US2025056A - Cable sheath extrusion press - Google Patents

Description

Dec. 24, 1935. Q Q JACQBSON 2,025,056

CABLE SHEATH EXTRUSION PRESS Filed Sept. 21, 19:53 a Sheets- Sheet 2 'INVENTOR M Q M BY fizmm wgqgi Dem-Z4, 1935. c. c. JACOBSON CABLE SHEATH EXTRUSI ON PRESS Filed Sept. 21, 1935 3 Sheets-Sheet 3 INVENTOR BY @ZMWL Patented Dec. 24, 1935 UNITED STATES PATENT OFFICE CABLE SHEATH EXTRUSION PRESS Application September 21, 1933, Serial No. 690,328

7 Claims.

My present invention relates to cable sheath extrusion apparatus and aims to provide certain improvements therein.

Among the objects of my invention are the following: (1) to provide an apparatus of the kind described, in the operation of which the quality of the cable sheath produced will not be dependent upon the human factor of the operator in charge of the apparatus; (2) to provide an apparatus wherein the inherent defects due to welds and oxide inclusions in cable sheath will be eliminated; and (3) to provide an apparatus wherein the flow lines in the cable sheath are reduced to a minimum. The invention also contemplates the provision of novel features in the construction and in the assembling of thevarious constituent parts of the apparatus whereby the assembly, disassembly, inspection and repair of any of the constituent parts is greatly facilitated, and wherein the product .of said apparatus will be more uniform, homogeneous and superior to lead cable sheath heretofore produced.

With the foregoing and other objects in View, my invention may be said to constitute an improvement over earlier apparatus for the same purpose invented by me and for which patent applications are now pending.

My present invention will be better understood from the detailed .description which follows, when considered in conjunction with the accompanying drawings, wherein:

Figure 1 is a vertical section through the apparatus taken substantially along the plane of y the line l-l of Fig. 2.

Fig. 2 is a top plan view of the apparatus.

Fig. 3 is a side elevation partly in section, as viewed from the left of Fig. 1.

Fig. 4 is an enlarged sectional view of a detail of the invention.

Referring to the drawings, let A indicate the furnace and its attendant parts in their entirety, B the extrusion press as a whole, and C the dieblock, said parts being in the nature of separate and distinct units adapted for assembly into one constituent whole.

The furnace A, as shown, comprises an enclosing furnace shell a having three elements or pegs 2a adapted to be supported upon a base or groundwork D and adjustable to hold the furnace in proper vertical position. The furnace is lined, as is customary, with fire brick 3a and provided with a fire box 4a and with a suitable vent opening 5a. Extending inwardly from the shell 0. near its top is supporting flange 60!. upon which rests an outwardly-extending flange e at the top of a melting kettle E which sets within the furnace housing above the fire box. Eccentrically disposed within the melting kettle and dependingly supported by the top or cover thereof, is a melting chamber 2c, the bottom of which is disposed in 5 spaced relation to the bottom of the melting kettle and has openings 3e therein, providing communication between the melting chamber and the melting kettle. Above the melting chamber is a charging hood 4e and a roller table 56 upon which the lead pigs are charged into the melting chamber. The cover of the melting kettle in spaced relation to the charging chamber extending therethrough is formed with a domeshaped portion 6e through the side of which extends a pipe 1e (Fig. 2) leading from a source of non-oxidizing gas 8e and provided with a valve 9e controlling the admission of such gas to the interior of the kettle. Through the top of the dome-shaped portion 6e extends a valve rod f, at the outer end of which is secured a hand wheel 2], and to the inner end of which is secured a plug valve F. The valve rod 1 is preferably in the form of a tubular member having a channel or bore 3 extending longitudinally therethrough, which channel is continued through the valve plug F. Above the normal surface of the molten metal within the melting kettle the valve rod 1 is provided with lateral openings 4] for establishing communication between the channel in the valve rod and the space above the surface of the metal in the kettle. The channel or bore in the valve rod from a point just below the lateral openings 4 to the outer end of the rod is somewhat enlarged, and extending into said enlarged bore is a second rod or pin G, the inner end of which is formed to constitute a valve adapted to seat against the shoulder formed by the bores of different diameter in the valve rod 1. The outer end of the rod G extends through the top of the rod f above the hand wheel 2 and is provided with a hand wheel g. Through a suitable connection (not shown) between the rod G and the outer end of the valve rod 1 the inner end of the rod G is adapted to be brought into and out of engagement with the shoulder valve seat formed between the bores of different diameters within the valve rod f and thereby function to establish or cut off communication between the lower portion of the bores through the valve rod f and the spaceabove the metal in the kettle. Suitable glands and packings are provided for the rods 1' and G to prevent the escape of gas therethrough or therearound.

Extending through the bottom of the kettle E end of a bent or angular draw-off tube H which extends into the kettle above the bottom thereof and at said end is provided with a valve seat for the plug valve F. For moving of the plug valve onto and from its seat, a suitable connection (not shown) may be provided between the rod f and a bushing Hie carried by the top of the dome member 66. The lower end of the draw-off tube H extends through an opening 1a in the furnace wall and may be suitably connected by welding or otherwise within an enlarged end in a passage 9' in the extrusion press cylinder J, said passage leading centrally into the bottom of a vertical extrusion chamber 27' in said cylinder. The draw-off tube H may be protected against excessive heat from the fire box by being enclosed in a suitable cast iron or refractory jacket h which may extend from a point just below the melting kettle to a point in close proximity to the extrusion press cylinder. For draining out all of the molten metal from the melting kettle E should such become necessary or desirable, I have provided said melting kettle at its bottom =with'adraw-off conduit He, the outer end of which is formed with a valve seat upon which a valve We carried by a rod [3c is removably seated.

The conduit He is supported by a fitting 8a extending through an opening 9a in the furnace wall, said fitting also providing a guide for the valve rod 136: and having a discharge spout 10a.

The extrusion press B is of the type having a vertically reciprocable ram K carried by a crosshead L, which, in turn, is rigidly connected to a pressure cylinder M through four tension rods or columns N. Also carried by the cross-head L and depending therefrom is a pair of plungers O which are movable in backing cylinders P carried by the press frame. 7

The extrusion chamber 2i at its bottom where it communicates with the passage :i is formed with a tapered valve seat 31' upon which is seatable a valve R carried by avalve rod 1" which extends axially through the ram K. The seating surface of the valve R is correspondingly shaped to the valve seat 37' and may be faced with a nonferrous metal 21' such as Monel metal, to prevent scoring of either the valve or the valve seat and thus insure against leakage when the valve is closed. To further insure proper seating of the valve it is rockingly carried by the valve rod through the medium of a rounded bottom pocket 3r formed in the top of the valve and into which extends and seats an'enlarged head 41' at the lower end of the valve rod, which head preferably has a curved or rounded surface of greatercurvature than the bottom.of the socket, the valve and valve rod being connected together through the medium of a T-head key joint which is held against unlocking by a pin 51' extending through said parts. For guiding the ram in its movements Within the cylinder 2i and to keep it from contacting engagement with the wall of said cylinder, I cause said ram to pass through a gland 47' which'is screw-threaded into the outer end of said cylinder.

To maintain the extrudable metal reaching the chamber 27- in the molten state any suitable means may be employed. I prefer, however, to heat the cylinder by circulating therein heating fluid, and to accomplish this I form the upper portion of the cylinder of two concentrically disposed engaging members J and J, the member J having a reduced cylindrical outer surface provided with spaced annular grooves 5:1 and the in axial alignment with the valve rod 1 is one member J having an inner cylindrical surface provided with spaced annular grooves 67', the member J being preferably shrunk upon the member J so as to bring the annular grooves into complemental relation. The resulting annular grooves are suitably formed for providing fluid communication therebetween and have connecting means for receiving and discharging the heating fluid. The cylinder J near its top is provided with a second group of communicating annular ducts 17' in which cooling fluid may circulate whereby to maintain the temperature around the gland 47 substantially below the congealing point of the molten metal within the cylinder. 7' and in the discharge passage 87 leading from the cylinder, the lower portion of the cylinder is annularly grooved, as indicated at 99, for accommodating suitable heating means, preferably gas fired means.

The cylinder M is disposed below the floor or foundation upon which the press is supported and is movable downwardly with the ram K upon the admission into said cylinder of hydraulic fluid through a fixed piston m through a pipe 2m. Upward movement of the ram K is accomplished by opening the passage leading into the cylinder M to waste and admitting hydraulic pressure into the backing cylinders P through the pipes 11-.

The ram K is connected to the cross-head Lin a manner to permit the ready disassembly of said parts so as to facilitate the inspection and repair of the ram when necessary, by having said ram provided with an enlarged cylindrical portion at its outer end Whereat it extends through a central opening I in the cross-head, and said enlarged portion 7c being formed with annular grooves 270 spaced apart a distance corresponding to the thickness of the press head, and said ram being held in assembled relation in said press head by split rings 3k which engage in the grooves 270 and are detachably held to the press head by bolts 410.

The valve rod r which extends through the ram K is mounted to have a close sliding fit therein and adapted for limited relative movement with respect to said ram. To provide the close fit aforementioned and preclude scoring and consequent binding of the valve rod within the ram, the latter is provided with non-ferrous bushings 57c and Gk, the latter being held within the ram by a sleeve 17c held in position by a threaded gland 8k. 7

For operating the lead valve R to cause and maintain the seating thereof upon the valve seat 37', there is provided valve operating means consisting of a hydraulic cylinder S formed in a casting T rigidly supported by the element J of the press cylinder J by rods t and within the cylinder S is movable a. piston 3 having a piston rod 25, which, at its outer end terminates in an en larged head 3s having a central cavity or socket into which the outer end of the valve rod 1' fits. The outer end of the cylinder S is closed by a head 45 having a central opening 58 therethrough, within which is connected the end of a pipe 68 for conducting hydraulic fluid to and from said cylinder. The hydraulic fluid is supplied to said cylinder S simultaneously with, and under the same pressure, as the hydraulic fluid supplied to the pressure cylinder M. The direction of flow of said hydraulic pressure'to the cylinders M and S is controlled by the handle 2t on the reversing valve T. To prevent injuring the apparatus should the operator failto reverse the flow of For maintaining the metal in the passage Cal hydraulic fluid at the end of the downward 'extrusion stroke, there is provided a safety device U (Fig. 3) which comprises a valve u having a valve pin Zu normally held seated by the fluid pressure acting upon the piston in the cylinder S, said valve u being adapted to be unseated to bypass the fluid from said cylinder through-the medium of the pivoted lever 3uand rod 4a which is guided through the press head L and which rod at its lower end is provided with an enlargement 5a which is adapted to be engaged by said press head L upon reaching its lowermost position and thereupon act through the rod 4n and lever 5314 to raise the valve U off its seat.

The discharge passage 87' leading from the extrusion chamber of the press has connected thereto one end of a connecting pipe V, the pposite end of which is connected to a receiving passage 0 in the die-block C. Within the pipe V is slidingly fitted a tube 21) of somewhat greater length than the pipe V, the ends of said tube being formed to seat against shoulders in the pipe connecting ends of the passages 87' and c and make leak-tight joints therewith. To facilitate the connection between said parts to insure efficient leak tight joints at the ends of the tube 20,

the connecting pipe V is provided at its opposite ends with a right hand and a left hand thread for connection with correspondingly threaded openings in said respective parts. To facilitate tightening said connecting pipe'it may be formed intermediate its ends with a wrench-engaging portion 1;.

The die-block C which is designed to receive the extruding metal in the molten state and extrude it in the congealed state, consists of a suitable member 20 having an extrusion chamber 30 extending axially therethrough and within which is axially positioned a core W. The extrusion chamber 30 is somewhat enlarged at the region of the receiving passage 0 leading thereinto, and within said enlarged portion of the chamber is an equalizer ring X. The enlarged portion of the extrusion chamber within which the equalizer ring is located, is of such form that the equalizer ring provides an annular conduit -'ic surrounding the ring and communicating with the receiving passage 0, and said ring has a plurality of circumferentially spaced radial openings w therein connecting the annular conduit with the chamber proper around the core. For draining the molten lead from the die-block it may be provided with a conduit 90 leading from the bottom of the annular chamber 40, and said conduit might have interposed therein a valve Hie which is operable from the exterior of the die-block. The valve, when opened, will permit the liquid lead to pass from the conduit 90 down and out through the drain pipe I I0.

In the operation of the apparatus hereinbeiore described, let it be assumed that during the heating of the lead kettle E the lead is melted therein in an atmosphere of an inert gas. Before starting the extrusion operation the valve F will be closed, the valve R will be open and the ram will be in its uppermost position preparatory to commencing the extrusion stroke. By opening the valve Se, gas from the tank 8e will flow into the top of the kettle above the molten lead therein. The valve G is thereupon opened, whereupon the gas from the kettle will flow through the valve stem f, draw-ofi tube H into the cylinder 27', through the connection pipe V and through the die-block extrusion chamber 30. Enough gas is permitted to flow through the apparatus to thoroughly evacuate the atmospheric oxygen therefrom. The valve G is then closed and the valve F opened, thus allowing the molten lead to flow into the extrusion cylinder and die-block, entirely filling the extrusion cylinder, the connecting conduit between the cylinder and the dieblock, and as much of the die-block as possible before said metal congeals near the delivery end or die therein. The valve F will remain 10 open during the entire operation of the press.

To start the extrusion operation, the reversing valve handle 2t is placed in position to supply hydraulic pressure to the extrusion cylinder M and valve operating cylinder S. This pressure will cause the cylinder M to move downwardly and carry with it the ram K, and also cause the piston s to move the valve rod r downwardly.

After about one inch travel of the ram, the

valve R will seat if the hydraulic pressure on the valve control piston s had not already seated the valve, thus closing the passage to the melting kettle. The molten lead in the extrusion cylinder 2i will then be forced through the discharge passage 81' and through the connecting conduit V to the die chamber conduit surrounding the equalizing ring and through the radial openings therein to the extrusion chamber proper of the die-block. As the molten lead is moved towards the die it is gradually being congealed and cooled to a temperature of approximately 350 F., and leaving the die at an extrusion speed which is controlled by the rate of hydraulic water supplied to the hydraulic cylinder M. At the end of the extrusion stroke the reversing Valve handle is moved to a position whereat the valve will function to permit the water from the cylinders M and S to go to waste and to simultaneously supply hydraulic fluid under pressure to the backing cylinders P to force the cross-head L upwardly and move the extrusion ram upwardly in its cylinder. After the valve rod 1, which will move upwardly with the ram K due to the frictional engagement therebetween, has traveled a distance of about one inch, its further movement will be arrested by the top of the rod 1 abutting the head 38 of the piston rod 28, which by this time has been moved into abutting engagement with the under side of the fixed cylinder S. The ram K, it will be noted, does not come into contact with the wall of the extrusion cylinder 27', thereby eliminating the possibility of scoring or cutting of the extrusion cylinder and the contaminating of the extrudable metal with steel chips.

The heating and cooling of the extrusion press and die-block may be automatically controlled by the circulation of suitable liquids through the annular openings in the extrusion cylinder and in the die-block and maintained by suitable standard temperature control equipment.

The heating and cooling fluids employed may be superheated steam, mercury, a mixture oi. diphenyl oxide and diphenyl or other suitable liquids, and of course, pumping devices suitable for operation with the chosen heating substance will be employed.

From the foregoing detailed description of the apparatus and the manner of its operation, it will be appreciated that I have provided a cable sheath extrusion device which is relatively simple in construction, efiicient and foolproof in its operation, and wherein the inherent defects in cable sheathing such as welds and oxide inclusions will be completely eliminated, and wherein the presence 01' flow lines will be reduced to a minimum. It will also be appreciated that although the present disclosure contains a preferred embodiment of my invention, I do not wish to have the same construed as defining the limitations thereof, since it will be apparent that changes in construction may be resorted to within the range of engineering skill without departing from the spirit of the invention.

What I claim is:

1. A cable sheath extrusion apparatus comprising an extrusion cylinder, a ram reciprocable in said cylinder, and a valve in one end of the cylinder controlling the admission of molten metal thereinto, cooperating means on the valve and the ram whereby said valve is adapted for limited movement with the ram.

2. A cable sheath extrusion apparatus comprising an extrusion cylinder, a ram reciprocable in said cylinder, and a valve-in one end of the cylinder controlling the admission of molten metal thereinto, cooperating means on the valve and the ram whereby said valve is adapted for limited movement with the ram and means for moving the valve independently of the ram.

- 3. A cable sheath extrusion apparatus comprising a cylinder, a ram reciprocable in said cylinder, and a valve in one end of the cylinder controlling the admission of molten metal thereinto, and a valve rod extending axially through the ram.

4. A cable sheath extrusion apparatus comprising a cylinder, a ram reciprocable in said the valve rod. 5

5. A cable sheath extrusion apparatus comprising a cylinder, a ram reciprocable in said cylinder, a valve in one end of the cylinder controlling the admission of molten metal thereinto,

a valve rod extending axially through the ram, 10

and fluid pressureoperable means for controlling the movements of the ram and the valve.

6. A cable sheath extrusion apparatus comprising a cylinder, a ram reciprocable in said cylinder, a valve in one end of the cylinder con- 5 trolling the admission of molten metal thereinto,

a valve rod extending axially through the ram, and fluid pressure operable means for seating the valve, said means being rigidly supported by the cylinder in spaced relation thereto. 7 20 7'. A cable sheath extrusion apparatus comprising a cylinder, a ram reciprocable'in said cylinder, a valve in one end of the cylinder controlling the admission of molten metal thereinto,

a valve rod extending axially through the ram, 5 fluid pressure operable means for controlling the movements of the ram and the valve, and a safety device comprising a second valve and means for opening said second valve at the end of the extrusion stroke for by-passing the fluid 30 from the fluid pressure operable means. a

CONRAD C. JACOBSON.

Images