or a member 49a, 4%, the nose 38 is moved thereby into normal latching position and the nose 29 may be latched behind it.

As illustrated in Figs. 6 and 7, it is sometimes desirable to eliminate the downwardly bent integral arm 8 of the lever 8 and to connect the lever B with the valve I by intermediate mechanism comprising bent levers 68 having fixed thereto a pintle 6| on which the apertured boss of the valve 1 is journalled. The levers 88 have their upper ends journalled upon pins 62 fixed in brackets 63 secured to the member 2. A pin 64 fixed in the levers passes through an elongated slot 8a in the outer end of the lever 8.

It will be understood that the movements of the lever arm 8 are transmitted through the pin 64 to the levers 68 to seat or unseat the valve 1, as previously described. By the interposition of levers 68 between the lever 8 and the valve 1 greater clearance and more accurate seating of the valve may be secured.

Where a series of valves are disposed in alignment, the levers 8 may be mounted in suitably spaced relation upon a single rod 9 extending through all the mechanisms or the several rods 9 may be coupled together and operated as one, so L that all the valves are controlled by a single lever 3| and its connected parts. In such tandem arrangements, a single control mechanism may be utilized for the actuation of a plurality of individual valves.

My improved mechanism is also applicable to the control of types of valves other than that described. For instance, where it is desired to control a supply main to effect the simultaneous operation of a number of burners or to control the supply to the pilot as well as the burner, my improvements may be connected with valve mecha nisms such as shown in Figs. 8 and 9 to supple-' ment or supplant the action of the valve 1.

As illustrated in Fig. 8, the action of a valve such as shown at I in Fig. 1 may be supplemented by having its lever B fixed to a shaft 9 to which is fixed an arm 65 containing an elongated slot 66 for the engagement of a pin 61 set in a lever 68 which is fulcrumed on a yoke bracket 89 of the valve casing 18. An arm 2|, operable from remote control mechanism through a tension member 51', is pivotally connected by a pintle 68' with the end of the lever 88 remote from the pin 61.

The vertically reciprocable stem 1|, for operating a normally closed valve in the casing 19, has fixed thereto a yoke or slotted member 12 which straddles the levers 88 and 2|;

When the lever 8 is unlatched from the lever 3 I, by the mechanism and in the manner described in connection. with. Fig. 1 it is passed. by the. spring I I: soas to turn the shaft 9 on its axis and thereby turn the arm 65 to the position shown in full lines.

1y, when the lever 2.1 is. operated. by the tension member 51', it does not contact with the top I2 of the yoke. 12' and. the valve. is inoperable by the remote control mechanism.

When, however, the nose; 29. is latched. behind the nose 36, by the. mechanism and in the manner described in connection with Fig. l the shaft 9 is turned by the lever 81 so that the arm 65 is moved to the position shown in dotted lines, thereby tilting the lever' 68' and elevating the fulcrum formed by the. pintle. 68. Hence when the lever 2| is operated by remote controlmechanism through the tension member 51', the yoke I2 of the valve is engaged and operated by the lever 2!.

The maximum movement of the lever 2| may be limited by its engagementwith. the curved top 69 of the member 69..

As illustrated in Fig. 9, the action of a valve such as shown at I in Fig. 1 may be supplemented by having its lever 8 fixed to a shaft 9" to which is fixed an arm I5. The arm I5 is connected by an adjustable link I6 withan. arm 11 pivoted on the stem I8 adapted for operating a normally closed valve in the casing I9. A bracket on the valve casing has fulcrumed thereon a lever 2! operable from remote control mechanism through a tension member 51", the maximum movement of the lever 2|" being limited by a slotted bracket 8 I" on the valve casing.

When the lever: B is. unlatched from the lever 3i, by the mechanism. and in the manner described in connectionwith Fig. 1, it is turned by the spring II on its axis and. turns the shaft 9 and arm I5 so as to act through the link I6 and elevate the arm. 71 out of the path of the lever 2|". Consequently the movement of. the lever 21" by the remote control mechanism is ineffective to operate the valve. When, however, the lever 8 is latched. behind the lever 3|, by the mechanism. and in the manner described in connection with Fig. 1, the arm I5 is turned by the shaft 9 to the dotted. line position and moves the arm 7! into position to be engaged by the movement of the arm 2|" to operate the valve when the arm ZI" is; moved by the remote control mechanism.

Having described my invention, I claim:

1. The combination with a burner, a pilot adjacent to said burner and a fuel-control valve normally biased toward closed position, of remote control mechanism controlling from a remote point the position of said valve and moving it toward open position, and mechanism operable by the combustion of fuel at said pilot for controlling said valve: independently of the action of said remote control mechanism, said second named mechanism reestablishing the effectiveness of the control of said remote control mechanism over said valve upon the mere ignition of fuel at said pilot.

2. The combination with a burner, a pilot adjacent to said burner, means forming a passage discharging fuel to said burner, and a valve adapted to seal the extreme end of said passage and movable toward and; away from sealing position, of remote control mechanism for moving said valve into and out of said sealing position, and mechanism operable by the combustion. of

This. rocks the lever 68 on. its fulcrum to: the full line'position. Consequentfuel at said. pilot for controlling said valve in dependently of the action of said remote control mechanism, said second named mechanism rendering said remote control inefiective upon the extinguishment of a flame at said pilot and. re.- establishing the effectiveness of said remote con:- trol mechanism. upon the ignition of. a flame at: said pilot.

3. The combination with a burner, a pilot, valve mechanism controlling the flow of fuel to said burner, a remote control for said valvev mechanism, and means for rendering inoperative the remote control when the pilot is extinguished and again rendered operative by the mere ignition of the pilot. and without any adjustment or operation of the mechanisms and including an actuator operable by said remote control, lever mechanism through which said actuator rocks said valve mechanism upon movement of the actuator in an upward direction, latching mechanism holding in place the lifted valve mechanism notwithstanding any return of the actuator to a lower position, means by whichsaid actuator releases said latching mechanism upon the movement of said actuator to a lower position, and thermostatic mechanism controlled by said pilot for releasing said latching mechanism independently of said actuator.

4. The combination with a latch, means for shifting said latch and comprising a pilot tube with a thermostatic member housed therein, a lever controlled by said latch, valve operating means actuated by said lever, and a valve operable by said means.

5. The combination with a burner, a pilot adjacent to said burner, a fuel control valve, and means normally biasing said valve toward closedposition, of latching means for holding said valve in open position against the action of said biasing means, control mechanism operable from a remote position and including means for positively opening said valve against the action of said biasing means, said mechanism also including means for tripping said latching means, and mechanism operable by the combustion of fuel at said pilot for controlling said latching means independently of the action of said remote control mechanism and rendering said latching means ineffective upon the cessation of combustion at said pilot, said second named mechanism reestablishing the potential efiectiveness of said latching means upon the mere ignition of fuel at. said pilot.

6. In combination a support, a detent on the support, means for moving the detent between operative and inoperative positions, a valve biased toward closed position, a. latch for the detent movable with the valve, andmeans for moving the valve and its latch against the valve bias and releasing them at a position for latching cooperation of the latch with the detent to hold the valve open in said operative position of the detent.

7. In combination, a support, a detent on the support movable between operative and inopera-- tive positions, a thermal device, a valve controlling said device and biased toward closed position, a latch for the detent movable with the valve, means for moving the valve and its latch against the valve bias and releasing them at a position for latching cooperation of the latch with the detent to hold the valve open in said operative position of the detent, and means re- III sponsive to thermal. conditions of said device for 7 moving the detent between operative and inoperative positions.

8. In combination, in a burner including main and pilot-gas-jet elements, a support, a detent on the support movable between operative and inoperative positions, a valve controlling the main burner element and biased toward closed position, a latch for the detent movable with the valve, means for moving the valve and its latch against the valve bias and releasing them at a position for latching cooperation of the latch with the detent to hold the valve open in said operative position of the detent, and thermalresponsive means controlled by one of said gasjet elements for moving the detent between operative and inoperative positions.

9. The combination with a burner, a pilot, valve mechanism controlling the flow of fuel to said burner for cooperation with a remote control for said valve mechanism, and means for rendering inoperative the remote control when the pilot is extinguished and again rendered operative by the mere ignition of the pilot and without any adjustment or operation of the) mechanisms and including an actuator operable by said remote control, lever mechanism through which said actuator rocks said valve mechanism upon movement of the actuator in an upward direction, latching mechanism holding in place the lifted valve mechanism notwithstanding any return of the actuator to a lower position, means by which said actuator releases said latching mechanism uopn the movement of said actuator to a lower position, and thermostatic mechanism controlled by said pilot for releasing said latching mechanism independently of said actuator.

ALEXANDER A. MARKS.

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