US2012679A

US2012679A - Apparatus for forming castings

Info

Publication number: US2012679A
Application number: US706352A
Authority: US
Inventors: John M Craigo
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-01-12
Filing date: 1934-01-12
Publication date: 1935-08-27
Anticipated expiration: 1952-08-27

Description

Aug. 27, 1935. CRMGO 2,012,679

APPARATUS FOR FORMING CASTINGS Filed Jan. 12, 1954 Patented Aug. 27, 1935 UNITED STATES FATE [OFFICE f {APPARATUS Foe FORMING CASTINGS John M. Craigo, Hartford, Conn.

"Application a y 12, 1934, Serial No. 70 .352

' v 7 Claims. (01. 22-9) I nating from the molds ordies irregularities due to airbubbles and uneven distribution of the investment material.

In the accompanying drawing, .I have illustrated a suitable mechanical structure by means of which my improved method may be executed.

It is to be understood, however, that ,the;drawingis for the purpose of illustration only'a'nd is not to be considered as limiting the invention the scope of which is to be measured entirely by the'scope of the appended claims.

In the accompanying drawing,

Fig. 1 is an elevational view of a suitable. mechanical apparatus for carrying out the idea of the invention; I I a 'Fig. 2 is an elevational view on an enlarged scale of a portion of the apparatus. illustrated in Fig. 1; V

i Fig. 3 is a sectional view on theline' 3'3-.of Fig. 2;

Fig. 4 is a sectional viewon .the line 14-4" or Fig. 3; and I x Fig. 5 is a fragmentary'elevationaluview of a portion of my improved apparatus, particularly illustrating certain features of the method of operation thereof.

Referring to the drawing in detail, the numeral,

l generally indicates a machine used in form-' ing castings, such as are used for dental crowns and inlays. This machine comprises a flat base portion II from oneside of which a standard l2 extends vertically upwardly. Thisstandard I2 is provided at its upper end with a horizontal portion i3 overlying the upper surface of the base H and through this horizontalfportion adjacent to the extremity'thereof there is a' vertical bore l4 through which extends a vertically adjustable member or tool holder I 5. Vertical movement of the member IS in the bore l4 may be obtained by suitable means, such as the pinion I 6 jour .naled in the portion l3 of the standard l2 and provided with gear teeth l1. which cooperate with the teeth Ila. of a gear rack formed on the side of the member l adjacent to "the pinion. The

shaft of the pinion l6 maybe extended outside of the standard and may be provided int'thisextended portion witha lever I8 extendingtherethrough for rotating the pinion. The vertically adjustable member I 5 may be lockedin any position offvertical adjustment by a suitable means,

such as a set screw 20. The memberor tool holder I5 is provided at the lower end thereof with an axial wel1'22 forthe reception of ,tool stems, and suchtool stems may be locked in the tool holder by suitable means; such as a set screw 24 carriedby the tool holder in: the portion thereof through which the well 22, extends. A vertical bore or aperture 25 is providedinthe'base l l immediately b'elowthe tool holderl5 in axial alinement with the bore M; the purpose of the bore '25 being to'support ,variouspieces of operative mechanism, such as anvils, dies, turrets, and mold .casingsupon thebasea,

In carrying outmy improved method, I utilize. a pattern .holder 21 preferably formed-of. brass or other suitable heatresisting material- 3 This pattern holder, as illustrated in Fig. 2, comprises t a circular disk portion 28 upon one side of. which is formedradepending portion 29 having a somewhat conical or-spherical contour. holder is further provided with a concentric aper- .20 The molded ture ,30 extending therethrough. The patterns,

as indicated at 32, and 33, are formed of wax or moldine, or other suitable 'material, and are. at-' tached to metallic pins, as indioatedat 35. The ends of these pins oppositethe'ends to which the patterns areattached are inserted in the aper ture30, and the aperture is then .fille d .with a material such as a. suitable wax composition to hold the patterns in fixedpositionrelative to the pattern holder.

The investment ormoldmaterial iscontained in a suitable receptacle, suchas the mold ring 31, thebottom ,of which is closed bya'rubber dam 38. This receptacleis mounted in a turret,

I generallyindicated at .40, having an upper flanged disklike portion 4| v.up'onwhich isformed a con centric stem "42 adaptedto. fit in the aperture 25 for rotation: therein. This construction locates the receptacle 3'! immediately below the tool holder. l5Hin axial ,alinement therewith 'for con centric rotation relative thereto. Forum purpose of securing the pattern holder 21 to .the'tool holder l5, I-have provided a mechanism, general ly indicated at: 45, comprising averticalstande ard 41.ofzpreferably.oblongacross sectionlhaving at the upper end thereof a 48 of thinner. section. r

To the portion 48, I have secureda stem 50 by suitable means, such as riveting orwelding. This stem 50'fitsintothe well 22in theltool holder horizontal extension I5 and maybe locked thereinby, the set screw 24. a

When the members are suitably assembled the verticalportion of the standard is, offset from the common axis of the tool holder and the aperture 25 on the side of the axisi'adjacent to'the standard 12; J The lower endoflthe vertical'portion 4'! of the support 45is provided with a hori.-.

zontal aperture 53 extending therethrouglnand ill in this aperture is journaled the stem of a bracket member, generally indicated at 55 in Fig. 3. This bracket member 55 comprises a cylindrical journal portion 56 terminated at one end by an abutment flange 58.. The journal portion 55 may be secured in the aperture5'3 by suitable'means, such as the bearing screw 60. A stem portion 62 extends from the flange 58 on the side thereof ope, 1 positethe journal portion 56 and terminates in a flat disklikemember 65 the sides of which are cut away along chords perpendicular to thekaxis of the journal and stem to proyidea retaining member in the form of a zon'e 'o'f a circle; "This retaining member is provided along the opposite circumferential sides thereof with depending flanges, as indicated ato l lnEF-ig-sl '4 and order to secure the pattern holder 21 to the pore tion 6 5 of the bracket 55, I-have provided a pair of. '

clips

68 and 69 inthe form-of flat strap'or bar members :having their outer extremit iesbent under, as indicated at T2 to iorm dogsor abutments to underlie the disk portion: 2801 the pattern holder-21 and-latch the same to the bracket. The extrenn-ties of the members {58an'd 68 are bent upwardly, as indi'cated at fi; to dorm finger pieces for moving the members. Y overlappingportion of thesemembers are out away, as

. 19 is inserted between the fingerpi-eces -15 to nor 3o indicated at Ii-in 3,- and'acornpressionspring mally urgethe finger pi eces apart/and at the same time urge the dogs 12 into position to en'gage the disk portion 28 of the member 21. These mem =bers t8 and '69 are secured to the portion-65' 0f the member 55 by meansof rivets or screws, as indicated at 89, extending through-elongatedslots 82 having their headspositionedabove and bearing on the upper suriac'es of the members. "in -combination with the slidable members 68 and $9,

I have provided a centering device in the zform of i a block 84 secured to the disk 65 by screws;-as indisengage both of the dogs .12 beneath the flangedsportion 28 of the lpattemihotder 21;

journal portion of 0f the member 55115 provided within the aperture '53 with a plurality foi -radial depressions 36 particularly illustratedv m Fig. 4. These depressions. are 'spacedl' at 'somewl'iat, tin- ,eoual angles around the circumference- M the journal" member. 'and' are. adapted to be engaged bya detent 92 pivoted in the 'vertical'portion l 'l of the bracket means of a transverse pin93. The-detent 'SZ- hasa handle port-ionSl extending outof the vertical member 41 and at dog oft-latch portion .95 adapted to engage :in the recessesnu, one side "of the 'dog 95 being roundedmofi" softhat the member 55 may be rotated-about its; axis in one direction, but will be releasably restrained fromrotation in-the opposite direction by the engagement-of thedetent in-one of thejrecesses. :A depression Sit-is pr'ovidedlin the vertical member 41 for the. accommodationof the detent filaand this recess is preferably covered-.jby a plate 8-! secured tothe member 41 by suitable means,:such

as screws "98 .1 Above the detent the vertical member-is provided with 'a bore in which is inserted one, end-50f :a compression spring 99 the lower 1 end of, which bears againstthetop of the detent 92 to cause the detentto automatically engage in the recesses 90. It will be observed that the detent may be disengaged from any one of the recesses by a downward pressure upon the handle portion 94 thereof. 1 v iQReferring now to Fig.2, it will be observed that the disk portion 28 of the pattern holder 21 is 'lmurled, as indicated at I00.

The improved method of operation of this device is substantially as follows: After the wax patterns fland 33 are secured to the pattern holder 21 by means of the pin 35, the finger pieces 75 are pressed together and the flange 28 of the pattern holder is inserted between theflanges 6'! of the bracket 55. The finger pieces are then released, whereupon the pattern holder is rotatably secured in the bracket; The receptacle 3! is filled with investment material and-mounted upon *the turret 40 beneath' the pattern holder; 'i-t being und'ers'tood that my improved bracket has already been-properly mounted in the machined?! and that thetool holder i5 is in its uppermost position, as illustrated in Fig. '1. i The tool holder is'then lowered-by rotation of the pinion "1-6 to immerse the patterns 32 and 3-3 in the investment material contained in the receptacle'fi. After the patterns are completely immersed, the pinion I5 is rotated :in theopposite direction to raise the tool holder l5 to its uppermost position; The pattern holder 2 is' then rotated or oscillated inithe bracket 55, and the bracket is turned tovarious angular positions about a 'verticai-circumference, as indicated in Fig. 5, duringT-tnis rotation. The e'fl'ect' of this rotation is to cause the investment material to spread evenlybverthe i wax surfaces of the patterns end-if one df th'e patterns happens to bea crown in the form of a hollow cup, as illustrated at 33, r,otation of -the pattern holder in an inverted position 'willcause the:investment material to flow down into the interior of this cup and-fill the-same. The

knurled edge provided on the disk portion 28provides :a means for rotating the pattern holder and also a means for vibrating the same during rotatron by reason of the engagement of the-knurled edge with the ends of the flanges 61. This vibrationhas the efiect of a shaker actiona-nd tends to eliminate air bubbles from the investmentmateriaL coastedupon the pattern and to distribute the investment material evenly over 'theyentire surface of each pattern. Mter the investment material has been suitably distributed by this :.rotation and vibration at different angles aroundtha axis 'of the bracket member '55, the bracketniem'ber is rotated to bring the pattern holder into upright position, as illustrated in Figs. El. and 2, the tool holder 15 is thenlowered-b'y rotation :of the pinion 1'5 until the patterns 32 ended-are again imm'ersed in the investment material contained in the receptacle 3'1. sired,;1at'this point, the pattern holder may be released from the bracket by releasing the detents 12 therefrom "in the manner described above, and the-casting ring31, together with the plate *holder 2l ,.mayrbe removed 'from the maohine I II and setaside for the investment material to harden andithe machine used for another mold. After the-investment material .has'prope erly set and hardened, heat is applied thereto to melt the wax patterns and 33, and releasethe same from the pattern holder 21 The pattern holdenis then removed from the mold; and the I melted waxpoured out 6f the mold. tnfteriathis operation, melted metal: may be poured into the mold to ior'm the castings :flor which the patterns It 'de- 32 and 33 are made. The conical or spherical shape of the portion 29 of the pattern holder provides in the top of the mold a funnel to direct the molten metal into the channels provided'by the pins 35 leading to the molds provided by the patterns 32 and 33.

It will be observed that by this improved method and apparatus I have provided a means whereby a plurality of castings may be rapidly made with the same machine, and also one wherein the castings will be smoothly and accurately formed, since there will be no air bubbles in the mold and no lateral movement of the patterns upon their immersion in the investment material.

While I have illustrated and described a particular mechanical embodiment of the idea of the invention, it is to'be understood that the invention is not to be limited thereby, but the scope thereof is to be measured entirely by the scope of the appended claims.

Having now described my invention so that others skilled in the art may clearly understand v the same, whatI desire tosecure by Letters Patent is as follows:

1. A device for preparing a mold for making castings from patternscomprising, a receptacle for investment material, a pattern holder, means for-supporting the receptacle and pattern holder in vertical alinement, means for immersing said patterns in said investment material and withdrawing them therefrom, and means for securing said pattern holder to said supporting means for rotation or oscillation of said holder about axes disposed at right angles to each other when said patterns are withdrawn from said investment material, to cause said investment material to spread evenly over the surfaces of said patterns.

2. A device for preparing a mold for making castings from patterns comprising a receptacle for investment material, a pattern holder, means for supporting the receptacle and pattern holder in vertical alinement, means for immersing said patterns in said investment material and withdrawing them therefrom, means for securing said pattern holder to said supporting means for rotation of said holder about axes disposed at right angles to each other when said patterns are withdrawn from said investment material and means 'for vibrating said patterns when said holder. is

rotated about one of said axes to cause said investment material to spread evenly over the surfaces of said patterns.

3. A device for preparing a mold for making castings from patterns comprising a receptacle for investment material, a pattern hold-er, means for supporting'the receptacle and pattern holder in vertical alinement comprising, a base, a standard, and a vertically movable bracket rotatably secured to said standard, means for detachably securing said pattern holder to said bracket for rotation relative thereto about axes located at right angles to the axis of rotation of said bracket, means for raising and lowering said bracket to immerse said patterns in said investment material and withdrawthem therefrom whereby said pattern holder may be rotated when saidpat terns are withdrawn from said investment material to cause the investment material adhering to said patterns to spread evenly over the surfaces thereof, and means for locking said bracket at various angular positions about its axis of rotation.

4. A device for preparing a mold for making castings from patterns comprising a receptacle for investment material, a pattern holder, means comprising a base, a standard, and a bracket rotatable about a horizontal axis for supporting said 1 receptacle and pattern holder in vertical alinement, means for detachably securing said pattern holder to said bracket for rotation relative thereto, means for moving said bracket to immerse said patterns in said investment material and withdraw them therefrom, whereby said patterns may be rotated when withdrawn from said investment material to cause said investment material to spread evenly over the surfaces of said patterns, and means for positioning said bracket at various angles around said horizontal axis whereby said pattern holder may be rotated in. various planes parallel to said horizontal axis 5. A device for preparing a mold for making castings from patterns comprising a receptacle for investment material, a pattern holder, means comprising a base, a standard, and a bracket for supporting said'receptacle and pattern support in vertical alinement, means for detachably seduring said pattern holder to said bracket for rotation relative thereto, means for moving said bracket to immerse said patterns in said investment material and withdraw them therefrom whereby said patterns may be rotated when with- ,drawn from said investment material to cause said investment'material to spread evenly over the surfaces of said patterns, and a knurled rim on said pattern holder to cause vibration of said said ho-lderrelative to from, latch means for detachably securing .said

pattern holder to saidbracket for rotationrela tive thereto about an axis at right'angles to said horizontal axis, means for positioning said bracket at various angular positionsabout said horizontal axis, and aknurled rim on said pattern holder whereby the same may be manually rotated while held at various angular positions by said bracket. 7. A device for preparing a mold for making a base and a standard, a tool holder mounted in said standard for vertical movement towards and away from said base, means for moving said tool holder, a receptacle for investment material located onsaid base below said tool holder, a bracket carried by the lower endof said tool holder and supported for rotary movement about a horizontal axis, said bracket having a .plate portion provided with curved depending flanges at its opposite sides, a pattern holder having a knurled rim positioned slidably mounted on said plate portion and having their outer extremities bent under said flanges to form abutments adapted to underlie said rim -of the pattern holder and latch the same to the bracket, a spring between said clips and normally urging the same into holding position, and means for securing said bracket in various positions of angular adjustment with respect to said tool holder.

JOHN M. CRAIGO.

1 castings from patterns comprising a frame having between and engaging said flanges, a pair of clips