US2445364A - Method of casting tubular elements - Google Patents

Description

July 20 1948- D. R. RANKIN E1' AL l2,445,364

METHOD 0F CASTING TUBULAR ELEMENTS Filed Oct. 12, 1945 3 Sheets-Sheet l FIG. I.

July 20 1948- D. R. RANKIN E1' Ax.v f 2,445,364`

METHOD oF CASTING TUBULAR'ELEMENTS Filed oct. 12, 1945 s snaps-sneer 2 Wwf Arme/yf V July 20, 1948- D. R. RANKIN Er AL METHOD oF CASTING TUBULAR ELEMENTS s sheets-Sheer s Filed Oct. 12, 1945 E K Q & .W.W\

Patented *July 20, 1948 METHOD F CASTING TUBULAR ELEMENTS Dan R. Rankin, Los Angeles, and John B. Wade,

Arcadia, Calif., assignors to Food Machinery Corporation, San Jose, Calif., a corporation of Delaware Application Qctober 12, 1945, Serial No. 621,906

. 2 Claims.

1 This invention relates to the molders art and is particularly useful in casting tubular structures. It is an object of this invention to provide a novel and efficient method of casting tubular structures.

Another object of the invention is to provide such a method which is particularly adaptable for providing tubular linings within tubular shells.

Yet another object of the invention is to provide such a method by which Venturi tube shells may be efficiently provided with cast metal linings requiring a minimum of machine work to produce a finished article.

Yet another object of the invention is to provide a method of molding in which a cooling medium may be applied to a core of the mold internally without substantial danger of this medium being admitted into contact with the molten metal in the mold, and while said mold is being whirled about an axis -disposed trans-. versely to and intersecting the longitudinal axis of the mold.

The manner of accomplishing the foregoing objects, as well as further objects and advantages, will be made manifest in the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a plan view of a preferred embodiment of the apparatus o'f the invention.

Fig. 2 is a front elevational view of Fig. 1. partly broken away to disclose hidden portions of the apparatus.' a portion of the apparatus shown in Fig. 2 being diagrammatically disclosed.

Fig. 3 is an enlarged diagrammatic sectional view.

Fig. 4 is a cross sectional view taken on the line 4-4 of Fig. 3.

Fig. 5 is a fragmentary side elevational view of the shiftable head end of the chuck of the in vention illustrating how this is shifted when introducing a mold into the chuck and when removing a mold therefrom.

Fig. 6 is an end elevational view taken in the direction of the arrow 5 in Fig. 5.

Fig. '1 is a longitudinal sectional view of a lined Venturi tube as this comes from the apparatus of my invention and before it 'hasbeen finished.

Fig. 8 is a fragmentary view of the right-hand end of the Venturi'tube shown in Fig. 7 as this appears after the final finishing step which foilows removal of said Venturi tubefrom the apparatus.

Referring specifically to the drawings, the molding apparatus therein disclosed is indicated 2 generally by the numeral i8. This includes a table il having legs I2 joined by a lower plate I8 and by a table top i4, the latter being surrounded by a wall i5. Swingably mounted on the left front corner of the wall I5 is a gas torch i9 and on the opposite front corner is Swingably mounted a ladle rest l1. The plate i3 is provided with a central bearing while the table top I4 has a central bearing 2l aligned vertically therewith. Mounted on the left side of thetablev il is an electric motor 22 which is connected by a belt 23 with a pulley 24 provided on a hollow shaft 25, upper and lower ends of which journal in the bearings 2| and 28 respectively.

The upper end of the hollow shaft 25 has a y shoulder 28 which fits within the inner race of the bearing 2i and a heavy flange 21 which overlies said bearing. The bore 28 of the shaft 25 `is of uniform diameter and extends throughout the length of the shaft 25 and upwardly through the shoulder 28 and flange 21. Provided in the flange 21 and leading from the bore 28 is a radial passage 29. Resting on the flange 21 is a heavy cap plate 30 having a passage 8i which connects with the upper end of the bore 28 and extends radially to the periphery of the cap plate 80. Screwed into threaded outer ends of the passages 2| and 3i are tubing connection nipples 32 and 23.

Resting on the plate 38 is an apron disc 38 and a mold chuck 48, the latter having a base plate 4i which rests on top of the disc 38 .and is secured to the flange 21 by cap screws 42 which extend downwardly through the base plate 4I, the disc 38, and the cap plate 90 and are screwed into suitable threaded -holes provided in the flange 21.

Welded to opposite edges of the base plate 4i is a pair of parallel chuck frame bars 49. Resting between and welded to opposite ends of these bars is a metal block 44 and a fixed chuck head- 45.V Provided in the block 44 is a horizontal bore 48 in which is slidably received a shaft 41, opposite ends of which are threaded. The outer end of shaft 41 receives lock nuts 48 and the inner end is screwed into a threaded hole provided in a shiftable chuck head 49.

'I'he block 44 also has four holes 50, opposite which corresponding holes 5i are provided in the shiftable chuck 49. These two sets of holes are occupied by coiled expansion springs 52 so as to springs 52.

The chuck 49 has an inner face 55 which is recessed to receive an annular packing 58 which shiaabie chuck 4s are studs so. similar studs sl are provided on and extend outwardly from adjacent ends of the bars 43.

The fixed chuck head 45 is disposed co-axially with the shiftable chuck head 49'and has an inner face 85 which is recessed to receive an annular packing 88. The head 45 has an axial passage `|51, the outer end of which is threaded. and has an elbow'tubing nipple 88 screwed therein. The passage 81 has an inner counter-bore 89 in which a short expansion spring is mounted. Connecting the nipple 88 with the nipple 32 is a metal tubing 1 I.

The chuck 40 is adapted to be actuated by a toggle wrench comprising a handle 18 which is bifurcated to provide arms 11 having notches 18 at their extremities and to which is pivotally connected a yoke 19 formed of two hooks 80 and a connecting band 8|.

The manner of using the toggle wrench 15 is illustrated in Fig. 5. Here it is seen that the yoke 19 is allowed to come to rest on the shiftable chuck head 49 so that the hooks 90 engage the studs 80. The handle 18 is now manipulated to bring the studs 8| within the notches 18. The handle 18 is now pressed down to swing this into its broken line position in Fig.` 5. This collapses the springs 52 and shifts the chuck head 49 towards the stationary block 44. The chuck heads 45 and 49 are thus separated to permit the insertion of a mold 85 between these heads.

As the apparatus |0 is especially useful in casting liners in Venturi tube shells, the mold 85 is shown as including such a shell 88. This shell has a typical long tapering bore 81 with a short outwardly flaring mouth 88 at the narrow end of the bore 81. The shell 88 is provided with a gate or pouring hole 89 which is disposed approximately midway between its opposite ends and when the shell is assembled in the mold 85 and the latter held in the chuck 40, this hole is disposed coaxially with the hollow shaft 25.

Ihe mold 85 also includes a core 90 comprising a long tapering core element 9| and a short tapering core element 92 which slips over the small end of the core element 9| and into the flared mouth 88 of the bore 81 of the Venturi tube shell 88 when the element 9| is inserted into this bore from the opposite end thereof. The core element 9| has a hole 93 disposed axially therein and extending throughout its length. The core element 92 has a bore 94 which snugly receives the small end of the element 9| and is counterbored to receive a packing ring 95 and a packing follower 98 which is adapted tobe pressurably contacted by the spring 10 when the mold 85 is placed in the chuck 40. The core element 9| has permanently secured thereto a sleeve 91 which is adapted to slip over and be secured to one end of the shell 88 by a set screw 98. This sleeve has an annular bead 99 which is adapted to engage the packing ring 58 to form a tight seal when the mold 85 is placed in the chuck 40.

The core element 92 is provided with an annular sleeve |00 which is adapted to slip over and be secured to the shell 88 by a set screw 0| This sleeve has an annular bead |02 which is adapted to press against and make a sealing engagement 4 with the Packing ring 88 when the mold 95 is placed in the chuck 40.

From the description of the mold 85, it is seen that the assembly of the parts thereof provides a mold chamber ||0 with which the pouring gate 89 communicates. It is also seen that the seals effected by the packing rings 58 and 88 provide a practically fluid tight connection between the core passage 93 and the passages 51 and 81 in the chuck heads 45 and 49. In a manner which will be made clear hereinafter, this connection facilitates the application of a cooling medium internally to the core 90.

The bearing 20 has a downward tubular extension I5, the lower end of which is threaded to receive an adapter H6. Provided in the tube ||5 is a threaded hole ||1 into which a'pipe ||8 is screwed.V (Fig. 2.) This pipe leads to a water supply tank ||9 which is kept filled with water. by a float control valve |2|, up to a level |20 (which is lust below the level of the axis of the mold when held in the chuck 40). Screwed into the threaded opening |22 f the adapter ||8 is a three-way fitting |23 whic connects with a tube |24 terminating in a vacuum gauge |25 and with a pipe |28 which leads to the suction end of an ejector |21. The ejector |21. is operated by air supplied thereto under high pressure from a pipe |28 which is controlled by a valve |28.

Pressed into the lower end of the hollow shaft 25 is a tube |40 having holes |4| formed therein opposite the hole ||1 in the tube ||5. Surrounding the tube |40 and pressed into the lower end of the tube ||5 is a sleevev |42 having packing rings |43 on its opposite ends which seal off the space around the tube |40 between these rings. The sleeve |42 has a hole |44 which communicates between this space and the threaded hole 1.

Disposed axially in and extending throughout the combined length of the hollow shaft 25 and lower tubular extension |40 thereof is a small diameter tube |50, this being held in place at its upper and lower ends by packing rings |5| and |52 which seal off the space in the shaft 25 and tube |40 surrounding the central tube |50.

Operation 'I'he manner in which'the apparatus |0 of my invention is preferably employed in carrying out the method thereof is as follows:

A considerable number of the mold cores are provided andthese are assembled with Venturi tube shells 88 and heated in an ove to approximately the melting temperature of the metal with which liners for the shells 88 are to be cast. This metal may be of any type suitable for die-casting work but preferably is babbitt. When a lot of molds 85 have thus been assembled and heated and one of these has arrived at the proper temperature, it is picked up by a pair of tongs and the toggle wrench 15 applied, as shown in Fig. 5, to retract the shiftable chuck head 49 and permit the hot mold 85 to be placed between this chuck head and the fixed head 45 and in axial alignment with these. then released and removed to allow the springs 52 to press the mold 85 between the chuck heads 45 and 49. When this is done, the seals above described are effected by the packing rings 5J. 88 and 95.

The motor 22 is now energized to rotate the chuck 40 and the mold 85 mounted therein about the axis of the mold gate 89. The torch I8 is then lighted and swung inwardly as shown in Fig. 1

The toggle wrench 15 is to bear directly on the shell I5 adjacent the hole I9. The ladle rest |1 is also swung towards the center of the apparatus as shown in Fig. 1 and a ladle L containing molten metal is placed across the restll as shown in Fig. 2 and metal poured therefrom through the mold gate 99 until the mold chamber |||l is lled. The air valve |29 is now opened so that flow of this through the ejector |21 imposes a suction on the pipe |26 which is transmitted through the small tube |50, passage 3|, tube 59, nipple '59 and passage l1 to the axial cooling iluid passage 93 in the core element 9|. As Water seeks its own level, water will ilow from the tank |19v to the pipe HI through the holes |44 and |4| into the tube |40 and hollow shaft 25 and out of the upper end of this into passage 29, nipple 32 and tube 1|. As soon as a suction is imposed, as noted, upon one end of the cooling fluid passage 93 in the core element 9|, a supply of water is readily available to the opposite end of this tube. Water is thus sucked into the passage 9| and of course is converted immediately into steam. This is withdrawn from the case by the suction imposed thereon and the stream is drawn downwardly into the central tube |50 which is kept cool by the surroundingrwater thereby condensing the steam' and creating a vacuum which accelerates the removal of the steam from the central core passage 99.

The water thus admitted to the passage 9| rapidly cools the core 90 causing the molten metal in the mold chamber to contract and the operator continues to pour metal from the ladle L into the hole I9 until the metal in this hole congeals.

The manner of introduction of the cooling medium into the core 90, that is by suction, eliminates the possibility of this cooling medium being forced into the mold chamber H0 where it would contact the molten metal and cause an explosion.

When the metal in the ga'te 99 has congealed,I the valve |29 is closed, the torch I6 and ladle rest ll are swung out of the way and the motor 29 is de-energized. The motor is preferably equipped with an automatic brake which sets itself when the motor is shut ofi' to quickly automatically bring the revolving chuck 49 to a standstill.

The wrench 15 is again applied as shown in Fig. and the chuck heads 49 and 45 separated to permit the mold 95'to be removed by a. pair It is also to be understood that while my invenl tion is especially adapted i'or providing linings in Venturi tubes, it is not limited to this use and may be employed for casting tubular linings in tubular shells generally.

We claim:

1. A method of employing a mold and a core,

the latter having a hole extending therethrough from end to end, in the casting o1 a tubular element which method comprises placing said core in said mold, rotating said mold rapidly about an axis transversely intersecting the axis of the mold, and, while said mold is being so rotated,

pouring a stream of molten metal into said mold of tongs applied thereto. This mold is now placed in an arbor puller and after the set screws 99 and I0| have been loosened, the core elements 9| and 92 are pulled from the opposite ends of the liner |65 which has just been cast in the Venturi tube shell 96. This leaves the product, a completedv Venturi tube |66, as shown in Fig. 7, free from the core elements of the mold and ready for the ilnal finishing step. This consists in removing the -annular iin |51 occurring at the juncture of the core elements 9| and 92 by a machining opalong said axis of rotation, supplying a cooling liquid to one end of said hole, and applying suction to the other end of said hole.

2. A method of employing a metallic mold and a metallic core, the latter having a hole extending therethrough from end to end, in the casting or a tubular element which method comprising placing said core in said mold, heating said mold and core to a temperature approximating the melting temperature of the casting metal, rotating said mold and core rapidly about an axis transversely intersecting the longitudinal axis of the mold and core and, while said mold is being so rotated, pouring a stream of molten casting metal into said imold along said axis of rotation, supplying a cooling liquid to one end of said hole, and applying suction to the otherend of said hole.

DAN R.. RANKIN. JOHN B. WADE.

Y REFERENCES CITED The following references are of record inthe ille of this patent:

UNITED STATES PATENTS Number Name Date 44,521 Emery Oct. 4, 1864 1,320,910 Perry Nov, 24, 1919 1,433,763 Warn et al. Oct. 31, 1922 1,752,280 Sawtelle Mar. 25, 1930 1,987,784 McDonald Jan. 14, 1935 2,070,852 Bannerman Feb. 16,1937 2,187,720 Williams Jan. 23, 1940 2,208,230 Rublssow July 16, 1940 2,273,614 Batie Feb. 1'1, 1942 2,370,953 Greenberg Mar. 6, 1945 2,385,631 Levinson 'Sept. 25, 1945

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