Claims
- 1. A method of casting a beveled concrete pipe in a pipe mold which includes a cylindrical outer mold case, and an inner cylinder disposed concentrically inside the outer mold case to form an annular mold cavity into which concrete is to be poured, the method comprising the steps of:
- (a) mounting the pipe mold so its axis is in an upright position;
- (b) mounting above the annular mold cavity a facing ring having a generally flat bottom surface and a plurality of spaced apart openings which together occupy a minor portion of the facing ring area, the facing ring being mounted in a plane inclined from normal to the upright axis of the pipe mold, the openings in the facing ring being located at least on low, intermediate, and high points of said inclined plane, the facing ring having a plurality of spaced apart doors for opening and closing respective openings in the facing ring;
- (c) mounting above the facing ring a plurality of pouring chutes each extending to a corresponding opening in the facing ring;
- (d) pouring concrete through the pouring chutes and the openings in the facing ring and into the annular mold cavity and distributing the concrete in the mold cavity unitl the level of the concrete reaches the vicinity of the facing ring bottom surface;
- (e) thereafter sequentially blocking further passage of concrete from the pouring chutes to the mold cavity to progressively block the rise of concrete in the mold cavity from the low side to the high side of the facing ring, and sequentially closing the doors in the facing ring, from the low side to the high side thereof, as the passage of concrete to the mold cavity is being progressively blocked, the bottom surface of each door being substantially flush with the flat bottom surface of the facing ring when each door is closed, the bottom surfaces of the closed doors cooperating with the facing ring bottom surface so that the rising concrete distributed in the pipe mold will come into contact substantially with the entire bottom surface of the facing ring and the bottom surfaces of the closed doors and form a smooth beveled end surface of the cast pipe; and
- (f) removing the pouring chutes and the facing ring from the pipe mold.
- 2. the method according to claim 1 including closing respective gates in the pouring chutes to sequentially block the passage of concrete to the mold cavity.
- 3. The method according to claim 1 in which the pipe mold includes a reinforcing cylinder disposed concentrically inside the outer mold case to form an annular outer mold cavity, and a cylindrical inner core disposed concentrically inside the reinforcing cylinder to form an annular inner mold cavity, and including the steps of:
- (a) mounting the facing ring above only the outer mold cavity;
- (b) mounting the pouring chutes above both mold cavities so the pouring chutes extend toward the corresponding openings in the facing ring; and
- (c) pouring concrete through the pouring chutes to distribute the concrete to the inner mold cavity and through the openings in the facing ring to the outer mold cavity.
- 4. The method according to claim 3 in which the cylindrical inner core has an annular top edge, and the facing ring has an annular inner edge and an annular support extending around the inner edge of the ring; and including the step of mounting the annular support so its rests on the annular top edge of the cylindrical inner core to hold the facing ring in its inclined position above the outer mold cavity.
- 5. The method according to claim 3 including periodically extending the length of the pouring chutes to circumvent the inner mold cavity and pour concrete directly through the openings of the facing ring and into the outer mold cavity.
- 6. The method according to claim 5 including continuously maintaining the level of the concrete in the inner mold cavity above that of the outer mold cavity to prevent the reinforcing cylinder from collapsing.
- 7. The method according to claim 3 including closing respective gates in the pouring chutes to sequentially block the passage of concrete to the mold cavity.
- 8. The method of casting concrete pipe in a pipe mold which includes a cylindrical outer mold case, a reinforcing cylinder disposed concentrically inside the outer mold case to form an annular outer mold cavity, and an inner cylindrical core disposed concentrically inside the reinforcing cylinder to form an annular inner mold cavity, the method comprising the steps of:
- (a) mounting above the outer mold cavity a facing ring having a plurality of spaced apart openings which together occupy a minor portion of the facing ring area, the facing ring including a plurality of spaced apart doors for opening and closing respective openings in the facing ring, the facing being mounted in a plane inclined from norml to the upright axis of the pipe mold;
- (b) mounting above the pipe mold a plurality of pouring chutes each being adapted to extend over a corresponding opening in the facing ring and over the inner mold cavity;
- (c) pouring concrete through the pouring chutes to distribute the concrete to the inner and outer mold cavities, the mold cavities being filled by alternately distributing the concrete from the pouring chutes to the inner mold cavity and then extending the length of the pouring chutes to circumvent the inner mold cavity and pour concrete directly into the openings of the facing ring to the outer mold cavity, the concrete being distributed in both mold cavities so that the level of the concrete in the inner mold cavity is always filled to a level essentially above that of the outer mold cavity to prevent the reinforcing cylinder from collapsing, the outer mold cavity being filled with concrete to the bottom of the facing ring, the doors in the facing ring being sequentially closed from a low side to a high side of the facing ring as the outer mold cavity is filled with concrete to the bottom of the facing ring, the bottom surfaces of the closed doors cooperating with the facing ring bottom surface so the facing ring will form a smooth annular end surface of the cast pipe between the reinforcing cylinder and the outer mold case; and
- (d) removing the pouring chutes and the facing ring from the pipe mold.
- 9. The method according to claim 1 in which the pouring chutes extend downwardly to their respective openings from a pouring surface elevated above the facing ring; and including the steps of pouring the concrete onto said elevated pouring surface to channel the flow of concrete downwardly from the pouring surface through the respective pouring chutes and into the corresponding openings of the facing ring until the concrete reaches the vicinity of the facing ring.
- 10. The method according to claim 1 in which the pouring chutes extend downwardly to their respective openings from a pouring surface elevated above the facing ring; and including the steps of pouring the concrete onto said elevated pouring surface to channel the flow of concrete downwardly from the pouring surface through the respective pouring chutes and into the corresponding openings of the facing ring until the concrete reaches the vicinity of the facing ring.
- 11. The method of casting concrete pipe in a pipe mold which includes a cylindrical outer mold case, a reinforcing cylinder disposed concentrically inside the outer mold case to form an annular outer mold cavity, and an inner cylindrical core disposed concentrically inside the reinforcing cylinder to form an annular inner mold cavity, the method comprising the steps of:
- (a) mounting the pipe mold so its axis is in an upright position;
- (b) mounting above the outer mold cavity a facing ring having a plurality of spaced apart openings which together occupy a minor portion of the facing ring area, the facing ring being mounted in a plane inclined from normal to the upright axis of the pipe mold, the openings in the facing ring being located at least on low, intermediate, and high points of said inclined plane, the facing ring having a plurality of spaced apart doors for opening and closing respective openings in the facing ring;
- (c) mounting above the pipe mold a plurality of pouring chutes each being adapted to extend over a corresponding opening in the facing ring and over the inner mold cavity;
- (d) pouring concrete through the pouring chutes to distribute the concrete to the inner and outer mold cavities, the mold cavities being filled by alternately distributing the concrete from the pouring chutes to the inner mold cavity and then extending the length of the pouring chutes to circumvent the inner mold cavity and pour concrete directly into the openings of the facing ring and into the outer mold cavity, the concrete being distributed in both mold cavities so that the level of the concrete in the inner mold cavity is always filled to a level essentially above that of the outer mold cavity to prevent the reinforcing cylinder from collapsing, the outer mold cavity being filled with concrete until the level of the concrete therein reaches the vicinity of the facing ring;
- (e) thereafter sequentially blocking the further passage of concrete from the pouring chute to the outer mold cavity to progressively block the rise of concrete therein from the low side to the high side of the facing ring so that the rising concrete distributed in the outer mold cavity will come into contact substantially with the entire bottom surface of the facing ring, the doors of the facing ring being progressively closed, from the low side to the high side of the facing ring, as the passage of concrete to the outer mold cavity is being progressively blocked, the bottom surface of each door being substantially flush with the bottom surface of the facing ring when each door is closed, the bottom surfaces of the closed doors cooperating with the facing ring bottom surface to form a smooth beveled annular end surface of the cast pipe between the reinforcing cylinder and the outer mold case; and
- (f) removing the pouring chutes and the facing ring from the pipe mold.
- 12. The method according to claim 11 in which the pouring chutes extend downwardly to their respective openings from a pouring surface elevated above the facing ring; and including the step of pouring the concrete onto said elevated pouring surface to channel the flow of concrete downwardly from the pouring surface through the respective pouring chutes and into the corresponding openings of the facing ring until the concrete reaches the vicinity of the facing ring.
- 13. The method according to claim 11 including closing respective gates in the pouring chutes to sequentially block the passage of concrete to the mold cavity.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 488,545, filed July 15, 1974, now abandonded which in turn, is a division of application Ser. No. 385,189, filed Aug. 2, 1973, now U.S. Patent No. 3,856,453.
This invention relates to the art of casting concrete pipe, and more particularly to a novel method and apparatus for pouring concrete into a vertically oriented pipe mold.
In the manufacture of certain types of large-diameter concrete pipe, for instance pipe having a diameter as wide as 20 feet, concrete is poured into a vertically disposed pipe mold comprising a cylindrical outer mold case and a cylindrical inner core. In most instances, the pipe is reinforced with a relatively thin-walled cylindrical steel shell, or cylinder, which is disposed in the pipe mold between the outer mold case and the inner core and becomes embedded in the pipe wall when concrete is cast in the pipe mold. The top of the cylinder generally is provided with a spigot-type end ring. When the concrete is poured into the annular space between the mold case and the cylinder, the top level of the concrete is "foreshortened" to form a flat annular end section which is spaced below the spigot ring so that during use, the spigot ring of the pipe can be joined with a cooperating bell-type end ring of an adjoining concrete pipe section.
In some instances, concrete pipe is cast as a straight pipe section in which the spigot ring and the foreshortened annular end section of the pipe lie in separate horizontal planes. In other instances, concrete pipe is cast as a beveled pipe section in which the spigot ring and the foreshortened annular end section lie in planes which are inclined relative to the axis of the pipe.
In the conventional method of casting concrete pipe, a "tamping top" is mounted on top of the pipe mold. The tamping top includes a "spigot round-up ring" engaged with the spigot ring to hold the top of the reinforcing cylinder in a fixed position, and a ring-shaped "halo bar" engaged with the top of the outer mold case to hold the case in a fixed position and maintain equal spacing between the reinforcing cylinder and the mold case. The tamping top forms a continuous annular opening between the cylinder and the mold case through which concrete is to be poured. Once the tamping top is in place, an inverted conical-shaped "pouring cone" is placed above the center portion of the tamping top. Concrete is then emptied from a bucket onto the top of the pouring cone which distributes the concrete evenly through the annular opening in the tamping top. The pouring cone also evenly distributes concrete to the annular space between the cylinder and the inner core. The space between the outer mold case and the cylinder generally is overfilled above its desired elevation, and after the pouring cone is removed, excess concrete at the top of the mold is then dug out by hand, measured with a depth gauge, and handtroweled to provide a flat, properly leveled annular end section for the pipe.
The job of hand-finishing the foreshortened annular end section of the pipe is a time-consuming and costly process, particularly because of the large size of the pipe, and because the finished end section of the pipe must meet relatively narrow tolerances. Beveled pipe in particular is laborious and costly to finish. The pipe form for beveled pipe generally is overfilled to form a horizontal annular end section, and the excess concrete on the low side of the bevel is then dug out and finished to the desired bevel by offset measurements which require substantial time and effort by the workmen.
This invention provides a system for vertically casting concrete pipe in such a way that the time-consuming and laborious prior art job of hand-finishing the annular end section of the pipe is substantially eliminated.
Briefly, the system includes a pipe mold having an outer mold case and an inner cylinder spaced concentrically inside the outer mold case. A flat facing ring is mounted above the annular space of the pipe mold, and a downwardly extending pouring chute is mounted concentrically above the pipe mold. The pouring chute is in communication with an opening in the facing ring. The pouring chute channels the flow of concrete into the opening in the facing ring, and the concrete is distributed in the annular space of the pipe mold until the mold is filled. When the concrete is filled to the bottom of the facing ring, the facing ring forms a flat, automatically leveled annular end section for the pipe which eliminates the need for the hand-finishing and measuring which are common in the prior art.
The facing ring may be mounted in a substantially horizontal plane to form the end section of a straight pipe, or it may be mounted in a plane which is inclined relative to the horizontal to form a beveled end section for the pipe.
In a preferred form of the invention, several radially extending and circumferentially spaced apart pouring chutes are aligned with corresponding circumferentially spaced apart openings in the facing ring. In instances where a beveled pipe section is produced, concrete is channeled into the openings of the facing ring by the pouring chutes until the concrete level reaches the low side of the facing ring. Thereafter, as pouring continues, gates in the pouring chutes are sequentially closed to progressively block the rise of concrete from the low side to the high side of the facing ring until the concrete is filled to the bottom of the facing ring, which will automatically provide a planar, beveled annular end section for the pipe.
These and other aspects of the invention will be more fully understood by referring to the following detailed description and the accompanying drawings.
US Referenced Citations (6)
Divisions (1)
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Number |
Date |
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| Parent |
385189 |
Aug 1973 |
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Continuations (1)
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Number |
Date |
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| Parent |
488545 |
Jul 1974 |
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Patent Grant
4101622
