Title:
Spring assembly for reshore posts
Kind Code:
A1


Abstract:
A metal reshore post for concrete forming systems is described. The reshore post includes an end plate to which is releasably attached a leaf spring. Clips formed in the leaf spring engage corresponding notches in the end plate. The spring retains the reshore post in its upright position during installation and prevents the reshore post from falling over upon release of the load.



Inventors:
Mccracken, Robert (Urbandale, IA, US)
Application Number:
11/433658
Publication Date:
11/15/2007
Filing Date:
05/12/2006
Primary Class:
International Classes:
E04H12/00
View Patent Images:
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Primary Examiner:
KWIECINSKI, RYAN D
Attorney, Agent or Firm:
DAVIS, BROWN, KOEHN, SHORS & ROBERTS, P.C. (DES MOINES, IA, US)
Claims:
I claim:

1. A metal reshore post of concrete forming apparatus, comprising: (a) a post member of adjustable height; (b) an end plate attached to the post member and having an first attachment structure; and (c) a spring having a second attachment structure releasably secured to the first attachment structure of the end plate.

2. A reshore post as defined in claim 1, wherein the first attachment structure of the end plate comprises a notch and wherein the second attachment structure comprises a clip releasably engaged to the notch.

3. A reshore post as defined in claim 1, wherein the spring is a leaf spring.

4. A reshore post as defined in claim 3, wherein the leaf spring comprises a web section having two sides and two ends and a pair of curved spring sections extended upwardly and outwardly from either side of the web section.

5. A reshore post as defined in claim 4, wherein the web section is in contact engagement with the end plate.

6. A reshore post as defined in claim 4, wherein the clip is formed on an end of the web section.

7. A reshore post as defined in claim 4, wherein the end plate includes a pair of spaced apart notches and wherein the spring includes a pair of spaced apart clips formed on either end of the web section and engaged one each to a corresponding one of the notches.

Description:

BACKGROUND OF THE INVENTION

The invention relates generally to concrete form apparatus and, more specifically, to spring assembly of a reshore post component of concrete form systems that retains the reshore post in its upright position upon unloading of the reshore post during disassembly of the concrete forms.

Concrete forming apparatus is in wide use in the construction of buildings, bridges, and other concrete structures. A common system for forming concrete structures uses a plurality of modular form components that are adapted to be assembled into a wide variety of configurations to conform to virtually any architectural requirement. Such forming apparatus components are typically made of metal so that they are strong enough to support the heavy weight of poured concrete and durable so that the components can be reused many times.

In the construction of concrete structures, for example multi-story buildings, it is common to pour floors in succession, starting at the bottom. Accordingly, concrete forming apparatus for pouring upper floors typically must be supported on the next lower floor. Economy and time of construction, however, often demands that the upper floors be poured before the concrete in the floors below has fully set. The concrete in the floor immediately below the floor being poured may not, therefore, have cured or hardened sufficiently to be strong enough to support the load of the concrete forming apparatus and plastic concrete used to form the floor being poured. It is common practice in such situations to insert shore posts below the insufficiently hardened floor or slab to distribute the load to one or more lower floors. The shore posts inserted below the partially hardened floors are generally referred to as reshore posts or just reshores. In typical applications there may be two or three levels of reshores below the shores supporting the fresh concrete.

After the new slab of fresh concrete has cured sufficiently, workers remove the shore posts and strip the formwork they supported. This removes the load on the reshore posts below. In some situations, the removal and stripping operation will cause a complete release of the reshore post, allowing it to fall over. This, of course, presents a risk of injury to workers in the area of the reshore posts. In the case of wood reshore posts, to prevent the reshores from being released, it is known to nail a leaf spring to the top of the reshore post. Even upon release of the load on the reshore post, the spring remains in a degree of compression and continues to hold the reshore post upright. Unfortunately, no spring systems are in use with metal reshore posts because of the difficulty of attachment to the metal. Accordingly, there is needed a spring assembly for use with metal reshore posts that will hold them in their upright position when the load is released.

SUMMARY OF THE INVENTION

The preferred embodiment of the present invention consists of a spring assembly of a metal reshore post used in concrete forming apparatus that will hold the reshore post in its upright position even after the load on the reshore post has been released. The assembly includes a spring that is releasably attached to an end plate secured to an end of the reshore post. The spring has a pair of clips that engage notches in the end plate to releasably secure the spring to the end plate. A variety of end plates may be used provided that appropriately spaced notches are formed in the plate. In a preferred embodiment, an end plate attached to what is most often the bottom end of the reshore post is of a different configuration from the end plate attached to the other end of the reshore post. The difference in configurations allows the reshore post to be used in both orientations in order to adapt to a larger variety of heights between floors.

An object of the present invention is to provide a spring assembly for metal reshore posts of concrete forming apparatus that continues to support the reshore post in an upright position after release of a load on the reshore post.

Another object of the present invention is to provide a spring assembly for metal reshore posts of concrete forming apparatus that may be releasably attached to either end of the reshore post.

These and other objects will be understood by those skilled in the art upon a review of this specification, the associated figures and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a reshore post representing a preferred embodiment of the present invention.

FIGS. 2a-d are schematic representations of four typical construction phases of a multi-story concrete structure showing the use of shores and reshores.

FIG. 3 is an enlarged perspective view of an end plate of a preferred embodiment of the present invention.

FIG. 4 is an enlarged perspective view of an end plate of an alternative preferred embodiment of the present invention.

FIG. 5 is an enlarged perspective view of leaf spring of a preferred embodiment of the present invention.

FIG. 6 is an enlarged view of the upper end of the reshore post of FIG. 1 showing the leaf spring attached to an end plate.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Illustrated in FIG. 1, generally at 10, is a reshore post representing a preferred embodiment of the present invention. The reshore post 10 includes an outer telescoping tube 12, an inner telescoping tube 14, a bottom end plate 16, a top end plate 18, and a leaf spring 20. The shore post 10 may be adjusted in length by telescopic movement of the inner tube 14 inside the outer tube 12. The shore post 10 may be set at a plurality of adjusted lengths by use of a pin 22 that is inserted into a pair of diametrically opposed holes 24 in the outer tube 12 and a selected pair of a plurality of holes 26 in the inner tube 14 spaced at a regular interval. Fine adjustment of the length of the shore post 10 is made by rotation of a threaded linkage member 28.

The reshore post 10 is used in the construction of concrete structures, for example multi-story concrete buildings. Shore posts are also typically used. Shore posts may take a large variety of configurations. For the purposes of this specification, suitable shore posts may be identical to the reshore post 10 with the exception that the leaf spring 20 is not used. Rather, the top end plate 18 is used to secure a different component of formwork, such as a drop head, support beam, form panel, or the like. In a typical construction cycle for a multi-story concrete building, a floor 30 is formed using reshore posts 10 supporting two lower stories and shore posts 32 and formwork 34 on which the slab of the floor 30 will be formed (FIG. 2a). Once the fresh concrete has hardened sufficiently to carry its own weight, the shores 32 and formwork 34 are removed (FIG. 2b). Frequently, the fresh concrete slab 30 will deflect or sag under its own weight. To pour the next floor, it will be necessary to install shore posts and formwork on the most recently poured floor slab 30, the strength of which may not be sufficient to support the load that will be imposed. To support further the most recently poured floor slab 30, the reshore posts 10 are cycled by removing them from two floors below (FIG. 2c) and installing them on the floor beneath the most recently poured floor 30 (FIG. 2d).

It is generally recommended that the reshore posts 10 be installed snugly under the slab or floor to be supported but relatively load free. Accordingly, the reshore posts 10 are adjusted to the approximate length that will allow the reshore 10 to be stood upright in position by use of the pin 22 in association with aligned pairs of holes 24 and 26, as described above. Once positioned, the height may be finely adjusted by turning of the threaded linkage member 28 to bring the leaf spring 20 into contact with the bottom of the floor to be supported and compressed sufficiently to hold the reshore post 10 in its upright position. Upon installation of the shore posts 32, formwork 34, and plastic concrete for the next story, the floor 30 is expected to deflect, further compressing the spring 20 until, most commonly, the floor 30 will be supported effectively on the top end plate 18.

When the most recent floor has set sufficiently to support its own weight, the shores 32 and formwork 34 are stripped. This will release the load from the reshores 10 as the floor 30 returns to its un-deflected position. The spring 20 will retain compressed contact with the bottom of the floor 30 throughout and so continue to hold the reshore post 10 in its upright position.

The top end plate 18 of a preferred embodiment has a generally rectangular shape (FIG. 3). Notches 36 and 38 are formed in opposite sides of the end plate 18. The bottom end plate 16 is substantially U-shaped in cross section, having a web 40 that is similar in shape to the top end plate 18, and a pair of flanges 42 and 44 formed on opposite sides of the web 40 (FIG. 4). The bottom end plate 16 is formed of a plate of steel that is bent to form the web 40 and flanges 42, 44. Rectangular holes 46 and 48 formed at the juncture of the web 40 and the flanges 42 and 44, respectively, form notches 50 and 52 upon bending of the bottom end plate 16.

The spring 20 of a preferred embodiment includes a flat web section 54 from either side of which extend outwardly and upwardly a curved spring section 56 and 58. Spring clips 60 and 62 are formed at opposite ends of the web section 54. The clips 60 and 62 include a modified S- or ogee-shaped end portion 64 and 66, respectively. In use, the spring 20 is releasably attached to the top end plate 18 by aligning spring clips 60, 62 with the notches 36, 38 and pressing to flex the spring clips 60, 62 outwardly so that they slide past the notches 50, 52 and bring the web section 54 into contact with the end plate 18. The end portions 64 and 68 of the spring clips 60, 62 engage the underside of the top end plate 18 to retain the spring 20 on the top end plate 18. If desired, the spring 20 can be readily removed by pulling outwardly on the spring clips 60 and 62. While the reshore post 10 is most commonly used with the top end plate 18 at the top, there are circumstances where it is advantageous to orient the reshore post 10 with the bottom end plate 16 at the top. Accordingly, in a manner similar to that discussed above with respect to the top end plate 18, the spring 20 may be releasably attached to the bottom end plate 16 by use of the notches 50 and 52.

The foregoing description and drawings comprise illustrative embodiments of the present inventions. The foregoing embodiments and the methods described herein may vary based on the ability, experience, and preference of those skilled in the art. Merely listing the steps of the method in a certain order does not constitute any limitation on the order of the steps of the method. The foregoing description and drawings merely explain and illustrate the invention, and the invention is not limited thereto, except insofar as the claims are so limited. Those skilled in the art that have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.