US2811253A - Extrusion presses - Google Patents

Description

1957 w. SCHIEREN 2,811,253

EXTRUSION PRESSES I Filed April 4, 1955 United States PatetitC)" nxTRUsIoN PRESSES WilhelmSchieren, Duisburg,Germany, assignor to 'Schloemann Aktiengesellschaft, Dusseldorf, Germany Application April 4,1955," Serial No. 499,108

Claims priority,-application- Germany'April 12', 1954 5 Claims. (Cl. 207-5) in extruding blocks of lead, aluminium or their alloys provision must be made for the air present between the block and the receiver wall to escape backwards and not to get into the extruded product or rod. It is known for this purpose to temper the block at the side facing of the press plunger lower than the side facing the outflow aperture.

Furthermore, it is sought to hold back oxide and dirt particles adhering to the peripheral surface of the block from flowing out into the rod, so that they will collect in the block residue which can be removed after the pressing operation.

The aforesaid objects are assisted, as experiments have shown, by the expedient, that the receiver bottom containing an outlet aperture is provided with a ridge projecting between the receiver wall and the outlet aperture into the receiver, which ridge is preferably arranged so as to be concentric with the cylinder. Such a ridge is suitable for use both with double block presses and simple presses.

When the invention is applied to an extrusion press provided with a cavity tool arranged in the direction of the plunger axis, the annular ridge is preferably formed on an annular disc disposed in the receiver and bearing against the cavity tool.

During the application of pressure the dirt and oxide particles collect in the press residue which forms alongside the ridges, whilst the interior of the block flows away undisturbed.

As the aforesaid experiments have also shown, the arrangement according to the invention also helps to causethe block to flow more freely at the end lying towards the outflow side. This is presumably to be attributed to the penetration of the ridge into the block and has the special advantage, that the block becomes compressed sooner at the end lying towards the outflow aperture than at the opposite end. Through this the block is first brought to bear at the end lying towards the outlet side against the receiver wall, so that the air present between the block and the receiver wall is displaced in the opposite direction to the pressing direction.

The more ready flow can also be assisted, if the inner opening of the annular disc be made to widen in a wedgeshaped or conical manner in opposition to the direction in which pressure is applied. This conical widening is also of advantage, when the wedge like or conical formation of the opening causes the channel openings of the cavity to be partially closed by the annular disc bearing the ridge.

The ridges and the wedge like or conical formation of the outlet aperture according to the invention may alternatively be provided directly on the cavity tool itself. It is preferable however to arrange them on the annular disc forming a separate piece, as such a simply made annular disc can be easily exchanged and can thus be adapted in each case to the material which is to be extruded.

The invention is illustrated in the accompanying drawing in which:

Figure 1 shows tools of an extrusion press according to the invention in section on the line 1-..1 in Figure 2, uring the extrusion operation;

Fig re 2.. is a sec i n Minnelli-II of Figure 1; and

Figure 3' the same section as Figure, 1 at the end' of the. extrusion operation.

Thereceiver I bearsi'n" a' manner known per se against a cavity tool 2, in which is'a. matrix 3whichfbe'ars against a holding-up member 4. Indie cavity tool'fivecha'nnels 5 are provided which open into an annular space 6. The

material between the channels 5 supports a mandrel 7, the end 7a of which together with the matrix 3 forms the annular gap for the production of a tube 8. The material 9 is forced out in a manner known per se by a press plunger 10 with a press disc 11.

According to the invention there is provided in the receiver 1 an annular disc 12 which is provided with an annular ridge 12a. This annular ridge is preferably of triangular pointed cross-section, the point of which is op positely directed to the pressure-applying direction. The inner opening 12b is immediately adjacent to the annular ridge and is tapered conically in the pressure-applying direction, so that the material 9 is compressed as it enters the inner opening, which has a favourable effect on the internal structure of the material of the block. As will be seen from Figure 2, the annular disc 12 partially closes the channels 5 which are of circular crosssection. The annular ridge 12a causes, as the above experiments have shown, the block material 9 to flow more rapidly, namely at that side which faces the annular disc 12. Consequently, as the press plunger 10 commences to work, the material will first be caused to bear against the receiver wall in the region of the annular disc 12, whilst that part of the block which faces the press disc 11, will come against the receiver wall later. The air trapped between the block and the wall of the receiver 1 will therefore be displaced towards the right out of the receiver and emerges in the region of the press disc 11.

As the press plunger 10 continues its forward motion, the block will flow out mainly out of its middle portion. Those parts of the block which are in the vicinity of the receiver wall are, however, pushed forward in the direction of the receiver wall and will, therefore, accumulate in the space next to the ridge 12a. When the pressing operation is ended, a position as shown in Figure 3 is reached, in which the press disc 11' bears against the ridge 12a or nearly does so. In the residue 9a of the pressed material, which is completely or almost completely separated from the rest of the pressed material 9b, those portions of the original block will have accumulated, which were in contact with the receiver wall, so that the major part of the dirt and oxide particles which adhered to the original block will be in the residue 9a of the pressed material. The annular disc 12 can be ejected, whereupon the residue 9a can be easily removed. The annular disc 12 can be differently formed to suit the material to be dealt with. This different formation applies to the conical angle of the wall 12b, the height of the ridge 12a, the amount by which the annular disc 12 covers the channels 5 to a greater or less extent, to the distance of the ridge from the opening 12b and to the crosssectional form of the ridge. It is possible to form the ridge 12a directly on the cavity tool 2.

I claim:

1. A press for the extrusion of billets of lead,-aluminium and other metals, comprising: a receiver, a press plunger slidable in the bore of the receiver, a cavity tool closing the front of the receiver, the said cavity tool being formed with an annular cavity, a mandrel connected fast with the said cavity tool and extending through the said annular cavity, the cavity tool being formed with passages through which the material that is being extruded can pass from the receiver to the annular cavity, a matrix,

Pat nted -OCL. 129,; 1957 closing the front of the said annular cavity, for shaping the material passing through it, and an annular ridge at the rear end of the cavity tool, facing the receiver, and surrounding the rear ends of the passages extending through the cavity tool. 7 7 a 2. An extrusion press as claimed in claim 1', the annular ridge being co-axial with the bore of the receiver.

3. An extrusion press as claimed in claim 1, further comprising anannular disc located in the front end of the receiver and hearing against the rear end of the cavity tool, the annular ridge being formed on the said annular disc.

4. An extrusion press as claimed in claim 3, the inter- 5 lar ridge being of triangular cross section.

References Cited in the file of this patent UNITED STATES PATENTS Hansen May 14, 1846 2,753,044 Haendeler July 3, 1956 FOREIGN PATENTS 715,411 Germany Dec. 20, 1941

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