US526874A - And eugene c - Google Patents

Description

. (No Model.) y n J. J. o. ,an 5.o. SMITH. f APPARATUS POR CASTING METALS UNDER PNBUMATIG PRESSURE.

No. 526,874. A Patented Oct. 2, 1894.

I ,I'IED STATES JOHN J. C. SMITH, OF

PATENT OFFICE.

APPARATUS l-'ORCASTlNG METALS UNDER PNEUMATIC PRESSURE.

SPECIFICATION forming part of Letters Patent No. 526,874, dated October 2, 1894.

Application tiled January 10, 1894:- Serial No. 496,401. (No model.) Y

T0 all whom t may concern.-

Beit known that we, JOHN JOSEPH CHARLES SMITH, residing at Passaic, county of Passaic, State of New Jersey, and EUGENE C. SMITH, residing at Providence, county of Providence, State of Rhode Island, citizens of the United States, have invented certain new and useful Improvements in Apparatus forQasting Metals under Pneumatic Pressure, of which the followingis a specification. y

The object of the invention is the construction of a practical aparatus into which molds that are to be filled with metal may beinclosed hermetically and air tight so that a high vacuum may be obtained.v in the molds and'so as not to involve waste of time and labor.

In making our apparatus We reflected particularly on a new,useful and practical combination and arrangement of the different parts so as to serve their functions to the best advantage, save labor and produce results to a certainty. I

Experience gained by long :and practical use of casting machines constructed'differ'- ently from our new one has shown us many great deficienciesinthem. Castingapparatus -by means of which mechanical pressure is ap# plied to the fluid metal to force vit in the molds,require very dense and strong Vmolds and even with such the molds crack from the sudden heat and force of the metal which only too often will show objectionable tins or seamson the casting if the casting is not spoiled altogether. Furthermore, `such .for mer casting machines have been constructed to receive a number of molds for every casting operation because the charging, closing and the getting of the machine ready for a casting, take so much labor onaccount of the Wrong combinations of the different parts.

' To ll a number ofl molds, each probably containing tive toten pieces, generally results in a loss of several pieces-sometimes half of them. Furthermore, when a number of molds, say only two, are placed for one charge in the machine, it very often happens that the fluid metal will force or bend one mold into the hollow part of the other, which increases the thickness of one casting and di@ minishes the other opposite one. This is a packing on a part of the machine.

very objectionable feature especially on light and very thin articles. Therefore, we aimed inthe construction of our new machine toarrange every part so that the machine can be charged, closed, and discharged in the least time possible, so that Vwe need not castor fill more than one mold at every operation and cando so with comparatively little Work or loss of time.

Practice in casting by means of machines made for application of mechanical pressure has taught that if molds are made of a material which has not enough density to resist the pressure of the iiuid metal, the castings will not present such a smooth surface and such sharpness of lines as the mold really presents.' Our new casting apparatus is designed to use to better advantage molds Which can fbe made by the method, and of the composition described in application of Eugene C. Smith, Serial No. 456,915, tiled December 3l, 1892. Molds made by that method are veryv perfect but the strength of the material is not great enough to resist the mechanical pressure applied to the fluid metal.

Mechanical pressure cannot be regulated to a nicety ou account of the friction inthe cylinder,y but atmospheric pressure can be regulated to the exact required pressure to be exercised on the metal. To obtaina perfectly sharp and smooth casting by a vacuum only requires a fine but Very porous mold.

Referring to the accompanying drawings which form a part of this specicationzFig ure I represents a vertical longitudinal section of the machine through the center. II is an elevationof the front. Figs. III and flV Vare respectively plan and sectional views of an angular rubber rim used as an air-tight Fig. V is a plan of an asbestos washer also used as a Iireproof packing.' Figs. VI and VII are respectvely a vertical section and a plan of an` asbestos tube, washer or ring used to line the Vmain gate.

Fig.

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or T-slot R2 in its center to receive a sliding bolt R3. To the plate B, two side plates C are connected by means of hinges D so that the side plates will open or close like doors. Each of said two plates has angular extensions at the loose edge slotted to form hooks C2. With an upright movable plate E, the base A, the upright B and the two side plates C, a box or case is formed which has a given height and width. By moving the plate E either forward or backward the depth of the box may be increased or diminished. The adjustment of the plate E is facilitated by the attachment of an arm F which has a ro1lerF2 at the end, the same resting on the base A. 'Ihe arm F prevents also the falling of plate E. The top or cover of this box is formed by a plate G which is hinged at M to the upper end of plate E. The plate G reaches over the horizontal extension B. By means of the slot bolt R3, the top plate G can be fastened to the extension R at any desired place. As the `plate G is fastened to plate E by means of hinge M, it is evident that the depth of the box (i. e., the distance between plates B and E) can be increased or diminished as it may be required according to the thickness of the mold to be placed in the box for casting. The plate G can also be thrown `back on its hingeso as to open the box on top.

When a mold Z is placed in the box to be filled with metal it is placed against the plate B. The plate E is then `moved against the mold and by means of the screws J 'which have their fulcra in two removable crossbars X, the mold can be held togetherrmly.

The cross bars X are provided with angular hooks X2 at the end `and serve also by means of the hooks X2 `to hold or lock the sides C firmly to the edges of plate E.

By the arrangement and combination of the parts so far described a rrn case or mold box is'formed which can be opened and closed in less than a minute. On top of the plate G is a funnel-shaped metal receptacle K. It is attached to theplate G by means of a swivel bolt N and a lock bolt K2. This metal receptacle has an arm or extension K3 on one side and a hinge joint L on the other. One-part of the hinge joint L is formed by an attachment to the swivel joint N. At the end of the hinge joint L is `an upright post T to which a cross bar or lever P s'hinged` at Q, forming a joint at thatpoint. At the center point where the lever `P crosses the metal receptacle K is a vertical stem 0,'jointed`t`o lever P at that place. This vertical stem O is almost seven-eighths of an inch thick and has an asbestos covering O2. The metalreceptacle, when thrown upward on its hinge L, is open at the narrow end. The receptacle is provided with an `asbestos lining K on the inside. The bottom "of the receptacle is formed by plate G when the `receptacle is resting thereon. j

Bymeans of a hole S through the plate G, at the center of the receptacle communication is established from the receptacle to the interior of the case and molds inclosed therein for casting. The diameter of the hole S is almost one-eighth of an inch smaller than the diameter of the stem O so that the stem will fully cover the hole when resting on it, and for centering the stem it may have a slight boss at its lower end to enter the hole S. An asbestos washer S2 almost one-sixteenth of an inch thick and about one-twelfth larger than the inside of the receptacle at its narrow end is interposed between the plate G and the edge of the narrow end of the receptacle. The hole in said washer is of the same size as the hole S in plate G. When the washer is in position, the hole in it must coincide with the hole S in plate G. The hole S is lined with a vshort tube or ring S3 of asbestos of the shape shown in Fig. VII. One edge of said ring has a little ilange S4 to prevent it from slipping through the hole. The flange of short tube S3 serves alsoas a good air tight junction with the hole in the washer', when the stem O rests over it.

We have to describe how we 'render the case perfectly air tight so that the required vacuum can be created in the molds inclosed in the case. On the three (top and side) edges of the upright plate B we embed anarrow rubber packing strip Y (a litt-1e more than semi-circular in cross-section). The flat surface of the packing strip projects about--one-sixteenth of an inch over the surface of the edges of the plate. A similar packing strip Y is also embedded on the top edge of the plate E but not at the side edges or the bottom edge of said plate. Those three edges are provided with a dierent style of packing which is done as will now be described. To theouter surface of plate E we attach `near the edges a rubber rim of the angular shape shown by plan'and cross- 'section in Figs. III and IV'. This rubber packing rim E2 is of the exacts-izo of plate E but the angular edges Hare outa little as shown by the drawings. The side plates or doors C being hinged to upright plate B, if closed, will press against the rubber packing at the edges of plate B and when locked by the cross bars :c press also againstthe flaring flanges of thefrubber rim E2. The lower flange of rubber rim E2 formsagood junction with the platformor base A. Theadoption of `this peculiar shaped `packing rim E2 is for this reason. The plate E has to bemoved a little forward yet by means of screws J after the sides O are locked so as to press the two halves 'of the `inold firmly together, but if a similar packing to that on the edges of plate B `were used the'plate Elcouldnot bemoved after the box is locked. When a vacuum is created in the case the pressure of the atmosphere will act on the flanges of the rim and close the corners hermetically. When the top plate G is brought downto close the'top the case is alreadyfrmly locked and no further moving of the lower parts `takes place.

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Therefore the top edges of plates E and B are also closed air tight by the packing at those two edges. So far the hermetical closing yof the mold case is automatic and requires no special time or labor. Only the top and bottom edges of the two side plates or doors C remain to be sealed which we prefer to do at every operation of casting by luting those joints with plastic clay or soft putty as we have found in practice that rubber packings at those junctures are not very reliable. This lu ting up'is done very quickly and effectively. It :is shown that the base A is a little wider than the bdy of thevmachine and when the doors C are closed a sharp corner C4 is formed which is quickly sealed by smearing a little clay or putty in that corner. A similar corner C3 is formed by the edges of the plate G and the upper edges of the plates C which is also luted in the same manner.

The hole S in the top plate G is hermetically closed by the stem O resting over said hole on top of the flange of the lining ring S2. The lower edge of the metal receptacle finds an air tight packing by pressing on the outer edge of the washer S3. A Weight W at the end of lever P holds the valve stem down firmly. Y y

From the description so far given our new apparatus Apresents a seriesof novel and useful combinations for the purpose of saving labor and time.

First. The case or box for receiving the molds is so constructed that by the novel combination of the dierent and required parts, it may be closed hermetically with the greatest facility and effect, so that a good vacuum can be produced in the molds.

Second. The upper part of the apparatus consisting of the metal receptacle with its closing valve is so constructed by a new combination of the required parts that it can be quickly adjusted to receive a charge of metal and hold the same against the suction of the Vacuum until the proper moment when the metal is .allowed to ow into the molds. After a cast is, made the receptacle can be detached easily and quickly from the casting and the remaining surplus of metal discharged. y t

The apparatus is operated as follows: The molds that we use are made of thecomposition and in the manner described in the specification of Eugene C. Smiths application above cited. The molds are made of the exact size of theinside of the case in height and width. The 'thickness or depth of the mold however depends on the shape of thel casting to be made. As stated, the back plate E is movable to adjust it to the thickness of the mold. The mold is provided with a vertical main entrance gate Uthe position of which has to correspond with the hole S in plate G. From thel main gate one or more smaller branches run to the different articles formed in the mold.

- The proper manner of cutting the gates required is well known to artisans in the line of cutting. The molds mustbe perfectly dry if good, sharp castings are wanted. The mold is placed vertically in the apparatus against the plate B; then plate E is pushed forward against the mold; then the side plates are closed and locked by the cross screw bars X and then the mold is firmly closed t0- gether by bringing the screws J to act against plate E. After this, the top plate G is brought down vand fastened by the sliding bolt R3. The next step is to bring theA metal receptacle in position. The description and drawings show that the receptacleis connected to plate G by means of the swivel bolt and its hingeat point L which permits the raising of the receptacle and the laying of it back. It can also ne turned sidewise on the swivel bolt. the receptacle have both these motions. By raising the receptacle the hole S is free so that the asbestos washerS2 may be placed fon the plate G in such away that the hole in washer corresponds to the hole S in plate G. Then the asbestos tube or ring S'is slipped into the hole S so that the liange on the ring will rest on the edge of the hole in the Washer. This done, the receptacle is brought down and fastened by bolt K2. The receptacle. is lined with a non-conductor of heat, to which the washer forms a non-heat conducting botf tom. The washer serves also asa fireproof packing at the joints of the receptacle with the plate G. The hole S lined as aforesaid forms the inlet ofthe fluid metal to the molds. This inlet isl closed by resting the stem O over it. It is held down air-tight by the weightW acting on the lever P. The corners O4 and C3 are next luted as described before which makes the apparatus ready for casting.

-Shortly before filling the metal receptacle with huid metal, the air is well exhausted out of the mold'by means of a good vacuum pump attachedfto the pipe P2 which enters the case'nearthe bottom of plate B. The air finds an easy passage through the pores of the mold tpftthe pipe P2. The working of the pump imsgkept up during the act of filling the receptacle, 'also until the metal has filled the mold and has become fully set.

Whenl the metal receptacle has received sufficient metal to fill the mold with a surplus for a head, then the valve stem O is 4lifted only about one inch .when the pressure of the atmosphere will quickly force the metal into the mold and till every cavity of it. The valve stein. O should never be raised too much or out of the metal until the mold is filled or else the air will rush into the mold with the metal and spoil the casting.

As soon as the surplus of metal left in the receptacle has become set, the receptacle must be quickly detached so that the gate may be easily broken before the metal cools su'i- It is desirable, as will be shownkthaty roo it. -After this themoldaud castings are re` moved from. thecase.

` lllaving sthus described our invention, the

followingis'whatiwe claimas newtherein and desiretofseeure by Letters Patent:

1. The fco'mbination ofthe base plate A, the upright `plate B tiz`cedthereto, the hinged side plate's"O,'tl1e Vadjustable ip'late E, the A"hinged top "-plateG,`the edges of plates B, C and E being `suitablyehanneled o'r Ygrooved toreeeive "packing,substantially as and `for the pu rposes set forth.

2. Thecombination of the base'plate A, the fixed `and adjustable plates B, E, theside plates Cyand thelanged 'air *tight packing plate E2 farranged'and adapted to operate substantially as set forth.

3. The combination of the 'base -yplate A, xed upright plate 4B, `hinged lside plates() having hooks C2, ladjustableupright plate E, screws J and cross bars X, arranged and adapted to operate, substantially as set forth.

4. The combinationlof the base plate A, uprig-ht plate B,side *plates C, adj nstable upright plate E Ahavingarm F provided with roller F2, substantially asand forthepurposes set forth. p I

`5. Thecombination o`f thebase plate A, upright plate B, suitable side `plates,adj ustable upright plate E and ltop plate G hinged to said plate E, *movable "therewith and carrying on itself the hingedand pivotedlever K3 with its receptacle K, "rod O, lever P,support T and weight W all adapted to be removed by lifting the leverfK, substantially as and for the 'purposes' setforth.

6. Thecombination `inra casting-apparatus with afsuitable mold casing,of a movable top plate,`a metal receptacle and its lever connected to said plate by ahin'ge and swivel, an upright arm T on said lever, valve stem O, cross lever P and Weight W, substantially as and forthepurposesset" forth.

7. In a casting apparatus,`thelconibination of the top plate G, "having an opening S the asbestos tube or ring S3, fitting said'opening inplate Gr, the asbestos Washer S2 and the metal receptacle hinged to `said top plate, substantially as set forth.

J. J. C. SMITH. EUG. C. SMITH.

Witnesses as to J. J. C. Smith:

M. V. BIDGooD, J. GREEN. Witnesses as to Eugene C. Smith:

HARRY F. COONEY, DAVID E. KINNON

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