US2830337A - Investment machine for making shell molds - Google Patents

Description

April 15, 1958 J. A. SHELBY ETAL 2,830,337

- INVESTMENT MACHINE FOR MAKING SHELL MOLDS Filed July 1, 1954 4 Sheets-Sheet 1 12 J 20 17 1 I/n tons:

' e/afin @4. Jkezz Mllan F Paton April 15, 1958 J. A. SHELBY L 2,830,337

INVESTMENT MACHINE FOR MAKING SHELL MOLDS Filed July 1, 1954 4 Sheets-Sheet 5 17 13 J5 wib'fi .14 1 1 i I i m lfl L I g; E 1 5 April 15, 1958 J. A. SHELBY E L 2,830,337

INVESTMENT MACHINE FOR MAKING SHELL MOLDS Filed July 1, 1954 ,4 Sheets-Sheet 4 LL I @fllan I'Pazou United States Patent generally heated and a sand and suitable binder mixture is delivered to the heated patternwhereupon a relatively thin frangible shell is formed. This shell is suitably cured by heating or bakingand during the casting operation a pair of complementary shells are placed together in assembly whereupon casting material is poured into the cavity provided by the shell-type molds. Various devices for investing the pattern with the binder sand mixture have .been devised. Most of these devices have performed satisfactorily but they have not been designed for high production of shell molds. It is a prime object of this invention therefore to provide an improved investment machine for manufacturing shell-type molds on a production basis. i

It is still a further object of this invention to provide an improved investment apparatus adapted to be placed adjacent a plurality of conveyors which deliver a pattern to the investment machine whereupon the pattern is covered with a sand binder mixture while it is in a heated condition and whereupon it is discharged to one of the conveyors for conveyance to a baking oven for suitably curing the shell mold.

Still another object is to provide an improvement in a shell mold investment apparatus the improvement including means for releasably locking a pattern carrier on the platform of an investment machine, the carrier being locked during investing of the pattern with a sand mixture "whereupon the locking means is releasable for releasing the pattern carrier so that it can be delivered to suitable conveying means adjacent the apparatus.

A still further object of the invention is to provide improved means for investing the heated pattern witha sand binder mixture including a device for rotating the pattern to an inverted position for discharging excess investment material from the pattern.

These and further objects will become more readily apparent from a reading of the specification in connection with the accompanying sheets of drawings.

In the drawings:

Figure 1 is a side view, in elevation, of an improved investment apparatus for manufacturing shell-type molds;

Figure 2 is a front view, in elevation, of the apparatus shown in Figure 1;

Figure 3 is an elevational view showing a portion of an investment machine taken substantially along the line 33 of Figure 1;

Figure 4 is a cross-sectional view taken substantially along the line 44 of Figure l;

Figure 5 is a cross-sectional view through the investment apparatus taken substantially along the lines 5-5 of Figure 2; and,

Figure 6 is a sectional view similar to Figure 5 showing one operating position in the operating cycle of the investment apparatus. A

An investment machine is generally designated by the reference character 10. The machine 10 comprises a supporting structure 11 consisting of upright members 12 ,gate 51 is connected to a pivot pin 52 pivotally connected 2,830,337 Patented Apr. 15, 1958 :track rollers 13. The track rollers 13, which are positioned on the front upright members 12, are suitably journ-alled on a shaft 14 which is carried in bearing members 15. The track rollers 13 which are carried on the rear upright members 12 are suitably journalled on stub shafts 17 in turn journalled in bearing supports 18. Each roller 13 of the rear upright members 12 is supported on two bearing supports 18 one of which is'suitably supported on an upright member 19 as best indicated in Figure 3. The front and rear uprights 12 are securely connected together by means of a horizontally extending beam 20. In addition the uprights 12 are suitably connected by means of.

supporting members 21 extending laterally relative to the beams 20.

The supporting structure 11 supports a rotatable frame 22. The rotatable frame 22 comprises a pair of laterally spaced and parallel circular track members 23. The track members 23 are connected at their forward portions by means of a lateral brace 24 and are suitably connected at rear portions by means of upper and lower channel beams 25.

A platform is provided on a rotatable frame 22, this platform including channel members 26 and 27 positioned in parallel relation as best shown in Figure 4. The channels 26 and 27 are suitably connected to beams 28, which as best shown in Figure 2, are connected to the track members 23 by means of angle members 29. A plurality of conveyor rollers 30 are suitably pivotally connected to the channels 26 and 27 to provide a roller conveyor.

The rotatable frame 22 also supports a plurality of longitudinally extending, or normally upright, track frame members 31. The upright track members 31 have each suitably connectedthereto parallel vertically extending upright rods 32 defining a suitable vertically extending track .means. A bracket structure generally designated at 33 is best shown in Figures 4, 5 and 6. The bracket structure 33 includes side plates 34 suitably connected by means of a an end plate 35 which is also connected to a bottom plate 36. A plurality of rollers 37 are suitably journalled on the side plates 34, the rollers 37 being positioned to roll 1 on the tracks formed by the upright rods 32. A pair of laterally spaced and parallel T-beams 3S suitably support an investment material drum or hopper generally designated by the reference character 39.

The drum or hopper 39 comprises a circular housing 40 having an inlet opening 41 and an outlet opening 42. An arcuate closure gate 43 is positioned within the drum 39 for suitably opening and closing the outlet 42. A pair of laterally spaced track members 44 are positioned immediately adjacent the outlet opening 42. The track members 44 serve to provide guides for the arcuate closure gate 43. A pair of arms 45 are connected to the :gate 43, these arms being rigidly connected to a shaft 46. As best shown in Figure 4 a shaft 46 is pivoted on the drum 39 and is connected to a crank arm 47 which in turn is connected to a piston arm 48. The piston arm 48 is reciprocably positioned within a cylinder or fluid extensible device 49 which is pivotally connected, as indicated at 50, in Figure 4, to one of the T-beams 38.

An inletclosure gate 51 is positioned over the inlet opening 41 as best shown in Figures 5 and 6. The closure to the drum 39, the said pin 52, in turn being connected 1 to an arm 53 adapted to rotate the closure gate 51 on the said pivot pin 52. The arm 53 is connected to a piston rod 54 reciprocably positioned within a fluid extensible device 55. The extensible device 55 is connected asindicated at 56 to the drum 39.

in Figure underneath the chute extension 61.

3 As best shown in Figures 1 and 5 a'supply chute 57 is positioned above the inlet opening 41. The supply chute 57 includes a valve member 58 adapted to suitably control the discharge ofmaterial from the chute 57 by means of a fluid extensible device 59. The chute or hood 60 is connected to the material drum 39, and an extension 61 in turn connected to the chute 60. The drum 39 is closed chamber within the extension 61 in the chute 60.

adapted to be vertically moved on the upright trackmembers 31 by means of a piston rod 62 which is connected to the channel bottom member or plate 36. The piston rod62 in turn is reciproc'ably positioned with respect tora fiuid extensible device 63suita'bly positioned on a rollers 30. A pattern support 67 is mounted on the carrier 65and in turn supports a pattern 68. As best shown in Figures 2, 5 and 6, the carrier 65 is provided with oppositelydisposed access openings 69. A stripper plate'70 is vertically movable within the carrier 65 and is maintained therein by means of substantially parallel' angle supports 71 suitably connected to the carrier 65.

Means for maintaining thecarrier 65 within theinvestment machine 10 is provided in the form of releasable holders generally designated at 72. The releasable holders 72 are suitably supported by means of brackets'73 on angle members 74 connected to beams 28 (bestshown One of the releasable holders 72 is positioned on opposite sides of the pattern carrier 65. Each holder172 includesa laterally extending shaft 75 which is mounted for rotation on the brackets 73. A crank arm 76 is attached to each shaft 75 the crank arm being mov- -able by a piston 77 on a fiuid extensible cylinder 78." As

best shown in Figures 2 and 5, ears 80 extend upwardly from the angle 74 these ears also supporting the shaft 75. A finger 81 is connected to each laterally extending shaft 75, the fingers extending through the openings 69 as, best shown in Figures 5 and 6. The fingers 81 are adapted to engage the upper edge of the stripper plate 70' and to maintain the same in lowered relation relative to the angle 71. This in efifect locks the carrier 65 in position for the investment operation.

A pair of pulleys 82are connected for rotation with a shaft 83 which is suitably journalled on bearingmem- -bers 84 suitably supported on the transversely spaced horizontal beams 20. A pair of cables 85 are wound aroundthe pulleys 82 and are connected to the circular goperation the carrier 65, which contains the pattern 68, is delivered to the conveyor rollers 30. At this stage of the operation, the apparatus is in the position'shown in Figures 1 and 2, the carrier has moved into position and the extensible devices 78 are effective to rotate the shaft 75 in such a manner that the fingers 81 engage the upper edge of thestripper plate 70 to securely maintain the pattern carrier and pattern 65 in position immediately As indicated" in Figure 1, the drum 39 is in a filling position with reference to. the supply chute 57. The inlet closure gate 51 is opened during the upward movement. of the drum '39 and the valve 58 is effective to permit the discharge of a resin binder mixture to the interior of the drum" 40.

Material is now delivered tofthe drum. until it reaches a-level position immediately below thc lowerm'ost: point of-the chute 57. The drum 39 is then lowered relative --to the chute 57 and the inlet closurev gate 51 closesto :suitably close the inlet opening of the drum. The drum isi no'w mo'ved downwardly until the extension 61- completely isurrounds'the pattern and provides in 'e'ffect a The gate 43, which has been closed until this time, is now opened by means of cylinder 49. Material from the drum now drops down upon the pattern 68. The pattern 68 has been heated and the material consisting primarily 'of a binder and sand mixture forms a thin layer on top of the heated pattern 68. After the pattern 68 has been invested with the material it is desired to immediately. remove. the excess from the pattern and return the same to the drum 39. At this point the rotating frame 22 is rotated by means of the cables (and a suitable power unit not shown which is connected to the shaft 83) thereby causing the units mounted thereon to rotate to the position shown in Figure 6. In this position the closure gate 43 of the drum is open and any excess sand and binder mixture which is placed on the pattern is returned by gravity to the drum. The gate 43 now closes and the rotatable frame 22 returns to its normal position shown in Figure 5 whereupon the drum 39 can again be moved upwardly in filling position with respect to the supply chute 57. The release holders 72 arenow released so that the carrier can be moved from the rollers 30 to one of the adjacent conveyors (not shown) which will deliver the carrier and pattern to a suitable curing oven.

T o summarize the operation it can be stated that the drum moves up'into position for receiving a binder sand mixture from the chute 57. Thereupon the drum is lowered until the extension 61 is disposed insubstantially sealed relation around the pattern 68. The gate 43 is now opened and material descends onto the pattern 68 whereupon the pattern frame and pattern are rotated so that any excess sand is returned. tothe drum. After return of the excess material to the drum the outlet gate is again closed and the drum is moved to its filling position. The releasable holders are released so that the carrier can depart from the conveyor rollers 30 to another conveyor for delivery to the curing oven.

The apparatus shown can easily produce, on a large quantity basis, shell molds as the patterns are-delivered from the preheating oven. The unit can be quickly rotated to a position where any excess binder sand mixture is returned to the hopper. By the novel arrangement shown, a pattern carrier may be utilized, the pattern carrier being suitable to support the pattern in position during variousoperations before and after it has been placed in the investment machine. By suitably connecting the device to a switch control unit, complete automatic operation can readily be procured. Thus it can be seen that the objects of the invention have been fully achieved and that a mass production shell mold investment apparatus has been provided. It must be understood that changes may be made in the invention without departing from the spirit of the invention or the scope thereof as defined in the appended claims.

What is claimed is:

1. An investment machine for investing a pattern with a mold. material comprising; a supporting structure, a

plurality of bearing rollers mounted on said supporting opening, a platform, carried by said frame, conveyor meanson said platform, a pattern carrier movable on said conveyor to a position beneath said hood, said carrier comprising a box frame having a stripper plate'enclosed 'thereinfor relative reciprocating movement relative to tensible means adapted to engage said stripper plate for locking said carrier in position on said conveyor, second fluid pressure extensible means connected to said frame and to'said bracket for moving said drum to a position whereby said chute extends through said inletopening 'for supplying material to said drum, said second extensible means being adapted to move said drum to a second position whereby said hood is in engagement with said carrier over a pattern carried therein and said drum is moved away from said chute, means connected to said inlet closure gate for closing the same in the second position of said drum, means connected to said outlet closure gate for opening said gate during the second position of said drum whereby material within said drum is deposited on the pattern, and means for rotating said frame with the drum in said second position whereby excess material l on the pattern is returned to said drum by gravity.

' 2. An investment machine for investing a pattern with a mold material, comprising; a supporting structure, a rotatable frame including a pairof laterally spaced and aligned circular track members, said track members being 'rotatably supported on said supporting structure, a pair of longitudinally extending track members mounted on said frame, a bracket movably mounted on said longitudinal track members, a drum supported on said bracket,

. said drum having an inlet opening and an outlet opening, I an inlet closure gate for said inlet opening, an outlet .closure gate for said outlet opening, a hood connected to said drum and in communication with said outlet opening, a supply chute positioned above said inlet opening, a platform carried by said frame, conveyor means on said platform, a pattern carrier movable on said conveyor vto a position beneath said hood, said carr er comprising a box frame having a stripper plate enclosed therein for relative reciprocating movement relative to a pattern .carried on said carrier, first fluid pressure extensible means adapted to engage said stripper plate for locking said carrier in position on said conveyor, second fluid pressure extensible means connected to said frame and to said bracket for moving said drum to a position where- -by said chute extends through said inlet opening for supplying material to said drum, said second extensible means being adapted to move said drum to a second position whereby said hood is in engagement with said carrier over a pattern carried therein and said drum is moved away from said chute, means connected to said inlet closure gate for closing the same in the second position of said drum, means connected to said outlet closure gate for opening said gate during the second position of said drum whereby material within said drum is deposited on the pattern, and means for rotating said frame with the drum in said second position whereby excess material on the pattern is returned to said drum by gravity.

3. An investment machine for investing a pattern with .a mold material, comprising; a supporting structure, a

rotatable frame including a pair of first track members, said first track members being supported for rotation on said support, a pair of second track members mounted ;on said frame, a' drum supported on said second track members, said drum having an inlet opening and an outlet opening, an inlet closure gate for said inlet opening, an outlet closure gate for said outlet opening, a hood connected to said drum and in communication with said outlet opening, a supply chute positioned above said inlet opening, a platform carried by said frame, a pattern carrier on said platform beneath said hood, said carrier being adapted tosupport a pattern, first fluid pressure extensible means adapted to engage said carrier for locking said carrier in position on said platform, second fluid pressure extensible means connected to said frame for moving said drum to a position whereby said chute extends through said inlet opening for supplying material to said drum, said second extensible means being adapted,

nected to said inlet closure gate for closing the same in the second position of said drum, means connected to said outlet closure gate for opening said gate during the second position of said drum and material within said drum is deposited on the pattern, and means for rotating said frame with the drum in said second position whereby excess material on the pattern is returned to said drum by gravity.

4'. An investment 'machine for investing a pattern with a mold material, comprising; a supporting structure, a rotatable frame including a pair of laterally spaced first track members, said first track members being rotatably supported on said supporting structure, a pair of second track members mounted on said frame, a bracket movably mounted on said second track members, a drum supported on said bracket, said drum having an inlet opening and an outlet opening, an inlet closure gate for 'said'inlet opening, an outlet closure gate for said outlet p to said bracket for moving said drum to a position whereby said chute extends through said inlet opening for supplying material to said drum, said second extensible means being adapted to move said drum to a second position whereby said hood is over a pattern carried on said carrier, means connected to said inlet closure gate for closing the same in the second position of said drum, means connected to said outlet closure gate for opening said gate during the second position of said drum whereby material within said drum is deposited on the pattern, and means for rotating said frame with the drum in said second position whereby excess material on the pattern is returned to said drum by gravity.

5. An investment machine for investing a pattern with a mold material, comprising; a supporting structure, a frame rotatably supported on said supporting structure, a pair of track members mounted on said frame, a drum supported on said track members, said drum having an inlet opening and an outlet opening, a hood connected to said drum and in communication with said outlet opening, a supply chute positioned above said inlet opening, a platform carried by said frame, a pattern carrier on said platform beneath said hood, said carrier being adapted tocarry a pattern below said hool, first fluid pressure extensible means adapted to engage said carrier for locking said carrier in position on said platform,'second fluid pressure extensible means connected to said frame for moving said drum to a position whereby said chute extends through said inlet opening for supplying material to said drum, said second extensible means being adapted to move said drum to a second position whereby said on the pattern is returned to said drum by gravity.

6. An investment machine for investing a pattern with a mold material, comprising; a supporting structure, a frame supported on said support, a drum supported on said frame, said drum having an inlet opening and an outlet opening, a hood connected to said drum and in 7 communication with said' outlet opening, a supply chute positioned above said inlet opening, a platform carried by said frame, conveyor means on said platform, a pattern carrier movable on said conveyor to a position beneath said hood, said carrier being adapted to support a pattern beneath said hood, means for locking said carrier in posipattern, and means for moving said frame with the drum in said second position whereby excess material on the pattern is returned to said drum by gravity.

7. An investment machine for investing a pattern with a mold material, comprising; a supporting structure, a frame rotatably supported on said support, a drum supported on said frame, said drum having an inlet opening and an outlet opening-a hood connected to said drum and in communicationwith said outlet opening, a supply chute positioned above said inlet opening, a platform carried by. said frame, a pattern carrier supported on said platform beneath said hood, said ,carrier being adapted to support apattern beneath said; hood,

first actuating means connected to saidframe' for moving said drum to a position whereby said chute extends through said inlet opening for supplying material to said drum, said first actuating means being adapted to move said drum to a second position whereby said hood is positioned over a pattern carried on said carrier, means connected to said inletopening for closing the same in the second position of said drum, means connected to said outlet opening for opening the same during the second position of saiddrum whereby material within said drum is deposited onthe pattern, and second actuating means for rotating said frame with the drum insaid second position whereby excess material onthe :pattern is returned to said drum'by gravity.

8. An apparatus for investing a pattern with a mold material comprising; a support, a frame including a pair of circular track members rotatably carried by saidsupport, a conveyor carried by said frame, a pattern .carrier supported on said conveyor, said carrier having a pattern supported thereon, a second frame supported on said first frame, a drum on said second frame, said drum having aninlet opening and an outlet opening, a supplychute positioned in proximityto. said inlet opening, a hood connected to said drum and adapted to communicate with said outlet opening, actuating means connected to said second frame for raising the same and said drum on the track members into a first position whereby said chute extends through said inlet opening into said drum, said actuating means being adapted to move said:drum to a second position remotefrom saidchute whereby said outlet opening and hood is disposed over said pattern and material is directed through said outlet opening over said pattern, inlet closure means adapted to-close said inlet opening during the second position, means to open said outlet opening during said second position, and means connected to said first frame for rotating the same relative to said support whereby excess material on said pattern returns by gravity to said drum through said outlet Opening.

9. An apparatus for investing a pattern with a mold material comprising; a support, a frame including apair of circular track members rotatably carried said support; a conveyor carried by said frame, a pattern carrier supported on said conveyor, said carrier having a pattern supported thereon, a second'frame supported onsaid first frame, a drumon said second frame said drum having an inlet opening and an outlet opening, asupply I chute positioned in proximity to said inlet opening,.actuatingmeans connected to said second'frame for moving the same andsaid drum on thetrack members into a first position whereby said chute extends through said inlet openinginto said drum, said actuating means being adapted to move said drum to a second position remote from said chute whereby said outlet opening is disposed over said pattern and material is directed through said outlet opening over said pattern, inlet closuremeans adapted to close said inlet opening during the second position,-means to open said outlet opening during said second position, and means connected to said first frame for rotating the same relative to said support whereby excess material on said pattern returns by gravity to a said drum through said outlet opening.

10. An apparatus for investing a pattern with a mold material comprising; a support, a frame including a pair of circular track members carried by said support, a platform carried by said frame for rotation about a horizontal axis, a pattern carrier supported on said platform, said carrier having a pattern supported thereon, a second frame supported on said first frame, a drum on said second frame, said drum having an inlet opening and an outlet opening, a supply chute positioned in proximity to'said inlet opening, actuating means connected to said second frame for moving the same and said drum" onthe track members into a first position whereby said chute extends through said inlet opening into said drum, said actuating means being adapted to move said drum to a second position remote from said chute whereby said outletopening is disposed over said pattern and material is directed through said outlet opening over said pattern, inlet closure -means adapted to close said inlet opening during the'secend position, means to open said outlet opening during said second position, and means connected to saidfirst frame for rotating the same relative to'said support whereby excess material on said pattern returns by gravity to said drum through said outlet opening.

11. An apparatus for investing a pattern with amold material comprising; a, support, a frame carried bysaid support for rotation about a horizontal axis, a conveyor carried by said frame, a pattern carrier supported on said conveyor, said carrier having a pattern supported thereon, a second fame supported on said first-frame, a drum on said second frame, said drum having an inlet openingand an outlet opening, a supply chute positioned in proximity to said inlet opening, a hood connected to saiddrum and adapted to communicate with said outlet opening,actuating means connected to said second frame for raising'the same and said drum into a first position whereby said chute extends through said inlet opening into saiddrum, said actuation meansbeing adapted to move said drum to a second position remote from said chute whereby said hood is disposed over said pattern and material is directed through said outlet opening over said pattern, inlet closure means adapted to close said inlet opening during the second positiom-means to open said outlet opening 3 References Cited in the file of this patent UNITED STATES PATENTS 2,317,574 Williams Apr. 27,-1943 2,659,944 Valyi Nov. 24, 1953 2,724,158 Davis et al Nov. 22,1955

OTHER REFERENCES Foundry,'November. 1952, page 265. Fortune, July 1952, pages 104-106, and 143.

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