US3025578A - Fluid weight jolt molding machine - Google Patents

Description

March 20, 1962 L. F. MILLER FLUID WEIGHT JOLT MOLDING MACHINE 3 Sheets-Sheet 1 Filed March 5, 1958 MILLER OF N 0 we mL FIG. I

ATTORNEYS March 20, 1962 L. F. MILLER FLUID WEIGHT JOLT MOLDING MACHINE 3 Sheets-Sheet 2 Filed March 5, 1958 INVENTOR. LEO N F. MILL E R FIG. 2

maf flqw ATTORN BY 8 March 20, 1962 1.. F. MILLER FLUID WEIGHT JOLT MOLDING MACHINE 3 Sheets-Sheet 3 Filed March 5, 1958 m GE mm mm 5 3 ow mm INVENTOR.

LEON F.

MILLER ATTORNEYS 3,025,573 Patented Mar. 29, 1962 free 3,025,578 FLUID WEIGHT JGLT MOLDING MACHINE Leon E. Miller, Rocky River, Ohio, assignor to The born lv'lanufacturing Company, Cleveland, Ohio, a corporation of Ulric Filed Mar. 5, 1958, Ser. No. 71?,384 2 Claims. (Cl. 22-45) This invention relates as indicated to a fluid weight jolt molding machine, and more particularly to a foundry molding machine for the production of green sand molds and the like.

In the production of foundry molds and especially molds of rather large size, it has been a common practice to place a flask upon a pattern plate carried by a jolt table and, after filling such flask with sand, to jolt the same to consolidate and compact the sand against the pattern, generally following this operation with a squeezing operation against an upper squeeze head. The jolting operation is normally very noisy and requires a heavy and expensive foundation for the machine. Also, with certain types of patterns, the sand may not be as uniformly compacted against all portions of the pattern as desired. It is accordingly an important object of my invention to provide a jolt molding machine which will be much less noisy in operation and require less massive construction than in the past while nevertheless retaining the advantages of the jolting operation.

Another object is to provide such machine and a method of molding which will ensure compacting of the sand against all surfaces of the pattern in a more uniform manner than has been the case in the past.

Still another object is to provide such machine and method which will be rapid and efiicient in operation and therefore capable of large production of high quality molds.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

in said annexed drawing:

FIG. 1 is a side elevational view of a machine with parts in section embodying the principles of my invention;

FIG. 2 is a front elevational view of such machine with parts in section; and

FIG. 3 is a top plan view of such machine with parts in section.

In accordance with my invention, 1 provide a weight which is adapted to rest upon the upper surface of sand within the flask during the jolting operation, the under side of the weight being provided with a flexible diaphragm backed by a body of substantially incompressible fluid such as water completely filling the cavity containing the same. It will accordingly be apparent that when the diaphragm sags downwardly in one region, it must move correspondingly upwardly in another region, and vice versa. In effect, the weight comprises a heavy box which is open downwardly, the diaphragm closing such opening and resting on the sand surface together with the rim of the box to which the diaphragm is secured. This weight is adapted to rest freely upon the sand surface for up and down movement during the jolting operation. I am aware that it is broadly old in the art to place solid weights including bags of shot upon the sand within the flask during a jolting operation and that it is also old to perform a squeezing operation utilizing flexible fluid pressure means upon the upper surface of the sand. As will become clear from the following description, however, my new machine and method operate in a novel manner to produce a new and improved result.

Referring now more particularly to such drawing, the machine there illustrated embodying my invention may comprise a base frame 1 and four uprights 2, 3, 4 and 5 carrying a head frame 6. A conventional jolt table is mounted on the base 1 comprising a vertical cylinder 7 within which is fitted a large piston ti carrying the table proper 9 on its upper end. Such piston is adapted to be rapidly elevated and dropped by admission of pneumatic pressure through inlet 10 and release of such pressure through outlets l1 and 12. Depending guide rods 13 and 14 are sleeved in brackets r15 and 1 6 on cylinder 7 to stabilize the table during the jolting operation. An adjustable upper extension 17 of table 9 may be employed to support pattern plate 18 depending on the size flask being handled. The flask 19 rests upon such pattern plate and surrounds pattern 29 in conventional manner. A roller conveyor 21 may be provided adjacent one side of the machine for delivering an empty flask to the machine, and a similar roller conveyor 22 may be provided at the other side of the machine for removal of the flask containing the finished mold.

A draw frame 23 is supported beneath head frame 6 by rods 24 and 25 of piston- cylinder assemblies 26 and 27 respectively, such frame carrying two spaced parallel rails 28 and 29 provided with a plurality of rollers 30 and 31 adapted to engage beneath horizontal flanges 32 and 33 on the sides of flask 19 so that When the draw frame is in elevated position with rollers 30 and 31 at the same level as the rollers of roller conveyors 21 and 22, a flask may be rolled into and out of the machine.

Four vertical guide rods 34, 35, 36 and 37 are secured to draw frame 23 and are sleeved in head frame 6, the rings such as 38, 39 and 40 on the upper ends of the guide rods serving to limit downward reciprocation of the draw frame. Canting of the draw frame is further prevented by means of a link shaft 42 journalled in the head frame and having a pair of lever arms 43 and 44 keyed thereto. Links 45 and 46 pivotally connected to the ends of the respective lever arms are likewise pivotally connected to the draw frame 23 and it will accordingly be understood that such draw frame is rendered incapable of tilting longitudinally of the roller conveyor flask supporting means carried thereby.

A fill frame 47 having the same horizontal dimensions as flask 19 is adapted to be supported by end brackets 48 and 49 respectively on draw frame 23. The depth of such fill frame may, for example, be approximately onehalf the depth of flask 19.

A weight carriage 54 of general horizontal U-shape is provided with rollers such as 51, 52 and 53 for reciprocation along a horizontal trackway in head frame 6 and outboard extensions 54 and 55. The outer ends of such trackway extensions are connected by tie rod 56. Mounted on head frame 6 are a pair of horizontal pistoncylinder assemblies 57 and 58, the respective rods of which 59 and 60 connect to the forward ends of U-shaped carriage 50. Such carriage may accordingly be shuttled between a position centered above draw frame 23 and a position on the laterally oifset portion of the trackway 54, 55.

A shorter horizontal piston-cylinder assembly 61 is also mounted on head frame 6 intermediate pistoncylinder assemblies 57 and 53 and at a lower level. The piston rod 62 of piston-cylinder assembly 61 carries a horizontal crossbar 63 to the respective ends of which are attached flexible cables 64 and 65. These cables pass over pulleys 66 and 67 respectively mounted on aligned horizontal axes in the respective sides of head frame 6 and the jolt weight is suspended from the depending ends of such cables. Such jolt weight comprises a heavy horizontal rectangular steel plate 68 to which such cable ends are attached, and which plate reinforces the top of a strongly constructed steel box 69. A flexible diaphragm 76 which may be of strong rubberized fabric, for example, constitutes the underside of such box, being firmly hermetically clamped to the lower perimeter of the box. As indicated in FIG. 2, such diaphragm will very commonly bulge downwardly in one region and bulge correspondingly upwardly in another region when the box is supported out of engagement with the sand in fill frame 47 and flask 1h. The box 69 is completely filled with a liquid such as water which for the purposes of the present invention may be considered incompressible. A stack of weights 71 may be bolted to the upper surface of plate 68, the number of weights thus supplied being adjusted as desired, having regard for the particular molding operation to be performed.

As best shown in MG. 2, two sets of three roll clusters 72 and 73 are mounted on respective sides of plate 68 centrally thereof adjacent the points of attachment of cables 64 and 65 respectively. The V- rollers 74, 75, 76, 77, 78 and 79 of such clusters engage vertically extending guide rods 86 and 81 to ensure vertical reciprocation of the jolt weight assembly when the latter is raised and lowered through action of piston-cylinder assembly 61, or equally through action of the jolt table piston 8 when the weight is permitted to rest freely upon the sand within fill frame 47. The upper ends of such guide rods 80 and 31 are secured in U-shaped weight carriage Operation In the light of the foregoing description, the operation of my new machine may readily be understood. In setting up the machine, an adapter or extension 17 is placed upon jolt table 9 of proper dimensions to support the pattern plate 18 with flask l9 resting thereon, with the upper edge of such flask at a level adapted to receive the fill frame 47 deposited thereon when draw frame 23 descends. The machine is, of course, more rapid and therefore more eflicient in operation when excessive vertical reciprocation of draw frame '23 is not required.

The flask 19 is rolled onto the rollers and 31 of draw frame 23 when the latter is in elevated position so that such rollers are at the same level as the rollers of conveyor 21. The draw frame 23 is then lowered through operation of piston- cylinder assemblies 26, 27 to deposit flask 19 on pattern board 18 with the flask, of course, enclosing pattern 26. The draw frame 23 continues to descend a short distance suificient thereafter to deposit the fill frame 47 on flask 19. This final downward movement of the draw frame, of course, also lowers its rollers out of engagement with the side flanges or rails 32, 33,

on flask 19.

The jolt weight has been reciprocated to the rear of the machine during these operations and the flask and fill frame are next filled with sand by conventional means from above.

The jolt weight carriage 50 is now reciprocated from right to left as viewed in FIGS. 1 and 3 into the position there illustrated above the fill frame 47. Fill frame 47 and flask 19 will normally be of the same internal dimensions and the lower portion of the jolt weight will ordinarily be dimensioned to fit therewithin with a small amount of lateral clearance. The hydraulic diaphragm box 6h comprising the lower part of the jolt weight is lowered into the fill frame through reciprocation of piston-cylinder assembly 61, the cables 64 and 65 being permitted to go slack so that such box, and indeed the entire jolt weight, now rests freely upon the upper surface of the sand within the fill frame. The slack or 4 bulge in such cables is sufficient to accommodate all further downward movement of the jolt weight as the sand is subsequently compacted.

The conventional jolting operation is now commenced through reciprocation and dropping of piston S in cylinder 7 in the usual manner, and in a very short time the sand is firmly compacted against the pattern 20. While it is normally preferred thus to commence the jolting operation after the jolt weight is freely resting upon the upper sand surface, it is occasionally advantageous to commence the jolting operation before the weight is rested upon the sand, particularly when very deep molds are to be made. The sand within fill frame 47 will ordinarily be of a depth such that when it is fully compacted against the pattern within the flask, the upper level of the sand will now be generally co-planar with the upper edge of the flask. It is well known and will be readily understood that the sand tends to compact more quickly and readily in the regions adjacent the higher portions of the pattern, and consequently the sand may in normal operation be relatively inadequately compacted against the lower portions of the pattern. This is true even when a jolt weight is employed resting upon the upper surface of the sand, where such jolt Weight is provided with a rigid under surface although the situation may sometimes be improved by the provision of downward projections on the underside of the jolt weight. In accordance with my invention, however, the diaphragm 70 will tend to be depressed downwardly into the flask in those regions where the depth of sand is relatively great and the diaphragm will be correspondingly elevated in other regions where the resistance to further compacting is enhanced by relatively high portions of the pattern. Inasmuch as the cavity within the box 69 is entirely filled with an incompressible liquid, it will be seen that the pressure against any portion of the diaphragm must always be the same as that against any other portion of such diaphragm. Of course, the liquid within box 69 also itself comprises a very considerable part of the jolt weight.

After the jolting operation has been concluded, pistoncylinder assembly 61 is actuated to lift the jolt weight up into the embrace of horizontal U-shaped carriage 50, and such carriage is then reciprocated to the right as viewed in FIGS. 1 and 3 to avoid obstructing the subsequent drawing operation and also to permit the filling of another flask with sand when the next cycle of operation is inaugurated.

After the jolt weight has been reciprocated out of the way, the draw frame 23 is reciprocated upwardly through actuation of piston- cylinder assemblies 26 and 27. Brackets 48 and 49 on the draw frame first pick up the fill frame 47, lifting it slightly above flask 19. The rollers 30 and 31 of the draw frame next pick up the flask 19 and lift the latter into position to be rolled out on conveyor 22. As the flask is thus elevated, the operation being steadied by draw guide rods 34, 35, 36 and 37, the mold is drawn from pattern 20. As soon as the flask with the finished mold therein is pushed from the machine onto adjacent conveyor 22, another flask may be run into the machine and a new cycle commenced.

It will be appreciated that the flexible diaphragm 70 is to some extent distensible in order to conform very generally to the contour of the pattern as the sand is compacted against the latter. Since the liquid filled cavity is both completely filled and sealed, however, the average level of the diaphragm relative to the body of the weight will remain uniform, one portion of the diaphragm being forced to rise when another portion descends. The rigid peripheral wall of the cavity, of course, also rests upon the upper surface of the sand and will normally fit reasonably closely within the confines of the flask (and fill frame), this being a region where the pattern normally does not extend.

While I normally employ the usual jolting operation, this proves to be considerably less noisy and objectionable than in the past due to the provision of my new weight means, and there is less shaking of the surroundings. Of course, an important advantage resides in the fact that a supplemental squeezing operation is ordinarily not needed, and consequently the frame of the machine may be much less rugged and expensive than in the past. The various fluid pressure cylinders illustrated and described above will ordinarily be operated by compressed air to obtain a rapid cycle and in view of the common availability of compressed air in foundries. Other fluid pressure means or indeed mechanical devices such as rack and pinion means may, however, be employed where suitable and desired. While a jolting operation is contemplated, it will likewise be understood that on occasion a strong vibratory action will suflice and is considered to be included within the scope of the term jolting as employed herein and in the claims.

Other modes of applying the principle of the invention may be employed, change being made a regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a foundry molding machine having a vertically reciprocable jolt table, means operative thus to reciprocate said table to jolt the same together with a pattern and flask supported thereon, and a weight positioned to rest freely bodily upon sand in such flask to enhance the sand compacting effect of such jolting operation; means mounting said weight for reciprocation horizontally into and out of position above said flask, means operative to lower said weight upon such sand to rest freely thereon, a fill frame adapted to rest upon the upper edge of said flask, the lower portion of said weight being dimensioned to fit therewithin, a vertically reciprocable draw frame adapted to engage and lift said flask to draw a completed mold from the pattern, said draw frame also being operative to lift said fill frame clear of said flask, rollers on said draw frame adapted to support said flask for horizontal movement onto and off of said draw frame, power means operative vertically to reciprocate said draw frame; said weight having a large cavity in its under side, a flexible diaphragm closing such cavity and adapted to rest upon the upper surface of such sand, and a liquid completely filling such cavity and sealed therewithin.

2. In a foundry molding machine having a vertically reciprocable jolt table, means operative thus to reciprocate said table to jolt the same together with a pattern and flask supported thereon, and a weight positioned to rest freely bodily upon sand in such flask to enhance the sand compacting effect of such jolting operation; a carriage mounted for reciprocation horizontally into and out of position above said flask, piston-cylinder means operative thus to reciprocate said carriage, flexible means supporting said weight depending from said carriage, piston-cylinder means operative to retract and extend said flexible means to raise and lower said weight, vertical guide means on said carriage effective to guide such vertical movement of said weight, a fill frame adapted to rest upon the upper edge of said flask, the lower portion of said weight being dimensioned to fit therewithin, a vertically reciprocable draw frame adapted to engage and lift said flask to draw a completed mold from the pattern, said draw frame also being adapted to lift said flll frame clear of said flask, rollers on said draw frame adapted to support said flask for horizontal movement onto and off of said draw frame, piston-cylinder means operative vertically to reciprocate said draw frame, control means effective to ensure precise straight-line reciprocation of said draw frame; said weight having a large cavity in its under side, a flexible distensible diaphragm closing such cavity and adapted to rest upon the upper surface of such sand, and a liquid completely filling such cavity and sealed therewithin.

References Cited in the file of this patent UNITED STATES PATENTS 631,494 Adams Aug. 22, 1899 697,385 Adams Apr. 8, 1902 1,545,420 Frazer July 7, 1925 1,816,774 Grindal July 28, 1931 2,142,491 Byerlein Jan. 3, 1939 2,255,988 Shanley Sept. 16, 1941 FOREIGN PATENTS 10,436 Great Britain of 1884

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