US1592125A - Die-casting apparatus - Google Patents

Description

Patented `July 13, 1926.

UNITED STATESI l 1,592,125 PATENT OFFICE.

CHARLES PACK, or ELMHURST, NRW YORK, AssIGNoR To noRaLER mE-CAsrING Co., A CORPORATION or NRW YORK.

DIE-CASTING APPARATus. v

Application mea october' 2v, 1923. serial No. 671,694.

My invention relates to the art of die casting of metals and more mechanism in a die castlng apparatus for containingthe molten metaland delivering 4it to the die under. pressure.

There are two general types of such mechani'sms, one in which the meta-lis delivered 'directly from the melting pot to the die, and the other in which asuitable charging pot or ladle operates automatically to obtain y a charge of the molten metal from the melt-v ing pot and to deliver` the same to the die. It is the more common practice to employ a pressure fluid, such as compressed air, to

develop the pressure upon the metal, either.

in the melting pot in the first type of mechanism, oiin the charging pot or ladle in the second type of mechanism, to force the metal through the gate opening into the die.

Ubviously, a mechanism in which theA metal is delivered directly from the melting pot to the die is in some respects preferable. It has the advantage of simplicity' in that no ladle filling mechanism is required operating either to submerge a movable ladlewithin the molten metal and then bring the ladle into registry with the gate opening to discharge its contents within the die, or, with the ladles in the form of a stationary charging pot disposed within the molten metal and having its mouth registering with the gate opening, operating to open and close a controlling valve to admit molten'metal to the charging pot. It does not have the surfaces, both lnterior and exterior, of the ladle to be attacked by the casting alloy, and for this reason less impurities are contained within the. casting metal.

However, the type of mechanism in which` the metal is delivered directly from the melting pot to the die,`in the forms heretofore proposed, has had certa-in well recognized disadvantages. It has been found impossible to obtain a valve construction controlling the admission of the molten metal to the die, which could withstand the deleterious action of the casting alloy for any substantial period of time. Furthermore, this type of mechanism has necessitated the exposing of a large surface of the molten metal to the pressure fluid and the resultant formation of undue quantities of oxides and other dross. On the other hand, the charging otl type of construction has the advantage t at the pressure iuid comes in momen ary-contact only with that quantity of the molten particularly to the man which is being forced-within the die of th direct type of apparatus heretofore prop sed have been suliicient to prevent their practical use to any considerable extent, and l for this. reason, the charging ot type of mechanism has almost universa y been employed despite its shortcomings, referred to above. The desirability of a satisfactory direct charging type of mechanism which would dispense with 'the charging pots or ladles, has long been recognized, but to my knowledge none has heretofore vbeen produced.

It is an object of my invention to provide fromhe charging pot. The disadvantages a `mechanism for containing the molten metal and delivering it directl under pressure as desired to the die, whic will be free from the disadvantages of that t pe of mechanism above enumerated, whiie preserving all of the advantages inherent in that type of mechanism. Another object is to provide a mechanism for automatically replenishing the metal in the melting pot as it used for casting so as to keep the level of the metal in the pot substantially constant. Still other objects and advantages of my invention will appear from the following description. A

In accordance with my invention I employ `a melting pot having a discharge spout connecting with the bottom of the pot, the dis charge nozzle of which is above the normal level of the metal in the melting p'ot, and registers with the gate'opening which may be, for example, in one of the die clamps and thence through the adjacent die part, or,

as in some types of mechanism, at the parting line of the die parts. In other words the melting pot approximates a U-shape,

being generally of the form of the gooseneck ladles employed in connection with -melting pots in the die casting industry.

The size of the meltingpot willbe determined by the rate at which 4the metal is used, its capacity being such that" the tem' perature of the molten metal will not be materially reduced by the melting of ingots fed tothe pot at proper intervals to maintain the level of the metal substantially4- constant'. In order to force a charge of the metal into the die' for each-casting operation, means are provided for delivering pressure fluid, such as compressed air, upon the 1.10 A' top of the metal. u .l

This form of meltriig pot dispenses with the need for valves to control the connection between the melting pot and the gate opening, It will be appreciated that it is desirable to maintain the level of the metal Within the pot as near as possible to the dischar e opening or nozzle of the pot. As the leve of the metal recedes within the spout a larger air chamber at the nozzle end is thereby provided with the result that more air is forced within the die as the metal is expelled through the nozzle, which tends to form blow-holes in the casting. Furthermore as the level of the metal falls the size of the air chamber in the top of the melting pot increases. Since this chamber is in effect an expansion chamber for the air, it is manifest that economy demands that its size be kept as nearly constant as possible. My invention, therefore, contemplates means for automatically maintaining this level approximately constant. In accordance with my invention Iprovide a mechanism which is automatically controlled by the casting operation itself for replenishing the metal within the pot at such intervals as is required to prevent the level of the metal from falling substantially below the nozzle opening. Preferably l provide automatic means for feeding ingots of the casting alloy to the-pot as required. Manifestly, as the rate of metal consumption varies, it will be necessary correspondingly to vary the frequency at which the ingots arel fed to the melting pot, and in accordance with my invention, the automatic feeding means which is controlled by the casting operation is susceptible of adjustment or change so as to regulate the relative frequency of the feeding operation.

My invention contemplates other features of constructionl and details and arrangement of parts, as will hereinafter more fully appear. I shall now describe the illustrated embodiment of my invention and shall thereafter point out my invention in claimsl Fig. 1 is a side elevation partially in section of an apparatus which embodies my invention;

Fig. 2 is a sectional detail on an enlarged scale, taken on line 2--2 of Figure 1;

Fig. 3 is an enlarged detail showing in section a fragment of the sprocket chain with one of the impulse lingers secured thereto.

The base 1 of the apparatus supports at its one end a furnace 2 resting upon which is the melting pot- 3. This melting pot is roughly of a U-sha e, the discharge leg of which is smaller t an the main body of the pot and partakes generally of the form of t e spout terminating in a laterally extending discharge nozzle 4. The top of the pot is closed by a plate 5 through which enters a pipe 6 for compressed air or other pressure fluid controlled b a. hand valve 7. Mounted on the bed ofy the base 1, are supports for the die clamps and the mechanism for opening and closing the die. Longitudinally of the bed of the base extend one or more guide rails 8, upon which slide the clamp member 9 for the gated half of the die and a bracket plate 10 connected to the clamp 9 by rods 11. Guided upon these rods l11 is the clamp member 12 for the other half of the die which is connected to the bracket member 10 by a'toggle consisting of the link 13 pivoted at its forward end to a lug on the rear face of the clamp member 12, and link member 14 which is pivoted at one end to the link 13 and at its other end to a lug on the front face ofthe bracket member 10, The rear pivot 15 for the link 14 is a short stub rock shaft on which the link 14 is secured and to the opposite end of which is secured a pinionpl.- -This pinion engages with a rack 17 secured on rthe bed of the base 1. The clamp member 9 for the gated half of the die has the ate opening through a boss 18 which is a apted to register with the nozzle 4 when the die support is in the casting position shown. It is evident that as the bracket member 10 is retracted, 1t will withdraw the die support away from the nozzle 4 and at the same time will o `en the die by retracting the clamp mem r 12 relative to the clamp member 9. This die opening operation is effected by the breaking of the toggle 13, 14 due to the rotation of the pinion 16 upon the rack 17. It is also apparent that the reverse movement of the bracket member 1() will again close and lock the die due to the reverse rotation of the pinion 16 on the rack 17 and the consequent locking of the toggle 13, 14. This die opening and closing mechanism is similar to that claimed in the co-pending application of Marc Stern, filed May 24, 1924, Serial No. 715,712, and forms no part of my invention.

Any suitable mechanism may be employed for operating the bracket member 10 to o n and close the die. In the construction illiiestrated I have shown a compressed air motor 19 which operates the connectingrod 20 attached to the rear face of the bracket member 10.

The automatic ingot feeding mechanism controlled by the casting operation so as to operate in properly timed relation thereto, will now be described.

Supported u n a standard 21 arising from the bed o the base 1 are two sprocket wheels 22 and 23 which are connected by a sprocket chain 24. On the cross pins of this sprocket chain are removably secured a plurality of impulse fingers 25. As shown, these impulse fingers extend out some distance beyond the face of the chain, and

their attaching parts are of just the right length. to span the hubsoi:l -two adjacent cross pins of the chains. The ends of the attaclnngparts of the impulsey fingers are accurate, one end going substantially half.

way round its hub and the vother end going less than half way round so astopermit of ,the ready` application of the. finger, .the

yshorter end .being lsecured to its hub by a set screw.

increased or decreased.

v other end against a collaron the-.push rod These fingers 25 are arranged toactuate a horizontalpush rod 26 which is supported at one end inzan arm 27 extending up from thestandard 21 and its other end in a standard 2,8 rising. from the base adjacent the lfurnace 2. This push rod is 'normally retracted by a spring 29 which bearsgat o ne end against the standard 28 ,and wlth its This pushrod 26 operates anescapement 1 mechanism to release an ingot with each actuation` of. the push rod. In the` form shown,.-the ingots 30 are contained in a vertical chute 31 which leads through the plate :5 into the Vr top-of the pot. The ingots are of cylindrical form with a reduced lower lend so as to provide a shoulder-for the engagement 'of the escapement mechanism. A. link 32 is pivoted at .its centre to a lug on thetop ofthe standard f28, and hasa slotted opening in its upper end which `en- Igages/over a pin on the push rod 26. Below its pivot the llink 32 carries', byA a slotted connection, a: finger 33, which 'extends it from following the' lowermost' ingotas i-t kfalls into thepot 3.

A suitable gate mechanism,

ure 2, is provided in the chuteunderneath the lowermost ingot. Thisy gate isauto- -matically opened when the lowermost ingot is Areleased and is -.again `closed as the A. spring 29. returns the push rod to its -outward position,. thereby serving to. close the compression chamber above the metal in the pot whenthe Avalve?l is openedand the pressure .fluid admitted. In the :form shown, 'the vchute 31. has` a ytransverse enlargementv 34 ,within whichA is., -a horizontal swinging"closurefdisc 355011` one endlof a pivoted Iloellzcra'nk 36. v'I heother end-of Itwill thus be understood thatthe number of these fingers can readily be .termined distance.

VShower; Fig,-y

thenbell crank is connected ltoda link 37 to the .outerend vofA which is pivoted a link 38 forming a continuation at its upper end .with the lower end ofthe link 32.' In

Figure 2 `the gate isshownin its closed position, which isthe position it occupies" when the, push rod is lretracted Las vshown in Figure l. As the push rod 26 is advanc'ed by anC impulse finger 25,-the movement of the link l32 of the .escapement mechanism actuates 'the bell crank 36 through 4the links 37 and 38 and swings the closure -35 in a clockwise direction, as viewed in Figurev 2 and uncovers the passage through the chute 31. 1 l

, The sprocket w` heels 22 and 23 mayy be actuated in any convenient way-by any part of the mechanism employedinthe casting i operation. In the construction shown they lare arranged to be actuated by the move- .ment of ,the part's'in opening the die. Qnf;

the upper sprocket wheel.22 is a ratchet wheel 39 which is engaged bv airatcher, 4U

on the upper end `of an arm 41.-loosely-vpivoted upon the axis of. thegratchetfwheel 22.

This arm 41 extendsdown! into the. gpath of."y

the upper rod` 11 and these parts areA so-related that as the bracket member 10 andthe rods 11 are retracted by the motor,` 19,. the rood 11 which engages thearm 41 will.l swing the arni'around in a clockwise direction actuate the ratchet wheel 39 ya` prede- The weight of the farm 41 will cause it to fall again to a yvertical position when the die is;closed-thus retracty ing the ratchet 40 ,for :another-actuationf' 'f The actuation of the ratchet wheel39- rotates the sprocket wheel 22 a-corres'pondng distance and -hence correspondingly fadvances the sprocketl chain 24. It. isv evident that the number ofactuations lof the arm 41 required to cause lan actuation lofthepush rod 26 depends upon the number of impulse fingers 25. As an illustration, suppose that the pot 30 contains 250 pounds of metal .whenit is ljust full up tothe nozzle opening, C

and that each casting takes 2 ounces of metal and that an ingot weighs 2 pounds. It vis evident that yin 16 casting operations;y 2 pounds ofthe metal will be used 'and if immediately following the 16th casting-oper'- ation a 2 ound ingot is added to the melt'- ing pot, t e metall vwill :have been restored to its former level. Ther impulse ingersl25 will then be sospaced and the throw of the arm 41 will be.. so determined that the fingers 'i 25 will give an impulse to the push-rod26 Aafter every'16 actuations of the arm41. It

the casting should take alittle less than 2 ounces of met`a1,"theny the spacing between the fingers 25 w-illbeV correspondingly Aadju'sted, org-.for instanceyone' 'offfthe vfingers 25 might be-x removed alto'gethe'r""s'o'fask to omit the feeding of. an '.ingotv once yfor v every complete rotation. of thelchain A24.- vSixnilari60 ly` the spacing between the fingers could be adjusted to take care of castings which took slightly more than 2 ounces of metal or for :'.igots which contained a little more or a little less than 2 pounds of metal, or for any other condition which would arise in casting experience.

With a ot of molten metal of suflicient quantity, t e addition of an ingot intermittently inthe manner above described will not ail'ect the temperature of the molten metal materially.4 The oxides and other dross formed by the contact of the air with the surface of the metal will always remain on the top of the metal and by reason of the relatively small diameter of the pot due to its length, the surface attacked by the air is relativelysmall.

It will be understood that the above described1 apparatus is only intended to be illustrative of one way in which my invention may be embodied and that various other ways of carrying out the principle of my invention, as above explained, will readily occur to those skilled in the art withoutdeparting from the spirit of the invention or the scope of the appended claims.

I claim:

1. In a die casting apparatus, in combination with a die support including-two separable clamps, a meltingpot for the casting metal having -a discharge nozzle adapte to feed the molten metal directly to the die, means for delivering ressure fluid on top of the molten metal in t e pot to expel a quantity thereof through the nozzle into the die, means for separating the clamps to o en the die, and means controlled there y for eeding ingots to the melting pot at desired intervals re ative to the operations of the clamp separating means.

2. In a die casting apparatus, in combina- V tion with a die sup ort including two separable clamps, a me ting pot for the castin metal having a discharge nozzle adapte to feed the molten metal directly to the die, means for delivering pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into the die, means for separating the clamps to open the die, means -control d thereby for feeding ingots to the melting pot at desired intervals relative to the operations of the clam se aratin means, and means for varying t e relative frequency of the ingot feeding operations.

3. In a die casting apparatus, in combina- .tion with' a die support, a substantially U- shape melting pot for the casting metal terminating in a discharge nozzle adapted `to feed molten metal directly to a die in the die support, means for delivering pressure fluid on top of the molten'metal in the pot to .expel metal thr'ou h the nozzle, automatic means for intermittently replenishing the masias the delivery of pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into a die in the die support and operating the die clamps to open and close the die, and means controlled by the casting effecting means for automatically feeding ingots to the pot through the pressure fluid end at desired intervals relative to the casting operations. 5. In a die casting apparatus, in combination with a horizontally disposed die support including two se arable clamps, a stationary substantially -shaped melting pot terminating in a discharge nozzle adapted to feed molten metal directly to a die in the die support, means for effecting repeated casting operation including the delivering of ressure fluid on top of the molten metal in t e pot to expel a quantity thereof through the nozzle into a die in the die support and o rating the die clamps to open and close t e die, means controlled by the casting edecting means for'replenishing 'the metal in the pot through the pressure fluid end at desired intervals relative to the casting operations, and means for varying the -relative frequency of the replenishing operations.

6. In a die casting apparatus, in combination with a horizontally disposed die support including two separable clam s, a stationary substantially U-shaped me ting pot terminatin in a discharge nozzle adapted to feed molten metal directly to a die in the die support, means for delivering pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into a die in the die support, means for separating the clamps to open the die, and means controlled by the clamp separating means for feeding ingots to the pot through the pressure fluid end at desired intervals relative to the casting operations.

7. In a die casting apparatus, in combination with a horizontally disposed die support including two separable clamps, a stationary substantially U-shaped melting pot terminatin in a discharge nozzle adapted to feed mo ten metal directly to a die in the die support, means for delivering pressure fluid on top of the molten metal in the pot ingot feeding operations.

8. In a die casting apparatus, in combination with a horizontally disposed die support including two separable clamps, a stationary substantially U-shape melting pot terminating in a discharge nozzle adapted to feed molten metal directly to a die in thedie support and proportioned to contain a large mass of molten metal relative to that required for each casting, means for .delivering pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into a die in the die support, automatic means for feeding ingots to the pot; through the pressure fiuid end, and means'V for controlling the rate of feeding in accordance with the number of casting operations, whereby the level of the metal in the pot is maintained substantially constant.

9. In a die casting apparatus, in combination with a die support includingl separable clamps, a melting pot provided with a discharge nozzle and proportioned to contain a large mass of metal relative to, that required for each casting, means for delivering pressure fluid on top of the molten metal in the pot to expel a quantity thereofl through the nozzle into the die, 4automatic means for feeding ingots to the pot through 'the pressure fluid. end, and means for controlling the rate of f eeding in accordance with the number of cast-ing operations for thereby maintaining the level of the metal in the pot substantially constant.

10. In a die casting apparatus, in combination with a die support including separable clamps, a pressure chamber forming a melting pot for the casting metal provided With a discharge nozzle, means for effecting repeated casting operations including means for delivering pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into the die and operating the clamps to open and close the die, and means controlled by the casting effecting means for automatically feeding ingots to the pot at desiredintervals rela-,- tive to the casting operations.

11. In a die casting apparatus, in combination With a die support including separable clamps, a pressure 4chamber forming a melting pot for the castinf metal provided With a discharge nozzle, means for effecting repeated casting operations including means for delivering pressure fluid on top of the molten metal inthe potito expel a quantity thereof through the nozzle into the die and operating the clamps to open and close the die, means controlled by the casting effecting means for automaticallyT feeding ingots tothe pot at desired intervals relative to the casting operations, and means for varying the relative frequency of the ingot feeding operations.

12. A die casting machine having, in combination, a pressure chamber forming a melting pot for metal to be cast provided with a discharge nozzle, means for delivering pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into a die, and means for feeding ingots to the pot comprising a closure forthe top of the pot operable to open and close the pot, a device operable to 'feed an ingot into the open pot, and means for compelling the operation of said closure and said device in proper timed relation relatively to each other for successively opening the pot, feeding the ingot thereto and closing the pot.

13. A die casting machine having, in combination, a pressure chamber forming a melting pot for metal to be cast provided with a discharge nozzle, means for delivering pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into a die, and means for feeding ingots to the pot comprising a closure for the top of the pot operable to open and close the pot, a device operable to feed an ingot into the open pot, and operating means for assuring and effecting the operation of said closure and said device in timed sequence relatively to each other for successively opening the pot, feeding the ingot thereto and closing the pot, inthe order named.

14. A die casting machine having, in combination, a pressure chamber forming a melting pot for metal to be cast provided with a discharge. nozzle, means for delivering pressure fluid on top of the molten metal in the pot to expel a quant-ity thereof through the nozzle into a die, and a metal-replenishing feed mechanism to feed ingots to the pot automatically at predetermined times .relatively to the cast-ing operations, said feed mechanism comprising a closure for opening and closing the pot at the top thereof, a device adapted to be operated to feed an ingot into the openmt, and means for operating1 the closure an said device in proper time relation relatively to each other and relatively to the casting operations.

15. A die casting machine having, in combination, a pressure chamber forming a melting pot for metal to. be cast provided with a discharge nozzle, means for delivering pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into the die, and a metalreplenishing feed mechanism to feed ingots to the pot automatically at predetermined times relatively to the casting operations,

said feed mechanism comprising a closure icc izo

ice

thereof, a device adapted to be operated to feed an ingot into the oper. pot, and means for operating the closure and said device in proper timed relation relatively to each other and relatively to the casting operations, said operating means including means for varying the frequency of the ingot feeding operations relatively to the casting operations as desired.

16. A die casting machine having, in combination, a pressure chamber forming a meltingr pot for metal to be cast provided with a discharge nozzle, means for effecting relative movement between the pot and a die to and from casting relation, means for deliverin,f r pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into the die, and a metalreplenishing feed mechanism to feed ingots to the pot automatically at predetermined times relatively to the casting operations means controlled by a moving part of thel machine for automatically operatingr said closure and said device at theproper time to open the pot, feed an ingot thereto and close the pot all between the times in which theA die and the pot are in casting,r relation.

17. A. die casting machine having, lin combination, a pressure chamber forming a melting pot for metal to be cast provided with a discharge nozzle, means for effecting relative movement between the pot and a die to and from casting relation, means for delivering pressure fluid on top of the molten metal in the pot to expel a quantity thereof through the nozzle into the die, and a metalreplenishing feed mechanism to feed lingots to the pot automatically at predetermined times relatively to the casting operations and while the pot and the die are out of casting relation, said feed mechanism comprising a closure for the top of the pot operable to' open and close the pot, a device operable to feed an'ingot into the open pot, and means controlled by a moving part of the machine for automatically operating said closure and said device at the proper time to open the pot, feed an ingot thereto and close the pot all between the times in which the die and the pot are in casting relation, said operating means including means for varying the number of ingot feeding operations relatively to the number of casting operations.

18. A die casting machine having, in combination, a pressure chamber forming a melting pot for metal to be cast provided with a discharge nozzle and a metalreplenishing feed mechanism operated automatically in proper timed relation to the casting operations to feed ingots to the pot at predetermined times relatively to the casting operations.

19. A die casting machine having, in combination, a pressure chamber forming a melting pot for metal to be cast provided with a discharge nozzle, and a metalreplenishing feed mechanism operated automatically in proper timed relation to the casting operations to feed ingots to the pot at predetermined times relatively to the casting operations, said feed mechanism including means for varying the number of ingot feeding operations relatively to the number of casting operations.

20. A die casting machine having, in combination, a pressure chamber forming a melting pot for metal to be cast provided with a discharge nozzle, and a metal-replenishing feed mechanism operated automatically in proper timed relation to the casting operations to feed ingots to the pot at predetermined times relatively to the casting operations, said feed mechanism comprising an ingot-feeding device adapted when operated to feed an ingot to the pot, means for operating the ingot-feeding device including a lug carrier the lugs of which control the operations of said device, means for automatically advancing the lug carrier a step at each casting operation, and settable lugs adapted to be set to different positions on the lug carrier for causing the ingot-feeding device to be operated at predetermined casting operations only and whereby the frequency of the ingot feeding operations relatively to the casting operations may be varied as desired.

scribe my l signature.

CHARLES PILCK.

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