US2456074A - Overload responsive system for controlling feed and operation of crushing apparatus - Google Patents

Description

Dec. 14, 1948.

Filed May 29, 1944 R. C. NEWHOUSE OVERLOAD RESPONSIVE SYSTEM FOR CONTROLLING FEED AND OPERATION OF CRUSHING APPARATUS FEED HOPPER 2 sheets-sheet 1 Dec. 14, 1948. R. c. NE'WHOUSE I OVERLOAD RESPONSIVE SYSTEM FOR CONTR OLLING FEED AND OPERATION OF CRUSHING APPARATUS 2 Sheets-Sheet 2 Filed May 29, 1944 Patented Dec. 14, 1948 2356,0721." OVERIJOAU RESPONSIVETSZYSTEMTORiGON TROILLING FEE-D AND? OPERATION: OF GRUSHI-NGL APPARATUS.

Ray 0. Newhouse, Wauwatosaa Wis, ,a'ssignor' to; Allis-Chalmers Manufacturing; Company,"v Mib. waukee', Wis, a, corporationiofg Delaware,

Application-M312951944; Serial Na 53mm:

(ci ar-ea). f

'Z'ICIaiinS.

Thisinventioni relates to apparatuszfor crush. ing material such as stones ores etc; betweenrelatively moving, crushing membersfln which: it is desirable toprovide: for; automatic safety, con. trolto prevent damageitoi the crusher as a..r.esult of excessive crushing; pressure; due to unorushable material, packing conditions; on any;- other. abnormal condition;

An: object of the" invention isto provide for: automatic. cutting; off: of feed to the crusher. in, case, of minor abnormal conditionssathatttheo crusher: may clear" itself and. return-to. its proper,

setting.

Another objectis =toiprovidejor, automaticstopa ping offlthe crusher operation uponioccurrenceof. serious abnormal:- conditions Still another object of" the present.- invention. concerns provision, in a crushenof, safetyv control meansspermittingwyielding. of i a crushingmember, under onlyexcessive: crushing. pressures-J and automatically returning the.crushing..member to. normal crushing position only, after substantially,- complete a clearance .ofthe. crushing. chamber.

The invention having. the above and". otherjobjects w-hich may appear, herein..may, be carried into. effectaasrfully. described"hereinlielowun connection' with. the accompanying; drawings; which: o

lfis. a. partlyschematfc. View" showingfai crushenequipped. accordingt'o the invention; and

Fig. 2 is an. enlarged view of a portion of the apparatus. shown male. .1 includinggthev accumue lator and;contr.ollswitch actuating means: shown in vertical cross. section.

In. the. embodiment of the. invention shown: in the drawing, the crusher I. may be: a; gyratory, crusher. of. a.t'ype well known in the: artfiyhavingg a. gyratory headv supported by a hydraulic" jack. It will be. unnecessary to describe in detail the. internal structure andworkings ofsu'ch' a crushersince suitable crusher structure has been fully described.v and illustrated in. US. $5 Patents Nos: 2,021,895 issued. to R. C..Newhousej et and? 2,022,135 issued. to RZCI Nwh'ousaand in the; copending application Serial. No.. 530,924, filed April. 13, 19.44,]by Alexander; J; R'oub'alf. Itiwillf be lunderstoodithat. the hydraulic. syst'emexternal'; to the: thrust. bearing supporting. cylinder anti" piston shown in the above .mentioned'patents. and; application ismodified. according. to the, present. invention. as fully. described. and illustratedl herein.

According, to the present invention, the. gym.- torycrusher I. isequipped withaieedf controlling, mechanism. on feeder; 2 drivenby, feeder motor;

2 3.1-. 'I hezfeeder; 2 mayyfeedzrock, or othersmaterial to.:-b.e crushed, into the crusher: l': whereit passes; between relatively movable crushing; members-l, actuated. by; suitable: crusher;- member? actuating;

meansa as shown inthe above: mentioned; prior:

natentsi-and oopending application: Tihe zcrushen l:- is driven by a crusher-motor, lshowniin Eie; I 1,

Crusher. l is; equipped:withiez hxdraulic head: support: jack 6;; to which: fiuidi may; be: suuplied:

. andtfrom which fluid may beawithdrawnthnougha hydraulic fluidoon'cluit. l connectedlitor theshighp pressureside of. apressurerrelieffl valve.:8 oillsulta able-structurewvell knownlinathe-artt. The-relief; valve; 8; is, arranged to prevent the.- passage, fluid. from jack 6. except. when thepressure. ext cee'ds a. predeterminedwalue; for which, thearelieii valve; is set;, Since.thefluidflpressunesin;.thetjacl 6.: and. conduit. 1, during crusheroperation willihef pronor-tionalv to the. crushin pressure, the,:relief2 valve; 8-, will bessettoopen when thefiuidlpres; sure exceeds that which would supporttthemaxi; mum safe. crushing pressure Between! K; 6 andreiief-Tvalveii, a conduit.,9.leads.to thadls, charge side of acheckvalvelfl; arrangedftapree vent the. escape. oi fluid fromv jack. 6. thziougli conduit. 9.; From. some. point. int the hydrauliit system: betweenthe jack; 6' and. the. teller? check; valvest. and lll,.respectively,. a consist; I]? may, bev connected to a handlpumn 12,,whiclii may; be arranged tor-supply fluid to. the. j acli; E'fi'omrtli'e reservoir? !3. Hand. puma I2. is used. to. forcefluid unden pressure into. thesystem to raise the. crusher members-or head to. its, proper. seam-greereasonsv to be described'hereinaftert,

From the discharge or low. nressure side. ofth'e" relief valve. 8 and the supply or inlet connection of. the check valve ill; a common conduit "is connectedit'o the fluid" pressure spa'ce'of anaotcumulat'or. lEilwhich is arranged. totreicieive'fiuidi from. the conduit M at a minimum pressure suf ficient'. to. support" the crushing'members': of the? crusher. I in theirmormalcrushing 'positionmudeii no load c'onditions, that is: when the crusheris; runningjwithout any materialybetweenithecrush? ing mernber-s. Preferably, the pressurefofwliieli the accumulator. will;be,set"wilrbetslightlylligfier than the minimum.

A bleedingcockl tT'may, be. provided mpressure conduit. 1. forbleedin'gfiuidf fi'omfithe'" hydraulic, jack, B'when it is desiiedfbr anyrea sont'oopen the" crushing 'members': A stop valve? I,8fmay. be placed in. the conduit?! lbetween: handpjump. I2"andithe cylinder B tor isolate'the handkpump duringnorma'roperation'ofti'ie crusli=- er. Aiibleeding. cock'. l9" maybenrovided between? The accumulator l6 shown in Fig. 2 consists of an accumulator cylinder 2| having a piston or plunger 22 normally biased downwardly against the end of the cylinder 2| by an accumulator spring 23. The plunger or piston 22 is slidable upwardly in the cylinder 2| by the pressure 1 of fluid admitted through conduit l4. Spring-23 is precompressed to a degree somewhat greater than that which would be just sufiicient to prevent displacement of the piston 22, by hydraulic pressure less than that sufficient to support the crusher head under no load conditions.

i The upperend of the piston 22 is beveled to provide a cam surface 24. In the cylinder wall of" theaccumulator cylinder 2| are a pair of switch actuating plungers 2B and 21 having conical ends projecting into the path of the cam surface 24 ataxially spaced points. The plungers 26 and 21 are biased inwardly by springs 28. A normally closed feed control switch 29 is mounted on. the accumulator cylinder 2| in such a position that it will be actuated to a circuit opening position by the switch actuating plunger 26 when the accumulator piston 22 is displaced by a predetermined amount from its normal position as shown in Fig. 2. A second normally closed switch for'crus h'er control is mounted on the accumulator cylinder 2| in such a position as to be actuated to 'acircuit opening position by the switch actuating plunger 2'I'when the accumulator piston 22 h'as "been displaced by some predetermined amount larger than the amount necessary to actuate plunger 26.

Thecrusher driving motor 4 is energized from a' power line shown at 32 which also supplies power to operate the feeder motor 3. The feeder motorl3jmay be started and stopped by a contactor" 33 which'may be closed and held in closed position by a holding coil 34 energized through switch 29. The crusher motor 4 may be started and stopped by a contactor 36 which is actuated to closed position and held closed by holding coil 31.,energized through switch 3| and normally closed stop switch 38. A starting switch 39 may be provided to actuate the contactor 36 if desirable whencrusher control switch 3| is opened. Ari alarm circuit 4| may be arranged to give analarin when the speed control switch 29 is opened. The alarm circuit 4| is normally open during crusher operation, being held open by holding coil 42 in a manner well known in the art. The alarm will sound when the feeder motor and coil 42 are deenergized by the opening of control switch 29. A similar alarm circuit may beprovided 'in an obvious manner to sound 'a different alarm device, such as a horn, upon deenergization of the crusher motor by opening of control switch 3|. A showing of such an alarm circuit has been omitted in order to avoid unnecessary complication of the drawing.

In operation, the crusher members are first set to -their proper normal crushing positions by opening stop valve 8 and pumping hydraulic fluid into the jack 6 until the proper crushing setting has been reached. When the crusher isproiaerly set, the stop valve l8 may be closed. Conduit l4 and the space below piston 22 in the 4 accumulator cylinder 2| are filled with hydraulic fluid before the crusher is placed in operation.

With the accumulator piston 22 resting against the bottom of the accumulator cylinder 2|, the crusher and feeder switches 29 and 3| Will be closed and. energization of the power line 32 will cause thecrusher motor. a and feeder motor 3 to operate, giving a normal crushing motion to the crushing members of crusher and feeding material into the crusher feed opening. So long as the crusher is operating normally, the fluid pressure in jack 6, being proportional to the crushing pressure between the crushing members of crusher will be insuflicient to open the relief valve 8. Crusher i will continue to normall crush material until an excessive crushing pressure, such as might be caused by a piece of uncrushable material between the crushing members, or by packing of fine material between the crushing members, causes the hydraulic fluidpressure in jack 6 to exceed' the setting of relief valve 8.

When relief valve 8 is opened by excessive whereupon the contactor 33 will fall open, and

the feeder'motor 3 will stop, cutting ofi feed of material to the crusher If the uncrushable substance in the crushed, or the packing condition, or other cause of excessive pressure is of a minor nature, the crusher will clear itself of the abnormal conditions by operating without feed of material.

I As soon as the crusher has-been cleared of the substance causing excessive pressure, the crushing pressure will fall to Zero, and the hydraulic fluid pressure in the jack 6 will fall to its no load magnitude. The minimum pressure in accumulator it being at least great enough to return the crushing members to their normal crushing position under no load conditions, as

soon as the pressure in cylinder 6 has fallen to no load magnitude the piston 22 will force fluid through. the, check valve iii and conduit 7 into jack 6, returning the crushing members of the crusherl to their normal operative position. The accumulator piston 22 will fall to the bottom of the cylinder 2| allowing switch actuating plunger 26 to be forced inwardly by spring 28 and allowing thespeed control switch 29 to close, energiZing holding coil 34 which will closethe contactorand start the feeder motor 3. The crusher will now resume normal crushing operation.

,In case a very large piece of uncrushable material gets between the crushing members of crusher or a packed conditionv occurs that will not be cleared even by substantially the maximum possible opening of crusher members for which the crusher structure provides, the crushing pressure will continue to be excessive and to force the crushing members in open direction forcing fluid through conduit I and i4 and raising accumulator piston 22 until the cam surface 24 pushes out the switch actuating plunger 21, opening the pressure control switch 3|, deenergizingv voltage coil 3'1! and opening contactor 36, thus deenergizing the crusher drive motor 4 and stopping the crusher. This arrangement willstop the crusher before the crushing mem bers have been forced to their maximum structurally possible opening. This will prevent the occurrence of a jam in the crusher which 1 could he clear'ed'only by'burning out or shoveling out the oflending substance. Since the crusher membersarestopped at some point short of their maximum-open position, the operator oan open the: bleeding cock ll, or operate pump to withdraw fluid from jack 6 and permit the crushing members to open, thus loosening the offensive material in the crusher and allowin it tofall' through or be dislodged without diflicultyi I 1 Whenthe abnormal condition has been cleared, and there is nomaterial between the crushingmembers, thefluid pressure in jack 6 will fall to it'snoload' value or below and the accumulator piston 22 will'force the fluid from the accumulator into the cylinder (5 until the'crushing memhere have been raised toward their normal position'; Iffluid has been withdrawn through'the' bleeding-cock H, or'through pump l2, the'crushing'members will'not return to their proper crushing position; The operator will then open the sto'pvalve l8- and operate the hand pump l2 until suflici'ent fluid has been pumped into the jack 6 to'raisethe crushin membersto their normal crushing'position. The crusheris then in condition tobe restarted and operated normally.

If'ouring normal operation the feeder 2 stops frequently; or'thealarm M informs the operator that the feeder is frequently stopping, it is probablethat too much material isbeing fed to the crusher; resulting in repeated occurrence of excessive crushing pressure suiii'cient to open the crushing members slightly. When this condition occurs,.the operator can slow down the feeder motor 3 or otherwise reduce the rate of feed to the crusher.

ItTWill'be'understood that the specific structure shown in'the drawing is illustrative only and that the invention can be applied to crushers of any type in which the crushing members are displacea'ble from their normal operating positions an excessive crushing pressure, by the use of mechanical expedients which will be apparent to persons skilled in the art. The invention is, accordingly, not intended to be limited to'the structure specifically shown in the drawing and particularly described herein, but is intended to include such modifications and equivalents as may readily. occur to persons skilled in thelart' within thescopeoi the appended claims.

It: i's claim'ed and desired to secure by Letters Patent:

11 Material crushingapparatus comprisingrelatively movable crushing members, actuating meansito relatively move said crushing members tn crush. material therebetween, support means for said members, comprising a hydraulic jack inwlii'ch a trapped body of hydraulic fluid resists relative displacement of said members in an opening direction by normal crushing pressures, a fluid pressure relief valve connected with said jacli and" adapted to release fluid from said trapped body under a predetermined excessive pressure, said support means yielding solely through" escape" of fluid from said; trapped body through said relief valve, hydraulicfluid'pressure accumulator means adapted to receive all fluid discharged from said relief valve under excessive fluid pressure and to maintain thereon a.mini-'- mum fluidlpressure sufficient to actuate said jack toreturn said crushing members to normal operative positions only under substantially no load conditions, a fluid conduit connecting said accumulator to said jack, and means in said conduit to prevent? now? through said conduit from said jack under normal operating conditions,v

2; Material crushing apparatus comprising relatively movableifcrushingr members; actuating means to relatively move said crushingmembers to crush" material therebetween, support means for saidfmembers; comprising a hydraulic jack in :whic'h' a trapped body' of hydraulic fluid resists relative displacement of? said members in an opening direction by normal crushing pressures, a' fl'uid' pressure relief valve connected with said jaoleand" adapted to release fluid from said trapped? body" under" a predetermined excessive pressure, said supportmeans yielding solely througnescape'of fluid from said trappedb'odythrough said relief valv'e, hydraulic fluid pressure accumulator mea'ns adapted to receive all: fluid discharged from said: relief' Valve under". excessive fluid pressure"an'd to maintainthereon a minimum fluid pressure sufficient to actuatesaid ja'ck t'o return' said crushingmembers't'o normal oper ative positions only under" substantially" no load conditions;- a fluid conduit connecting said ac cumulat'o-r to said jack; and means in said conduit to prevent flow through said conduit. from said'ja'ck' under normal operating conditions, means controlling the feeding of material to said crushing members, and means responsive to. a; predetermined yielding movement of said mem-- bers in opening direction: and operatively" connected to said feed controlling means to cutloft the feedingofmaterialupon o-ccurrence= of such yielding movement; I

3. Material crushing. apparatus comprisingrel ativelymovable crushing? members; actuating; means toi relatively move said crushing members: to. crush material; therebetweem. support means. for said members, comprising; a hydraulic jack? in which a trapped body of hydraulicfluid resistsi relative displacement of said members in an". opening direction by normal crushing pressures, a fluid pressure relief valve connectedwitn said: jack and adapted to release fluid from: said trapped body: under a predetermined excessivepressure,: said support means yieldingv solely through escape of. fluid from said trapped body" through saidrelief valve, .hydraulic fluid pressure. accumulator means adaptedto-receive all fluiddischa-rged from said relief valve underexcessive. fluid pressure andztomaintain thereon-a minimumfluid pressure sufficient to. actuatesaidjach to return said crushing membersto normal oper-- ative positions only under substantially no load conditions, a fluid conduit connecting said accumulator to saidrjackrandmeansin said conduitv to prevent flow through said conduit-from said jackunder normal; operating conditions, means controlling the feeding ofrmaterial tosaid crushingmembers, and means responsive tov a pre-- determined. yielding: movement of said members inopening.- directionand operatively' connected tosaid feed c0ntrollingmeans to=cut off thefeeding of material upon occurrence osuch yielding: movement. and secondmeans. responsive to:- a predetermined yielding movement of: said members-in an openingg.direction-and operatively connected to said crusher actuating means to-stop:

crushing: action: of said crushing members upon: the occurrence of such yielding: movement, said first; and:.- second movement responsive means? being so correlated: that" at substantially greater:

ing movement as determined by the structure of the apparatus.

4. The combination of a crusher having a power driven feeder, relatively movable crushing members, means to actuate said crushing members, hydraulic jack means normally resisting displacement of said crushing members in relation to each other, a check valve normally closing said jack to escape of fluid therefrom and permitting fluid to be forced into said jack, a fluid pressure relief valve normally closing said jack against escape of fluid therefrom and permitting fluid to escape therefrom under abnormal pressure caused by excessive crushing pressure between said members, said jack means being adapted to allow said crushing members to yield in opening relation to relieve said excessive crushing pressure solely through escape of fluid through said pressure relief valve, a fluid pressure accumulator connected in closed relation with the discharge of said fluid pressure relief valve and the inlet of said check valve, and adapted to receive fluid discharged from said relief valve and return, said fluid through said check valve under a predetermined pressure suificiently great to support said crushing members only under substantially no load conditions, and means responsive to the action of said accumulator in receiving fluid and operative to stop said feeder, and to restart said feeder upon return of said accumulator to its normal condition.

5. A crusher system comprising a continuously acting power driven crusher having relatively moving crushing members, a feed control means to supply material to be crushed to said crushing members, yieldable means normally supporting said crushin members in predetermined operative relation and responsive to a predetermined excessive crushing pressure between said members to permit said members to yield relatively in opening direction, resilient energy accumulator means connected with said supporting means in a manner to accumulate energy as a result of yielding movement of said crushing members in amount sufiicient to return said crushing members to normal operative relation from relatively displaced positions under no load conditions, said resilient energy accumulator means being constructed and arranged to accumulate such energy at an energy level only just high enough to return said members under substantially no load conditions, energy transfer check means connecting said supporting means and said accumulator means and constructed and arranged to normally prevent the transfer of energy from said supporting means to said accumulator means and to permit a flow of energy in the reverse direction under no load conditions, and means responsive to relative displacement of said members from their normal operative relation and operatively connected to said feed control means to cut off supply of material to said crushing members during such displacement.

6. A crusher system comprising a continuously acting power driven crusher having relatively movin crushin members, a feed control means to supply material to be crushed to said crushing members, yieldable means normally supporting said crushing members in predetermined operative relation and responsive to a predetermined excessive crushing pressure between said members to permit said members to yield relatively in opening direction, resilient energy accumulator means connected with said supporting means in a manner to accumulate energy as a result of yielding movement of said crushing members in amount sufficlent to return said crushing members to normal operative relation from relatively displaced positions under no load conditions, said resilient energy accumulator means being constructed and arranged to accumulate such energy at an energy level only just high enough to return said members under substantially no load conditions, energy transfer check means connecting said supporting means and said accumulator means and constructed and arranged to normally prevent the transfer of energy from said supporting means to said accumulator means and to permit a flow of energy in the reverse direction under no load conditions, means responsive to relative displacement of said members from their normal operative relation and operatively connected to said feed control means to cut of! supply of material to said crushin members during such displacement, and a second means responsive to relative displacement of said members from their normal operative relation and operatively connected to the crusher drive to stop crushing action of said members, said first and second displacement responsive means being so correlated that a substantially greater predetermined displacement will be required to stop said crushing action than to cut off said supply of material, said predetermined greater displacement being less than the maximum possible displacement determined by the structure of said supporting means.

7. A crusher system comprising a continuously acting power driven crusher having relatively moving crushing members, means to supply material to said crusher to be crushed between said members, yieldable means normally supporting said crushing members in predetermined operative relation and responsive to a predetermined excessive crushing pressure between said members to permit said members to yield relatively in opening direction, and resilient energy accumulator means connected with said supporting means in a manner to accumulate energy as a result of yielding movement of said crushing members in amount sufficient to return said crushing members to normal operative relation from relatively displaced positions under no load conditions, said resilient energy accumulator means bein constructed and arranged to accumula'te such energy at an energy level only just high enough to return said members under substantially no load conditions, and energy transfer check means connecting said supporting means and said accumulator means and constructed and arranged to normally prevent the transfer of energy from said supporting means to said accumulator means and to permit a flow of energy in the reverse direction under no load conditions.

RAY C. NEWHOUSE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,762,379 Bates June 10, 1930 2,022,135 Newhouse Nov. 26, 1935 2,249,364 Osgood July 15, 1941

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