US3648759A

US3648759A - Machine for making sand molds

Info

Publication number: US3648759A
Application number: US4606A
Authority: US
Inventors: Robert Lund; Vernon Koss
Original assignee: Pettibone Corp
Current assignee: Pettibone Corp
Priority date: 1970-01-21
Filing date: 1970-01-21
Publication date: 1972-03-14
Anticipated expiration: 1989-03-14
Also published as: CA928929A

Abstract

A machine for simultaneously producing cope and drag sand mold sections and embodying vertically movable flask parts including an upper part, a lower part, and an intermediate pattern part (match plate assembly). The lower and intermediate parts are brought together to define a lower pattern-enclosing flask cavity while the upper and intermediate parts are brought together to define an upper pattern-enclosing cavity. Both cavities are simultaneously filled with sand and the sand simultaneously squeezed to produce upper and lower mold sections, after which the parts are separated, the intermediate part withdrawn, the upper and lower parts moved into contiguity to unite the mold sections, and the upper and lower parts widely separated to afford clearance so that the united upper and lower mold sections may be pushed laterally from the machine.

Description

lllhitod Mateu Patent Lunol et al,

[ Mar M, W72

[54] MACll'llllNlE 1Fllt MAllfillNG SAND ll/llUlLlUS [72] Inventors: llTohert laundl, Elmhurst; Vernon ltoae,

Niles, both of Ill.

{7 3] Assignee: lP'ettihone Corporation, Chicago, Ill.

[22] Filed: Jan. 21, 1970 211 App]. No.: aooo 3,229,336 1/1966 Hunteret al ..164/195 Primary EmminerRobert D. Baldwin Attorney-l lotman H. Gerlach [57] AMSTMCT A machine for simultaneously producing cope and drag sand mold sections and embodying vertically movable flask parts including an upper part, a lower part, and an intermediate pattern part (match plate assembly). The lower and intermediate parts are brought together to define a lower pattern-enclosing flask cavity while the upper and intermediate parts are brought together to define an upper pattem-enclosing cavity. Both cavities are simultaneously filled with sand and the sand simultaneously squeezed to produce upper and lower mold sections, after which the parts are separated, the intermediate part withdrawn, the upper and lower pans moved into contiguity to unite the mold sections, and the upper and lower parts widely separated to afford clearance so that the united upper and lower mold sections may be pushed laterally from the machine.

5 (flaunts, 26 Drawing Figures lo O O Q O O O SHEET l 1F 7 PATENTEDMA 14 1972 AHorney VERNON I K055 PATENTEUMAR 14 I972 SHEET 5 UF 7 5 M T m M we 3 $1.0 my am 7 00 m P 2 3 m u 3 2 M J T PM!" u .1 ||bl Jaw]? Bu l fill! P l HI- n I L ll 0 g 3 a L I I 4 M I E m m m m w W a 0 W L 4 ROBERT LU/VD AHorney MACHINE IF 011i MAKING SAND MOIIIDS The present invention relates generally to machines for making sand molds and has particular reference to a foundry machine which is capable of simultaneously producing the cope and drag sections of a composite sand mold, the two sections being complete and assembled upon each other and ready for a molten metal pouring operation at the time they leave the machine.

The invention is particularly concerned with sand mold forming machines of the general type which is shown and described in U.S. Pat. No. 3,229,336, granted on Jan. 18, 1966 and entitled MATCH PLATE MOLDING MACHINE FOR THE SIMULTANEOUS PRODUCTION OF COPE AND DRAG MOLD SECTIONS, the present mold making machine being an improvement on the machine of said patent.

The objects of the present invention are, in general, the same as those set forth in the preamble of the specification of aforementioned U.S. Pat. No. 3,229,336, and the present machine is similar to the patented machine in that both machines make provision for the simultaneous performance of blow and squeeze operations in flask sections which are disposed on opposite sides of a pattern plate, utilizing a vertical in-line arrangement of flask parts and flask motions with the exception of the match plate assembly movement which takes place in a lateral direction for projection of the assembly into and withdrawal of the plate out of the working area of the machine. The improvements which are embodied in the present machine are manifold and until a more complete understanding of the nature and operation of the present machine has been attained, a brief statement of the principal differences in structure and machine operation will suffice.

The principal structural difference between the patented machine and the mold making machine of the present invention resides in the matter of sand-filling operations which are performed upon the upper and lower pattern enclosing flask cavities. Whereas in the patented machine a single sand magazine is employed with dual blow slots for simultaneously introducing sand by a blow operation through the side walls of the upper and lower cavity-defining flask sections, in the present machine separate sand magazines are employed, one magazine having a single blow slot which serves the lower flask cavity through a side wall thereof, and the other magazine having multiple blow slots which serve the upper flask cavity through the top wall thereof. A further structural difference resides in the fact that in the present machine, the aforementioned top wall of the upper flask section is a fixed member which functions both as a squeeze plate and a blow plate, whereas in the patented structure it is vertically movable and functions only as a squeeze plate.

Other important structural differences between the present machine and the patented machine reside in the manner in which relative flask movements are initiated, the present machine employing a relative massive compound concentric piston and cylinder arrangement for actuating the lift table which controls the movements of the lower flask section and the associated lower squeeze plate, whereas the patented machine employs multiple, laterally distributed individual piston and cylinder devices which are subject to the production of binding stresses between the vertically movable parts which are to be raised and lowered with consequent misalignment of the flask sections.

The present machine embodies an entirely different mode of match plate assembly projection into and withdrawal from the working area of the machine, straight line lateral movement of this match plate assembly being resorted to in place of arcuate swinging movement thereof as employed in the patented machine.

A novel hopper and sand gate construction by means of which the two sand magazines are supplied with sand, novel means for ejecting the completed sectional sand mold from the machine, and novel facilities for depositing the successive composite sand molds which are ejected onto individual bottom boards and conducting them away from the machine are further features of the present mold making machine.

The provision of a sand mold forming machine such as has briefly been outlined above constitutes the principal objects of the present invention. Numerous other objects and advantages of the invention will become apparent as the following description ensues.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by the claims at the conclusion hereof.

In the accompanying sevensheets of drawings forming a part of this specification, one illustrative embodiment of the invention is shown.

In these drawings:

FIG. I is a front elevational view of a match plate sand mold making machine embodying the principles of the present invention, the various parts of the machine being shown in the positions which they assume at the commencement of a machine cycle;

FIG. 2 is a side elevational view of the machine which is illustrated in FIG. ll;

FIG. 3 is an enlarged side elevational view of the sand gate and its associated instrumentalities, the view being taken in the direction of the arrows identified with the line 3-3 of FIG. 1;

FIG. 4 is a fragmentary side elevational view in the vicinity of the line 4-4 of FIG. 3 and in the direction of the arrows, a portion of the sand gate casing being broken away in order more clearly to illustrate a sand gate which is associated with the sand magazine of the machine;

FIG. IA is a fragmentary view similar to FIG. 4 but showing the sand gate in its open position;

FIG. 5 is an enlarged horizontal sectional view taken on the line ofFIG. 2;

FIG. 6 is an enlarged sectional view taken on the line 6--6 of FIG. 1;

FIG. 7 is a perspective view of one of a series of screen units which are employed in connection with the invention;

FIG. 7A is a sectional view taken on the line 7A-7A of FIG. '7;

FIG. 8 is an enlarged vertical sectional view taken on the line h-h of FIG. 2, portions of the machine being shown in elevation;

FIG. 9 is a sectional view similar to FIG. 8 but showing the flask parts in the positions which they assume during the sand squeeze portion of the machine cycle;

FIG. It) is an enlarged vertical sectional view taken on the line lid-I0 of FIG. 9 and showing the flask parts in their squeeze position;

FIG. Ill is an enlarged fragmentary side elevational view of the transfer mechanism which is employed in connection with the invention;

FIG. 12 is a side elevational view similar to FIG. 11 but with the frame of the match plate assembly being shown in its retracted position;

FIG. I3 is a fragmentary side elevational view of a board feeder mechanism which is employed in connection with the invention;

FIGS. 14 to 21, inclusive, are schematic sectional views taken centrally and vertically through the flask parts and illustrating sequential positions thereof throughout one complete machine cycle, these positions being:

a. the start position of FIG. 14;

b. the blow position of FIG. 15;

c. the squeeze position of FIG. 16;

d. the draw position of FIG. 17;

e. the transfer position of FIG. 18;

f. the closed position of FIG. 19;

g. the mold-release or strip-out position of FIG. 20; and

h. the mold-eject position of FIG. 21;

FIG. 22 is a side elevational view of a lift table assembly which is employed in connection with the present invention;

FIG. 23 is a vertical sectional view taken substantially on the line 23-23 of FIG. 22 and illustrating the hydraulic drive mechanism which is associated with the lift table assembly of FIG. 22', and

FIG. 24 is an enlarged vertical sectional view taken substantially on the line 24-24 of FIG. 23.

BRIEF DESCRIPTION OF THE MACHINE Referring now to the drawings in detail and in particular to FIGS. 1, 2, 8 and 9, one exemplary form of an automatic sand mold making or forming machine embodying the principles of the present invention is designated in its entirety by the reference numeral 10 and is shown as being operatively installed upon a suitable foundation surface such as a foundry floor 12 or the like.

Briefly, the mold forming machine 10 involves in its general organization, a fixed framework, various portions of which are identified by the reference numeral 14 wherever they appear throughout the drawings. The machine further includes an upper cope flask section 16 (see FIGS. 8 and 9), a lower drag flask section 18, and an intermediate match plate assembly 20 for supporting upper and lower patterns 21 and 22, together with mechanism for handling the two flask sections and the match plate assembly in a cyclic manner to the end that the empty flask sections may be first brought into operative engagement with the match plate assembly by a clamp operation, then the two flask sections filled with sand by a blow operation, then the two flask sections compacted about the patterns 20 and 22 by a simultaneous squeeze operation, then the flask sections separated by a pattern draw or strip-out operation in order to release the match plate assembly 20 and its affixed patterns, then the match plate assembly 20 and its patterns removed from the working area of the machine by a pattern transfer operation under the control of a transfer mechanism 23, then the flask sections 16 and 18 with their contained compacted sand brought together during a mold assembly operation to unite the two formed mold sections and establish a completed sand mold, then the flask sections withdrawn or stripped from the assembled sand mold by a strip-out operation, then the sand mold removed from the working area of the machine by a mold-ejecting operation, and finally the match plate returned to its initial position within the working area and between the two flask sections preparatory to initiation of the next succeeding machine cycle. The operation of the machine is repetitive, each machine cycle serving to produce a complete composite sand mold including upper (cope) and lower (drag) mold sections which are closed upon each other to produce the desired mold cavity ready for a metal-pouring operation.

With the exception of the movement of the match plate assembly 20, the various machine movements which are outlined above are in-line vertical movements which take place along a vertical axis extending through the working area of the machine, this working area being designated by the reference letter W (see FIG. 2). The upper cope flask section 16 is capable of limited vertical movement within the working area W of the machine and under the control of a pair of hydraulically operable cope cylinders 24. This upper cope flask section normally remains in a lowered position during a major portion of the machine cycle, but near the end of the cycle and immediately prior to the mold pushout operation, it is caused to cluding a lower drag squeeze plate 28, a central lift plunger 30 for the squeeze plate, an outer tubular drag frame extension 32 in fixed and depending relation with the lower drag flask section 18, and an intermediate floating plunger 33 between the plunger 30 and the extension 32, together with associated cylinders and other hydraulic control mechanisms for actuating the parts or

elements

32, 30, and 33 in timed relationship during the machine cycle as also will be set forth in detail subsequently. The lower drag squeeze plate 28 operates within the lower drag flask section 18 and the upper cope flask section 16 also has associated therewith a fixed upper squeeze plate 34 which functions not only as a squeeze plate but also as an element of a composite or combined blow and squeeze plate assembly 36, the details of which will be made clear subsequently in connection with the description of FIG. 24 of the drawings.

During the clamping and blowing operations of the machine 10, the tubular control plunger 32, in combination or cooperation with the cope cylinders 24, maintains the cope and drag

flask sections

16 and 18, with the match plate assembly 20 and its supported

patterns

21 and 22 sandwiched between them, in

operative register with respective fixed positioned

sand magazines

38 and 40, the magazine 38 serving to introduce sand into the upper end of the upper cope flask section 16 through the combined blow and squeeze plate assembly 36, and the magazine 40 serving to introduce sand into the lower drag flask section 18 through one side of the latter. Sand is introduced into both

magazines

38 and 40 from a common sand hopper 42 (see FIGS. 1 and 2) through respective

sand distribution channels

44 and 46 by gravity feed. A shut-off gate mechanism 50 is interposed in the channel 44 between the common sand hopper 42 and the sand magazine 38, and a similar shut-off gate mechanism 52 is interposed in the channel 46 between the common sand hopper 42 and the sand magazine 40.

The sand in the

magazines

38 and 40 is introduced into the

flask sections

16 and 18, respectively, by the simultaneous ac tion of a pair of

agitator mechanisms

53 and 54 and a pair of blow valves 55 and 56, the agitator mechanisms serving to maintain the sand in the magazines in a state of suspension, while the blow valves function by means of respective pairs of distribution heads (see FIG. 1) and 61 (see FIG. 2) to aerate the magazines and cause the sand to be ejected therefrom and carried into the flask sections through blow slots in certain walls of the latter. The blow slot for introduction of sand into the lower drag flask section 18 is shown in FIGS. 1, 6 and 8 of the drawings and is designated by the reference numeral 57, while multiple slots 58 for introduction of sand into the upper cope flask section 16 are shown in FIG. 24, these latter slots being formed in the upper squeeze plate 34 of the combined blow and squeeze plate assembly 36.

The specific movements which are imparted to the flask sections 16 and I8 and the match plate assembly 20 and are involved in the production of a completed composite sand mold during one complete machine cycle will be described in detail when the nature of the invention has been more fully set forth. However, for the present it is deemed pertinent to state that after the draw and transfer operations have been completed and the lower drag squeeze plate 28 has moved upwardly to force the squeezed sand in the lower drag flask section 18 against the squeezed sand in the upper cope flask section 16 as schematically shown in FIG. 19, the two flask sections are shifted vertically in opposite directions, that is, away from one another in order completely to release the thus completed and assembled composite sand mold as shown in FIG. 26, after which two ejector plungers 62 (see FIGS. 1 and ill) which are associated with an ejector mechanism 63 push the completed mold from the working area W of the machine It) and onto a bottom board 66, the latter being carried on a discharge table 66. As shown in FIG. 13, the machine utilizes a vertical series or stack S of bottom boards 64 and they are slid one at a time into position on the discharge table 66 by a board feeder mechanism 70 which periodically operates, to remove the lowermost board from the stack S and push the same forwardly onto the discharge table 66 at an appropriate point in the machine cycle, preferably immediately before the mold-ejection operation. As shown in FIG. 13, the stack S of boards 64'- is disposed in a fixedly mounted boxlike support 65 at one side of the discharge table 66.

THE MACHINE FRAMEWORK Only such portions of the machine framework as are essential for supporting the aforementioned operative machine parts and assemblies have been disclosed herein. Among the disclosed framework portions 141 are various vertical supporting standards or posts, horizontal beams, inclined braces, platforms and the like, the arrangement being an appropriate one for supporting the cope and drag

sand magazines

36 and 40, the lift table 26, the ejector mechanism 63, the transfer mechanism 23, the discharge table 66, and the board feeder mechanism 70. The portions lld of the framework further serve to support various small brackets and the like to which specific reference will be made as the following description ensues. Many functional stationary portions of the framework have been omitted from the disclosure herein in the interests of clarity, the illustrated portions 14 being sufficient to establish a reaction support for all of the movable machine elements or parts that are associated with the machine. In this respect, the disclosures of FIGS. 1 and 2 are, to a certain ex tent, schematic in their representation.

THE UPPER COPE FLASK SECTION AND ITS OPERATING INSTRUMENTALITIES (The Cope Section Proper) Still referring to FIGS. I and 2, and particularly to FIGS. 8 and It, the upper cope flask section I6 is in the form of an open-ended, boxlike, generally rectangular structure having opposed front and rear walls hill and 82 and opposed side walls 64" and 66. The upper and lower ends of the upper cope flask section 16 are open. In the upper region of the upper cope flask section T6, the inside wall surfaces of the same are vertical as indicated at 66 in FIG. 24 for proper sealing cooperation with the marginal edges of the fixed upper squeeze plate 34 during the squeeze operation, as well as during the pushout operation when said upper cope flask section 16 moves upwardly with respect to the plate 34.

The lower open rectangular rim of the upper cope flask section I6 is adapted to seat upon the peripheral region of the match plate assembly 20 as shown in FIG. 9, this seating remaining effective both during the blow and squeeze operations, as well as during the clamp operation. The rectangular boxlike structure which constitutes the upper cope flask section 16, in combination with the upper squeeze plate 345 and the match plate assembly 26, defines an interior flask cavity which encompasses the upper pattern 2i.

In the upper region of the upper cope clasp section 16, two anchoring and guide brackets 96 (see FIGS. 2, 8 and 9) project laterally outwards from the

side walls

84 and 66 of said upper cope flask section and are provided with vertical holes 92 which register with and slidably receive fixed vertically extending alignment pins 94 (see FIGS. 2 and I'll) which are car ried by and depend from brackets 95 on the upper cope sand magazine 38. The pins 96 cooperate with the holes 92 for maintaining the upper cope flask section 16 and the sand magazine 38 in vertical alignment at all times.

In the lower region of the upper cope flask section l6, the side wall 66 is provided with a laterally projecting car 96 (see FIGS. ll, ti and M which fixedly supports a downwardly projecting guide rod 96. The latter, in turn, cooperates with a hole 166 in a similar laterally projecting ear MP2 on the lower drag flask section Iii, said rod 96 and car 1162 serving to align the two

flask sections

16 and 16 during the blow and squeeze operations. Similarly, the side wall 66 of the upper cope flask section 116 is provided with a laterally projecting car IM hav ing a hole 166 therethrough, such hole is designed for cooperation with an upstanding pin 1108 provided on a laterally extending ear llilt) on the lower drag flask section 16.

Referring now to FIGS. I, 2, t and 9, and particularly to FIG. 26, front and rear walls and 62 of the upper cope flask section I6, as well as the

side walls

64 and 66, are lined with a wear-resistant material I112, such walls thus being of dual thickness. These walls are perforated and each perforation has mounted therein a small cup-shaped sand screen unit lllltl (see FIGS. 7 and 7A), the bottom wall llll6 of which is formed with a series of narrow parallel slits llllfl, the latter being of such small width that during the blow operation air may escape through the upper cope flask section walls while sand remains confined within the interior of said flask section 116.

(The Cope Lift Mechanism) Normally, during a major portion of the machine cycle, the upper cope flask section assumes its lowered position as shown in FIG. 6!. However, during the squeeze operation as shown in FIG. 9 while the vertically movable lower drag squeeze plate compacts the sand in the two

flask sections

116 and 18 about the upper and lower patterns 2t and 22 and against the fixed upper squeeze plate 34, the upper cope flask section 116 rises a slight distance so that the laterally extending guide brackets 96 slide upwardly on the pins 94. During the pattern draw or strip-out operation, the aforementioned cope cylinders 24 function positively to raise the upper cope flask section l6 with respect to the composite sand mold M so as to break the bond between the sand and the various walls of the upper cope flask section 16, while at the same time the lower drag squeeze plate 28 becomes lowered to drop the mold M to the level of the ejection plungers 62 for subsequent ejection from the working area W of the machine 16 during the final pushout or mold ejection operation. Toward this end, the cope cylinders 26 are provided with vertically extending plungers I26 which have their lower ends secured to the aforementioned guide brackets 96 in the medial regions of the latter (see FIGS. 2 and Ill).

Til-IE LOWER DRAG FLASK SECTION As best shown in FIGS. I, 2, 6 and 9, the lower drag flask section I6 is in the form of a rectangular boxlike structure having an open upper rim and including front and rear walls I22 and 1126 and side walls I26 and I226. The aforementioned blow slot 57 is formed in the rear wall I22 and extends horizontally thereacross in the upper region thereof as shown in FIG. l and It. The upper rectangular rim of the lower drag flask section lift is designed for sealing engagement with the match plate assembly 26 during the blow and squeeze operations as shown in FIGS. 15 and I6 and as will be fully described subsequently. The four walls 1122, I26, 126 and 128 of the lower drag flask section 16 are perforated as shown in FIG. 6 in a manner similar to the perforations in the walls till, 62, 8d and 86 of the upper cope flask section 16 and each perforation has installed therein one of the aforementioned sand screen units llll l of FIG. 7 to prevent egress of sand from the lower drag flask section l8 during the blow operation. The lower drag flask section walls also are lined with wear-resistant material similar to the material 1112 on the inner surfaces of the

walls

86, 62, 8d and 86 ofthe upper cope flask section I6.

THE SQUEEZE PLATE ASSEMBLIES (The Upper Combined Squeeze and Blow Plate Assembly) As previously stated, the fixed upper cope squeeze plate 3 functions not only as an upper sand compacting member, but it also constitutes an element of the combined blow and squeeze plate assembly 36 by means of which sand in the cope magazine 38 is introduced into the interior of the upper cope flask section 16. This assembly 36 is shown in detail in FIG. 24 and consists of three parts, namely, a top plate 130, a bottom plate which comprises the squeeze plate 34, and an intermediate grid or spacer plate 132. The top plate 130 directly underlies the cope sand magazine 38 and is provided with a se ries of blow slots 134 therein and, accordingly, for convenience of description herein, it is regarded as constituting the blow plate proper. The blow slots 134 are in vertical register with sand discharge openings 136 in the spacer plate 132 and the slots 58 in the squeeze plate 34 The sand which leaves the magazine 38 passes through the blow slots 134, the discharge openings 136 in the spacer plate 132 and the slots 58 in the squeeze plate 34 in the order named The combined blow and squeeze plate assembly 36 is a fixed assembly and the marginal edges of the squeeze plate 34 of said assembly closely approach the four walls of the upper cope flask section 16 so that sand in such flask-section undergoing squeezing at the time the lower squeeze plate 26 moves upwardly will be subjected to substantially uniform pressure throughout its mass. Small sand screen units (not shown) like those which are mounted in the perforations in the walls of the flask sections are installed in the slots 58 in the squeeze plate 34. If desired, the underneath side of the squeeze plate 34 may be lined with high-impact, wear-resistant material although no disclosure thereof is made herein. The squeeze plate 34 is normally disposed within the upper confines of the upper cope flask section 16, but this plate and the upper cope flask section are capable of relative vertical displacement during the squeeze and terminal mold pushout operations as previously set forth.

(The Lower Squeeze Plate) The lower drag squeeze plate 28 is best illustrated in FIGS. 8, 9 and 23. It is of rectangular configuration, has an upper coextensive liner 142 of wear-resistant material, and is capable of vertical movement within the confines of the lower drag flask section 18 between the lower position wherein it is shown in FIG. 8 and the fully raised position wherein it is shown in FIGS. 9, 20 and 21, this latter position being assumed during the sand mold ejecting operation as will be described subsequently when the operation of the machine is explained in detail. During the squeeze operation as shown in FIG. 9, the lower drag squeeze plate 28 assumes an intermediate position wherein it is raised a distance which is determined by the compression reaction factor of the compacted sand within the cavities in the

flask sections

16 and 18.

THE MATCH PLATE ASSEMBLY AND ITS TRANSFER MECHANISM (The Pattern Plate Proper) The match plate assembly 20 comprises a pattern plate 150 (see FIG. 8) on which the upper and

lower patterns

21 and 22 are mounted, and a marginal pattern plate frame 152 which depends from the peripheral region of the pattern plate 150 and consists of front and rear frame bars 154 and 156 and side frame bars 158 and 160. Said match plate assembly is thus of inverted shallow tray-like design and the various frame bars are downwardly and outwardly inclined in conformity with the inclination of the lower regions of the various walls of the upper cope flask section 16. The lower rectangular rim of the tray-like match plate assembly 20 is designed for sealing engagement with the upper rectangular rim of the lower drag flask section 18 as shown in FIG. 9 during the blow and squeeze operations of the machine 10. When this sealing relationship is attained, the depending walls of the match plate assembly, i.e., the pattern plate frame 152, constitutes, in eflect, an upper extension of the lower drag flask section 18. Thus, during the blow operation of the machine, the lower drag cavity which is to be filled with sand from the magazine 40 is defined by the four frame bars of the pattern plate frame 152, the four walls of the lower drag flask section 18, the pattern plate and the lower drag squeeze plate 28. The frame bars 154, 156, 158 and 160 are provided with perforations (not shown) and such perforations are vented by means of screen units in a manner similar to the venting of the cope and drag

flask sections

16 and 18.

(The Match Plate Assembly Transfer Mechanism) As previously stated, the match plate assembly 20 is movable under the control of the transfer mechanism 23 in a horizontal plane between a retracted position wherein it lies outside the working area W of the machine and a projected position where it lies in the working area and assumes a position between the upper cope flask section 16 and the lower drag flask section preparatory to closing of these flask sections on-the match plate assembly 20 during the clamping operation of the machine 10. These extreme positions of the match plate are clearly illustrated in FIGS. 11 and 12. Shifting of the match plate assembly 20 is effected under the control of a match plate assembly supporting carriage which travels back and forth along a pair of parallel horizontally extending guide rods 172. The latter project forwardly from a reinforced reaction bracket 173 which is suitably mounted on and constitutes a part of the machine framework; The carriage 170 includes a pair of forwardly projecting, horizontally extending, parallel match plate assembly supporting bars 174 which constitute a forward extension of the carriage, the match plate assembly 20 resting loosely upon these supporting bars 174 and being adjustable thereon for levelling purposes as will be described presently. The carriage 170 of the .transfer mechanism 23 is movable between a retracted position wherein the supporting bars 174, together with the match plate assembly 20, project into the working area W of the machine as shown in FIG. 11, and a retracted position wherein these supporting bars and the match plate assembly 20 are withdrawn from such area as shown in FIG. 12.

Movement of the carriage 170 is effected under the control of a Scotch yoke drive mechanism embodying a crank arm 176, the outer end of which carries a roller 178 that travels in a vertical slot 180 in an upstanding track bar 182 on the carriage 170. The crank arm 176 is adapted to be oscillated or swung back and forth through an angle of 180 by means of a rotary hydraulic motor 184 which is mounted on a framework portion 14 (see FIGS. 11 and 12), the two horizontal positions of the arm 176 determining the two extreme positions of the carriage and consequently the match plate assembly 20.

The two parallel supporting bars 174 straddle the opposite sides of the pattern plate frame 152 and the forward corner regions of said pattern plate frame are provided with lateral ears 186 which threadedly receive therethrough vertically extending levelling screws 188, the lower ends of these screws resting upon the forward end regions of the supporting bars 174 of the carriage 170. The rear corner regions of the pattern plate frame 152 are provided with horizontally extending coupling ears 190 having formed therein vertical holes 192 which receive threaded upstanding posts 194 having levelling nuts 196 thereon, the posts 194 being mounted on a fixed bracket 197 on the central portion of the carriage 170. From the above description, it will be apparent that the match plate assembly 20 loosely rests upon the carriage 170, the front corners of the pattern plate frame 152 being adjustably supported at the forward end of the bars 174 and the rear corners of the pattern frame being adjustably supported on the central portion of the carriage by way of the nut-equipped upstanding posts 194.

The front support for the match plate assembly 2t) on the parallel supporting bars T74 is effective to carry the match plate assembly 2d forwardly across the working area W of the machine during projection of the bars forwardly into such working area. However, when the carriage ll'Tfl reaches its fully projected position as shown in FIGS. 1, d and ill, a pair of forwardly projecting cam ledges i193 adjacent to the front corners of the pattern plate frame 152 ride onto two rollers 2% which are carried on sleeve brackets 202, thus reinforcing the cantilever type of support which the carriage 170 other wise would be obliged to offer when the match plate assembly is fully projected into the working area W. The two sleeve brackets 202 are vertically adjustable on certain vertical portions 114 of the machine framework by means of cooperating adjusting screw devices 2194 (see FIGS. ill and 114).

THE HYDRAULlCALLY-OPERABLE LIFT TABLE The hydraulically-operable lift table as which, as previously stated, functions variously to impart vertical movements to the lower squeeze plate 23 and the lower drag flask section Mi is illustrated in detail in H65. 22 and 23. The upper end of the aforementioned central lift plunger 30 is fixedly secured by bolts 26% to the lower drag squeeze plate 28 and is surrounded by a fixed vertically extending cylinder body 210 within which the plunger 36) operates. The lower end of the cylinder body 2W embodies a bottom closure wall 2ll2 and is provided with an oil inlet port 21%. The lower end of the cylinder body 210 is fixedly secured to a base supporting structure 2llb which constitutes a fixed portion of the machine framework as shown in FIGS. l and 2. The previously mentioned tubular drag frame extension 32 constitutes the outermost tubular member of the lift table 26 and its upper end is connected to the lower drag flask section lid by way of bolts 2T8. On opposite sides of the extension 32, a series of radially extending, spaced apart gusset webs 2T5 lends support to the extension. The previously mentioned intermediate floating plunger 33 immediately surrounds the cylinder body 2M) and has its upper rim secured to the lower squeeze plate 2d by bolts 22b and this plunger is interposed between the cylinder body 2M and the tubular drag frame extension 32 and functions to control the movements of the lower drag flask section 113 with respect to the lower drag squeeze plate 28. Stated otherwise, whereas the central lift plunger 3ft functions to control the absolute movements of the lower drag squeeze plate 23, the intermediate floating plunger 33 functions to control its relative movements and this latter plunger will hereinafter be referred to as the drag control plunger 33.

Suitable seal assemblies

224 and 226 are bolted in position to seal the upper and lower ends of the annular chamber 223 which exists between the drag control plunger 33 and the tubular drag frame extension 32 while a piston ring and groove arrangement 230 is provided on the outside of the drag control plunger 33 and arranged to engage the inner periphery of the tubular extension 32.

A vertical guide bar or key 231 (see FIGS. 22 and 23) is secured at its lower end by bolts 233 to the base portion of the cylinder body 2M) and is straddled by a pair of keeper plates 235, the key and keeper plates serving to prevent relative turning movement between the lift table parts. Two vertically extending suspension links 237 are pivoted at their upper ends to the keeper gates on opposite sides of the key 2311 and carry rollers 239 at their lower ends, the rollers bearing against the opposite side edges of the key. Adjusting screws 24ll regulate the pressure of the rollers against the key and also provide a means for effecting slight rotational adjustment of the angular position ofthe tubular drag frame extension 32 to the end that small angular displacements of the lower flask section l8 may be effected.

An upper oil port 232 is formed in the tubular drag frame extension 32 and leads to the annular chamber 228 while a similar lower oil port 234 also is formed in this extension, the two ports being disposed on the opposite sides of the piston ring and groove arrangement 230. The

ports

232 and 234 are connected to flexible oil supply conduits 23b and 238, respectively.

The specific movements of the central lift plunger 30, the drag control plunger 33 and the tubular drag frame extension 32 which take place during the machine cycle will be described in detail when the operation of the sand mold making machine llll is set forth subsequently. However, for the present, it is deemed pertinent to state that the admission of oil to the port 224 will serve forcibly to slide the central lift plunger 33 upwardly, thus positively forcing the lower drag squeeze plate 28 upwardly. Such upward movement of the lower drag squeeze plate will pull the drag control plunger 33 upwardly, thereby imparting upward movement to the tubular drag frame extension 32, and consequently, the lower drag flask section 113 by reason of the entrapped solid column of oil Within the annular chamber 228 above the piston ring and groove arrangement 234) through the port 234 will force the tubular drag frame extension 32 downwardly with respect to the drag control plunger 33, thus effecting relative movement between the lower drag squeeze plate 23 and the lower drag flask section lid. This relative motion applies an upward component of force to the lower drag squeeze plate 23 and a downward component of force to the lower drag flask section 118. Oil which is introduced at line pressure into the annular chamber 223 through the port 232 will likewise effect relative movement between the lower drag squeeze plate 23 and lower drag flask section lid but the aforementioned components of force will be reversed. It will be understood when the description of the operation of the machine is set forth more in detail hereafter that when either

port

232 or 234 is employed as an inlet port to admit oil to the annular chamber 225, the other port will function as a vent or bleeder port to allow oil to escape from annular chamber.

THE SAND MAGAZINES The cope sand magazine 33 and the drag sand magazine 40 are similar in their construction, the only difference therebetween residing in their placement or position with respect to the flask sections which they serve and in the fact that the cope sand magazine 33, during the blow operation, feeds sand downwardly into the upper end of the upper cope flask section in through the aforementioned multiple blow slots 52 in the fixed upper cope squeeze plate 34 while the drag sand magazine 40 feed its sand laterally into the lower drag flask section 18 through the aforementioned single blow slot 57' (see HUS. l and ii) in the rear wall T24 of the lower drag flask section lift. Therefore, it is believed that a description of the drag flask magazine 4t) which is more clearly illustrated in the drawings will suffice to a large extent for both sand magazines.

(The Drag Flask Sand Magazine) The details of the drag flask sand magazine 40 and its associated operative instrumentalities are best illustrated in N68. 2, 5 and s of the drawings. This magazine 40 is generally of cylindrical design and embodies a continuous cylindrical side wall 25d on which the pair of the aforementioned air distribution heads til is mounted. The two air distribution heads till are identical and each head defines a duct 252 (see FlG. 5) across which there extends a dual thickness air distribution screen or blow plate 254. The duct 252 communicates with an air inlet opening 256 in the cylindrical. side wall 250. An air chamber 257 on the side of the blow plate 254 that is remote from the inlet opening 256 communicates through a port 258 with a wind box 26% to which air is supplied by way of a conduit 262 which leads to the associated blow valve 56. As will be set forth presently, the sand which is introduced into the drag flask magazine 43 through the open upper end thereof from the associated shut-off gate mechanism 52 is aerated during the blow operation of the machine ill by the action of the air that issues from the blow valve 56 and passes through the air distribution blow plate 254. At the same time, this aerated sand is caused to be agitated by the action of the aforementioned agitator mechanism 54 and forcibly ejected from the magazine 40 through a blow opening 264 at the outer ill.

end of a blow extension 266. The latter has its upper inlet end in communication with the interior of the magazine 40 and is arranged so that its lower discharge end registers with the aforementioned blow opening 57 in the lower drag flask section 18 during the blow operation.

(The Agitator Mechanism For The Sand Magazine 40) The agitator mechanism 54 (see FIG. for the drag sand magazine 40 is identical with the agitator mechanism 53 for the cope sand magazine 38 so that a description of the mechanism 54 will suffice for the mechanism 53. This agitator mechanism 54 includes a motor 270 which is suitably mounted on certain portions 14 of the machine framework and has an upwardly extending drive shaft 272 which projects into the interior of the drag flask sand magazine 40 and carries a spiderlike agitator head 274 (see FIG. 5). The motor 270 is preferably of the fluid-actuated oscillatory vane type and, accordingly, it is provided with a pair of fluid ports 275 for the selective admission of motive fluid,

THE SHUT-OFF GATE MECHANISMS The two shut-off gate mechanisms 50 and 52 (see FIG. 2)

are substantially identical, the mechanism 50 being supported upon and overlying the cope flask sand magazine 38 and the mechanism 52 similarly being supported upon and overlying and, in addition, a bottom opening 312 which defines a sand outlet and is in communication with the upper end of the cope flask sand magazine 38. The front and

rear walls

302 and 304 are provided with relatively large circular openings 313.

Rotatably disposed within the internal chamber in the housing 300 is a frustoconical plug 314 having formed therein a diametrically extending bore 316 which, when the plug is in one angular position, is out of register with the two

openings

310 and 312, and when the plug is in another angular position, registers with both openings. The shut-off gate mechanism 50 is interposed between the downwardly extending and distribution channel 44 of the hopper 42 (see FIG. 2) and the cope flask sandmagazine 38, and the upper region of the housing 300 of said shut-off gate mechanism is provided with an upwardly extending neck portion 318 which establishes communication between the sand distribution channel 44 of the sand hopper 42 and the sand inlet opening 310. Similarly, the lower region of the housing 300 is provided with a depending neck portion 320 which establishes communication between the sand outlet opening 312 of the shut-off gate mechanism 50 and the upper end ofthe cope flask sand magazine 38.

Hydraulic means are provided for rotating the frustoconical plug 314 of the shut-off gate mechanism 50 back and forth between the off" position wherein it is shown in FIG. 4 and the on position wherein it is shown in FIG. 4A. Accordingly, a piston and cylinder assembly 321 (see FIG. 3) is pivotally mounted on a fixed reaction bracket 322 and includes a piston rod 323 which has its outer end pivoted as at 324 to an eccentric point on the front circular face of the frustoconical plug 314 which is exposed through the large-sized opening 313 in the front wall 302 of the housing 300. When the piston rod 323 is in its projected position as shown in full lines in FIG. 3, the diametric bore 316 in the plug 314 is out of register with the top and bottom openings 308 and 310; and when the piston rod 323 is retracted'as shown in dotted lines in this view, the bore 316 is in register with both openings.

In order to prevent air backup during the blow operation, means are provided for positively sealing the plug 314 to the frustoconical peripheral wall 306 of the housing 300, thereby effectively sealing both openings therein. Accordingly, the frustoconical plug 314 is capable of limitedaxial shifting movement within the housing 300, and a pair of

hydraulic cylinders

325 and 326 on spiderlike brackets 328 are disposed in alignment on opposite sides of said housing. The cylinder 325 is provided with a plunger 330 which is secured to the small end face of the plug 314 while the cylinder 326 is provided with a plunger 332 which is secured to the large end face of the plug. By selectively applying fluid under pressure to either cylinder while bleeding the other cylinder, the frustoconical plug 314 may be effectively shifted into and out of sealing engagement with the frustoconical peripheral wall 306 of the housing 300 of the shut-off gate mechanism 50. During the blow operation, the cylinder 326 is supplied with fluid under pressure to effect the aforementioned seal. In order to effect rotational shifting movements of the plug in either direction, the cylinder 325 is supplied with fluid under pressure in order to relieve friction between the plug 314 and its surrounding peripheral wall 306.

v THE SAND MOLD EJECTOR MECHANISM The previously mentioned sand mold ejector mechanism 63 is shown in detail in FIGS. 11 and 12 of the drawings. It is mounted on the same reaction bracket 173 that carries the match plate transfer mechanism 23. This ejector mechanism 63 embodies a pair of parallel elongated horizontally disposed cylinders 400 from which the aforementioned ejector plungers 62 project. The two cylinders 400 are secured at their rear ends to the bracket 173. The plungers 62 carry at the inner ends thereof pistons 402 which are slidable within the cylinders 400,

and'fluid ports

404 and 406 are provided in the cylinders on opposite sides of the pistons 402. When fluid under pressure is supplied to the ports 404, the plungers 62 are projected from the cylinders as shown in dotted lines in FIG. 11. When pressure fluid is supplied to the ports 406, the plungers 62 become retracted, this being the nonnal position of the plungers as shown in FIG. 14 which represents the start position of the machine. As previously stated, projection of the plungers 62 from the cylinders 400 serves to impel the last completed sand mold M laterally from the working area W of the machine and deposit the same on a bottom board 64 which has been placed upon the discharge table 66 by the board feeder mechanism 70 of FIG. 7.

(The Sand Mold Bridge) In order to allow for upward movement of the various flask section parts during the operation of the machine 10, it is necessary that the discharge table be spaced a slight distance away from the working area W of the machine as shown in FIGS. 14 through 21. Accordingly, during the lateral discharge of the sand mold M from the working area W under the influence of the plungers 62, it is necessary to provide a continuous support for the sand mold as it slides from the lower squeeze plate 28 onto the discharge table 66. Accordingly, as best illustrated in FIGS. 11 and 12, a bridge member 420 is pivoted to a bracket 422 which is carried by a particular portion 14 of the machine framework and has mounted thereon a small roller 424. The latter is normally positioned in the path of movement of a vertically disposed, spring-biased, bridge member, displacement rack 426 which has its upper end region fixedly secured to the lower drag flask section 18 as shown in FIGS. 18, 19 and 20. Normally, the bridge member 420 assumes a horizontal position and lies in the general plane of the bottom board 64 on the discharge table 66 with its distal edge resting upon the upper rim of the lower drag flask section 18 as shown in FIG. 11. However, as the lower drag flask section rises to commence the clamp operation, for example, the upper end of the rack 426 engages the roller 424 and thus upwardly displaces the bridge member I20 as shown in FIG. I2, the bridge member remaining in its displaced position until such time as the lower drag flask section 18 is restored to its lowermost position, at which time the bridge member automatically returns to its horizontal positron.

(The Bottom Board Feeder Mechanism) The bottom board feeder mechanism "70 which, as aforesaid, withdraws the lowermost bottom board 64 from the stack of bottom boards on the support 65 and deposits the same onto the discharge table 66 embodies a horizontally disposed cylinder I23 (see FIG. I3) having a slidably mounted plunger 636 which has pivoted to its outer end an upstanding pawl .432. The latter is biased by a spring 636 to a position wherein its distal end projects slightly above the level of the support 65 to the end that when the plunger T36 is projected from the cylinder I28 it engages the rear edge of the lowermost bottom board 64 and slides the same from beneath the stack 5 and deposits the same onto the discharge table 66. During the return stroke of the plunger 336, the pawl 632 is deflected by the underneath side of the next succeeding bottom board in the stack S, and when the plunger is completely retracted, the pawl assumes a position rearwardly of the rear edge of the latter board. The operation of the plunger 33i.) in withdrawing bottom boards from the stack is repetitive, one stroke of the plunger being effecting during each machine cycle.

OPERATION OF THE MACHINE A schematic representation of the machine is portrayed in FIGS. M to Jill, inclusive. In these views, substantially all of the machine framework has been omitted in the interests of clarity, as has also the sand magazines 38 and All), the shut-off

gate mechanisms

50 and 52, and the sand hopper i2. Additionally, in some of these views, certain elements which bear a relation to the function undergoing description are disclosed, while in other views such elements are omitted. These views will be described partly with reference to FIG. 23 which illustrates the operation of the lift table 26 and the manner in which it controls the lower drag flask section movements as well as the lower squeeze plate movements.

(The Start Position) The start position of the machine It) at the commencement of the machine cycle is illustrated in FIG. M. The supply of oil under pressure to the various ports 21 i, 232 and 234 (see FIG. 23) is cut off so that the lower squeeze plate 28 and the lower drag flask section III are in the lowermost positions of which they are capable of assuming. The cope cylinders 24 maintain the upper cope flask section I6 in its lowermost position, while the cylinders 4160 (see FIGS. II and I2) of the ejector mechanism 63 maintain the ejector plungers 62 retracted. The vane-type hydraulic motor I66 (see FIGS. II and III) maintains the match plate assembly projected into the working area W of the machine between the vertically spaced apart cope and drag flask sections 116 and Id with the forward or distal end thereof resting on the frame-supported roller ZIIII.

(The Clamping Operation) To effect the clamping operation which is illustrated in FIG. 15 of the drawings, oil under pressure is supplied simultaneously to the upper port 232 (see FIG. 2.3) and also the inlet port 2M in the lower end of the cylinder body ZIII. The oil entering the port 232 effects relative movement between the drag frame extension 32 and the drag control plunger 33, thus raising the lower drag flask section I3 with respect to the central lift plunger 30. However, at this time, the application of oil under pressure to the port 2M causes the central lift plunger 36 to be raised. The net effect of this is to raise the entire lift table, i.c., the lower drag flask section 118 and its squeeze plate Isis. 23, bodily until the upper rim of the lower drag flask section engages the pattern plate frame I32 and raises the match plate assembly 20, thus establishing a flask cavity beneath the pattern plate I36. Thereafter, the match plate assembly 20, which is a free floating assembly, is lifted from the frame-supported roller BIIII and the supporting bars I74l (see FIG. II) and is carried upwardly by the rising lower drag flask section I6 until the pattern plate I56 engages the lower open rim of the upper cope flask section I6, thus establishing a flask cavity above the pattern plate 1156. Oil under pressure is maintained in the cope cylinders 24 so that the lower cope flask section I6 will not yield upwards. At this point, the various alignment pins and ears on the flask section parts maintain the sections I6 and III in accurate vertical register as previously described.

(The Blow Operation) After the two flask sections I6 and I3 have been clamped against the match plate assembly 2tll as described above in connection with FIG. I3, the blow operation is initiated, such operation serving to fill both flask cavities with sand. The two shut-off gate mechanisms 50 and 52 (see FIGS. I and 3) are actuated by supplying fluid under pressure to the piston and cylinder assemblies III/II thereof, thus shifting the position of the plugs 3M so that the bores 3I6 therein establish communication between the overlying sand hopper I2 and the

underlying sand magazines

46 and 42, respectively. Sand then flows by gravity from each gate mechanism as shown in FIG. IA and as previously described.

During this sand blow operation, air under pressure is sup plied by the blow valve 55 (see FIG. I) to the distribution heads 66 of the cope sand magazine 36 and is also supplied by the blow valve 536 (see FIG. 2) to the distribution heads 6I of the drag sand magazine 4M]. As previously set forth in connection with the description of the

sand magazines

38 and 40, the agitator motors 270 (see FIG. 2) for the

agitator mechanisms

53 and 54 are energized so that the sand which enters the sand magazines 3% and at) through the distribution screens or blow plates (see FIG. 5) is both aerated and agitated. It is to be noted at this point that FIG. I5 is illustrative of the position of the flask sections I6 and III and the match plate assembly 26 during both the clamp and the blow operation. After the blow operation has been completed, the flask cavities are filled with sand as shown in this view.

(The Squeeze Operation) After the blow operation has been completed as heretofore pointed out and the cavities in the two flask sections I6 and III have been filled with sand, oil under pressure is supplied to the port 2M (see FIG. 2.3) and oil pressure at the port 232 is relieved. This has the effect of further raising the central lift plunger 30 and forcing the lower squeeze plate 28 upwardly against the sand in the lower flask cavity as shown in FIG. I6 and applying upward pressure to the pattern plate I50. In order to transfer the pressure which is thus established in the lower flask cavity to the upper flask cavity, fluid pressure in the two cope cylinders 24 is relieved and the upper flask section is forced upwardly by the upward thrust of the pattern plate I56 to the end that the fixed upper squeeze plate 34 enters the latter flask section with the net result that the entire mass of sand which straddles the pattern plate ISO is com pressed between the two

squeeze piates

28 and 34 and about the patterns ZZZ. and ZI on the pattern plate 150. This squeeze operation establishes a completed upper sand mold section MU in the upper cope flask section I6 and a completed lower mold section ML in the lower drag flask section I8.

(The Pattern Draw Operation) To effect the pattern draw operation after completion of the aforementioned squeeze operation, the oil under pressure at the port 2M (see FIG. 23) in the lower portion of the cylindri cal body 2M is relieved in order to allow the central lift plunger 36, and consequently, the entire match plate assembly 20 and the lower squeeze plate 28 to move downwards as a unit. During the descent of the match plate assembly and the lower squeeze plate, the forward end of the match plate assembly comes to rest upon the frame-supported roller 200 as shown in FIGS. 11 and 17, and the match plate assembly is returned to the supporting bars 174 of the match plate transfer mechanism 23 (see FIG. 11) so that further descent thereof is prevented. The continued downward movement of the lower drag flask section 18 and its lower squeeze plate 28 carries the lower sand mold section ML downwardly until the various parts assume the positions in which they are shown in FIG. 17 with the upper sand mold section MU still retained in the upper cope flask section 16 and the match plate assembly in its normal medial suspended position between the two separated flask sections. The upper and

lower patterns

21 and 22 are thus freed from their respective sand compacted or squeezed mold sections.

(Pattern Plate Retraction) In order to withdraw the match plate assembly 20 from the working area W of the machine and thus provide clearance for the uniting of the two compacted sand mold sections MU and ML, the hydraulic vane-type motor 184 (see FIG. 11) is actuated so as to swing the crank arm 176 throughout an angle or are of 180 and retract the transfer carriage 170 as previously described so that the parts assume the positions in which they are shown in FIG. 18 with the match plate assembly 20 in an out-of-the-way position.

(The Mold Closing Operation) With the match plate assembly 20 and its associated

patterns

21 and 22 in the out-of-the-way position wherein they are illustrated in FIG. 18, mold-closing operations to bring the upper and lower compacted sand mold sections MU and ML together are resorted to by supplying oil under pressure to the aforementioned port 214 (see FIG. 23), thus causing the central lift plunger 30 to move upwardly and carry the entire assembly of the lower squeeze plate 28, the lower drag flask section 18 and the lower sand mold section ML bodily upwards as a unit until the upper face of said lower sand mold section engages the underneath face of the upper sand mold section MU which still is retained by its adhesion to the walls of the upper cope flask section 16. The position of the parts at this time is illustrated in FIG. 19.

(The Mold Striping Operation) The mold stripping operation which sometimes is referred to as the push-out operation, is illustrated in FIG. 20. To effect this mold stripping operation, the oil under pressure at the port 214 (see FIG. 23) is relieved so as to lower the drag flask section 18, the lower squeeze plate 28 and the sand mold section ML resting thereon bodily as a unit and subsequently relieving the pressure at the port 234 to lower the lower drag flask section 18 with respect to the lower squeeze plate 28 so that the latter becomes elevated with respect to the lower drag flask section 18 and projects a small distance above the level of the upper rim of this flask section as shown in FIG. 20, the lower mold section ML resting on the lower squeeze plate 28 preparatory to being pushed over the upper rim of the lower drag flask section 18 and onto the bottom board 64 which has been deposited on the discharge table 66.

During this mold stripping operation, oil under pressure is supplied to the upper cope cylinders 24 so as to raise the upper cope flask section 16 with respect to the fixed upper squeeze plate 34 and thus strip the upper mold section MU from the walls of the upper cope flask section 16 to the end that this latter mold section also descends with the lower mold section ML.

It is to be noted at this point that during the descent of the lower drag flask section 18 as described in connection with the mold stripping operation, the upper end of the bridge displacement rack 426 releases the roller 424 so that the bridge The functioning of the mold ejecting mechanism 63 has been fully set forth previously and need not again be described at this point. However, it is to be noted that in connection with the disclosure of FIG. 21 which represents the mold ejection position of the various machine parts, the match plate assembly 20 is shown as being in its retracted position. Whether the match plate assembly be retracted or advanced and projected into the working area W of the machine, it nevertheless remains elevated on the parallel supporting bars 174 of the match plate supporting carriage and, therefore, offers no interference to the operation of the ejector plungers 62. The particular point in the machine cycle at which the ejector plungers 62 are caused to become projected from the cylinders 400 for mold discharge purposes is not critical, and purely for illustrative purposes herein, the match plate assembly 20 is stated to remain retracted until after the plungers 62 have performed their operative sand mold ejecting stroke. To restore the machine parts to the start position of FIG. 14, it will be understood that the transfer mechanism 23 of FIG. 11 will be actuated to shift the match plate assembly 20 back into the working area W of the machine.

As is customary in the present art, the upper cope flask section 16 is provided with the usual telescopic or other sprue pin assembly 450 (see FIG. 20) which leaves a pouring sprue passage 452 (see FIG. 21) in the upper mold section MU.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification since various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention.

Having thus describedthe invention what we claim as new and desire to secure by letters patent is: g

1. In a machine for simultaneously producing cope and drag sand mold sections, in combination, a framework establishing a working area, a lift table, a lower drag flask section and an upper cope flask section disposed in said working area in spaced apart vertical alignment and in the order named, said lower drag flask section having a side wall provided with a blow opening therethrough, a match plate mounted for lateral shifting movement between an advanced position wherein it is projected into said working area between the two flask sections and a retracted position wherein it is remote from the working area, said match plate also being capable of limited vertical free floating shifting movement, a fixed upper squeeze plate operable in the upper region of said upper flask section, said squeeze plate being provided with a multiplicity of blow openings therethrough, a lower squeeze plate operable in the lower region of the lower drag flask section, a plurality of circumferentially spaced cylinder and plunger assemblies for moving said upper cope flask section vertically, an hydraulically operable lift table for selectively moving said lower squeeze plate and said lower drag flask section vertically, said lift table including a central cylinder body, a lift plunger slidable vertically within said cylinder body and connected to said lower squeeze plate, an outer cylindrical plunger connected to said lower drag flask section, and an intermediate cylindrical floating plunger connected to said lower squeeze plate and interposed between the outer plunger and the central cylinder body, means for selectively supplying fluid to said lift table to provide a first stage of operation wherein the lower drag flask section and the lower squeeze plate move upwardly in unison so that the latter flask section engages the match plate and defines a lower flask cavity and lifts the match plate upwardly and into engagement with the upper cope flask section and defines an upper flask cavity, a second stage of operationsand in the upper flask cavity between the match plate and the fixed upper squeeze plate to produce an upper sand mold section, a third stage of operation wherein the lower drag flask and the lower squeeze plate move downwards in unison and restore the flask sections and the match plate to their spaced apart relationship, a fourth stage of operation wherein the lower squeeze plate and the lower drag flask section move upwardly in unison to bring the lower sand mold into engagement with the upper sand mold section, and a fifth stage of operation wherein the upper cope flask section alone moves upwardly with respect to the fixed upper squeeze plate to release the upper sand mold section and the lower drag flask section and the lower drag flask section and the lower squeeze plate move downwardly in unison to lower the contiguous upper and lower sand molds to a region of discharge, a first sand magazine effective between the first and second stages for introducing sand into said upper flask cavity through said multiplicity of openings in the upper squeeze plate, a second sand magazine likewise effective between the first and second stages for introducing sand into said lower flask cavity through the blow opening in the side wall of said lower drag flask section, and means effective between the third and fourth stages for removing said match plate from said working area.

2. In a machine for simultaneously producing cope and drag sand mold sections, the combination set forth in claim 1 and including, additionally, a sand hopper disposed above the level of said cope and drag magazines and having separate sand distribution channels leading to the latter.

3. ln a machine for simultaneously producing cope and drag sand mold sections, the combination set forth in claim 2 and including, additionally, a shut-off gate mechanism interposed in each distribution channel.

4. In a machine for simultaneously producing cope and drag sand mold sections, the combination set forth in claim 3,

wherein each shut-off gate comprises a gate housing mounted on said framework and defining an internal frustoconical chamber having an open upper end in communication with said hopper and an open lower end in communication with said cope flask section, and a frustoconical plug fitting snugly within said chamber and rotatable therein, said plug being provided with a diametrically extending bore therethrough, said plug being movable between a first position wherein said bore establishes communication between said open upper and lower ends of the housing and a second position wherein said open ends of the housing are out of communication with each other, and an hydraulic piston and cylinder assembly pivoted to the framework and to an eccentric point on said plug for actuating the latter.

5. In a machine for simultaneously producing cope and drag sand mold sections, the combination set forth in claim 1 and including, additionally, a discharge table positioned alongside said working area, an hydraulically operable cylinder and plunger assembly positioned adjacent to said working area and including a plunger engageable with the lower sand mold section when said lower squeeze plate is in its lowered position for sliding the contiguous mold sections laterally from said lower squeeze plate and depositing the same on said discharge table, and a bridge member pivoted tosaid framework for swinging movement about a horizontal axis between a lowered horizontal position wherein it bridges the distance between the lower squeeze plate and the discharge table and a raised substantially vertical position, and a displacement rack mounted on the lower flask section and movable bodily therewith and engageable with said bridge member for moving the latter from its lowered position to its raised position during upward movement of the lower flask section.

Claims

1. In a machine for simultaneously producing cope and drag sand mold sections, in combination, a framework establishing a working area, a lift table, a lower drag flask section and an upper cope flask section disposed in said working area in spaced apart vertical alignment and in the order named, said lower drag flask section having a side wall provided with a blow opening therethrough, a match plate mounted for lateral shifting movement between an advanced position wherein it is projected into said working area between the two flask sections and a retracted position wherein it is remote from the working area, said match plate also being capable of limited vertical free floating shifting movement, a fixed upper squeeze plate operable in the upper region of said upper flask section, said squeeze plate being provided with a multiplicity of blow openings therethrough, a lower squeeze plate operable in the lower region of the lower drag flask section, a plurality of circumferentially spaced cylinder and plunger assemblies for moving said upper cope flask section vertically, an hydraulically operable lift table for selectively moving said lower squeeze plate and said lower drag flask section vertically, said lift table including a central cylinder body, a lift plunger slidable vertically within said cylinder body and connected to said lower squeeze plate, an outer cylindrical plunger connected to said lower drag flask section, and an intermediate cylindrical floating plunger connected to said lower squeeze plate and interposed between the outer plunger and the central cylinder body, means for selectively supplying fluid to said lift table to provide a first stage of operation wherein the lower drag flask section and the lower squeeze plate move upwardly in unison so that the latter flask section engages the match plate and defines a lower flask cavity and lifts the match plate upwardly and into engagement with the upper cope flask section and defines an upper flask cavity, a second stage of operation wherein the lower squeeze plate alone moves upwardly and compresses sand in the lower flask cavity against the match plate to produce a lower sand mold section and compresses sand in the upper flask cavity between the match plate and the fixed upper squeeze plate to produce an upper sand mold section, a third stage of operation wherein the lower drag flask and the lower squeeze plate move downwards in unison and restore the flask sections and the match plate to their spaced apart relationship, a fourth stage of operation wherein the lower squeeze plate and the lower drag flask section move upwardly in unison to bring the lower sand mold into engagement with the upper sand mold section, and a fifth stage of operation wherein the upper cope flask section alone moves upwardly with respect to the fixed upper squeeze plate to release the upper sand mold section and the lower drag flask section and the lower drag flask section and the lower squeeze plate move downwardly in unison to lower the contiguous upper and lower sand molds to a region of discharge, a first sand magazine effective between the first and second stages for introducing sand into said upper flask cavity through said multiplicity of openings in the upper squeeze plate, a second sand magazine likewise effective between the first and second stages for introducing sand into said lower flask cavity through the blow opening in the side wall of said lower drag flask section, and means effective between the third and fourth stages for removing said match plate from said working area.

3. In a machine for simultaneously producing cope and drag sand mold sections, the combination sEt forth in claim 2 and including, additionally, a shut-off gate mechanism interposed in each distribution channel.

4. In a machine for simultaneously producing cope and drag sand mold sections, the combination set forth in claim 3, wherein each shut-off gate comprises a gate housing mounted on said framework and defining an internal frusto-conical chamber having an open upper end in communication with said hopper and an open lower end in communication with said cope flask section, and a frusto-conical plug fitting snugly within said chamber and rotatable therein, said plug being provided with a diametrically extending bore therethrough, said plug being movable between a first position wherein said bore establishes communication between said open upper and lower ends of the housing and a second position wherein said open ends of the housing are out of communication with each other, and an hydraulic piston and cylinder assembly pivoted to the framework and to an eccentric point on said plug for actuating the latter.

5. In a machine for simultaneously producing cope and drag sand mold sections, the combination set forth in claim 1 and including, additionally, a discharge table positioned alongside said working area, an hydraulically operable cylinder and plunger assembly positioned adjacent to said working area and including a plunger engageable with the lower sand mold section when said lower squeeze plate is in its lowered position for sliding the contiguous mold sections laterally from said lower squeeze plate and depositing the same on said discharge table, and a bridge member pivoted to said framework for swinging movement about a horizontal axis between a lowered horizontal position wherein it bridges the distance between the lower squeeze plate and the discharge table and a raised substantially vertical position, and a displacement rack mounted on the lower flask section and movable bodily therewith and engageable with said bridge member for moving the latter from its lowered position to its raised position during upward movement of the lower flask section.