US2997737A - Apparatus for withdrawing tubular objects from a mold - Google Patents

Description

Aug. 29, 1961 H. D. BOGGS EIAL 2,997,737

APPARATUS FOR WITHDRAWING TUBULAR OBJECTS FROM A MOLD Filed June 28, 1956 4 Sheets-Sheet 1 FIG].

INVENTORS HerZer?.D..Bo s Bea L,Mdf0 r7, /r

4 Sheets-Sheet 2 I II/ H. D. BOGGS ETAL IZI/A/ mvsmons //e Jeri 3.5

APPARATUS FOR WITHDRAWING TUBULAR OBJECTS FROM A MOLD Filed June 28, 1956 Aug. 29, 1961 O S F-ea Llfd fo glr ATTORNEYS APPARATUS FOR WITHDRAWING TUBULAR OBJECTS FROM A MOLD Filed June 28, 1956 Aug. 29, 1961 H. D. BOGGS ET AL 4 Sheets-Sheet 3 s? umn @H WMEWH n QN 2? T! E nc wmv L gm 3 A QHQ Aug. 29, 1961 H. D. BOGGS ET AL APPARATUS FOR WITHDRAWING TUBULAR OBJECTS FROM A MOLD Filed June 28, 1956 4 Sheets-Sheet 4 United States l atent APPARATUS FOR .WITHDRAWING TUBULAR OBJECTS'FROM A MOLD Herbert Briggs and Fred L. Magoon, Jr., Tulsa, Okla,

assignors, by mesne'assignments, to H. D. Boggs Company, Ltd., Omaha, Nebn, a limited partnership FiledJun'e 28, 1956, Ser. No. 594,565 Claims. (Cl. 18-2) This invention relates to apparatus for removing newly cast pipe from a casting mold.

More particularly, this invention relates to apparatus which is constructed and arranged to service a plurality of pipe casting molds by providing means for axially withdrawing newly cast pipe from each of said molds after the casting operation has been completed.

While the apparatus which will now be described is particularly adapted for use in connection with the axial withdrawal of newly cast fibrously reinforced plastic pipe from its casting molds, it should be understood that this apparatus would be similarly suitable for use in connection with the withdrawal of other types of pipe from cylindrical molds.

It is therefore an object of this invention to provide apparatus for axially withdrawing newly cast plastic pipe from a casting mold.

It is a further object of this invention to provide separate but co-operating means to first break the grip between a mold and a pipe that has been cast therein and to then withdraw the pipe from the mold.

It is another object of this invention to provide such apparatus which can service a number of casting molds which are aligned in a row, and which will allow the axial withdrawal of newly cast pipe without moving any of those molds from their aligned positions.

These and other o-bjects of this invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings in which:

FIGURE 1 is an elevational view, partially in section, of a cylindrical mold used for the centrifugal casting of P 1 FIGURE 2 is an'elevational view of the pipe-ejecting assembly;

FIGURE 3' is a plan View of the pipe-ejecting assembly;

FIGURE 4 is a section taken along lines 4'4 of FIG- URE 3; and,

FIGURE 5 is a section taken along lines 55 of FIGU-RLY 4.

In FIGURE 1' there is shown a pipe casting assembly, generally indicated at 76, which includes a pipe casting mold 162 mounted for rotation within the pipe casting assembly on bearings163; At one end of the mold, that is to say the end of the mold from which the newly cast pipe will be withdrawn, the mold 162 is counter-bored, at 165, and interiorly fitted with an annular collar 166, which is exteriorly dimensioned to fit into the counterbore, and has an interior diameter equal to the bore of the remainder of themold A v If the pipe to be cast is to have one end exteriorly threaded, the collar I66 may'have a threaded interior so as to act as a thread mold.

2,557,737 Patented Aug. 29, 1961 The mold illustrated in FIGURE 1 is occupied by a newly cast length of plastic pipe 355.

Referring to FIGURES 2, 3 and 4, it will be seen that the pipe ejecting assembly, generally indicated at 268, includes an elongated base frame, generally indicated at 270, which is mounted on flanged wheels 272 for movement alongrelatively transversely extending fixed rails 274, so that the entire pipe ejecting assembly can be transversely moved between a number of positions corresponding to a number of the casting mold assemblies, generally indicated at 76.

Ina preferred embodiment, the transverse movement of the entire pipe ejecting assembly 268 is selectively controlled by hand operated sprocket wheel 278 which is connected by chain drive 280 to a sprocket 282 on the shaft 284, upon which the wheels 272 are non-rotatably mounted. As will be evident hereinafter, it is quite important that the entire pipe ejecting assembly 268 be properly aligned with the axis of the particular mold which it is to service. The means for attaining this exact alignment include an air lock assembly, generally indicated at 286, which includes a pneumatic cylinder 288 having a piston rod 290 maintained in a position to selectively engage an aperture in one of the rails 274 when the pneumatic cylinder is suitably energized by operation of valve 296 on operating panel 298. The web of the rail 278 has an aperture drilled therein, at the same level as the piston rod 290, for every mold 76 which is to be served by the pipe ejecting assembly, and thus when the rod 290 enters such an aperture the pipe-ejecting assembly is properly aligned with a casting mold.

The transversely movable base frame 270, which consists essentially of a pair of suitably braced, longitudinally extending, spaced parallel rails 300, which may be formed of I-beams or the like, has a second frame, generally indicated at 302, which consists essentially of apair of suitably braced, longitudinally extending, spaced parallel rails 304, which may be formed of I-beams or the like, mounted thereon. The second frame 302 is supported on flange wheels 306 which are arranged to roll along rails 300 when the second frame is moved longitudinally of the base frame 270. Such movement is obtained by a pneumatic cylinder 308, depending from the second frame 302, having the free end of its piston rod 310 fixed to a fixed upstanding member 312 on the base frame 270. The pneumatic cylinder 308 is double acting and is coupled, by suitable lines, to a three-way control valve 314 located on the operating panel 298.

A pipe-ejecting carriage, generally indicated at 316, is disposed upon the rails 304 to move longitudinally thereof on wheels 318. The pipe-ejecting carriage 316 is positively actuated to move longitudinally of second frame 302 by a chain drive 320 extending longitudinally of the rails 304, and approximately midway therebetween, at a level slightly below their upper surface. The chain drive 320 is secured, at each end, to the pipe-ejecting carriage 316, as by draw bolts 322 (FIGURE 4), and extends around an idler sprocket 324 mounted at the mold end of the rails 304 and around a power sprocket 3'26 mounted at the opposite end of these rails. The power sprocket 326 is non-rotatably fixed to the shaft of reversible air motor 332, which is remotely controlled by a fourway valve 334 located on the operating panel 298.

As the pipe-ejecting carriage 316 serves to convey a section of newly formed plastic pipe 335, there are provided several pipe-supporting rollers 336 to bear the weight of, and to support, the pipe during the periods when it is on, or partially on, the pipe ejecting assembly 268. These pipe-supporting rollers are, when in their operative position, located midway between the rails 304 and at a level slightly below the surface thereof.

Each set of rollers 336 consists of an opposed pair of spaced coaxial truncated conical rollers having their minor ends facing each other. As best shown in FIGURE 2, when the pipe-supporting rollers 336 are operatively positioned at a level to support a newly formed pipe 335, and particularly a pipe of relatively small diameter, they will necessarily be located along the longitudinal path of the pipe-ejecting carriage 316. It is therefore within the contemplation of this invention to provide means for moving the pipe-supporting rollers 336 from their usual position when the pipe-ejecting carriage passes by.

To effect this end, each of the rollers 336 are rotatably mounted at the free end of one of two rocker arms 370 which extend, in spaced parallel relation, radially outward from a rocker arm shaft 372 which is rotatably mounted in suitable bearings (not shown) to extend under, and transversely of, the rails 304. An operating arm 376 is fixed to the rocker arm 372 and extends radially thereof. In the preferred embodiment illustrated, this rocker arm is angularly displaced from the rocker arm 370 and is pivotally connected to a drive rod 380 which is, in turn, connected with a piston rod 382 of pneumatic cylinder 384. The pneumatic cylinders 384 may be selectively operated from the operating panel 298 at such times as the pipe-ejecting carriage 316 approaches a given set of pipe-supporting rollers 336, or, as in this preferred embodiment, this operation may be entirely automatic by the provision of suitable mechanically operated valves, such as are well known in the art and need not be described in detail herein, which operate the pneu matic cylinders to lower the rollers 336 as the pipe-ejecting carriage 316 approaches.

It should be noted that the opposed truncated ends of the pipe-supporting rollers 336 are spaced from one another a distance sufficient to allow clearance of the chain drive 320 when the opposed rollers move as a unit, through an arc defined by the movement of rocker arms 370. While the preferred embodiment illustrated in FIG- URES 2 and 3 has two sets of pipe-supporting rollers 336, it should be understood that it may be desirable to provide additional sets of rollers, particularly when the pipe being ejected from the mold 162 is unusually long. In such a case, each set of pipe-supporting rollers would be provided with a means for lowering the rollers below the path of the passing pipe-ejecting carriage 316 which are similar to the means which have just been described.

Referring more particularly to FIGURE 4, mounted upon the pipe-ejector carriage 316 is a pipe-ejector pullout. As has been described hereinbefore, the end of the pipe mold 162 nearest the pipe-ejecting assembly 268 is counterbored and loosely fitted with a reinforcing collar 166, usually having an internal diameter equal to that of the rest of the mold, although it may have a threaded interior if threaded pipe is being cast. Generally speaking, the pipe-ejector pullout consists of an axially expanding circular wedge which is inserted within the lumen of the newly formed pipe 335 and then expanded to bear against the inner periphery thereof. The pipe is not distorted or injured as it has been cast in a closely fitted relation to the reinforcing collar 166. A hydraulic jack mounted on the pipe-ejecting carriage is then energized to urge the expanded wedge, and the pipe and reinforcing collar grasped thereby, toward the mold-ejecting carriage. The movement imparted by the hydraulic jack is relatively short, it being suflicient that the entire length of newly cast pipe be moved a short distance so as to break the typical initial bond or adhesion between the pipe and the mold 162. The pipe is then completely withdrawn from: the mold by the use of a powerful winch to draw the pipe-ejecting carriage along the rails 304. This apparatus will now be described in detail.

As shown in FIGURE 4, a cylindrical sleeve 400' mounted upon carriage 316 has a snugly fitting operatingrod 402 extending therethrough. A tube 404 is coaxially' cantilevered from the sleeve 400, and extends towards the mold assembly 76. The tube 404 has a longitudinally extending keyway 406 therein and has an interior diameter somewhat greater than the exterior diameter of operating rod 402. Slidably mounted and keyed (by key 407 fitting in keyway 406) within tube 404 is a sleeve 408 which is interiorly dimensioned to receive the operating rod 402 and has at least a portion of its lumen interiorly threaded to engage raised threads 410 formed upon a portion of the operating rod. The free end of the operating rod nearest the mold assembly 76 is reduced and formed with a truncated conical projection 412 which flares outwardly toward the free end thereof. The opposite end of the operating rod extends through a hollow hydraulic jack, generally indicated at 414, and has an operating wheel 416 fixed on the extreme end.

The conical projection 412 is provided with a segmental collar ring composed of four chordal elements 418 (FIG- URE 5) held together, and about the conical projection, by a tension spring member 420 disposed in a peripheral groove 422. The segmental collar ring is formed with an interior taper complementary with that of the conical projection 412 and has an exterior peripheral surface defining a right cylinder. In a preferred embodiment, the exterior or peripheral surface of each chordal element is formed with a number of fine serrations thereon so as to give it a better grip on the interior periphery of the pipe 335, as will be explained. In operation, the conical projection 412, circumscribed by the segmental ring 418, is inserted within the end of the mold 162 and so located that the segmental ring is within the area thereof which is fitted with the reinforcing collar 166. Rotation of operating rod 402, by suitable manipulation of wheel 416, causes an axial movement thereof away from the mold 162, due to the engagement of the thread 410 with the threaded interior of keyed, and hence nonrotatable, sleeve 408. The segmental collar 418, which is biased by tension spring 420 to snugly fit on the conical projection 412, moves towards the sleeve 408 until its end abuts the planar end surfaces of the sleeve. Further axial movement of the operating rod 402, and the conical projection 412, in the same direction, will cause the respective elements of the segmental ring to ride up the conical element until its peripheral surface contacts the interior of the pipe 335. It will now be seen that once such contact is made, further axial movement of the operating rod 402 will serve to wedge the serrations on the peripheral surfaces of the segmental ring 418 tightly against the interior of the newly cast pipe 335. As has been pointed out hereinabove, the strong reinforcing collar 166 snugly circumscribes this portion of the pipe 335, so there is no danger of distorting or injuring the pipe as long as reasonable forces are used. It will now be understood that the minor interior diameter of the conical projection 412 must be less than the interior diameter of the free end of the sleeve 408, so that the end of the segmental ring will properly abut the latter.

At this time the hollow hydraulic jack 414 is energized to urge the hub 420 of the operating wheel 416 away from the pipe-ejecting carriage 316. This movement will be experienced by the conical projection 412 and the segmental ring 418 and will tend to pull the pipe 335 out of the mold 162. As has been stated hereinbefore, this movement is only for a very limited distance, it being quite sutficient that the pipe be moved enough to break the bond or adhesion between the newly cast pipe 335 and the mold 162.

I As shown'in FIGURES2 and 3, awincli 430", powered by prime mover 432, is mounted atthe' end of second frame 302 furtherest fromthe mold assembly 76, and a cable 436 is rove about the winch. The free end of the cable 436 is fitted on pipe=ejecting carriage 316 and is utilized to draw the latter along rails 304, and, hence withdraw the newly cast pipe 335 from the mold 162 after the hydraulic jack 414-has beenoperated tobreak the initial bond or adhesion between the pipe and the mold. When the winch is being operated, the reversible air motor 332 is vented by theoperajon of valve 334 so that the motor offers no resistance to the winch. In a preferred embodiment, the operating controls 438 for the winch may be located on the operating panel 298 alongside the valve 334. As the pipe-ejecting carriage moves away from the mold, the pipe-supporting rollers 336 will rise to their operative position to provide suitable support for the length of the pipe 335 being withdrawn from the mold.

After the pipe has been completely withdrawn from the mold, the operating wheel 416 is rotated to relax the grip of the segmental collar ring 418 on the inner periphery of the pipe, in a manner that will now be understood, and then the pipe-ejecting carriage is moved moved away from the pipe a distance sufficient to clear the conical projection 412 and the segmental ring 418 from the interior of the pipe. The pipe is then removed from the pipe-ejecting assembly 268, by any suitable means, and the pipe-ejecting carriage is moved back to the mold end of the second frame 302 by the air motor 332 and the chain 320 so as to be ready to begin a new pipe-ejecting operation.

In FIGURES 2 and 3, the second frame 302 is illustrated as being so positioned as to be spaced from the mold assembly 76, when the pipe 335 is being withdrawn from the mold 162. It should be understoood, however, that when the hydraulic jack 414 is being operated to break the bond between the mold and the pipe, the mold end of the second frame 302 is positioned to abut the end of the mold 162; otherwise the pulling force of th jack would have a tendency to pull the mold 162 out of the mold assembly '76.

Having described only a typical preferred form and application of our invention, we do not wish to be limited or restricted to specific details herein set forth but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art and falling within the scope of the following claims.

We claim:

1. Apparatus for breaking the bond between an elongated hollow mold and an elongated hollow object cast therein, and for withdrawing the object from the mold comprising: a first frame mounted for selective movement transversely of the mold on a path adjacent the mouth thereof; a second frame mounted for selective movement longitudinally of said first frame in a direction parallel to the axis of the mold; carriage means mounted for selective movement longitudinally of said second frame in a direction parallel to the axis of the mold; selectively operable hollow object engaging means mounted on said carriage means; hydraulic means mounted on said carriage to move said hollow object engaging means axially of said mold, and away therefrom, a short distance to break the bond between said mold and said hollow object, such movement being independent of said carriage means; and means for moving said carriage means, together with said engaging means, away from said mold to withdraw the hollow object from said mold.

2. Apparatus for breaking the bond between an elongated hollow mold and an elongated hollow object cast therein, and for withdrawing the object from the mold comprising: a first frame mounted for selective movement transversely of the mold on a path adjacent the mouth thereof; a second frame mounted for selective movement longitudinally of said first frame in a direction parallel to the axis of the mold; carriage means mounted for seec ive mev mentz ona uslinally 9t aidse f me i a direction parallel tgthe of the mold; selectively operable hollow object engaging means: mounted on said carriage means; said hollowobject engaging means comprising a journal, an operating rod slidably mounted in said journal and extending therefrom in the direction of the mold alongan parallel to that of the mold, a radial wedge defined by a portion of the operating rod, said portion being without" said journal, radially expandng means mounted on-saidwedge to radially expand upon axial movement of said-rod relativeto said means, threads formed on another portion of said operating rod, said portion being without said journal, a nut threadably engaged with said threads, said nut being fixed against rotation and free to move axially relative to said journal; hydraulic means operable upon the engagement of said radially expanding means with the interior of the hollow object cast therein to move said operating rod axially of said mold, and away therefrom, a short distance to break the bond between said mold and said hollow object, said movement being independent of such journal; and means for moving said carriage means, together with said hollow object engaging means away from said mold to Withdraw the hollow object from said mold.

3. Apparatus for breaking the bond between an elongated hollow mold and an elongated hollow object cast therein, and for withdrawing the object from the mold comprising: carriage means mounted for selective movement longitudinally of said mold along a path axially aligned with the mold; selectively operable hollow object engaging means mounted on said carriage means; said hollow object engaging means comprising a journal, an operating rod slidably mounted in said journal and extending therefrom in the direction of the mold along an axis parallel to that of the mold, a radial wedge defined by a portion of the operating rod, said portion being without said journal, radially expanding means mounted on said wedge to radially expand upon axial movement of said rod relative to said means, threads formed on another portion of said operating rod, said portion being without said journal, a nut threadably engaged with said threads, said nut being fixed against rotation and free to move axially relative to said journal; hydraulic means operable upon the engagement of said radially expanding means with the interior of the hollow object cast therein to move said operating rod axially of said mold, and away therefrom, a short distance to break the bond between said mold and said hollow object, said movement being independent of such journal; and means for moving said carriage means, together with said hollow object engaging means away from said mold to withdraw the hollow object from said mold.

4. The structure defined in claim 1 wherein said hollow object engaging means comprises an operating rod, an expanding gripping means located at one end of said rod, and means for expanding said expanding gripping means into gripping contact with the interior of the hollow object in response to rotation of said rod.

5. The structure defined in claim 4 and further including threads upon the surface of said operating rod, means co-acting with said threads to convert rotation of said rod into axial movement of said rod relative to said carriage to expand said expanding gripping means.

References Cited in the file of this patent UNITED STATES PATENTS 859,656 Harbaugh et a1. July 9, 1907 889,31l Jones June 2, 1908 1,088,100 Saunders et a1 Feb. 24, 1914 1,455,686 Wallace May 15, 1923 1,499,620 Ladd July 1, 1924 (Other references on following page) 7 UNITED STATES PATENTS Ladd July 1, 1924 Murray July 13, 1926 Ball Nov. 16, 1926 D011 July 10, 1928 Ladd Aug. 6, 1929 Ladd Sept. 3, 1929 Carrington Sept. 23, 1930 Krissiep Oct. 28, 1930 Mathieu June 16, 1931 Weir Sept. 1, 1931 8 Barr et a1. May 29, 1934 Trotzke Aug. 12, 1941 Williams Aug. 12, 1952 Iobe Dec. 30, 1952 Trout et a1. Apr. 13, 1954 Hemm Apr. 20, 1954 Chanlund Feb. 21, 1956 Shatalofi May 29, 1956 Ligon Jan. 29, 1957 FOREIGN PATENTS Great Britain Mar. 28, 1935

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