US1863935A - Mold for nonferrous castings - Google Patents

Description

June 21, 1932. v.- P. SCHMIDT ET AL MOLD FOR NONFERROUS CASTINGS Filed May 25, 1951 Vic INVENTORS 2:02

WITNESSES Patented June 21, 1932 UNITED STATES P TENT OFFICEIY VICTOR r. SCHMIDT AND HARRYA. nnnnmaiw, or AL'rooNA, PENNSYLVANIA y 7 MOLD ron nonrnnnous CASTINGS Application filed May 23,

This invention relates to molds and more particularly to the art of casting non-ferrous metal compositions, such as piston packing rings, in which there is a relatively high lead or copper content. Heretofore, it has been proposed to cast such mixtures or alloys either in refractory molds, or in molds comprising metal parts associated with sand copes having gates and risers, or in split molds.

m The object of the present invention is to provide a simple, inexpensive and permanent mold for the casting of such compositions, the mold being characterized by the absence of gates or risers and the use of metallic mold I3 and core elements which define an open top cavity within which the casting is formed. The provision of an old metal open top mold dispenses with the usual assortment of molding apparatus for forming gates, risers and 1 passages for the escape of gases and eliminates the waste of metal in cutting off sprues, thus reducing to a minium the amount of metal poured for each casting. Furthermore, it is found that the castings formed in molds qr, constructed in the manner of this invention are more homogeneous and have a denser grain structure.

A further object of this invention is to provide an open top metallic mold formed in one piece to substantially the shape of a tray whereby the mold may be conveniently supported on mold conveying apparatus in a position in whichthe casting composition may be readily poured, and with capacity for tilt- :13 ing while resting in place on the conveying apparatus, so that the mold need not be physically handled during the operation of discharging the castinv therefrom.

Other objects and advantages characterizing our invention will become more fully apparent from the description which follows hereinafter and which has reference to one embodiment or example of the invention illustrated in the accompanying drawing,

whereof:

1931. Serial n 539,426.

' r Fig. I represents a plan View of a mold and 5 core constructed in the manner of our inventioniand,

Fig. II represents a cross section of the same taken as indicated by the lines IIII ofFig.I.' I With reference to' the drawing, it will be is seen that the mold element 1 is substantially square havingslightly curved sides 2pmvid-e'd with two pairs of integral trunnions 3 disposed ata distance above the center of gravity and adapted to serve as pivotal supports by means of whichthe mold maybe tiltably mounted on a conveying apparatus. I Such a conveyor is described in our co-pending application for U. srLetters Patent, Serial No. 539,427, filed May 23, 1931. The provision of asymmetrical mold with alter- Inate pairsoftrunnions enables the mold to be turned to difi'erentpositions within its supporting apparatus, sothat when one set of trunnions wears away a new set may be em :ployed, 'andthe lifeof the mold may thereby be substantially increased. I 4; The body of the mold is in the general shape 0fa tray and comprises an annular central portion 4, terminatingat the top, in an outwardly extending flange 5, and radial ribs 6 joining the bottom of the central portion twith the side edges of the flange 5. Adjacent to the central circular opening 13, the body ofgthe mold is formed with anannular fshouldei, 7 affording an angular recess 8 upon which the cylindrical core 9 is seated. A sloping wall 10 onthe inside of the mold leads, upward and outward'and merges with a vertical cylindrical wallll of a height corresponding substantially to thethickness of the flange 5. These walls 10 and 11 togetherwith the outer wall of the cylindrical core Q definean-annular cavity. whichis filled by the casting. composition 12 andwhichxis open at its. top. Boththe body of the moldl and the core element 9' are preferably made of cast iron. In the example shown in the drawing, the

"with copes having core element 9 is interiorly hollowed and provided with a relatively thin wall. This permits the radiation of heat from the center of the mold to more eflectively chill the cast metal 12.

An example of the composition or mixture which we preferably employ for the casting of piston packing rings is as follows:

Per cent Lead 31 Copper 65' Nickel 3 Sulphur 1 With such a composition or mixture we have foundthat the use of an open topmetallic mold as herein described produces a A homogeneous close-grainedcasting of a quality as good, if not superior, tocastings produced in refractory molds. aware that piston paclrings have been cast heretofore in molds having metal walls and metal cores, such molds have been combined gates -or risers constituting a cumbersome assemblage of parts By dispensing with such elements the operations of pouringoand of discharging the castings are obviously simplified.

Furthermore, the provision of a one piece mold open at the top has obvious advantages over the use of split molds or molds made up of a multiplicity of elements hinged or otherwise assembled together. By seating the removable core 9 in the mold in the manner described, it will be noted that the 7 Casting 12 may be readily removed, with the operation consi'stin-g'of tilting the mold about a pair of trunnions '3, allowing the a casting to fall out, or permitting the casting .tobe tapped out by a blow with'a-ccess to the underside of the core had through :the'opening 13.

' While we have described and illustrated one example or embodiment of our invention,

it will be apparent that various changes may I be "made in the form of the mold and core elements as herein described without departing from the spirit of our invention as de- 'fin'ed in the claim hereto annexed.

' Having thus described our invention, we claim:

A onepiece metallic mold for casting nonferrous rings ofthe character described, said mold having a central circular opening, and a removable-core defining with said mold a cavity having a cylindrical open top, said core seating on an annular shoulder adjacentto said central circular opening 1n the body of said mold.

In testimony whereof, we have hereunto signed our names at Altoona, Pennsylvania, this 19th day of-May, 1931;

jVIo'roR P. SCHMIDT. HARRY A. BRENAM-AN.

While we are

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