US1834996A - Permanent mold - Google Patents

Description

Dec. 8, 1931. A. T. BATEMAN ET AL PERMANENT MOLD Filed Aug. 17, 1928 1 N V EN TOR5 6577x11 77M? 0 fiwdrew lit 0 76 20m 8M A TTORNEY6 Patented Dec. 8, 1931 UNITED m res PATENT OFFICE ARTHUR 1+. BATE AN AND A DREW IRVINE, 013 DETROIT, MICHIGAN, ASSIGNOBS TO BOHN ALUMINUM &- BRAss CORPORATION, or DETROIT, MICHIGAN, A CORPORA- rIoN OFMIGHIG N Application filed August 17, 1928.

The invention relates to permanent molds and has particular reference to permanent molds for usev in casting relatively large annular articles. One of the objects of the invention is to construct the mold that it may be readily operated to secure quantity production with the minimum number of poor castings. Another object is to so construct the mold that it maintains its shape during the operation. Another object is to provide for uniform or substantially uniform heating of the mold. With these as well as other objects in view, the invention resides in the novel features of construction and combinations and arrangements of parts as more V mold, embodying our invention;

Figure 2 is a cross sect-ion on the line 22' of Figure 1;

Figure 3 is a cross section on the line 3-3 of Figure 1.

The permanent mold shown in the present instance has been developed in connection with the casting of relatively large annular articles, such as tub rings, formed of metal, such as aluminum or its alloys having a. high crystallization shrinkage and a low fusing point. This ring is circular and L-shaped in cross section with the radially extending flange 1 terminating in the laterally offset portion 2 and the cylindrical flange 8 formed with the radially offset portions or bosses 1. These bosses are arranged in pairs extending transversely of each other with the bosses of each pair diametrically opposite.

The permanent mold comprises the base 5, the pivotal outer mold sections 6 and the inner mold sections 7, the base and mold sections being formed of metal. The outer mold sections are arranged in pairs with one pair connected to each other by the pivot 8 and the other pair connected to each other by the pivot 9, these pivots being in the nature of pins secured to and extending vertically upward from the base 5. The adjacent free ends of these sections are adapted to be secured together in the casting position of the sections ml by suitable means such as clamps. The inner PERMANENT MOLD Serial No. 300,284.

mold sections 7 are rigidly secured upon the base 5 and provide the annular shoulder 10 which forms a stop for engaging the outer mold sections and locating the same in their casting position. These inner mold sections also cooperate to form the annular tapered shoulder 11 concentric with the annular shoulder 10 and located radially inward and above the same. The inner and outer mold sections cooperate to form an annular upwardly opening mold cavity, the adjacent ends-of the outer mold sections together forming recesses in which the bosses dare formed.

The permanent core is formed of metal sections 12, 13, 1 1 and 15, which are longitudinally arcuate and are channel shaped in cross section with transverse ribs 16 extend ing between the inner and outer walls 17 and 18, respectively, there being partitions at the ends of these sections to close the same. These core sections are insertable by a downward movement into the mold cavity and withdrawable from the mold cavity-by an upward movement and are adapted to cooperate when inserted in the mold cavity to form a sectional annular core. The core sections 12 and 14 are diametrically opposite each other and the end partitions are formed to diverge downwardly. The core sections 13 and 15 are diametrically opposite each other and are located between the ends of the core sections 12 and 141 and the end partitions of these core sections 13 and 15 are formed to converge downwardly and lit the end partitions of the core sections 12 and 14, the core sections 13 and 15 being inserted into the mold cavity after the core sections 12 and 14 have been inserted. The inner andouter walls of these core sections are formed to converge downwardly and to lit the walls formed respectivcly by the inner and outer mold sections 7 and 6. Furthermore, the outer walls 18 of these core sections have the horizontal arcuate shoulders 19 which together form an annular shoulder defining the top of the mold cavity for casting the cylindrical flange 3. Each of these core sections is provided with. a radially offset boss 20 for cooperating with the radially oifset recess formed by the adjacent ends :Of the outer mold sections 6 to form the boss 4. Furthermore, to position the .core sections in the mold cavity, each core section is provided with the radially offset boss 21 above the shoulder'19 and engageable in a correspondingly shaped recess 22 formed in the adj aoent ends of the outer mold sections 6. V

With the above arrangement of sectional permanent mold and sectional permanent core,1the parts maintain their shapes during the operation of the mold, at least'sufiiciently to provide good castings, the thickness of the walls of which will not vary appreciably.

The outer mold sections 6 are provided with passages 23 extending downwardly from their upper faces to the mold cavity, there, beingv in the present instance two pair of these 7 passages at right angles to each other so that either pair may be alternatively used as gates or risers, thereby providing for more un1- formly maintaining the temperature ofthe mold. In other words, first one pair of pas sages are used as gates and the other pair of passages are used asrisers and then the last mentioned pair are used as gates and the first mentioned pair are used as risers so that the heat of the molten metal will be distributed more uniformly throughout the mold. Each of the passages 23 is formed with the downwardly diverging branches 23 arranged to directthe molten metal in opposite directions into the mold cavity, the upper ends of the branches beingbelow the upper end portion of the passage so that the molten metal in this upper end portion exertspressure upon the molten metal in the branches. By reason of this arrangement the mold cavity can beflcompletely filled with molten metal before.

7 it hascooled to-such an extent that itfreezes.

'tudinally centrally of the core sections and The bosses 21 are preferably located longithe tapped hol'es24t for receiving suitable lifting bolts are located preferably in radial alignment with the centers of these bosses, the ribs 16 being enlarged at their inner and.

outer ends to provide the requisite strength.

- What we claim as our invention is:

. r 1. A permanent. mold comprising abase,

afixed permanent inner section'upon'said base having an annular periphery and an upwardly extending annular shoulder spaced inwardly from the periphery, a plurality of l permanenttouter pivotal sections engaging the eri her of said fixed inner section in I theiroperative .position and cooperating with said inner, section to form an upwardly opening recess, a permanent core insertible into said recess and engaging said pivotal sections and the annular shoulder on said fixed inner section and cooperating with said fixed and pivotal sections to define the mold cavity.

2. A permanent mold comprising a base, a fixed permanent inner section upon-said base having an annular periphery and an mg with said fixed and pivotal sections to definethe moldcavity, said core and said pivotal sections also cooperating to define gate means leading to themold cavity.

In testimony whereof we afiix our signatures. I ARTHUR T. BJATEMAN. -ANDREW IRVINE. I

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