US2368751A - Method of and apparatus for charging extrusion presses - Google Patents

Description

1=|.6,1945.d M N. DUCLOS `v 2,368,751

METHOD oF AND 'APFARATUS FOR CHARGING ExTRusIoN, PRESSES Filed Dec. '27, 1941- 50 F16.: l? W3 i L 27 J 45 @ff/5 I Y ,u i /0 I g f l ,/4 I. /6/ ./2

l 4V nl Patented Feb. 6, 1945 METHOD OF AND APPARATUS FOR HARGING E XTRUSION ITRESSES Aeneas J. N. Duclos, South Orange, N. J., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application December 27, 1941, Serial No. 424,558

i A 5 claims.

This invention relates to methods of and apparatus for charging extrusion presses, and more particularly to methods of and apparatus fo'r charging cable sheathing presses.

Certain types of extrusion presses employed Q for sheathing electrical cables, have heating ,ket-

tles associated therewith to heat a charge ofv material for the press while the charge in the press is being extruded. Due to the inner contour of the outlet ends of pressesof this type, a certain amount of lone charge remains V.therein and is forced out ofthe press ahead of the next charge. However, the' upper surfaces of such remaining fractional Acharges have twice been exposed to air,

at the beginning andat the end of each extrusion operation when the press is open, resulting in the for an extrusion press and'feed the superheated 1 portion of the charge to the press in advance of the other portion of the charge to cause melting of the oxidized remaining fractional charge in the press, effecting passing of the oxidized material upwardly to the surface of the new charge and further effecting welding of the newv and fractional charges. I

Other objects and advantages will be apparent from the following detailed description when taken in .conjunction with the accompanying drawing, wherein y 7 i Fig. l illustrates an extrusion press and an associated heating kettle embodying the apparatus of the invention; l g Fig. -2 is a fragmentary vertical sectional view of the apparatus by means of which the method may be practised;

Fig. 3 is a fragmentary sectional view along the line 3-3 of Fig. 2; V;

Fig. 4 is a" fragmentary sectional'view taken along the line 4--4 of Fig. 3, and

Fig. 5 is a sectional view 'taken along the line 5 5 of Fig. 3.

' Referring now to the drawing, which illustrates the apparatus by means of which the method may be practised, attention is first directed to Fig. 1, which illustrates an extrusion taken vertically to a superheated chamber 26. The

press, indicated generallyat I0, and a-heating kettle, indicated generally at II. The extrusion press may be of the conventional type. includingA a cylinder I2, in which the material charges are disposed, provided with a suitable casing I 4. including la heating unit (not shown) to maintain the charge in the cylinder at a desired temperaturef A ram I5, operated through vsuitable mechanism (not shown) guided by one or more columns I6, may be moved downwardly, when the cylinder I2 is supplied with ai charge of material, to effect extrusion of the material through an outlet I 1 equipped with a suitable extrusion head to extrude the material on a cable I8.

The kettle Il may be ofthe conventionaltype, to receive the materialin'solid formand to convert it Iinto an extrudable state by heating it uniformly to a-suitabletemperature. It will be apparent that during the transferring of a charge of the material from the kettleto the press, the

ram I5 is positioned 4.out of the cylinder I2, as f illustrated in Fig. 1. vThe ram is then lowered into the cylinder and the extrusion operation may then begin. It is not possible, however, for the ram to force all of the charge out of the cylinder during its downward movement in the cylinder.

Therefore, a slug or fractionaiportion of the charge remains in the cylinder of the press. To

eliminate defects in the extruded sheath on the ca ble, due to the presence of an oxide coating on the remaining charge resulting in the prevention of perfect welding of adjacent charges, it is the.

The apparatus comprises a housing I9 rigidly" mounted by the aid of a bracket 2l), at an outlet 2| of the kettle I I. A passageway 22 in the housing I9 communicates with theoutlet 2l of the kettle I I and extends laterally at a slightly downward angle with an outlet to communicate with another lateral passageway 24, the latter communicating with a passageway 25 which extends chamber 26 has a base 21 mounted upon the housing I9, with an aperture 28 therein, completing -the passageway 25 into the chamber 26. -A cylindrical inner wall 30 ofthe chamber is surrounded by a suitable heating unit, such as an electrical heating coil 3|, the latter being suitably insulated and disposed inl an electrical circuit passageway 25 above the passageway 24, opens into a valve chamber 35 through an apertured valve seat 36. A valve 31, formed to cooperate with the valve seat 36 in opening or closing the passageway 34, is mounted upon a valve stem 38, the latter extending through a housing 39-and supporting a hand wheel 40 at the outer end thereof. A threaded portion 4I of the stem 38 cooperates with an internally threaded element 42 in the housing 39 to effect axial movement of the stem and valve upon rotation thereof. The valve chamber 35 has an outlet connection 43 threadedly secured in the housing I9 and provided with diametrically opposed pins 44 for the removable securing of a feeding spout 45 thereto, the latter having notches 46' (Fig. 3) of the bayonet slot type to receive the pins 44. The spout 45 extends at a suitable` angle, as illustrated in Figs'. 1 and 2, and is provided with a hooded outlet end 41 to extend over the open end of the cylinder I2 of the extrusion press, when the-ram I has been removed, to direct a material charge into the extrusion press. A suitable valve 50, actuable by a hand wheel or other desired means, is mounted to open and close the outlet 2| of the kettle.

Upon considering the operation of the apparatus and the carrying out of the method steps, let it be assumed that the extrusion press has completed one extruding operationand that the ram I5 has been removed from the cylinder I2 for another charge of material to'be supplied to the press. At this time, however, there'remains a fractional portion 49 of the previous charge in the cylinder, an upper surface 48 of which is being subjected to air by the removal of the ram Vfrom the cylinder. However, during the previous operation of the press, material `for another charge has been heated to an eXtrudable state in the kettle and, by gravity or other suitable force, a portion of the material in the kettle passed through the outlet 2| of the kettle, through the passageways 22, 24, 25 and 28 into the chamloer 26. This occurs, however, when the valve 31 is closed and the valve 50 is open. The chamber 26 thus becomes filled with a portion of the material for the subsequent charge, after which the valve 50 is closed and the material in the chamber 26 is subjected to greater heat than that to which the material in the kettle II is subjected. As a result, the materialin the chamber 26 is heated to a temperature far in excess of that essential for extruding.

At the time previously'stated, when the ram I 5 is in the position shown in Fig. 1 and the spout 45 is disposed in place, the valve 31 may be moved into the openpositlon to allow the charge to pass intoA the cylinder I2. The superheated material from the chamber 26 will contact the remaining fractional charge 49 in the cylinder I2, melting all or the upper portion of the fractional charge and thusfreeing the surface oxides. After thesuperheated portion of the charge has had suficient time to v,melt the remaining charge in the press or a portion thereof, the valve 50 is opened for the passage ,of enough material from the kettle to complete the charge. The freed surface oxides may then pass upwardly through the material of 76 the charge to the top thereof, where they may be skimmed off. The melting of the fractional portion 49v not only frees the surface oxides ibut effects a welding of the material of the two charges, so that the existence of defective portions in the sheath of the extruded cable will not Y exist.

After the charge has been supplied to the press, the spout 45 Vis removed and the oxidized material is skimmed off the charge. The ram I5 is then caused to move downwardly to enter the cylinder I2 and to begin another extruding operation. However, prior to the removal of the spout 45 the valves 31 and 50 have been closed, to cut off communication between the chamber 26, as well as the kettle I I, and the spout. 'Ihe kettle I I may then be supplied with additional material in solid form, to carry on the heating of material for another charge, the chamber with its heating unit again functioning, when supplied with its portion of the material through the actuation of the valve 50, to superheat the portion to bring about the same result to the fractional portion of the charge remaining in the cylinder. The relative locations of the passageways provide a trap or seal against air entering the chamber 26 or kettle I I.

It shallbe understood that the method includes the heating of a charge of material to an extrudable state, superheating a portion of that charge,

delivering the chargeto a cylinder of an extrusion press, with the superheated portion of the charge in advance of the remaining portion of the charge to cause melting of a portion of a fractional charge remaining in the cylinder oi' the press to effect freeing the surface oxides and welding the materials of the charges.

Although specific improvements of the invention have been shown and described it will be understood thatthey are but illustrative and that various modifications may be made therein without departing from the scope and spirit of this invention as defined by the appended claims.

What is claimed is:

1. The method of charging an extrusion press having a fractional remaining charge of material in the cylinder thereof, the method comprising heating a supply of material to a temperature sulicient to melt it, superheating another supply of material to a higher temperature than that of the first supply to condition the second supply to melt the exposed surface of the remaining charge when poured thereon, pouring the superheated supply into the cylinder to melt the por- .tion of the said remaining charge and to effect welding ofthe materials of the charges therewith,

and charging the cylinder with the first supply of material.

2. The combination with an extrusion press adapted to receive a charge of material in a cylinder thereof and to leave a fractional portion of the charge in the cylinder after an extrusion operation,of a kettle adapted to heat a supply of material to a molten state, a spofut to deliver the material to the cylinder of the press to charge the press, hollow means having a passageway affording communication between the kettle and the spout, a heated chamber communicating with the passageway at a given portion thereof to receive a portion of the material from the kettle and superheat it suiiiciently to melt a portion of the fractional charge when poured thereon,

and valves disposed at opposing sides of the said to free the superheated portion of the material from the chamber in advance of the main body of the material to effect welding of the materials in the cylinder by the superheated portion melting a portion 'of the fractional charge.

3. 'I'he combination with an extrusion press adapted to receive a charge of material in a cylinderthereof and to leave a fractional portion of the charge in the cylinder after an extrusion operation, of a to heat a supply of material to a molten state, a spout to deliver the material to the cylinder ofthe press to charge the press, a passageway, affording communicaticn between the kettle and the spout, formed'to retain a portion of the material therein to serve as a seal against the entrance of air, a heated chamber, communicating with the passageway at a-given portion thereof between the seal forming portion and the kettle, to receive a portion ofthe material from the kettle and superheat it sufciently to melt a portionl of the fractional charge when poured thereon, and valves disposed at opposing sides of the said given portion and actuable to selectively open and close their respective portions of the passageway to free the superheated portion ofthe materialfrom the chamber in advance of the main body of the material to effect welding of the materials in the cylinder by the superheated portion melting a portion of the fractional charge.

4.4The/l combination with an extrusion press adapted to receive'a charge of material in a cylinder thereof and the charge in the cylinder after an extrusion operation, of a kettle adapted to heat a. supplyo inato leave a fractional portion of Amaterial to a temperature material, a chamber adapted trol the oW of terial to a temperature suiiicient to melt the material, means to superheat another supply of material to a temperature higher than that of the rst supply to condition the second supply to melt the exposed portion of the fractional charge when poured thereon, a passageway extending from the kettle to the cylinder and having an intermediate connection with the said superheating' means, means to control the passageway to deliver the superheated material to the cylinder of the press to melt a-portion of the fractional charge, additional means to control the passageway to subsequently free the material from the kettle to charge the cylinder therewith.

5. The combination with an extrusion press adapted to receive a. charge of material in a, cylinder thereof and to leave a fractional portion of the charge in the cylinder after an extrusion operation, of a kettle adapted to heat a supply of sufficient to melt the to superheat a portion of 'the material to a. temperature higher than that of the supply to melt the exposed portionof the fractional charge when poured thereon, a feeding spout adapted to receive the material from the kettle and chamber, a valve to conthe material from ,the chamber to cause the superheated portion to pass through the yspout and intothe cylinder to cause melting of a portion of the fractional charge, and a valve actuable to free the material in the kettle to flow therefrom and through the spout to the cylinder to charge the cylinder.

AENEAS J. N. DUcLos.

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