US2719327A

US2719327A - Centrifugal casting processes and apparatus for casting true paraboloidal convex surface patterns

Info

Publication number: US2719327A
Application number: US216367A
Authority: US
Inventors: Pique Baudilio Jesus
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-03-19
Filing date: 1951-03-19
Publication date: 1955-10-04
Anticipated expiration: 1972-10-04

Description

2,719,327 CENTRIFUGAL CASTING PROCESSES AND APPARATUS FOR CASTING Oct. 4, 1955 B. J. PIQUEI TRUE PARABOLDIDAL CONVEX SURFACE PATTERNS Filed Mqrvh 19 1951 Fie.2

INVENTOR United States PatentO My invention relates to improvements in centrifugal casting processes and apparatus for casting true paraboloidal convex surface patterns. It has been designed more particularly as a device for making feasible the construction of parts that are combined in my invention described and claimed inthe continuing application Serial Number 450,982 (filed August 19, 1954, for Negative Pattern and Hollow Mold for Casting Compound Reflector Members, which is a device for making commercially practicable thejadaptation 'of the complementary parts combined in my invention disclosed and claimed in the United States Letters Patent Number 2501,1 issued March 21, 1950 for Electric-Light Projecting Reflector.

It is known that the best concave surface produced with extreme accuracy is the paraboloid of revolution, because when a liquid body is contained in a receptacle which rotates uniformly, the surface of the liquid takes the form of an accurate paraboloid. The natural surface of liquids in an absolute or relative state of repose are extremely accurate. When this liquid consists of a solid in fused condition, and is cooled while continuing at the same angular velocity, the liquid body will solidify,

conserving the paraboloidal surface.

When two bodies having different physical conditions, referring to their specific weights and fusion points, are contained in fused condition within a receptacle, the

heavier liquid will be under the lighter liquid. When these liquids are in absolute or relative state of repose, the liquid joint surface will have equal shape than the top liquid surface. When these two liquids are contained in a receptacle which rotates uniformly, the top liquid surface and the liquid joint surface take equal forms of accurate paraboloid. If the receptacle continue at the same angular velocity while the liquids are cooling, these liquid bodies will solidify comprising paraboloidal surfaces accurately formed.

One of the advantages of such casting process is to produce negative pattern having true paraboloidal convex surface.

As wrought concave and convex surfaces are not as accurate as is desired for patterns, one of the objects of my improvement is to form negative patterns having true half paraboloidal convex surfaces.

A further object of my improvement is the provision of an apparatus comprising a receptacle that rotates uniformly having means for holding determinate quantities of two melted materials, according to the angular velocity applied to said receptacle. These melted materials having ditferent physical conditions with each other, referring their specific weights and fusion points, will form separable composite casting.

Another object of my improvement in connection with such centrifugal casting apparatus, is the process with two melted materials for making couple of half paraboloidal convex patterns, which process comprises to regulate alternately the amount of said two melted materials to be conformed in said centrifugal casting apparatus. One of said melted material will be adjusted as part of mold in connection with said apparatus and the other one melted material will be conformed for easting to obtain said couple of half paraboloidal'convex patterns.

Another object of my improvement is to provide'means in a centrifugal casting apparatus for making with two melted materials couple of half patterns having an inner plane border limiting half convexparaboloid and a bevel border of uniform thickness at their peripheries. The apparatus may be so operated in a centrifugal casting process that each couple of half patterns cast in the apparatus will have a different convex curvature from every other couple cast in the same apparatus and having the same thickness of bevel border at their peripheries.

Other objects and advantages of my invention will appear from the following description with reference to the accompanying drawings, in which: Fig. l is a vertical sectional view of an appropriate apparatus for centrifugal casting, showing the improvements; Fig. 2 is a sectional view of a hollow mold showing the object attained with this invention; and Fig. 3 is a sectional View through the line 33 of Fig. 1. Similar numerals refer to the same or similar parts through the figures.

Referring to Fig. l and Fig. 3, my invention comprises:

An apparatus for centrifugal casting comprisinga receptacle A having a curved base 1 with the inner side forming a rippled paraboloidal surface 2. Said receptacle A is provided with a cylindrical end 4 having a conical edge at the periphery thereof.

A thin blade 9 having a paraboloidal border is fitted and attached by its border on the inner paraboloidal rippled surface 2 of said receptacle A.

A rotor axle 3 attached to the receptacle A, is placed vertically in a machine not shown in the drawings, which rotates uniformly together with the receptacle A around its symmetrical axis.

A melted material 10 is put within the receptacle A to be adapted as part of mold, which will be adjusted in connection with said receptacle A according to the angular velocity in the process of centrifugal casting.

A conical ring 5 having an inner sharp edge 6, is as sembled with said cylindrical end 4 at theperiphery of receptacle A, it being fitted by means of a ring flange 7.

Another melted material 11, having lighter specific weight and higher fusion point than the first one, is put within the receptacle A for casting couple of half paraboloidal convex patterns 11-11 upon said first melted material 10.

The cylindrical end 4 with its conical edge is adapted at the periphery of receptacle A to regulate the amount of the first melted material 10. The conical ring 5 with its inner sharp edge 6 is adapted upon the cylindrical end 4 of receptacle A to regulate the amount of the second melted material 11 and to form a bevel border 14 at the peripheries of casting patterns. And, the thin blade 9 is adapted in the receptacle A to disjoint halves of said casting pattern 11 through a plane holding the axis of paraboloidal surface 12, and for forming an inner plane border 9' in the casting pattern 11 limiting half convex paraboloid 12 and thus obtaining a couple of half patterns 1111.

An annular pan 8 is located separately surrounding the rotor receptacle A.

The process with two melted materials for making couple of half paraboloidal convex patterns, in connection with this centrifugal casting apparatus, is as follows:

When the receptacle A, without the conical ring 5, rotates with a predeterminate velocity having within it the melted material 10, the material will flow upward by centrifugal force and its top surface takes the paraboloidal shape 12 with a concave curvature according to the angular velocity applied to said receptacle A. This happens after the excess of liquid mass 10 is spilled out of the cylindrical end 4 by centrifugal force to the annular pan 8, and an appropriate quantity of said melted material 1 is retained by said cylindrical end 4 to be adjusted as part of mold in connection with said receptacle A.

After this, fitting the conical ring 5 upon the cylindrical end 4 of receptacle A, and then, when said receptacle A rotates with the same predeterminate velocity, the other melted material 11 from which half paraboloidal convex patterns will be formed, is put within the receptacle A and upon the first material 10, whence, the second melted material 11 flow upward by centrifugal force, the excess of this material 11 will be spilled out from inner sharp edge 6 of conical ring 5 to the annular pan 8, and an appropriate quantity of said material 11 is retained by said conical ring 5 to be conformed for casting. The liquid joint surface 12 will be a predeterminate true paraboloidal surface as same as the top liquid surface 12'. Furthermore, the thin blade 9 will form in the half patterns an inner plane border 9' limiting half convex paraboloid 12, and the conical ring 5 will form a bevel border 14 of uniform thickness at the peripheries of half patterns 11.

When the

materials

10 and 11 are cooled by lowering their temperature between the temperatures of fusion points of both

materials

10 and 11, the material 11 having higher fusion point than the material 10, will be solidified, and the material 10 will continue melted, forming separable composite casting. In this condition, after take out the conical ring 5, the solidified material 11 may be taken out by a suction cup.

Making another couple of half patterns 1111', by

distinct angular velocity of receptacle A than that of the firstpatterns 1111, it after have been corrected the quantity of the first material 10 according to the angular velocity applied to the receptacle A in accordance with the curvature required in such couple of half patterns 11'11.

Each different couple of half patterns 11-11 and 11'11, will have different

paraboloidal convex curvatures

12 and 13, and with the same uniform thickness of bevel border 14 at their peripheries, it shaped by the conical ring 5, and an inner plane border 9 limiting

half paraboloids

12 and 13, it shaped by the thin blade 9.

Two

different half patterns

11 and 11, taken from two different couples of half patterns, may be joined and welded together through their inner plane border 9 as is shown in Fig. 2, to constitute a negative pattern having half

convex paraboloids

12 and 13 with different convex curvature and displaced from each other along the paraboloidal axis but their peripherical bevel border 14 coinciding in ring section.

This negative pattern 1111', which comprises true half paraboloidal convex surfaces 12-13, may be used as compound surface pattern in pressing apparatus or in hollow mold as is shown in Fig. 2.

A plate base having a bevel ring support 15 to adjust the compound negative pattern 1111' throughout its peripherical bevel border 14. And a cover member 16 having an inner paraboloidal concave surface 17, is adapted on said bevel ring support 15, closing said negative pattern 1111 in a hollow mold 19. The cover member 16 have a hole 18 communicating the hollow mold 19 with the exterior. 1

This hollow mold 19, Fig. 2, is formed among the concave paraboloidal surface 17 and both

half convex paraboloids

12 and 13 having different curvature with each other, and ending the hollow mold 19 on the bevel ring support 15. The casting is made through the hole 18 into the hollow mold 19 for making paraboloidal reflectors comprising half paraboloidal concave surfaces 1213 with different concave curvature and displaced from each other along the paraboloidal axis, and having their peripheries coinciding in conical ring section.

I claim:

An apparatus for centrifugal casting comprising a receptacle having an inner paraboloidal rippled surface and being adapted to rotate uniformly around its symmetrical axis, the said receptacle being provided with a cylindrical end at the periphery thereof, a conical ring having an inner sharp edge assembled with said cylindrical end and a thin blade having a paraboloidal border fitted and attached on the inner paraboloidal rippled surface of said receptacle.

References Cited in the file of this patent UNITED STATES PATENTS 323,896 Stock Aug. 4, 1885 669,119 Krank Mar. 5, 1901 1,367,507 Clark Apr. 20, 1915 1,341,670 Powell June 1, 1920 1,545,455 Radford et al. July 7, 1925 l,831,310 Lindemuth Nov. 10, 1931 2,221,695 Robertson Nov. 12, 1940 2,400,482 Brannon et al. May 21, 1946 2,448,492 Mayne Aug. 31, 1948 2,671,932 Pique Mar. 16, 1954