METHOD AND APPARATUS FOR FORMING A FORMWORK FOR A CONCRETE SLAB

• US 20160115698A1
• Filed: 06/05/2014
• Published: 04/28/2016
• Est. Priority Date: 06/05/2013
• Status: Active Grant

• Current Assignee: Fabio Parodi
• Original Assignee: Fabio Parodi
• Inventors: Parodi, Fabio
• Granted Patent: US 10,066,404 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E04B 5/21 Cross-ribbed floors
• CPC Class Codes: E04B 5/36 with form units as part of the floor
• CPC Class Codes: E04C 5/168 Spacers connecting parts for reinforcements and spacing the reinforcements from the form
• CPC Class Codes: E04G 11/46 of hat-like or trough-like shape encasing a rib or the section between two ribs or encasing one rib and its adjacent flat floor or ceiling section for separately encased beams E04G13/04
• CPC Class Codes: E04G 15/061 Non-reusable forms positioning means without forming function E04G21/185; electric distribution boxes H02G3/08
• CPC Class Codes: E04G 17/00 Connecting or other auxiliary members for forms, falsework structures, or shutterings
• CPC Class Codes: E04G 9/021 the form surface being of cardboard
• CPC Class Codes: E04G 9/086 which are specially adapted to be degradable in time, e.g. by moisture or water

Abstract

A method and apparatus for forming a formwork for a ribbed or waffle concrete slab is provided. The apparatus includes a rectangular block having a ledge around the base, the ledge having a dimension of half the desired width of the base ribs of the concrete slab, and a keystone connector. The keystone connector has an engagement portion configured to attach to an engagement portion on each block. In a method, the blocks are laid out so that the ledges of adjacent blocks are in contact. A keystone connector is then placed at each intersection of four blocks by attaching the respective engagement portions of the keystone connector and each block so that the keystone connector holds each of the four blocks in place relative to one another. The keystone connector is also configured to retain a reinforcing rod laid in the channel between adjacent blocks.

Claims

1-20. -20. (canceled)

21. A method of forming a formwork for a concrete slab using hollow blocks having a top, four sides, and a ledge extending from each side of the block along an edge of the block distal to the top of the block, the ledge forming a base for the block, the method comprising:

placing the blocks adjacent one another on the site where the slab is to be formed;

fitting a keystone connector at each intersection of four adjacent blocks; and

placing a reinforcing rod into the space between the adjacent blocks such that the reinforcing rod is retained by the keystone connector at the intersection, wherein

the keystone connector is configured to attach to each of the four blocks at the intersection and to hold them in place relative to one another such that at least a portion of an edge of a ledge of one block is in contact with at least a portion of an edge of a ledge of an adjacent block.

22. The method of claim 21, wherein

the keystone connector comprises a keystone engagement portion having a resilient barb on a pin, and

the block comprises a block engagement portion comprising an aperture having a lateral dimension less than a lateral dimension of the pin and resilient barb together, the aperture located in the vicinity of a corner of the block near the base, wherein

the step of fitting the keystone connector comprises:

pushing the pin of the engagement portion of the keystone into the aperture in the block engagement portion such that the resilient barb deforms on entry into the aperture and returns to its original form when the keystone engagement portion is fully engaged with the aperture inside the hollow block, thus retaining the keystone engagement portion in the block engagement portion, and

repeating this step for all blocks at the intersection.

23. A keystone connector for use in forming a formwork for a concrete slab using an arrangement of hollow blocks, each block having a top and four sides and a ledge extending from each side of the block along an edge of the block distal to the top of the block, the ledge forming a base for the block, wherein

the keystone connector comprises four engagement portions, each engagement portion configured to attach to a block engagement portion of one or other of the four blocks at an intersection of four adjacent blocks and to hold them in place relative to one another with at least a portion of the ledge of each block at the intersection in contact with at least a portion of an edge of the ledge of an adjacent block at the intersection,

each engagement portion of the keystone connector is configured to attach to one of the block engagement portions so that the keystone is locked onto the block, and

the keystone connector comprises a retaining portion configured to retain a reinforcing rod.

24. The keystone connector of claim 23, wherein

the keystone engagement portion comprises a pin with a resilient barb in the vicinity of an end of the pin, and

the resilient barb is configured to deform when the keystone engagement portion is pushed into the block engagement portion and to return to its original shape when the keystone engagement portion is fully attached to the block engagement portion.

25. The keystone connector of claim 23, wherein

the keystone connector comprises two pairs of retaining portions, and

one of the pairs of retaining portions is oriented orthogonally to the other pair of retaining portions.

26. The keystone connector of claim 25, wherein a pair of retaining portions is configured to retain a reinforcing bar.

27. The keystone connector of claim 23, wherein the retaining portion is oriented to retain a reinforcing bar placed into the space between two adjacent blocks in the arrangement of blocks.

28. The keystone connector of claim 23, wherein the retaining portion comprises a guide portion configured to guide a reinforcing rod into a groove of the retaining portion.

29. The keystone connector of claim 28, wherein the retaining portion comprises a retainer in the form of a pair of resilient barbs located at an entry to the guide portion, the barbs configured to deform to allow a reinforcing rod to enter the guide portion and to revert to their original shape after the reinforcing rod is passed the barbs, thus retaining the reinforcing bar in the retaining portion.

30. A hollow block for use with a keystone connector in forming a formwork for a concrete slab, wherein

the keystone connector comprises:

an engagement portion configured to attach to the block, and

a retaining portion configured to retain a reinforcing rod, the block having a top and four sides and a ledge extending from each side of the block along an edge of the block distal to the top of the block, the ledge forming a base for the block, and

the block comprises a block engagement portion having an aperture configured to engage with the keystone engagement portion to attach the block to the keystone connector.

31. The hollow block of claim 30, wherein each side of the block comprises indentations that form two arches oriented orthogonally to one another.

32. The hollow block of claim 30, wherein each corner of the block comprises a slot.

33. The hollow block of claim 32, wherein the slot extends from at or near the base of each corner to the top of the block.

34. The hollow block of claim 32, wherein a base of the slot is oriented at 45°

with respect to the base of the block.

35. The hollow block of claim 30, wherein the hollow block is formed from a molded high density pulped cardboard slurry.