Patent Grant
7488168
The present invention is related to a device and method for fabricating a concrete cylinder and a more specifically a device used to ensure that a reinforcing frame of the concrete cylinder remains at a predetermined radial location during the fabrication process.
Concrete pipes are employed in various civil engineering and architectural applications, such as culverts and building support structures, because of their high strength to weight ratio. Generally, concrete pipes are constructed by placing a reinforcing metal frame inside a mold or framework which is adapted to receive and cure concrete. The resultant concrete pipe generally includes a first end, a second end, an outside surface, an inside surface, and a reinforcing frame positioned therebetween that extends along a longitudinal axis between the first end and the second end.
One drawback of the construction of concrete pipes is that the placement of the metal frame relative to the outside and inside surfaces of the pipe may be altered as a result of the forming process. More specifically, it is desirable to maintain the radial location of the metal frame with respect to the internal diameter and outer diameter of the finished concrete pipe, wherein the theoretical structural behavior of the finished product is well characterized. If, for example, the metal frame is offset in the form during fabrication the pipe will have varying material properties, which may lead to localized cracking or frame buckling.
Thus, there is a long felt need in the field of concrete pipe fabrication to ensure that the reinforcing material used therein is located in the proper predetermined location subsequent to the forming operation, thus increasing the probability that the finished product behaves as theoretically expected. The following disclosure describes a device and method for selectively engaging a reinforcing frame to maintain its radial location within the concrete form during pipe fabrication.
It is thus one aspect of the present invention to provide an apparatus and method for centering a concrete pipe reinforcing frame during pipe fabrication. More specifically, one embodiment of the present invention includes a slotted flange that is operably interconnected to a dispensing shaft used in a traditional concrete pipe forming apparatus. In addition, the slotted flange is operably interconnected to a crank arm that is interconnected to a shaft. When the slotted flange is rotated the shaft rotates about an axis, thus swinging a centering arm radially outward such that it engages the inner diameter of the reinforcing frame. One embodiment of the present invention includes at least three centering arms that selectively engage the reinforcing frame used in the fabrication of concrete pipe to center the frame. The shaft is also operably interconnected to bearings that are mounted in pillow blocks that are interconnected to collars on the dispensing shaft. The centering arms are deployed while the dispensing shaft is slowly pulled out of the pipe forming mold during the forming process, thus maintaining the frame at its predetermined location which is preferably centered between an inner surface and outer surface of the cylinder.
It is another aspect of the present invention to provide an apparatus that is integrated into commonly used concrete pipe forming apparatus. More specifically, one embodiment of the present invention is added to concrete pipe forming apparatus that are currently in use, thus reducing costs to the manufacturer. A traditional apparatus is retrofitted initially by adding a split bearing to the dispensing shaft. The split bearing is generally a plate that provides a bearing surface for contact with the slotted flange. Then, the shaft mechanism, which includes the crankarm and the centering arm, is interconnected to a plurality of bearings that are mounted in pillow blocks that are interconnected via the dispensing shaft. Thus, very few alterations to traditional hardware are required to perform the present invention, which provides significant cost savings.
It is still yet another aspect of the present invention to provide a device that is constructed from common parts and materials, thus reducing manufacturing costs. For example, one embodiment of the present invention uses shafts and bearings made out of steel, or aluminum. The slotted flange and the split bearing are also constructed of steel or aluminum. Further, the collars used and described herein that interconnect to the dispensing shaft are commonly known in the art. Finally, the pillow blocks and bearings, as described herein, are known in the art and are employed in many rotating shaft operations.
Thus, it is one aspect of the present invention to provide a method for fabricating a reinforced concrete pipe, comprising the steps of:
providing a shaped form having an exterior dimension, an interior dimension, an upper end and a lower end;
positioning a reinforcing frame within said form, wherein said reinforcing frame has an exterior dimension and an interior dimension, and which extends substantially between said upper end and said lower end of said shaped form;
inserting a dispensing shaft into said lower end of said shaped form, said dispensing shaft having an upper end and a lower end and being capable of dispensing a concrete slurry into said shaped form;
providing a head interconnected adjacent to said lower end of said dispensing shaft, said head having an external dimension less than said internal dimension of said reinforcing frame, and which defines an internal dimension of said reinforced concrete pipe;
providing a plurality of centering arms operably interconnected to said dispensing shaft, said centering arms capable of reciprocating between a first retracted position and a second extended position, wherein in said extended position said centering arms define a dimension substantially equal to said internal dimension of said reinforcing frame;
reciprocating said centering arms to said second extended position, wherein said centering arms engage and thus center said reinforcing frame within said form;
pumping a predetermined volume of a concrete slurry through said dispensing shaft and into said form, wherein said concrete slurry covers said frame and extends against said form;
moving said head from said lower end to said upper end of said shaped form at a predetermined speed while retaining said centering arms in said second extended position;
withdrawing said head from said upper end of said shaped form;
allowing said concrete slurry to harden; and
removing said reinforced concrete pipe from said shaped form.**
The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description of the Invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these embodiments.
It should be understood that the drawings are not necessarily to scale. In certain instances, details which are not necessary for an understanding of the invention or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.
To assist in the understanding of the present invention the following list of components and associated numbering found in the drawings is provided herein:
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To fabricate a concrete pipe with the properly oriented reinforcing frame 2, initially the reinforcing frame 2 is placed inside the concrete form 12. Next, the dispensing shaft 10 is inserted into the concrete form 12 inside the reinforcing frame 2 with the centering arms 20 in their non-deployed and retracted position. Next, concrete from a hopper 30 is selectively fed through the dispensing shaft 10 and out of the dispensing head 32 into the form 12. This high viscosity concrete slurry 34 is of a low moisture content, or high slump, wherein it hardens fairly quickly. A force is then applied to the torsion arm 24, thus rotating the slotted flange 4, wherein the crank arms 14 rotate the shaft 16 and swing the centering arms 20 into place. The centering arms 20 engage the inner diameter of the reinforcing frame 2, thus ensuring that it remains substantially fixed during the placement of the remainder of the concrete slurry 34. The dispensing shaft 10 is then slowly removed from the form 12 while additional concrete 34 is dispensed through the dispensing head 32, thereby creating the pipe once the concrete cures. In one embodiment of the present invention, the centering arms 20 are constructed of one inch diameter pipe or solid rods that include curled ends to facilitate movement of the centering arm with respect to the reinforcing frame 2. More specifically, the curled ends of the centering arms 20 are oriented to prevent interference with the reinforcing frame 2. Once the centering arm 20 clears the top portion of the concrete form 12, the force on the torsion arm 24 is reversed, thus rotating the slotted flange 4 in the opposite direction to fold the centering arms 20 back to their original position. Finally, the dispensing shaft 10 is removed from the concrete form 12, thus forming a concrete pipe with an outside diameter and an inside diameter, defined from the inside diameter of the form 12 and the outside diameter of the dispensing head 32, respectively. The centering arms 20 ensure that the reinforcing frame 2 remains in its predetermined radial location during the retraction of the dispensing shaft 10.
While various embodiment of the present invention have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the scope and spirit of the present invention, as set forth in the following claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3262175 | Gourlie et al. | Jul 1966 | A |
| 5236322 | Willert | Aug 1993 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20050258558 A1 | Nov 2005 | US |
