US2392190A - Core support for extrusion machines - Google Patents

Description

Jan, 1, 1946. G. RITTER 2,392,190

CORE SUPPORT FOR EXTRUSION MACHINES Filed June 14, 1944 INVENTOR 62024? 57/56 BY LAQAJZQM ATTOR Patented Jan. 1, 1946 CORE SUPPORT FOR EXTRUSION MACHINES George Ritter, Millington, N. J., assi to The Ruberoid 00., New York, N. Y., a. corporation of New Jersey Application June 14, 1944, Serial No. 540,280

2 Claims.

This invention relates to an extrusion machine of the type comprising a die and a stationary core for making pressure pipe from an asbestoscement or flbro-cement composition, and more particularly to an improved core support for such machine.

It is necessary that the core of the machine be rigidly supported. Heretofore the core has been supported on a spider. While the spider supports the core satisfactorily, it has been found that pipes made on machines using a spider support develop longitudinal lines of weakness extending continuously throughout the wall corresponding to the position of the spider arms.

The primary object of the present invention is to overcome that objection by the provision of a concentric ring core support that will avoid form ing such lines of weakness in the wall and that will result in the production of pipes of increased beam, deflection, and hydrostatic strength. 1

The invention will be understood from the following description thereof, reference being had to the accompanying drawing in which:

Figure 1 is a vertical section through part of the extrusion machine, showing the core and its concentric ring support;

Fig. 2 is a view of the front face of the concentric ring core support;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2; and

Fig. 4 is a diagrammatic view of the material as passed through the openings of the concentric ring core support.

The machine comprises a cylindrical casing 9 in which the propeller blades l and the feed auger or screw ll rotate. The front or head end of the casing carries an encircling flange I2. Detachably secured to and disposed in front of this flange isthe support l3 for the stationary core H. A cylindrical partly tapered die I5 is detachably secured to and disposed in frontv of the core support l3. The material to be extruded is expressed in tubular form through the annular opening I8 between the core and the inner peripheral surface of the die.

The core support, to which this invention particularly relates, and which is indicated generally by the reference character |3, has an outer flange portion corresponding substantially in size and shape to the flange l2. The two flanges are detachably fastened together by bolts 8 passing through slots 9,

The support l3, as will best be seen on reference to Fig. 2, is in the form of a skeleton con sisting of a plurality of concentric rings connected together at intervals by radial arms. The entire support may be made of one piece or of several pieces suitably united together. The flange portion has an inner circular peripheral face 20. The interior diameter of the flange, at its circular face 20, is the same or substantially the same as that of the interior Wall or liner of the casing l0. Spaced inwardly from and concentric with that face are two ring portions 2| and 22, which portions are spaced from each other. As shown, the spacing of ring 2| from the face 20 of the flange I1 is somewhat less than that between the rings 2| and 22 but such spacing may be varied. In some cases more than two intermediate rings may be provided and in other instances only one intermediate ring may be needed depending on the diameter and wall thickness of the pipe to be made.

At the center of the support is a cylindrical ring member 23 in the opening of which the Stationary core i4 is rigidly supported. The member 23 is concentric with the rings 2| and 22v as well as the flange l1, and is spaced inwardly from the ring 22.

The several members or portions l1, 2|, 22 and 23 of the core supporting skeleton are connected together at intervals by relatively thin, radially extending armsor plates 24, 25 and 26. The arms 24 connect the flange i! with the ring 2|, the arms 25 connect the rings 2| and 22, and the arms 26 connect the latter ring with the core supporting ring 2|. The arms connecting each ring with the adjacent one are preferably spaced about from each other and it will be noted that the arms of the several sets, that is to say the arms 24, 25 and 26, are out of radial alinement with one another for the reasons hereinafter described.

By this arrangement a series of relatively long arcuate shaped openings or passages 21, 28 and 29 are provided between the several ring members or portions of the skeleton support, through which openings the material being extruded passes as it is deliveredfrom the auger II to the die 5, and by which it is formed into a plurality of concentric sections 30, 3| and '32 as indicated diagrammatically in Fig. 4 ofthe drawing.

The front end of each arm, that i the ends adjacent the die, are preferably so formed as to mold tongue and roove joints 33 in the meeting edges of the sections. This may be conveniently effected by providing the front end of .each arm with alternating'portions or flngers 34, 35 having oppositely directed angular faces 36, 31 which serve to mold intermeshing tongues and grooves in the side edges of the sections of the material as they are being discharged from the support.

Because of the fact that the radial arms connecting the several ring portions or members of the skeleton support are out of radial alinement with each other, the joints 33 formed in the several sectional tubes f all in circumferentially stagger'ed relation and thus avoid presenting longitudinal lines of potential weakness extending continuously throughout the thickness 'of the wall of the pipe. This results in the production of extruded pressure pipe of increased beam, defiection, and hydrostatic strength.

The rear face of the support 13 may be formed with rearwardly stepped circular flanges or projecting portions 38 that are received in corresponding recesses in the front or contacting face of the flange .2 so as to effect a tight Joint between the auger casing and the core support.

The front face of the support may have an annular recess or depression 39 for receiving the inner end of the die l5 and thus providing a tight fit between these parts. The die is detachably secured to the support in any suitable manner, as for example, by means of bolts 40, the inner threaded ends of which screw into tapped holes II in the support.' Means may also be provided to permit of any slight adjustment that may be needed for centering the die properly with respect to the core.

the longitudinal line breaks which were characteristic of the latter. It has also been found that the improved core supporting structure permits of use of longer asbestos fibres in the Portmade.

In extrusion of the asbestos-cement material Y violent and irregular, without any indications of While I have illustrated and described a preferred form of the core supporting structure and assembly, it is to be understood that modifications may be made thereof within the scope oi the claims.

What I claim is:

1. A core support for an extrusion machine, comprising an outer flange member having a circular inner face, a central member on which a core is supported, a'plurality of intermediate ring members concentric with the central member and the circular face of the flange member, the spacing between said members being gradually decreased from the central member to the flange member, and radial arms connecting the several members.

2. A core support for an extrusion machine, comprising an outer flange member having a circular inner face, a central member on which a core is supported, a plurality of intermediate ring members concentric with the central member and the circular face of the flange member, the spacing between said members being radually decreased from the central member to the flange member, and radial arms connecting the several members, said arms being out of radial alinement whereby the material passing through the support is divided into a plurality of concentric sectional tubes of different thickness with the Joints of the sections in circumferentially staggered relation, each arm having at its front end alternating oppositely inclined fingers for forming intermeshing joints in the side edges of the sections of material as they leave the support.

GEORGE/BITTER.

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