US2328402A - Mineral jig - Google Patents

Description

L. E. TUTHILL Aug. 31, 1943.

MINERAL J IG 4 5 Sheets-Sheet 1 Filed Dec. 18, 1940 L. E. TUTHILL Aug. 31, 1943.

MINERAL JIG Filed Dec. 1s, 1940 5 Sheets-Sheet 2 FIG] 7 7W.. -2 L 3m I H5v s -Moo 24 Rm n v\ O, N w. Y. .MW rm y@ A G m. m MF 1E. ||.^nvv0.l\\ E ..-Ta lm A3 L l u, la L mmol 3 L 5 1#4M` IM l 3 3 4w3 I 5 8. 3 4 l 3 :.0u 5 6 G. \4W l F 9 F: W4 6 5 l, 5 52 64 .2 5

Aug. 31, 1943-. 1 E. TUTHILL 2,328,402

' MINERAL JIG Filed neo. 18, 1940 5 sheets-sheet 4 INVENTOR LESLIE E. Tu H/LL ATTORNEYS Aug. 31, 1943. L/E. www.

MINERAL JIG Filed Dec. 18, 1940 5 Sheets-Sheet 5 stances of value or not. `mass oflmaterial isconveyedby water.V solids contained "in the HuidVhaVingV" Patented Aug. 31, 1943 Leslies. Tuthili, seattle, wash., assigner te L. E; y' Tuthill, Inc., Seattle, `Wash. l j

Application December 18, 1940, seriaiuas'zasri 4 claims. (ci. zoe-455) 1p My invention relates to improvements in a mineral jig of the type used in dressing ore to separate heavy materialssuch as relatively large size mineral particles from lighter materials such as small particles of mineral or gangue by agitating and stratifying such materials inthe presence of water or other fluids, e

It is well known that the art of`miner`al reenA covery requires careful, accuratetreatment of `mineral bearing materials in order that the maximum recovery can "be made in the ore milling operation. The place ofthe mineral jig in the circuits and methods employed in recoveringr i valuable materials "verts in this eld. mineral jig, however,

is readily recognized' by ex- The basic principles `of a" require renem'ent and im- 1 usually metal shot'of a site and weight which may bevaried to determine the size and nature of "particles" tirati are to be passed downwardly and berecovercd inthe jig asa mineral concentrate. The volume ofdownward flow is regulated by varying theidepth of the'jig` bed.

In operation, `thefjig bed, having iluid borne particles flowing thereover, is pulsated or raised periodically to 'eiect stratification and to momentarilyopen or make permeable the jig bed to permit ore particles having `greater specific gravity than the `material forming the jig bed `to passtherethrough As' the periodic pulsaprovement to permit their usemore widely to treat complex ores and treat larger quantities of material with agiven machine operating power output. l l i Jigs are ordinarily employed in mill circuits of both the closed and open type andare often used between an ore Crusher and the classiiler` where the materials being treated are sorted as to size. The primary purpose of a mineral jig is to effect an initia1 recovery of mineral values inthe circuit which need `not thenbe further handled through other stagesuand `machines of recovery.` An important use of the jig is in re-` covering gold particles `from`ithe uid discharge oi the ore crusher. Such adischarge includes gold particles of vall sizes;` sulphides,` 4quartz particlesand other metallic crunch-metallic sub- They accumulation or y l arious rates of settling because of theirdiitering specific gravities, present diiilcult separation problems -to the mill operator.

However, the employment of these diiierentialsisl'essential in= jig treating ore in order to accomplish the desired separation. In millsiemploying `both the open or closed grinding circuit, oreisigrouridor `crushed and passed to a jig through suitableconduit` means and in the presence of water.` This crushed 'orebearing fluid is introduced of a. launder or trough and is caused to owgover the "jig bed where it `is` activated `to produce stratification of thesolids according to sise `and specific gravity. i i i The jig bed is usually mounted ina frame having `a lower screen which may be `dividedl on its upper face into compartments. On the upper face of the screen and inthe compertinents,4 if theybe used, is placed a quantity '-otbedding,

VThese f tionyof thejig bed `ceases `and thevindividuall members of the jig bed close together through the eiect` of gravity, `particles lighter than the `.jig bed'are thus trapped above it and are carried away by the lateral' flowiof iluid across "the jig :Thelparticles which pass Adown through or permeate the bedding of the jig are collected in Va, lower ltank or hutch.` The material thus concentrated `is substantially purevalue suitable to be immediately reduced `to fa; marketable -productin `the form' of ingots 'or even `as metallic granular.concentrate.y `1 j l j 'Itisw'ell known that jigsare'useful to recover Y free gold which need not be treated in thefull i milling circuit and isqeasilyrrecovered. In `addition; jigs are useful to simplify the flotation operation, improve the operation ofthe lters and thickeners,4 eliminate amalgamation plates aswell as for countless other reasons. l

The jigs commonly in use heretofore have empieyed the principle ef nuid egualmente activate the jig bed;4 In accordance with these `principles a heavy periodic flow of water is applied to the under side of the jig bed. This raises the jig shot bed and separates the bedding lelements to permit the material being concentrated to settle l or permeate through the bed.` During uasubsetolthe jig by means V quent quiescent period the bedding returns `to rest iniits support. l j Such periodic flow of water has been produced rby tiltingthe jig ,frame to andfro to causethe enclosed uid to` surge from end tofend under the jig bed. Anotherform of. periodic agitation is that resulting fromtliefuse of diaphragm pistons in falwall of the jig hutch, the diaphragm being agitated' from` without `by Various types of ,mechanisms` Walking beams have, been employed `to `operate the diaphragmfas also. have various other types ofglinkage arrangements.

Thel result of these arrangements is to impart asurge or agitationwhich tends to rise rapidly,V

illustration,

' of illustration,

y takenon line 6-6'of Figure 3,

attain a peak, and then fall rapidly without any sustained peak. kThis is undesirable because of the extremely short period afforded for concentrates to pass thru the jig bed.

A prolonged suspension of the jig bed will permit a greater downward flow of materials sought to be concentrated and thus is more efficient concentration possible. It hasA been an important object of this invention to lprovide a jig having a cycle of operation in whichlthe suspension period of the jig bed is prolonged to keep the shot bed open or permeable as long as possible.

Another object of my invention has been the incorporation of my novel prolonged suspension period principle into a jig without adding to the complexity of construction or operation of the jig. A further object of the invention has been the employment of a tilting beam or double bell crank actuator mechanism having incorporated provision in a' jig of peak sustaining means operi able in conjunction with 'i the pulsator means employed,

rStill a further object of my invention has been to provide a rifflevtrough suspending and agitating mechanism for jigs 'whichis resilientlyniountedand positively agitated to aid and en stage of an agitation cycle, in which a charge of fluid is drawn into the Yvalved inlet chamber,

Figure 9 is a similar sectional View of a secondary stage in the agitation cycle at which point the valve chamber has been completely filled with a iiuid charge,

Figure l is a similar View, further disclosing a subsequent stage of the agitation cycle and more it specifically shows the relation of the elements of construction as the valved inlet ,chamber is being discharged of its contained uuid, i

`Figure li illustrates the final stage of the agitation cycle with the inlet chamber about to be .closed and the displacement diaphragm about to start its function,

Figure l2 is a perspective view of a drive shaft and crank employed in my device,

Figure i3 is a perspective view of a slide block. used' in connection with the walking beam of my device, j o o Figure la is a perspective view of the bell cranl actuator which o erates the pulsator mechanism-oi my mineral jig; c

Figure l isa perspective View of the diaphragm plate which attaches to the arm of a bell crank in my jig, v

Figures loand 17y are enlarged fragmentary views of the lever arms, detailing the operation of the slide blo-ck andthe manner in which the leverage applied tothe walking beam, is changed throughout a rotation of the crank.

Figure 18 isa vertical sectional ,view through hance particle stratication'in the cross: flowingA fluid being treated in the jig; .i

Other and more specific objects and advan v tages` of the invention will become apparent' during-the-course of a reading of the following specification andl a study of the accompanying drawingsY in which I present a,` preferred embodi-r ment of myrinventio'nft will be' understood for the purposes of the descriptionrof this invention; y that while I have described its application to the recoveryvof 'gold'particles from fluid carrying crushedzore, I'do not wislito be limited inthe scope of myinvention to such installations. The

uses of such a device are many and varied and only limited by the ingenuity of designers of ore dressingplants.

In the drawings, l i f Figurev l is a side elevation of my mineral jig with'portionsbroken away for convenience ofV Figure 2 is a frontv elevational 'View fof my jig 'also with portionsbroken away for convenience Figure 3 is a plan view overflow launder, 4

Figure 4 is a fragmentary sectional view taken onr line lle-1 of' Figure 3, and illustrating the general arrangement of the jig bed vand an agitating baffle employed' in the combination,

vligure, '5 is a crosssectional view through the launder as though taken online 55 of Figure 3,

' V`Figurel Gis a fragmentary cross-'sectional view Figure 'I is'across-section ofthe agitator shaft u of the baffle take'non line 1 1 tof Figure 5,

Figure 8 is a. sectional rView illustrating the pulsating mechanism aslpositioned inan initial x of the jig showing asso- 'n elated therewith a feed launder and a -tailing or ;r have employed the invention, v

a modiiied form of agitation mechanism in which general principles of my -Figure 19 is -a vertical sectional View of the same nature as the -showing' of Figure i8 but illustrating a further modified form of my invention,l v

Figure 20 is a fragmentary elevational view of an adjustment device employed in a modied -v form of my invention,

lFigure 2l is a vertical sectional viewof a modi-- fled device according to the principles of my in- Y lvention and illustrating the mechanism adjusted by, the arrangement ofv Figure 20, and

Figure ,22 illustratesastill further form which my vinvention may' take in which a wide range of operating characteristics for the agitation mechanism may be obtained.

Referring to the drawings, the numeral 2G desT ignates a hutchhaving lower converging sides or walls formingA a settling chamber 2'! which is substantially of inverted'conical shape and which terminates in spout 22 on the lower pointed end.

A cleanout valve 23 is fitted in the spout 22 and is provided with agate 24 which may be locked onoccasion.

Rising above the sloping walls of the hutch and disposed atop the settling chamber are side walls 25 vand 26 and front and rear walls 2l and 23.

The walls 25, 26, 21 Vand 23 dene a rectangular case which is divided medially by a `depending plate 29 forming a baiile that divides the enclosed area into an inlet chamber 3o anda pulsation --chamber 3|. l:

vIn the pulsatio-n chamber I form a supporting grid 32 which comprises a plurality of structural members arranged in crossedrelation in the pulsation chamber and secured to the walls l 2B and 33. Thegrid- 32 supports the jig screen 34. Asshown in Figures 4 and 5, the jig screen 3i! lies upon the upper surfaces of the grid and divides the pulsation 4chamber into two zones, the

` lower adlt zone i On the upper face o! `the screen Isprovide shot `dividers 311 which segregate the sie vneeifintc Lrectangular areas `of substantially .smallei-fsize "tlnthetota1-areaotthe Jlgbed.

depth `or `from one to:

i mls have been-room v l :moet` ."rhereioreido not ed; asjst "41; to l i M i curved 'and haveupperxixid lower; segmental seats n 43 respectively. Between 'the segmental `central passages l5.`

` opposedpslrs of balls'inl Seris Of rimes 50.`

y material flow across '5| is mounted in the vibration tbgtheicumels j wall of the housing 63.`

Vtained in.`thec1osed i spring 69 betweenthe stirrup` 66 andthe face 35 Athe Aupper jig izone los.

The materials used to `form :heftig `prefscreen u, between the shot bed dividers; to `a three'linches:- Thelyig bdd needunot bei fotihd `suitable for the purmy .reference-tcy the use ci shottoiom :ne iis bod `a'.11l"ltlls-to4 be understood-that steel shot is described for the pitt-pose or illustrationonly.

l v the upper portion-or the walls :12s and `t3 I provide vibrator mounts yIl whichmay befweldthe walls. These mounts `tire seats I mount the vibrator balls 44 which have Rime shafts 49 and Mfhave their ends disposed in the central passages" of eochend oi' the dis bed `zone. .5 By means `of the depending-amis 4I fitted on the rlllle shafts and im,r rime walls 49 which iiesubstantially parallel tothe walls and `Blf These wallsextend downl l vaardiy to a point justabove theupperlsnriace of Between walls leinspaced apart relation :isa In Figure fi 'it maybe seen tht the rifllos 5l are disposed at a slightangle edges areslightly curved or-cuppedwas at tl.

Generally the preferable practice'ls tolemploy "cuppededges directed reari the Vrimes with their wardly or with concave l faces presented lto che thearrowlnlllguredl y i l l. i, Members 49` arepiovldedfwlthjoumal supports li!` which rise upwardly yand mountfthe'journals 1 $8 on the rectangular rullo-box,l Anasitator shaft journals 53 andispiovlded which rotative forc `"is opwith the pillley 55 by i plied to the shaft` "Ihepulley Blimay be keyed to` shaft u ootherwise' secured; By.r`neans foi-bolts side offthe shafts! has secured thereto l e `pluralityci'straps a1 which in tcm combineer] l o: shot :as other mateil., I mount the dependme Jfg `bed as indicated byV "oubli shotvorballstot `.steeldisiplaceclon the `colis news1-ine Usually thekdlaphragms `are formed of` heavy series `ofcbolts 19.-

* havccntral pivot holes 8| ietciiciatne disk. 1a against the Resilient diaphragms 15 16- are securedvby openings 6I and" B2 respectively.

molded rubber to` long vlifefuniier adverse ,ccnditicme centrato cf eeen diaphragm.: se-

c'urefthediaphragm/plate 18 by means of the `Each. of the plates is provided with `a. pair of spacedapart Betweenltheopenings 6l and'lZ` and'onthe cover 80.1 moimtivbearing standardsli which from the .perpendicular and that; theirlcwer Y passed through .thegplvot hole `bellchatillon. The bell crank lxaive'fli'xounted therein a pivot fpin 8.6 that is 81 on the double n has "on either` side ofthe pivot hole, alpair of oscillatorarms 89 and l81'.' having end plvotholes 90. Pins 9i are passed through the holes Il ofthe pivot ears `onthe diaphragm plates and through the holes'Q at the outerfends Tof the leverl arms 89 and 89'.`

I"Thelzvel'l crank membei` has also a pair of upf standinglarms `92,` 92fwhich form theiork Sainte which is fitted the `slide block 9d of Figure 13.

slide bloei; s4 is shown es parted for convenience of assembly. 'l l `In. journals 9E, 96' I mount the drive shaft 91 for `rotation and centrallyoi the drivefshaft is the actuator crank 98` supported by means of A The crank 98 isengagcd by the halveso theslideablelioui'nal slide block 94 rotation will impart a tipping motion piston-like actlonito the flexible diaphragms.

A `drive pulley loi .is keyedV te the drive shaft `91 `in line with the agitator shaft pulley 55; An`

endless belt `H12 encii'cles th pulley 55 a`nd`-IOL A Preferably I use a V-belt of rubber composition slightly loose.

`in the manner indicated in Material is fed to the jig iaundei-A ltand tailing material is carried away by means of' theoverow lounder |05. These launders 'are placed on eitherend of the jig bed thedrawings. In operation in a typical installation my' jig would be placed between `the discharge side oi" a,

i` ball mill `or othercrushing machine'and the feed.`

' means of my'machlne to classified Jfeed fmeterial l from the crusher mechimode of operation. Such A dependinginlet housing 63 is securedblowf'the opening 62 and forms theintake'chamberjd., A feed` duct 65 passes `through the wall 21 intofthe position by meansof the ot the valve plate. t t i In the lower wall of the `housing 63 V'Iialso provide the discharge `opening lllrwhichls spanned by the curved leaf spring 1|- that supports `the bolt 12 substantiallyfcentrally of` theopenlng 10.

On the outer face ofthe housing I providethe valvedlsk 13 securedto` the bolt by means of anut 14. `The normal tendency of the V'spring 1 I" u pans thepilnnervterxninalyof the duct, valvedlsk 61 on` lthepin fismainl to move throughgthe anced rctai'yshaft 5E. j ing the riilles ossillatei'ntherubber mount Adit in side of `a classifier mechanism. It is `possible by run directly the unanismto the jig` foriltreatment according to its afeed of material will contain `metallic as well as non-metallic material of a great vvariety of sizes and shapes and all having differing,specific'gravities` y The material pa'sses'nto the jig bed zone `:from the feed launderand flows toward the overflow launder. 'I'hewfirstmechanical `to this feed material is `that lencountered in the agitating` or `vibrating `iiflles v5l! which are caused operation of `the overbal- `The `side plates 49 carryajigging manner an A `the motion of the 1jilles.be ing backward'andioryvard.` The incoming feed is thus stirred or `spread oveii: the bed 4of the `jig anastratifieationef this feed material is thereby `considerably enhanced., `The settling of the `gold particles having a great speclflcgravity ontopthe bed `is aided andlasslsted'and the eiciency of the jig is `inip'rovc-:d over 4"those "devices in which flxedr'iflles areemployed.4 f

lA .constantlsupplylof water `provided lon the cuter face of the housing lltoclose the opening 1o.' 1

"pivot ears! 8-0 that bcdfby ineans of feed action imparted.

,inlet duct 65 and as indicated in` equally dis/tended but, in

this water, through the 'operation of the pistonjmeans A intake 'chamber 64 during 'aportioi'i of the k,cycle of operation of the bellcrank mechanism 83.4 At

a later/period'f'in the cycle of thejig-"it is forcefully discharged into".tlle''lli`i tcl1y of .the-.jig and imparts pressure. to r:the under side of' theshot bedof the jig.` This pressure risfproducedbypiston 'means/151 and applied to' the shot bedto cause it to become permeableby raising andthe individual elements to separate thernand to thus 1.6 is drawn intofth'e 'cui .of nuiais introaueedfinte the nuten, and the shot bed is onlyraised o-nce. l A

vAccording tothe principles of my linvention I produce a current in the hutch, not under pressure of gravity or under the lower pressuresobtainablefrom ordinary water supplyfsourcesibut withua positive high pressure imparted; through provideopenings for therv downward Ypassage of the material being concentrated. Gold Vlhas'a greaterspecific 'gravity than the steel balls normally used inthe shot bed and the rate of fall ofthe ,gold being `concentrated will thereforeibe greater thanthat of the shotbed. The gold will permeate downwardly through the interstices of thelshot ,bed material and fallinto lthe hutch Figure. 2 where these Vparticles are accumulated in the lower end of the settling chamber 2| indicated at |91. These concentratesvmay be drawn off through the clean-Out valve 23,

The action of the lever mechanismy 88 andA of the diaphragms thereby actuated is delineated in the Figures 8, 9, and l1. In Figure 8 the diaphragms over each opening are substantially of equal size and they are also substantially the showing, the action 'of the crank 98 is tending to raise' the right oscillatable. lever arm 89 and to d istend further the inlet diaphragm 16. rThis action maintains the valve member 13 tightly closed While at the same time the valve member r6l is drawn open against the urgence fof the spring B6 tof permit the inward flow of fluid through the ductv '65, which operation will culminate with the iilling ofy the chamber 54. Simultaneously, the piston means "i5 isbeing forcefully depressed into; the fluid of the hutch and to applyforce therein to create v a current that will flow to the underside of the permeable jig r,bed andv open it. Of course, in Figure S the piston means 'I5 has only travelled through' an initial portion of its stroke and as can beseenin FigureB it will be further depressed into the vjig hutch.

The chamber 64 is shown completely filled in Figure Q'and when the diaphragm isdistended as shownthe'valve 61 closes whenH the urgence of its spring overcomes the current of the inflowing fluid. Throughout the rdownward feeding stroke of the piston means 15, the valve 61' will remain closed but the valve 'I3 will open to permit the flow of fluid into the hutch during retracting or upward stroke 01y the piston means 15, the initial stages of which stroke are yillustrated in Figurel l0; The vacuum that'would normally create a suck-back on vthe under side of thediaphragm when it raises is compensated for by the incoming flow of the fluid that was in chamber Sil. During the retracting stroke s of the piston means 15 no other force is applied of the levers of the walking beam only one charge' the operation of the piston means. I permitthe jig bed to come to rest under the force of gravity by supplying a volume -offluid tothe hutch equal to the increase in volume ofthe hutch produced byA retracting the current .creating diaphragm.

Thus, during this period thejig'bedis quiet.'

In the showing of Figure A18 wherein I have illustrated the'modied structure in whichV the principles; of myjinvention have been incorporated, the hutch 2|) forms the usual inlet chamber 3|). The pulsation-chamber'wall 33 is to be seen and has attached'thereto as described, the launders |04 and |05. 'Ihe cover plate Hihas out therein the openings V| I; and I2 which are closed by the flexible diaphragmsll and H4 lrespectively. Ihe two diaphragms are operated bythe conventional walking beam 88 which is pivoted on pin 8S andwhich is oscillated or tilted by the crank 9.8.-' Theqdiaphragms' H3 and Hfi are of different size with the smaller being disposed over "occupy the void the opening I |72 to draw fluid into the inlet chamber` H5 through the, duct Hi.;V Because of the differential between the effect of theptwo diaphragmsin their up anddown" travel, a small quantity of fluid will be drawny into the chamber I5 and then when it is drawn intothe hutch by the force exertedby the .diaphragm H3, it will created by the'upward movement of that memberand will thus relieve the suction to a degree that might otherwise be applied to the underside `of theshot bed. This produces a slightly longer interval during whichv the shot bed is falling freely so that a greater amount o f metal particles may pass therethrough.

. `I .I 4. This increases vsupports |29.

.-differentflengths.

1 In Figure 19 the same effectas isproduced in of the the Figure 18 device is obtained by the use walkingbeam |20 which-has arms |2| and v|22 of Y The effect is tonincrease the leverage applied, on.v the diaphragml H3 andto decrease Ythe leverageA operable upon diaphragm the stroke ofthe diaphragm I I3 whileA at the Sametime suction stroke of diaphragm H4 draws less fluid into chamber H5.

InfFigures 20 andl21 I teachv the use of a variable fpivot for ther walking beam I=Z54which is provided with the slot tional pivot hole..

|26 insteadpfto the conven- I A pivot pin |21 has eccentric trunnions |28 which arelmounted in the bearing A leverIEIy is keyed or secured to a trunnion to assistfinturning that member and this lever isv held in adjusted position by means of diaphragms.

thepin |3| which cooperates with the holes in the edge ofthe quadrant |32. By swinging the lever, |39 Vthe crank pin |21 is caused to swing about the axis of the trunnions and to thus shift the pivot point with relation to the centers of the l In this way isit possible toshift the actionlof the walking beam and to increase j or decrease vthe stroke of thepiston'diaphragms.

rjoinder. to hold the plate IQI in adjusted position.

The walking beam |35 shown in `Figure 22 has the usual central pivotal mounting lonpin I3@ but the arms ofthe member are slotted at |31 and |38` and the pins |39 and Idil are tted thereto.' The cover plate MI is movablel laterally across theupper mouth of the hutch |42 and gasket Y |43 prevents leakage at the point of Slotted arms :IM: are engaged bybolts By sliding l ore being milled.

` tioned `over the jig the plate laterally the relative distances between the pivot pin |36 and the point of attachment of the'diaphragms I I3 to the arms of the walking beam |35 may be varied to increase and decrease the respective leverages.

By the use of this arrangement various sizes of diaphragms may be employed in the adapting of the jig to the conditions under which it may be required to operate. This device is particularly useful in running .pilot or test milling operations upon a type of ore. When an ore mill designer is called upon to specify the type of equipment that should be built into an ore mill he must fit the equipmentto the demands of the Various slight alterations will often produce resultswhere failure had existed before. The mechanism of Figure 22 is primarily useful for such testing andexperimentlng.

I claim: 1. In a mineral jig wherein a pulsating current is employed in` a jig hutch to periodically increase and decrease the permeability of a jig bed under a flow of feed material, reciprocal means for imparting an intermittent current to the fluid in said jig hutch, means for intermittently introducing fluid to said jig with force, said introduction of fluid being timed to occur during the retracting stroke of said reciprocal current imparting means, a rotatable shaft having means thereon for reciprocating said reciprocal means, a plurality of vibrator mounts on said hutch adjacent said jig bed, each vibrator mount supporting an upper and a lower segmental seat, a resilient vibrator ball positioned in the seats of each vibrator mount,` an open bottom riflle box posibed and having a plurality of trunnions, each trunnion associated with a vibrator ball, an unbalanced shaft associated with said rime-box to agitate the same, means associating said unbalanced shaft with said rotatable shaft for rotation therewith, and means for rotating said rotatable shaft.

2. In a mineral jig wherein a pulsating current is employed in a jig` hutch to periodically increase and decrease the permeability of a jig bed under a flow of `feed material, reciprocal means for imparting an intermittent current to the fluid in said jig hutch, means for intermittently introducing fluid to said jig, said introduction of fluid being timed to occur during the retracting stroke of said reciprocal current imparting means, a rotatable shaft having means thereon for reciprocating said reciprocal means, a plurality of vibrator mounts above said jig bed each including a resilient member, an open-bottom rile box having a trunnion associated with each resilient member to support the rillle-box above said jig bed, an unbalanced shaft journalled on said rifile-box to agitate the same, means associating said unbalanced shaft with said rotatable shaft for rotation therewith, and means for rotating said rotatable shaft.

3. In a mineral jig wherein a pulsating current is crease and decrease the permeability of a jig bed under a flow of feed material, reciprocal means for imparting an intermittent current to the fluid in said jig hutch, means for intermittently introducing fluid to said jig, said introduction of fluid being timed to occur during the retracting stroke of said reciprocal current imparting means, a rotatable shaft having` means thereon for reciprocating said reciprocal means, a flexible open-bottom riflle box supported in spaced relation above said jig'bed, an unbalanced shaft associated with said riille-box to agitate the same, means associating said unbalanced shaft for rotation therewith with said rotatable shaft, and means for rotating said rotatable shaft.

4. In a mineral jig wherein a pulsating current is employed in a jig hutch to periodically increase and decrease the permeability of a jig bed under a flow of `feed material, reciprocal means for imparting an intermittent current to the fluid in said jig hutch, means for intermittently introducing fluid to said jig, said introduction of fluid being timed to occur during the retracting stroke of said reciprocal current imparting means, a rotatable shaft having means thereon for reciprocating said reciprocal means, an open-bottom riille box flexibly supported in spaced relation above said jig bed, an unbalanced shaft associated with said rime-box to agitate the same, means associating said unbalanced shaft for rotation therewith with said rotatable shaft, and means for rotating said rotatable shaft.

LESLIE E. TU'I'HILL.

employed in a jig hutch to periodically in-`

Images