US1514103A - Typographical casting method and apparatus - Google Patents

Description

ov., 4f. ma@ f www3 J. R. ROGERS TYPOGRAPHICAL CASTING METHOD AND APPARATUS Filed Sept. 24, 1920 3 Sheets-Sheet. l

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Nov. 4. l924 1,514,163

J. R. ROGERS Y TYPOGRAPHICAL CASTING METHOD AND APPARATUS Filed Sepf. 24, 1920 5 Sheets-Sheet 2 LSMB Nov@ 4, @2%

J. R. ROGERS TYPOGRAPHICAL CASTING METHOD AND APPARATUS 3 Sheets-Sheet 5 Filed Sept. 24, 1920 TTORNE YS m T. A IL l N y K ffm/@k MTNESS'EAS l Patented New. 4g?, Il @24 .ronN' n apenas, or BnooxL-YN, New Yoan, assIeNoa :ro NnnenNTHALna LINO- rxrn COMPANY, A conronarIoN or Naw *zo i:

'GBAJPHICAL CASTING METHOD AND APP :s =v

Application led September 24, 1.920. `Serial No. 412,548.

To all, wle/0m t may concern: Y

Be it known that I, JOHN R. ROGERS, a'

ranged to deliver molten metal into a slotted t moldv and up against a composed line o;

matricesto produce a type bar or slug bearing on its edge type characters correspondingl to the intaglio characters of the matrices. In these machines, the molten metal isiintroduced into the mold by means'o'f a spring-actuatedl pumppiston vor plunger arranged within 'the-poltfalld controlled in `its actionA by a rotary cam which, as Welli known, makes one complete rotation foreach cycle of operation of the machine. The cam is so shaped as normally to maintain the pump plunger in a raisedposition out of action, hut at one point in its circumference, it is formed with a depression which, at fthe properl time, permits the plunger to descend more or less gradually and uniformly under the influence of its actuating spring 'to ill the mold with molten casting operation. This old arrangement is entirely satisfactory and elicient for the production of lslugs of ordinary sizes, say

up to 18 pt. orI thereabouts, but it has notbeen found tobe so satisfactory or eilicient in machines of more recent develo ment, which provideV for the production o slugs of much larger sizes, extending up to 36 pt. and above. For instance, in casting slugs of these larger sizes, it frequently halpens that becausey of imperfections many o he slugs must be recast'one o r more times before they are at all suitable for use; infact, it is seldom attempted to make use ospch slugs for high-grade work. The more serions imperfections are present in the type characters, which'otten appear in ragged or porous condition, due to the incomp ete filling of the matrix cavities and the formaate metal for the tion 'of air pockets, etc. These and other objections may be explained partly by the fact that the pump plunger'fails to exert sufficient pressure upon the molten metal to drive it with the requisite force into the Amatrix cavities or to expel the air completely from the mold. Indeed, near the. completion of the casting operation, the load applied to the plunger which should be at its maximum) is actual y at its minimum, due to the lost tension or relaxation of the actuating spring at that time. There are many other diculties that might be mentioned, but it would serve no` to discuss the matter further.

My invention is 'intended to`-overcome the foregoing objections and aims to produce slu of all sizes in practically perfect condition. To this end, specifically, I propose to cast the larger sized slugs by filling the mold with -molten metal under the action useful purpose of-two distinct impelling forces of diierent relative intensities and applied respectively at different periods in the casting o eration. The first force (of lesserintensi-t l) is applied more or less slowly an gradually, acts to introduce the molten metal into which the mold at a corresponding rate of flow,`

while the second 4force (of greater intensity), which is applied more quickly and albrutly than the first, 'acts to accelerate t e pletion of the casting operation. Actual practice has shown that a slug produced .in this Away is lpractically perfect and particularly as regards its type characters, which are sharply andv clearly dened and conform ow of metal and to subject the metal to a sudden, heavy pressure near the com in the minutestdetail to the coniiguration of the matrix cavities and whose printing faces are entirely free frompores or other im erfections. f

y invention also contemplates an improved form of a paratus for carrying out the foregoing casting method in the re lar linotype machine, and this incidental y by making as little change as possible in -the existing parts oi such machine. In the preferred embodiment herein illustrated, such apparatus comprises two distinct pump pistons or plungers arranged within the lmelting pot and operated one after the other in the casting operation to torce the molten metal into the mold in the required manner.

y The exact construction and operation of parts will best be understood from the detailed description to follow.

Referring to the drawings:

Fig. 1 is a vertical section taken through the casting mechanism of ka linotype machine having my invention embodied there- Figs. 2 and 3 are similar views, showing the arts in dierent relative positions;

Fig. 3a is a section taken on the line 3, 3 of Fig. 3; and

Fig. 4 is a plan view of the devices shown iii Fig. 1.

In Fig. 1, the parts are shown iii the relative positions they occupy just prior to the commencement of the castin operation. In this condition of the parts, t e slotted mold A, carried by the rotary'disk A1, is closed at the front by the" composed line of matrices X presented momentarily thereto by the vertically movable first elevator B, and it is closed at the rea-r by the mouthpiece C1 of the melting pot C sustained within the rocking frame or jacket D. The pot C, which contains a supply of type metal maintained in a molten condition by means of a suitable burner (not shown) is formed with a throat or passage C2 through which the molten metal is forced into the mold during the casting operation. The foregoing parts are of ordinary construction and operate in the well known manner.

W'hile my new method of casting mightbe carried out by various means, I have hereinprovided an improved form of pumping apparatus specially adapted for that purpose, which apparatus in the preferred embodiment illustrated comprises two distinct pistons or plungers E and F arranged to reciprocate within separate wells or cylinders E1 and'F1, both communicating with the discharge throat or passage C2 and the former` having a port opening e for the admission of molten metal thereto.

The plungerE is substantially of the saine dimensions as heretofore and is connected by means ,of a rod or link E2 to the free end of a vertically movable lever E2, which latter is formedat its opposite end with a bearing sleeve E* mounted loosely on a fixed transverse rod Els of the machine frame. The sleeve E4 is provided with two arms Ea and E', the former carrying a roller E8 which is arranged to track upon the periphery of `the usual rotary cam E2 fast to the main shaft E1 lof the machine, and the latter being extended laterally beneath a further lever E11 which -is also mounted loosely on the fixed rod E and has -its free end connected to a tension. spring E12 pullinoi downwardly thereon from a fixed part of the machine. As wellj understood, the peripheral face of the cam E9 is concentric throughout except at one portion of its circumference, where itis cut away or formed with a depression to provide the customary sloping surfaces E1'1 and E15. When the machine is at rest, the roller E8 is in contact with the concentric portion of the cam E", so that the plunger Eis maintained in its raised or. inoperative position, as indicated in' Fig. 1. This condition obtains until the castin period arrives, when the cam (rotating in the direction of the arrow) brings its sloping surface E15 into engagement with the roller E8, which then descends along suchsurface to the bottom of the depression, thus permittin the spring E12, through theconnections escribed, to depress the plunger E and force a charge of molten metal into the mold. As the cam continues to rotate, the roller Es is engaged sooner or later by the 'sloping surface E14 and the parts thereby restored to and maintained in their original conditionl to await the next casting operation.

Referring now to the second plunger F, it is connected by means of a rod or link F2 to a vertically movable lever F3' pivotally mounted on the 'fixed rod E5 alongside of the lever E3 and constantly ur ed downward by a compression Spring F4 o substantially the same strengthas the spring E12 and which acts on thelever F3 through the sliding rod.

F5. This lever F3 normally rests upon a supporting piece YF6 projecting laterally from the lever E3 and is thereby maintained in its raised or inoperative position indirectly by the cam E9. It is apparent, therefore, that in the absence of some means to prevent it, the plunger F would be raised and lowered simultaneousl with the plunger E under the influence of tllie cam E9. However, and as before'intimated, I propose to actuate the two plungers at different periods in the 'casting operation, and means are therefore provided to delay the operation of the plunger F until the plunger E nears the end of its full pumping stroke. In the present instance, such means comprise a locking pawl the ,side of the lever F3. Adjacent its pivotal i point the pawl F7 is formed with right-angular y disposed arms F11, against which bear a pair of set screws F12 carried b an operating lever F1s also loosely mounte on the iixed rod F8. At its rear end, thelever F13 is provided with a roller F1* adapted to be engaged by the rotary cam E9, at the proper time to trip the pawl F1. If desired, the pawl F7 and its operating lever F13 may be made integral, but it isr preferred to make them relatively adjustable by some such means as described, so that. the tripping of the locking pawl by the rotary cam may be varied or controlled as desired.

The operation of the pump -plunger F is as follows: When the macliineis at rest or iio ieu

during the rotation of the cam E preceding -the casting operation, theroller E1* tracks upon ythe concentric portion ofthe cam, ywhich therefore maintains the locking de- 5 tent F7 disengaged from the operating lever F3, leaving' the latter to be supported by the operatm lever E3 in the manner before described. ing the casting operation, the rollel` F1" becomes momentarily disengaged from the cam E", due to the presence of the depression therein,l and hence allows the operating lever F13 to'fall by gravity and rock the detent F 7 to locking position (Fig. 1). Con- 15 sequently, when the lever E3 is subsequently rocked downwardly by its actuating spring E12 to operate the pump plunger E as before described, the detent F7 serves to support the lever F3 and the attached plunger F in their raised condition 2). But the support thus furnished Yby the detent F7 is only momentary, as almost immediately the roller F14 again passes onto the concentric and highest portion of the rotary cam E, which then lifts the operating arm F15 and withdraws the detent F 7 from engagement with the operating lever F3 (Fig. 3). This withdrawal of the detent F7 instantly releases the' actuating spring Ft, whose full load is immediately applied to the plunger iF to complete the casting operation. As before noted, the tripping of the pawl, Ft to release the spring F* is timed to take place just beorethe plunger E completes its full downwardstroke, see Fig. 2. The parts vare finally restored to their original condition by the continued rotation of the cam F9, which acts indirectly through the lever E1? and its rojecting piece F8 to return the 4lever F3 and) the attached lunger to their raised position, when t e machine completes its cycle of operation and again comes to rest. f p lt will be noted that the action of the plunger E takes place more or less slowly and gradually, due to the engagement of the roller F8 with the sloping cam surface E15; whereas, the action ot the lunger F is more rapid and abrupt, due to t e absence of any such restraining induence. This arran ement has been devised not only to provide for the later operation of the plunger F, but also to enable it to exert a sudden hammerblow ei'ect u on the molten metal at or near the completlon of the casting operation. While such a 'di'erence in operation of the two p lun ers might be suiiiclent under certain con itions to accomplish the desired results, the parts are otherwise constructed 0 and arranged so that the di'erence in force of the respective plungers in actin u n the metal will be more pronounced an e ective. Thus, as shown, the diameter of the plunger F or its well F1 is considerably less than @5 that of the plunger F or its Well E1. As a owever, ,immediately preced- Y result, and since the two actuating springs F1 and E12 are ofv substantially the same strength, it necessarily follows that the smaller plunger F is capable of exerting a pressure greatly in excess of that in' the case of the lunger E, due of course to their dii'erent efigctive areas which vary accordingly to the square of the diameter. As' a matter of fact however, the diHerence in pressure is even greater because ofthe more rapid and abrupt action of the smaller plunger. lt may be remarked in passing.

that the inertia of the plunger E is nite sufiicient to enable it to withstand the iffh -pressure developed by the 1plunger F for the rief period during whic such pressure is maintained.

It will now be clear that, in the operation of my improved apparatus, the two pump plungers act upon the molten metal with dierent relative intensities, the plunger E in its earlier operation serving to introduce molten metal into the mold at a 'ven rateo ilow, and the plunger F inv its later operation serving to accelerate said dow of metal near the completion of the casting operation as well as to subject the owing' metal to aY suddenly applied pressure at that time. 0r stated diferently, the plunger E acts first to introduce a char e of molten metal into the mold which is su stantially lled thereby, while the plunger F acts subsequently to subject said charge before it hardens or solidies to the required pressure, which as above noted is much greater than that capable of being exerted by the plunger E actin alone. ln a Sense, therefore, the plunger is a charging-medium, and the plunger F a pressure-medium, although the latter will, if need be, assist in introducing any further metal necessary to till the mold completely. Thus, as indicated in Fig. 3, the extent of descent of the plunger F 1s very sli ht as compared with that of the plunger Eg, and hence, considering the small area of the operative face of the plunger F, the volume of metal displaced by it is comparatively small. Of course, `if desired, the plunger F could be made to displace a greater uantity of metal,

but it is preferred to emp oy it essentially as a pressure medium as herein, so that as much ressure as possible may he exerted upon tlie molten metal near the completion of the casting operation. v

By casting the slugs in the foregoing manner, not only is the complete lling of the mold and the expulsion of all air therefrom positivel insured, but, in addition, the molten meta while still in a luid state, or before it has had a chance to cool or harden, is driven forcibly and certainly linto every ortion of the matrix cavities and then hel there under intense pressure, although only for a moment, until solidiiication takes place. It

has been found that slugs as thus produced arev satisfactory in every respect and entirely free from the many imperfections so common in the past. The type characters,

in particular, are complete, clear and well defined, and present a hard, even, solid print` ing face suitable for the highest grade 'of work. A Indeed, for all practical purposes, the slugs may be said to be perfect, or as nearly so as it is practicable to make them by castin It will Iiave been understood that the forel going description deals only with the production of slugs of the larger sizes. For

slugs of the smaller or ordinary sizes, it vis.

not necessary, (in fact, it might be dangerous) to make .use of thc second pump plunger F in the casting4 operation. For this reason, I have provided means whereby'the plunger F may be rendered inactive when desired. As asimple'and convenient way to accomplish such result, the operating lever F13 for the locking pawl F7 is provided with a pivoted section F15 wherein the rollerl F14 is journalled and which is normally held in operative position by a removable pin or stud F1". By removin this pin F1,

from different melting 'pots or different com- -the pivoted section F15 may e swung upsatisfactory and'etlicient for the production` of slugsor ordinary sizes, which do not require the intense pressure so desirable in con-` nection with the larger sized slugs.

I have herein shown my improved apparatus merely in referred form and by way of example, an obviously man changes and variations may be made therein without departing from ther spirit of my invention. For instance, in lieu of their present-Aarran ement, the two pump plungers might be ma e to force the molten metal into the mold partments of the same pot. Or, instead of arranging the plungers side by side in the pot as herein shown, they might be fitted one within the other, in which case the interior bore ofthe outer plunger` would act as the well or cylinder for the inner plunger. As a matter of fact, in the broader aspects of my invention, the smaller plunger might be dispensed with entirely and some other means em loyed for treating the molten metal in t e manner above described. In short, many modifications and 4alterations will readily suggest themselves to those skilled in the art without departure from the scope.of my invention. v

It should also be 'understood that my im# j proved method of castin y slugs may be carried f out by meanso other apparati'is 70 than that herein disclosed, and quite irrespective vof whether or not'such apparatus is capable of being employed in the regular linotype'machine. In fact, my'invention in this respect contemplates any form of appaff' ratus capable of carrying out the novel method of casting set forth in the particular claims directed thereto. Having thus described my invention, its A construction and mode of operation, what .80 I claim is as follows:

1.vInv i a typographical casting ymachine,

`thecombination of a mold, and mechanism for introducing molten metal into the mold at a given rate of flow andsfor accelerating Abut maintaining said iow of metal nearthe completion of the casting operation.

2. In a typographical casting machine,Y the combination of a mold, andmechanisin for introducing molten metal -into the mold at a given rate of flow and for applying af sudden pressure to the flowingmetal near the completion ofthe casting operation while maintainingsaid flow.

3. In a typographical castingmachine, the combination ofa mold, and mechanism for filling the mold with molten metal,l said mechanism including two distinct intermittently actuated impelling means acting respectively u n the molten metal at different 10o periods in t e castin operation while maintaining the dow o metal into the mold from the'source of supply.

4. In'- a typographical casting machine,

the combination of a mold, and mechanism i for filling the mold with molten metal, said mechanism including two distinct impelling means of different relative intensities actin respectively upon the molten metal at di ferent periods in the casting operation while maintaining the low of metal into the mold from the source of supply. p

5. In a typographical casting machine, the combination of a mold, and mechanism for lling the mold with molten metal, said mechanism including two distinct impelling means acting respectively upon .the molten metal at different periods in the casting v operation, the second more. quickly and' abruptly than the first while maintaining `the ow of metal into the mold from the Asource of supply.

before it is allowed to harden or solidify while 'maintaining the flow of metal into the molfl from the source of supply.

7. In a' typographical casting machine, the combination of a mold, means operated at one period in the casting operation to introduce a charge of molten metal into the mold, ano'. separate means operated at a later period in the casting operation to subject said charge to the required pressure before it is allowed to harden or solidify while maintaining the flow of metal into the mold from the source of supply.

8. In a typographical casting machine, the combination of a mold, and a pumping apparatus for filling the mold with molten metal, said apparatus comprising two plungers operated at dierent periods in the casting operation while maintainngthe flow of metal into the mold from the source `of supply.

9. In a typographical casting machine, the combination of a mold, and a pumping apparatus for filling the mold with ,molten metal, said apparatus comprising two plungers operated at dierent periods in the casting operation and acting upon the molten metal ywith different relative intensities in the successive periods while maintaining the flow of metal into the mold from the source of supply.

10. In a typographical casting machine, the combination of a mold, and intermittently actuated pumping apparatus for filling theY mold with vmolten metal, said apparatus comprising two plungers, one acting to introduce a charge of molten metal into the mold, and the otherto subject said charge to a predetermined pressure before itis allowed to harden or solidify while maintaining the flow of metal into the mold from the source of supply.

11. In a typographical casting` machine, the combination of a mold, and a pumping apparatus for filling the mold with molten metal, said apparatus comprising two plungers, one operated more quickly and abruptly than the other and both actingv upon the molten metal while the mold is in communication with the source of supply.

12. In a typographical casting machine, the combination of a mold, and a pumping apparatus for filling the mold with molten metal, said apparatus comprising two plungers having operative faces of dii'erent areas, and both acting upon the molten metal while the mold is in communication with the source of supply.

13. In a typographical casting machine, the combination of a mold, and a pumping apparatus for filling the mold with molten metal, said apparatus comprisin two plungers having operative faces of dierent areas and operated at diierent periods in the casting operation, both of said plungers acting upon the molten metal while the mold is1 in communication with the source of sup- P y' 14. In a typographical casting machine, the combination of a mold, a pumping apparatus for illin the mold with molten metal and comprising two plungers operated at different periods in the casting operation, and means for renderinof one of said plungers inactive when desired.

15. In a typographical casting machine, the combination of a mold, a pumping apparatus for filling the mold with molten metal and comprising two plungcrs having operative 'faces ofv dierent areas, and means for rendering the smaller plunger inactive when desired. Y f

16. In a typographical casting machine, the'v combination of a mold, a pumping apparatus. for lling the lmold with molten metal 'and comprising two lungers, one operated more quickly and abruptly than the other, and means for rendering the more quicily operated plunger inactive when desire 17. In a typographical casting machine, the combination of a mold, a pumping apparatus for filling the 'mold with molten metal and comprising two plungers operated at different periods in the casting operation, and adjusting means for varying the interval between the operation of the two plungers as desired.

18. In a typographical casting machine, the combination of a melting pot formed with a discharge throat and with two pump wells each directly communicating with said throat, a pump plunger arranged within each of said wells, and intermittently actuated means for operating both of said A plungers in the casting operation.

1Q. In a typographical casting machine,

the ycombination of a melting pot formed f with a discharge throat and with two pump wells communicating with said throat, a pump plunger arranged within'each of said wells, and intermittently actuated means for operating said plungers one after the other in the casting operation.

20. In a typographical casting machine, the combination of a melting pot formed. with a discharge throat and with two pump wells of di'erent cross sectional areas each directly communicating with said throat,- a: pump plunger in each of said wells, and m for operating both of said plungers in the casting operation. i

21. In a typographical casting machine,

- the combination of a meltingpot formed with a discharge throat and with two pump wells of dierent cross sectional areas communicating withsaid throat, a pump plum ger fitted in each of said wells, and means for operating said plungers one after the other in the casting operation.

22. In a typographical casting machine, the combination of a melting pot formed' with a discharge throat .and with two pump wells each communicating with said throat, a pump plunger arranged within each of said wells, means for operating both of said plungers in the casting operation, and means for rendering one of said plungers inactive when desired. y

23. In a typographical casting machine,

fthe combination of a melting pot formed with a discharge throat and with two pump wells communicating with said throat, a pump plunger arranged within each of said wells, means for operating said plungers operating both of said plungers in the casting operation, and means for rendering the smaller plunger inactive when desired.

25. In a typographical casting machine, the combination of 'a melting ot formed with a discharge throat and with two pump wells communicating with said throat, a pump plunger arranged within each of said wells, and means for operating both of said plungers in the. casting operation but one more quickly land abruptly than the other.

26. In a typographical casting machine, the combination of a melting pot formed with a discharge throat and with two pump wells commumcating with said throat, a pump plunger arranged within each of said wells, meansfor operating both of said plungers in the casting'operation but one more quickly and abruptly than the other, and means forI rendering the more quickly operated pump inactive when desired.

27.111 a typographical casting machine, the combination of a meltingpot formed with a. discharge throat and with two pump wells communicating with said throat, a pump plunger arranged Within each of said wells, means for operating said plungers one after the other in the casting operation, and adjusting devices to vary the interval between the operation of the two plungers as` desired. p

28. In a typographical casting machine, the combinatlon of two pump plungers, and 'means for operating said plungers one after the other 1n the casting operation, ,said means including'two spring-actuated levers connected to the respective plungers, a.- rotary cam which directly controls the operation of one of said levers, and intermediate devices through which said cam indirectly controls the operation of the other of said levers.

29.' In a typographical casting machine,

I 30. In' a typographical casting machine,

the combination of two pump plungers, `and means for operating said plungers one after the other in the casting operation, said means including two spring-actuated levers connected to the respective plungers and one p.,

arranged to give support to the other-*When the two occupy their inoperative positions, a rotary cam cooperating with one of said levers and formed with a depression to permit the operation thereof at the proper time, and

a locking detent acting under the control `of the cam to hold the other ofsaid levers momentarily in its inoperative position after the first mentioned lever has begun its operation.

31. In a typographical casting machine, the combination of two pump plungers, and means for operating said plungers one after the other in the` casting operation, said means including two spring actuated levers connected to the respective x .plungers, a ro-` tary cam controlling theoperation of one of said levers, a locking detent serving normally to hold the other of said levers out of actlon, an operating lever acting under the control of the rotary cam to disengage the lookin detent at a predetermined period, and a justable connections between the locking detent and its operating lever for varying the period of disengagement of the former b the latter.

.33. a typographical casting machine, the combination of two pump plungers, and means for operating said plungers one after the other 1n the casting operation, said means including two springI actuated levers connected to the respective plungers, a rotary cam controlling the operation of one of means including two spring actuated levers im said levers, a locking detent serving normal- 'ly to holdthe other of said levers dut of action, and an operating lever acting under the control of the rotary cam to disengage the locking detent at a predetermined period, said operating leverv being provided with a pivoted section arranged to be moved beyond the control of the rotary cam to allow the locking detent to remain active throughout the casting operation.

34. In a typographical casting machine, the combination of a mold, a melting pot formed with a single discharge throat, two 'pump plungers,-arranged with said pot and acting to force the molten metal through the single discharge throat into the mold, and intermittently actuated mea-ns for operating both of said plungers in the casting operation.

35. An improvement in the art of type casting, which consists in introducing molten metal into the mold at a. given rate of flow, and accelerating but maintaining said flow of metal near' the `completion of the casting operation.

36. An improvement in the art of type casting, which consists in introducing molten metal into the mold at a given rate of flow, and subjecting the owing metal to a suddenly applied pressure near the completion of the casting operation while main.

taining said l'low.

37. An improvement in the art of type casting, which consists in filling the mold` with molten metal under the action of two distinct impelling forces applied respectively at different periods in the casting operation while maintaining the iow of Iretal into the mold from the source of sup- P Y- 38. An improvement in the .art of type casting, which consists in filling the mold with molten metal under the action oftwol distinct impelling forces of different relative intensities applied respectively at different periods in the casting operation while maintaining the flow of metal into the mold from the source. of supply..

39. An improvement in the art of type casting, which consists in filling the mold with molten metal under the action of two distinct impelling forces applied respectively at different periods in the casting operation, the second force being applied more quickly and abruptly than the -irst while maintaining the owfof metal into the mold from the source-of suppl I.

,40.v In a typographical mac ine, a metal pot having a plurality of pumps and constructed for the delivery of molten metal therefrom to the type casting molds, and means for cutting off the delivery of metal from one of said pumps at the will of the operator. .Y

41. In a typographical machine, a. metal pot constructed for the delivery of molten metal `to the type casting mold and having a plurality of metal injecting plungers, and means under the` control of the operator whereby one of said pumps may operate independently or a plurality of them may operate concurrently, asl desired.

42. In a typographical machine, a metal pot constructed for the'delivery of molten metal to the type casting mold and having a pair of metal injecting plungers, actuat# ing means common to loothl plungers, means operative with one of said plungers to cause concurrent operation with the other plun-I ger, and means orrestraihing the first mentioned plunger from operation during the operation of the latter mentioned plunger.

43. In' a typographical machine, a meta] pot constructed for the delivery of molten metal to the type casting mold. and having a pair of metal injecting plungers, actuating means common to both plungers, and means for preventing the operation of one of said plungers orpermitting the concilrrent operation of both, as desired.

44. In a typographical machine, aimetal lpot constructed for the delivery of -molten metal to the type-casting mold and having a pair of metal injecting plungers, a corresponding pair ofspring actuated levers connected tothe respective plungers, and a rotary cam cooperating directl y with one of said levers and through `it with the other of said levens to control the operation of the metal injecting plungers.

45. In atypographical machine, a met'al pot constructedfor the delivery of molten metal to the type casting'-I mold and having a pair of metal injecting plungers,'a corl responding pairof spring actuated levers connected to the respective plungers, a

rotar cam cooperating directly with one of said levers and through it with the other of Vsaid levers to control the operation of the metal injectin plungers,'and means for locking the secon mentioned lever against operation, when desired, to permit' the independent operation of the first mentioned InI testimony whereof, I have allixed'my signature hereto.

JOHN R. ROGERS.

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