US2074431A - Ash removing apparatus - Google Patents

Description

March 23 ,v 1937. J. G. REID. JR

ASH REMOVING APPARATUS Filed Aug. 28, 1933 4 Sheets$heet l INVENTOR cTa/z/a 6T 7:?ez'd, r71! ATTORNEY March 23, 1937.

J. G. REID. JR

ASH REMOVING APPARATUS Filed Aug. 28, 1933 4 Sheets-Sheet 2 Q9 Q9 Q9 90 INVENTOR Jazz 0. Pez'd,Jn

ATTORN EY March 23, 1937.

J G. REID, JR 2,074,431

ASH REMOVI NG APPARATUS Filed Aug. 28, 1933 4 Sheets-Sheet 5 Q0 27 J 2a [5 /Z lNVENTOR Ja'kzz G. Reid, J

ATTORNEY March 23, 1937. RElD JR 2,074,431

ASH REMOVING APPARATUS Filed Aug. 28, 1933 4 Sheets-Sheet 4 84 INVENTOR Jb/z/a 6. Pai /1 1 BY ATTORNEY Patented Mar. 23, 1937 UNETED STATES ASH REMOVING APPARATUS ."v'ohnG. Reid, 3n, Pottsville, Pa., assignor to The Philadelphia and Reading Coal and Iron Company, Philadelphia, Pa, a corporation of Pennsylvania Application August 28, 1933, Serial No. 687,173

9 Claims.

This invention relates to means for controlling the intermittent operation of devices responsive to electric currents, such as electric motors. An object of the invention is the provision of a novel relay mechanism for effectively controlling the frequency and period of intermittent operation of a device responsive to electrical energy. The invention provides, in a comparatively simple yet highly emcient manner, for wide variation in the number and duration of operations. It has been developed in connection with a temperature responsive means for the control of a motor for operating an automatic furnace, though this is but one example of the utility of the invention, and the latter is applicable generally to the control of apparatus intended for intermittent operation. A further feature of the invention comprises the provision of means correlated with the relay mechanism for throwing the latter out. of action 20 in the event that said mechanism is continuously in action for a predetermined period. Other objects of the invention comprise the provision of means for automatically returning an operation controlling means to initial position upon de- 5 energization of the relay mechanism, as well as the coordination with said mechanism of an alarm brought into action concurrently with the throwing of the relay out of action at the end of a predetermined time. Other features of the invention will be hereinafter described and claimed:

In the accompanying drawings:

Fig. 1 is a embodiment of my relay unit; one of the side walls of the casing, containing the relay motor and associated parts, being removed.

Fig. 2 is a front elevation, showing the parts mounted on the front plate of said casing.

Fig. 3 is a view in elevation looking toward the rear side of said front plate, certain parts being 40 shown in section and others broken away.

lg. l is a view in horizontal section taken on line 5-4 of Fig. 3 and looking in the direction of the arrows.

Fig. 5 is a wiring diagram showing the relay 5 mechanism correlated with a temperature responsive element for controlling a motor.

Fig. 6 is a fragmentary View partly in elevation and partly in vertical section illustrating the applicability of the invention to the control of an 50 automatic furnace.

Fig. '7 is a view of a detail, taken on line 1-1 60 thereto a worm 8. Said worm, through worm view in side elevation showing an Wheel 9, worm it, worm wheel II, and the train of reduction gearing 12-11, rotates a toothed clutch member i8 continuously and at a reduced speed as long as the motor 1 is operating. Adjacent the clutch member I8 is a similar toothed clutch member l9. Both said members are mounted on a rotatable shaft member I8 being attached to gear l'i, which is journaled on said shaft, and member I!) being slidably mounted on a square portion of said shaft. The latter, as shown, extends forwardly through the plate 2 and has secured to its forward end a disk 2!. A finger 22 extending from said disk is adapted, in the normal or initial position of shaft to engage a stop 23 secured to plate 2. A weight 24, carried by a cable 25 wound on drum 26 secured to shaft 20, constantly urges said shaft to turn into such position that said finger 22 engages stop 23, and returns said shaft into that position when clutch members it, IS are disengaged following operation of said shaft.

Whenever the clutch members aforesaid are engaged with each other and the motor 1 is energized the shaft 20 is rotated in the direction of the arrow in Fig. 1. For controlling the engagement of said members, the member I9 is, as shown, connected to the armature 21 of an electromagnet 28. For this purpose said member l9 may have a hub portion 29 of reduced diameter and a flange 30, while the armature 21 may be provided with a forked end 27', receiving said hub portion 29. A spring 3| (Fig. 4) urges said armature 21 into such position as to maintain the clutch member i9 disengaged from member l8. When, however, the magnet 28 is energized the member I9 is shifted into engagement with said member l8.

Mounted on the disk 2| and secured thereto for rotation therewith is a disk 32 provided with a plurality of pins 33 projecting outwardly from the front face thereof. Positioned in the path of said pins is a trigger element 34 pivoted on the upper end of a lever 35. A spring 36 which bears against a projection 35 of lever 35 and also against a pin 34 in element 34, normally maintains the element 34 in the position shown in Figures 1 and 2, with pin 34' thereof in engagement with an edge of said lever 35. Connected to lever 35 is a circuit closing means in the form of a mercury switch 37 of well-known type; said switch comprising a tube containing mercury, which tube, when tilted. in a given direction, brings the mercury into engagement with a pair of contacts, thereby providinga path for the flow of electric current therebetween. In the normal position of the switch 31, shown in Figures 1 and 2, the mercury is out of position for bridging said contacts, but when said switch is tilted into the position shown in dotted lines in Fig. 5 the mercury bridges said contacts and a circuit is closed therethrough. The lever is pivotally mounted at 38 and the mercury switch 3'! is shown carried by a bracket 39 mounted on the lever 35 through the medium of pivot screw 40 and screw 41, the latter passing through a slot 42 in extension 39' of said bracket. By loosening screw 4| the bracket 39 may be swung into a desired position about screw 40 and then locked in that position to the lever 35 upon tightening said screw 4| The mercury switch 31 may thus be attached in any of a plurality of positions of adjustment to said lever 35, so as to require tilting of said lever through any desired angle before effecting the closing of the circuit through said switch. Lever 35 is normally held by a spring 43 in engagement with a pin 44, as shown in Fig. 2.

The pivot 38 and lever 35 are carried by a plate 45 slidably mounted on members 46 projecting 'from the front of plate 2, which members 46 have pins 47 projecting into guide slots 48 in said plate 45. Elements 43 on the plate 2 slidably receive the edges of the plate 45 and assist in guiding the latter. Through the medium of screw 50 threaded through bracket 5| and rotatably connected at one end to a flange 52 on plate 45 the latter may be expeditiously adjusted vertically to a desired position on plate 2.

From the foregoing description it will be seen that whenever the motor 7 and magnet 28 are energized the shaft 20 is rotated, together with the disks 2| and 32, in the direction indicated by the arrows in Figures 1 and 2. In Fig. 2 the parts are shown in a position reached immediately after rotation thereof commences, the projection 22 being shown spaced slightly from the stop 23. As the rotation of said parts continues, the pin 33 shown at the left of element 34 in Fig. 2 comes into engagement with said element, with resultant rocking of lever 35 clock wise and tilting of the mercury switch 31 into a position, (such as that indicated in dotted lines in Fig. 5) wherein a circuit is closed through said switch. When said pin passes by the element 34 the lever 35 is returned by spring 43 to its normal position, restoring the switch 3'! to its normal position in which said circuit is broken. Upon further rotation of disk 32 the next pin 33 engages and operates lever 35 and switch 31, and so likewise will the succeeding pins 33, assuming the energization of motor I and magnet 28 to continue for a sufficient period. Upon de-energization of said magnet, with consequent disengagement of clutch member I 9 from its cooperating member It, the shaft 20 and disk 32 are returned to their normal position, with projection 22 engaging the stop 23. During this return rotation of disk 32 the pins 33 which engage element 34 do not operate the lever 35, said element 34 being then simply swung idly about its pivot against the action of spring 36.

The disk 32 may, as shown, be secured todisk 2| by screws 53, 53, passing through arcuate slots 54, 54 in the disk 32. Through said screws and slots said disk 32 may readily be secured to disk 2| in any desired position of adjustment about its axis of rotation. It will be furthermore apparent that the number and spacing of the pins 33 may be varied as desired.

In Fig. 5 I have shown a system including the relay elements above described forcontrolling the operation of a motor 55 in response to the action of a thermostatic switch 56. In this diagram main supply lines 57 (of 110 volts, for example) are connectable through a. switch 58. to leads 53 connected to the primary winding 60 of a transformer. The secondary winding 6! (adapted to supply current at 25 volts, for example) is connected through the thermostatic switch 56 to provide current to the relay motor 1 and clutch magnet 28, when said switch is closed, by way of the following connections: wires 62 and 53, elements 55' and 56". of switch 55, wires 64 and 55, motor 7,, wires 65 and B1, switch contact 58, bridging means 69 and contact 70, wire H, and wire l2. At the same time, current flows from said winding 6| by way of thermostatic switch 56 through the clutch magnet 23, in parallel with motor 1; such current passing from wire 55 through wire 13, magnet 28, and wire 14 to wire 61. Thus the motor 1 and magnet 28 are energized concurrently whenever the thermostatic switch 55 closes. During the ensuing rotation of disk 32 and engagement of a pin 33 with element 34 the mercury switch 31 is tilted into the dotted line position shown in Fig. 5, with resultant closing of a circuit from the main supply line through wires 15 and i6, switch 37, wire 11, motor 55, and wires 18 and 19. Motor 55 thus now operates as long as switch 3'! is in said tilted position, or, in other words, as long as lever 35 is tilted by said pin 33. When lever 35 returns to its normal position following disengagement of said pin 33 from element 34 the switch 3! is restored to its normal position, breaking the circuit through motor 55 whereupon the latter ceases its operation. If the thermostatic switch 56 remains closed a sufiicient time to cause one or more of the succeeding pins 33 to actuate lever 35, the motor 55 will be again brought into action in response to each operation of lever 35 by a pin 33. Upon opening of switch 55 the circuits through the motor 1 and clutch magnet 28 are broken, with resultant return of disk 32 to normal position under the action of weight 24, during which return the lever 35 and switch 3? remain in their normal posiiton wherein the circuit through motor 55 is broken.

One use to which the invention may be applied is the control of the operation of a furnace. Such use is illustrated in Fig. 6, wherein there is shown a portion of the combustion chamber of an automatic furnace of the type shown in the pending application of Harry A. Grine, John G. Reid, and HarryA. Wagner, Serial No. 657,538,1iled February 20, 1933. Such furnace comprises a combustion chamber in which there is mounted a rotatable grate 8|. Rotatable with said grate is a ring 82 adapted to receive ashes from said grate. The motor 55 may be geared to said ring in any desired manner for rotating said ring and said grate, and suitable means, such as a stationary blade 83, may be provided for deflecting the ashes from the ring 82 during rotation of the latter and passing said ashes into a well 84 from which they may be removed by an elevator 85 driven by the motor 55. The thermostatic switch 55 may, as shown, be mounted in a housing 86'inserted in a side wall of the combustion chamber, the end plate 81 of said chamber being engageable by the fuel and ash bed on the grate in said chamber. Change of temperature in said bed results in opening or closing of the thermostatic switch aforesaid. The parts are shown so arranged that the axis of the housing 85 is substantially on a level with the apex of the grate, though this relation may be varied. When, due to accumulation of ashes in the lower part of the combustion chamber, the temperature in the thermostatic casing is lowered to a certain point, the resultant contraction of the thermostat element 56" brings the latter into contact with element 56, closing the circuit thru the relay motor 1 and energizing the clutch magnet 28. Disk 32 is thus rotated and, upon tilting of lever 35 by the first of the series of pins 33, a circuit is closed thru motor 55 by way of the mercury switch 31. The ash receiving ring 82 and grate 8! are now rotated, and thru arm 83, the ashes are deflected from said ring and passed into the elevator well 84. The withdrawal of ashes from the combustion chamber results in lowering of the coal above the ashes with corresponding increase of temperature adjacent the thermostatic switch 58, and, upon sufficient increase of said temperature, the thermostatic element 56" moves out of engagement with element 56, with consequent de-energizing of motor I and magnet 28. If the operation of the grate and ash ring resulting from operationof lever 35 by the first pin 33 should for any reason be insufficient to cause opening of the switch 56, the disk 32 continues rotating, bringing the next pin 33 into engagement with lever 35 and again energizing the motor 55 with consequent resumption of rotation of the grate and ash ring. This is continued while the switch 56 remains closed. The duration of operation of the motor in each actuation of lever 35 depends upon the distance which the element 34 extends upwardly with respect to the path of travel of the pins 32 and this may be readily varied by adjustment of the screw 59. In short, by turning of said screw, the length of time that a pin 33 is in engagement with element 34 during rotation of disk 32 may be regulated, with consequent determination of the period of operation of lever 35 and switch 31 under the action of said pin. The grate 8| may be eccentrically mounted, as described in the pending application above specified, whereby, during rotation of said grate, a crushing action is imparted to the ashes between the grate and the combustion chamber walls, and the passage of ashes to the ash receiving ring thereby expedited.

While the invention has been developed in connection with the furnace shown in said pending application, its utility is obviously not restricted to operation of any particular furnace or to the furnace field. It is manifestly useful wherever intermittent operation of a mechanism is desired.

I further provide means for automatically throwing the relay motor 1 and clutch magnet 28 out of action at the end of a predetermined period of operation thereof, even though the switch 56 remains closed, and concurrently sounding an alarm. Such means comprises a pin 89 mounted in the disk 32 and projecting from the rear face thereof. Near the end of a complete rotation of the disk 32 in the direction of the arrow in Figs. 1 and 2, the pin 89 aforesaid strikes a lever 90, rocking the latter clockwise (as viewed in Fig. 2). Said lever normally maintains a spring strip 9| in the position shown, wherein the bridging means 69 provides a current path between contacts 5B and 10. Said bridging means may, as shown in Fig. '7, comprise contacts 92, 93 electrically connected to each other and engageable with the respective contacts 68, 19. Upon actuation of lever 90 by pin 89 the spring strip 9! disengages contacts 92, 93 from contacts 68, T9, breaking the circuit thru motor 1 and magnet 28, and at the same time engages a pair of electrically connected contacts 92, 93 with the respective contacts 94, 95. A circuit is now closed thru an alarm 96 from the secondary winding 6| of the transformer as follows (Fig. 5): From one terminal of said secondary thru wire 52,

wire 91, alarm 96, wires 98 and 99, contact 94,

the bridging means 69 comprising contacts 92, 93', aforesaid. contact 95, and wire 12 to the opposite terminal of said secondary Bl.

Upon the de-energization of magnet 28 aforesaid, pursuant to operation of said lever 90, the disk 32 is returned to its original position by weight 24 but the alarm continues sounding until the operator shifts the spring element 9| back into engagement with lever 99, in the position shown in Fig. 2. The contacts 94, 95 are now no longer bridged by electrical conducting means and the circuit thru the alarm is broken. At the same time contacts 68, 19 are once more bridged, whereby motor I and magnet 28 will be brought into action whenever switch 56 is closed.

It will be seen that the mechanism above described for de-energizing the motor I and magnet 28, and sounding an alarm, at the end of a predetermined period of rotation of the disk 32 provides a safeguard against undesirable or excessive operation of motor 55 during any period of closure of the switch 56. This is particularly advantageous when, for example, the motor 55 is connected for operation of a furnace grate and ash ring as illustrated herein. If, for example, the burning fuel bed in the region adjacent the thermostat should not descend promptlyin response to the removal of ashes thereunder, or if for any other reason there should arise any undue lag between removal of ashes and the opening of the thermostatic switch in response thereto, the operation of motor 55 under control of said thermostat might, under such conditions, result in bringing the burning fuel into contact with the grate. With the pin 89, however, so positioned as to actuate lever 99 before sufficient operation of motor to engage burning fuel with the grate, such contingency is avoided. The position of said pin 89 should be such as to permit suficient operation of the motor during any period in which switch 53 is closed, to enable the removal of accumulated ashes but not to such extent as will result in engagement of the burning fuel bed with the grate. The mechanism herein disclosed, in short, provides for operation of a motor sufficiently to accomplish a desired result while at the same time guarding against undue operation of said motor under abnormal conditions. The

time-limit and alarm control means above de-1 scribed affords the operator an opportunity to rectify the conditions which resulted in sounding of the alarm, after which the operator, by reengaging member 9! with lever 90, may again place the relay mechanism in operation.

The terms and expressions which have been employed are used as terms of description andnot of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the portions shown. and.

described, or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

I claim:

1. In a furnace, a combustion chamber, a grate for supporting a fuel bed in said chamber, means including said grate for removing ashes from said chamber, a motor for operating said ash removing means, a thermostat positioned to be responsive to temperature conditions in said combustion chamber, contacts controlled by said thermostat, a power circuit for said motor, a relay energized when said contacts are closed and deenergized when said contacts are open, said relay being operable to alternately close and open said.

determined number of said time periods should said contacts remain closed.

2 In a furnace, a combustion chamber, a grate for supporting a fuel bed in said chamber, means including said grate for removing ashes from said chamber, a motor for operating said ash removing means, thermostatic switch means comprising a temperature responsive element in a wall of said chamber, a power circuit for said motor, a relay energized by said thermostatic switch means, said relay being operable to alternately close and open said circuit through said motor for a plurality of time periods while said thermostatic switch means is closed, and means for throwing said relay out of action and terminating energization of said motor by said relay after a predetermined number of said time periods should said thermostatic switch means remain closed.

3. In a furnace, a combustion chamber, means positioned to be responsive totemperature conditions in a fuel bed in said chamber, a motor, an electrical circuit including said motor, means operable by said motor for removing ashes from said chamber, means controlled by said temperature responsive means for controlling the establishing of the circuit through said motor, a pair of contacts in said circuit, and time controlled means for alternately closing and opening said pair of contacts and making and breaking said circuit for a plurality of time periods while said controlled means are in position to close said circuit and terminating the closing of said circuit at the end of a predetermined number of said periods should said first mentioned contacts remain closed.

4. In a furnace, a combustion chamber, a grate for supporting fuel and ash beds in said chamber, said grate having its outer edge spaced from and forming an ash passage with a side wall of said chamber, means including said grate for removing ash from said chamber, a motor for operating said ash removal means, a power c1rcuit for supplying energy to said motor, thermostatic switch means responsive to tempera-- ture conditions in said chamber and comprising a temperature responsive element in a side wall of said chamber and above said grate, other switch means operable to alternately make and break said power circuit and energize and deenergize said motor for a plurality of time pe riods following closing of said thermostatic switch means, and means for throwing said other switch means out of action at the end of a predetermined number of said periods should said thermostatic switch means remain closed.

5. In a furnace, a combustion chamber, heat responsive means positioned to be contacted by an ash bed in said chamber when said ash bed exceeds a lower predetermined depth and to be contacted by a burning fuel bed in said chamber when said ash bed is less than an upper predetermined depth, means for supporting ash and fuel beds in said chamber, means including said ash and fuel bed supporting means for removing ash from said chamber, power driven means for operating said ash removal means, a power circuit for supplying energy to said power driven means, and contacts for controlling the supplying of energy by said power circuit to said power driven means, said heat responsive means being operable to close said contacts when said ash bed increases in depth and to open said contacts when said ash bed decreases in depth, and time limit switch means operable to alternately make and break said power circuit and energize and de-energize said power driven means for a limited number of successive time periods following closing of said contacts.

6. In a furnace, a combustion chamber, heat responsive means positioned to be contacted by an ash bed in said chamber when said ash bed exceeds a lower predetermined depth and to be contacted by a burning fuel bed in said chamber when said ash bed is less than an upper predetermined depth, means for supporting ash and fuel beds in said chamber, means including said ash and fuel bed supporting means for removing ash from said chamber, power driven means for operating said ash removal means, a power circuit for supplying energy to said power driven means and contacts for controlling the supplying of energy by said power cuircuit to said power driven means, said heat responsive means being operable to close said contacts when said ash bed increases in depth and to open said contacts when said ash bed decreases in depth, a relay controlled by said contacts and energized when said contacts are closed, and means controlled by said relay for alternately making and breaking said power circuit for a limited number of successive time periods should said contacts remain closed.

'7. In a furnace, an automatic ash removing mechanism and a combustion chamber, heat responsive means positioned to be contacted by an ash bed in said chamber when said ash bed exceeds a lower predetermined depth and to be contacted by a burning fuel bed in said chamber When said ash bed is less than an upper predetermined depth, contacts controlled by said heat responsive means, a time relay, circuit connections between said contacts and said relay, a motor for operating said ash removing mechanism, a power circuit for energizing said motor, said relay comprising means for alternately closing and opening said power circuit for a limited number of successive time periods when said relay is energized following closing of said contacts.

8. In a furnace, a combustion chamber and means for mechanically removing ash therefrom, a thermostat positioned to be responsive to different temperatures corresponding to changes in ash bed depth in said chamber, contacts controlled by said thermostat, a time relay, circuit connections between said contacts and said relay, a motor for operating said ash removing means, a power circuit for energizing said motor, and means controlled by said relay for establishing said power circuit a limited number of times and alternately interrupting said circuit when said relay is energized following closing of said contacts.

9. In a furnace, means for removing ash therefrom, a motor for operating said ash removing means, means for supplying energy to said motor, means responsive to the temperature of a portion of said furnace operable to control the supply of said energy to said motor, and time relay means, connected to said temperature responsive means and said motor, operable to intermittently interrupt and resume operation of said ash removing means, and to limit the total time of operation thereof independently of said temperature responsive means.

JOHN G. REID, JR.

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