US1891081A - delaney - Google Patents

Description

Dec. 13, 1932. w DELANEY 1,891,081

I NNNNNNNNNNNNNNNNNNNNN 0L Filed Oct. 16, 1950 10 Sheets-Sheet 1 |NVENTOR 77km KFeZane BY-i ATTORN EY Dec. 13, 1932. DELANEY 1,891,081

' INTEGRATED FURNACE CONTROL I Filed Oct. 16, 1930 10 Sheets-Sheet 3 INVENTOR L3- 771077 05 WJeZane ATTORNEY Dec. 13, 1932. 11. w. DELANEY INTEGRATED FURNACE CONTROL Filed Oct. 16. 1930 10 Sheets-Sheet 4' INVENTOR 207206 WITNESS W? ATTORNEY Dec. 13, 1932. w DELANEY 1,891,081

INTEGRATED FURNACE CONTROL Filed Oct. 16, 1930 10 Sheets-Sheet 5 1 INVENTOR 31 4 mamas fi fjezezay ATTOR N EY Dec. 13, 1932. w DELANEY 1,891,081

INTEGRATED FURNACE CONTROL Filed Oct. 16. 1950 10 Sheets-Sheet 6 M my f J H INVENTOR 73%072205 Wflfhfi] 0 BY WITNESS ATTORNEY Dec. 13, 1932. T. w. DELANEY.

INTEGRATED FURNACE CONTROL Filed Oct. 16. 1930 10 Sheets-Shet 7 WITNESS W Dec. 13, 1932. w, DELANEY 1,891,081

INTEGRATED FURNACE CONTROL Filed Oct. 16, 1930 10 Sheets-Sheet 8 o MOTOR ATTORN EY WITNESS Dec. 13, 1932. I T w A EY INTEGRATED FURNACE CONTROL Filed Oct. 16. 1930 10 Sheets-Sheet 10 15s Jig WITNESS 1% /E 262 V I Owes aw WW BY ATTORNEY Patented Dec. 13, 1932 NT OFFICE THOIMAS VJ. DELANEY, OF ST. PAUL, MINNESOTA INTEGRATED FURNACE CQNTROL Application filed October 16, 1930.

This invention relates to'furnace controllers and particularly to controllers for fur naces of steam boilers and consists in the novel combination of elements and arrange- 5 ment of parts as will be hereinafter fully described and claimed.

It is a purpose of the present invention to provide primary controlling means responsive to changes in load demand which will cooperate with a secondary controlling means in order to produce an integrated relative position of the parts of a series of furnace auxiliaries such as fans, dampers and fuel feeders. It is a further object to provide a furnace control which will be responsive to changes in the operating conditions of the furnace as well as to changes in the loaddemand there on.

It is a further object to provide a controller provided with means for manually adjusting any one of a series of controls independently of the remainder of the series.

It is a further object of the invention to provide means for indicating the relative position of the controlling parts.

Further important objects will become apparent during the course of the following detailed description taken in conjunction with the accompanying drawings, in which Figure 1 is a perspective View of a boiler furnace showing my improved controller in operative relation thereto;

Fig. 2 is a front elevation of the primary and secondary control integrating mechanism with part of the casing thereof broken away;

Figure 3 is a section of the primary control switch and operating motor taken along the line 3-3 of Figure 2,

Figure 4 is an end elevation partly in section of the secondary control switch and operating motor.

Figure 5 is a central vertical cross section of the secondary control switch;

Fig. 6 is a top plan view thereof;

Fig. 7 is across section on the line 7-7 of Fig. 5;

Fig. 8 is a perspective view of the reciprocating plunger of the secondary control;

Fig. 9 is a top plan view of an interrupting mechanism and circuit controlling means Serial No. 489,221.

for the primary and secondary operating moors;

Fig. 10 is a cross section on line 10l0 of Fig. 9 with the base shown in cross-section;

Fig. 11 is a perspective view of the switch contacts removed from the switch of Fig. 9;

Fig. 12 is a side elevation partly in section of the operating means for the furnace damper;

Fig. 13 is a side elevation of the operating means for the fan motor controller and fan delivery damper;

Fig. 14 is a detail view of the auxiliary operating motors shown in Figs. 12 and 13;

Fig. 15 is a top plan View thereof;

Fig. 16 is an end elevation of the parts shown in Fig. 14;

Fig. 17 is a partial cross sectional View on line 1717 of Fig. 15;

Fig. 18 is a horizontal sectional View taken on line 1818 of Fig. 14; and

Fig. 19 is a perspective view of a part of the magnetic switch.

Referring now particularly to the drawings in which like numerals refer to like parts 7 throughout the same, 20 indicates a boiler furnace equipped with an under feed stoker 21, and a fan 22 operated by a motor 23. The fan being adapted to deliver air under pressure through pipe 2% to a point beneath the fire pot of the furnace. The pipe 24L is provided with a suitable damper 25,. The furnace is further provided with the usual flue damper, the operating crank 26 thereof being shown.

A steam line 27 leading from the boiler carries the load demand from the boiler. A primary control switch 28 is provided to progressively close electric circuits as the flow of steam through line 27 increases and open them when the flow through said line decreases. This primary control switch may be of the type disclosed in my co-pending application Serial Number 399,379, filed October 12, 1927. e

The secondary control switch 29, responsive to operating conditions within the furnace, is also provided, the specific construction of which will be hereinafter more fully described.

The gas pressure on the furnace side of the flue damper is communicated to the secondary control switch through pipe and the over fire pressure in the furnace is communicated to said switch. through pipe 31.

The contact points 32 of the primary control are connected by wires 33 to the contact studs 34 of the primary rotary control switch. The contact studs of the primary rotary control switch are carried by a circular ring 36 which is substantially mounted on a standard 37. Contact fingers 38 and 38a are carried on the face of a gear wheel 39 which is keyed to a shaft 40. The contact fingers 38 are so arranged as to make contact with various contact studs 34 as the gear wheel is rotated. An electric motor 41 drives a worm gear 42 through shaft 43. The worm 42 meshes with gear 44 which drives gear through shaft 6. The gear 45 meshes with gear wheel 39 thereby driving the same and causing the contact fingers 38 to travel in a circular path.

A series of controller disks 47 48 and 49 are provided. Although three of such disks are shown, any desired number could be provided, depending on the number of furnace auxiliaries to be controlled. These disks are rotatably mounted upon shaft 40. The periphery of these disks is provided with gear teeth which mesh with gears 50, 51 and 52 respectively. Gears 51 and 52 are mounted upon and rotate with a shaft- 53 which is driven through motor 54, shaft worm 56 and worm gear 57. The gear is an idler gear and is driven by gear 58 which is mounted upon and rotates with shaft 53. It will thus be seen that by driving the disk 47 through the idler gear 50, this disk is reversely rotated with relation to the disks 48 and 49.

Rotatably mounted upon shaft 40 are a series of worm gear segments 59. Projecting from the face of each worm gear segment 59 is a pin 63 upon which is mounted an idler gear 64 which meshes with a gear 65 which in turn is keyed to the shaft 40. Rotatably mounted upon shaft- 40 directly adjacent each gear 65 is a gear 66 which also meshes with the idler gear 64. Distributor arms 67 are secured to each of the gears 66 so as to rotate therewith. The device is operated automatically due to changing conditions, and rotation of the shaft 40 together with its attached gears 65 will cause the rotation of the gears 66 and thus the arms 67 through the medium of idler gears 64.

Referring to Figs. 2 and 4 it will be seen that a standard 68 is provided which provides a bearing for one end of the shaft 40 and also supports the segment of a circular plate 69 which is provided with contact studs 7 O. Rotatably mounted upon the shaft 40 adjacent the plate 69 is a secondary controller arm 71 provided with contacts 72 and 73 at its free end which are adapted to make contact with the studs on the plate 69. The arm 71 is mounted on a sleeve 74 which is secured to a disk 49 so that the arm 71 will move when the disk 49 is driven by the motor 54.

The contact studs 7 O on the plate 69 are carried by means of wires 75 to terminals 76 projecting from the walls of the secondary control switch 29.

The secondary control switch 29 comprises a receptacle 77 which is partially filled with oil. Suspended within the receptacle 77 is a bell member 7 8 which is secured to the tube 79 which extends into the bell an appreciable distance from the top wall thereof. Also suspended within the receptacle 77 and within the space enclosed by the bell member 78 is a second bell member 80 which is provided with a centrally located vertical tube 81 closed at the bottom as at 82 and being secured to rod 83 at this point. A circular recess 84 is thus formed around the rod 83 in which the lower end of the tube 79 has free vertical movement. By filling the recess 84 with oil a frictionless seal is thus obtained between the tube 7 9 and the ball member 78. It will be noted that the rod 83 extends through the bore of the tube 7 9 and that they both extend through an opening in the cover 85 of the receptacle 77.

Mounted upon the cover 85 is a cup 86 which is provided with a well centrally thereof through which the tube 79 and rod 83 are adapted to pass. The rod 83 has a cross head 87 mounted upon the upper end thereof. This cross head 87 is provided with depending plungers 88 which project downwardly into bores formed in a cylindrical piston element 89 which is disposed in the annular recess 90 formed by the outer wall and central well of the cup 86.

The upper end of the tube 79 has oppositely disposed slots 91 extending downwardly from the end thereof so as to allow free vertical movement of the head 87 on the end of the rod 83. The tube 79 also has cross head members 92 secured at the upper end thereof which support depending plungers 93. The plungers 93 project downwardly into bores formed in the piston 89.

The receptacle 77 has a circular wall 94 extending upwardly from the bottom thereof and surrounding the bell member 80. This wall 94 provides a well in which the bell member 80 can reciprocate and also forms an annular compartment within the receptacle 77 into which the sides of the hell 7 8 depend.

The space under the bell 78 is placed in communication with the furnace above the fire thereof by means of pipe 31 and passage 95 which is formed with the wall 94. The space under the bell member 80 is placed in communication with the flue on the furnace side of the outlet damper by means of pipe 30 and passage 96 extending through the bottom of recess 77. By partially filling the cup 86 with mercury and the receptacle 77 with oil the bell members with their attached tube and rod, cross heads, anddepending plung ers are suspended in these liquids by reason of displacing portions thereof equal to their own weight. '1 hus it'will be seen that as the gas pressures in the furnace change, the bells, together with the plungers will be caused to move either up or down to vary the height of mercury in the cup 86.

A lever 97 which is provided with a forked end 98 is pivotally connected with a. bracket 99-carried at one side of the cup 86 at the upper end thereof. Curved levers 100 are pivotally mounted at the top end of an upstanding pivotal link member 101 which is free to rock towards or away from the cup 86. The free ends of the levers 100 are pivotally connected to the forked portions 98 of the lever 97 so that upon movement of the lever 97 levers 100 will also be actuated. Curved fingers 102 are also mounted on the bracket 99 and the link 101 and secured to the levers 100 and the forked ends 98 of the lever 97. The free ends of these. fingers rest on'the top of piston element 89 which is adapted to float in the mercury contained in the cup 86. When the lever 97 is lowered and the free ends of the fingers 102 are in engagement with the piston element 89, said piston will be depressed in view of the fact that the yoke 98 will be lowered as will be the curved levers 100. Since the pair of curved fingers which are attached to the levers 100 are moved downwardly simultaneously with the curved fingers that are attached to the ends of the yoke 98, the upper end of the link 101will be moved slightly outwardly from the cup 86. The rise or fall of the piston element 89 with in the receptacle 86 will change the height of the mercury in said receptacle.

The lever 97 has a cable 103 secured to the free end thereof and the cable in turn has its opposite end secured to a cam member 104 which is mounted on the shaft 40. Therefore i it will be seen that when the primary control- 1 position of the piston 89 therein.

A magnetic switch is provided for controlling the circuit to each of the motors 41 and and 54. As the switch for each motor is the same for the other, only one switch will be described in detail.

Referring to Figs. 9, 10 and 11, motor shaft has a brake wheel 105 mounted thereon which is encircled by a contracting brake band 106. The brake band 106 is provided with depending fingers 107 which straddle the squared end 108 of rock shaft 109. The shaft 109 is supported in upstanding bearings carried by a base 110. The base 110 is also provided with upstanding walls 111 and 112, the wall111 carries contacts studs 111a which are connected to the motor 54 and the wall 112 carries a similar set of studs 112a. hen the circuit is completed through studs 1110, the motor is driven in a clock-wise direction and when the circuit is completed through studs 112a the motor is driven in a reverse direction. The rock shaft 109 carries on suitable lever arms 113 and 114, armatures 115 and 116 of magnets 117 and 118 respectively, the magnets being mounted on supporting standards 117a and 118m carried by the base 110. The arm 113 is rotatablymounted on the rock shaft 109 but when its magnet 117 is energized the.

top edge of said lever contacts with the projection 119 on the collar 120 which is secured to the rock shaft thereby disposing the parts in the position shown in Fig. 10. The counter weight on the opposite end of the arm 113 balances the weight of the armature 115 to maintain said armature and the magnet 117 in operative relation when the magnet is deenergized. The arm 114 of armature 116 is rigidly secured to the rock shaft 109 so that when the magnet 118 is energized and the armature 116 raised, the rock shaft will be rotated so as to cause the contact fingers 121 to contact with the set of contacts carried by the wall 111. hen the magnet 118 is de-energized the weight of the arm 114 and armature 115 returns the contact arms 121 to neutral position. If the magnet 117 is then de-energized the weight of arm 114 would further rock the shaft 109 and move the contact fingers 121 into contact with the studs 112a, thereby reversing the motor circuit.

In order to prevent overadjustment in either direction in response to changed conditions in the operation of the boiler an interrupting mechanism is provided for both the primary and secondary control drive motors 41 and 54. As this interrupting mechanism is the same for each motor it will suffice to describe the same only in connection with motor 54 and its associated switch mechanism.

Mounted on the end of rock shaft 109 is a cross bar or lever 122 which is arranged so that it will be in a horizontal position when the contact fingers 121 are in neutral position shown in Fig. 10. Levers 123 and 124 are pivoted at 125 to a bifurcated bracket 126 which extends forwardly from the standard 127 the bifurcated bracket 126 being disposed on either side of the worm gear wheel 57. Each of the levers 123 and 124 is provided with a rearwardly extending trip arm 128 and 129 respectively. The trip arms 128 and 129 are so arranged that each is adapted to engage an opposite end of the'cross bar 122 when the forward end of its lever is raised.

The worm gear wheel 57 is provided with a series of pins 130 which project from the side thereof and are adapted to engage pawls 131 and 132 which are carried by the levers 123 and 124 respectively. The pawl 131 is arranged so that the lever 123 will be raised when one of the pins 130 engages the pawl 131 upon a counter-clock-wise rotation of the gear 57. The pawl 132 is so arranged that the lever 124 will be raised when the gear is turned in a clock-wise direction. The standard 127 is provided on either side with a latch trigger 133 which is equipped with a weight 134 to normally urge the latch to pivot in a forward direction. When the parts are moved from the position shown in Fig. 4 the latch 133 is prevented from contact with the cross bar 122 by reason of its upper end being forced to retracted position by the rear end of the trip arm 128. However, when the rock shaft 109 is given a partial rotation to close the circuit to the motor 54 and the gear 57 is thereby rotated the cross bar 122 will be raised above the horizontal position as will be readily understood. Rotation of the gear 57 will then cause one of the pins 130 to engage the pawl of one of the levers 123 and 124 thereby raising the same. Assuming that the gear was rotating in a counter clock-wise direction the end of the cross bar 122 adjacent the trip arm 128 would be in raised position so that when the lever 123 was raised the trip arm 128 would be depressed thereby bringing the cross bar 122 back to the horizontal position and breaking the circuit to the motor.

At the same time the arm 128 will engage the latch 133 which would pivot forwardly and release the bar 122, thereby locking the same in horizontal position until the lever 123 returns to normal position.

The forward end of the levers 123 and 124 are provided with weights 134 to normally urge them to the position shown in Fig. 4 and are also provided with depending pitmans 135 which are attached to pistons 136 which are disposed in cylinders 137. The pistons are hollow and are filled with oil which also partially fills the cylinders 137. Each pitman 135 extends through the top wall of its respective piston and is slidable therethrough. The lower end of each pitman 135 is formed as a plug valve which is adapted to engage the valve seat formed at the inner end of an enlarged port 138 in the bottom wall of the piston. An enlargement 139 formed on the pitman just above the lower end thereof allows said end to open and close the port 138 upon up and down movement of the levers 123 and 124 but prevents the disconnection of the pitman from its respective piston. A second port 140 formed in the bottom wall of each piston is adapted to be partially closed by an adjustable metering pin 141. It will thus be seen that when the lever 123, for example, is raised by a pin 130,

the pitman 135 with its piston will also be raised when the oil contained within the piston and the cylinder will flow freely through the port 138 into the cylinder below the piston. When the pin 130 rides off of the pawl 131 and the weight 134 tends to return the lever to normal position the lower end of the pitman 135 will close the enlarged port 138 and the oil within the cylinder will be forced to flow slowly through the metered opening 140 before the parts can return to normal position. By adjusting the metering pin 141 the length of the time of operation of the circuit to the motor 54 can readily be changed to suit the operating conditions being encountered.

Referring now to Fig. 3 and assuming that the parts in the position shown are adjusted to meet the load demand on steam line 27, the circuit will be completed from the power line through primary control switch 28, to the contact stud which is in contact with finger 38, through the magnet 117, and thus back to the line. This completed circuit would dispose the contact lingers 121 in neutral position. An increase on steam line 27 would cause the primary control switch 28 to close the circuit from the line through the contact stud engaged by finger 38a, through the magnet 118 and thus back to the line. This circuit would cause the contact fingers 121 to engage the studs 111a thereby completing the circuit to the motor 41 and causing the same to drive the gear 44 in a clock-wise direction which would drive the gear wheel 35 and its contact fingers 38 and 38a in a clock-wise direction. This will cause the contact finger 38a to ride off of the energized contact and thereby break the circuit to the magnet 118, which would also allow the circuit to the motor to be broken. This rotation of the gear wheel 39 would rotate the shaft 40 which through gears 65, (34 and 66 would cause a change in the position of the controller arms 67 which control the circuits to the operating motors of the furnace auxiliaries which will present ly be described.

A decrease in demand on the steam line 27 would result in the primary control switch breaking the circuit to the stud in contact with the finger 38 and thus to the magnet 117 whereupon the reverse circuitto the motor 41 would be completed and the gear wheel 35 would be driven in a counter-clock-wise direction until the finger 38 came in contact with a circuit completing contact stud which would complete the circuit through the magnet 117 thereby breaking the circuit to the motor 41.

Referring now to Figs. 4 and 5, under nor mal operating conditions the cup 86 would be filled with mercury to a point midway between the upper and lower most contact terminals 76 and the circuit would be completed fromthe. line through the stud in contact with finger 72 and through this finger to the magnet 117, maintaining the contact fingers 121 in the neutral position shown in Fig. 10. Operation of the primary control mechanism due to increase in load would rotate the shaft and thus the cam 104 in a clock-wise clirection which would cause the cable 103 to lower the lever arm 97, depressing the piston member 89 and raising the height of the mercury in cup 86 thereby completing the circuit to the contact 7 3 and magnet 118 thereby closing the circuit to the motor and causing the same to operate in a clock-wise direction which Wlll result 1n drivlng the disk 49 and arm 71 in a counter-clock-wise direction to cause the finger 7 8 to ride off of the contact stud onto a dead stud to break the circuit to the magnet 118 and allow the magnetic switch to open the motor circuit.

The contour of the cam 104 is designed so that the compensating piston 89 raises or lowers with load change to compensate for the opposite movement of the plu'ngers 89 and 93 when the difierential pressures acting on bells 7 8 and are those which have been determined as giving the most efficient combustion to the load being carried. Should the differential pressure vary from those desired the mercury will be raised or lowered making or breaking contact with higher or lower contact points 7 6 and causing the secondary controller to make necessary corrections in air and gas flow and fuel feed by causing rotation in the proper direction of the controller disks 47, 48 and 49. It should be noted that by varying the proportions and weight of the bells 78 and 80 and their respective plungers 93 and'88, a wide range of operative conditions may be dealt with. The larger the proportion of weight of each bell and its associated plungers that is supported by the buoyant action of the bell itself, the less it will be affected by movement of the other bell and plungers.

Referring now to Fig. 12 the controller disks 48 with its associated collector arm 67 is shown as controlling the circuit to the motor for operating the flue damper. As a similar mechanism is used to control the stoker, a description of the same in relation to the damper will suffice for both.

The collector arm 67 is provided with a contact member 142 which is placed in circuit with a source of electric energy by wire 143. When the arm 67 is moved due to operation of the primary control mechanism and rotation of shaft 40 or due to manual operation of. the primary control disk 48, or moved byreason of the operation of "the secondary control mechanism, the contact member 142 makes a contact with one of the contact studs 144 carried by the control disk. The circuit is thus established through contact 142, stud 144, one of the wires 145, to one of the contacts 146 carried by the stationary segment 147 which is supported by the L-shaped plate 148 which also supports the magnetic switch and motor which controls the furnace auX- iliary, which in this case is the damper. A shaft 149 passes through the side of L-shaped plate 148 and provides a pivot for the mounting of the gear segment 150 which carries for wardly projecting spaced contact members 151 and 152 which are insulated from said gear segment. The gear segment is rocked about its pivot by means of a motor 153, worm 154, worm gear 155 and pinion 156 which is mounted upon the end of worm gear shaft 157 and which meshes with the seg ment 150, all of which is more clearly shown in Figs. 14 and 15. Armatures 158 and 159, of magnets 160 and 161 are secured at either side of rock shaft 162 on a rocker arm 163 which is keyed to said rock shaft, the magnets being mounted in operative relation to the armatures by supports160a. and 161a, respectively. The rock shaft 162 is provided with three depending contact fingers 164, one

of which carries an upwardly'extending lug 165 which is disposed between the depending ends of the spring brake band 166 which encircles the brake wheel 167 carried by the motor shaft 168.

The horizontal section of the L-shaped plate 148 carries a member 169 which forms a support for the oppositely disposed sets of contact points 170 and 171. When the circuit is completed through magnet 161 to attract armature 159 the circuit will be completed through contact points 171 to cause a clock-wise rotation of the motor 153, the lug 165 at the same time spreading the brake band to allow the rotation of the motor shaft. Likewise when the circuit is completed through magnet 160 to attract armature 158 the reversing circuit to the motor is completed and the brake band released in the magnet 161 which will result in a clockwise rotation of the segment 150 which will continue until the energized stud 146 lies between the contact members 151 and 152, whereupon the magnet will be de-energized. If contact member 142 energizes the stud 144 which is connected to one of the studs 146 which is in contact with the contact member 152, the magnet 160 will be energized, thereby completing the reversing circuit to the motor and l causing a counter-clockwise rotation of the motor and the gear segment which will continue until the energized stud 146 lies between the contact members 151 and 152.

The damper operating lever 172 is secured to the extended hub of gear segment 150 by a set screw 173 fitted in one of a number of holes drilled in the flanges of the lever 172 and gear segment 150 whereby the lever 172 may be adjusted to any one of a number of positions relative to the gear segment 150. Suitable linkage is provided between the lever 172 and the damper or stoker, or other auxiliary as the case may be.

The control for the fan motor 23 and for the damper 25 located in the delivery duct of the fan 22 is shown in Fig. 13. As the magnetic switches, motor and associated gear mechanism used with these auxiliaries are the same as that used with the damper and stoker the same will not be again described in detail but a description of the controlling circuits thereto will suffice.

The contact finger 174, carried by the 0011- trol arm 67, makes contact with one each of two circularlyarranged series of contacts 17 5 and 176. Contacts 175 are connected together in a series of groups, each group being connected to a contact on the segment 175a of the circuit controller of the motor 177 which controls the rheostat 178 of the fan motor 23.

The contacts 176 lead to the magnets which control the circuits to the motor 179 which operates the damper 25 in the delivery duct of the fa-n 24. It will be noted that a number of wires 180 leading from the contact studs 176 are connected with wires leading from a stud three points lower. The purpose of this cross connection of the studs will now be explained.

If all of the contact studs 175 and 176 were consecutively and individually connected to contact studs in the same manner that the contact studs 144 of the flue damper are connected, progressive movement of the contact member 174 would cause a speeding up of the fan motor with a corresponding opening of the damper 25. However, this is not desirable as a finer adjustment is often found necessary. Therefore, by connecting the contacts 175 into groups, the speed of the fan motor will be increased or decreased only when the contact member 174 travels from one group to another. The contacts 176 not being grouped together, the damper 25 would be caused to gradually open or close as the contact member 174 moves from one end to the other of a single group of contacts 175. By cross connecting the leads from the con tact studs 17 6 to one, three or more points lower or higher in the series, the damper 25 will be caused to first close as the speed of the fan motor is increased by reason of the contact member 174 passing from one group or" contacts 175 to another. Then as the contact member 174 moves over this particular group,

the fan motor 23 running at a constant speed, the damper 25 would be gradually opened thereby adjusting the flow of air by means of the damper alone until it is entirely open. Then when the contact member 174 moves to the next group of contacts 175 the speed of the fan motor 23 would be increased and the damper 25 would be partially closed and the above cycle would be repeated. If the contact member 174 were moved in the opposite direction the reverse of the above would be true, that is, each time the speed of the fan motor was decreased the damper would becaused to completely open, then upon fur ther travel of the contact member 174 the damper would gradually close, the speed of the motor 23 remaining constant.

It may be desirable at times to render either the primary or secondary control mechanisms, or both, inoperative so that the furnace auxiliaries may be manually adjust ed. In order to provide for this I have devised a means for disconnecting the gears 44 and 57 from their respective shafts. As shown in Fig. 9 this means comprises a hand wheel 205 which is provided with a toothed collar 206 which is slidably keyed to its respective shaft 46 or 53. The worm gears 44 and 57 are rotatably mounted upon their respective shafts 46 and 53 and each provided with teeth which are adapted to engage with the teeth on the collar 206 when it is desired to operate the device automatically. By pulling out on either of the wheels 205 the teeth on the respective collar will be disengaged from the teeth on the worm gear and the particular controller will be rendered in operative.

The toothed collars 206 and the teeth on the worm gears form in effect toothed clutches which when disengaged will permit the various furnace auxiliaries to be entirely manually operated. It will be noted that either of the clutches may be disengaged without affecting the other so that if desirable the primary control mechanism may be operated automatically and the secondary control mechanism rendered inoperative or vice versa.

A suitable mechanism is provided for indicating the positions of the various controller arms, disks, etc., which are contained within the housing 181.

Cable 182 is wound around sleeve 7 4 of the secondary control arm 72 and is trained around sheave 183 which is carried by the front wall 184 of the housing 181. The cable is then trained upwardly and over sheave 185, thence downwardly, over sheave 186 and its other end wound on the hub 187 of the primary distributor arm 67 in an opposite direction to the end which is wound on the hub 74. The sheave is rotatably mounted in stirrup 188 which is suspended by means of cabl 189 from a sheave 190 which is suplOJ ported above the sheave 185 by means of bracket 191. The loose end of the cable 189 is provided with a weight 192. The stirrup 188 is provided with a depending arm 193 which is in turn provided with a pointer 194: which projects through a vertical slot and cooperates with scale markers in the face of the wall 18%. The cable 182 is provided with a pointer 195 between sheaves 183 and 185 which pointer projects through a vertical slot formed in the wall 18% and which cooperates with scale markers 196. The cable 182 is also provided between sheaves 185 and 186 with a second pointer 19? which also projects through a slot in the wall 184:. The pointer 195 indicates the position of the secondary controller arm 71 and the pointer 197 inclicates the position of the primary controller arm 67. The pointer 19% registers the integrated position of both of the latter mentioned arms and thus indicates the relative positions of distributor arm 67 and its respective disk 29.

Cables 198, one for each manually controlled segment 59 have their lower ends wound upon the hub of such segment and pass under sheaves 199 and over sheave 200. The upper free end of each of these cables after it passes over the sheave 200 is provided with a weight. The front wall 18% is provided with elongated openings 201 through which a pointer 201a mounted upon each of the cables 198 indicates the position of the worm gear segments 59 on a suitable scale.

Cable 202 has its lower end wound about a pulley 203 secured to the end of primary control shaft l0 and also has its other end trained over a pulley 200 and provided with a counter-weight. This cable is also provided with a pointer 203 which projects through an elongated slot 20a in the wall 184% and which indicates the position of the gear wheel 39 of the primary control switch.

Assuming that the furnace auxiliaries are in a position to meet the load demanded from the boiler, an increase in the load would result in the operation of the primary control mechanism which would operate the shaft a0 and thus controller arm 67 to effect an adjustment of the various furnace auxiliaries to meet the changed condition. At the same time through the medium of cable 103 and lever 9?, the piston 89 of the secondary control switch would be depressed. This depression of piston 89 would result in a change in the height of mercury in cup 86 and would thus cause an operation of the secondary controller to compensate for the changed con ditions. The secondary controller will then function to operate the furnace auxiliaries to meet the requiren'ient placed on the boiler. In order to prevent an overadjustment of either the primary or secondary controll r, the interrupting mechanism including arms 71 has been provided which will cause these switches to operate in a step by step manner instead of continuously.

Although, in the embodiment shown, the control system is applied to a furnace equipped with an under feed stolrer, variable speed forced draft fan, a damper in the duct between the fan and stoker, and a flue damper for controlling the induced draft, it should be understood that other forms of fuel and feeder equipment may be controlled without departing from the spirit of the invention within the scope of the appended claims.

I claim:

1. In a device of the character described, a primary controller shaft, controller arms driven therefrom, a secondary controller shaft, and controller disks driven therefrom. said arms and disks cooperating to control auxiliary operating circuits.

2. In a device of the character described, a primary control mechanism, a secondary control switch including a receptacle containing a column of mercury, pressure responsive means for regulating the height of mercury in said receptacle and means for adjusting the height of mercury in said receptacle upon operation of said primary control mechanism.

3. A furnace control switch comprising a liquid holding receptacle, a bell member having its skirt immersed in said liquid, a mercury holding contact cup, plungers reciprocable therein for varying the height of mercury, means for establishing communication between the underside of said bell and the furnace, means for connecting said plunger-s to said bell for reciprocation therewith, whereby to vary the height of mercury upon changes of pressure within the furnace.

a In combination with a furnace having a boiler and a steam main; primary control mechanism, a primary switch and motor drive for said primary control mechanism responsive to variations in said steam main, secondary control mechanism, a secondary switch and motor drive for said secondary control mechanism responsive to variations in pressure in said furnace, manual adjusting means for said primary control mechanism, a series of auxiliary circuit controllers whose position is the integrated result of the primary and secondary control and manual adjusting means.

5. In a furnace control mechanism, a differential pressure switch including two bells, one having overfire furnace gas pressure above and gas outlet pressure below the same, the other bell having atmospheric pressure above and overfire furnace gas pressure below the same, said bells having the lower edge of their shirts sealed by immersion in oil, a mercury switch, and displacement plungers associated with each of said bells and immersed in the mercury of said mercury switch whereby to vary the height of mercury therein upon movement of said bells due to variations in furnace gas pressures.

6. In a furnace control mechanism including a horizontal shaft, movable controller contact arms driven therefrom, a second horizontal shaft and controller contact disks driven therefrom, said arms and disks cooperating to establish circuits for controlling furnace auxiliaries.

7. In combination with a boiler furnace having a steam main, a primary control mechanism including movable contact arms, means responsive to changes in pressure in said steam main for actuating said primary control mechanism, a secondary control mechanism including movable contact disks, means responsive to changes in furnace operating conditions for actuating said secondary control mechanism, said arms and disks cooperating to establish electric circuits for regulating said furnace.

8. I11 combination with a boiler furnace, a mercury switch including a receptacle containing mercury and adapted to successively establish and break electric circuits as the level of the mercury rises and falls, reciprocable displacement plungers immersed in said mercury, means responsive to pressures Within said furnace for adjusting the position of said plungers and means controlled by said switch for operating furnace regulators.

9. In combination with a boiler furnace having a steam main and the usual furnace auxiliaries; a circuit controlling means i11- cluding movable contact arms and movable contact disks cooperating therewith, load responsive means for moving said arms to complete preliminary auxiliary adjusting circuits, means responsive to furnace operating conditions for moving said disks to complete readjusting circuits to said auxiliaries.

10. In a furnace control mechanism ineluding a horizontal shaft, controller contact arms driven therefrom, a second horizontal shaft, controller contact disks driven therefrom, and means for manually adjusting said contact arms, said arms and disks cooperating to establish circuits for controlling furnace auxiliaries.

11. In combination with a boiler furnace having a steam main, a primary control mechanism including movable contact arms, means responsive to changes in pressure in said steam main for actuating said primary control mechanism, manual means for individually adjusting each of said contact arms, a secondary control mechanism including movable contact disks, means responsive to changes in furnace operating conditions for actuating said secondary control mechanism, said arms and disks cooperating to establish electric circuits for regulating said furnace.

12. In combination with a boiler furnace having a steam main, a primary control mechanism including movable contact arms, means responsive to changes in pressure in said steam main for actuating said prima y control mechanism, manual means for individually adjusting each of said contact arms, a secondary control mechanism including movable contact disks, means responsive to changes in furnace operating conditions for actuating said secondary control mechanism, said arms and disks cooperating to establish electric circuits for regulating said furnace, and means for periodically interrupting the operation of said primary and secondary control mechanisms.

13. In combination with a boiler furnace having a steam main and the usual furnace auxiliaries, operating means for said auxiliaries, a circuit controlling means including movable contact arms and movable contact disks cooperating therewith, load responsive means for moving said arms to complete preliminary adjusting circuits to said auxiliary operating means, means responsive to furnace operating conditions for moving said disks to complete re-adjusting circuits to said auxiliary operating means, means for manually and individually adj usting' each of aid contact arms, and means for periodically interrupting the operation of said means for moving said arms and said disks.

14. In combination with a furnace having the usual auxiliaries, an electrical control for one of said furnace auxiliaries comprising a stationary plate having a plurality of spaced contact points carried thereby, a motor for regulating said furnace auxiliary, a pair of spaced contact members movable over said points in synchronism with the regulation of said auxiliary, each of said contact members being adapted to control a separate reversing circuit to said motor, and means responsive to furnace operating conditions for successively energizing said contact points.

15. In combination with a furnace having the usual auxiliaries, an electrical control for one of said furnace auxiliaries comprising a stationary plate having a plurality of spaced contact points carried thereby, a motor for regulating said furnace auxiliary, a pair of spaced contact members movable over said points in synchronism with the regulation of said auxiliary. each of said contact members being adapt-ed to control a separate reversing circuit to said motor, a primary control mechanism responsive to ariations in load demand on said furnace. a secondary control mechanism responsive to variations in furnace operating conditions, and includ ing an integrating switch having relatively movable cooperating contact members for establishing circuits for successively energizing said contact points.

16. In combination with a boiler furnace having a steam main and the usual auxiliaries, a motor for operating one of said auxiliaries, an electromagnetic reversing switch for said motor, and an integrating switch mechanism responsive to variations in furnace operating conditions and to Variations in said steam main for establishing controlling circuits for said reversing switch.

17. In combination with a boiler furnace having a steam main and the usual auxiliaries, a motor for operating one of said auxiliaries, an electromagnetic reversing switch for said motor, and an integrating switch having a pair of relatively movable contact members for establishing controlling circuits for said reversing switch, one of said contacts being operable in response to variations in furnace operating conditions and the other in response to variations in said steam main.

18. In combination with a boiler furnace having a steam main and a plurality of furnace auxiliaries, a motor for operating each of said auxiliaries, an electromagnetic reversing switch for each motor, a primary control mechanism response to variations in pressure in said steam main, a secondary cont-r01 mechanism responsive to variations in furnace operating conditions, an integrating switch having pairs of relatively movable cooperating contact members for establishing controlling circuits for said electromagnetic reversing switches, one contact member of each pair being operated by said primary control mechanism and the other contact member of each pair being operated by said secondary control mechanism.

19. In combination with a boiler furnace having a steam main and a plurality of furnace auxiliaries, a motor for operating each of said auxiliaries, an electromagnetic reversing switch for each motor, a primary control mechanism responsive to variations in pressure in said steam main, a secondary control mechanism responsive to variations in furnace operating conditions, an integrating switch for establishing controlling circuits for said electromagnetic reversing switches having cooperating contact members respectively controlled by said primary and secondary control mechanism.

THOMAS W. DELANEY.

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