US3404726A

US3404726A - Ram-up chill and chaplet studs

Info

Publication number: US3404726A
Application number: US517673A
Authority: US
Inventors: Walter P Wittke
Original assignee: Nasco Inc
Current assignee: Nasco Inc
Priority date: 1965-12-30
Filing date: 1965-12-30
Publication date: 1968-10-08
Anticipated expiration: 1985-10-08

Description

Oct. 8, 1968 w. P. WITTKE 3,404,726

RAM-UP CHILL AND CHAPLET STUDS Filed Deo. 30. 1965 Qfromsyf" United States Patent O 3,404,726 RAM-UP CHILL AND CHAPLET STUDS Walter P. Wittke, Rockford, Ill., assignor to Nasco, Inc., Rockford, Ill., a corporation of Illinois Filed Dec. 30, 1965, Ser. No. 517,673 7 Claims. (Cl. 164-357) This invention relates to studs used in molds having cavities for receiving molten material to be cast and, more particularly, to the stud heads which are disposed within the packed material forming the mold to hold the stems of the studs in the desired positions in the mold. The invention is particularly concerned with the heads of so-called chills which are disposed in larger zones of the mold cavity to carry away the heat of molten metal and accelerate the cooling in the larger zones, but also is applicable to chaplets for holding a loose core in place in the cavity as the molten material ows into the cavity around the core.

The general object of the present invention s to provide a new and improved head construction which, as compared to prior constructions, is more quickly and easily positioned in the mold material and provides better anchoring of the stud in the mold.

Another object is to provide an improved ram-up stud, that is, a stud having a head around which the mold material is packed during forming of the mold, which insures that the mold material is packed in holding engagement with all the exposed surfaces of the head.

A further object is to facilitate the removal of the head from the stem when the latter is embedded in the completed casting.

Still another object is to produce the improved ramup stud at a cost less than the cost of prior ram-up studs.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 isa fragmentary cross-sectional view showing a cast part in a mold cavity provided with illustrative chill and chaplet studs embodying t-he novel features of the present invention.

FIG. 2 is a fragmentary cross-sectional view of a pattern having the shape of the cast part in FIG. 1 and used to form the mold with the lstuds therein.

FIG. 3 is .an enlarged perspective view of a chill.

FIG. 4 is an enlarged fragmentary perspective view of a chaplet.

FIG. 5 is an enlarged fragmentary cross-section through the mold and the pattern showing the chill in side elevation.

FIG. `6 is a view similar to FIG. 5 showing the mold and the chill in section after removal of the pattern.

As shown in the drawings for purposes of illustration, the invention is embodied in a chill 10 and two chaplets 11 and 12 as used in a conventional mold which includes a cope 13 and a drag 14 having walls 15 and 17 dening a cavity. Molten metal is introduced into the cavity through a gate 18 and suitable risers (not shown) which are employed as needed. The metal shrinks as it 'solidies to form the cast part 19, and additional Imetal flows into the cavity through the gate to make up for this shrinkage. In some instances, however, narrow sections of the metal such as the section 20 in the gate passage tend to solidify before a larger central section and thereby prevent further ow of metal to the larger section. This can result in defects in the casting.

To prevent such defects from forming, the chilll10 is inserted in the larger section to absorb heat from the molten metal and cause this metal to cool and shrink before the smalle-1' section at 20 solidies. Such chills have a stem 21 which is disposed in the mold cavity, and

Cil

3,404,726 Patented Oct. 8, 1968 ice a head which is embedded in one wall of the mold to support the chill in the desired location in the cavity. The chaplets 11 and 12 are generally similar to the chill in construction and mounting but are used as positioning elements supported on the walls of the mold and engaging a core 22 positioned in the cavity to form a recess at 23 in the casting 19. The chaplets hold the core in place as the molten metal liows into the cavity around the core. Herein, the chaplet 11 is shown with its head embedded in the side wall 17 of the cavity and its stem 24 engaging the adjacent side of the core to hold the latter against lateral shifting. The head of the other chaplet 12 is embedded in the top wall 15 of the cavity and with the stem 25 thereof engaging the top of the core.

The primary structural difference between the chills and chaplets shown is in the stems. To effect rapid heat transfer and fusing of the heat transfer surface with the molten metal, the stem 21 of the chill 10 is knurled or serrated for increased surface area as compared to a cylindrical stem. Since the important function of the chaplets is the holding of the core, the

stems

24 and 25 may be simply cylindrical pins. It will be seen in FIG. 1 that the stems of both types of studs remain in the casting 19 and become integral parts thereof after the mold is removed. The heads of the studs project out of the casting and are broken off at the surface of the latter.

The present invention contemplates a new and improved construction of heads for studs of the foregoing character, the improved heads more quickly and easily embedded in the mold material in precisely the position desired and providing better anchoring of the studs after the heads are embedded in the Walls of the mold. To these ends, each head comprises at least one section 27 of wedge-shaped or generally triangular longitudinal crosssection tapering toward the adjacent end of the stem of the stud and joined at its smaller end 2S to the stem. With this arrangement, the material used to form the mold parts may be rammed around the head in tightly packed holding engagement with the exposed surfaces of the head to anchor the stud securely in place as an incident to the forming ofthe mold.

In this instance, the head of the chill 10 comprises two conical sections 27 coaxial with each other and with the stem and having a maximum diameter at the larger end of each section preferably the same as the outside diameter of the stem 21. The smaller end 28 of the first section is integrally joined to the upper end of the stem, and the smaller end 29 of the second section is joined to the larger end 30 of the rst section. While the degree of taper is not critical, I prefer a taper on the order of thirty degrees with the axis of the stud.

To form the mold with the chill 10 in place, the stem 21 of the chill is inserted in a closed bore 31 in a pattern 32 (FIG. 2) having the shape of the cavity 19 to be formed. The bore is formed in the pattern in the location corresponding to the desired location of the chill, and its length is selected to hold the outer end of the stem 21 substantially -ush with the outer surface of the pattern. When molding sand is packed around the pattern and the protruding head sections 27 of the chill (see FIG. 5), the granular sand can ow around the head sections and become firmly packed against the tapered side surfaces of the sections. Then, when the pattern is removed, the chill is suspended from the top wall 15 of the mold as shown in FIG. 6.

Studs that are installed in this manner are called ramup studs in the art, in view of the ramming and packing of lthe sand around the heads. In prior ram-up studs, however, the heads have been flat plates or the like fastened as by rivets to the stems, and the substantially perpendicular overhangs of such heads have prevented lirm packing of sand under the heads.

Although the maximum diameter of the head sections 27 may be no greater than the outside diameter of the stem 21, a plurality of such sections with tapered side surfaces provide a holding surface area equal to or greater than the area provided by flat heads. Moreover, the new stud can be manufactured more economically than studs with riveted heads because of the one-piece construction that can be turned out in quantity using bar stock and an automatic screw machine. Further, the narrowness at the line of joinder at 28 between the head and the stern is a convenient break-off point facilitating removal of the head from the completed casting 19. This break-off point is formed automatically as an incident to the shaping of the head.

As will be seen in FIG. 2, the illustrative chaplets 11 and 12 are installed in the same way, using bores 33 and 34 in the pattern 32 at the desired location of the stems of the chaplets, and packing the sand around the heads in firm holding engagement therewith. The packed sand cooperates with the tapered sides of the head sections 27 to initially hold the chaplets in place relative to the mold parts, and the flats 30 forming the larger ends of the sections cooperate with the sand in holding the chaplets against movement deeper into the sand. These flats preferably are perpendicular to the longitudinal axes of the chaplets. A cylindrical section 35 (FIGS. 1-3) may be formed at the end of each chaplet stem to join the first conical section 27 to the

stem

24, 25 while providing a stop for abutting against the outside of the pattern 32 as shown in FIG. 2. Of course, the flat outer surface 37 of this section bears against the packed sand to assist in holding the head against movement into the sand.

In selecting the number of head sections 27 to be used on a particular stud, `consideration is given to the weight of the stud to be supported on the mold and the surface area necessary to prevent movement of the stud. It is a very simple matter to add or remove head sections in making up the studs.

I claim as my invention:

1. In a mold having walls composed of packed granular material defining a cavity for receiving molten material to be cast, the combination with said mold of a stud having a stem projecting into said cavity from one of said walls, and a head joined to one end of said stem and disposed in the packed material forming said one wall, said head having at least one section of triangular longitudinal cross-section tapering toward and joined to said one end with said granular material packed around the head in holding engagement with all exposed surfaces of said section.

2. The combination defined in claim 1 in which said head comprises a plurality of generally conical sections coaxial with each other and with said stem and each tapering toward the stem, said sections and said stem being integrally joined together.

3. In combination with a mold having a cavity for receiving molten material to be cast, a stud having a stem for projecting into said cavity from a wall of said mold, and a head on one end of said stem adapted to be packed in the material forming said wall, said head having at least one section of wedge-shaped longitudinal cross-section tapering toward and joined to said one end to facilitate packing of the mold material around the head to hold the latter in the mold.

4. For use with a mold having a cavity for receiving molten material to be cast, a stud having a stem for projecting into said cavity from a wall of said mold, and a head on one end of said stem adapted to be packed in the material forming said wall, said head having at least one section of wedge-shaped longitudinal cross-section tapering toward and joined to said one end to facilitate packing of the mold material around the head to hold the latter in the mold, said stud further including a second similar section tapering toward said stem and having a substantially flat surface facing away from said stem, said second section being joined at its smaller end to the larger end of said one section.

5. A stud as defined in claim 4 in which said sections are conically shaped and coaxial with each other and with said stem.

6. A stud as defined in claim 5 in which said stem is generally cylindrical and the maximum diameter of said sections is approximately the same as the diameter of the stem.

7. A stud as defined in claim 5 in which said head includes a cylindrical section larger than said stem joined to said one end between the latter and the first conical section.

References Cited UNITED STATES PATENTS 1,924,280 8/1933 Hobart 164-399 1,945,358 1/1934 Raible 164-399 2,170,103 8/1939 Westover 164-357 X FOREIGN PATENTS 56,801 7/1912 Austria. 300,452 9/1932 Italy.

T. SPENCER OVERHOLSER, Prlmu'y Examiner.

E. MAR, Assistant Examiner.

Claims

1. IN A MOLD HAVING WALLS COMPOSED OF PACKED GRANULAR MATERIAL DEFINING A CAVITY FOR RECEIVING MOLTEN MATERIAL TO BE CAST, THE COMBINATION WITH SAID MOLD OF A STUD HAVING A STEM PROJECTING INTO SAIDCAVITY FROM ONE OF SAID WALLS, AND A HEAD JOINED TO ONE END OF SAID STEM AND DISPOSED IN THE PACKED MATERIAL FORMING SAID ONE WALL, SAID HEAD HAVING AT LEAST ONE SECTION OF TRIANGULAR LONGITUDINAL CROSS-SECTION TAPERING TOWARD AND JOINED TO SAID ONE END WITH SAID GRANULAR MATERIAL PACKED AROUND THE HEAD IN HOLDING ENGAGEMENT WITH ALL EXPOSED SURFACES OF SAID SECTION.