US3289256A

US3289256A - Mold compacting apparatus

Info

Publication number: US3289256A
Authority: US
Publication date: 1966-12-06
Anticipated expiration: 1983-12-06

Description

D

6, 1 B. c. FERRIS 3,289,256

MOLD COMPACTING APPARATUS Filed Nov. 16, 1964 5 Sheets-Sheet 1 2 O O O 40 /4 INVENTORL 770 KAI 5X5 Dec 6, 1966 B. c. FERRIS MOLD COMPACTING APPARATUS 5 Sheets-Sheet 2 Filed NOV. 16, 1964 5 2 M 4 my W 2 4 a l n 2 u a ,0 3m M v J ZJ I H A I a ,X M/ 4. x L00 6 06 0 j w\/j g \m Dec. 6, 1966 Filed NOV. 16, 1964 B. C. FERRIS MOLD COMPACTING APPARATUS 5 Sheets-Sheet 5 United States Patent Ofiice 3,289,256 Patented Dec. 6, 1966 3,289,256 MOLD COMPACTING APPARATUS Burton C. Ferris, Detroit, Mich., assignor to Kelsey- Hayes Company, a corporation of Delaware Filed Nov. 16, 1964, Ser. No. 411,340 8 Claims. (CI. 22-42) This invention relates generally to molding apparatus, and more particularly, to an improved apparatus for fabricating sand molds.

It has heretofore been proposed in the fabrication of sand molds of the type used in casting various metals, metallic alloys and the like, to compact the mold sand around a mold pattern by forcing a resilient and deformable diaphragm or blanket against the sand by a source of compressed air or similar actuating fluid. This method, however, has been objectionable due to the fact that the portion of the mold against which the diaphragm or blanket is compressed (usually the bottom), is formed with an irregular or nonplanar surface, resulting from variations in the amount the mold sand is compacted around the mold pattern. Accordingly, when sand molds that have been formed by the aforesaid method are inverted in preparation for a subsequent casting operation, the lower sides thereof nonuniformly bear against an associated support surface, whereby cracks and undesirable similar discontinuities occur in the molds. This, of course, results in considerable replacement expense and interferes to some extent with the production schedule of the foundry.

It is accordingly a general object of the present invention to provide an improved compacting apparatus for fabricating sand molds that are not subjected to the aforedescribed objections.

It is a more particular object of the present invention to provide an apparatus for fabricating sand molds that have substantially flat or planar bottom or lower sides which are adapted to uniformly bear upon an associated support surface.

It is still a more particular object of the present invention to provide an improved sand mold compacting apparatus which includes means for striking off the lower sides of the compacted molds, thereby forming a substantially fiat or planar surface upon which the molds may be supported during a subsequent casting operation.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a fragmentary cross sectional view of the mold compacting apparatus of the present invention;

FIG. 2 is a view similar to FIGURE 1 and illustrates the manner in which mold sand is transmitted from the sand hopper to the mold flask during the operational cycle of the present invention;

FIG. 3 is a fragmentary cross sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is an enlarged view of a portion of the structure illustrated in FIG. 3;

FIG. 5 is a side elevational view taken along the line 5-5 of FIG. 4;

FIG. 6 is a fragmentary side elevational view of the structure illustrated in FIG. 5, taken along the line 66 thereof, and

FIG. 7 is a horizontal cross sectional view taken along the line 77 of FIG. 4.

Referring now to the drawings, a mold compacting apparatus 10 in accordance with a preferred embodiment of the present invention, is shown in operative association with a molding sand dispensing apparatus 12 which serves to selectively dispense predetermined quantities of mold ing sand that is subsequently compacted by the apparatus 10, as will hereinafter be described.

The sand dispensing apparatus 12 comprises a support structure 14 upon which is mounted an open top sand hopper 16 that is adapted to contain a supply of molding sand for the compacting apparatus 10.. Reciprocally mounted on the structure 14 directly below the lower end of the hopper 16 is a generally rectangularly shaped batch hopper 18 which is movable along a horizontal track or rail 19 upon actuation of a piston and cylinder assembly, generally designated 20, from a position directly beneath the hopper 16 as seen by the phantom lines in FIGURE 1, to a position spaced away from the hopper 16 as illustrated by the solid lines in FIGURE 1. The batch hopper 18 comprises a shutter plate 22 which projects horizontally from the upper end thereof and serves to close the lower end of the hopper 16 when the batch hopper 18 is biased by the assembly 20 to the position illustrated by the solid lines in FIGURE 1. The lower end of the batch hopper 18 is closed by a horizontally extending drawer 24 which is reciprocably mounted on the batch hopper 18 and is movable relative thereto by a suitable piston and cylinder assembly, generally designated 26. The drawer 24 serves to selectively open and close the bottom of the batch hopper 18 to discharge the molding sand desposited th-erewithin by the hopper 16, as will be described.

The support structure 14 includes a horizontally extending conveyor platform, generally designated 28, upon which is supported a series of generally rectangular configured molding flasks, generally designated by the numeral 30. The flasks 30 are open on their top and bottom and are successively conveyed to a position substantially underlying hopper 16 by means of a conventional conveying apparatus (not shown), from which position they are adapted to be individually conveyed to a flask lowering mechanism that is generally designated 32 and located at the right end of the support structure 14. The flasks 30 are conveyor to the lowering mechanism 32 by means of a plurality of flask engaging dogs 34- which depend downwardly from the piston and cylinder assembly 26 and are adapted to engage each individual flask 30 as it is positioned beneath the hopper 16.

The flask lowering mechanism 32 comprises a roller platform 36 having a plurality of antifrictional rollers 38 mounted on the opposite sides thereof which enable the successive flasks 30 to be easily biased onto the platform 36 by the dogs 34. Extending between the lower side of the platform 36 and the lower end of the support structure 14 is a pair of upwardly or vertically extending piston rods 40 and 42 which serve to elevate and lower the platform 36 upon actuation of a pair of

cylinder assemblies

44 and 46 which are operatively associated with the piston rod members 40 and 42, respectively.

Upon lowering the platform 36, as by retracting the piston rod members 40 and 42 within their associated

cylinder assemblies

44 and 46, the molding flask 30 which is supported on the top of the platform 36 is lowered onto a carriage car 48 which has rollers 50 on the opposite side thereof that are slidable upon a pair of spaced parallel rails or tracks 52 which extend perpendicularly to the aforediscussed conveying platform 28 and enable the carriage car 48 to move from its position illustrated in solid lines in FIGURE 3 to a position within the compacting apparatus 10, as indicated in the phantom line in FIGURE 3. Referring again to FIGURES 1 and 2, the carriage car 48, together with supporting the individual molding flasks 30 thereon, is adapted to support one or more reusable mold patterns, representatively designated by the numeral 54 and around which the molding sand deposited from the batch hopper 18 into the flasks 30- is compacted to form a sand mold.

Referring now in detail to the mold compacting apparatus 10 of the present invention, as seen in FIG- URES 3 and 4, the apparatus 10 comprises an enclosed upper end or head section 56 which is generally rectangular in horizontal section and has a top portion 58, side portions 60 and defines a manifold chamber 62 therewithin. The bottom of the section 56 is communicable through a plurality of ports 64 with a diaphragm chamber 66 which is also generally rectangular in horizontal section and is located directly below the head section 56, as seen in FIGURES 3 and 4.

Extending across and being sealingly secured around the periphery of the lower end of the chamber 66 is a compacting diaphragm or blanket 68 which is preferably fabricated of a flexible and deform-able material such as rubber or the like and serves to compact the molding sand with the flasks 30, in a manner hereinafter to be described.

Air or a similar actuating fluid is supplied under pressure to the manifold chamber 62 through a valve mechanism 70 and an air conduit 72, the latter of which is connected to a suitable source of compressed air, representatively indicated by the air pump 74. The valve mechanism 70, which is mounted on the top of head section 56, is preferably of the three way two-position type and includes a conventional solenoid device (not shown) which is adapted to selectively communicate the manifold chamber 62 with the air conduit 72 or with conduit 76 which is communicable with a vacuum pump herein designated 78. As best seen in FIGURE 4, a flat horizontally extending baffle plate 80 is secured to the top of the diaphragm chamber 66 below the ports 64, which plate 80 serves to diffuse or disperse the force of pressurized air or similar actuating fluid being communicated into the chamber 66 from the manifold chamber 62 to force the diaphragm 68 downward and thereby compact the molding sand Within the flasks 30.

Referring now to FIGURES through 7, the lower end of the mold compacting apparatus (that portion below the diaphragm chamber 66) is generally C-shaped in horizontal cross section and comprises spaced side portions 82 and 84 and a back portion 86, the remaining open side confronting the mold sand dispensing apparatus 12. As seen in FIGURE 3, the carriage car tracks 52 terminate within the apparatus 10 and thus permit the carriage car 48, along with a flask and mold pattern 54 supported upon the car 48, to move from a position underlying dispensing apparatus 12 to a position within the compacting apparatus 10. Means for thus moving the carriage car 48 along the tracks 52 is achieved through the use of a piston and cylinder assembly, generally designated 88, which is located substantially below the apparatus 10 and comprises a reciprocal piston rod 90. The piston rod 90, which extends parallel to and interjacent the tracks 52, is provided with a carriage car engaging mechanism 92 on the outer end thereof that is connected to the lower side of the carriage car 48, as seen in FIGURES 3 and 4. Upon actuation of assembly 88, the piston rod 90 will bias the carriage car 48 along the tracks 52 from the position illustrated by the solid lines in FIGURE 3 into the interior of the compacting apparatus 10, at which time the compacting diaphragm 68 is forced downwardly to compact the molding sand within the flask 30 supported upon the carriage car 48. Upon completion of the compacting operation, the piston rod 90 then biases the carriage car 48, along with the flask 30 and compacted sand mold therein, out of the apparatus 10 in preparation for the next successive compacting operation.

To prevent the molding sand from being forced out of the interior of the apparatus 10 through the open side thereof when the diaphragm 68 is forced downwardly onto the flask 30 and molding sand disposed therewithin, there is provided a horizontally extending, elongated gate, generally designated 94, which is movable to and from a position closing that portion of the open side of the compacting apparatus 10 directly adjacent the top of the flasks 30 when they are located Within the apparatus 10. The gate 94, when disposed in the above described position partially closing the open side of the apparatus 10, is supported by a pair of rectangularly shaped support brackets, generally designated 95 having rectangularly shaped openings 96 within Which the gate 94 is slidably mounted, as seen in FIGURE 6. The upset gate 94 is opened and closed through the use of a piston and cylinder assembly, generally designated 97, which is secured to one end of the apparatus 10 by a suitable bracket 98 and comprises a reciprocal piston rod 100 that is secured at its outer end to the end of the gate 94 by a plurality of bolts, generally designated 102.

In accordance with the principles of the present invention, the apparatus 10 includes a molding sand strikeoff mechanism, generally designated 104, which serves to strike off or level the top of the compacted sand molds as the carriage car is moved out of the apparatus 10 upon actuation of the piston and cylinder assembly 88. The mechanism 104 is located on the open side of the aparatus 10 and comprises a horizontally extending strikeoff bar 106 having a shearing edge 108 formed along the lower side thereof. The bar 106 is movable in a substantially vertical direction from a position where the shearing edge 10% thereof is slightly higher than the top of the gate 94, thus permitting the flasks 30 to move freely intothe apparatus 10 on the carriage car 48, to a position where the shearing edge 108 thereof lies in substantially the same horiozntal plane defined by the top of the molding flasks 30 when they are located within the apparatus 10. Thus, as the flasks 30 are moved out of the apparatus 10 relative to the strike-ofl bar 106, the portions of the compacted sand molds projecting above the horizontal plane defined by the top of the flasks 30 will he sheared off of the top of the flasks 30 by the shearing edge 108, whereby the bottom of the sand molds will have a flat or planar surface upon which they may be supported without the possibility of the sand molds cracking or the like. Means for moving the strike-off bar 106 to and from the above described position coplanar with the top of the flasks 30 is provided by a piston and cylinder assembly 110 that is mounted near the top of the apparatus 10 by a suitable support bracket 112. The assembly 110 includes a reciprocal piston rod 114 which is secured to a medial portion of the strike-off bar 106 by a suitable retaining bracket 116 and bolts 118, as seen in FIGURE 5.

To facilitate the correlation of the various hereinabove described components of the mold compacting apparatus 10, together with their operative association with the sand dispensing apparatus 12, a brief resume of the operation of each of these devices will now be given.

In operation, assuming that the hopper 16 contains an adequate supply of molding sand and that a continous supply of flasks 30 are conveyed along the platform 28, and also that the batch hopper 18 is oriented below hopper 16 such that a predetermined quantity of molding sand passes from the hopper 16 into the batch hopper 18, the piston and cylinder assembly 20 is initially energized whereby the batch hopper 18 moves from the position illustrated in the phantom lines of FIGURE 1 to the position illustrated by the solid lines in this figure. It will be noted that as the batch hopper 18 is thus moved, the shutter plate 22 closes the lower end of the hopper 16 to prevent any mold sand from being dispensed from the hopper 16 until such time as the batch hopper 18 is again oriented therebelow. As the batch hopper 18 is thus moved by the assembly 20, the flask 30 which is oriented below the hopper 16 is moved by the dogs 34 onto the top of the platform 36. When the flask 30 is moved onto the platform 36, a suitable limit switch (not shown) is actuated, whereby the cylinder assemblies 44 and 46 are energized to lower the piston rods 40 and 42 such that the flask 30 is deposited onto the top of the carriage car 48 having the mold pattern 54 supported thereon. When the flask 34} is thus located on the top of the carriage car 48, the piston and cylinder assembly 26 is actuated whereby the drawer 24 is moved to the left, thereby enabling the molding sand within the batch hopper 18 to drop downwardly into the flask 30, as seen in FIGURE 2.

Assuming that the gate 94 is in the position illustrated in the pahntom lines in FIGURE 7 and that the strikeofr bar 106 is in a raised position, after the molding sand is deposited into the flask 30, the piston and cylinder assembly 88 is actuated, whereby the piston rod 90 thereof biases the carriage car 48, along with the flask 30, pattern 54 and molding sand into the compacting apparatus of the present invention. As the carriage car 48 is moved into position within the apparatus 10, it trips a suitable limit switch (not shown) which serves to actuate the piston and cylinder assembly 97, whereby the gate 94 is biased to its closed position, as indicated by the solid lines in FIGURE 7. When the gate 94 is thus closed, the valve mechanism 70 is actuated such that compressed air or the like is forced from the pump 74 into the manifold chamber 62, this air then being communicated through the ports 64 into the diaphragm chamber 66 to force the diaphargm 68 downwardly against the top of the molding sand within the flask 30, as seen in FIGURE 4. As the diaphragm 68 is forced downwardly by the compressed air within the chamber 66, the molding sand is compacted within the flask 3i and around the pattern 54 therein, the degree of compacting of the sand, of course, depending upon the air pressure within the chamber 66.

At such time as the compacting operation is completed, the valve mechanism 70 is again actuated, for example, by a suitable pressure sensing device within the diaphragm chamber 66, whereby the interior of the manifold chamber 62 and diaphragm chamber 66 are communicated through the conduit 76 with the vacuum pump 78, resulting in the pressurized air or the like within the chambers 62 and 66 being evacuated therefrom and the diaphragm being elevated to the position illustrated in FIG- URE 3. As the pressurized air within the chamber 62 and 66 is thus evacuated, the piston and cylinder assembly 97 is actuated, thereby retracting the piston rod 100 and opening gate 94. Simultaneously, the piston and cylinder assembly 110 is actuated whereby the strikeoff bar 106 is lowered to the position illustrated by the phantom lines in FIGURE 4. Thereafter, the piston and cylinder assembly 88 is actuated whereby the piston rod 90 biases the carriage car 48 out of the apparatus 10, at which time the shearing edge 106 of the bar 106 shears or strikes oif that portion of the molding s-an-d which projects above the top of the molding flask 30, thereby providing a smooth or planar surface along the top of the sand mold theretofore formed within the flask 30. Accordingly, when the sand mold is removed from the flask and properly inverted such that cavities formed by the pattern 54 face upwardly for receiving the material to be cast therewithin, the lower surface of the sand mold will contiguously bear upon a suitable support platform such that the sand mold will be properly supported thereon.

When the carriage car 48 been biased out of the compacting apparatus 10 to the position indicated by the solid lines in FIGURE 3, the flask 3t), together with the sand mold formed therewithin, is removed from the top of the car 48 by suitable conveying means (not shown). It will be note-d that the pattern 54 may be fixedly secured to the top of the car 48 and thereby remain on the car 48 when the flask 30 and sand mold is lifted therefrom, or alternatively, the pattern 54 may be removed with the sand mold and flask and. be replaced by similar or different patterns in preparation for the next operational cycle of the compacting apparatus 10. After the flask 30 and sand mold are removed from the car 48, the piston and cylinder assembly 110 is actuated to raise the strike-off bar 106, the piston and

cylinder assemblies

44 and 46 are actuated to raise the roller platform 36, the assembly 26 is actuated to close the shutter plate 24, and the assembly 20 is actuated. to bias the batch hopper 18 to a position underlying hopper 16, whereby the compacting apparatus 10 and molding sand dispensing apparatus 12 are prepared for the next successive operational cycle thereof.

While it will be apparent that the preferred embodiment herein illustrated is well calculated to fulfill the objects above stated, it will be appreciated that the mold compacting apparatus 10 of the present invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined, claims.

What is claimed is:

1. In combination with a sand dispensing apparatus, a sand mold flask containing a preselected quantity of molding sandv therewithin, means defining a generally three-sided enclosure for receiving said flask, means including a pressure responsive diaphragm within said enclosure for compacting sand within said flask to form a mold, gate means mounted on said enclosure and movable to and from a position forming the fourth side thereof, and mold shearing means, said mold being engageable with and said. last mentioned means as the mold is moved out of the apparatus whereby to form a substantially planar surface on at least a portion of said mold.

2. The invention as set forth in claim 1 which includes means for moving said flask relative to said mold shearing means.

3. In combination with a sand dispensing apparatus, a mold campacting housing having an opening on one side thereof adapted to removably receive a molding flask, gate means slidably mounted on said housing for selectively closing at least a portion of said opening, means within said housing including fluid pressure responsive diaphragm means for compacting a mold within said molded flask, a strike-off bar movably secured on said housing, and means for moving said strike-off bar to and from a position in substantial coplanar relation with a portion of said molding flask.

4. In combination in a molding apparatus, a semienclosed molding housing adapted to removably receive a molding flask containing a preselected quantity of molding sand means for moving a molding flask along a pre selected path to and from the interior of said housing, means including gate means movable transversely to said path for partially enclosing said flask within said housing, means including diaphragm means for compacting said sand. within said flask, and mold shearing means, said flask and said last mentioned means being movable to one another whereby to provide a substantially planar surface on at least a portion of a mold formed in said flask.

5'. In a mold compacting apparatus, a housing having an opening formed therein for removably receiving a molding flask, means including pressure responsive diaphragm means for compacting molding sand within said flask, means for partially closing said opening, a mold shearing bar movably mounted on said housing, gate means movable parallel to said bar for at. least partially closing said opening, and means for moving said flask relative to said bar whereby to form a substantially planar surface on at least a portion of a mold formed in said flask.

6. In a mold compacting apparatus, a compacting housing, a fluid pressure responsive diaphragm in said housing, an opening in said housing adjacent said diaphragm and adapted to removably receive a molding flask containing a preselected quantity of molding sand, means for forcing said diaphragm into engagement with molding sand with a molding flask disposed in said housing to compact the sand, means including gate means for at least partially closing said opening, means movable relative to said flask and engageable with the compacted sand to provide a substantially planar surface on a portion of the mold formed therewithin, and means for moving said flask along a path transverse to the axis of said last mentioned means.

7. In a mold compacting apparatus, a housing comprising a manifold. chamber and a diaphragm chamber, a substantially flexible and deformable diaphragm extending within said diaphragm chamber, an opening in said housing adjacent said diaphragm, a molding flask containing a preselected quantity of molding sand, means including carrier means for transporting said flask into and out of said opening, means for subjecting said diaphragm to fluid under pressure to press said diaphragm against said sand in said flask to compact said sand, a gate slidably mounted. on said housing and movable to and from a position partially closing said opening, a horizontally extending strike-off ba-r movably secured to said housing adjacent said opening and movable to and from a plane parallel to a plane defined by said flask, and piston and cylinder means for raising and lowering said strike-off bar and for opening and closing said gate.

8. The invention as set forth in claim 7 which includes piston and cylinder means for biasing said carrier mean-s relative to said strike-off bar whereby said bar engages a sand mold in said flask to form a substantially planar surface thereon.

References Cited by the Examiner UNITED STATES PATENTS 1,134,398 4/1915 McCarte 2242 X 2,588,669 3/1952 Taccone 2242 2,698,976 1/1955 Taccone 22-42 2,859,499 11/ 1958 Floehr 2242 I. SPENCER OVERHOLSER, Primary Examiner.

20 E. MAR, Assistant Examiner.

Claims

5. IN A MOLD COMPACTING APPARATUS, A HOUSING HAVING AN OPENING FORMED THEREIN FOR REMOVABLY RECEIVING A MOLDING FLASK, MEANS INCLUDING PRESSURE RESPONSIVE DIAPHRAGM MEANS FOR COMPACTING MOLDING SAND WITHIN SAID FLASK, MEANS FOR PARTIALLY CLOSING AND OPENING, A MOLD SHEARING BAR MOVABLY MOUNTED ON SAID HOUSING, GATE MEANS MOVABLE PARALLEL TO SAID BAR FOR AT LEAST PARTIALLY CLOSING SAID OPENING, AND MEANS FOR MOVING SAID FLASK RELATIVE TO SAID BAR WHEREBY TO FORM A SUBSTANTIALLY PLANAR SURFACE ON AT LEAST A PORTION OF A MOLD FORMED IN SAID FLASK.