Ledger Form For Concrete Structures

Abstract

An intermediate form section interconnects the vertical and horizontal form sections of a concrete wall and ceiling form, and concrete-engaging ledger means on the intermediate section allows the latter to support the horizontal section when the vertical wall section has been removed. The intermediate section is also provided with horizontal and vertical segments which abut the horizontal and vertical sections respectively, and also has inner and outer elements disposed in spaced interconnected relationship to constitute a form for that portion of the concrete wall which is contiguous with the ceiling. Ledger means on each of the elements are disposed in opposed planer relationship to assure maximum distribution of the weight of the horizontal section.

Description

This invention relates to concrete building forms and, more particularly, to a concrete wall and ceiling form which permits a horizontal section of concrete to be poured prior to the complete setting up of the vertical sections therebeneath.

Concrete building forms of the type wherein a plurality of panels are held together by pin assemblies, and inner and outer form sections are interconnected by spanners which extend through the concrete and through which the pin assemblies themselves extend, have achieved universal acceptance in the construction industry. One of the major factors in the time and labor required to construct a concrete building using these forms has heretofore been the necessity to wait until the vertical wall sections are completely set up before the horizontal floor and ceiling sections are formed. This delay is required because of the need to provide vertical support for the horizontal form sections and particularly that portion of the latter which is contiguous with the vertical wall. If this support was provided by placing the horizontal form sections on top of the vertical form sections it would be extremely difficult to remove the latter under the weight of the concrete in the horizontal sections. On the other hand, it is not possible to provide the necessary support from external sources without damaging that portion of the vertical wall immediately adjacent the ceiling, until the wall has cured for a considerable period of time.

It is therefore an important object of the present invention to provide a concrete building form utilizing both horizontal and vertical form sections wherein an intermediate form section engages the concrete wall to support the horizontal form section when the vertical section has been removed.

An equally important object of the present invention is to provide a concrete form as described above wherein the construction of the intermediate form section allows placement of the horizontal sections immediately after removal of the vertical form sections from the concrete wall and before the latter has completely set up.

Still another object of the invention is to provide a concrete building form utilizing horizontal and vertical form sections wherein the external vertical support required for the horizontal form section is reduced or eliminated by incorporating into the form an intermediate section which abuts both the horizontal and vertical sections and is provided with concrete-engaging means which allows the intermediate section which abuts the two previously mentioned sections to be configured to present a true corner between the horizontal and vertical form sections.

Additionally, an important object of the invention is to provide a concrete building form as aforesaid, wherein the intermediate form section allows for compensation of any shrinkage in the vertical walls which occurs during the initial setting up period of the concrete as a result of the connection between the intermediate section and the horizontal form section.

Referring to the drawing:

FIG. 1 is a fragmentary cross-sectional view through a concrete wall showing the horizontal, intermediate, and vertical form sections in interconnected relationship as they would appear prior to pouring of the concrete ceiling;

FIG. 2 is a fragmentary cross-sectional view similar to FIG. 1 after removal of the vertical form sections and after pouring of the concrete floor;

FIG. 3 is a cross-sectional view through a concrete floor and a pair of concrete walls showing the concrete forms and their external supports in elevation;

FIG. 4 is a fragmentary cross-sectional view similar to FIG. 3 after the vertical form sections have been removed from the concrete walls and the horizontal concrete ceiling has been poured; and

FIG. 5 is an enlarged fragmentary elevational view of a concrete wall constructed according to the teachings of the present invention with a horizontal ceiling section shown in cross section in overlying relationship to the wall.

Concrete building forms of the type to which the present invention is directed are shown and described in detail in U.S. Pat. No. 3,447,771 which issued on June 3, l969, to James E. Trimmer, the present applicant. The foregoing patent is incorporated herein to the extent necessary to obtain a complete and full understanding of the present invention.

Referring initially to FIGS. 1-3, a vertical form section 10 is connected with a horizontal form section 12 through an intermediate form section 14. Each of the vertical sections 10 includes an inner portion 16 which is disposed in spaced relationship to an outer portion 18 and held in interconnected relationship with the latter by a plurality of horizontal spanners 20. Each of the portions 16 and 18 is constructed from a plurality of side-by-side panels as disclosed in the referenced patent. Also as described in the aforementioned patent, the paneled sections which comprise the portions 16 and 18 are held together by pin-and-wedge assemblies 22 which assemblies also connect the spanners 20 to the respective inner and outer portions 16 and 18.

Each of the intermediate form sections 14 has an inner element 24 which is disposed in spaced relationship to an outer element 26 and interconnected with the latter through a plurality of spanners 20 in the same manner as described for the inner and outer portions 16 and 18. Each of the inner and outer elements 24 and 26, respectively, comprises an elongated L-shaped member the respective legs of which form horizontal and vertical segments which abut respectively the horizontal form section 12 and the adjacent portion of the vertical form section 10. The vertical segment of each of the respective elements 24 and 26 is disposed at a right angle to an adjacent horizontal segment and is preferably at least twice the length of the horizontal segment. Each vertical segment is also provided with inwardly projecting concrete-engaging ledger means in the form of a V-shaped member 28 which is integral with the vertical segments. It is to be noted that the legs of the V-shaped member 28 are disposed at a right angle relative to each other and when the inner and outer elements 24 and 26 are disposed on either side of a vertical concrete wall 30 the V-shaped ledger members 28 are in opposed relationship in the same horizontal plane.

As best illustrated in FIGS. 1 and 2, each of the respective inner and outer elements has a perpendicular flange portion 32 comprised of horizontal and vertical components which are normal to the respective horizontal and vertical segments. Each of the flange portions 32 has an opening 34 in its vertical component for receiving a pin assembly 22 of the type previously described to thereby interconnect the inner and outer elements 24 and 26 through a spanner 20. Second and third flange portions 36 and 38 on each of the elements 24 and 26 extend perpendicular to the first mentioned flange 32 in vertical and horizontal planes, respectively, and each is provided with an opening similar to the opening 34 for receiving a pin assembly 22 to thereby connect the intermediate form section 14 to the respective abutting horizontal and vertical form sections 10 and 12.

As illustrated in FIGS. 3 and 4, a pair of support jacks 40 which are disposed beneath the horizontal section 12, along with cross braces 42 provides vertical support for the horizontal section 12 when a layer of concrete 44 is poured on the latter to form a ceiling. A floor-to-ceiling cross brace 46 provides the necessary vertical support for that portion of the horizontal form section 12 which supports the layer of concrete 44 extending out over the vertical wall 30 to form a ledge or overhang.

When a building is to be constructed having concrete walls and ceilings, a plurality of the panel sections which comprise the vertical form sections 10 are placed in side-by-side relationship and interconnected through pin assemblies 22. It is to be understood, that while only a single panel section is shown forming the inner and outer portions 16 and 18 of the vertical section 10 in the drawing, any number of panel sections can be placed in end-to-end relationship as well as in stacked relationship to form either the inner portion 16 or the outer portion 18. The intermediate form sections 14 are then placed atop the uppermost panel section of the respective inner and outer portions 16 and 18, and connected thereto by the pin assemblies 22. Finally, the horizontal form sections 12 are secured to the intermediate sections 14 by pin assemblies 22 afterwhich the vertical supports 40 and 42 are properly positioned. Concrete is introduced into the area between the inner and outer portions 16 and 18 of the vertical form section 10 to form the concrete wall 30. After a brief setting up period, the vertical forms 10 are removed from the wall 30. At this point, it should be mentioned that in many cases it is desirable to use the same panel sections which were used in forming the vertical section 10 to construct the horizontal form section 12. This reduces the overall number of form panels required and requires no adjustment of the panels to adapt them for use in the horizontal section 12. The panels from the vertical section 10 are secured to the intermediate section 14 to form the horizontal section 12 in the same manner as previously described when separate panel sections comprise the horizontal form 12. The concrete ceiling (or floor) 44 is immediately poured onto the horizontal form 12. The concrete-engaging ledger members 28 prevent the intermediate section 14 from sliding down the wall 30 and thereby permit the section 14 to support the ends of the horizontal form sections 12. The fact that the vertical leg of the L-shaped intermediate section 14 is approximately twice the length of the horizontal leg results in transfer of the forces acting upon the wall 30 to a point away from the uppermost part of the wall thereby eliminating much of the strain on the weakest portion of the wall and allowing a much greater weight to be supported by the intermediate section 14. It is also to be noted that the respective legs of the V-shaped ledger member 28 are disposed at a right angle relative to each other thereby resulting in maximum radial distribution of the weight from the horizontal section 12 through the concrete wall 30. The fact that spanner 20 interconnects the inner element 24 and the outer element 26 and extends through the concrete wall 30 also helps to distribute the forces imposed on the intermediate section 14 over a relatively large area of the wall 30. It is, of course, well known that the compression strength of a concrete structure is much greater than its tensile strength and by interconnecting the inner and outer elements 24 and 26 through the spanner 20 a portion of the load on the inner element 24 is transferred to the element 26 to act as a compression force on the concrete wall 30. The same is true with regard to the load carried by the outer element 26.

When the intermediate form section 14 is properly placed on either side of the concrete wall 30 a perfect corner between the wall 30 and the ceiling 44 is assured and this corner will not be disturbed in any way when the intermediate section 14 is removed. It is also possible, through use of the invention, to correct minor deformations in the vertical walls 30 which have occurred during the initial setting up period of the concrete because of shrinkage of the latter by placing the horizontal section 12 in between the intermediate sections 14 on adjacent walls 30 and then drawing the intermediate sections 14 toward the horizontal section 12 until the two are in abutting relationship. This may be achieved by a conventional nut-and-bolt assembly (not shown) inserted through one of the openings in which the pin assemblies 22 are normally disposed. This corrective action is possible because the intermediate sections 14 are capable of supporting the horizontal form sections 12 even before the concrete wall 30 has fully set up.

Once the concrete ceiling 44 has set up sufficiently the pin assemblies 22 connecting the intermediate section 14 and the horizontal section 12 are removed thereby permitting removal of the aforementioned form sections. As illustrated in FIG. 5, the ledger member 28 leaves a V-shaped depression 48 in the finished wall 30. Although the depression 48 normally does not detract from the appearance from the finished wall 30, and in fact may be considered to enhance its appearance, this depression may be grouted closed when it is desired to have an uninterrupted planer surface. It is also to be understood that while external vertical supports 40 and 42 have been illustrated in the drawing as providing supports for the horizontal form section 12, this external support is not essential to the use of the present invention and in those cases where the distance between adjacent walls 30 is only a few feet these external supports are not required.

Claims

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a concrete wall and ceiling form wherein both vertical and horizontal form sections are utilized, the improvement comprising:

an intermediate form section,

said intermediate section having horizontal and vertical segments configured to abut said horizontal and vertical sections respectively,

said vertical segment being provided with inwardly projecting concrete-engaging ledger means for supporting said horizontal section after removal of said vertical section from the wall; and

means for coupling said intermediate section to said vertical section and to said horizontal section.

2. The invention of claim 1, wherein said ledger means comprises a V-shaped member integral with said vertical segment.

3. The invention of claim 2, wherein the respective legs of the V-shaped member are disposed at a right angle relative to each other.

4. The invention of claim 1, wherein said intermediate section comprises an L-shaped member and the respective legs of said member form said horizontal and vertical segments.

5. The invention of claim 4, wherein the leg of said member forming said vertical segment is at least twice the length of the leg of said member forming said horizontal segment.

6. The invention of claim 1, wherein said vertical form section comprises an inner portion disposed in spaced interconnected relationship to an outer portion, and said intermediate section comprises an inner element disposed in spaced interconnected relationship to an outer element, each of said elements having ledger means thereon for supporting an adjacent horizontal form section when the respective inner and outer portions of the vertical form section are removed from the wall.

7. The invention of claim 6, wherein said ledger means on the respective inner and outer elements are disposed in opposed relationship in the same horizontal plane.