US3206812A - Method for conditioning ingot mould molds and the like - Google Patents

Description

Sept. 2l, 1965 c. H. BARNl-:TT 3,206,812

METHOD FOR CONDITIONING INGOT MOULD MOLDS AND THE LIKE Filed June 18, 19,62 5 Sheets-Sheet 1 FIG IN VEN TOR.

I3) L3 23j m82 @a FIG 4 ATTORNEYS CHARLES H. BARNETT Sept. 21, 1965 c. H. BARNETT METHOD FOR CONDITIONING INGOT MOULD MOLDS AND THE LIKE Filed June 18, 1962 5 Sheets-Sheet 2 FIG 3 FIG 5 INVENTOR. CHARLES H. BARNETT Oberlin, mky Donnelly ATTORNEYS Sept. 21, 1965 c. H. BARNl-:TT 3,206,812

METHOD FOR CONDITIONING INGOT MULD MOLDS AND THE LIKE Filed June 18, 1962 3 Sheets-Sheet 3 United States Patent O 3,206,812 METHUD FR CON'DI'HUNING INGO'I MOULD MOLDS AND THE LIKE `Charles H. Barnett, Shaker Heights, hio, assignor to The Foundry Equipment Company, Cleveland, Ohio, a corporation of Ohio Filed June 18, 1962, Ser. No. 203,226 2 Claims. (Cl. 22-200) This invention relates generally, as indicated, to a method for conditioning ingot mould molds and the like and more particularly this invention pertains to la unique mold and core drying oven and the foundry application thereof.

When green sand is formed into foundry molds for the formation of ingot moulds, it is necessary to subject such green sand molds to a baking and drying operation in order to set the binder in the sand `and -to dispel the d-ampness therein to provide mold surfaces capable of producing a satisfactory ingot mould casting. The size of the mold required to produce an ingot mould presents considerable handling and assembling problems and extremely large ovens provided with tracks or cars for the trundling of the assembled molds therein have had to be provided. The drying and baking of the sand molds must be thorough since a damp sand mold of the size under consideration may cause a steam blow. The molds should ordinarily be dried for a substantial period on the order of hours and at a temperature of at least 450 F.

In some instances, the molds may be placed upon a continuous conveyor to be passed through the drying oven, but the expense of operation and .size of such apparatus, especially that required to support yand transport the extremely massive molds under consider-ation, make the drying of ysuch molds an expensive task requiring a large installation. Maintenance of cars and track systems in old style ovens is always a serious problem and a major expense. Moreover, c-ars and tracks sometimes become distorted by the extreme heat in the ovens so that the cars become difficult to move. This may, in turn, distort the mold and also cause molds to fall over damaging ovens and injuring workers. The amount of space required and the time consumed in placing the molds within the ovens and removing them for subsequent cooling Aand pouring is extreme.

It is `accordingly a principal object of the present in- Vention to provide a novel method for preparing ingot mould molds which will require less time and less space.

It is a further main object to provide a mold drying apparatus which can be employed to the greatest advantage in the production of ingot mould molds.

It is a further object to provide such ingot mold drying apparatus which can readily and easily be employed in the drying of the largest molds which will uniformly and evenly dry such molds so as to produce superior mould castings.

It is yet another object to provide a mold drying oven wherein a portion of the oven may be moved about the foundry to cooperate with pits so that the ingot mould molds may be dried therein and subsequently cooled and poured within such pits without being moved in the interim.

A still further object is the provision of a drying and heating unit for ingot mould molds which is adapted to heat and uniformly dry the entire surface of the cheek and core of such ingot mould molds and in a short period of time since the cheek `and core are put together and left together without being picked up and moved again thus cutting down handling time.

Other objects and advantages of the present invention will become `apparent as the following description proceeds.

T-o the accomplishment of the foregoing and related ends, the invention, then', comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a view of one form of oven in accordance with the present invention with such oven being partially broken away in section and partially in elevation;

FIG. 2 is a top plan view of the oven of FIG. l;

FIG. 3 is a transverse section taken substantially on the line 3--3 of FIG. 1;

FIG. 4 is a schematic illustration showing the manner of application of the oven apparatus shown in FIGS. l through 3;

FIG. 5 is a longitudinal section of another slightly modified form of ingot mould mold drying oven in accordance with the present invention;

FIG. 6 is a top plan view of the oven of FIG. 5;

FIG. 7 is an end elevation of the oven olf FIG. 5; and

FIG. 8 is an operating plan view showing the manner of application of the oven disclosed in FIG-S. 5, 6 and 7.

Referring now to the annexed drawings and more particularly to FIG. 1, there is illustrated an oven enclosure 1 which is comprised of a cover 2 and a pit 3, with the cover being set or resting on top of the pit 3 to form the enclosure 1. The pit 3 may be formed of reinforced and insulated concrete side walls 4 and a bottom reinforced concrete wall or oor 5, both situated beneath the foundry floor line 6. A top support member 7 may be provided adjacent the pit end wall 4 rand such end wall may be provided with a footing 8 `supporting the oven structure. Similarly, a cover support wall 10 may be provided in the pit with la footing 11 positioned therebeneath. As seen in FIG. 4, side cover support walls 12 and 13 may also be employed within the pit 3.

Shown within the oven enclosure 1 in FIG. 1, there are two assembled molds which are in position to be dried and baked by the oven apparatus. Such assembled molds are set upon barrel drags 1S which support the core 16 extending upwardly centrally therefrom and such cores are generally the same size as the ingot to be produced. The sand cores are generally rammed or molded about a steel arbor projecting upwardly from the drags 15. Mounted on spacers 17, four in number for each of the illustrated assembled molds, are the mold cheeks 18, When the spacers 17 are recoved and the cheek is clamped to the drag, the sand mold will be ready for pouring to produce the ingot mould. However, in the assembled position shown, heated air may be blown through the opening 19 in the top of the assembled mold and out through the substantially annular opening 20 adjacent the bottoms of the mold. These assembled molds may then be placed `directly in the pits within the foundry floor and the oven cover 2 may be positioned over the pit to form the oven enclosure 1 whereby the sand molds and cores may be baked and dried. The cover supporting end walls 7 and 10 are provided with a plurality of iiues as shown at 22 and 23 respectively which have inwardly directed openings 24 and 25 respectively adjacent the bottoms of the pits and substantially aligned with the openings 2t) in the assembled molds.

When the cover 2 is placed upon the pits, corresponding iiues 27 and 2S will be vertically aligned with the flues 22 and 23 which will draw the heated air from the mold back into the combustion chamber of the cover for reheating and recirculation. The frame of the cover ernbodies an open bottom housing which fits down on top j of the cover support walls of the pit. The frame is made up of a top and bottom rectangular frame shown at and 31 which are vertically spaced by a series of vertically extending frame members 32 with the horizontally and vertically extending frame members being interconnected by gusset plates or the like shown at 33. Tie rods or the like may, of course, be employed interconnecting the corners of the various rectangular frame sections provided in the overall frame further to rigidify the same. Insulating panels may be provided within the framework as shown at 35 and 36 to provide a rectangular open bottom insulated cover, the bottom edge of which terminates in a channel 38 which provides an air seal with the top of the cover supporting walls within the pit.

Referring now more particularly to FIG. 2, it will be seen that a number of vertically extending angle members 40 serve further to rigidify the frame, with the vertically extending frame members 32 spaced from the corners of the frame being composed of such angle members. Two channel- shape cross-stringers 41 and 42 extend between the vertically extending angles 40 disposed at the sides of the frame and the vertically extending angles at the corner of the frame thus formed extend beyond the top of the frame and terminate in lifting eyes as shown at 43 and 44. Diagonally extending braces as shown at 45 and 46 may be employed further to support the lifting eyes spaced vertically above the frame. Extending between the transverse stringers 41 and 42, there is provided longitudinally extending stringers 48 and 49 which support the end edges of a combustion chamber 50, one side edge being supported by the stringer 41. The other side edge is supported by a stringer 51 extending between the stringers 48 and 49. A motor driven combustion air blower 52 is mounted on channel- shape stringers 53 and 54 adjacent the combustion chamber and such combustion air blower 52 supplies :air to a burner as shown at 55 extending within the combustion chamber 50. A pair of blowers 61 and 62 driven by motors 63 and 64 respectively through belt drives 65 and 66 supply heated air to longitudinally extending ducts 68 and 69 which are provided with a multiplicity of downwardly projecting nozzles as shown at 70. The heated air is then expelled from the combustion chamber 50 through the blowers 61 and 62 into the ducts 68 and 69 which then forces the air directly downwardly through the nozzle 70 into the openings 19 in the assembled molds. The hot air then passes directly over the surfaces of both the cores 16 and the cheeks 18 and exits from the assembled molds through the openings 20. The heated air expelled through the openings 20 is then picked upA in the flue openings 24 and 25 to be drawn upwardly through the flues 22 and 23 f into the recirculating duct 71 which passes the heated air back into the combustion chamber through the opening 72. The frame forming the combustion chamber is, of course, also provided with insulation panels as shown at 74 and 75 so that the entire top surface of the oven cover is insulated.

It is noted that a ladder 78 may be provided at the side of the oven cover leading to the control cabinet 79 mounted on the side of the combustion chamber. It can now be seen that the embodiment illustrated in FIGS. 1, 2 and 3 provides -a portable roven cover which can be placed upon specially constructed pits whereby the heated air from the cover can be forced through the assembled mold to dry and bake the sand surfaces thereof with such heated air being recirculated through flues within the pit walls and back into the cover for reheating and recirculation through the oven.

As seen in FIG. 4, it is possible to employ a single cover with an elongated pit whereby assembled molds or cores or cheeks separately may be baked and dried. In FIG. 4, the pit enclosure 80 may contain, for example, four assembled molds which are 8 x 6 feet. These assembled molds may be placed in the pit and the cover placed on top for the baking and drying operatiorL In the adjacent pit, B1, there is 4shown six 5 foot 6 inch by six foot assembled molds which may be baked and dried during the next turn while the molds in the pit 80 are cooled. The cover can be removed readily with an overhead crane to be placed on the pit desired and it can be seen that the assembled molds within the pits need not be removed from the pits for the cooling and pouring operation. The flue in the pit Wall 10 may be connected to a duct 82 extending beneath the aisle to a stack 83 which may in turn be connected to an appropriately permanently located exhaust fan and in this manner, when desired, both compartments may be exhausted.

Referring now to the embodiment of the invention illustrated in FIGS. 5, 6 and 7, it will be seen that there is provided an oven comprised of a rectangular box-like enclosure 8S which includes insulated end walls S6 and 87 and similarly insulated side walls 88 and 89. A top insulated wall 90 is provided with three openings 91, 92 and 93 which communicate with an expansion chamber 94 mounted on the top wall 90. The opening 93 cornmunicates heating flues 95 with the outlet of a recirculating blower 96 and the openings 91 and 92 communicate the expansion chamber 94 with recirculating ducts 98 and 99. A combustion chamber 100 mounted within the expansion chamber supplies heat to heat the air which is expanded in the chamber 94 which is then forced through the inlet 101 of the recirculating blower 96 to be forced into the ues 95 and then downwardly through the nozzles 102 in the flue 95, such nozzles being arranged in groups which are directed into the top openings of assembled molds 103, 104 and 105 within the oven enclosure 85, the illustrated embodiment showing three such assembled molds. Such molds may be the same as those shown in FIG. l and the heated air will pass downwardly directly impinging the surfaces of the sand cores and cheeks to flow outwardly through the annular openings 106, 107 and 108 adjacent the bottoms of the molds which are formed by the blocks which separate the jackets or cheeks from the core barrel drags. The heated air is then drawn by the recirculating blower 96 into openings 109 in a peripheral inside duct 110 extending about the entire inside periphery of the oven enclosure. Heated air is then drawn through the return or recirculating vertically extending ducts 98 and 99 which then pass the heated air back into the expension chamber through the openings 91 and 92 to be reheated and recirculated. The peripheral duct 110 and the openings 109 therein are at approximately the same elevation as the discharge openings in the assembled molds Such that the circulation of the heated air through the interiors of the assembled molds is readily facilitated. Exhaust blower 111 may alternatively be mounted on the top of the oven to be driven by motor 112 to exhaust the heated air from the oven when desired. The

blower 93 may be driven by a motor 113 as seen in4 FIG. 6 in the same manner that the blowers in the FIG. l embodiment are driven.

With special reference to FIG. 7, it will be seen that the top of the oven enclosure may be provided with one or more frames 115 secured directly to the top wall of the oven enclosure, such frames including horizontally extending top frame members 116 and vertically extending legs 117 and 118. This framework may readily be employed to facilitate the fastening of a crane lifting device to the oven enclosure whereby the entire oven may be raised and transported about the foundry.

Referring now particularly to FIG. 8, it can be seen that the portable oven apparatus of the present invention will greatly facilitate the operation of the foundry in the production of ingot moulds. As seen at the top in FIG. 8, various groups of assembled molds may be positioned adjacent a central pouring platform 120 with such assembled molds being arranged in strategically positioned groups of threes on each side of the pouring platform. During the first shift, oven enclosures 121 and 122 may be placed over the two groups of molds 123 and 124 for baking and drying. Previously dried and baked groups of molds 125 and 126 may be poured as shown in the center at 127. While at the far right of the pouring platform 125, the groups of molds 128 and 129, previously poured, may be cooled.

During the second shift, the previously dried groups of molds 121 and 122 may be poured while the previously poured groups of molds 125 and 126 may be cooled. The cooled groups of molds 128 and 129 may be replaced by further assembled molds as shown at 130 and 131 for the next drying operation. The same two oven enclosures employed to dry the groups of molds 121 and 122 may simply be shifted to the groups 130 and 131 for the second shift.

For the third shift, the previously poured groups of molds 121 and 122 may be left to cool as shown at the left during the third shift, while the cooled groups 125 and 126 may be removed and replaced by new assembled molds 132 and 133. The groups of molds 130 and 131 which were dried during the second shift may now be poured at the right as shown in the third shift while the newly assembled molds 132 and 133 are being dried. In this manner, the oven enclosures can be shifted from the various groups of molds during the succeeding shifts so that a continuous drying, pouring and cooling operation will proceed in an extremely limited space. In order to dry, pour and then cool the molds, they need not be moved from the positions indicated and, of course, no trundling of the molds on cars or conveyors is Iequired. The only thing required to be moved is the oven enclosures which can readily be accomplished by the employment of an overhead crane fastening to the provided lifting devices on the respective enclosures. If the molds are of an extremely large size, they can be placed in prepared pits as shown in FIG. 1 with only the oven cover being transported and such assembled molds can be left in the pits for the pouring and cooling operation.

It can now be seen that there is provided a unique method and apparatus for preparing ingot mould molds which eliminates much of the heretofore required mold handling and trundling, thus producing such molds more rapidly and with greater safety.

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

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

1. In a method of producing ingot moulds, the steps of forming a sand core and cheek, placing such core on a base in an upwardly extending position, placing the cheek over the core to form an assembled ingot mould mold with the cheek spaced from such core and said base to permit air circulation longitudinally through such assembled mold, placing an oven cover having a self-contained heating unit over said assembled ingot mould mold, forcing heated air from such cover downwardly through such assembled mold for drying the same and recirculating such air back to such cover for reheating the same, removing said cover, placing said cheek on said base, pouring metal into such mold, and cooling the poured mold in situ.

2. In a method of producing ingot moulds, the steps of forming a plurality of sand cores and cheeks, placing such cores on bases in an upwardly extending position, placing the cheeks over the cores to form assembled ingot mould molds with the cheeks being spaced from such cores and said bases to permit air circulation longitudinally through such assembled molds, placing an oven cover having a self-contained heating unit over the thus formed group of assembled ingot mould molds, forcing heated air from such cover downwardly through such assembled molds for drying the same and recirculating such air back to such cover for reheating the same, removing said cover, placing said cheeks on said bases, pouring metal into such molds as a group, and cooling the poured molds in situ as a group.

References Cited by the Examiner UNITED STATES PATENTS 82,065 9/68 Aston 22-87 516,397 3/94 Merchant 22-87 1,299,522 4/19 Walker 22-192 1,325,044 12/19 Poggel 34-13 2,367,648 1/45 Nichols 22f-192 2,385,962 10/45 Barnett 'S4-13 2,417,673 3/ 47 Barnett et al 22-87 3,060,534 10/62 Enzenbacher 22-192 OTHER REFERENCES Milwaukee Mold Dryer-Advertizement, by Milwaukee Ship-Building Corporation, May 1955, copyright 1955,

found in 22487, 8 pages.

I. SPENCER OVERHOLSER, Primary Examiner.

WILLIAM I. STEPHENSON, MICHAEL V. BRINDISI,

Examiners.

Claims (1)

1. IN A METHOD OF PRODUCING INGOT MOULDS, THE STEPS OF FORMING A SAND CORE AND CHEEK, PLACING SUCH CORE ON A BASE IN AN UPWARDLY EXTENDING POSITION, PLACING THE CHECK OVER THE CORE TO FORM AN ASSEMBLED INGOT MOUND MOLD WITH THE CHEEK SPACED FROM SUCH CORE AND SAID BASE TO PERMIT AIR CIRCULATION LONGITUDINALLY THROUGH SUCH ASSEMBLED MOLD, PLACING AN OVEN COVER HAVING A SELF-CONTAINED HEATING UNIT OVER SAID ASSEMBLED INGOT MOULD MOLD, KFORCING HEATED AIR FROM SUCH COVER DOWNWARDLY THROUGH SUCH ASSEMBLED MOLD FOR DRYING THE SAME AND RECIRCULATING SUCH AIR BACK TO SUCH COVER FOR REHEATING THE SAME REMOVING SAID COVER, PLACING SAID CHEEK ON SAID BASE, POURING METAL INTO SUCH MOLD, AND COOLING THE POURED MOLD IN SITU.

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