US3326272A

US3326272A - Pressure casting molds

Info

Publication number: US3326272A
Application number: US437140A
Authority: US
Inventors: Johannes M Uys
Original assignee: Youngstown Sheet and Tube Co
Current assignee: Youngstown Sheet and Tube Co
Priority date: 1965-03-04
Filing date: 1965-03-04
Publication date: 1967-06-20
Anticipated expiration: 1984-06-20

Description

June 20, 1967 J. M. uYs

PRESSURE CASTING MOLDS Filed Maron 4, 1965 v 3 MII I I l 1 1 INVENTOR. JOHANNES M. UYS

ATTO/MEX FIG.

United States Patent O 3,326,272 PRESSURE CASTING MOLDS Johannes M. Uys, Youngstown, hio, assiguor to The Youngstown Sheet and Tube Company, Youngstown, Ghio, a corporation of Ohio Filed Mar. 4, 1965, Ser. No. 437,140 7 Claims. (Cl. 164-323) ABSTRACT F THE DISCLOSURE In pressure casting apparatus an inclined mold in which a movable block insertable through any one of several slots in the mold top permits modification of the effective volumetric capacity of that part of the mold cavity communicating with a sprue passage at the mold bottom through which molten metal is introduced into the cavity.

This invention relates to the pressure casting of metals and more specifically ferrous ones to fonn slabs for further processing in the manufacture of sheets, plates and other shapes by successive rolling, drawing and other physical reducing operations, and is particularly directed to means for conserving the metal remaining in the ladle when insufficient in amount to form a slab of standard size after one or a plurality of such slabs have been cast.

For maximum efficiency reduction of slabs to sheets or other shapes contemplates that the slabs successively rolled or to be rolled in a specified roll stand be of substantially uniform width and thickness although variations in length in the direction of rolling are acceptable and cause no appreciable impairment in the effectiveness of the operation, and it has been the practice in producing the slabs by pressure casting to fill successively a plurality of substantially identical molds from a single charge of molten metal in a ladle. This frequently results after a series of molds have been filled in leaving in the ladle of quantity of molten metal insuflicient to fill another such mold and hence if teemed into one there is produced a slab of non-standard and non-uniform width requiring special treatment in the rolling mill or, as is more usual, consignment to scrap of an unduly large weight of metal either from the ladle or after it has cooled in the mold.

It is therefore a principal object of this invention to provide for combination and association with pressure casting apparatus means, more particularly a mold, in which slabs of standard width and thickness but of nonstandard and variant length may be cast whereby a quantity of molten metal in a ladle insufficient for producing a slab of standard dimensions may be used for casting one shorter than standard but otherwise substantially conforming to the requirements of the rolling mill or other apparatus in which it is to be further processed.

A further object is to provide a mold suitable for pressure casting the cavity of which is adjustable as to length and consequent volume without varying those dimensions of the cavity which determine the width and thickness of a slab cast therein, with the result that the volume of the mold cavity can be correlated in advance to the quantity of residual metal in the ladle, if any, following the filling of a plurality of standard molds to thereby enable production from that metal of a final slab of standard width and thickness but less than standard length.

A still further object is the attainment of these and other objects by the provision of relatively simple means readily adaptable to existing pressure casting molds and which may conveniently be brought into play to form a slab of reduced length after the major portion of the metal initially in the ladle has been exhausted.

Other objects, purposes and advantages of the invention ice will hereinafter more fully appear or Iwill be understood from the following description of a preferred embodiment of it illustrated in the accompanying drawing in which:

FIG. 1 is a diagrammatic vertical section of pressure casting apparatus of known character with which there is shown associated and combined a typical mold constructed in accordance with the invention and disposed in metal-receiving relation to other components of the apparatus;

FIG. 2 is a somewhat enlarged fragmentary detail of one portion of the mold top and sides;

FIG. 3 is a corresponding fragmentary detail showing the rear end of the mold blocked off and excluded from access by the metal introduced into the mold near its front or lower end, and

FIG. 4 is a diagrammatic vertical section in the plane of the inner face of the side wall nearest the observer of a modified embodiment of the invention in which supplemental means for stabilizing the back block are provided.

Referring now more particularly to the drawing the pressure casting apparatus diagrammatically illustrated therein which is typical within known practices will first be briey described as the disclosure of the details of its modification in accordance with the invention will thereby be rendered more readily susceptible to comprehension by those skilled in the art. Thus said apparatus comprises a refractory lined steel ladle 1 preferably mounted on a suitable truck 2, comprising wheels 2', supporting a receptacle 3 in which the ladle is received for movement rectilinearly along rails 4. A removable canopy or hood 5 cooperative with the receptacle encloses the ladle and with it defines a sealable chamber into which air under pressure may be admitted from a manifold 6 through a separable -connecting conduit 7 adapted to carry air for example at about 55 p.s.i. from the manifold and pasta control valve 8 to the interior of the chamber. Jacks 10 of usual construction are provided for raising and lowering receptable 3 and its burden relatively to truck 2 and the usual means such as a scale (not shown) associated therewith enable the operator to determine by observation the weight of molten metal in the ladle at any time and in turn whether sufficient metal remains after a plurality of molds and have been filled to cast another full sized slab or only enough to cast one of less than normal weight.

These are other variations of pressure casting possible such as where the molds are mounted on a mold carriage and the ladle and pressure vessel are stationary. In this case the ladle and pressure vessel can be jacked up to make contact with the mold or the front part of the mold can be `lowered to make the contact.

Further in accordance with customary practice hood 5 is equipped with a refractory lined depending standpipe 12 which when in operative position extends from the top of the hood into ladle 1 just short of its bottom to provide a Siphon tube into which the molten metal may be forced for ejection from the standpipe when the upper end of the latter is connected with a fitting 13 depending from the proximate end of a superjacent mold 14, a gate 13 in the fitting permitting the passage through the latter to be closed after the mold has been filled. Fitting 13 here shown in association with the mold 14 embodying the invention may be substantially identical with those customarily utilized with pressure casting molds as is the superjacent riser 15 in the top of the -mold and the several components of the latter are of course removably secured together in the usual or other convenient way to enable their separation sufficiently to permit removal of the solidified metal mass or slab after it has cooled.

Similarly to pressure casting molds of generally like character currently yin use mold 14 comprises a bottom 16 preferably disposed at an angle to the horizontal such that it slopes toward the tracks at approximately 3, parallel side walls 1718 normal to the bottom, a top 19 parallel thereto, a stationary back block 20, including the customary porous vent block 21, and a front wall 22, all of recti- -linear form and together defining a generally rectilinear moldcavity 23. In accordance with my invention, however, the top is provided with a series of slots 24 spaced longitudinally from each other, preferably rectangular in shape and extending entirely across the top from one side wall to the other, through any of which a movable back block 25, desirably having at its upper end a vent block 26 substantially similar to vent block 21 in the back wall of the mold, can be entered and pushed down till it engages the mold bottom, thereby to adjust at the will of the operator the size of the mold cavity connected with fitting 13 to a capacity only slightly less than the amount of metal remaining in the ladle after the bulk of it initially present therein has been expended in filling one or more molds of normal capacity. Flanged graphite plugs 30 desirably carrying bails 31 may be utilized t-o close those of the slots between the front end of the mold and that through which the movable back block 25 is entered while as illustrated in FIG; 4 if additional support for the back block to insure against its canting in the mold under pressure of molten metal against its fr-ont face -is` deemed advisable angles 35, 36 or other appropriate means secured to the mold top may be disposed against its opposite sides projecting above the top.

Reference will now be had to the normal casting cycle in a pressure casting unit comprising a ladle, say, of to 300 tons capacity with associated hood, carriage, air pres- Vsure applying means and the like: After the ladle has received a charge of molten -metal and the hood replaced and sealed, truck 2 is moved along the tracks till aligned with one, usually the first, of a series of ordinary pressure casting molds and the siphon tube 12 is connected to fitting 13 -thereof with gate 13 open. Air pressure is next applied t-o the interior lof the hood, forcing molten metal from the bottom of the ladle into the superjacent mold until it rises in riser 15 far enough to compensate for the angularity of the top and bottom of the latter which meanwhile is being vented through vent block 21 in its back block. After a sufficient amount of metal has been poured :gate 13 in fitting 13 is actuated to close the sprue passage and the air pressure in the hood is then relieved as by actuation of a pressure relief valve (not shown) to enable the ladle to be lowered and moved to another, generally the next, mold in the series disposed at intervals along the tracks. Such molds if intended for casting ferrous slabs are customarily from 102\6' long, 20"-100" high, measured normal to the mold bottom, 3-15 wide between the side walls, and thus hold from about 1 to about 65 tons of metal when fully charged. It is but seldom, however, u'nder practical conditions of operation, that the ladle is initially charged with substantially exactly the right amount of metal to fill a given series of molds, with the result that it contains either more than sufficient to completely fill the entire series or only enough to cornpletely fill all but the last thereof; in either case a certain amount of residual metal is left in the ladle after the maximum number of molds have been poured full. Hence, if conveniently, the last mol-d in the series is constructed in accordance with my invention, the operator after filling of all the other molds can determine by observation of the lusual scale showing the weight of metal in the lad-le that there remains in the latter an insufficient quantity to fill another standard mold and he then adjusts the improved mold, by appropriate disposition of movable back block 25, to decrease the volumetric capacity of the cavity between it and the front wall to accord substantially with the amount of residual metal in the ladle so that when it is introduced into the shortened cavity it will substantially fill it with resultant production of a slab save in respect to length having the same dimensions as one cast in any other mold in the series.

It will now be appreciated it is not contemplated that in connection with each pressure casting unit a plurality of molds constructed in accordance with rny invention will ordinarily be provided since it usually is suicient to have but one in each series of molds of dimensions corresponding at least in all but length to the other molds therein, although the individual molds may differ in length if desired, since the subsequent processing as noted is not seriously affected by lack of length uniformity in a given group of slabs as it is by variations in one or both of their transverse dimensions.

While the foregoing discussion has been directed primarily to the casting of ferrous metal slabs it is not to be inferred thereform my invention may not be used advantageously in the pressure casting of non-ferrous metals and other materials while changes and modifications in the form, structure, arrangement and relationship of the several parts and components of my improved molds as herein described will readily occur to those skilled in the art and may be made if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent of the United States:

1. In pressure casting apparatus comprising a track, a series of hollow molds disposed at intervals along said track, a ladle adapted to contain molten metal movable on said track relatively to said molds for disposition selectively into proximity to any of said molds and pressure means for transferring molten metal from the ladle to the cavity of the mold in proximity thereto, that improvement which consists in providing in the top of a mold a series of slots communicating with the mold cavity, a back block insertable through any slot to prevent the passage of metal from one part of the cavity to the other, an-d means for closing the slots communicating with that part of the mold cavity on the metal entering side of the block.

2. In pressure casting apparatus comprising a series of hollow molds disposed at intervals proximate to and inclining downwardly toward a track, each providing a rectangular cavity defined by a bottom, side, back and front walls and a top, and means for transporting molten metal longitudinally of said track to the proximity of each mold and injecting it through an opening near the lower end of the mold cavity, that improvement which consists in the provision of a series of slots in the top of a mold in the series at intervals between its front and back walls, a removable -back block insertable through any of said slots to divide the mold cavity into two parts and prevent passage of metal from that part of the cavity proximate the lower end of the mold to that part proximate the back end thereof, thereby to define a metal receiving cavity of less capacity than the cavities yof other molds in the series, and removable means for closing the slots between that receiving said block and the front end of the mold.

3. In pressure casting apparatus comprising a track, a series of hollow molds disposed at intervals proximate to and inclining downwardly toward the track, each providing a rectangular cavity defined by a bottom, side, back and front walls and a top, means for transporting molten metal along said track to the proximity of each mold and injecting it through an opening near the lower end of the mold cavity, that improvement which consists in providing the top of a mold in the series with a plurality of transverse slots extending between its side walls, a removable back block selectively insertable in any slot to thereby divide the mold cavity into a front and rear part each of less volume than the unobstructed mold cavity, and removable means for closing the slots between said block when so inserted and the front end of the mold thereby to provide a substantially closed cavity for the reception of metal from the pressure injecting means to form a slab of less length but of dimensions otherwise similar to slabs formed in the other molds in the series.

4. In pressure casting apparatus comprising a mold including a top, side and end walls and a bottom, a subjacent ladle adapted to receive molten metal and a severable conduit for conveying the metal upward from the ladle to the mold, the mold top having a plurality of slots extending transversely between the side walls, a back block removably entered in one of the slots and adapted to confine molten metal within the mold between the block and one end wall, and means entered in the other slots for closing them to inhibit escape of molten metal from the mold through such slots.

5. Apparatus as defined in claim 4 in which the removable back block comprises an air permeable portion disposed adjacent the mold top when said block is entered in any slot for emission of air from the mold cavity as molten metal enters thereinto.

6. Apparatus as defined in claim 4 in which each of said means entered in said other slots comprises a anged block and a bail carried thereby.

7, In apparatus of the character described, a mold having a top and bottom with their upper and lower faces disposed in parallelism at an angle to the horizontal, a fitting adjacent its lower end defining a sprue passage communicating with the interior of the mold, and a riser aixed to the top dening a substantially vertical passage likewise communicating therewith, front, side and back References Cited UNITED STATES PATENTS 416,706 12/1889 Aiken 249-158 443,785 12/1890 Nimmo 76-112 684,773 10/1901 Anderson 249-158 X 888,133 5/1908 Welsh 249-155 1,331,919 2/1920 Heiby et al 22-209 2,020,373 11/1935 Petzold 249-158 X 2,154,234 4/1938 Eppensiner 249-158 X 3,032,841 5/1962 Sylvester 22-64 X 3,222,735 12/1965 Sylvester 22-69 3,196,503 7/ 1965 Sylvester 22-69 I. SPENCER OVERHOLSER, Primary Examiner.

R. S. ANNEAR, Assistant Examiner.

Claims

1. IN PRESSURE CASTING APPARATUS COMPRISING A TRACK, A SERIES OF HOLLOW MOLDS DISPOSED AT INTERVALS ALONG SAID TRACK, A LADLE ADAPTED TO CONTAIN MOLTEN METAL MOVABLE ON SAID TRACK RELATIVELY TO SAID MOLDS FOR DISPOSITION SELECTIVELY INTO PROXIMITY TO ANY OF SAID MOLDS AND PRESSURE MEANS FOR TRANSFERRING MOLTEN METAL FROM THE LADLE TO THE CAVITY OF THE MOLD IN PROXIMITY THERETO, THAT IMPROVE MENT WHICH CONSISTS IN PROVIDING IN THE TOP OF A MOLD A SERIES OF SLOTS COMMUNICATING WITH THE MOLD CAVITY, A BACK BLOCK INSERTABLE THROUGH ANY SLOT TO PREVENT THE PASSAGE OF METAL FROM ONE PART OF THE CAVITY TO THE OTHER, AND MEANS FOR CLOSING THE SLOTS COMMUNICATING WITH THAT PART OF THE MOLD CAVITY ON THE METAL ENTERING SIDE OF THE BLOCK.