US1854519A - Controlling apparatus for steam boilers and the like - Google Patents

Description

April 19, 1932. El N. McDoNELLE-r AL 1,854,519

CONTROLLIN-G'APPARATUS FOR STEM BOILERS AND THE LIKE-` Filed May 8, 1926 3 Sheets-Sheet l H r ,L k n X vl I` li: LQ W?? W f n w {Il} April 19, 1932- E. N. McDoNNr-:LL E-r AL '1,854,519

CONTROLLING APPARATUS FOR STEAM BOILERS AND THE LIKE Filed May 8, 1926 3 Sheets-Sheet 2 ms: @f @acadien/mwa y/MMW- April 19, 1932.

E: N. McpoNNELL ET AL CONTOLLING APPARATUS FOR STEAM BOILERS AND THE LIKE Filed May 8 1926 3 Sheets-Sheet 5 Patented Apr. 19, 1932 UNITED Y,STATES PATENT OFFICE EVERETT N. MCDONNELL, LEO` B. MILLER, AND OSCAR F. CARLSON, OF CHICAGO, ILLINOIS, ASSIGNORS, .BY MESNE ASSIGNMENTS, T MINNEAPOLIS-HONEYWELL REGULATOR COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF DELA- WARE CONTROLLING ARPARATUS FOR STEAM BOILERS AND THE LIKE Application tiled May 8, 1926. Serial No. 107,649.

' more particularly to means for shutting off the supply of liquid fuel when the water in the boiler falls below the desired level, or when the pressure rises above a predetermined point.

Boilers, such, `for example, as are used in the heating of houses are quite commonly taken care of by those who do not fully understand the operation and the proper regulation thereof, or who do not have the necessary time for inspection at proper intervals. As a result, it frequently occurs that the water is permitted to drop below the required level, resulting in damage to the equipment, or the steam pressure is permitted to become unnecessarily high, thus causing the safety valve to release, with an accompanying waste of heat and fuel. This is particularly true of oil burning boilers where occasional attention only is required, and as a result it often happensl that the water supply is'entirely forgotten for considerable periods of time.

The general object of our invention therefore is to provide improved apparatus for protecting boilers, and the like, against p'ossible damage due to lack of sufiicient water, and to prevent unnecessary waste of fuel through excessive steam pressure.

Anotherobject is to provide a single apparatus for performing both of these functions by the use of an electric, switch arranged to open the circuit of the motor which su 'plies the oil 'to` the burner, said switch being actuated by means responsive both'to variation in water 'level and variation in steam pressure.

Another object is to provide duplex equipment of this character which may be readilymounted on the boiler by removing the water gage and connecting said equipment by means of nipples or the like screwed into the tapped Iholes in the boiler to which said gage was previously connected. l

A further object is to provide mechanism comprising a motor control switch, and means 60 automatically actuated under predetermined conditions of steam, vacuum or Water lan oil heater and motor showing one embodiment of our invention in relation thereto.

Fig. 2 is a vertical section thereof on line 2 2, Fig. 1.

Fig. 3 is a front elevation of the switch in closed position, together with its operating mechanism.

Fig. 4 is an end elevation thereof.

Fig. 5 is a view similar to Fig. 3, with a portion of the mechanism broken away.

Fig. 6 is a view similar to Fig. 5 showing the parts in switch opening position.

Fig. 7 is an elevation of a sliding weight.

Fig. 8 is a section thereof showing the method of mounting the same.

Fig. 9 is a-broken detail view showing a modified form of a portion of the apparatus.

Fig. 10 is a top plan view of the Iiexible diaphragm, shown in Fig. 9, and

. Fig. 11 is an elevation of a modified form of mercury switch.

The boiler 10 may be assumed to represent any standard type of steam, vapor, hot water or other heater using liquid fuel, such as low grades of oil, the latter beingsupplied to the so-called oil burnerby am0t0r12,the source of supply and connections -not being shown.

The control apparatus forming the subject matter of the present invention is housed in a' suitable casing, preferably in the form of a casting 13, supported on and connected to the boiler by means of nipples 14, 14, in a manner similar to that employed in `connecting the usual water gage to the tapped openings i'n the boiler. Said nipples are screwedinto these same openings, which were provided originallyfor the water gage, the glass y gage being removed to permit the substitution of said control apparatus. In case said tapped openings inthe boiler do not aline properly with the corresponding openings in the casing 13, the upper connection can be changed by making use of the opening in which the plug 15 is screwed (see Fig. 1) or the bottom opening in which the drain-cock 16 is screwed may also be used, provided that The easing 13 is provided with a water` gage 17, as shown in Fig. 1, by means of which the level of the water in the boiler can be observed in the same manner as though saidcasing were not interposed between said gage and the boiler. This gage glass 17 may be the identical glass tube removed from the boiler in making the installation.

As shown in Fig. 2, the casing 13 is enlarged at its lower portion forming a Hoat chamber 18. Secured to said casing is a second casing 19, in the lower portion of which is a stud 2O to which is pivoted, at 21, 'the arm 22 of oat 23. The arm 22 has a lateral extension at its.pivoted end provided with a cam surface 24, against which bears a roller 25 carried by lever 26, which in turn is pivoted to the'depending arm 27 of a plate 28. The latter is secured to the upper apertured wall of casing 19; A plunger 29 is connected to `the lever 26. passes vertically through said aperture and bears against a stud 30 in the upper end of the expansive bellows 31, which latter are secured to the plate 28 by any approved means.

It will be apparent that Water from the boiler will iow through the lower nipple 14 .of the casing 13 i-ntothe chamber 18, causing the float 23,to.rise`to the position shown in Fig. 2, which action of the float by means of the cam 24 permits the plunger 29 to move downwardly to lowermost position. It will also be seen that the top of the fiexible bellows 31 will tend to lift as the pressure of the steam in the boiler increases. y

Should the water level in the boiler drop sufliciently to cause the float to move downwardly in the chamber 18, cam 24 will raise roller 25 and move plunger 29 upwardly, ex-

panding the bellows.' This movement of the plunger 29 and subsequent expansion ofjbellows 31 will cause a link 32 to4 move upwardly, such movement being transmitted to the operating mechanism to open the switch, thereby causing the motor 12 to stop. The

link 321s guided at its lower end by a flange ceive a correspondingly notched upper extension 36. The two notched portions may thus be fitted together, as shown in Fig. 2, without fastening them. The upper end of extension 36 has a pivotal connection with a U-shaped member 37, the latter turning about a pivot 38 fixed in a supporting plate 39, which latter is held by screws 40 which seat within lugs 41 (Fig. 2), formed integrally with the casing 35.

The rear flange of the U-shaped member 37 has an upper extension 42 which has pivotal connection, at 43, with a lever 44, said lever carrying lan adjustable weight 45 threaded thereon at one end and a roller 46 on the opposite side of the pivotal support. The roller 46 is engaged by one or the other of the inclined cam faces 47 and 48 of the pivoted switch carrying member 49, pivotedon the stud 50. A link 51 connects the channel member 37 with member 49, as shown in Fig. 5. The stud 50 and spacing screws 52 and 53 hold a front plate 54 in s aced relation ,to the rear plate 39 (see Fig. 4

Member 49 carries a pair of resilient arms 55 by means of which a mercury tube 56 is supported, a rubber or other protecting member 57 being disposed between the glass and the arms 55. The tube 56is provided with a pair of contacts 58, 58, and a quantity of mercury 59. When the switch is tilted to the position'shown in Fig. 3, the mercury gravitates to the right end of the tube and bridges the contacts, thereby closing the motor cirposition, the mercury gravitates to the other end of the tube, .thereby opening the motor circuit and stopping the motor. This movement of the switch will be effected by the upward movement of 'link 32, previously described. .1

It will be apparent that the upward movement of link 32 will cause channel member 37, to move in a counter-clockwise direction, as viewed in Fig. 5. Link 51, which is slotted at its upper end, will transmit this movement .to the cam member 49. The roller 46 will follow the inclined surface 48 until it passes the center point when the weight 45 will cause a quick snapover of the member 49, thereby quickly opening the circuit without permitting substantial arcing.

Weight 60 is arranged to slide back and forth on the front flange 61 ofthe channel 37 and is held in place Vby a screw 62 provided with a knurled head 63, said screw passing through a slot 64 in said flange.l The weight may thus be adjusted to vary the re- .sistance which plunger 3 2 offers to movement of the bellows 31. Withthis arrangement the mechanism can be set so that the motor will be stopped when the pressure in the boiler reaches any predetermined value; for example, seven pounds, and by adjusting this weight and the weight 45, the range of operation may be made anything desired within working limits. For example, the circuit may ope-n at pressure of six pounds and close at five pounds, or the range may be four pounds to six pounds, or any other desired range.

By sliding weight 60 to the left or to the opposite side of theV center line of the pivot 38 the device is adapted to operate where a vacuum system is employed.

The casing 35 has an opening in the front wall thereof which is normally closed by a small door 65 by means of which access to the switch mechanism can readily be had.

In Figs. 9 and 10, we have shown another' embodiment of our invention in which a corrugated diaphragm 66 is shown which functions similarly to the flexible bellows 31, previously described.

Vith the construction described, it will be seen that no stufling-box is required or packing which might eventually leak or require renewal. The pressure adjustment can be readily changed by opening the door to the switch box and changing the lposition of the counter-weight.- To change the differential range over which the switchwill operate, it is necessary only to change the position of the small counter-weightA on vits threaded stem.

In installing the device the lower nipple 14 determines the proper position of the parts with reference to the desired water level so that no care or skill is required in making the installation. lVhere floatdevices have been used heretofore in connection with boilers, it has been necessary to run special piping from a point in the -top of the boiler to a point near the bottom, necessitating great care in positioning' the device some where near the desired water level, after which considerable adjustment was required to insure operationv at the desired level.

Although 'the invention in the present equipment is used to open the motor circuit, it is obvious that it may be used in connection with a stop signal located either'at the base` ment or any remote part of the building to indicate either low water or high steam pressure. Furthermore, it will be understood that although the apparatus is described as being particularly adapted to be substituted for a water gage on a boiler already in use, it may of course be installed as part of the initial equipment., Various 4other changes may be made in the equipment described whichillustrates only one embodiment of the invention.

We claim as our invention:

l. A device of the class described comprising a housing having openings communicating with a boiler above and below the normal water level thereof, means in said housing responsive to variations in the water level, means in said housing responsive .to variations in pressure, and a single switch controlled by either of said means independently for opening and closing an electric circuit.

2. Apparatus of the class described comprising a casing having a fiuid compartment, a fioat therein, a flexible member responsive to fluid pressure in said compartment operatively associated with and movable by said float, a second compartment in said casing sealed by said flexible member against fluid 'admission from said fluid compartment, a switch, and means in said second compartment connected to and actuatable by the movement of said flexible member for effecting a quick snapover of said switch.

3. In a device of the class described, an expansible bellows having a closed top and an open bottom, a reciprocable plunger arranged axially in said bellows and bearing against the end thereof, a float arranged to move said plunger in a direction to expand said bellows when said float lowers, said bellows being subject to fluid pressure through said open` bottom, whereby it may expand out of contact with said plunger, and means actuated by the movement of the end of said bellows for controlling a circuit.

4. Apparatus of the class described comprising a casing having a ioat chamber, a switch chamber, a switch therein, a flexible member responsive to fluid pressure in said chamber between said chambers, afloat in said float chamber responsive to the level of the water in said chamber, and means operable by said loat for transmitting motion through said flexible member to said switch for moving the same to on or off position.

5. Apparatus of the class described comprising a casing having a float chamber, a flexible member responsive to fluid pressure in said chamberclosing an opening in said casing, an` electric switch .exterior of said chamber, anda float in s aid chamber for controlling said switch through said flexible member.

6. Apparatus of the class described comprising a easing having afloat chamber, 'a float in said chamber responsive to the level of the water therein, a flexible member responsive to fluid pressure in said chamber closing an opening in said casing, and a switch exterior of said chamber and controlled by said float through said flexible member, said switch being movable to olf position by the expansion of said flexible member independently of-Asaid float.

7. Apparatus of the class described comprising a casing, a float actuated member pivoted therein, a switch exterior of said casing, said casing having an opening, an expansible member closing said opening, a switch operating member responsive to fluid pressure in saidcasing secured to said expansible inember for actuating said switch upon the expansion and contraction of said member, and a member in said casing movable by said pivoted float member for actuating said switch operating member, whereby said switch is controlled by said float.

8. A device ofthe character described, comprising a float chamber, a float in said cham- `bei* and responsive to variation of liquid level prising a float chamber, a oat in said cham'- ber and responsive to variation-of liquid level therein, a controller, means for transmitting motion from said float to said controller to cause actuation of the controller, a diaphragm element sealing said last-named means to the chamber and responsive to fluid pressure in said chamberto actuate said controller, and means for controlling the operation of .said diaphragm to cause actuation of said controller when the fluid pressure in said chainber exerts a determined force on said diaphragm. v

v 10. A device' of the character described, comprising afloatchamber, a float in said chamber and responsive to variation of liquid leveltherein, a controller, means for trans- 'to said thrust element and sealed to said mitting motion from said float to said con-` troller to `cause actuation of the controller,

`a cylindrical metallic bellows sealing said last-named means to the chamber and responsive to fluid pressure in said chamber to actuate said controller, and means for controlling the operation of said bellows to cause actuation of said controller when the fluid pressure in said chamber exerts a determined force on said bellows. l

11. A device of the character described, comprising a float chamber, a float in said chamber and responsiveto variation of liquid level therein, a controller, a thrustelement operatively engaging said controller, means for transmitting motion from said float to said thrust element to actuate said controller` a fluid pressure-responsive device connected chamber, said device responding to fluid pressure in said chamber to cause said element to actuate said controller, and means for'controlling the operation of said fluid pressureresponsive means to cause actuation of said controller when the fluid'pressure in said chamber exerts a determined force.

l2. A device of the character described,

comprising a float chamber, a float in said chamber and responsive to variation of liquid leveltherein, a controller, a thrust element operatively engaging said controller, means for transmitting motion from said float to said thrust element to actuate said controller, and a cylindrical metallic bellows device connected to said element and sealed to said chamber, said bellows responding to fluid pressure in said chamber to cause said element to actuate said controller. 4

13. A device of the character described, comprising a float chamber, a float in said chamber and responsive to variation of liquid level therein, a controller, a thrust member for transmitting motion from said float to said controller' to cause actuation of the controller, fluid pressure-responsive means acting on said thrust member and responsive to pressure in said chamber to actuate said controller, said fluid pressure-responsive means including a diaphragm member sealing the thrust member to the float chamber, and

means for controlling the operation of said diaphragm to causel actuation of said controller when the fluid pressure in said chamber'exerts a determined force on said diaphragm.

14. A rdevice of the character described, comprising a float chamber, a float in said chamber and responsive to variation of liquid level therein, a controller, a thrust member for transmitting motion from said float tosaid controller to cause actuation of the controller, and fluid pressure-responsive means acting on said thrust member and responsive to fluid pressure in said chamber to actuate said controller, said fluid pressure-responsive means including a corrugated eXpansible-collapsible bellows sealing the thrust member to the float chamber. 4

15. A device of the character described, comprising a float chamber, a float in said chamber and responsive to variation of liquid level therein, a controller, a rockable element rocked by said float, thrust means for transmitting motion from said'rockable element to said controller, means for sealing said float chamber, said sealing means being subject to fluid pressure within said chamberand movable by said fluid pressure to actuate said thrust means to operate said controller, and means for controlling the operation of said sealing means to cause actuation of said controller when the fluid pressure in said chamber exerts a determined force on said sealing means. Y

16. A device of the characten described. comprising a float chamber, a float in said chamber and responsive to variation of liquid level therein, a controller, means for transmitting motion from said float to said controller to actuate the controller, fluid pressure-responsivemeans sealing said chamber and acting through said transmitting means to actuate the controller, and means `for controlling the operation of said fluid pressureresponsive means to cause actuation of said A controller when the fluid pressuref in said 1 chamber exerts a determined force.

17. A device of the character described, comprising afloat chamber, a loat in said chamber and responsive to variation of liquid level therein, a controller, means for translevel therein, a controller, means for transmitting motion from said float to said con-y troller to cause actuation of the controller,` iluid pressure-responsive means sealing said last-named means to the chambenand responsive to fluid pressure in said chamber to actuate said controller,- means resisting actuation of said'controller by said pressure-responsive means, and means for setting the resistance of said resisting means whereby said pressure-responsive means responds to a determined pressure condition in said chamber.

19. A device of the character described,

the combination of a chamber, a lever pivoted therein, a float carried by said lever, .means for admitting pressure to said chamber, a

pivotally mounted switch, a cam on said' switch, an arm carryin a roll for rocking said cam and means, including a bellows adapted\to be expanded by pressure in said chamber, operatively connected with said cam roll arm, said float lever being operatively connected with said bellows for oscillating the upper end thereof forcausing said cam roll to rock said cam.

In testimony whereof we have subscribed our names. v

EVERETT N. MCDONNELL. LEO B. MILLER. OSCAR F. CARLSON.

comprising a float chamber having a side,

opening, a substantially Ly-shaped hollow {itting engaging and in communication with said chamber through said sidev opening, flexible means sealing said hollow tting, a plunger reciprocally mounted in said fitting and adapted to operate *a circuit control means, afloat in said float chamber and means in said iitting and extending through said side opening l and connecting said iioat and said plunger` whereby movement of said float will move said plunger.

20. In a device of the character described, the combination of a chamber, a lever pivoted therein, a iloat carried by said lever, means for admitting pressure to said chamber, a pivotally mounted switch, a cam `on said switch, an arm carrying a roll for rocking said cam an means, including a bellows adapted to be expanded by pressure in said.

chamber, operatively connected with said V cam roll arm, said floatlever also being operatively connected with said cam roll arm. 21. In a device of the character described,

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