US2034692A - Apparatus for making centrifugal castings - Google Patents

Description

March 24, 1936. H. BREITBART APPARATUS FOR MAKING CENTRIFUGA L CASTINGS Filed Dec. 1' 1954 Patented Mar. 24, 1936 NIT STATES APPARATUS FOR MAKING OENTRIFUGAL CASTINGS Hans Breitbart, Duisburg-Beech, Ge

'1 Claims. (CL 22-65) The present invention relates to a process for whereby the increasing of the thickness of the l layer of casting material formingthe casting body is positively controlled directly at and by the inner wall of the centrifugal mould during the centrifugal action. Thereby undesired spreading of the liquid casting material and formation of blow holes is positively avoided and a calm operation and a. homogeneous casting is obtained.

Another object of the present invention resides in the provision of a process and apparatus in which the thickness of the layer of the casting material is controlled more especially by a distinct control of the .distance of a barrage body from the inner wall of the centrifugal mould during the whole of the centrifugal operation and not only after the casting body has been formed in order to obtain a final compressing and smoothing action, as is done with conventional processes.

A further object of the present invention consists in the provision of a new process and apparatus in which the casting material is conveniently fed into the centrifugal mould at the side of a barrage body parallel to the centrifugal mould, which side is directed towards the descending wall of the centrifugal mould.

An object of the new process consists in influencing the casting material so thatit is absolutely evenly distributed over the mould immediately at that spot where the final forming takes place. Thereby greatest possible homogeneity and evenness of distribution are ensured.

The building-up operation by means of the barrage body directly at the forming wall represents a. positive mechanical action upon the casting material, whereby formation of waves in the building-up material or impurities, which may still be present therein, cannot harm the casting operation, because the casting material arriving onthe side of the barrage where the casting is actually produced, as to its quantity and quality; is in proportion to the progress of the building-up operation.

With the new process, the casting material may be chargedin a manner known per se, either directly in a quantity suilicient for producing the cast body or from a distributor'which is introduced into the mould.

The device for carrying out the new process is particularly distinguished by its simplicity. According to the invention, it is sumcient for cfiecting the building-up to construct the barrage body as a fiat wall arranged close to the forming wall. Obviously. means are to be provided for raising or lowering the wall in order to change its distance from the inner wall of the mould.

The barrage body, however, may be constructed in known manner as a roller. In this case, the degree of the building-up may also be controlled by varying the speed of rotation of the roller; The same effect can be obtained by varying the distance of the roller from the wall of the mould.

Instead of a. barrage body formed as a roller, a fiat barrage wall may be used which has the advantages that a wall is not only .cheaper and easier to manufacture and to arrange than a roller with the same efiect, but also that the handling of a. device provided with a wall as barrage body is much simpler than that of one with a. roller-shaped barrage body. The lighter wall may be lifted with less consumption of energy than is required by a roller. In special cases, a

mere tilting of the wall may suffice to increase the distance of the lower edge of the barrage body from the inner wall of the mould, which is obviously impossible with a roller. Further, the forming, lower edge of the barrage wall can be kept in good working condition with less trouble than is required bythe cylindrical surface of a barrage roller. A further advantage of arranging a barrage wall instead of a barrage roller consists therein that the former requires much less space than the latter for the same thickness to be built up.

The barrage body may also be made hollow for the reception of a, cooling agent.

According to another feature of the invention, the barrage wall may also be shaped so that its lower side is at a distance from the inner wall of the mould which varies at difierent points distributed over the length of the mould. Also, the lower side or edge of the barrage wall may be provided with a series of notches or lugs to form a comb-like edge in order to produce castings having different inner diameters at different points of their lengths or to divide the casting material into several strips.

According to a further feature of the present invention, the barrage wall may also be constructed as a trough having an opening at one end ior the reception of the casting material to to the wall of the mould.

Fmther and other objects of the present inven- '66 be red 2 tion will be hereinafter set forth in the accompanying specification and claims and shown in the drawing which, by way of illustration, shows what I now consider to be a preferred embodiment of my invention.

In the drawing:

Fig. 1 diagrammatically shows a cross section through a centrifugal mould having a barrage body formed like a plate.

Fig. 2 is a cross section through a centrifugal mould which is charged through a distributor positioned within the mould.

Fig. 3 diagrammatically represents a further form of construction with a barrage body shaped as a roller.

Fig. 4 perspectively shows a barrage body constructed as a trough for reception of the casting material.

Fig. 5 is a perspective view of a barrage wall, the lower edge of which is shaped like a comb.

Fig. 6 is a large size cross sectional view of a modified barrage construction according to the present. invention.

- In the interior of the casting mould I provided with a lining 2, according to Fig. l, a barrage body 3 is arranged in the vertical plane of the axis of the mould, which body is shaped like a plate.

A slot 4 is left between the lower edge of the barrage body 3 and the inner wall of the mould I contacted by the casting material. The width of the slot can be varied by a parallel displacement of the barrage body or by rocking the body about an axis eccentric to the axis of the mould. Mechanical devices for carrying out such displacement or rocking motion are shown in Fig. 4.

The length of 'the barrage body corresponds to 3 the length of the mould. The lower edge of the barrage body is preferably rounded and, according to Fig. 5, may be provided with notches 23 or with tapered projections 24, 25 to divide the liquid casting material into strips. For producing castings of different internal diameter, the lower edge of the barrage body may be provided with suitably shaped recesses.

Those parts of the barrage body which come into direct contact with the molten casting material may be protected by a heat resisting material such as quartz, clay, graphite, carbon, high temperature resisting metals or alloys. This may be inserted in the form of rods I! having cylindrical, oval or prismatc cross section into recesses l8 provided on the parts of the surfaces of the barrage bodywhichare. particularly exposed, as is shown in detail in Fig. 6. Or it may cover the surface only and be placed in grooves, as is shown in Fig. 1. The heat resisting material may also consist of flat bodies I9 as are shown in Fig. 2.

In the construction shown in Fig. 2, the mould I is provided with a hollow space 5 for the reception of a cooling agent. The barrage body 3 is also provided with a hollow space 6 for the reception of a cooling medium; The mould l is charged by means of a distributor 1 arranged within the mould and which is tiltable about ,trunnions' 8 for discharging purposes.

The barrage body 3 of the device represented in Fig. 3 has the form of a roller which may be operated by means of a speed changing mechanism 20 which is driven by a motor 2|. Instead of using the independent motor 2|, the speed changing gear may be driven by motor 22 rotatirg the mould l, or a variable speed motor may be used instead of gear 20.

Another form of construction of a barrage body by the arrow l2.

is perspectively represented in Fig. 4. The barrage body has the form of a trough I3 with part or all of the bottom removed so that the lower edges of the side walls serve, in cooperation. with 'the inner wall 2 of the mould, to define the thickness of the casting. For charging the trough which, in this case, constitutes the barrage body, a distributor having the form of a pipe or gutter is used. This gutter or pipe 1 may be moved forwards and backwards within the mould during the casting operation in a direction axial with respect to the mould, whereby the distribu-' tion of the casting material over the whole length of the mould can be controlled.

It is obvious that, with this form of construction, the width of the slot between the lower edges of the walls of the barrage body and the inner wall of the mould can be adjusted by rocking the barrage body about its supporting rod M orby its displacement within a verticalplane.

As is clearly obvious from Figs. 1 to 3, spaces 9 and ID are formed within the lower part of the mould by arranging the barrage body 3. casting material II is fed into the space 9 which is in front of the barrage body when seen in the direction of rotation of the mould-represented The journals and driving devices of the barrage body which are not particularly shown are outside of the mould l. The distributor 1 extends over the whole length of mould I.

The devices operate as follows:

The casting material is fed either directly into the mould lFig. 1--or into the distributor 1- Figs. 2 and 3or 1-Fig. 4. In the first case, mould i may stand still during the charging operation or may be slowly rotated.

As soon as the mould contains the whole charge sufficient for the production of the casting, or also after the mould is only partially charged, the mould is rotated at full speed in the direction of arrow l2. Then the casting material built up by the barrage body 3 withinthe space 9 passes through the slot 4 into the space [0, whereby all noxious influences of the formation of waves are eliminated. During the rotation of the mould, the barrage body 3 is raised corresponding to the The falling of the level of the casting material in space 9, or barrage body 3 is so turned that the width of slot 4 is increased corresponding to the increase of the layer of the casting material lying against the inner wall of the mould. Such operation of thebarrage body may-be accomplished by a worm arrangement outside of the mould, as is designated by numeral I5 in Fig. 4. The tuming or tilting of the barrage body could be done, for example, by manipulating the wheel IS on shaft l4. Towards the end of the centrifugal operation, a smoothing effect may be exerted upon the innermost layer of the casting material by the rounded lower edge of barrage body' 3, whereupon the barrage body is brought out of contact with the casting material.

With the devices according to Figs. 2 and 3, the

Fig. 4the casting material is fed into the trough by means of a distributor having the form of a gutter, pipe or the like which may be progressively displaced in an-axial direction into the mould. Hereby the casting to be produced is formed progressing in the axis of the mould.

While I believe the above described embodiments of my invention to be preferred embodiments I wish it to be understood that I do not desire to be limited to the exact details of process, design and construction shown and described, for obvious modifications will occur to a person skilled in the art.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. The combination, in a centrifugal casting machine, of a rotary mould having an inner wall with a barrage body having the shape of a fiattened wall positioned within said mould and adjustable during the whole of the centrifugal casting operation as to its distance from said inner wall, said body distinctly dividing the interior of said mould into a material receiving and a material applying part, substantially as set forth.

2. The combination, in a centrifugal casting machine, of a rotary mould having an inner wall and of casting material supply means within said mould with a tiltable barrage body which is separate from and independent of said supply means and has an operating surface located within said mould, said body being tiltably adjustable during the whole of the centrifugal casting operation as to the distance of said operating surface from said inner wall, substantially as set forth.

3. In a machine for making centrifugal castings from a liquid casting material, a rotary mould, a barrage body within said mould and having an operating surface, shieldingmeans connected to said surface and contacting with the liquid casting material and protecting said barrage body from the liquid casting material as, and for, the purposes described.

4. In a machine for making centrifugal castings from a liquid casting material, a rotary mould, a barrage body within said mould and having an operating surface, shielding means attached to said surface and contacting with the liquid casting material and protecting said barrage body from the liquid casting material, said barrage body having recesses, and said shielding means consisting of rodshaped bodies fitting into said recesses as, and for, the purposes described.

5. In a machine for making hollow, substantially cylindrical, centrifugal castings from a liquid casting material, a rotary, substantially cylindrical, hollow mould having an inner wall, a barrage body within said mould and having an operating surface contacting with the liquid casting material, said surface having a configuration conforming to the configuration of the interior surface of the castings to be produced and being adjustable during the whole of the centrifugal casting operation as to its distance from said inner wall, substantially as set forth.

6. In a machine for making hollow, substantially cylindrical, centrifugal castings from a liquid casting material, a rotary, substantially cylindrical, hollow mould having an inner wall,

a barrage body within said mould and having an operating edge contact with the liquid casting material, said edge having projections conforming to recessesto be produced on the interior surface of the castings, and being adjustable during the whole of the centrifugal casting operation as to its distance from said inner wall, substantially as set forth.

7. In a machine for making centrifugal castings from a liquid casting material, a rotary mould, a barrage body dividing the interior of said mould into a casting material receiving and a casting forming side, said inner wall of said rotary mould moving from the receiving side towards the forming side when said mould is rotated, and casting material supply means within said mould adapted to discharge liquid casting material into said receiving side, substantially as set forth. 4

HANS BREI'I'BART.

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