US2977648A - Stamped metal casting mold - Google Patents

Description

April 4, 1961 Filed April 29, 1957 s. F. SIMPSON 2,977,648

STAMPED METAL CASTING MOLD 3 Sheets-Sheet 1 1N VENTOR San/ey F. Simpson WM@ W.

ATTORNEY April 4, 1961 5 F, SIMPSON 2,977,648

STAMPED METAL CASTING MOLD Filed April 29, 1957 3 Sheets-Sheet 2 e Lf?? l a l e /Zf A22/ l /26 x l i I 22 /27 24 I l I 23 I A I I l l l i I 24/' 29 'L 30 I I I I 26 INVENTOR I 9 S'Gn/ey E Simpson www.

ATTORNEY April 4, 1961 Filed April 29, 1957 5 Sheets-Sheet 5 /20 /9 I I l I -//6 I I I I I l l I I I I I I /f l`| I l l/ i I I/I IZ/I @I #4@ l l I I A90 20a INVENTOR San/ey E Simpson BY mi ATTORNEY Stanley F. Simpson, Lehighton, Pa., assignor to vBethlehem Steel Company, acorporation of Pennsylvania Filed Apr. 29, 1957, Ser. No. 655,819

` V'2. Claims. (Cl. 22-57) Thisinvention broadly relates to casting. More particularly it relates to a new device for casting parts 1n a thin-metal mold adapted to be superior to other types of casting apparatus for certain applications in that it combines accuracy of cast dimensions, excellence of surface characteristics, and controllability of casting through quick cooling with convenience, cheapness, ease of fabrication, and small bulk and durability of the molds in storage.

Briefly stated this invention makes use of a pair of sheet metal stampings for the casting mold. The stampings, which are ordinarily used only once, are held together in clamped relationship by a backing member which, is fabricated from metal to provide a sufficient bulk of material to conduct heataway from the cast piece and to provide more or less accelerated cooling as may be desired for the particular casting. The backing member is ordinarily used repeatedly for any Vgiven shape or size casting unless it is desirable to alter the cooling rate in which case a backing member of greater or less bulk'may be used.

As is well known to kthose skilled in the art, the use of permanent steel molds is subject to certain real disadvantages, in that the molds have a relativelyV short service life. This is especially true where the piece must be cast to close tolerances and the protective coatings which are often applied to the mold cavity to protect its surface and prolong the life of the mold must be thin or eliminated entirely. Permanent steel molds are usually quite expensive particularly if the casting is to be rather intricate. Because of the destructive erosion ofthe permanent mold occasioned byA each casting made, frequent repairing of the mold is necessary'in orderto get any degree ofrservice life at all from the unprotected mold. Thereby the cost per casting tends to bev quite high. Often indeed the servicing of the mold is neglected to a greateror lesser extent for economy reasons, and this resultsin inferior castings which prove unusable for many applications. My invention obviates all these dilliculties since, my mold pieces are cheaply and easily made in large quantities and the used only once before being discarded. 'Ihus each casting ,is made in a new and unused mold and no service problem occurs. vThereby I am able to obtainall the numerous advantages of casting in permanent metal molds but at the same time preclude many of the most serious disadvantages of so doing particularly in quantity production.V

It will be obvious from what has been said that the invention described above will be useful in various applications where quick cooling, accuracy of dimensions, and good ysurface characteristics are important. t While I do not wish to restrict the use of my device to casting samples I will describe my inventionby reference to aparticular embodiment applicable tothe art o`f casting samples for chemical and spectrographic analysis,-

a use to which I have found it to be verywell adapted and which I believe particularlyV well villustrates the especial advantages and superiorities of my invention. 1

f United States Patil'fF y 2,911,648 Patented Apr. 4, 1961 In the iron and steel industry it has heretofore been a problem to obtain good cast samples of metals for use in spectrographic analysis. These samples are usually, cast in the form of small pins Due to the peculiarities of spectrochemical analysis 'it is extremely desirable and important that the sample pins be all of a uniform size and inish in order that accurate, uniform, and reproducible analytical results may be obtained; Heretofore with the various casting methods tried and available various difficulties havebeen encountered in that either the sample pins were not held to the neces# sary tolerances through variations in molds after use or in fabrication, or the molding apparatus was too expensive or required too highly skilled maintenance men.

I have found, however, thatv by the application of my invention of casting in stamped sheet metal molds vto the art of casting spectrochemical samples the problems `enumerated above have at last been overcome and a simple, cheap, convenient, accurate and reliable device for casting spectrographic and chemical samplesis at last at hand. The application of my invention to the sample casting art enables spectrochemical analysis pins v to be produced which are uniform and reliable, smooth of surface and free from porosity, and the casting device is cheap and easy to use, does not require skilled labor for its operation and the molds themselves take up little l space in storage and are not liable to damage or deteri oration.

The objects and advantages of my invention will be further apparent from the following description wherein reference is made to the accompanying drawings illusi trating the preferred embodiment of my invention when used for the casting of chemical and spectrographic samples and wherein similar reference numerals designate similar parts throughout the several views.

n Fig. 1 is an isometric View of the casting device.

Fig. 2 is a front elevation of the casting device with ya portion shown in section. v

Fig. 3 is a plan view of the same device with portions shown in section.

Fig. 4 is an inside front elevation of the stamped mold piece.

Fig. 5 is a transverse section of the stamped mold piece taken along 5-5 of Fig. 4.

Fig. 6 is a top view of the same stamped mold piece.

Fig. 7 is a section taken through the stamped mold piece along 7-7 of Fig. 4 and also shows how the mating stamped mold pieces nest together to form the pinv mold portions of the casting while in the clamped position inside the casting device.

Fig. 8 is an inside front elevation of one of the two back-up members.

Fig. 9 is a transverse section taken along 9-9of Fig.' 8 and also shows the locking block attached to the backup member. Y

Fig. 10 is a top View of a back-up member with locking block attached. l Fig. 11 is a top view with a portion in section of .the clamping member. v

Fig. 12 is a front view of the clamping member show; ing the thumping members and fork clamps.

Referring now to the drawings the numeral 11V designates a stamped sheet metal mold piece of my casting device. The numerals 12 and 12a designate the back-up membersywhich enclose and support the mold pieces 11 and 11a. The numeral 13 indicates the clamp member as a whole of the particular embodiment of my casting device. The clamp member 13 isl composed-of a sel tin of flat metal plate-machined intotwo fork members I14 and 14a connected by a cross piece designated asl'Sl; The rear portion of the cross piece 1-5l is slopedintoa" triangular shape withthe apex bisected by'a rectangule cut out portion such that two triangular projections of metal 16 and 16a are formed so arranged that there is a space between them in which the handle 17 is welded, the triangular pieces 16 and la'acting as braces on either side ofthe handle 17. To the top and bottom of the cross piece 15 are welded two pieces of channel 18 and 18a. To the opposite ends of the channel members 18 and 18a are welded small rectangular cap plates of hard shock'resistant steel 19 and 19a. Channels 18 and 18a and cap plates 19 and 19a combine to form the two so-called thumping members hereinafter referred to as thumping members 20 and 20a. The two opposite faces 21 and 21a of the fork members 14 and 14a are biased at a slight angle as may be seen in Fig. 2 so that they may better t the grooves in the back-up members as hereinafter described.

The back-up members 12 and 12a each consist of a truncated triangular prism-shaped piece of metal (which can be conveniently formed by bisecting a short piece of hexagonal bar stock) with subsequently machined portions such that 22 designates a hollow taking the form of one half of the specimen desired to be cast machined into the hypotenusal side of said truncated triangular prism. Numerals 23, 24 and 25 designate small halfround pin-shaped extensions of the main cavity 22.- Numeral 26 indicates a half-round cavity machined beside the mold cavity 22 but extending from one end of the back-up member to the other.

On the reverse side of both back-up blocks from the mold cavity is machined the long inclined groove 27 into which the fork members 14 or 14a are designed to t. At the bottom of the back-up member at the bottom or deeper portion of the inclined groove a right-angle sided portion of the back-up member is machined away at 28. Into this space 28 the locking block 29 tits and is held in place by the machined bolt 30.

The numeral 11 designating one of the two stamped sheet metal mold pieces, then 31 designates a stamped depression in the sheet metal piece which has inside shape and dimensions adapted to form one-half of a mold for casting the main body of a sample for chemical and spectrographic analysis. Numerals 32, 33 and 34 indicate three half round extensions of the main stamped impression 31 so arranged that when the two mold pieces 11 and 11a are clamped together the two sets of depressions 32, 33 and 34 will be in opposed relationship with each other and will so coact to form molds for three spectrographic pins pendant from the main body of the cast sample.

At the lower end of the three depressions 32, 33 and 34 are three small cross-sectional grooves 35, 36 and 37 leading from the bottoms of 32, 33 and -34 to the edge of the stamped piece 11. When the two stamped mold pieces are clamped in their operating opposed relationship these grooves will form vent tubes from the inside of the mold chamber to the outside of the device. Numeral 38 indicates two small spherical depressions and numeral 38a two slightly larger spherical depressions in the ange portions 39 of the stamped metal mold pieces. The two smaller of these spherical depressions are stamped so that they project on one side of the sheet metal piece and the two larger of them are stamped so that they project on the other side of the metal. (The two pairs should occur on opposite sides, left and right, of the mold cavity 21 so that only 1 half-round cavity 26 will be necessary in each back-up member as will shortly be explained.) In this way when the twomold pieces are clamped or placed in opposed alignment the undersides of the smaller depressions will project intov the larger depressions on the opposite mold piece as illustrated in Fig. 7, thus acting to hold the mold halves in lateral alignment. The half-round cavity 26 extending full length across the face of the back-up members 12 and 12a functions toY receive the convex sides of the larger spherical 4 ing the stampings 11 and 11a to slide to their full depth in the back-up members. The cavities are cut full length merely for convenience in machining. Obviously the half-round cavities 26 must be cut in the back-up members so that they occur on the correct side of the mold cavity to receive the underside of the larger depressions.

I will now describe the relatively simple manner in which my casting device may be operated.

The two identical back-up members 12 and 12a are rst held in opposed relationship with the long grooves 27 toward the outside. The two fork members 14 and 14a of the clamping member 13 are then inserted in the bottom of the grooves 27 and the two locking blocks 29 are inserted into the recesses 28 and secured in place by the machine bolts 30. The locking blocks 29 therefore act to keep the fork members 14 and 14a in the inclined grooves 27 so that the two back-up members 12 and 12a are held together more or less loosely in opposed relationship' as may be readily seen in the accompanying drawings. The two stamped sheet metal mold pieces 11 and 11a are next placed in opposed relationship so that the four spherical depressions 38, 38a are superposed suitably upon each other thus holding the sheet metal mold members in correct alignment. Next with the forked members 14 and 14a held in the deepest portion of the grooves 27 and the backing blocks 12 and 12a therefore having some play between them, the mold stampings 11 and 11a held in opposed relationship are slipped from the top into the space between the two backing blocks 12 Vand 12a, the undersides of the larger depressions 38a in the ange portions 39 sliding in the half-round grooves 2 6 machined in the backing blocks. When the mold pieces have slipped all the way to the bottom of the cut-out portion of the backing blocks 12 and` 12a such that the portion 31 of the mold pieces is seated in portion 22 of the back-up block and portions 32, 33 and 34 of the mold pieces are seated in portions 23, 24 and 25 of the backing block, the whole device is lifted and struck down sharply so that the bottom of the thumping' member 20a strikes on a substantial block or other raised surface such as a rail in such a manner that the momentum of the backing blocks 12 and 12a causes them to wedge themselves securely between the forked members 14 and 14a of the clamp member 13 clamping them together so that they tightly hold the stamped sheet metal mold pieces 11 and 11a so that their flanges are pressed tightly together within and between the clamping members.

The mold apparatus is at this stage ready to use and the-operator need only pour hot metal taken from whatever source (usually an open-hearth furnace) into the top of the mold where it will solidify in a very short period. The vent tubes formed by the small grooves 35, 36 and 37 allow air to escape from the bottom of the mold in order that it may not be trapped in the metal, particularly the metal of the spectrographic pins pendant from the main body of metal. The vent tubes have been found necessary because when using the particular wedging clamp member 13 as described herein the flanges 39 of the stamped mold pieces are pressed together so tightly that they become essentially airtight.. The main body of solidified metal is subsequently used for chemical analysis. The sheet metal mold pieces being new and unused will give la sample with no imperfections. The back-up plates 12 and 12a besides being the immediate members which hold the sheet metal molds together also have the important function of providing a body of metal suicient to carry the heat of the molten metal away from the mold before it burns through or welds to the thin sheet metal of the mold.

As soon as the metal casting has solidilied it may be removed together with the used mold pieces by merely reversing the apparatus and striking the'top of the thumping block 20 down against a non-yielding surface such depressions 38a during assembly of the apparatus allow- 75 as a steel rail. The device is then ready for the insertion of another mold pair and reclamping preparatory to the casting of another sample.

I believe it is apparent that my invention is not necessarily confined to the specific use or uses herein described above, since it may be utilized for any purpose to which it is suited. Nor is the invention to be necessarily limited to the `specific construction illustrated and described, since such construction is only intended to be illustrative of the principles of operation and the means presently devised to carry out said principles, it being considered that the invention comprehends any minor changes in construction that come within the scope of the claims.

I claim:

1. A spectrographic pin sample casting mold comprising a pair of thin sheet metal mold members formed by a stamping operation, each of said mold members having a depressed central portion defining one half of the ydimensional shapes of several spectrograph pins plus a combined metal reservoir and chemical sample body, and planar flanges adjacent thereto, one of said flanges having several relatively small spherical depressions stamped therein so that they project from one side of said flange and the other of said flanges having several relatively larger spherical depressions stam-pcd therein so that they project from the other side of said other flange,

said depressions being located in a manner such that when a casting mold is formed by opposing twov of said sheet metal mold members said relatively small spherical depressions will project into said relatively larger spherical depressions in order to facilitate and maintain the alignment of the mold sections, each of said flanges also having stamped thereupona half section of a vent tube leading from the bottom of each half section of a spectrograph pin sample mold cavity to the bottom edge of each dimensions as the outer side of the depressed central portions of the sheet metal mold sections and the outside portions of said opposed faces being planar to compress the flanges of the sheet metal sections therebetween, said planar opposed faces having appropriate grooves formed therein from top to bottom arranged so that the spherical depressions in the said flanges will slide down said grooves during assembly of the mold, the rear faces of the back-up members having cut therein grooves inclined inwardly towards the bottom portion of the back-up members, and a locking block located at the bottom end of said inclined groove, two opposed arms extending from the front portion of a main body member of a clamping means, the ends of said opposed arms being located in the inclined grooves on the rear faces of the back-up members in a sliding clamp relationship, said main body member having hard shock resistant steel impact receiving pieces secured at its upper and lower ends thereof and a handle for manipulation secured to the rear portion thereof.

2. A casting mold comprising a pair of thin-sheet metal mold members, each of said mold members having a depressed central portion defining one-half of a mold cavity, and planar flanges adjacent thereto, one of said llanges having at least one depression therein projecting from one side of said flange and the other of said flanges having at least one depression stamped therein projecting from the other side of said other flange, said depressions being so located that when a casting mold is formed by opposing two of said sheet metal mold members one of the depressions will project into the other to facilitate and maintain the alignment of the mold sections, said pair of sheet metal members being operatively positioned with their flanges in contact and their depressed central portions cooperating to define a central mold cavity, a pair of relatively massive metal back-up members of high heat transfer capacity engaging said flanges and also the outer walls of the depressed central portions of the sheet metal mold members defining the said central mold cavity, the central opposed faces of the said back-up members being formed with a depressed area of substantially the same form and dimensions as the outer sides of the depressed central portions of the sheet metal mold sections and the outside portions of said opposed faces being planar to compress the flanges of the sheet metal sections therebetween, said planar opposed faces having grooves formed therein from top to bottom arranged so that the depressions in the said flanges will slide in said grooves during assembly of the mold, the rear faces of the back-up members having inclined grooves therein, a locking block located at the bottom end of said inclined grooves, and a clamping means comprising a main body member, two opposed arms extending from the front portion of the main body member, the ends of said opposed arms being located in the inclined grooves on the rear faces of the back-up members in a sliding clamp relationship and a handle for manipulation secured to the rear portion of the main body member. f

References Cited in the le of this patent UNITED STATES PATENTS 433,079 Halsey et al July 29, 1890 1,715,418 Langenberg June 4, 1929 1,749,314 Carbis Mar. 4, 1930 1,950,354 De Bats Mar. 6, 1934 1,973,550 Todt Sept. 11, 1934 2,295,858 McWane Sept. 15, 1942 2,332,956 Washton Oct. 26, 1943 2,345,493 Muller Mar. 28, 1944 2,479,191 Williams et al Aug. 16, 1949 2,541,923 Huxham Feb. 13, 1951 2,767,449 Tueth Oct. 23, 1953 FOREIGN PATENTS 510,365 Germany Oct. 18, 1930 683,330 Great Britain Nov. 26, 1952 1,071,386 France Max'. 3, 1954

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