US1857592A - Furnace feeding apparatus - Google Patents

Description

May 10, 1932. R. A. HAWKINS ET AL FURNACE FEEDING APPARATUS I F'iled July 51, 1930 '7 Sheets-Sheet 1 wuewtozo A A. H /v zyoo gfio W%JZHM m mwm May 10, 1932. R. A. HAWKINS ET AL FURNACE FEEDING APPARATUS 7 Sheets-Sheet 2 Filed July 51', 1930 May 10, 1932.

R. A. HAWKINS ET AL FURNACE FEEDING APPARATUS Filed July 31, 1930 7 Sheets-Sheet 3 HDM/HFD mar/mam May 10, 1932.

R. A. HAWKINS ET AL FURNACE FEEDING APPARATUS Filed July 31 7 Stieets-Sheet 4 MkK N? May 10, 1932.

R. A HAWKINS ET AL FURNACE FEEDING APPARATUS Filed July 51, 1930 7 Sheets-Sheet 5 E E E B E E E E .M E E E M B E @oooaowooooofi 0E "WM \Woon neooo onoo w HHU kw wk y 10, 1932- R.\A. HAWKINS ET AL 1,857,592

FURNACE FEEDING APPARATUS Filed July 51. 1930 7 Sheets-Sheet e my z 7 May 10, 1932- R. A; HAWKINS ET AL 1,857,592

' FURNACE FEEDING APPARATUS Filed July 51, 1930 7 Sheets-Sheet 7 Patented May 10, 1932 UN E-TEF TES my A, HAwKr-Ns, or INSPIRATION, ARIZON AND nownnnwgiwoss rmfor MC ILL, f iNEVADA:

:VFURNACE FEEDING inm tes, r v

1 7 Application filed July 31,

invention relates to apparatus for feeding charges I to metallurgical furnaces. More particularly it relates to anapparatus for automatically i' eed'ing charges at spaced distances in a furnace or the reverberatory furnace. The amount ofinateri a'l. chargedv isproporti'oned to; the rateof smelting of the charge in the furnace so as to maintain'th'e proper amount of material in the furnace 'wi'thout creating an excess or deficiency of the charging-materiala The smelting rate in a reverberatory furnace is, however, not the same throughout the entire length of the charging zone-butvarieswith the temperature in thefurnaee: I'tis a maximum at the point of maximum temperature which, when the f-urnace'i's fired? from one end, isnear that end; for example, at about ten 'feet'from the firing end" in an oil fired furnace, and is a minimum at the'opposite end of the charging zonewhich the heating gases reach after hav-' ing given up heat tothematerials nearer the firing end. g

The-objects of our present invention are to provide an apparatus in which the charges of material to-be-fed to-the furnace Will beautoinatically distributed throughout the length of the zone of the furnace and fed at the proper rate thereto to provide apparatus whereby the quantity of material-fed at each part otthe length of the firingzone is pro portioned to the rate of smelting of thematerial at the respective parts of the zone;and-

toprovide means whereby the relative'qu'antit-y of materialsupplied to each part of the chargingzone may be adjusted to suit the parti'cular conditions of the furnace.

In the accomplishmentof the above objects according to a preferred form of the invention, the charging material is continu- OHSlY fed to a conveyer and the delivery end or the conveyer' is brought in succession in position to deliver the charging materlals at 1930. Serial no, 472,044;

determined successive.intervalsin the length of the charging zone. the delivery end of the conveyerjis spotted above each of a series offeed openings spaced in the'lengt-h of'the furnace for an interval of 1 time in proportion to the quantity of charging material to b'e" fed at the respective In I this embodiment I charging opening, then moves to weed:

the length of the furnace." The conveyeris preferably so arranged that it chargesone part of the z'oneflfrom one end, and the other fromithe opposite endoii the conveyer; its di re'ctio'n of movement-and thedirection "of fspottingbeingreversedhen passing from one part to the other.

i-ng opening and thus progresses throughout" F urtherobj'ectsofthe invention aretoprovide means whereby the feeding'means is ac curately spotted over there'spectivechargfing openingsyto provide means whereby the stoppage of the delivery end ofthefeedingconveyer between a pair of successive feed openings is prevented; to'providea simple,

and effective reversing control'ior the con} veyer'ancl to provide a control inechanismxfor theconveyer and feeding materials so timed asto preventanfy undue accumulation oflma-o terial to-b'e chargedl.

Further ob'ects-vvillf appearfrom'the' 01: r o

l'ovvingdescripti'on ofthe invention;

The various features of' the'invention are illustratedin the accompanying drawings, in which"-- Fig.1 is a vertical sectional elevation of a reverberatory furnace of the center feed type and aieedin'g mechanism embodying a} pre f erred'iorm ofthe invention. p 1 Fig. 2 isja plan view offthe fu'rnaceshown in Fig.1. I o a A Fig, 3 is a section ooflthe furnace taken on: line33-of Fig. 1. a r

, Figs 4-.'isa wiring diagram of electric cir cuits controlling the .feeding neohanis'm:

' Fig.1 5 isa detail viewiofa mechanism'andz 9 Fig. 6' 1s plair'vievv 0fthe-timer'mecha nism of Fig 5r Fig. 7 is an end elevationof the timer mechanism. V

Fig. 8 is a development of the surface of a wheel or drum containing timer elements.

Figs. 9, 10, Hand 12 are views in side, in cross elevation and in detail of hopper opening and closing mechanism forming part of the feeding apparatus.

Referring more particularly to-the accompanying drawings, the invention is shown as. applied to the central feeding ofa reverbera-:

tory furnace 10. The material to be charged to the furnace is discharged'fro'm a charg ing car into a track hopperll, Fig. 3, the bottom of which consists of a pan or, apron feeder 12 driven through suitable mechanism from a motor 13 to discharge the material in a uniform, continuous stream to a side conveyer 1 1. The side conveyer 14 is driven continuously from a motor 15 and, in turn, discharges onto a cross conveyer 16 driven by a motor 17. I The charging material is con-' veye d by the conveyer 16 to the central part ofthe furnace 10 and is there dis-- charged onto a reversible shuttle conveyor 18. The shuttle conveyer 18 is of an endless belt type trainedover pulleys 19 and 20 carried on ajreversible carriage 21 which is supported on suitable rails to move back wardly or forwardly lengthwise of the furnace. i The conveyer 18 is one-half the length of the charging zone plus overrun length of one hopper and'is driven alternately from a charging opening 25.

reversible motor 22 through a train ofgears. The carriage 21 is moved back and forth lengthwise of the furnace by means of a reversible' motor 23 and a suitable worm gear connected to'the front wheels of the carriage. The motor 23'is given an intermittent-movement by means of a timer which causes the carriage 21 to move a distance between two successive charging openings 24 in the roof of the furnace 10, there being eighteensuch openings in the furnace illustrated; to then remain stationary for a determined period .of time and, thereafter, to move to a succeeding charging opening and thus to progress until its discharge end has reached the ninth The opposite end of the conveyer extends beyond the eighteenth charging hole 26 by the length of one charge hopper. This is. known as the over-run. The direction of motion of'the carriage 21 is then reversed so that the end of the conveyer 18, which is not at this time the dischargeend, is brought to and spotted'at the eighteenth charging hole 26. In moving back from this over-run position the reversing switch 95 is thrown over I so that theimovement of the conveyer18 is reversed. Inmoving back from this overrun position the carriage operates a reversing switch which reverses the direction of rotation ofthe motor 22 and of the conveyer 18 so that it now discharges from its opposite charge hopper.

end. The discharge end of the conveyer 18 is then brought successively over the charging holes from the eighteenth towards the midpoint of the charging zone until it reaches the tenth charging hole 27. The opposite end of the conveyer isthen beyond the first charging hole 241 by the length or over-run of one The direction of motion of the carriage 21 is then reversed so that the end of the conveyer' 18 is brought to and then "spotted at the first charging hole 24. In

moving back from the over-run position past 1 the first charging hole 24, the reversing switch of the motor 22 is thrown to reverse the direction of movement of the conveyer 18 and to cause it todischarge from the opposite end. The discharge end of the conveyer is then brought successivelyfrom the first charging hole- 24 towards the midpoint of the charging zone until it rea-ches the ninth charging hole 26. The cycle of operation is then repeated. j p I Each of the charging openings is provided with a feed hopper 28 and a gate 29. The gate 29-is controlled through a suitable-linkage by a pair of levers 30 and 31 which are so positioned as to be engaged by one of a pair of swinging hook arms 31a and 31? positioned at the opposite ends of the carriage 21, the first nine levers of openings 29 being operated by the hook arm 31a, and thelevers of openings 10 -18 being operated by the V hook arm 311). When the carriage 21 is moving from the first to the ninth opening. the hook arm 31a successively engagesfirst the lever 30 of each charging opening and rotates it in a clockwise direction; Thereupon a a swinging radial gate'29 secured to the lower end of the lever 30 is swunginacounter-clockwise direction about the pivot of the lever 30 to open a passage from the hopper 28 to the opening 24. When the lever 30 and the swingingradial gate have reached the limit of their clockwise direction, as indicated by the dotted lines in Fig. 9, the hook arm 31a rides over the end of the lever. In this position the lever 31 will have been rotated counter-clockwise to the position indicated in dotted lines in Fig. 9 by means of a connecting link 310. When the carriage .21 resumes its movement to the right, the swinging hook armBla engages the end of the lever 31 and swings it clockwise to the full line position,

This operation of the openlng gate-29 con tinues for openings 18'when the carriage 1s moving from the firing end and in reverse direction for openings 18-11 when the carit is receivedin a notch 31d ofthe swinging lever 31a. The movement of the carriage 21 is such that it stopsinthe over-run position-w-hen the lever 30a of the opening 25 is in open position so that the hook arm 31a does not override the end of the lever a and the upper; end of the latter remains in the notch 3161. hen thecarriage 21 resumes its reverse lnovemenujthe"lever 30a being-engaged by theflnotch 31d is rotated counter-clockwise, closing the openin 25; The operation of the closure for the opening27 is similar but in a reverse direction. The openings-.25 and 27 donot therefore, require a lever 31 or a link 310 to close the gate 29. Preferably thereis a set of opening and closing levers 30 and 31 and of links31c on each side of each charging opening as indicated in Fig. 10. This gives a balanced construction which eliminates any slewing and enables the construction to be much lighter than if a onesided construction were used.

Current for driving the motors 22 and 2.3'

is supplied through a trolley 32 and a contactor arm 33. The amount of feed per unit of time is controlled by the speed of the pan feeder 12 and'also by the amount of the gate opening above this feeder. Any adjustment of the rate of feed is, therefore, proportionate for each of the charging openings 24 to 27.

The motors 13, 22- and 23 are direct current motors and the motors 15 and 17 are alternating current motors. Power for driving the motors'13, 22 and 23 istaken from direct'current power mains 34 and 35, Fig.4, through a switch 36 to mains 37 and 38. Current for controlling the various.

motors 13, 15, 17,22 and 23 is also taken from the mains 34 and through a double knife switch 39 to the control circuit lines 40'and 4:1. 1 I v i I i i In starting the apparatus it is desirable to have the side conveyer 14 and the cross conveyer 16 in motion before the apron feeder 12 starts in order to ensure that the material delivered'by the feeder 12 to the side conveyer shall be conveyed away continuously and not accumulate before the side conveyor is in motion. is, therefore, automatically delayed: afterthe starting of themotors 15 and 17.

In starting the apparatus a push button 2 is closed, thereby closing acircuit from the wire 40 through a wire 43 and a branch wire 44-to a time limit relay 45. A circuit is also closed through a branch wire 46 to a control. relay 47. A return circuit then leads The starting of the motor 13 from tliewire 43 through a Wire;50,1to. sole: noids-51r and 52'of linestarterse53 andl 54aof l the alternating'currentimotors-15 and'17 and thence returns .throughbranchwires 55 to the 0 I I return wire41.

The solenoids 51 and 52-,thereupon actuate contactors 55 and; 56,,respectively tos'close the three alternating circuits through the al.

ternating cur-rent motors 15 and 17' a and; at a the sametime, close the contactors 57 and 58; Upon the closing of'thecontactorsfi'l andi58 the circuit through the push buttonior switch 42; isby-passed fronrthe wire 40 through a wire 49, thence through aiclosed-contactor 59 of therelay '47 and then'through'a;wire'-60;to

the contactor 57' and through the wire 50 and solenoids 51 and '52 to the r'eturn ,wire41.

The wire 50 being thus connectedtothe wire 40 also connects the wire '40 .to' the wires -44 and 46, thereby establishing a-by-pass circuit through. the relays 45 and 47"to the return 1 I wire 41*. The push butto1r42may thereupon be opened without interrupting the circuit through the relays 45, 47, 51 and 52 which-re main closed through the by-pass wire49'un til,v a normally closed push button or switch161 v is-opened. When the relay'45 is closedacircuit' is closed from the wire 40 through the by-pass wire '49 and contact 62 and thence through a wire 63 to a line starter 64. Any

turn main 38 of the motor circuits.

much as both the wires 38 and-41are connectedto the return main 35,11; connection of the" circuit from the wire 40 throughthe relay 67 to the return main38 completes a circuit through ,the relay and is somewhat more con} venient win the-preferred installation than would be a return to the'wire 41.

When current passes through the relay solenoid 67 it closes a contact 69 thereupon closing a circuit from the main-37 through.

a'branch wire 70, thence through'the contact 69 to a wire 71 leading to. a terminal 7 2 ofthe I continues through a shunt winding 7 3 and remotor 13. From the terminal-,72 the circuit turn-wire 74 to a terminal 75 and connecting wire? 6 tothe return circuit wire 68 and 38.; From the terminal 7 2 current. also flows through a series field winding 77' andjarmature winding 7 8 and thence-through a'wire' 79 to a terminal 80 of a drum controller 81.

The circuit from the terminal 80 is then connected to an outgoing terminal 82 either through theresistances 83 I or thi'ough the 'ro-.

tatable connecting contacts. 84, or through any suitable combination of-resistancesand contacts through the intermediate terminals 85. rent flows through a connecting Wire: 86to a From theoutgoing terminal 82 the 01m,

. terminal of the cut-out relay 87 and thence through resistances 88 in series to an extension of the wire 74. From this wire the current returns to the return wire 38 through the connecting wires 76 and 68. As current passes through the resistances 88 a circuit is established from these resistances through a branch wire 89 to the relay 87 which is of a retarded or slow acting type, and thence through a return wire 90 which connects with the terminal and wire 63. Current being thus established through the relay 87- causes 7 the latter to close a contact 91, thus short circuiting the resistances 88 and connecting the return wire 86directly'through the contact 91' and wires 74,76 and 68 to the return i windings 116 of the motor22 and thence main 38.

' It is to be understood that the time limit relay 45 requires a considerable time for its operation, for example, five seconds, whereas the relay 47 is quick acting. Accordingly the closing of the contact 62 and the starting of the motor 13 is delayed'for a corresponding'period after the closing of the contacts '55and 56 and the startingof the motors 15 through the contact 92 to a wire 93 and thence throu' 'h a wire 94 to a reversin b b switch 95, The reversing switch 95 controls the direction of rotation of the motor 22 for driving the conveyfer belt 18 andis itself controlled by the movement of the shuttle car or carriage 21 in such a manner thatwhen the shuttle car has reached the limit or" its movement in one direction, and starts back from the over run position it swings the reversing switch 95 to contact with a terminal 96 and, when it has reached its limit of movement in th'eopp'osite direction, and starts back from the over run position it swings the reversing switch 95 into contact with a contact terminal 97. I

The terminals 96 and 97 connect to a re versing line starter 98 for the motor 22 in such a manner as to connect the field circuits and armature" circuits of the motor 22' in reversed directions 'as one or the other terminal is connected. Any suitable reversing starter may be used, the specific construction of the starter in itself not being our invention. When the reversing switch 95 contacts with the terminal 96 it closes a circuit from the wire 40 through the wire 43, and-later through wire 49, contact 92 and wires 93 and 94 to a wire 99 which leads to a control relay solenoid 100. r

' Similarly when the reversing switch95 is connected to the terminal 97 a circuit is closed through a wire 101 and through suit able resistances to a control relay solenoid 102. From the relay solenoids 100 and 102 the circuit returns through a return wire'103 to a wire 104 leading-to return main 38-and also connecting toa terminal 105 of a reversing line starter 106 for the motor 23, the line starter 106 being similar to starter98. When the solenoid 100 is energized it closes a pair of contacts 107 and 108. A circuit'is at all times closed from, the main 37 through branch wires 109, 110 and 111 toa shunt field winding 112 and thence through return wire 113 to the return main 38. current through the shunt winding 112 is, therefore, always the same. A circuit is-also established through the wires 109 and 110 through a wire 114 to the contact 108. hen this contact is closed the circuit is, therefore, closed through a wire 115 to the armature a starting resistance and cut-out 119 to a wire 120 leading to a series field winding 121 and thence through the wire 113 tothe return main 38. WVhen the reverse switch 95contacts with'the terminal 97 the circuit through the line 99 and the solenoid 100 is broken, thereby opening-contacts'107 and 108 and breaking the circuit through the; armature winding 16 and series field winding 121, Simultaneously a circuit is established, through the wire 101 and the solenoid 102 thereby closing a pair of contacts 122 and 123' arranged similarly to the contacts 107 and 108. Thereupon current flows from the wire 114 through the contact 123 to a branch wire 124 connecting with the wire 117 and the armature 116 and thence to the wire 115.

It will be observed that in this arrangement the direction of'current through the armature windings 116 is reverse to that when the reversing switch 95 is connected to the terminal 96. At the same time current passes from the wire 115 through a connecting wire 125 and thence through the closed contacts 122 to the resistances and cut-out 119, thence through wire 120 to the series field winding 121, wire 113 and return main 38. 'In this circuit the direction of the current through the series winding 121 is the same as when the reversing switch 95 contacts with the terminal 96 so that in either position of the reversing switch 95 the direction of current through the shunt and series field winding 112 and 121 is not reversed, whereas the direction of current through the armature winding 116 is reversed. Consequently, when the reversing switch 95 contacts with the ter- 'minal 96, the motor is driven in one direction and whenit contacts with the terminal 97 it, drives the motor 22 in the opposite diw et commutator ,on'thetail pulley shaft of the cross conveyer 16. Consequently the timer. is drivenindirect relation to the speed of the feeding conveyers and a definite intervalof rest of themotor 23, while the discharge end offthefconveyer 18 is spotted? over a charging opening and, corresponds Jto a definite amountofncharged material. The tailvpulley commutator for driving'the timer serves'to provide an intermittent currentto an electro magnetic drive mechanism for the timer.

The current for the commutator is taken from thewire 4O throughthe branch-wire '43 or 49,'through the contacts 92 as described i above, thence throughwire. 93 to a branch wire 126,to an actuating solenoid 127 shown diagrammatically in Fig. 4, and in detail in Figs; 5; 6 and-7 From the solenoid 127 the current returns througha wire 128, thence throughthe commutator12 9, shown in detail inFig. 5,, andthencethrough to ground or.

to the Ereturn ire 41'by means of a connect ing wire 130; i i

"As shown in Fig; 5 the commutator come prises arotati'ng insulating, disc 131 having a conductingor metallic insert 132that is connectedto the supporting and rotating shaft 133 of the tail pulley of thecross conveyer1'6,

andthencethrough the wire130 to ground r-to-thereturn wire 41. The current conveying-wire 128 is provided .with abrush'1'34 which bears againstthe periphery of the insulatingdisc 131 andthus comes into con-'7 tact once in each revolution of the disc with the conducting insert 132, thereby intermittently closing a circuitbetweenthe wires 128 and "130 and establishing once in each revolutiony, an intermittent circuit through and intermittently energizing; the solenoid 127.

With each energization of: the solenoid1127it lifts a magneticcore 135 in the solenoid and, through-a link '1-36 secured toithe core 135, liftst'he outer end of a crank or lever 137 against the action ofthesprings 138. With each lifting of the lever or arm 137 it rotates a'limited distance on a shaft 139 on which a timer wheel 140 is also loosely, and rotatably mounted. Pivote'd to. the arm 137 is afiber dog 141 thatengages the inner periphery of thewheel 140 Sov that with eachlifting ofthe arm 1137 'a limited rotational movementdn the directionof the arrow, Fig. 5, is imparted to the wheel'140. ,Whenthesolenoidj127 be comes de-energized by the int'erruption of the current through the commutator 131; "the arm137 drawn reversely'by springs'138 v causing the dog 141 to slip revers 1y on the inner periphery of'the wheel14Q. L

' "Ihewheel140'is' revented' tromrotating reversely with the 0g "141by I means hf fa retainingpivoted'fiber dog-14:2 which is h'eld r in engagement'with the peripheryof the wheel 140 by means of a s ring 143. I; h'e wheel 140 isthus advanced a definiteamount with each rotation of the{ 'co nmutator 131 which, in turn, is controlled" by the rotation of the ta il,pulley of the cross conveyer 16;

{The extentot movement of the whee ie-0 with each energization of :the solenoid '12? may be controlled by adjustin'gfa threaded stop 144 which limits the downwardmove me"nt ofthe link 136 and arm 137. intervals between the energizing o'fthe solenoid 127 -may also be controlledby inserting additional conducting insertsor segments in the commutator .129, L '7 Thee-wheel 140 or it s periphery 'is of'metal and is connected toflthe circuit'wire126 and thus-to the ,wir'e40' by meansof a branch wire 145 which contacts with the wheel 140 or its periphery by means of a brush'l'46 'bearing. against an axial or other conducting partifi f with two series of circumierentially[spaced contacts 147 and'148, onefseries heing spac'ed axially of'the other on theperiphery of the wheel, and said contacts being. in positionto contact .successively with contacts 149' and 150 respectively mounted on a fixed insulat ing rod or 131211 151; "lVhen one of the contacts 147 contacts with the fixed contact149 it closes --a circuit from the wire 145 'to a wire l5 2 leading to the relayjiltlopf the starter 106 v anchthereby serves-V-toieonnect the motor 23 inpo'sition to run in one directionaslongas the contacts .l 47and 149 remainin contact;

; -Similarly when the contact -150is-brought into contact with the projecting contact-148 a circuit-is closed through a relay 102 of the starterlQfi. V fihe relative positions of the series of con-i tacts 147 ;and 148 are shown jin the-develop;

wire15 3 to V m 1": the periphery f@thewheeljinlugi 810i the drawings. ThQSQI'iBs of contacts1-47 containsinine contacts, each: contact correspending to one of theaopeningsjin the first nine charging. openings from the'i'firing' end of the i'furnace and being so positioned that when 'the contact 149 is in contact withany of. the contacts v147, the shuttle car is caused to m aw y om the firing endtoward th P- a1me c the u nace. 11 8, first ontac 1 of 147 $111149.causesit ecar iag tes ar up rom the love-rerun" posit on .011 QPPQ -is l ng h beyond the firs charginghQle-24- 313 spot ing sw tchthen t psi a ith lfilit hole The space of theintervalon thetiming wheel;

' vide ..tiu erfth renaming"etthecoiiveypr 18, which'in oneinstallation was about six move off the first charging hole, and to move towards the second charging hole, and so on until the ninth contact of 147 and 149 causes the carriageto move off the eighth charging hole and towards the ninth charging hole.

Similarly, contactrof the eighteenth contact 148 and 150 causes the carriage to start up in the opposite direction from the over-run position one hopper length past the eighteenth charging hole. The seventeenth contact causes the carriage to start off the eighteenth charging hole, and so on until'the tenth contact causes the car to start up from the eleventh charging hole and move on to the tenth charging hole. i v

The interval on the timer between the eighteenth and the seventeenth contacts provides time both for the time of reversing of the conveyer 18, which in the installation re ferred to above wassix seconds, and for the time of discharge into the furnace through hole eighteen. The time of discharge into theninth charging hole is determined by the interval between the ninth contact of 147 with 149, and'the eighteenth contact of 148 with 150. The time of discharge into the tenth charging hole is determined by the interval on the timer between the tenth contact of 148 with 150 and the first contact of 147 with 149. The relation of-the timer spacings, charging opening spacings, time of charging and percentage of charge of a typical installation is as follows:

Number of timer intervals Hole No. i Seconds Bridge-. 0 0

{( (Reversing) 2 {6 (Reversing) It will also be apparent that the use of two series of contacts 148 serves not only to drive the car intermittently and to proportion the length of time between movements, but also serves to reverse the direction of movement of of the timer and contacts 147 and 148 on the From the above it will be apparent that the starting of the cross conveyor motor 17 starts the connnutator contacts revolving with the tail shaft of the conveyer and as the current impulses arereceived by the solenoid magnet from the commutator the timer wheel is caused to slowly revolve. As each contact with the charging openings '1-9 is made, the shuttle car is caused to move to the opening on which it is to be spotted until the ninth open-.

ing is reached. v

The shuttle car is now at the front end of the chargingzone, being spotted one hopper length past the eighteenth hole. The next contact made isthat of the number eighteencharging opening whichcauses the shuttle car to move back toward the firing end of the furnace and its next spotting position takes place in the number eighteen charging opening.

The backward movement of the car operates the reversing switch for the shuttle belt motor, causing the belt to reverse and the feed is charged into the eighteenth opening. As the successive contacts are made the car is successively spotted 'overthe openings numbers eighteen to ten.- At'the opening ten a simi-,

lar reversal of both car and shuttle belt takes place and the conveyer againstarts, feeding charging opening number one.

A third series of contacts 155 may be pro- Vided having eighteen contacts spaced adj acent the respective contacts of the series 147 and 148 and'positioned to successively contact with a fixed contact 156 for each contact of the series 147 and 148 with their respective fixed contacts 149 and 150. The con It is desirable to have the conveyer belt 18' and the shuttle car 21 stop instantly upon the interruption of the currentto their respective driving motors. This is particularly true ofthe shuttle car 21, because if it be carried by its momentum past the charging opening over which it is tobe spotted, the op.- eration of the apparatus is correspondingly unsatisfactory.

To secure a prompt stopping of the car the starters 98 and 106 for the motors 22 and 23,- respectively, are so arranged as to short circuit'the armature 116 oftheir respective motors and thus provide a dynamic braking for these motors. v For this purpose high resistance solenoids 158 and 159 are interposed,

between the contacts 122 and 123 and the It is also desirable to havethecontactors contacts 107 and 108, respectively, so that when these respective contacts are closed their respective solenoids 158 :and 159 will be energized. Eachof the solenoids 158 and 159 controls a normally closed switch 160, 161, respectively. The contacts 160 and 161 are inserted in a circuit 162 connecting the wires l24-and 125 respectively'which, as pointed out above, connect to the terminal wires 117 and .115, respectively, of, the arma-z ture 116. It willbe apparent, therefore, that when either of'the contacts-107and .108 or 1222and 123 isfclosed, the corresponding contact 160 or .161 is opened and the circuit be twcen the wires :115 and 117 through the. connectingwire 162 is broken. When all of the contacts 107, 108, 122 and 123 are open, which is the case when the motor is idle, bothof the contacts 160and 161 are closed, thus, short circuiting the armature 116 through the wi're162. This-short circuiting acts as ardynamic brake on the-motor 2201 23, respectively, causing it to stop immediate- .l' u on the'o enin of its drivin circuit.

It isundesirable to have the. shuttle car stop atany point between any two consecutive charging openings '24. To prevent such a stopping or spotting ofthe shuttle car between any two consecutive charging openings as might be caused by an opening'of or tamperingwith the switch 61, or with the moter control switch 163 in the control line 126, means areprovided for preventing the stopping ofthe shuttle carbetween any 149 or 150 clear the contacts 147' or 148 preferably upon the shuttle car reaching its properposition'above the charging opening. This is accomplished by: increasing the speed of the timer wheel 140 during the period while the contacts 149 or 150 arein contact with the projecting contacts 147 or 148, respectively, so that thetime is proportionateiy more accurate during the periods while contact is madethrough the motor circuits.

For. these purposes the motor 23 is provided with a spotting switch 164 which is so constructed and arranged as-to be closed while and-only while the motor 23 is running. Anysuitable device maybeused for thzsipurpose, such as a solenoid-controlled by'the current through the armature of the motor 23 or by a mechanical device. The

1 closing of. the spottingswitch 164 serves to b'y-pass thecircuits through the wires 43 and 49. In 'by-passing-the circuit in this manner current is taken from the wire 152 or .153 through av resistance 165, thence Ithrougha wire 166 leadingto arelay solen-oid'167 in a lock-outrelay 168 and thence returns tothewire 41 to: a connecting wire 169.. The relay 167 is thereby energized and closes a switch 170.

65. Gurrent'thereupon flowsthrough a' branch wire 171*through zthehclosed 'switch 170 :to

a wire 172 to the spotting switch 164 and thencethrough a connecting wire 17 3 to the return wire 166. The closingof the switch 170, therefore, bypasses the current from the wire 40 directly to the spotting-switch 164 so that should any of the switches 142,- 61 or 163 beopened, the current would be suppliedthrough' the motor 23 until itheicircuit is broken 'bythe contacts 149 or 150 moving out of contact with therespective contacts147 or 148. The energization of the look-out relay solenoid 167 .also closes a switch 174, one terminal of which is .connected through a wire 17 to the wire 128 of the timer driving solenoid 127 and. to the brush 134, and the other terminalot which is connectedthrough V a wire 176 .to abrush 177, as shown more in detail in Fig. 5. It will, therefore, be;

apparent that whenever the conducting'insert 132 of the'commutator 131' contacts with either'the brush 134 or. the brush 177, an

' while the shuttle car isin motion so that the clearing of the- contacts 147 and 148 is more promptly and accurately accomplished. The operation of the apparatus is, therefore, briefly as follows: r

Y 'VVhen the switches 36 and 39 are closed the push button 42 is closed and held closed for a period of time. a Current thereupon flows from the wirethrough the wires 43 and tothe threephase starters 53and54 for the alternating current ,motors 15 and 17, thereby starting the conveyers 14] .and ,16 in motion. In the starters 53 and 54 the current passes through the solenoids 51 and 52, respectively, and thence returns to the wire 41. The solenoids 51 and 52- also close contacts or switches 57 and 58. 'Current also to the solenoid 47 and quick acting relay and thence returns by wire 48 to the return wire 41. The solenoid 47 immediately closes :a contact 59. The switch 42 is thereupon 1bypassed through the wire 49, contact 59, thence through wire and through closed contacts. 57 and 58 to the wire 50, thence through the solenoids 51 and 52 to the return wire'41. The normally open contactor or push button 42 may thereupon be released without interrupting the starters 53 and 54'. The solenoid 47 .alsoimmediately closes a contactor 92, thereupon connecting the wires 40 through the wire 49 and contactor 92' and thence throughwires 94 and 96to the reversing switch of the timer lrespectively. The

the reversible motor starter 98 of the motor The reversible starter 98 serves to connect the armature 116 and the field windings 112 and 121 of the motor 22 in one or the other of two relatively reverse connections so that the motor is' driven in one direction when the switch contacts with the contact 96 and in the opposite direction when it contacts with reversible starter 106 in such a manner that p it connects the motor 23 of the conveyer carr1age21 in such manner asyto move the car riage back from the over-run position andthen from one of the spotting openings 24 to the next opening farther from the charging end, that is, to the right of Fig. 1. When the contact eighteen of the series -148 is reached, the contacts 148 successively contact with the fixed contact 150', thereby connecting the wire 40 through the connecting wire 53 to the reversible starter 106 so as to rotate the motor 23 at respective intervals in the reverse direction and move the carriage 21 successively towards the firing end of the furnace, that is, to the left in Fig. 1. between the contacts 147 and 148 correspond to the charging intervals for their respective openings and, as shown in Fig. 8, are so positioned as to provide longer periods of charging at the openings nearer the firing end, except the nearest one, and of. progressively decreasing time intervals towards the offtake end.

The motors 22 and 23 are so arranged as to causethe upper surface of the conveyer 18 to move to the charging end, that is, to the left in Fig. 1, when the car 21 is spotted above the'first nine openings from the firing end, and to move in the reverse direction when the car is spotted above the nine openings nearest the ofi-take end.

A lock-out switch 163 is closed when the car 21 is in motion, thereby closing by-pass circuit through the wires 166 and solenoid 167 in the lock-out relay 168 and thence to the return wire 41. The switch 164 is also closed when the motor 23 is in motion, thereby closing a circuit through the wires 172 and 17 3 and contact 170, closed by the solenoid 167, and thence through wire 171 to the wire 41. This by-passes'the contacts 42, 61 and 168 and prevents the motor from stopping until it reaches a position in which'it is spotted over one of the'charging openings 24. The solenoid 167 also closes 'a contact 174 which, through the wires 175 and 176, doubles the The intervals action of the motor 129 and consequently the speed of the timer 140, while the circuit through the motor 23 is closed, and thus provides a more prompt and accurate timing of the "stopping of the motor. 158 and 159 serve to short circuit the armatures of the meters 22 and 23 when the latter are in stop position, thereby providing a dynamic braking and ensuring an automatically prompt stopping of the motor.

t will be understood that through the 45 acts to close a contact 62 some time after the closing of the contacts 59 and 92 by the solenoid 47. Upon the closing of the contact 62 current flows from the wire 40 through the wires 49 to the contact 62 and thence through a wire 63 to amotor starter 64 for the motor 13. The motor 13 thereupon starts driving the apron feeder 12 and the speed of the motor may be controlled by means of a drum controller 81. It will be evident, therefore, that all of the conveyers 14, 16 and 18 are started and the carriage 21 is in operation before any ore is fed by the apron feeder 12,.

thus ensuring against a piling up of ore before the feeding begins such as might occur if the conveyers 14, 16 and 18 were not in motion when the feeder 12 starts.

Various modifications may be made by those skilled in the art without departure from the invention as defined'in the following claims.

NVhat we claim is:

1 Apparatus for feeding charging materials to metallurgical furnaces which comprises, acontinuous feeding conveyer, means for feeding materials to said conveyer, means for driving said conveyer alternately in opposite directions,electric circuits for controlling said driving means and for timing the reversal of said driving means, a carriage for said conveyer to move the discharge ends thereof to successive positions on said furnace, means for driving said carriage in alternately reverseddirections, an electric cir-- cuit for timing said driving circuit to reverse said driving means with the reversal of said conveyer, and means for interrupting said circuit for successive intervals.

2. Apparatus for feeding charging -materials to metallurgical furnaces which comprises, a continuous feeding conveyer, means for feeding materials to said conveyer, means for drivin said conve er alternatel in o I I b n I posit-e dlrectlons, electric c1rcu1ts for controllin said dr1v1n means and for timln the The solenoids reversal of said'driving means, a carriage for said conveyer to move the discharge ends thereof'to successive positions on said furnace, means for driving-said carriage in alternately reverseddirections, an electric circuit for timing saiddriving circuit to reverse said .driving'means with the reversal ofsaid conveyer, and means 'forinterrupting said "ClIClllt'fOISUCCGSSlVG intervalsof progressively varied lengths.

3. .Apparatus for feeding chargingmate- "rials to metallurgical furnaces which comprises, a continuous feedingconveyer, means for ,feedingmater als tO'SZtld conveyer, means for driving said conveyeralternat'ely in opposite directions, electric circuits for controlling-said driving means andfor timing the reversal of said driving means, a carriage for said 'conveyer :to movefthe discharge ends thereof :tosuccessive positions on said furnace, means for driving said carriage in a1, ternately reversed directions, an electric ciricuit for timing'said driving circuit to re a verse said drlving means with the reversal'of saidconveyer, means for interrupting said circuit for successive intervals, and 'means for reversing the direction of driving of said "motor-at definite intervals. a

4. Apparatus for feeding charging materials *to metallurgical "furnaces which comp'rises, a contlnuous feeding conveyer, means for feeding materials to said conveyer, means for driving said conveyor alternately in opposite directions, electric circuits for controlling said driving means and for timing the reversal of said driving means, a carriage for said conveyer to move the discharge ends thereof to successive positions on said furnace, means for driving said carriage in alternately reversed. directions, an electriccircuit for timing said driving circuit to reverse said driving means with the reversal of said conveyer, means for interrupting said circuit for successive intervals, and means to prevent the interruption of said circuit between said timed intervals.

5. Apparatus for feeding charging materials to metallurgical furnaces which comprises, a continuous feeding conveyer, means for feeding materials to said conveyer, means for driving said conveyer alternately in opposite directions, electric circuits for controlling said driving means and for timing the reversal of said driving means, a carriage for said conveyer to move the discharge 6. Apparatus for vfeeding chargingflmaterials to metallurgical furnaces which com; prises, -a-c0nti-nuous feeding conveyer, means for feeding materials 'to said conveyer, means ;for driving said 'zconveyer =alternatel-y in tap posite directions, electric circuits, for controlling sair l driving means and-fortiming the reversal "of said dr ving means, a carriage for said conveyor to move the discharge ends thereof to sucessivepositionson said furnace,;

means I for-driving said carriage ,inwalternatefly reversed directions, an electric circuit for timing said driving means toreverse said vd-riving'means with the reversal of said conveyer, means for interrupting said circuit for successive intervals, means tolprevent the interruption of said circuit between a said timed intervalsfand 'means ,to brake said motor :at the beginning-of said intervals of 'interruptedcircuits; i g 1 7 Apparatus 1 for feeding charging mate rials to metallurgicahfurna'ces which com ;:prises, ,a continuous feeding conveyer, means for fcedlng materials lZO'SZtId conveyer, means for driving :said conveyer alternately in -op-' posite dlIYGQtlOIISyGlGCtT-lfi circuits for controll ng said driving means and for timing the reversal of: said drivingmeans, a carriage for said conveyerxto-move the discharge ends thereofito successive positions on said fun i :nace, :means for driving said carriage in;alpternate'ly -;reversed directions, :an :electric circuit for timingssaid driving circuit to reverse a said driving-means "with the reversal 101": said conveyer, means for interrupting said-c1rcuit for successive intervals, said timing means comprising a stationary contact and a drum having contacts 'at intervals positioned. to

contact with said contact during the rotationlof said-drumr i .7 p V 8. The apparatus of; claim '7 havinga pair iof-contacts one connected tOffinClIClllt to drive :said motor in one directionsand-the :other in circuit :to 1 drive :sai'd motor in zthe reverse direction,vand'twosuccessive series of con- *tac ts on the drum, :one fen one contact and the other for the opposite :contact. V

-Appa ratus for feeding charging materials *to metallurgical furnaces which comprises, a continuous feeding, conveyenmeans for feeding materials tofsaidconveyer,'means 'for'driving saidconveyer alternately opposite directions, electric circuits forcontr'o'lling said driving means and for timing the reversal of said driving means, a carriage for said conveyer to move the discharge en ds thereof to successive positions on said furnace, means for driving said carriage in alternately reversed directions, an electric cir-, cuit for timing said driving circuit: to reverse said driving means with the reversal \of said conveyer,-means1for interrupting said circuit :for successive intervals, motors for said conveyen'and :for'said feedingimeans, ;and means to automatically start said feed motorin ad- Vance of said conveyer m'otor.

10; Apparatus for charging material at spaced positions in a furnace which comprises a conveyer, means for feeding charging materials to said conveyer, electrically drlven means 'for moving the discharge end of said conveyer to the spaced charging positions of said furnace, a timer for interrupting said electrically driven means at intervals while spotted above a charging position, and means for preventing the interruption of said circuit through said electrically driven means while said means is between chargingposr tions. I

11. The apparatus of claim 10 having means whereby said'electrically driven means may be interruptedjfor difierent periods of time and at different charging openings.

12. The apparatus of claim 10 having an alarm for indicating the movement of. said electrically driven means. t

13. Apparatus for charging materials at spaced positions in a furnace which comprises a conveyer, means for feeding charging materials to'said conveyer, electrically'driven 7 means for moving thedischarge end of said conveyer alternately in opposite directions to the spaced charging positions of said furnace, means for reversing the direction of movement of said conveyer when the direction of said electrically driven means is reversed, and a timer for interrupting said electrically driven means at intervals while the discharge-end of said conveyer is above a charging position of said furnace.

14. The apparatus of claim 10in which said timer is speeded between said intervals 15. The apparatus of claim 10 in which said timer is driven from the feeding means. 16. Apparatus for charging'materials at spaced positions in a furnace which comprises a conveyer, means for feeding charging materials to said conveyer, a commutator driven by said feeding means, electrically; driven means for moving the discharge end of said conveyer to thespaced charging positions of said furnace, and a timer driven by said commutator for interrupting said electrically driven means at intervals while spotted above a charging position of said furnace.

17.'Apparatus for charging materials atspaced positions in a furnace which comnetic drive and commutator while said-electrically driven means is in motion.

18. The apparatus of claim 10 having a pair of series of'spaced contact pins on said timer wheel and contacts for one of said seat spaced positions in a furnace which com-.

prises a conveyer, a motor for driving said conveyer in opposite directions, a carriage for carrying said conveyer in opposite directions lengthwise of said furnace, means for driving said carriage inone direction, means for reversing the direction of movement of said conveyer at the time of reversal of the dircction of said carriage, and means for interrupting the movement of'said carriage at intervals with the discharge end of said conveyer spotted above a charging position of said furnace.

In witness whereof, I have hereunto set my hand.

7 ROY A. HAWKINS. In witness whereof I have hereunto set my hand. I

HOWARD WV. MOSSMAN.

prises a conveyer, means for feeding charging materials to said conveyer, a commutator driven by said feeding means, electrically driven means. for moving the discharge end of said conveyor to the spaced charging positions of said furnace,.a timer for interrupting said electrically driven means at intervals while spotted above a charging position of saidfurnace, an intermittentelectro-magnetic drive for said timer controlled by said commutator, and means formultiplying the electric impulses through said electro-mag-

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