US2908062A

US2908062A - Brick press batch distributor

Info

Publication number: US2908062A
Application number: US499787A
Authority: US
Inventors: Fred O Schob
Original assignee: Harbison Walker Refractories Co
Current assignee: Harbison Walker Refractories Co
Priority date: 1955-04-07
Filing date: 1955-04-07
Publication date: 1959-10-13
Anticipated expiration: 1976-10-13

Description

F. O.`SCHOB BRICK PRESS BATCH DISTRIBUTOR Oct.A 13, 1959 Filed April '7. 1955 l :l n...

.I Ff I I INVENTOR.

Fve'a O. Sel/0e @we am United States Patent C BRICK PRESS BATCH DISTRIBUTOR Fred O. `Schob, Pittsburgh, Pa., assignor to Harbison- Walker Refractories Company, Pittsburgh, Pa., a ,corporation of Pennsylvania Application April 7, 1955, Serial No. 499,787

3 Claims. (Cl. 2S.-103) This invention relates to brick presses for `manufacturing refractory bricks, and more particularly to the feeding of batch material'to the presses.

The Well-known Boyd toggle press is an exampleof the kind of press to which this invention applies, but the invention is not limited thereto but is applicable also to other presses whichv form bricks from a granular batch. Many of the important properties of bricks `made in Vsuch presses are governed by their bulk density, the control of which t will depend on the success in feeding the same weight of uniformly mixed material to each mold box at each pressing. Refractory bricks are made of refractory grains of graded sizes, together with water for tempering or lubrication. No other bond may be needed in order to give the bricks enough strength to be handled through drying and ring. In other cases, such bonds as starch, lime or sulphite Waste liquor may be used. In any case, however, the batch is dilicult to handle in ordinary equipment, because it is moist enough to be resistant to easy flowing.

Present brick press charging devices require the semidry granular batch to ow laterally from the feed pipes into ythe charging box, because the pipes have to be placed 'near the opposite sidesV of the charger due to the central location of the pitman arm that operates the toggle. During this lateral flow of the batch, segregation of the various particles occurs and causes trouble. Thus, frequently the largest particles ilow forward into the front end of the charging box so that the finished brick will be different in composition or structure/from one end to the other. Such brick often haveto be scrapped.v Furthermore, this dependence on material flow by gravity often results in bricks which are poorly lled out. In a multiple mold set up, the several bricks may have diiferent weights, due to unequal charging. The lighter bricks will be unsatisfactory because high density is almost universally sought for in such products. Moreover, in refractory/batches of certain types; for example, a lire claybatch made of flint clay and plastic clay, the rolling of particles leads to an unwanted segregation. The plasticr clay iines tend to roll up into small balls that are objectionable in the product and that prevent uniform distribution of the plastic clay which is relied upon for developing strong bonding.

In an attempt to correct this situation, attempts have been made to agitate or mix upvthe segregated batch after it enters the charger. These atteni'pts'y have not been successful, however, because the mixingdevices havefmerely churned around in the batch and cut paths through it without redistributing the fine and coarse particles throughout the charger to produce a uniformmix.

It is among the objects of this invention to provide blick press feeding apparatus vwhich prevents objectionable segregationpof the batch from occurring in the first place, and which Will not pack the batch into a hard mass in distributing the batch evenly throughout the charger. In accordance with thisinventiom a charging box having an open top and bot/tom is movable forward 'from a batch-receiving position to a discharging position over ICC the molding cavity of a brick press. A feed hopper empties into the box `when it is in its rear position, and a distributing housing on the hopper has an open bottom that empties into the hopper. The top of this housing has an inlet opening near one side, to which an upright conduit is connected for delivering batch material to the housing. Journaled in the housing is a central vertical shaft, from which a distributingY arm extends laterally. This arm, preferably, includes vertical ngers spaced lengthwise of it, and the shaft is rotated to sweep the arm in a circular path around the inside of the housing in order to remove batch material from beneath the inlet opening as it enters the housing and to distribute it throughout the housing. It is highly desirable that the shaft-rotating means be formed to stall when the resistance encountered by the arm exceeds a predetermined value. This will prevent the arm from packing the batch in the housing.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which Fig. l is a fragmentary vertical section through the upper part of a brick press;

Fig. 2 is an enlarged plan viewrof my feeding apparatusA alone; and i Fig. 3 is a View of the rear end of the feeding apparatus. Referring to Fig. 1 of the drawings, a brick press frame 1 is provided near its front with a molding cavity 2 in which bricks 3 are pressed between upper and lower dies 4 and 5. The upper `die is reciprocated vertically byva cross head 7 slidably mounted in guides 8 'at opposite sides of the frame. The cross head is moved up and'dow by' toggle links 9 and 10 pivotally connected to the front end of a pitman arm 12 that extends'back throughthe center of the machine to a crank pin 13 carriedfby a large gear 14. Synchronized with the movements of the dies is a charger that is slidably mounted on'a table `1,6 directly behind the mold cavity. Thefro'nt half ofthe charger'is in the form of abox 17 that has an open top and bottom. The rear half of the charger includes a horizontal plate A18 on a level with the top ofthe box.v Pivotally mounted-be'- neath this plate is the front end of aV rod `i9 which extends back into an arm 20 that is, swung b'ackf and forth lin a Well-known manner to reciprocate the charger over'the table. The charging box receives a charge brickmaking material or batch in its rear positon, and then is'moved forward when the upper die is raised. In its forward position the box registers with the mold cavity and thev material in the charger drops into the cavity.v When a plurality of bricks are being'made at the same time, 'the charging b ox and molding cavity are provided with "partitions,` as is Well-known. l Y Y Itis a feature-of this invention that every time the-charging box isV retracted it is filled witha uniform=mixture of granular material, in which there is' no objectionable segrev gation of coarse and fine particles. Accordingly,`a short hopper 22 is rigidly mounted in the frame in any `suitable manner in a location directly above the'charg'ing' box 17 when the latter is in its rear or-retra'cted position; 'The hopper has an open bottom the samesiZe as the top of arcuate portion that Vprojects behind fthe, h purpose thatwillsoon become clear. 9 l

titer' ag vIn order to deliver the semi-dry batch of brick-making material to this feeding apparatus, the conduit 25 through which the material is fed by gravity has to be locatedatone side of pitman arm 12. .The conduit Vshould be asnv straight and vertical as possible Accordingly, as shown in Fig. K 21, the top of distributinghousing 2.3 is provided nearY one side wi'tih .apinlet .opening 26 communicating with the Vlower endV of the conduit. Mounted on the housing beside the conduit and beneath the pitman arm is a motor 27 that drives a short vertical shaft 28 projecting down -in-to therenter of.1thehousing. V'.[Y'he .lower end..of this shaft supports vaJplll-rality:of .radial arms, each of whichis longgenough to extend across inlet .opening 26. The purpose ofthese arms is to sweep or carry the incoming material aroundztotheotherparts of .the housing in orderi-tofdi'stribute: the Vbatch uniformly therein. Thi-s distribution-.occurs als-.the .material renters Vthe housing from the .conduitand-before any .segregation .of coarse and ne particlestcan take ,;place. Y

rEachdistributing-.ar-m,cpreferably, is formed from a horizontal :bar lldocatednear 'the topofthe housing and frseveral-iingers lextendingfdownward from it. These-fingers act similarly tothe tines .of a rake and Athus rake the .hatch aroundinthe housing. They are long enoughto nearly touch the bottom ofthe projecting arcuate :portion-lof l.the housing. vThe V74lingers are .spaced apart Fto .keep V.the material from ypacking AbetweenV them, but most suitably they are disposed at .an obl-ique angle to the-longitudinal faxesof the bars in order to exert more of a pushing action against the batch. Some ofthe iingersfare-reversed relativeto otherstov help keep the batch from packing at the centerof the housing.

.The .moto/1" rotates-.the `distributing arms as -long as V.the batch in the housing is fairly loose, but the motor isdesigned-.to .stalllrorstopf as soon lasthe housing becomes so full that Athe materialbegin to pack. A desirable type Y of motorfor this purpose is apneumaticmotor, to which airis .delivered at a predetermined pressure through a pressureregulator 33 and'hose 34 as'show-nin Fig. 3. vAs soont astthe-.forceexerted against the arms .by the .resistance ofthe material in thehousing equals the air `pressure that operates .the motor, the wmotor will ystrop without being damaged. Consequently, the batch will not be Ypacked into 4a .solid mass. inthe housing,l butfwill remain-relatively loose. Y

Assuming that the `feed conduit, distributing (housing, hopper yand charging box'are allgfull of the desired batch, the charger is moved forward to -ll .the mold cavity and then=is retracted. As soon as the-:empty charging box lis pulled back beneath the hopper, the batch in the. hopper fills .the box, :the material in the housing `falls straight down .-into the hopper, the motor-starts 'to rotate .the `distributorarms, ya'nllthe material in the feed conduit :starts tomoveidowninto thesdistributillg housing. As'fastfas thefmateriahenters the :housing the distributing arms carryit'around and distribute-it uniformly throughout-the housingibefore segregationeoan occur. As they housing becomes'lledinsthisnnanner, resistance to trotation :of the arms fwill increaseuntil they and the motorV stall. VThe armswill-then.remain motionless until'thezcharging box is moved forward and emptied and returned for va new v charge. Y r

.According tothe provisions fof' the patent .statuten-I have ,explained the principle ofnnyinvention and have invention may.bepracticedzotherwise than as specically illustrated A:and described.

Igcvlaim: s Y, Q 1. .Feeding -apparatus for use with la' brickpresspro- Vv'dedjwithIa molding-vcavityQthe feeding apparatus-com-V "a 'distributing'housingon the hoppenihaving-an open bottom emptying into the hopper, the top of the housing hav- 'ing `an inlet opening near one side, an upright conduit'connected with said opening forfdelivering batch material to the housing, a central vertical shaft journaled in the housrotating :means includes a .pneumatic motor `and Vran :air Y pressure 'reducer lconnected with` the inlet of fthe motor, whereby the motor Will stall whenever the resistance-to movement-fof said arm equals the sairpressure delivered to the motor by said reducer.

2. Feeding apparatus'foruse with abrick press provided with a molding cavity, the feeding apparatuscomprising a horizontally reciprocable charging box having an open top andbottom and movable .forward from ya Ibatch-receivingposition .toa discharging positionzover saidcavity, a hopper emptying into .the rboit in its rear: position,;a distri-butinghousing on the hopper having an open bottom emptying into theY hopper, the top. of the .housing having an `inlet opening near one side, anupright conduit con-j nected with said opening `for delivering batch materiall .tothe housing, a central vertical shaft journaled gin the housing,..a ,distributor arm extendinglaterally awayfrom the shaft, a'motor for rotating theshaft to sweep. thearmY in .a circularl horizontal path around the inside ofthe housing ,toA remove batch material from beneath V.said inlet opening Y, and .distribute .it throughout-the housing, and. means foroperating vthe Amotor withi-Va predetermined.

torque, whereby Vthe motor willbe stalled .when the resist-- y ance encountered by said .arm exceeds said torque.

3'. Feeding 4apparatus for use with .a brick press-pro. vided with .amolding cavity, the feeding apparatus Vcomprising. ahorizontally reciprocable charging box having an open'top and bottom and movable forward froma batch-receiving .position-to a discharging positionover said cavity/a `hopper emptying `into the. boX .in `its..rear position,the side walls of the hopper being substantially vertical, .a distributing housing onthe .hopper havingan openbottomsubstantially the samesize as the. opening .in top of. the hopper and -emptying .into the hopper, the ftop ofthe housing havingan inlet opening'near-one .sideld-V Y rectly ,above'the hopper, Van ,uprightconduit connected prising a horizontally reciprocable charging boxhaving an. open `top and bottom and -movable forward from@VV batch-receiving positionvtoradischarging.position oversaidY cavity, a hopper emptying ntotheV boxinitarear position,

with'fsaidnopening for delivering batchrrnaterial to. the housing, l.a central vertical .shaft journaledin .the housing, a distributingarm-extending laterally away. from the shaft, and. means -fonrotating V.the shaft to `sweep `the arm ina circularhorizontal. path around the inside ofthehousing toremove batch material Afrom :beneath .said inlet opening and `distribute .it-throughout the housing ontopvof, th

batchmaterial -in the v.underlying hopper.

.ReferencesCiteil inthe leof this patent- UNITED-STATES 1PA-TENTSV