US2877522A - Mold blowing apparatus - Google Patents

Description

March 17, 1959 H. J. B. HERBRUGGEN I 2,877,522

v MOLD BLowING APPARATUS Filed April 14, 1955 GvSheets-Sheet 1 March 17, 1959 H. J. B. HERBRUGGEN 2,877,522

MOLD BLOWING APPARATUS Filed April 14, 1955 6 Sheets-Sheet 2 INVENTOR.

,Morne/s March 17, l959- H. J. B. HERBRUGGEN 2,877,522

MOLD BLOWING APPARATUS Filed April 14, 1955 6 Sheets-Sheet 3 March 17, 1959 H. .J. B; HERBRUGGEN Mom BLowrNG APPARATUS 6 Sheets-Sheet 5 Filed April 14. 1955 INVENToR.

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United States Patent() MLD BLOWING APPARATUS Application April 14, 1955, Serial No. 501,287 4 Claims. (Cl. 22-36) This invention relates to the art of making sand molds, cores and the like and more particularly relates to improvements in apparatus for forming sand molds and cores by blowing sand into an enclosed cavity.

The improvements of this invention are particularly adapted for use in a sand blowing apparatus of the type in which sand is discharged from a chamber by means of an air stream and into a mold cavity formed by the ask, a top plate and a bottom pattern plate until the cavity is completely filled with sand. In simple molding, the drag and cope portions of the mold are usually formed independently in the apparatus which includes an arrangement for compacting the sand in each ask por tion so that the completed mold or core will resist deformation under pressure by the poured metal.

A principal object of this invention relates to the pro-I j l tern c'arrier and lift table assembly; and

2,877,522 Patented Mar. 17, 1959 umn illustrating the movable support for the spacer memspaced arms like 19 ber;

` Fig. 5 is a partial vertical section illustrating the position of the operative members in the flask receiving area prior to clamping;

Fig. 6 is a partial vertical section illustrating the position of the operative members in the ask receiving area during the sand blowing operation;

- Fig.Y 7 is a partial front elevation illustrating the pat- Fig. 8 is a vertical section illustrating the position of the operative members in the flask receiving area after removal of the spacer member and prior to compacting.

Referring now more particularly to Fig. 1 of -the drawings, there is shown a sand blowing apparatus for making molds or cores and embodying an upright frame having a base 10 supporting spacedv vertical columns 11 and 12 which are connected together at the top by a cross head 14. A sand discharge chamber 15 having a removable blow plate assembly 16 is pivotally supported by which are swingable about the column 12 to position the chamber 15 under a sand hopper 20 external to the frame. The base 10 also supports spaced flask rails 22 and 23 for receiving a cope or drag g ask in' aligned position beneath the sand chamber 15.

" Although not shown,

dling and increases production eiciency by permitting the pattern to be changed on one portion of the `carrier while another mold or core is being formed on another part of the carrier.

Another principal object'of this invention relates-to'a simplification in the apparatus for compacting sand in the flask or core box.

Briefly, in accordance with this invention a sand discharge chamber is operably supported on a frame in surmounting spaced relation over a flask lift table to define a flask receiving area therebetween. The frame also supports a movable multiple pattern carrier for presenting a selected pattern onto the lift table while removing another pattern therefrom. The mold or core is formed by discharging sand from the chamber into the mold cavity formed when the lift table clamps the flask against the discharge portion of the chamber. A spacer member is also movably supported on the frame for insertion between the sand discharge chamber and the ilask and operates to increase the sand receiving volume of the mold v cavity. After sand is discharged into the enlarged' mold cavity, the spacer member may be removed 'andthe sand compacted in the tiask or core box by repeatingthe' clamping action of the lift table to form a sand mold or core capable of resisting deformation under pressure of poured metal. Different spacer members may be used to vary the density of the sand. In conjunction with the -fore-v going, the lift table is controlled during removal of the spacer member to prevent separation of the mold from the pattern.

Additional objects and advantages of the improvements embodied in this invention will be apparent from the following description, the appended claims and the ac-f` Fig. 2 is a horizontal section taken along the plane of the ask supporting rails with the liask removed in Fig. 1;`

Fig. 3 is a plan view of an interchangeable spacer memb'er for increasing the mold cavity volume;

the rails 22 and 23 may be provided with extensions to support a line'of asks or core boxes for successive presentation to the core blowing apparatus. Movement of the line would be periodically lnterrupted during the sand blowing operation and then resumed to present an empty ask or core box above the t table 25 while the completed mold or core is discharged at the other end of the line. The ask lift table 25 is supported on a movable main plunger 26 in alift cylinder 27 which is disposed'within the base for operation in a conventional manner (Pigs. 6 and 8). The lift table 25 is also provided with an auxiliary plunger 30 at its forward extremity which is disposed in a cylinder housing 31 forming part of the base 10. The main plunger 26 and the spaced auxiliary plunger 30 coact on the base to prevent rotation of the table 25 and are operated by hydraulic pressure of oil or Ythe like to control the movement of the lift table in a manner to be hereinafter more fully described. Y

In normal operation, a drag pattern 17 or a cope pat- L tern corresponding to the type of liask 13 mounted on the rails 22 and 23 would be positioned above the lift table 25 and uid under pressure applied to lift the pat tern and flask against the blow-plate assembly 16 of the sand chamber to form a Vsand receiving mold cavity as shown in Fig. 6. Blowing pressure is supplied'to the chamber 15 through suitable conduits like 33 and' con? trol valves like 34 which may be controlled at the control panel 35 to discharge sand from the chamber 15 into the mold cavity. After formation of the mold or core i has been accomplished, the control valves can be op-V erated to terminate the blowing cycle and exhaust the chamber 15 through the stack 36. The controls may be selectively manipulated or maybe coupled together toA provide an automatic sand blowing cycle.

In order to increase the eliciency and production of the apparatus, the patterns are mounted on plates 38 and 39 respectively and each plate is in turn mounted in xed predetermined position ona multiple pattern carrier assembly which can be moved to selectively position either the drag or the cope pattern plate below the flask rails 22 and 23 and above the lift table 25.

Referring now particularly to Fig. 2 in conjunction with Fig. 1, the pattern'carrier assembly is shown as em Jbodying a support 40 having a pair of legs 41 and 42 dis-A posed at right angles to each other and mounted for' rotation about the column 12 with its vertex coincident with the vertical axis of the column. Each leg of the support 40 carries an open-ended : frame 44 and 45 and the length of each -leg .is selected lso vthat the path of travel of each -frame 'will intersect the lift table 25 when the support 40 is rotated. The frames 44 and 45 have `a substantially `U-shaped conguration which is complementary to the periphery of the lift table 25. Their open ends face inwardly towards the lift table .so that when they are rotated `in the plane of the table 25 they `will partially encircle the table and support the corresponding pattern above the table. Each vframe pattern carrier is provided with suitable pattern location holes 46 and `47 which are adapted to receive pattern plate guide pins, .and the lift table 25 is -also 'provided `with suitable dowel pins 48 and 49 for alignment with corresponding guide openings .in the pattern vplates all of which reduces time and eiort in handling.

The mounting .of the support 40 on the column 12 is accomplished by encircling the column 12 with a rotatable sleeve 50 which `carries radiallyprojecting :arms '51 and 5 2 vto which the support 40 is connected. With this arrangement, while oneppattern and flask are clamped fin sand blowing relation with the chamber ,15 and a mold or core is being formed, an operator can be preparing another pattern on the other carrier for presentation to -the sand blowing apparatus. Usually, in simple molding, the drag pattern would `be mounted on one carrier vand the cope pattern on the-other carrier so that 'the two halves of the `mold could be made in rapid succession. The. pattern carrierassemblymay be rotated on the column 12 by hand, or as shown in preferred form in the drawings, may be positioned by locating a motor 55 on a platform S6 on .the basel 10 andproviding .a friction wheel 58 on the motor `shaft to Afr-ictionally engage .and rotate the carrier support 40 about its axis. The driving motor 55.may -be energized through the medium of-.conventional reversing `switches toautomatically present selected ,pa-tterns in predetermined sequence.

After the .ilask vor core box 13 has been -lled with sand, the sand may be compacted so that it will resist deformation under pressure of poured metal. In accordance with this invention, the compacting is preferably accomplished by introducing a spacer plate 60 between the top of the ilask 13 and the blow-plate assembly 16 of the sand chamber to increase the sand receiving volume of the mold cavity (Fig. 6). After the enlarged cavity is filled with sand to a certain density, the spacer plate 60 is removed and the lift table 25 clamps the bottom pattern plate and the flask 13 against the blow plateassembly to compact thesand in the reduced cavity. The density of the compacted sand will depend .upon the excess sand volume as determined by the thickness of the spacer plate `60. Hence, the sand density can be varied by `using different spacer plates. This eliminates the necessity for extra squeeze platens and results in a similar design and more efhcient operation.

The spacer plate 60 is of uniform thickness and has Van opening 62 corresponding substantially to the boundary area defined by the walls `of the ask 13 and is adapted to be aligned therewith. `4Since the spacervplate 60-and its opening 62 may vary with the desired sand density as well as the size and type of ask, provision is made to removably support any type of spacer plate in the work space between the flask vand the chamber blow plate assembly. This provision includes a U-.shaped .member 63 which is carried by a sleeve .64 concentrically mounted on the column 11 and rotatable on suitable `bearings Vas best shown in the partial section view 4in Fig. 4 offthe drawings. The member 63 carriessuitable dowel pins 66 and 67 which are adapted for alignment with openings 68 and 69 in the spacer plate 60.

Thus, once a particular ask 13 is placed on the ask rails 22 and 23 above the corresponding pattern .plate and 'before the lift table 25 `is activated, the spacer plate .60 is swung about the column 11 into the space bethe lift table 25f1owers the bottom pattern plate and the flask a distance suicient to permit removal of the spacer plate 60 by swinging Itlre'member 63 outwardly about the column -11 and to leave `a'volume of sand in excess 'of the reduced cavity defined by the lflask walls and the bottom pattern plate as best shown in Fig. 8 of lthe drawings. The lift table 25 is again moved to clamp the bottom pattern plate and flask against the blow plate assembly and the sand is compacted in the reduced cavity thus formed. After the squeezing operation, the lift table returns and deposits themold on rails 22 and withdraws the pattern. As Ywill `hereinafter be more fully ex plained, the draw speed is decreased during separation to protect the mold. Although the foregoing operations. may be accomplished by hand, the foregoing operations can be .automatically 1accomplished in predetermined sequence in a continuous sand blowing cycle ,by means of suitable conventional controls.

Since it is necessary to lower the lift table 25 suiciently to permit removal of the spacer plate 60 prior to the cornpacting operation, it will be apparent that in the construction of the apparatus disclosed there -must be a limit to the extent that the lift table may be lowered in order` to prevent separation of the pattern rplate 4vfrom the flask (see Fig. 7,). This is preferably accomplished in .accordance with this invention by controlling release of hydraulic uid from the cylinder housing 31 in such `a manner `as to provide a dashpot operation for the plunger 30. Thus, initially when fluid under pressure is applied to lift the table 25 it may :also be supplied to the cylinder 31 and, after the mold cavity is filled with sand and the main plunger v26 Vis lowered, the hydraulic uid is blocked `in the cylinder 31 to provide a limiting downward stop for lift table 25. The same arrangement is utilized to decrease the draw vspeed of the lift table during separation of the pattern from the mold. Operation of the dashpot can be controlled by conventional valves and the like and by adjusting the stroke of the plunger 30 in the cylinder 31.

Thus, there has been providedan improved sand blowing apparatus for making sand molds and cores or the.

like an-d having a more eilicient and highly productive arrangement for presenting the `proper patterns and for removing and unloading the completed molds or cores. There has also been provided a simple arrangement for utilizing the main lift table in conjunction with a spacer member to permit compacting of the sand within the mold cavity. The latter arrangement includes an Virnproved .dashpot type limit for the lift table movement to prevent separation of the pattern from the mold while the spacer plate is being removed prior to the sand compacting operation and to reduce the draw speed during separation of the pattern from the mold. The improved apparatus permits the making of cope and drag on a single `machine and provides greater accessibility for inspection `and replacement of patterns during operation. Each of these improvements contribute to the overall efliciency and to increased production in a manner that results in the optimum formation of sand molds and cores which are sutliciently compressed to withstand metal pressures in later use.

I have shown and described what l consider to be theV preferred embodiment of my invention along with suggested modied forms, and it is clear that other changes and modifications may be made by those skilled vention as defined by the appended claims.

l claim:

1. ln a sand blowing apparatus having a frame including a pattern support adapted to be surmounted by a ask or core box, a multiple pattern carrier rotatably mounted on the frame and adapted to support independent patterns in spaced relation from each other, said carrier having at least a pair of circumferentially displaced carrier portions each adapted to independently support a pattern thereon, the displacement being such that while one pattern is positioned by the carrier in operative position on the pattern support at least another pattern is accessible to an operator external to the support and frame, said pattern support comprising a lift table adapted for vertical movement relative to the frame, each of said carrier portions including an open-ended frame disposed with the open ends facing each other on opposite sides ofthe lift table, each of said open-ended frames deinng,

a boundary complementary to the peripheral configuration of the lift table, whereby vertical movement of said table will lift the pattern away from the carrier and towards the surmounting ask or core box.

2. In a sand blowing apparatus having a frame including a vertical column disposed adjacent a pattern support, said pattern suport being adapted to be surmounted by a. ask or core box, a multiple pattern carrier rotatably mounted on the frame column and adapted to support independent patterns in spaced relation from each other, said carrier having at least a pair of circumferentially displaced carrier portions each adapted to independently support a pattern thereon, each of said carrier portions comprising an open ended frame dening a boundary complementary to the peripheral conguration of the pattern spaced sand discharge chamber and a bottom pattern eleed to independently support a pattern placement being such that when one pattern is positioned by the carrier in operative position with respect to the clamping member at least another pattern is accessible to an operator external to the clamping member and each of said open-ended frames dening a boundary genverally complementary to the peripherial configuration of the clamping member, a spacer member, means rotatably mounted on said apparatus frame above said ask or core kbox support and above said carrier for supporting said spacer member in a plurality of positions with respect to said sand receiving cavity, said spacer member being selectively movable into and'out of the space between the discharge chamber and sand receiving cavity depending upon the direction of rotation of said means and being vertically movable with respect to the latter when engaged by said iiask or core box, saidspacer member having an opening therethrough of a coniguration substantially coincident with the ask or core'box walls of the sand receiving cavity when said means is rotated to position said spacer member into said space, whereby the volume of the enclosed cavity is increased bythe thickness of the spacer member, said clamping member being operative upon upward movement thereof to lift the pattern element away from said carrier, the ask vor core box away from its support, and the spacer member away from its supporting means, all towards said sand discharge chamber, and

claim 3 wherein said rality of vertical columns disposed generally adjacent said -said spacer member there aek or core box, and meanson `said spacer plate adapted lfor interlocking coaction in a means for selectively limiting retraction of said clamping member to permit outward rotation of said spacer mem- I.her supporting means and resultant removal of the spacer l member from said y,element from the ing member may space without separation of the pattern ilask or core box, whereby said clampbe reapplied to compact the sand in the lesser sand receiving cavity with the spacer member removed.

v4. In a sand blowing apparatus in accordance with vapparatus frame comprises a plu- `clamping member, said carrier being rotatably mounted on one of said columns, said spacer member supporting means being rotatably mounted on another of said columns, said spacer member rsupporting means comprising a sleeve element concentrically mounted in movable re- .lationship on said othercolumn and a generally horizontally extending U-shaped arm element for supporting lon, said spacer member comprising an interchangeable spacer plate having an opening corresponding to the particular type and size of associated said arm element and on horizontal plane to align the spacer plate opening with the flask or core box opening.

References Cited in the le of this patent UNITED STATES PATENTS 1,021,938 MacKay Apr. 2, 1912 1,367,079 Nicholls Feb. 1, 1921 1,740,766 Campbell Dec. 24, 1929 2,012,478 Oyster Aug. 27, 1935 2,489,810 Oyster Nov. 29, 1949 2,632,215 Lee Mar. 24, 1953 FOREIGN PATENTS 543,832 Germany Feb. 15, 1932 824,543 Germany Dec. 13, 1951

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