Abstract:
A caisson tube finishing form includes a contact surface adapted and constructed to be secured to a caisson tube. A form surface is adapted and constructed to extend inwardly from an inner surface of the caisson tube. The form surface is in contact with concrete poured into the caisson tube during use thereof, and produces an aesthetically pleasing outer surface for the structural element resulting from use of the caisson tube.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    None 
       STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT 
       [0002]    None 
       FIELD OF THE INVENTION 
       [0003]    The invention relates generally to construction mechanisms, specifically to devices for increasing the speed, ease, and accuracy of building construction. 
       DESCRIPTION OF RELATED ART 
       [0004]    According to Lambert and MacDonald in their 1998 monograph titled “Reinforced Concrete—History, Properties &amp; Durability” (published by the Corrosion Prevention Association, Surrey, U.K.), the oldest known surviving concrete is to be found in the former Yugoslavia and was thought to have been laid in 5,600 BC using red lime as the cement. The first major concrete users were the Egyptians in around 2,500 BC and the Romans from 300 BC The Romans found that by mixing a pink sand-like material which they obtained from Pozzuoli with their normal lime-based concretes they obtained a far stronger material. The pink sand turned out to be fine volcanic ash and they had inadvertently produced the first ‘pozzolanic’ cement. Pozzolana is any siliceous or siliceous and aluminous material which possesses little or no cementitious value in itself but will, if finely divided and mixed with water, chemically react with calcium hydroxide to form compounds with cementitious properties. 
         [0005]    The Romans made many developments in concrete technology including the use of lightweight aggregates as in the roof of the Pantheon, and embedded reinforcement in the form of bronze bars, although the difference in thermal expansion between the two materials produced problems of spalling. It is from the Roman words ‘caementum’ meaning a rough stone or chipping and ‘concretus’ meaning grown together or compounded, that we have obtained the names for these two now common materials. 
         [0006]    Since the Romans had no powered cement mixers, they prepared small batches of concrete, and layered these batches either between wooden forms, or between facings of stone or brick already assembled. The Roman practice of pouring liquid concrete into wooden forms was rediscovered by the architect Bramante in the 15 th  century A.D., and incorporated into his early work on the Cathedral of St. Peter in Rome. 
         [0007]    The use of concrete forms continued to progress, with important developments including iron-reinforced structures in the 18 th  century and steel-reinforced concrete as a building material the mid-19th century. Among important recent developments has been the caisson tube, the most notable of which is the SONOTUBE, emerging in the mid-20th century. Caisson tubes are essentially paper tubes used for forming concrete for use as footers for decks, porches, and the like. Caisson tubes are widely available in diameters from 8 inches to 56 inches and in lengths to about 18 feet or so. In use, the caisson tube is set into the ground, and concrete is poured into the form and allowed to set. When the concrete is cured, the external paper layers above grade are stripped off, and further construction can continue. 
         [0008]    Unfortunately, although the footers produced using caisson tubes are structurally sound, they are frequently deficient in aesthetics. The exposed surfaces are often rough and unfinished, presenting an unsuitable appearance. Furthermore, it is frequently desirable to pour a plurality of tubes for a structure wherein all of the footer tops are to be poured at the same elevation. In current practice, the elevations are “shot” with a level and transit, and a nail is driven into each tube to indicate the desired pour level. 
         [0009]    Not surprisingly, there have been several attempts to improve the appearance and functionality of concrete column fabrication. For example, U.S. Pat. No. 6,401,411 to Maglio is directed to a post base having an upwardly-tapering portion. The base is designed to be at least partially buried in the ground. 
         [0010]    U.S. Pat. No. 6,098,353 to Stanfield deals with a sleeve for the buried end of a fence or sign post providing a watertight construction having an enclosing side and bottom walls. A base portion encloses the post and a capping portion joins with the base portion, providing a water tight connection, the capping portion having a water tight sealing wall or a gasket for contact with the side surface of the post. An adaptor section may be fitted between the base and the capping portions in order to extend the length of the assembly for posts that are to be placed deeply into the ground or other footing. 
         [0011]    In another example, U.S. Pat. No. 5,832,675 to Zuares shows a prefabricated flashing for post bases intended for installation in new or existing construction comprising two different pieces. One piece having a nailing flange which fits snugly around a post whose dimension is 3½″.times.3½″ has a total of eight nail holes and has four tapered sides that terminate in a bottom flange. The second piece is shaped and sized similarly to the first except that it is split vertically straight across the nailing flange and on one side has an extension of material which creates a seam. 
         [0012]    U.S. Pat. No. 5,271,203 to Nagle describes an elongate hollow support form having a continuous surface disposed about a central longitudinal axis and having opposed first and second opened ends and a first annular member, attached to the second opened end, for anchoring the elongate support form once the form has been positioned and a pourable setting material has been poured into the confines of the form. The first annular member forms a base section for supporting the support member and defines a cavity for accommodating the material. A second annular member can be provided adjacent the first end of the support form. After the pourable setting material has set inside the form, pourable setting material and the form become an integral structure. 
         [0013]    United States published application No. 20040111911 to Swinimer involves a prefabricated concrete form for the pouring of a footing for a structural pillar. The form is preferably constructed from a thermoplastic such as a high density polyethylene or ABS and is molded as a single disposable unit. The form is bell-shaped and has dimensions which render it useful in industrial size applications with large footprints. The dimensioning of the form also reduces the amount of material used for the manufacture of the form, allows the form to be backfilled without cave-in and to reliably support a tubular form for the pillar without an additional bracing or supporting structure. The form is in particular a low profile form wherein the sidewall is inclined at an angle below 45.degree. relative to the bottom edge. A top flange of the form is preferably adapted to accommodate two or more different diameters of the tubular form for the structural pillar. The sidewall may include integral ribs which open inwardly to facilitate evacuation of air as the form is filled and to lend rigidity to the sidewall. The sidewall may further include vent openings for the escape of air which is possibly temporarily entrapped during filling of the form. The advantage is an inexpensive form which does not have an excessive height despite large footprints, fills reliably and supports a tubular form for a pillar without the need for cross-pieces, even at sidewall angles below 45.degree. 
         [0014]    It can be seen from the foregoing that the need exists for a simple, inexpensive arrangement that improves the appearance and function of caisson tubes. 
       SUMMARY 
       [0015]    In accordance with the principles of the present invention, a caisson tube finishing form includes a contact surface adapted and constructed to be secured to a caisson tube. A form surface is adapted and constructed to extend inwardly from an inner surface of the caisson tube. The form surface is in contact with concrete poured into the caisson tube during use thereof, and produces an aesthetically pleasing outer surface for the structural element resulting from use of the caisson tube. 
         [0016]    The invention itself, however, both as to organization and method of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  illustrates a schematic perspective view of a caisson tube finishing form in accordance with the principles of the present invention. 
           [0018]      FIG. 2  illustrates a schematic sectional view of the  FIG. 1  caisson tube finishing form taken generally along lines II-II of  FIG. 1 . 
           [0019]      FIG. 3  illustrates a schematic sectional view of a caisson tube finishing form in accordance with the principles of the present invention in place in a tube. 
           [0020]      FIG. 4  illustrates a schematic sectional view of a footer resulting from the use of a caisson form finishing tube in accordance with the principles of the present invention. 
           [0021]      FIG. 5  illustrates another schematic perspective view of a caisson tube finishing form in accordance with the principles of the present invention. 
           [0022]      FIG. 6  illustrates a schematic sectional view of the  FIG. 5  caisson tube finishing form taken generally along lines VI-VI of  FIG. 5 . 
           [0023]      FIG. 7  illustrates a schematic bottom view of a decorative caisson tube finishing form in accordance with the principles of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0024]    While this invention is susceptible of embodiment in many different forms, there is shown in the drawings, and will herein be described in detail, exemplary embodiments, with the understanding that the present disclosure is to be considered as illustrative of the principles of the invention and not intended to limit the invention to the exemplary embodiments shown and described. 
         [0025]    A caisson tube finishing form  10  in accordance with the principles of the present invention is shown in  FIGS. 1 and 2 . The caisson tube finishing form  10  includes a contact surface  12  adapted and constructed to fit within, and be secured to, a caisson tube. In the illustrated embodiment, the contact surface  12  is a generally circular ring having a height H. With the caisson tube finishing form  10  fitted within a caisson tube, the height H is sufficient to cause the caisson tube finishing form  10  to be self-leveling to a large degree, i.e., it renders it physically difficult to insert the caisson tube finishing form  10  into a caisson tube in a skewed position. In the illustrated embodiments of  FIGS. 1 and 2 , the caisson tube finishing form  10  has a solid construction, giving it a generally triangular cross-section. 
         [0026]      FIG. 3  illustrates the caisson tube finishing form  10  in place within a caisson tube T. The caisson tube finishing form  10  is first placed in the tube T at a desired level L above a grade G, which can be determined using conventional mechanisms, such as laser levels and the like. Once the caisson tube finishing form  10  is at the desired level L, the caisson tube finishing form  10  can be secured in place using one or more fasteners  16 , such as nails or screws. With the caisson tube finishing form  10  in place, concrete is poured into the tube T up to the level L, any attachment brackets are put into place, and the concrete is allowed to set. Once the concrete has set, the outer portion of the tube T above grade is stripped away, leaving the structure S shown in  FIG. 4 . The structure S is a post base with a bracket B for receiving a deck post or similar structural element. Due to the presence of the caisson tube finishing form  10 , the structure S is provided with a finished, attractive inclined surface  18 . The surface  18  is superior to unfinished surfaces produced by known methods, since it is not only aesthetically desirable, but also eliminates the hazards of sharp edges in conventional structures. 
         [0027]    An alternative embodiment of a caisson tube finishing form  20  in accordance with the principles of the present invention is shown in  FIGS. 5 and 6 . The caisson tube finishing form  20  includes a contact surface  22  adapted and constructed to fit within, and be secured to, a caisson tube. In the illustrated embodiment, the contact surface  22  is a generally circular ring having a height H 1 . With the caisson tube finishing form  20  fitted within a caisson tube, the height H 1  is sufficient to cause the caisson tube finishing form  10  to be self-leveling to a large degree, i.e., it renders it physically difficult to insert the caisson tube finishing form  20  into a caisson tube in a skewed position. In the illustrated embodiments of  FIGS. 5 and 6 , the caisson tube finishing form  20  has a generally V-shaped cross-section. 
         [0028]      FIG. 7  illustrates a schematic bottom view of an alternative embodiment of a caisson tube finishing form  26  in accordance with the principles of the present invention. In this embodiment, the caisson tube finishing form  26  includes a form surface  28  having a plurality of decorative surface ornament elements  30 . The decorative surface ornament elements  30  can be formed in any desired pattern, in relief or extending outwardly from the form surface  28 . When the caisson tube finishing form  26  is removed after concrete has cured, the surface ornament elements  30  impart decorative patterns on the inclined surface of the finished structure. 
         [0029]    While details of the invention are discussed herein with reference to some specific examples to which the principles of the present invention can be applied, the applicability of the invention to other devices and equivalent components thereof will become readily apparent to those of skill in the art. For example, the caisson tube finishing forms of the present invention can be fabricated from any suitable material, such as plastic or metal. They can be either single-use or reusable. Accordingly, it is intended that all such alternatives, modifications, permutations, and variations to the exemplary embodiments can be made without departing from the scope and spirit of the present invention.