US3221377A

US3221377A - Mold forming method and apparatus

Info

Publication number: US3221377A
Application number: US285642A
Authority: US
Inventors: Loyal L Johnston
Original assignee: Herman Pneumatic Machine Co
Current assignee: Herman Pneumatic Machine Co
Priority date: 1963-06-05
Filing date: 1963-06-05
Publication date: 1965-12-07
Anticipated expiration: 1982-12-07
Also published as: GB1003133A

Description

Dec. 7, 1965 L. L. .JOHNSTON 3,221,377

MOLD FORMING METHOD AND APPARATUS Filed June 5, 1963 2 Sheets-Sheet 1 Fig.|. 48

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Dec. 7, 1965 L. l.. JOHNSTON 3,221,377

v MOLD FORMING METHOD AND APPARATUS Filed June 5, 1963 2 Sheets-Sheet 2 FigQz.

INVENTOR Loyal L. Johnston United States Patent O 3,221,377 MLD FRMING METHOD AND APPARATUS Loyal I... Johnston, Zelienople, Pa., assigner to Herman Pneumatic Machine Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed .lune 5, 1963, Ser. No. 285,642 14 Claims. (Cl. 22-17) The present invention relates to a mold forming method and apparatus and particularly a method and apparatus for forming foundry molds out of nely divided mold forming material such as foundry sand. The present invention is related to and also embodies improvements over a number of my copending applications including applications Serial Nos. 118,001, now Patent 3,165,794, issued January 19, 1965, and 118,002, tiled June 19, 1961, now abandoned and Serial No. 199,079, iiled May 31, 1962, now Patent 3,169,284.

One of the features of the present invention is a method of forming a foundry mold by moving a former through nely divided mold forming material in a ilask and additionally compacting the mold forming material at the end of the flask where the former enters as the for-mer enters the flask to suiciently consolidate the mold forming material which is being formed into a foundry mold that the mold forming material itself acts to guide the former as it advances through the flask. This enables great simplification of the apparatus and reduction in its cost. Such method has particular utility when the former is pulled through the flask as then a relatively short former can be employed which does not have at its trailing end a long guiding element to maintain the former in a straight path as it moves through the ask. A relatively short guiding element may be utilized on the yformer to insure that at the very beginning of its movement through the flask the former is confined to its proper path, or a trailing guiding element on the former may be eliminated entirely.

I have also incorporated in the apparatus certain improvements which facilitate the mold forming operation and contribute to production of a superior mold and also to economy of operation. I provide closure means at the end of the flask towardwhich the former moves as it advances through the flask `for preventing mold for-ming material from being ejected at that end of the ilask together with means (apart from the former) for moving the closure mean-s to inoperative position to permit the former to pass out of the flask and subsequently at the proper time in the cycle returning thel closure means to operative position. I also provide tension means acting between the portions of the apparatus at the respective ends of the flask to resist the tendency of such portions of the apparatus to move apart during useA of the apparatus which enables supporting means for portions of the apparatus to be economically designed to carry only static load.

Finally I provide mold forming apparatus comprising a ask, a base upon which the ask is adapted to stand in generally upright position, a cylinder, means independent of the base supporting the cylinder in position spaced above the base, a generally vertically operable piston in the cylinder, the piston carrying holding means adapted upon downward movement of the piston in the cylinder to engage the upper end of the flask to hold the flask down against the base, a former, means for moving the former upwardly through the flask when the flask is standing on the base to form a mold for casting in mold forming material in the ask and generally upright tension means connected at the bottom thereof to the base and at the top thereof to the cylinder resisting the upward reaction thrust of the cylinder when the piston is 3,221,377 Patented Dec. 7, 1965 acted upon by uid under pressure in the cylinder to press the holding means downwardly against the base so that the supporting means supporting the cylinder may be designed to carry only the static load of the cylinder and the mechanism carried thereby.

Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof and a present preferred method of practicing the same proceeds.

In the accompanying drawings I have shown a present preferred embodiment of the invention and have illustrated a present preferred method of practicing the same, in which FIGURE 1 is an axial cross-sectional view through mold forming apparatus constructed in accordance with my invention with portions cut away for clarity and to reduce the overall height of the gure;

FIGURE 2 is a transverse cross-sectional View taken on the line II-II of FIGURE 1;

FIGURE 3 is a transverse cross-sectional view taken on the line III-III of FIGURE l; and

FIGURE 4 is a transverse cross-sectional view taken on the line IV-IV of FIGURE l.

Referring now more particularly to the drawings, I provide a suitable foundation a portion of which is shown in chain lines in FIGURE 1 and designated generally by reference numeral 2. Fixedly mounted upon the foundation is a cylinder 3 having its axis vertical and closed at the top by a cylinder head 4 fastened to the cylinder by screws 5. At its bottom the cylinder 3 has a central aperture 6 in which is mounted a flanged sleeve 7 fastened to the cylinder by screws 8. Sealing rings 9 are mounted in the inner face of the sleeve 7. The cylinder head 4 has a aperture 10, and sealing rings 11 are mounted in the inner face of the cylinder head 4.

A piston 12 is disposed in the cylinder 3 and sealed to the cylinder wall by sealing rings 13. The piston 12 has a hollow downward projection 14 at its bottom which passes through the sleeve 7 and is sealed thereto by the sealing rings 9. Adjustable nuts 15 and 16 are threaded onto the projection 14 and upon movement of the piston 12 in the cylinder 3 are adapted to engage a bumper 17 to limit the extent of movement of the piston 12 in the cylinder 3. The piston 12 has an upward projection 18 which passes through the aperture 10 in the piston head 4 and is sealed thereto by the sealing rings 11. Fluid under pressure is admitted into the cylinder 3 below the piston 12 to raise the piston when desired. When the uid is exhausted from below the piston 12 in the cylinder 3 the piston and the mechanism carried thereby move downwardly by gravity. If found necessary or desirable downward movement of the piston 12 may be effected or assisted by fluid under pressure admitted to the cylinder 3 above the piston 12. Upward movement is limited by engagement of the nut 16 with the bumper 17 and downward movement is limited by engagement of the nut 15 with the bumper 17. As the parts are shown in the drawing the piston 12 is in its lowermost position permitted by the nut 15 in the adjusted position shown.

The cylinder 3 has circumferentially spaced upward extensions 19 carrying a ring 20 which is fastened to the extensions 19 by screws 21. At its upper face adjacent its inner periphery the ring 20 carries a flask seat or base 22. The ring 20 also carries ilask centering means 23 fastened thereto by screws 24 which may be a cornplete annulus or circumferentially spaced centering members.

Threaded to the upward projection 18 of the piston 12 at 25 is a hub pattern 26 which is of annular shape with an outer upwardly and inwardly inclined face 27 of proper shape to form a hub and an axial frusto-conical bore 28 with its larger end at the top and its smaller end at the bottom. The hub pattern 26 has an upwardly facing shoulder 26a upon which is disposed a sealing ring 26b which seals the hub pattern 26 to the ask seat or base 22 in the position of the parts shown in FIGURE 1 and which as the hub pattern moves upwardly into the flask presently to be described seals the hub pattern to the flask. Also the sealing ring 26h and the face 27 of the hub pattern 26 constitute mold forming material com- -pacting means having an important function presently to be described.

A former designated generally by reference numeral 29 is shown in FIGURE 1 as seated upon the hub pattern 26 with a frusto-conical downward projection 30 tting into the upper end of the bore 28. The former 29 has a shoulder 31 which seats atop the hub pattern 26. The hub pattern and the lower portion of the former are shaped to closely intert as shown so that the former is accurately positioned by the hub pattern when seated thereon.

The former is shown as being of thetype disclosed in my said application Serial No. 199,079 having Zones a, b and c Whose outer surfaces are respectively inclined to theaxis of the former at progressively smaller angles and a cylindrical zone d adjacent the shoulder 31. The functions of the various zones of the former are fully explained in application Serial No. 199,079 and therefore will not be repeated here.

The former 29 has therethrough an axial bore 32. A rod 33 extends through the bore and upwardly from the former 29, the bottom end 34 of the rod 33 being threaded and being screwed into an internally threaded socket 35 in a guiding member 36 which by the rod is held against the bottom of the former 29 with an interposed gasket 36a. The guiding member 36 has a downwardly projecting guide pin 37 guidingly received within a bore 38 in the piston 12. The bottom of the pin 37 is chamfered at 39 to ease the entry of the pin into and through the hub pattern 26 and into the bore 38 when the former 29 is lowered relatively to the hub pattern. Also, as the former is moved upwardly relatively to the hub pattern it is initially guided for a short distance by the guided relationship of the pin 37 in the bore 38. While 1 prefer to utilize the guide pin 37 in the bore 38 as just explained that guide pin is not essential and can be dispensed with in view of the compacting of the mold forming material which itself forms a guide for the former as mentioned above and as will be more specically described below.

Seated on the ask seat or base 22 is a flask 40 which is somewhat outwardly flared adjacent its lower end as shown in FIGURE l but which otherwise is of generally cylindrical shape. The flask 40 has a centering and seating portion 41 at its bottom which seats on the flask seat or base 22 and is centered by the centering means 23 as shown. The portion 41 of the flask is chamfered at 42 to facilitate its entry into the centering means 23. Permanently connected with the flask at its upper end so as in effect to form an integral part of the flask is a ring 43.

Referring now to the upper portion of the apparatus viewing FIGURE 1, there are provided any suitable supporting means shown in chain lines and designated generally by reference numeral 44 which support a cylinder 45 shown as having a ange 46 seated atop the supporting means 44. The supporting means 44 may be designed to carry only the static load of the cylinder 45 and the mechanism carried thereby as that cylinder is connected with the cylinder 3 by tension rods 47 which hold down the cylinder 45 when the reaction force exerted by the piston therein presently to be described tends to cause it to rise. Any suitable number of the tension rods 47 disposed about the axis of the apparatus are provided.

A piston 48 operates in the cylinder 45 and is sealed to the cylinder wall by sealing rings 49 A top cylinder head 50 is fastened to the cylinder 45 by screws 51 and a bottom cylinder head 52 is fastened to the cylinder 45 by screws 53. The piston 48 has reduced upwardly and downwardly extending

portions

48a and 48b respectively which are sealed to the cylinder heads 50 and 52 by sealing

rings

54 and 55. The piston 48 is double-acting means being provided for introducing fluid under pressure both above and below the piston to positively move it either downwardly or upwardly.

Threaded to the bottom of the piston 48 is a mounting member 56 having an upper annulus 57, a lower annulus 58 and circumferentially spaced vertical posts or columns 59. A spigot former 60 is threaded into the annulus 58 as shown and centering means 61 which may be either an annulus or a plurality of circumferentially spaced centering members are bolted to the annulus 58 by bolts 62. The spigot former 60 seats at 63 atop the ring 43 forming the upper extremity of the flask 4i), the spigot former being centered to the flask both by its engagement inside the ring 43 and by the engagement of the centering means 61 outside the ring 43. When fluid under pressure is admitted to the cylinder 45 above the piston 48 the spigot former is pressed down against the top of the flask and the flask is thus held down rmly against the flask seat or base 22 and centered by the centering means 23 and 61.

The upper faces of the lower annulus 5S of the mounting member 56 and the spigot former 66 are coplanar, and a spider 66 having radial spoke-like elements 69 which extend inwardly between the posts 59 may seat thereon. The spider 66 carries a sealing ring 67 having a cylindrical bore as shown and a conically tapered outer face 68 at its lower portion adapted to seat snugly within the spigot former 60 as shown. The sealing ring 67 is carried by the elements 69 through shear pins 76 so that the sealing ring 67 in normal operationis connected with the spider 66 and is in effect integral therewith. The reason for employing shear pins will be presently explained.

The outer extremities of two opposed radial spoke-like elements 69 of the spider 66 are offset upwardly as shown in FIGURE 1 and an extension 64 is fastened to each thereof by screws 65 so that the under surface of each of the extensions 64 is coplanar with the under surfaces of the radial spoke-like elements 69 whereby the inner edges of the extensions 64 seat on the annulus 58.

Connected with the upper annulus 57 of the mounting member 56 by screws 71 are opposed extensions or arms 72 having bores 73 containing bushings 74 through which the tension rods 47 pass as shown. Each extension 72 carries a cylinder 75 arranged with its axis vertical and seated atop the extension and fastened thereto in any suitable manner. Pistons 76 operate in the respective cylinders 75 and extend downwardly through the bottom cylinder heads 77 and through bores 78 in the extensions 72 and are connected at their lower ends at 79 as shown with the extensions 64. The pistons 76 are double-acting and fluid under pressure may be admitted either above or below the pistons; Control means are provided for admitting and releasing fluid under pressure to and from all of the cylinders 7S simultaneously so that the pistons 76 operate in synchronism. When the pistons 76 are forced downwardly the extensions 64 with the spider 66 connected therewith are pressed downwardly to rmly seat the sealing ring 67 in the spigot former 60. When the pistons 76 are moved upwardly in the cylinders 75 the extensions 64, the spider 66 and the sealing ring 67 are raised so that the sealing ring moves completely out of the spigot former 60 and to a position spaced a substantial distance upwardly therefrom. Guide rods 80 pass through the extensions 72 and are threaded into the annulus 58 and pass through hushed guides 81 forming part of the extensions 64.

Disposed within the mounting member 56 is an inner mounting member 82 having circumferentially spaced vertical posts or columns 83 which pass between the spokeflike elements 69 of the spider 66 and carry at their upper portions a ring 84 supporting against an inclined shoulder 92 near the bottom of the piston 48 an annulus 85 within which is a guide bushing 86. The guide bushing 86 has a friction fit in the annulus 85. The inside diameter of the annulus 85 is greater than the maximum outside diameter of the former 29 for a purpose to be presently explained. A sand displacing tube 87 is disposed about the rod 33 and at its lower end receives the nose of the former 29 and at its upper end is closed by a plate 88 and is held in position by a nut 89 threaded onto the rod 33 so that the tube 87 is maintained in position between the nose of the former 29 and the nut 89. At its upper extremity the rod 33 is connected at 9i) with a flexible tension member 91 which may be a rope, cable or wire which extends to a winch which is not shown in the present drawings but is shown in the drawings of applications Serial Nos. 118,001 and 118,002.

At the beginning of a cycle the piston 12 is in its lowermost position as shown in FIGURE l with the nut 15 seated on the bumper 17. The adjustment of the nut 15 determines the position of the hub pattern 26 at the beginning of the cycle. Such position determines the quantity of uncompacted finely divided mold forming material which the fiask will contain at the beginning of the cycle which quantity of uncompacted finely divided mold forming material in the flask in turn determines the hardness to which the mold forming material in the lower portion of the iiask is compacted while insuring formation of a mold for the casting of a pipe of desired length.

At the beginning of the cycle the piston 48 is in its uppermost position as are also the pistons 76. This means that the spigot former 60 is withdrawn upwardly a substantial distance above the position in which it is shown in FIGURE l and the sealing ring 67 is drawn up toward the upper portion of the mounting member 56. The former 29 is drawn up to a position with its zone d within the spigot former 60 and at an elevation such that the bottom of the pin 37 is above the elevation at which the top of the iiask 40 is shown in the drawing.

With the parts thus positioned the empty flask 40 is set atop the iiask seat or base 22 and centered by the centering means 23. Thereupon the former 29 is lowered until it seats on the hub pattern 26 as shown. The flask is then filled with finely divided mold forming material such as foundry sand which occupies the annular space within the ask and about the former seated on the hub pattern and about the tube 87. Thereupon the piston 48 is moved down to the position shown with the spigot former 60 in the upper end of the flask. The pistons 76 are moved down to the position shown in FIGURE 1 disposing the sealing ring 67 in the spigot former 60 as shown. The sealing ring 67 has a close but sliding fit about the tube 87.

Fuid under pressure is next admitted into the cylinder 3 under the piston 12 and raises the piston, forcing upwardly the hub pattern 26 which in turn pushes upwardly ahead of it the former 29. Since a portion of the space in the flask 40 which originally contained only sand is now occupied by the former and hub pattern the sand sealing ring 2611 and the face 27 of the hub pattern 26 in the lower portion of the flask 40 is compressed. The mold forming material compacting means comprising the compact the sand in the lower portion of the iiask against the outwardly iared inner wall at the lower portion of the ask and about the former. By the time the nut 16 engages the bumper 17 the sand is tightly compacted about the former and as the former advances it is guided by the cylindrical portion d thereof advancing in the guideway comprising the compacted sand. Also the former is initially guided by the guide pin 37 in the bore 38 until the guide pin rises out of the bore Whereafter the former is guided by the compacted sand in the flask which is progressively compacted to form a mold as the former moves upwardly.

As the former moves upwardly in the flask the tube 87 passes upwardly through the sealing ring 67 and the guide bushing 86. As the portion of the zone a of the former 29 exposed below the tube 87 approaches the spigot former 60 the unit comprising the sealing ring 67, the spider 66 and the extensions 64 is moved upwardly to a position toward the upper portion of the mounted lmember 56. This allows the former 29 to pass up through the spigot former 60. When the cylindrical portion d of the former 29 passes up into the spigot former 60 the piston 48 is raised in the cylinder 45 until the bottom of the pin 37 is at the elevation described at the beginning of the cycle. The piston 12 is moved down to its original position as shown at any time during the movement upward of the former 29. The flask with the mold formed therein is removed and replaced by an empty tiask and the cycle is repeated.

If through improper functioning the portion of the zone a of the former 29 which is outside the tube 87 strikes the sealing ring 67 while the sealing ring is in the position shown in FIGURE l the shear pins 70 will be sheared off and the sealing ring 67 will be pushed upwardly by the former 29. If such upward movement continues until the sealing ring 67 engages the guide bushing 86 the guide bushing will be unseated from the annulus 85, thus avoiding damage to the apparatus. All that need be done to place the apparatus in condition for further operation is to replace the broken shear pins 70 by new shear pins.

While I have shown and described a present preferred embodiment of the invention and a present preferred method of practicing the same the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

I claim:

1. A method of forming a foundry mold comprising advancing compacting means into one end of a tiask contaning mold forming material to compact the mold forming material at said end of the iiask, by the advancing compacting means pushing a tapered former through the mold forming material at said end of the iiask t0 simultaneously start the former through the flask and provide guidance for the former at said end of the flask by the mold forming material compacted by the advancing compacting means and further compacting mold forming material in the ask by the former as it is pushed by the compacting means, pulling the former the rest of the way through the tiask and while the former is thus being pulled through the flask further compacting by the former the mold forming material in the tiask and guiding the former by the compacted mold forming material.

2. A method of forming a foundry mold comprising advancing compacting means upwardly into the lower end of a generally upright tiask containing mold forming material to compact the mold forming material at the lower end of the tiask, by the upwardly advancing compacting means pushing a tapered former upwardly through the mold forming material at the lower end of the ash to simultaneously start the former through the ask and provide guidance for the former at the lower end of the flask by the mold forming material compacted by the upwardly advancing compacting means and further compacting mold forming material in the ask by the former as it is pushed upwardly by the compacting means, pulling the former the rest of the way upwardly through the flask and while the former is thus being pulled upwardly through the flask further compacting by the former the mold forming material in the ask and guiding the former by the compacted mold forming material.

3. A method of forming a foundry mold comprising advancing through a iiask containing mold forming material a former having means of smaller transverse cross section than the former extending forwardly therefrom through the end of the flask toward which the former advances, maintaining said end of the flask closed about said means` and sealed thereto continuously about the entire periphery thereof to prevent passage of mold forming material out of said end of the flask. until the former approaches said end of the flask, said end of the flask which is closed about said means having an opening of smaller size than the former, and while the former advances and shortly before the former reaches said end of the flask opening said end of the flask sufficiently to enable the former to move through said end of the flask.

4. A method of forming a foundry mold comprising pulling a former through a flask containing mold forming material by a tension element extending forwardly 'from the former through the end of the flask toward which the former is pulled with means of smaller transverse cross section than the former disposed about the tension element, maintaining said end of the flask closed about said means and sealed thereto continuously about the entire periphery thereof to prevent passage of mold forming material out of said end of the flask until the former approaches said end of the flask, said end of the flask which is closed about said means having an opening of smaller size than the former, and while the former advances and shortly before the former reaches said end of the flask opening said end of the flask sufficiently to enable the former to move through said end of the flask.

5. Mold forming apparatus comprising a flask, a former, means for advancing the former through the flask to form a mold for casting in mold forming material in the flask, closure means at the end of the flask at which the former passes out of the flask sealing said end of the flask for holding mold forming material in the flask as the former advances, the closure means when sealing said end of the flask being disposed in the path of the former, and means operable independently of the former for moving the closure means to inoperative position to permit the former to pass out of the flask.

6. Mold forming apparatus comprising a flask, a former, means for pulling the former through the flask to form a mold for casting in mold forming material in the flask, the pulling means passing out of the flask at the end of the flask toward which the former is pulled, closure means disposed about the pulling means at said end of the flask sealing said end of the flask for holding mold forming material in the flask as the former advances through the flask, the closure means when so disposed about the pulling means having an opening of smaller size than the former, and means operable independently of the former for moving the closure means to inoperative position to permit the former to pass out of the flask.

7. Mold forming apparatus comprising a flask, a base against which one end of the flask bears, holding means engaging the opposite end of the flask to press the flask against the base and hold it in position, a former, means for advancing the former through the flask in the direction from the end of the flask which is against the base toward the end of the flask engaged by the holding means to form a mold for casting in mold forming material in the flask, closure means carried by the holding means and independent operating means for the closure means, operable when the holding means are in position holding a flask against the base, to move the closure means relatively to the holding means between operative position preventing mold forming material from being ejected from the flask at the end of the flask engaged by the holding means and inoperative position to permit the former to pass out of the flask.

8. Mold forming apparatus comprising a flask, a base upon which the flask is adapted to stand in generally upright position, holding means movable into position engaging the upper end of the flask to hold the flask down against the base, a former, means for advancing the former upwardly through the flask when the flask is standing on the base to form a mold for casting in mold forming material in the flask, closure means carried by the holding means and separate actuating means, operable when the holding means are in position holding the flask down against the base, to move the closure means relatively to the holding means between operative position preventing mold forming material from being ejected from the flask at the upper end of the flask and inoperative position to permit the former to pass out of the upper end of the flask.

9. Mold forming apparatus comprising a flask, a base upon which the flask is adapted to stand in generally upright position, holding means movable into position engaging the upper end of the flask to hold the flask down against the base, a former, means for pulling the former upwardly through the flask when the flask is standing on the base to form a mold for casting in mold forming material in the flask, the pulling means passing out of the upper end of the flask, closure means carried by the holding means and disposed about the pulling means and separate actuating means, operable when the holding means are in position holding the flask down against the base, to move the closure means relatively to the holding means between operative position preventing mold forming material from being ejected from the flask at the upper end of the flask and inoperative position to permit the former to pass out of the upper end of the flask.

10. Mold forming apparatus comprising a flask, a base upon which the flask is adapted to stand in generally upright position, holding means movable into position engaging the upper end of the flask to hold the flask down against the base, a former, means for pulling the former upwardly through the flask when the flask is standing on the base to form a mold for casting in mold forming material in the flask, the pulling means passing out of the upper end of the flask, generally tubular means of smaller transverse cross section than the former disposed about the pulling means, closure means carried by the holding means and disposed about the generally tubular means and separate actuating means, operable when the holding means are in position holding the flask down against the base, to move the closure means relatively to the holding means between operative position preventing mold forming material from being ejected from the flask at the upper end of the flask and inoperative position to permit the former to pass out of the upper end of the flask.

11. Mold forming apparatus comprising a flask, a base upon which the flask is adapted to stand in generally upright position, a cylinder, means independent of the base supporting the cylinder in position spaced above the base, a generally vertically operable piston in the cylinder, the piston carrying holding means adapted upon downward movement of the piston in the cylinder to engage the upper end of the flask to hold the flask down against the base, a former, means for moving the former upwardly through the flask when the flask is standing on the base to form a mold for casting in mold forming material in the flask and generally upright tension' means connected at the bottom thereof to the base and at the top thereof to the cylinder resisting the upward reaction thrust of the cylinder when the piston is acted upon by fluid under pressure in the cylinder to press the holding means downwardly against the base so that the supporting means supporting the cylinder may be designed to carry only the static load of the cylinder and the mechanism carried thereby.

12. Mold forming apparatus comprising a flask, a base upon which the flask is adapted to stand in generally upright position, a cylinder, means independent of the base supporting the cylinder in position spaced above the base, a generally vertically operable piston in the cylinder, the piston carrying holding means adapted upon downward movement of the piston in the cylinder to engage the upper end of the flask to hold the flask down against the base, a former', means for pulling the former upwardly through the flask when the flask is standing on the base to form a mold for casting in mold forming material in the flask, the pulling means passing out of the upper end of the flask, closure means carried by the holding means and disposed about the pulling means and, when the holding means are in position holding the flask down against the base, movable relatively to the holding means between operative position preventing mold forming material from being ejected from the llask at the upper end of the flask and inoperative position to permit the former to pass out of the upper end of the tlask and generally upright tension means connected at the bottom thereof to the base and at the top thereof to the cylinder resisting the upward reaction thrust of the cylinder when the piston is acted upon by fluid under pressure in the cylinder to press the holding means downwardly against the base so that the supporting means supporting the cylinder may be designed to carry only the static load of the cylinder and the mechanism carried thereby.

13. Mold forming apparatus comprising a llask, a base against which one end of the ilask bears, holding means engaging the opposite end of the llask to press the flask against the base and hold it in position, a former, means for advancing the former through the llask in the direction from the end of the llask which is against the base toward the end of the flask engaged by the holding means to form a mold for casting in mold forming material in the flask, cylinder means carried by the holding means, piston means operable in the cylinder means and closure means carried by the piston means, the piston means being operable in the cylinder means when the holding means are in position holding a flask against the base to move the closure means relatively to the holding means between operative position preventing mold forming material from being ejected from the flask at the end of the flask enl0 gaged by the holding means and inoperative position to permit the former to pass out ofthe ilask.

14. Mold forming apparatus comprising a llask, a base against which one end of the ilask bears, holding means engaging the opposite end of the tlask to press the flask against the base and hold it in position, a former, means for advancing the former through the flask in the direction from the end of the ilask which is against the base toward the end of the llask engaged by the holding means to form a mold for casting in mold forming material in the flask, the holding means having plurality of outwardly extending arms, a cylinder carried by each arm, a piston operable in each cylinder and closure means carried by the pistons, the pistons being operable in the cylinders when the holding means are in position holding a llask against the base to move the closure means relatively to the holding means between operative position preventing mold forming material from being ejected from the llask at the end of the ask engaged by the holding means and inoperative position to permit the former to pass out of the llask.

Reterences Cited by the Examiner UNITED STATES PATENTS 289,035 11/1883 Schickle 22-17 1,272,278 7/1918 Ladd 22-17 1,299,967 4/1919 Lemoine 22-17 2,019,937 11/1935 Staples.

2,875,482 3/ 1959 Hamilton et al 22--18 FOREIGN PATENTS 544,822 2/ 1932 Germany.

26,786 12/ 1906 Great Britain.

MARCUS U. LYONS, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CRRECTION Patent No. 3,221,377 December 7, 1965 Loyal L. Johnston It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 5, after double-acting" insert a comma; column 5, line 56, for "Fuid" read Fluid line 62, strike out "sealing ring 26b and the face 27 of the hub pattern 26" and insert the same after "comprising the" in line 64, same Column 5; column 6, line 9, for "mounted" read mounting line 40, for "contaning" read containing line 6l, for "flash" read flask column 7, line 5, after "flask" strike out the period.

Signed and sealed this 18th day of October 1966.

(SEAIJ Attest:

ERNEST W. SWIDER EDWARD I. BRENNER Attesting Officer Commissioner of Patents

Claims

1. A METHOD OF FORMING A FOUNDRY MOLD COMPRISING ADVANCING COMPACTING MEANS INTO ONE END OF A FLASK CONTAINING MOLD FORMING MATERIAL TO COMPACT THE MOLD FORMING MATERIAL AT SAID END OF THE FLASK, BY THE ADVANCING COMPACTING MEANS PUSHING A TAPERED FORMER THROUGH THE MOLD FORMING MATERIAL AT SAID END OF THE FLASK TO SIMULTANEOUSLY START THE FORMER THROUGH THE FLASK AND PROVIDE GUIDANCE FOR THE FORMER AT SAID END OF THE FLASK BY THE MOLD FORMING MATERIAL COMPACTED BY THE ADVANCING COMPACTING MEANS AND FURTHER COMPACTING MOLD FORMING MATERIAL IN THE FLASK BY THE FORMER AS IT IS PUSHED BY THE COMPACTING MEANS, PULLING THE FORMER THE REST OF THE WAY THROUGH THE FLASK AND WHILE THE FORMER IS THUS