US2636606A

US2636606A - Furnace feeding apparatus

Info

Publication number: US2636606A
Application number: US155476A
Authority: US
Inventors: Joseph E Dunasky; Adolph L Foell
Original assignee: Arthur G McKee and Co
Current assignee: Arthur G McKee and Co
Priority date: 1950-04-12
Filing date: 1950-04-12
Publication date: 1953-04-28
Anticipated expiration: 1970-04-28

Description

April 28, 1953 J. E. DuNAsKY Et AL FURNA'CE FEEDING APPARATUS Filed April 12, 195o 6 sheets-sheet 1 INVENToRs Jose/w f. uNAsKy By 40u/wl. Fosa sys .1:15. DUNAkY ETAL FURNACE FEE-Drug APPARATUS April 28, .1953

Filed April 1'2, v1.950

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FURNACE FEDING APPARATUS Filed April 12, 1950 6 Sheets-Sheet 4 Hoon# Fosa Apnl 28,1953 J. E. DuNAsKY ETAL. 2,635,606

FURNACE FEEDING 'APPARATUS l Filed April l2', 1950 6 Sheets-Sheet 5 452 Mvluz/ CM y 26M 24.6; Gun

. I i I 232 253 273 9 Gees 750 2 mi f4.6 J/ l .um 24" 7/ 14.55 7,/

f /vsys April 28, A1953 J. EJDUNASKY ETAL 2,636,606

FURNACE FEEDING- APPARATUS By ,40am l. facu.

Patented Apr. 28, 1953 UNITED STATES A'iEi" FFiCE FURNACE FEEDING APPARATUS Application April 12, 1950, Serial No. 155,476

(Cl. 209-24D 31 Claims.

This invention relates to an apparatus for lcharging material into the top of a receptacle and, while not limited thereto, is particularly useful for charging material in the form of discrete bodies into a rectangular shaft furnace.

In certain material treatment processes it is ,desired that the material move downwardly through a treatment zone at a predetermined rate with each of the discrete bodies or units subjected to substantially the same conditions in the same length of time. For example, the formation of pellets or aggregates from fine ore, ore concentrates, or mixtures of finely divided metalliferous material with fuel and other substances, may be effected by forming such material or materials into discrete, substantially symmetrical bodies, such as balls, and then heating. This heating, when properly effected., will harden the pellets so that they may be handled by conventional ore handling equipment and form a suitable charge for a blast furnace or similar ore treatment apparatus. The heating must, however', be carefully controlled to prevent fusion of the discrete pellets or bodies into errcessively large clusters. Consequently, all the pellets or bodies should be subjected to substantially the same temperatures for substantially the same periods of time.

In the copendng U. S. patent application of John J. Craig et al., Ser. No. 71,512, filed January i8, 1949, there is disclosed a shaft furnace in which the above-mentioned heating of aggregates or p ellets may be readily effected. In such a furnace the discharge of the hardened pellets or aggregates is effected at the bottom of the furnace at a substantially uniform rate throughout the cross-sectional area so that the indi- .vidual pellets in any transverse plane move downwardly within the furnace at substantially the same rate, thereby insuring that each pellet or aggregate will be subjected to substantially the same amount of heat in its movement through the furnace. In such an installation, it is essential that the material being treated be charged into the top of the furnace at a substantially uniform rate throughout the cross-sectional area thereof and, moreover, provision should be made for filling any voids that may occur in the top surface of the material so that the depth thereof will remain substantially uniform throughout the furnace. Moreover, it is desirable that the individual pellets or bodies of the material all .be of a size greater than a predetermined minimum value.

Similar requirements and problems are encountered with material receptacles other than shaft furnaces in which material is supplied to the top thereof, to replace that withdrawn from a point adjacent the bottom, and Where it is desired to maintain a substantially uniform prede termined amount of material in the receptacle, with the individual bodies of the material having a size greater than a predetermined minimum. Consequently, while reference has been made and will hereinafter be made to charging a shaft furnace with material in the form of discrete bodies, and while the present preferred embodi ment of the invention is particularly designed for such a use, it is to be understood that the invention is not limited to charging a shaft furnace with pellets or discrete bodies of ore, ore concentrates or the like, but may be utilized wherever similar problems arise.

An object of the invention is to provide an improved apparatus for charging material, in the form of discrete bodies, into a receptacle, such as a shaft furnace or the like, the apparatus including means to separate bodies having a size less than a predetermined value from the material as it is conveyed towards the receptacle for charging thereinto.

Another object of the invention is to provide an improved apparatus for charging material, in the 'form of discrete bodies, into a receptacle, such as a shaft furnace or the like, the apparatus including conveyor means for conducting the material from a source of supply to a classifying mea-ns which removes bodies of a size less than a vpredetermined minimum and delivers the remainder of the bodies to another conveying means which in turn deposits the bodies in the receptacle, the classifying means being so ccnstructed and arranged that it delivers the material bodies to the last-mentioned conveyor means with a substantially uniform distribution transversely thereof, whereby only bodies of the material having a size greater than a predetermined minimum are charged into the receptacle and the charged material is distributed substantially uniformly therein.

A further object of the invention is to provide an apparatus for charging material into a receptacle, such as a shaft furnace or the from which material is removed adjacent the bottom thereof, the charging effected by reciprocating conveyor means in a manner. to provide and maintain the top surface of the material in the receptacle substantially level and at a substantially constant elevation.

An additional object of the invention is to 2,636,666 l' I v provide an apparatus of the type referred to in the preceding object and in which means are provided to selectively effect automatic reciprocation of the conveyor means or manual control thereof, thereby effecting charging of material in substantially uniform layers and facilitating filling of `any voids which may occur in the top surface of the material within the receptacle.

A still further object of the invention is to provide an apparatus for charging material into the top of a receptacle, such as a shaft furnace or the like, with a substantially uniform distribution of the material throughout the cross-sectional area of the receptacle, which apparatus comprises conveyor means adapted to transport the material from a point of supply to the receptacle, means moving the delivery end of said conveyor means transversely over the said receptacle to distribute the material therein, indicating means having a portion movable transversely of the receptacle to detect the top level of the ma terial therein, and manually operable means to vary the transverse movement of said conveyor means, whereby voids in the top surface of the material in the said receptacle are detected and filled.

An additional object of the invention is to provide an apparatus of the type mentioned wherein means are provided to screen the material while conveying the latter from a point of supply to the receptacle so that only bodies of the material having a size greater than a predetermined minimum are charged into the receptacle. the screen means being so constructed and actuated as to effect uniform distribution of the material transversely of the screen and of the conveyor means transporting the material from the screen to the receptacle being charged.

A more specific obiect of the inventionis to provide an improved apparatus for charging material, in the form of discrete bodies, into the top of a receptacle from which material is removed adjacent tbe bottom thereof, the said apparatus comprising a power driven carriage reciprocable adjacent the top of the receptacle,

screen means on said carriage to which the roaterial is supplied. and conveyor means positioned to receive. material passing over said screen means with the said conveyor means loeinfy conn nected with said carriage and reciprocated theref by over the receptacle being charged. there being power means for effecting automatic reciproca tion of said carriage and operator actuated means to selectively control recrrocation whereby only bodies of the material having a site greatject. which apparatus also includes feeler means reciprocated with said conveyor means over lthe surface of the material in the receptacle. the

said feeler mea-ns being connected to signal means thereby enabling the operator to determine the nature of the top surface of material.

of said carriage. thus facilitating controlling the charging of said receptacle from a location remote from the latter.

A still morespecii'lc object of the invention is in the receptacle and to control reciprocation 4 the provision of an apparatus for charging material, in the form of discrete bodies into the top of a receptacle, such as a shaft furnace or the like, comprising a power driven carriage mounted for reciprocation adjacent the top of said receptacle, power driven screen means on said carriage and power driven conveyor means for conducting material to and from said screen means with the conveyor which conducts material from the screen means having its delivery end reciprocable over the top of said conveyor as the result of reciprocation of said carriage; and means controlling the several power means for operating said carriage, screen means and conveyor means to effect starting and stopping thereof in a predetermined sequential order.

The invention further resides in certain novei -features of construction and combination and arrangements of parts, and further objects and advantages thereof will be apparent to those skilled in the art to which it pertains fromthe following description of the present preferred embodiment thereof, described with reference to the accompanying drawings, in which similar referf ence characters represent corresponding parts in the several views, and in which:

Fig. 1 is a side View of an apparatus constructed in accordance with this invention and adapted for charging a rectangular shaft furnace, the view being principally in elevation but certain parts being broken away and others shown in section;

Fig. 2 is a top plan view of the apparatus illustrated in Fig. 1 but removed from the furnace;

Fig. 3 is a longitudinal sectional View of the conveyor means of the apparatus which is -reciprocated over the furnace or other receptacle being charged, the view being to an enlarged scale with respect to Figs. l and 2;

Fig. 4 is a top plan view of .the conveyor means illustrated in Fig. 3 with portions of the conveyor belt removed to more clearly illustrate the construction;

Fig. 5 is a sectional view taken substantially on the section indicating line 5 5 of Fig. 3;

Fig. 6 is a longitudinal sectional view through the lower part of the movable carriage of the apparatuswith certain parts broken awaythe view villustrating the drive for the carriage and for the conveyor means provided to remove material passing through the screen means;

Fig. 'I is a top plan view of the apparatus i1- lustrated in Fig. 6, a portion ofthe conveyor belt being removed to more clearly illustrate the construction; l l

Fig. 8 is a fragmentary lsectional view,I with parts broken away and others shown in .elevation. illustrating the mannerin which material is supplied to the apparatus, the' View being taken substantially on the line 8 3 of Fig. l;

Fig. 9 is an enlarged view, partly in section and partly in elevation, taken substantially on the line 9--9 of Fig. 1 and illustrating the feeler members of the indicating means;

Fig. 10 is an enlarged fragmentary View of one of the feeler means and the support/therefor il.- lustrated in Fig. 9;

Fig. ll is a front elevational view of a main control panel for the apparatus;

Fig. .1.2 is a. front elevational view of an auxiliary control panel for the apparatus: v

Fig. 13 is a fragmentary detached view to an enlarged scale of one of the supports for the screen means;

:the frame 22.

In the embodiment shown, the plates 6T are pivoted to bolts 69 secured to the brackets G6 and one or more plates or wedges 1l) are inserted between the plates S1 and the frame S5. Hence, when a thrust is applied to the frame 65, the plates 6'! tend to ride up the wheels B4 imparting both a forward and upward motion to the material upon the screen, the extent of which motion may be altered by varying the inclination of the plates 61. The material is thus fed forward and is simultaneously screened, the smaller particles falling through the openings of the plate 59 or of the screen Si.

The classifying means or screen means 53 is moved or vibrated by a suitable mechanism 7l. In the illustrated embodiment the mechanism shown is of the type Deister Concenco head motion or mechanism and comprises an eccentric on a rotatable shaft connected to the screen means 58, by suitable links and a coiled spring, for imparting oscillatory movement to the screen means, the shaft of the mechanism 'H being driven by an electric motor '12. The mechanism 'H and motor 'l2 are mounted upon a supporting frame 'i3 secured to and extending rearwardly from the support i. This support is preferably weighted or loaded to prevent undesired vibrations from being transmitted to the frame 22 of the carriage. Preferably the width of the classifying means or screen 53 is substantially the same as the width of the furnace, or other receptacle, to be charged and the sides of the frame 65 are provided with upstanding guard rails or flanges to prevent the material from dropping over the sides of the screen. The rate of feeding l the material over the screen may be adjusted both by varying the inclination of the plates 81 and by varying the speed of the motor l2. Uniformity of distribution of the material transversely of the screen is effected by inserting shims or wedges between the posts or standards 55, 5S and the support 51.

It will be apparent that any material placed adjacent the upper end of the screen means 58, the right-hand end as viewed in the drawings, will feed downwardly thereover and be discharged from the lower end thereof. During this passage y'of the material over the screen, any bodies of the material having their greatest dimension smaller than the openings in the screen will drop therethrough so that only bodies or pellets of greater than predetermined size, whichv size is determined by the mesh of the screen, can be fed to the furnace, or other receptacle. The material which `drops through the screen, due to its small size, is directed by means of a chute 'I4 onto a belt lconveyor 'i5 which is supported upon the carriage 2| and has the top iiight thereof moving in a direction from left to right as viewed in Fig. 1.

As shown in Figs. 6 and 7, the belt 'l5 is driven by means of an electric motor 75 supported upon the frame 22 of the carriage 2i and driving a sprocket 'H through a speed change unit 78. The sprocket 'Il is connected by means of a chain I9 with a sprocket wheel 8i), which is in turn keyed or otherwise secured to the axle 8l of the driving drum 82 for the belt 15, this belt drum 82 being supported by suitable bearings, such as 83, upon Adjacent the opposite end of the frame 22 is an idler belt drum 84 about which the conveyor belt 'l5 passes, this drum 84 having its bearings adjustably secured to the frame 22 so that the said drum 84 may be moved longitudinally relative to the frame 22 by means of adjusting screws, such as 85, in a well known manner totake up slack in the belt `'15. The belt 'l5 is supported intermediate the drums 82 and 84 by idler rollers, such as 86 and 81, extending transversely of the frame 22 below the upper flight of the belt 15, and by a roller 88 likewise supported upon the frame 22l and extending below the lower flight of the belt.

Material passing through the screen 58 is, as mentioned above, directed by the chute 14 onto the conveyor belt 'I5 and the latter moves this material towards the right-hand end of the carriage 2l, as viewed in the drawings, the material being discharged therefrom through a chute 89 which is supported intermediate the

tracks

38, 39 on' which the carriage 2l runs. This chute 89 is normally stationary and therefore has a length such that the delivery end of the conveyor 'l5 is at all times over a portion of the chute 89 regardless of the position of the carriage 2| in its reciprocatory path. Material discharged through the chute 89 is received upon a suitable belt conveyor 9G and is carried by the belt conveyor to a suitable place of discharge. Where, as in the described embodiment of the invention, the material handled is raw or unheated pellets of iron ore agglomerates, the material passing through the screen and carried away by the conveyors 15 and 9U may be returned to the pelletizing apparatus for recirculationV therethrough or may be otherwise disposed of as may seem expedient at the time. A chute or shield 3| is supported upon the frame 22 of the carriage adjacent the discharge end of the conveyor belt 'I5 to guide the material from the belt into the chute 89 and lpreventsuch material from being thrown upon the portion of the frame on which the electrical motors 49 and '16, together with the change speed units 4l and 78, are supported.

The material passing from the delivery end of the screen 58 is delivered into the furnace 2U by a conveyor means, generally designated 92. This conveyor means comprises a framework 93 formed of suitable structural members welded or riveted together, with one end connected to the portion of the frame 22 for the carriage 2l acl- `iacent the delivery end of the screen 58.' The frame 93 is provided, adjacent its ends, with transversely extending axles 9d, 95 on which are mounted pairs of iianged wheels 9B and 91, respectively, adapted to run upon rails, such as 98 and 99, see Fig. 9, supported adjacent the top of the furnace 20 and at leither side thereof. The

rails

98 and 99 are parallel with the previously mentioned

rails

38 and 39 so that the conveyor means 92 is reciprocated in a straight line when the carriage 2l is reciprocated by operation of its motor 4S. Movably supported upon the frame 93 of the conveyor means Q2 is a suitable conveyor belt |08, which in the present instance is shown as formed of woven wire or other heat resistant material. This conveyor belt lili! may, however, be formed of fabric, rubber, or mixtures thereof when the temperature at the top of the receptacle or furnace 20 is not high enough to damage (such materials.

The conveyor belt l0!) is adapted to be driven by a motor l0! which is suspended below the frame 93 adjacent the connection of the latter to the carriage 2i. This motor lill drives a sprocket [82 through a change speed unit I U3, the sprocket W2 being connected by a chain i812 to a sprocket wheel 85, which is keyed Or otherwise connected with an axle |86. The axle 108 is provided with a driving drum |01 for the conveyor belt |00 which passes therearound aeeaooc and around an idler drum wir ad-iustably supported upon the frame 93 adjacent the other end thereof; Adjustment of the position ofv the Hi8, and hence of the amount oi slack inthe conveyor belt Hill, is effected by means of screws, such as lille, in the conventional man ner clearly apparent from an inspection of Fig. e.

`Bue to the fact that the belt i9@ is formed ofwire mesh, 'woven wire, or the like, and because it is to support pellets of iron ore aggiorn-crates, the combined Weight' of the belt and its material is relatively high. Moreover, since itis desired that there be no substantial troughing action of this belt, in order that the pellets will reina-inuniformly distributed thereover un til deposited in the furnace, the upper flight or' the belt is supportedupon a plurality of idler rollers lill' and' lli which extend angul-arly towards each other in a herringbone pattern, see Fig. 4. As shown therein, one end oi each oi the rollers lill, l'l-i is journaled in a bracket such as N2, H3, respectively, supported upon oppo site sides ofthe frame 93, the adjacent ends of the rollers No; ttl being supported inbrackets llt and H5, respectively, located substantially medial'l'y of the fra-nie il@ upon a suitable longitudinally extending portion H thereof. The lower orv return night ofv the` belt, since it does not carry the Weight of material being charged may be supported* upon a relatively few idler rollers, such as lll, which extend transversely of the conveyor belt illu in the conventional manner. .li slack takeup adjustment for' the belt is shown as comprising a pair of idler rollers lit', H9 mounted on opposite sides of the lower ilight of theY conveyor belt and supported at' their opposite ends by links or bars such as mi and |2, these bars being pivoted to the' frame 93 as' indicated at 122 and i231 It will be apparent that the tension of, the belt mit may be readily adjusted by altering` the angularity of the bars 1:28 and l2! which may be secured in an adjusted position in a conventional manner.

The width oi the conveyor belt ict is substantially equal to the Width of the opening at the` top or the shaft furnace 20, or other receptacle to which the material is delivered, and the length oi distance. through` which the delivery end or" the belt liiii is moved is substantially equal to the other transverse dimension ci the opening at the top 'of the shaft furnace or other receptacle. Consequently, the pellets, or other` material, are deposited in the furnace, or other receptacle, as substantially uniform layers across the entire cross section thereof when the conveyor belt itil is driven and reciprocated. En order to prevent excessive pilingv up of the material adjacent the left-hand and right-hand side walls of' the furnace, as viewed in the drawings,` when the conveyor reverses its direction of' movement, the length of reciprocating stroke of the conveyor is preferably made slightly' less than the actual transverse dimension of the fun nace or other receptacle in this direction, so that the` delivery end or' the conveyor belt stops 1n itsfreciprocatory movement somewhat short of' the inner faces of these walls oi the furnace or receptacle 2b. This is desirable be'cai.rse, during the change of direction of reciprocation, the

delivery end of the conveyor will be over a given.

area of the furnace 2e or other receptacle adjacent the said side wallsy for a longer lperiod of time than it is over an area of corresponding size intermediate these side walls, as for example, adjacent the centeroi the receptacle.

By the. mechanism thus far described, it will be apparent that the material supplied to the upperv end of the screen or classifying means- 58 will be delivered with a substantially uniformdistribution over the discharge encl of the conveyor belt tot so as to form successive lay-f ersl oivmaterial within the receptacle or furnaceA 2li of substantially uniform thickness throughout the cross-seetional area thereof. This theoretical distribution of the material is not, however, likely to vbe achieved at' all times during the normal automatic operation of the apparatus, t'liisA bei-ng due, for example, to the manner in which-the material is withdrawn from the bot-V tom ot the furnace, and perhaps to other' causes. lin any event, it is essential that no appreciable voids occur in the upper surface or the top levelofj material within the furnace 2U since this would change the relative amount of heat tol which the particles' in the various parts of the furnace were subjected. Therefore, an indicating' means is provided by which the top surface or' stock level of the material within the receptacle or furnace 2u may be detected, and pro'- vision is also made for manually interrupting or otherwise controlling the cycle of reciprocation of the conveyor lou so that, when detected. voids or irregularities in the surface of the material inthe furnace l can be readily corrected'. The indicating means may take a variety' of' different forms but, in the present preferred embodiment, comprises a plurality or feeler means which are adapted to he reciprocatedl transversely4 oi the receptacle over the top Surface of'` the material therein and to indicate the presence of the material by contactI therewith.

As will be seen from Figs. 1, 3, 9` and l0, the' feeler membersI of this indicating means, in the present' embodiment, comprises a pluralityA of metal chains 12st. These chains are preferably eachindividually supported upon an insulating, spool or member l25, the spoolsbeing supportedi upon axles such as l2i mounted in andl carried by separate, substantially U-shaped, brackets i2? which. are welded or otherwise secured to the under side of a transversely extending member mit. rThe member H26' is preferably sup'- ported in an inclined position adjacent the discharge end of the conveyor Hill, as Will be seen fromFi'g.. 3, by downwardly extending arms or brackets such as l2`9 carried by` a transversely extending member i3d secured to the frame 93 of the conveyor Hill. By this construction the transversely extending memberv |28 forms a shield preventing pellets or other bodies of material, which are discharged from the belt lLU', from striking or otherwise directly contacting the chains lill as Well as providing a support for the latter. The transverse member |28 also aids in spreading or directing the how or' the pellets discharging. from the end of' the con veyor i507..

liiach` of the chains l'24 is provided with a connection i131' to an electrical cable or conductor |232'v leading. to ay suitable control panel or panels having. signal lights whichY are adaptedv to be illuminated only when the corresponding chain li2'4 engages pellets within the furnace 2li', as will be hereinafter described. Since the conveyor IDU is normally automatically reciprocated over the top or" the furnace 2i), it will be apparent that the' chains i211' continuously move back and forth. over the surface of the material in the `furnace. Whenever one of the chains contact .portion of the 'material in the furnace, a circuit is closed lighting the corresponding signal light whereupon the operator may terminate the feeding of material, as hereinafter described, until the signal light is extinguished. Preferably, however, the carriage will be allowed to operate continuously so long as all the signal lights are illuminated and manual control of movement of the carriage and of the feeding of the material will be invoked only when one or more of the signal lights is extinguished to thereby effect lling of a void in the top layer or the surface of the material whichris thus indicated.

In addition to the above mentioned conveyors and screen means, the carriage 2| is also provided, adjacent the endV thereof opposite that carrying the conveyor |50, with upwardly eX- tending support members, such as |33, which carry a conveyor frame |34 at the top thereof, the latter being further supported or braced by diagonally extending members such as |35. The conveyor frame |34 is provided with a suitable conveyor belt |35 which is driven by an electric motor |37 through a suitable speed change unit |38, see Fig. 8. The conveyor belt |36 is of substantially conventional construction and hence need not be described in detail. Suffice it to note that the upper flight of the belt is supported upon suitable idler rollers |39 and the end of the frame |34, adjacent the screen or classier 58, has a downwardly inclined portion |43 in which is supported the forward or idler drum |4| for the conveyor belt |35 so that this portion of the conveyor is closely adjacent the upper end of the vibrating screen. The lower flight of the conveyor belt |36 is supported by suitable idler rollers |42 and shields or guards |43 are provided adjacent the opposite sides of the belt |36 to prevent displacement of the material therefrom. The relationship of these guards or shields |43 and their manner of support upon the frame |34 will be readily apparent from Figs. l and 8 and hence need not be described in detail.

The material is brought to the reciprocating carriage and the conveyor means thereof from a source of supply, such as a balling drumbr the like, not shown, by suitable conveying means adapted to deliver the material to the conveyor |38 at all times during reciprocation of the carriage 2|. For this purpose the apparatus preferably includes a power driven conveyor belt |44,

see Fig. 8, the delivery end of which is mounted adjacent the upper flight of the belt |35, the belt |44 being driven by a motor |45 operating through a change speed mechanism |45. Preferably a delivery chute |41 is supported upon stationary means, not shown, adjacent the end o'f the belt |44 so that the material delivering therefrom is deposited upon the belt |36 as the latter reciprocates,therebeneath during the operation of the carriage 2|, the forward position of the carriage being indicated in full lines in Fig; 1 with the position of the conveyor |44 indicated in broken lines thereabove. The rearwardmost position of the carriage 2| is indicated in broken lines in Fig. 1 and for this position of the carriage 2| the conveyor |36 thereof will have lrnovedso that the chute |41 and conveyor |44 are adjacent the inclined portion of the conveyor |35. As a positive means of stopping and preventingovertravel of the carriage 2| in either direction the

rails

38 and 39 are preferably provided with arcuate stop blocks or wheel clogs "The-motor 43 for the carriage 2| is preferably of the. direct current, compound wound, `reversi-` 12 ble type. The motors T6, lill; |31 and |45 `for the conveyors 15, |30, |36 and |44, respectively, are also preferably of the direct current, compound wound type, but need not be, and preferably are not, reversible. The motor l2 for the screen means 58, however, is preferably of the three-phase, alternating current type. In normal operation, these motors and the indicating means for detecting the top surface or stock line of the material in the furnace 20 or other receptacle are energized and deenergized in a predetermined sequence to insure proper move` ment of the material being charged and to prevent piling up of the material in any one part of the feeding apparatus. The order of starting is: first, energization of the indicating means and of the carriage motor 49 with sequential energication of motors '16, 12, |31 and |45 in that order after the motor 49 is energized. Stopping of the motors is effected in the same order and stopping of any motor stops all other motors preceding it in the said sequential order. In addition to this sequential control, provision is made for temporarily stopping the carriage reciprocating motor 49 without interrupting energization of the other motors. Means are also provided to permit manual reversal of the motor 49 independently of the position of the carriage relative to the switches 50 and 5| which control automatic reversal thereof. In addition means are provided to permit individual manual control of the operation of the indicating means and of each or the motors, this manual control being for the purpose of setting up, trial operations, and the like.

The manually operable switches, and the relays controlling the operations of the motors and of the indicating means are schematically illustrated in the simplified wiring diagram comprising Fig. 14, it being understood that conventional devices such as current limiting resistances, overload devices, fuses and the like have been omitted for the sake 0f simplicity. The relationship of the operating coils of the relays and the contacts operated by each of these coils Will be apparent from the key diagram comprising Fig. 15 which is so constructed that, when placed side by side with Fig. 14, the coils and contacts shown in the two figures and bearing like reference numerals are in horizontal alignment while all contacts operated by a given relay coil are shown in Fig. 15 in vertical alignment with each other and with its operating coil.

Referring now to Fig. 14, it will be seen that power is supplied to the circuit through power supply lines LI, L2 and L3 which are connected to a source of electrical energy of the threephase, alternating current type. The power lines L|, L2 Vand L3 are connectible to the wires |50, |5| and |52 of the circuit for the apparatus through a disconnect switch |53. Connected to the wires |50, |5| and |52 is a three-phase alternating current motor |54 which has its shaft operatively connected to drive a direct current generator |55, the output wires |55 and |5l of the latter being connectible to wires or bus bars |58 and |59 by means of a disconnect switch |60.

The wires or 4bus bars |58 and |53 supply direct current electrical energy for both the ccntrol and the energizing circuits of the motors 49,

y 16, lill, |31 and |45. Thus, the wire or bus bar |58 is connected with a wire or bus bar |S| forming one main power lead for the control circuits of these motors, the wire or bus bar |53 being' connected with Wire or bus bar |52 form- 2M4. Closing .of the contacts 2MI provides a. holding circuit about the contacts 2CS2 thereby maintaining the relay 2M energized after the manually operable switch I8 has been released with consequent deenergization of relay ECS and opening of contacts 2CS2. f

Closing of the contacts 2M2 and 2M3 completes a circuit energizing the indicating means. Thus, as will be seen from the upper right-hand portion of Fig. 14, the primary |99 of a transformer for the indicating means is connected to the Wires I5() and I52 while the secondary 266 thereof is connected through the previously closed manually'operable switch H3 to one side each or" the normally open contacts 2M2 and ZMS. rIhe'other side of the contacts 2M2 is connected with a wire I which is in turn connected to oneterminal each oi' a plurality of pairs of indicating lamps 262, 203, the other terminals of which are connected with the ieeler means or chains' |24. The contacts ZMS are connected by suitable conductive means so as to be in conductive relationship with the material P within the furnace. This may be effected, for example, by connecting a wire 204 between the contacts ZMS and a metallic portion of the furnace so that the circuit is completed through the latter to the material M therein,` which in the present instance is electrically conductive, being pellets or agglomerates of iron ore or the like.

5 As shown in Figs. such as 9 and 14, the indicating means comprise four of the spaced chains 124, the lower ends of which are adapted to contact the upper surface of the material P, the

upper ends of each of the chains being connected by the wires |32 to corresponding terminals of a pair of the indicating lamps 262, 20S, the other terminals of which are connected with the wire ZI. The several lamps 202, 263, which are preferably red, are identical but are located at different control stations, all of the lamps 202 being at one control station while all of the lamps 20S are at the other station. Hence, when the relay 2M is energized, as just described, the lamps 202, 203 associated with any chain |24 which contacts the upper surface of the material, such as pellets P, are illuminated. The lamps associated with the chains 126 which are out of contact with the material are not, however, illuminated. It is therefore possible to easily determine at a glance whether or not there are voids in the upper surface of the furnace or other receptacle, it being remembered that the chains I24are continuously reciprocated back and forth over the'surface of the material in the receptacle due to movement of the carriage.

Signal means are preferably provided to permit determining from a remote point whether or not the carriage is in operation and the indicating means energized. For this purpose, one or more red lamps, such as 21235 and 206, may be placed at diierent points about 'the plant in which the apparatus is located, these lamps being lighted when the carriage is in operation due to the closing of the contacts ICR-4 in the control circuit as a result of energization of relay ICR. At the same time, similarly located green lamps 21 and 268 will be extinguished by corresponding opening of the norniaily closed contacts ICRE. When the carriage is not in operation, relay ICR. is deenergized so that the green lamps 20'! and 208 are lighted and the red lamps '265 and 266 are extinguished. Likewise. red lamps 269 and ZIB are controlled by the contacts 2M4 of relay 2M and green lamps 2II and 212 are controlled bythe contacts 2M5 of relay 2M. Hence, wheny the'stock level indicating means is energized, the red lamps 269 and 2I are lighted due to closing of contacts 2M4 and at the same time the green lamps 2H and `2I2 are extinguished due to openingof the normally' closed contact 2M5. When the stock level indicating means is deenergized, however, lamps 2tlg and 2 I0 are extinguished and lamps 2II and 2I2 are lighted.

vThe 4previously mentioned closing of the contacts ICS2 has completed a circuit from'the wire ISI through the manually operable, normally closed, stop switch 2IS to and through the contacts ICS2, contact 2 Illa of a push button switch 2id, thence to and through the coil of a relay ECR to the wire |62. Hence, the relay 2CR is energized and closes its normally open contacts 2CRI and 20H2. The'closing of the contacts 2CRI completes a circuit therethrough and through contacts ICRB of relay ICR, whichv were closed in response to the previous energize.- tion of relay ICR, to and through a relay l3M to the wire I62. The resulting energization of relay 3M closes its normally open contacts SMI and SM2. Closing of the contacts SMI completes a circuit through the now closed contacts ZCRZ and SMI in parallel about the contacts ICS2 so that the relays 2GB, and 3M remain energized when the contacts ICS2 open in response to deenergization of relay ICS when push button IM is released. The closing of the contacts SM2 energizes the motor IUI since the manually operable switches IILi and II5 were closed in the initial setup of the machine, this energizing circuit extending from Wire ISS through the switch V14, contacts SM2, the armature IQIa, the series eld coil Iii Ib and the switch I'I5 to the wire I64. The closing of the switches IM and |15 also provided a circuit through the shunt field coil IIlIc and the adjustable rheostat 2I5 in series there-I with. This places the conveyor IUI) in operation which is evidenced by lighting of the red lamp ZIE and extinguishing of the green lamp 2H due to the simultaneous closing and opening, respectively, of the contacts ZCRS and 2CR4 of the relay 2CR in the control circuit.

The previously mentioned closing of contacts ICSS of the sequence control relay ICS has completed a circuit from the wire I6I through a normally closed, push button, stop switch 2 I8 to and through the said contacts CSS and thence through the normally closed contact 2 I 9a of push button switch 2I9, the circuit extending through the coil of relay SCR to the wire I62. The relay SCR is therefore energized, thereby closing its.

normally open contacts SCRI, 3CR2 and SCRS and at the same time opening the normally closed. contacts SCRA. now completes a circuit through the coil of relay 4M, this circuit extending from the Wire I6I through the push button switch 2I3, the now the conveyor I5 Vsince the manually operable Closing of the contacts SCRII Closing of the contacts #M2 energizes the motor 76 for effecting driving of y switches |16 and |311`l the motor circuit were closed in the initial setup of' the machine. This energizing circuit for theA motor T6, as shown at the rightof Fig. 14, enter-idsg from the wire |63 through the switch I'If,l contactslli/I2, the arrnaturel a of the motor, the series; 'fieldE 76h of the motor and switch If'llY to the Wire |64', the shunt field 16o and the rheostat 22H- forthe motor le'i having been energized by the' closing' oi? the switches |16 and llf'l during: the initiall setup. The fact thatthe': motor 1.6 is'in operation is indicated at the control-stations since'y closingoff the contacts 3CR31 hasenergized the real signa-ll lamp 22| while opening ofthe'.contacts I'C'RA'I` has' eleenergized the green signal lamp 2222.

The closing of the eontacts-ZCSi, seethefupper lefthand portion of' Fig".- 124', of the' sequence control relay ECScompl'et'edl al circuit frei-ri the Wire 68 through the normally closed, `1nanuall-y' oper-A able, push button switch 2231 and? through the now closed contacts'- -2CS!|,. to and through the norm-ally closedl contact 22'4'c etV a push 'button switch 221i, the: ci-rcuit'contnuing tothe wire |1619 through the coil of a relay' QCR; The resultingi energization of relay 4GB; causes the latter to close` its normally open'-y contactsl 'CRI-f, 40H2, 4CR3, -fCR'ti andl open its normally closed conn tacts llCRl. The p'revicuslymentionedenergiza'- tion` of the. relayvr SCRL in the control circuit for motor 'l' of conveyor 'lf'has also closed its coritacts iCRz. Hence a cir-cuit is now completed from the:` wire Hi8;` through the switch 225iand the now closed contacts- 4CRli and SURE toand through the ooit off a. relay' to'l the. wire itt, This energizesl relay causing it to'v close its normally open contacts"l EME-'3 oli/i2', tit/L3; and eli/lt. rEhe closing ofthefcontact's-Eli/Lil completes a circuit through the now closed contacts @CRE and 5M i, which are-in parallel with the: contacts ZCEH, thereby providing al holding circuit for relay GCR' maintaining it energized after the contacts @CSP open Whenthe relay S deenergized as the result-of release of the' pushbutton Hl. The closing ofthe conta'ctsl'M', iM/32 and 5MG effects energization of the motor li! for shaking" the screen means? 58'" since the manually operable switch. HiJiwas closed-in initially setting up the. apparatus for-operation. The' closing of the contacts CRS has energzedf the redl signal lampl while the opening ofthecontacts tCRft has deenergizedthe' green lamp 226, thereby indicating thatv the screen means 5% isy now in op'- eration.

The energizaton of the sequence control relay lGS and`v theV consequent" closing" ofA its contacts iCSl" has' completed a circuit from* the-wire h6! through the manually operable push button switch 22T to andz through they said: contacts |CS4, andl thence through the" normally closed Contact' 228e' of a pushbutton switch 212B; to and throught the coil offa relay' SCR' tot the wire |62; The resulting ener-gization'of therelayECR closes its normally open contacts ECHT, ECR-'2; ECR-3; 5CR5' and opens its normally" closed contacts ECRG; Closing of the' contacts ECHT closes a circuit froml the `wire Nil` through' the switchx2'2'i", contacts 5CH-l and the'now'closed contacts 40H5', which were closed'by the previous energization ci relay'iClFt` in the' controll circuit' for the' screen motor l2, to and through the coil' of'a relay'ffM to the wire |62'. Thek energiation ,of the'relay 51V.' closes its normally open contacts BMl and (SM2. Closing,A of. thecontacts Ml completes` a circuit therethroughlandthroughthe now closed contacts 50H2, thereby providing a holding circuit for relay BCR maintaining the latter energizecl after the contacts IlCSll open' upon deen'erg-i-zation of relay |05;l when the' push button switch #Sil is released. Closing" of the contacts 5MB completes a circuit energizing the motor |31 for' the conveyor tt,- itbeing' remembered that the niariuallyoper'able switchesl tltl and H9 are initially closed in the' initial setup of the apparatus thereby completing ai circuit through the shunt elcl |310 and the controll rheostat 229. Hence, the cl'osingof the contacts SM2 now comple't'csthe circuit through: the armature Hilo and the series field |3l'|fb. The closing of the contacts 50H31 has energized the redsign-al lampy 23@ while the openingot the contacts 5CR4 has deen'ergized the green signal lampy 23| thereby indicatingi that the conveyor |236 isv now in operation.

'Jhel conveyor I'Mf is' started lastin the automaticsequenc'e under' control of. the sequence control: relay |CS-anfd the previously mentioned energiza'tionof the-.relay SCR.v Thus', the closing or the contact` |055 completed a circuit from the wire: 5-`| through the normally closed push button switch'232,the contacts |CS5, the normally closed contaotsfta ofv a manually operable push button switchL 233, to and through. the coil of a relay GCR'r toV the `Wire` |552;` Energization of the relay @CR closes its normally open' `contacts 'CRi,

CRZ., iCRSI andA opens its normally closed con-` tacts tCRx't.- rIfhe closing! of the contacts @GRH completes a circuit romf wire #6| through' the switch 232;l new closedlcontactsCRf and sont, the latter' having been closedv by the energization ofrelay 5CH when the conveyor motor |37 was energized,v the circuit being completed' through thercoilpf a `relay. 'IM' to the wire H52. The re# sul'tingf-energization of relay 7M closesl its contacts Mfi andi '|M12. Closingoflthe` contact 'IME completes acircuit through' these' contacts and thel now closed contacts 60H2 in parallel with the contactsilCS' providing a holding circuit for the relay BCR maintaining the latter energized aterfthe contacts FCS openlupon'fdeenergization offrela-y' .ITCS when 4the pushr button switch itil is released.y Closing of. thecontactsv 7M? energiaesl the motori-45 for" theAv conveyor IM by completing-a circuit therethrough for thel armature Mita and series-field |456 since'the manually operable switches andi |8.| were closed in the initialsetup ofthe apparatus; Th'eclosing of the switches [S0-:and: 182| energized the shunt ield M50 for the. `m'o'tor through a circuit including thevrheost'at` 23'4 andhence' the motor |135 is now operation. This c'o'riditio'nA is indicated by lighting" of'y the red signal? lamp :2135; which `'is ener'- gized by closingof theA contacts BCR-3l of relay iiCR,vthegreensigrallariip" 236 having been extinguishedi by thesirnultaneous opening ofV contactstCR of relayfBC-R.

It will loeA apparenttherefore, that by placing the blade |82of the-selectorswitch ati the positionl marked Sequencef and momentarily clepressingthesw'itchy lil'ki'y the apparatus will he automatically sequentially energizedfin the or'cler: stockievel'i'nd'icator and the carriagemotor, conveyor |00, conveyor '52 screen mea-ns 582 conveyor |36, andcon'veyor" fli4l 1t will be observed that due to the presence ofthe'interioclr relays such as ICR, CR) CR; 5GB?, and none of the portions of theapparat'usmay be `energized unless the preceding portion' or" the apparatus ha'salreadyibe'en' placed in operation; The sequential;energizationis, however, rapidly eiiected so ythatV the pushbtton switch` llldoes not have to be maintained depressed for an appreciable length of time. This sequential starting insures against any pile up of material within the feeder, or overflow therefrom, since the exit drives for the apparatus are placed in operation before the conveyor I44 which brings the material to the apparatus. Hence, if the conveyor I or the screen means 58, for example, should fail to start, the motor 145 for the supply conveyor IM cannot be energized.

With the circuits completed as just described, the conveyor |44 carries material to the conveyor |35 Which in turn delivers the material to the screen means 58. The screen 58 by its shaking action both feeds and screens the material, the undersize particles being removed from the apparatus by the conveyor 'I5 while the particles equal to or greater than the minimum size are fed forwardly onto the conveyor It@ which, in turn, delivers the material into the furnace or other receptacle in substantially uniform layers therein due to the reciprocation of the carriage ZI which is automatically effected in a manner about to be described. The indicating means, comprising the lamps 292, 2% and the chains I24, continuously indicate whether or not the stock level, that is the upper surface, of the material within the receptacle or furnace, is at the desired uniform height.

Energization of the control circuit and of the several motors in the manner just described results in movement of the carriage 2l in a forward direction, that is, towards the furnace or receptacle 20. The initial energization of control circuit in the manner described always energizes the motor 49 for eecting movement of the carriage in this direction due to the fact that the forward limit switch U is normally closed and hence the initial energization of the circuit results in energization of the relays IF and 2F, thereby closing the contacts IFS and 2FI. At the same time the contacts ICSB are opened during initial energization, and by the time these contacts close relay IF has opened its contacts IFZ thereby preventing the closing of the circuit for energization of the motor 4S in a manner causing reverse rotation thereof. In the normal operation of the apparatus the carriage with the various conveyors and the screen means thereon moves forwardly until the switch operator 52 on the carriage engages and actuates the forward limit switch 5B thereby opening its normally closed contacts. This deenergizes the relays IF and 2F and also relays IM and DB. The deenergization of relay IF opens its contacts IFI IFS and closes its contacts IF2, while the deenergization of relay .F opens its contacts 2FI. Opening of the contacts iFS and 2FI deenergizes the armature of the shuttle carriage motor 49, thus terminating movement of the carriage in the forward direction, this stopping being assisted by the fact thatthe deenergization of relay DB has closed its .contacts DBI, thereby providing a shunt circuit about the armature 49d of the motor 49 to effect dynamic braking thereof. The deenergization of the relay IM opens its contacts BMI thereby further insuring against continued energization of the armature 49a.

When the push button group start switch 34 was released, after initially starting the apparatus, the relays ICS and ZCS were deenergized. Hence, the contacts ICSG are now closed so that the closing of the contacts IF2 now completes a circuit from the wire ISI through the now closed contacts ICRB, ICSB, contact 237e of a manual switch 221i, contact 238:1. of a manual switch 238, normally closed manual switch 239, to and through the normally closed contacts of the rear limit switch '.iI and thence through the normally closed contacts of the overtravel limit switch 54, through the said closed contacts IFZ, to and through the coils of relays IR and 2R to the power supply line I82. rihe resulting energization of relay IR opens its contacts IRI, thereby preventing inadvertent energization of relays IF and 2F. Energization of relay IR also closes its contacts IRZ in the power circuit for the armature of the motor 48. Energization of the relay 2R closes its normally open contacts 2R! and 2R2. The closing of the contacts 2RI completes a circuit therethrough and through the switch i922 reenergizing the relay iM. Energization of relay IM again closes contacts IM2 thereby energizing relay DB as previously described. Consequently the contacts IMI are again closed and the contacts DBI are opened. Opening of the contacts DBI removes the shunt braking circuit about the armature 49a of the motor 49 while the closing of contacts IMI and ER2 completes the circuit for energization of the armature 49a for rotation in the reverse direction, it being remembered that the contacts IFS and QFI are open. This reversal of direction of rotation of the motor 49 does not affect the operation of the other motors or of the indicating means and hence the carriage simply reverses its direction of movement, thus moving the carriage of feeding apparatus away from the receptacle or furnace 2t, the material being continuously fed thereinto as the conveyor Illil moves backwardly over the top surface thereof.

' When the carriage 2| has reached a position such that the delivery end of the conveyor IBD is adjacent the right-hand side wall of the receptacle or furnace 20, as viewed in Fig. 1, the switch actuator 53 will engage and operate the rear limit switch 5I opening the latter. This deenergizes the relays IR and 2R thus opening the contacts IRE and ZRR in the circuit for the armature 49a of the motor 49. Deenergization of relay 2R also deenergizes relay IM, due to the opening of the contacts ZRI. Deenergization of relay 1M opens its contacts IM2 thus deenergizing relay DB so that the contacts DBI are closed. Also, the contacts IMI are opened.

Hence, electrodynamic braking of the armature is provided and improper energization thereof is prevented.

t will be observed that as soon as the carriage has begun its movement in the rearward direction, the contacts of switch 5D will automatically close since these contacts are normally urged in a closed direction by spring means or the like. Consequently, when the carriage has reached its rearwardmost position, thereby deenergizing the relay IR, as just mentioned, the resulting closing of the contacts IRI again completes the previously described circuit for eifecting energization of relays 1F and 2F so that the motor 49 is again energized to rotate in the direction productive of forward motion of the carriage as previously described. As soon as the carriage again begins to move in this forward direction, the actuator 53 will move from engagement with the switch 5I so that the contacts of the latter close under the action of spring means or the like, not shown, with the result that the circuit is again prepared for proper operation of the motor to move the carriage in a rearward 2l direction after the carriage has reached its for- Wardmost position as described.

In the event it is desired to-cornpletelyI withdraw the conveyor itil from the hood of the furnace or receptacle, this can be effected by manually energizing the carriage motor 49 for rotation in a reverse direction even after the rear limit switch 5I has been opened. This is rendered possible through holding push button switch itt depressed. This opens the circuit for relay I CRl through contact Etta of switch |88 thus releasing the holding circuits for the several motors. As a result the contacts ICRS are opened so that the carriage motor t is not energized for rotation in a forward direction. Actuation of switch ISB also moves its contact |3813 to circuit closing position, thus completing a circuit from wire |61 through a wire 2de to and through contact web, through switch 5d, contacts IFE, and relay coils IR and 2Rl tothe wire |82. The energization of relays IR. and 2R complete the above described circuits for eecting energization of the carriage motor I9 to move thecarriage to the rear. This movement continues until the switch actuator 5t engages and operates switch 5d thus opening the contacts thereofV and stopping the motor, the switch lid being so positioned that it is not operated until the carriage has been completely removed from the furnace hood. The carriage may be again moved forwardly by releasing the push button switch |825V and again operating the start switch |84 or switch |39.

In the event that the indicating means such as the lights 2M, tti-i indicate voids in the tcp surface of the material during the automatic reciprocation of the carriage, the carriage may be held without movement by depressing the manually operable push button switch |92. This deenergizes the relay iM and hence relay DB, so

that the contacts IMi are opened and the contacts DB5 are closed, thereby deenergizing and stopping the armature of the carriage motor llt. The relays IF and 2F, or IR and 2R, whichever are energized in accordance with the direction ofinovement of the carriage before operation of switch |52, are not affected by operation of the push button switch |92. Moreover, the relayv i CR is not deenergized and consequently the carriage will remain stationary as long as the push button |92 is held depressed without interrupting the operation of the several conveyors and of the screen means with the result that material continues to be delivered to the furnace or receptacle without reciprocation of the carriage. When the push button switch |92 is released, the relays IM and DB are again energized and the carriage will resume its operation in the direction in which it was moving before operation of the switch |92.

In the event the carriage is moving in a forward direction and it is desired to reverse the latter before it reaches its extreme position operating the corresponding limit switch 5B, the manually operable push button switch I9 I-is depressed momentarily. Operation of this switch opens the circuit therethrough thus deenergizing relays IF, 2F, IM and IDB so that the carriage motor i9 is stopped. However, relay ICR remains energized holding-contacts ICRZi` closed and, since relay I CS was deenergized when the start push button It@ was released, contacts ICSE are closed. Therefore, deenergization of the relay IF closes its contacts IFE thereby completing a circuit from the-wire ItIthrough-contacts ICES, ICSB, 231e, 238a, 239, 5I, 5d, |132 toand throughv the relay coils IR and 2R energizingfthe'serelays. nergizat'ion of relays IR'andfZR completes the previously described circuits energizing motor t9V in the reversedirection and the'rcarriage movement is therefore reversed. Since the relay ICR remains energized, the several conveyors and'A the screen means remain in operation as the carriage moves rearwardly untilthe limit-switch 5I is actuated effecting automatic return of4 the carriage or until one of the manualv switchesZt-, 33t, or 23e is operated?. If none of the switches 23T, 238y or 239 be actuated, thencarriagefmoves rearwardly until theactuator 52 thereon engages and operates switch# 5 Iv whereuponn the switch and relay operations are-as'ab'ove described terminating the rearward movement and `initiating the forward movement.l vThe appara-tus vwillfthen continue in automatic'operationV under control' of the forward and rearl-imit switches until one of the manual switches-isag-ainop'erated.

In the event the carriageis'l moving a rearward direction, that is totheri'ght'as viewed-in the drawings, and it Ybe desiredfto reverseV the direction of movement of the carriagey so as to cause the latter` to move in'l the forward direction before the carriage reaches the position for operation of the limit switchv 5|,'this` reversal of direction of motion may be effected by momentarily manually depressing the" forward push button switch 239'. @poration-'of this'switchopens the circuit forthe relaysrIR", 2R', IM and DBl so that the carriage m'otorid'isstopped. However, relay I CR remains energized holding-'contacts ICR? closed- Thereforeythe'closing'of contacts IRI as the resultl of= deenergization-of'relay' IR completesy a circuit eXtendingffrom' the Vwire IGI through the contacts' I-CRZ, wire' IStfswitches ISI, 5t, conta-cts IR|- to the wire |62 throughithe-coils of the relays Il? and-12F.- Energizationsof the relays IF and 2F-completes theA circuits previously mentioned for energizing the'lrelays` IM, DB and completes the circuit through" the armature ofthe motordglin aimanner-effecting| rotation of the latter in' adirection causing forward motion of thecarriage. The carriage will' then move in this newv direction until1the actuator-52 engages and operates switch-5t astabovede'- scribed'.

The actuation of either-switch I 9| or' 239` to reverse theI movement of' thelcarriage4 does not interrupt the operation ot the lvarious conveyors and the screen means sincey the control' relay ICR remains energizedthus maintaining the circuits for the conveyors andsereen means energized through the' above described relay contacts. Hence,- if the indicating lights 2HE, 2&3 evidence that therel isa Vvoid or `voids in the surface of the material: in the furnacethe--carriage mayv bel immediately returned over that portion of thefurnace to supply additional material thereto.l Sincethesvvitch` t9 I mayv beactuated at anyv point in the forward" movement of' the carriage; andthe switch-239` may heeetuated at any point inthe rear-Ward movement of the carriage, thecarriage can-be repeatedly moved over a givenA areaA in" the furnace` by-alter natev operation of theseswitchesl andwithout the necessity of having the: carriage operate either limit' switch 5t" or- 55| a The control circuit 'fon the carriage motor is also provided with*v two manually operable stop switches E and |36 ofthe-push button type; Operation of either of these stop buttons will stop thel motion-- of thecarriage; regardless: of its direction of# movement; fand also deenergize the various vdrive motors for the conveyors and the screen means, since the operation of either the stop buttons 185, |86 breaks the circuit for the relay ICR. Upon release of the actuated stop switch, the circuits are not restored, since the sequence control relays |CS, 2CS do not remain energized after their group start button |84 is released. Starting 0f the apparatus may, however, be again eifected by operation of the group start button |84 and the apparatus will resume operation in the manner previously described. The carriage may be independently started, however, by operation of either of its push button type start switches 23'1, 238, thereby closing a circuit through the upper contacts thereof 23127, 238i), energizing the relay ICR. It will be observed that operation of either of these start switches 23? or 238 opens the circuit through the lower contacts 23`1a or 238e, which control the energization of the

relays

1R and 2R `and hence the carriage will resume movement in a forward direction regardless of its Vdirection of movement prior to stopping.

The indicating means is not deenergized by the previously mentioned stopping or changing the direction of movement of the carriage by operation of the manual switches such as 135, 186, |88, |99, |91, or 239 since the contacts 2M| provide a holding circuit for relay 2M which is independent of the other relays in the circuit. The indicating means may, however, be deenergized by operation of one or the other of the manual push button stop switches 19'1 or |98 in the energizing circuit of relay 2M. The indicating means may again be energized by operation of the group start switch |84 or may be started independently of the remaining portions of the apparatus by operation of either of the manually operated start buttons 24| or 242, either of which is effective to close a circuit energizing the relay 2M.

If the carriage has been individually started by operation of either of the manually operable switches 23'1 or 238, the conveyors and screen means may be individually jogged or may be manually started in their sequential order by sequentially operating the individual start switches associated therewith, that is by operating the start switches 243, 244, 245, 243, and 241' in that sequential order. This follows from the fact that energization of the relay ICR in the carriage control circuit has closed the contacts ICRG so that operation of the manual switch 243, resulting in energization of the relay ZCR and hence closing of the contacts 2CR1, energizes relay 3M controlling operation of the motor lill and completion of the holding circuit for relay ZCR. Likewise, the energiz'ation of relay ZCR closes the contacts 2CR5 so that operation of the switch 244 energizes relay SCR and, in turn, relay 4M, thus starting the motor '16, Also, energization of relay BCR closes the contacts 3CR5 so that operation of the switch 245 energizes relay 4CR, and hence relay 5M, starting the motor '12 for the screen means. The energization of the relay 4CR closes the contacts 4CR5 so that operation of the switch 246 now energizes Arelay SCR, and hence relay 8M, starting the motor 13'1. Finally, the energization of relay SCR closes the contacts CR5 thereof so that operation of the switch 241' effects energization of relays BCR and iM starting the motor 145.

For safety purposes an additional push button switch, in the control circuit, is mounted near each individual drive motor. These switches are of the type having a ferrule or collar settable to hold the switch in a partially depressed position. If this collar be set so thatthe switch is in its On position, the several motors operate as previously described. If, however, the collar of a switch be set in Safe position, the corresponding switch is partially depressed, as indicated by broken lines in Fig. 14, so that the circuits therethrough are opened and the operation cannot be sequentially eiected as previously described. However, each individual motor, except the carriage motor, may then be jogged by further depression of the push button switch having such a collar while the collar is in the Safe position. Jogging of the carriage motor can be elfected, as previously described, by switches other than the safety switch. These safety switches are the switches previously designated and referred to as 1.81, 214, 219, 224, 228 and 233.

It will be observed that the switch 18?, in the carriage motor control circuit, is in the nature of a simple stop switch, provided with a settable collar to hold it in its depressed or Safe position, while each of the other switches comprise two sets of contacts, one of which opens a circuit when the other closes a circuit. Thus, the switch 214 in the control circuit of motor 19| has its contact 214m moved to open position when the switch is operated. This contact is maintained in the open position, indicated by broken lines in Fig. 14, when the ferrule or collar is operated and in which position the upper contact 2| 4b does not quite close the circuit through the relay 3M. However, with the switch 214 in its Safe position, that is with the contact 2|4a in its broken line position, the switch 2id may be further depressed, thus moving the contact 21419 into circuit closing relationship thereby energizing relay 3M so that the contacts SM2 are closed thus energizing the motor 10|.

It will be observed, however, that, since the contact 214e is in open position when switch 214 is thus actuated, the relay 2CR cannot be energized and hence the next motor in sequence, namely, motor 16, is not prepared for energization. Moreover, the motor |El1 does not remain in operation when the switch 214 is released since the contact 214D then moves to open position. This is true whether the contact Zilla returns to either its Safe position, if the collar remains in its previous position, or to the circuit closing position shown in full lines in the drawing, if the collar has been restored permitting such operaion. In other words, operation of the switch 2 i4 can only be used for jogging the motor |91 for operation of that individual motor and that only so long as the switch is manually held depressed. Moreover, since the circuit to the relay ZCR is opened whenever the contact 2Mo, is depressed, each of the other drive motors following the motor i1 in the previously mentioned sequential order, is deenergized whenever the switch 2id is operated. Each of the

other switches

219, 224, 228 and 233 likewise has an upper contact 2131i, 22421, 22813 and 23327, respectively, which operates in conjunction with the lower contact of the corresponding switch to control the individual associated motors 16, '12, 13? and |45, respectively, 1n the same manner as described for the motor |01.

With the selector switch 182 positioned to engage the terminal marked Manual any drive 1n the apparatus may be started or stopped indi- 27 simultaneous with the energization of the carriage motor. However, if the carriage motor or any of the other drive motors should fail to be energized this will prevent energization of all the other drive motors following the non-operating motor in the sequential order.

When these circuits for the various drive motors have been established by operation of switch |812, the material is delivered from a source of supply by means of the conveyor 41| to the conveyor |36 which in turn delivers the material to screen 58. The material passing over the screen is delivered to the conveyor N3D and is charged by the latter into the furnace or receptacle 20, the undersize material which passes through the screen being removed by the conveyor 15. The delivery of the material to the receptacle is normally effected by continuous reciprocation of the delivery end of the conveyor 10|] over the top of the furnace or receptacle due to the reciprocating movement of the carriage 2l, the direction of movement of the latter being automatically reversed at positions corresponding with positions of the delivery end of the conveyor adjacent opposite side walls of the furnace 2B or other receptacle being charged. During this movement, the stock level indicating means continuously indicates whether or not the top surface or stock level of the material Within the receptacle or furnace is at a uniform predetermined height.

In the event one or more of the indicating lamps such as 292, 203 is extinguished, this indicates that a void is present in the stock level or surface of the material in the receptacle 2i) at the region then being traversed by the chain |24 corresponding with the extinguished indicating lamp. If this void is not corrected by the automatic operation of the carriage, the latter may be held at a given position in its reciprocation without interrupting the delivery of the material by manually operating the hold push button |92. Correction for voids may also be effected by reversing the direction of movement of the carriage at any point in its cycle of reciprocation, by operating the proper reversing switch |9| or 239, without terminating delivery of the material.

It will be further observed that in the event one portion of the mechanism should stop or be stopped for any reason, each of the succeeding drive motors of the apparatus in the sequential order of starting will be stopped automatically. This prevents piling up of the material either Within the furnace, or other receptacle being charged, or upon the feeding apparatus. Thus, if the conveyor |66 should stop or be stopped for any reason, the conveyors 15, |36 and |44 Would likewise stop, as would the screen means 58, so that no more material would be supplied to the feeding apparatus nor would the material then present in the apparatus be delivered to the furnace. Likewise, if the screen means 58 or the conveyor 'l5 which removes the undersize particles from the apparatus, should stop or be stopped, the conveyors |44 and 36 supplying additional material would likewise stop. Stopping of the carriage, other than by operation of switch 92, will stop each of the conveyors and the screen means. Provision is also made in the machine for manual operation of each of the separate portions thereof.

It Will thus be seen that the apparatus of this invention effects feeding of discrete bodies of material to a receptacle, such as a shaft furnace or thelike, in a manner providing a substantially uniform stock line or top surface of the material Within the receptacle. This feeding is effected in a. manner such that any voids occurring in the stock line or top surface of the material in the receptacle charged may be immediately indicated and corrected, a feature which is of paramount importance where the receptacle charged is in the form of a shaft furnace or the like from which material is Withdrawn adjacent the bottom and in Which it is desired that a uniform bed or stock of material be maintained so that uniform heating will occur therethrough. Furthermore, the apparatus provides for the said feeding operations to be effected with a minimum of breaking stresses upon the bodies of the material, provision also being made for automatically removing bodies smaller than a predetermined minimum size, thereby insuring that the bodies charged to the furnace or other receptacle are oi a size equal to or greater than a predetermined minimum.

While the apparatus has been described in considerable detail with respect to use in charging a shaft furnace, rectangular in cross-section, it will be apparent that the apparatus may also be employed for charging bins or other receptacles Where similar problems are involved. Furthermore, modifications and variations in the construction of the apparatus may be effected by those skilled in the art Without departing from the inventive concept here disclosed. Therefore the illustrations and descriptions are intended only for the purposes of disclosing a practical embodiment of the invention in its present preferred form and are not to be construed as limitations thereon.

Having thus described the invention, we claim:

l. An apparatus of the character described for use in charging material in the form of discrete bodies into a receptacle, the said apparatus comprising vibratile screen means the openings of which are such as to permit passage therethrough `of the bodies of the material having a size less than a predetermined size, conveyor means for delivering material from a source of supply to said screen means in a substantially uniform stream, means supporting said screen means adjacent the rear thereof in a manner permitting adjustment of the horizontal and vertical components of the vibratory motion imparted to the bodies of the material thereon, conveyor mea-ns having a substantially planar surface extending substantially horizontally with a portion adjacent the discharge of said screen means to receive the material passing thereover, and means connected with the last-mentioned conveyor means for effecting reciprocating movement of the delivery end thereof over the top of the receptacle, Whereby only bodies of material having a size greater than a predetermined minimum are charged into said receptacle and said charged material is distributed substantially uniformly throughout the cross-sectional area of the receptacle.

2. An apparatus as dened in claim 1 wherein the said screen means and the said lastmentioned conveyor means extend in the same direction and the Width of said screen means adjacent its point of discharge to the said lastmentioned conveyor means is substantially equal to the Width of the latter so that the bodies of material are delivered to said last-mentioned conveyor means and from the latter to said receptacle with a substantially uniform transverse distribution.

3. An apparatus of the character described for use in charging material in the form of dis-