Patent Application
20100162656
A concrete slab is a common structural element of modern buildings. Horizontal slabs of steel reinforced concrete, typically between 10 and 50 centimetres thick, are most often used to construct floors and ceilings, while thinner slabs are also used for exterior paving.
In many domestic and industrial buildings a thick concrete slab, supported on foundations or directly on the sub soil, is used to construct the ground floor of a building. In high rises buildings and skyscrapers, thinner, pre-cast concrete slabs are slung between the steel frames to form the floors and ceilings on each level.
A concrete slab may be prefabricated or cast in situ. Prefabricated concrete slabs are built in a factory and transported to the site, ready to be lowered into place between steel or concrete beams. They may be pre-stressed (in the factory), post-stressed (on site), or unstressed. It is vital that the supporting structure is built to the correct dimensions, or the slabs may not fit.
In situ concrete slabs are built on the building site using formwork—a type of boxing into which the wet concrete is poured. If the slab is to be reinforced, the rebars are positioned within the formwork before the concrete is poured in. Plastic tipped metal, or plastic bar chairs are used to hold the rebar away from the bottom and sides of the formwork, so that when the concrete sets it completely envelops the reinforcement. For a ground slab, the formwork may consist only of sidewalls pushed into the ground. For a suspended slab, the formwork is shaped like a tray, often supported by a temporary scaffold until the concrete sets.
The formwork is commonly built from wooden planks and boards, plastic, or steel. On commercial building sites today, plastic and steel are more common as they save labour. On low-budget sites, for instance when laying a concrete garden path, wooden planks are very common. After the concrete has set the wood may be removed, or left there permanently.
In some cases formwork is not necessary—for instance, a ground slab surrounded by brick or block foundation walls, where the walls act as the sides of the tray and hardcore acts as the base.
When shear bolts are embedded in a concrete slab, they must be supported during the concrete pour. When shear bolts are needed away from the edges of a concrete slab, they must be supported on the underlying surface. The present invention is a free-standing anchor bolt holder that holds an anchor bolt upright during the concrete pour. If necessary, the anchor bolt holder can be fastened to the material of the underlying surface.
An object of the present invention is to provide a connection between an anchor bolt and an anchor bolt holder that is economically efficient to produce and simple to use. This object is achieve by forming the anchor bolt holder from sheet metal and shaping the anchor bolt holder so that it can be formed on an automated die with a minimum of unused material.
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Preferably, the majority of the first foot 2 is substantially planar, and the majority of the second foot 17 is substantially planar. The outer edge 4 of the first foot 2 preferably has first, second and third substantially linear side portions 30, and the outer edge 19 of the second foot 17 has first, second and third substantially linear side portions 30. Preferably, the first foot 2 has a fastener opening 31; the second foot 17 has a fastener opening 31.
The first foot 2 and the second foot 17 preferably are substantially horizontally-oriented. Preferably, the first side member 5 and the second side member 11 are substantially vertically-oriented.
Preferably, as shown in
The anchor bolt connection 101 preferably comprises a sheet metal anchor bolt holder 1 and an anchor bolt 102. The sheet metal anchor bolt holder 1 preferably has a first foot 2, a first side member 5, a second side member 11, a second foot 17, and a plurality of arched rib bands 16 that connect the first side member 5 and the second side member 11.
Preferably, the first foot 2 has an inner edge 3 and an outer edge 4. Preferably, the first side member 5 has a bottom edge 6, an inner side edge 7, an outer side edge 8, and a top edge 9. The first side member 5 preferably is integrally joined to the first foot 2 along a first bend 10 at least partially coincident with the bottom edge 6 of the first side member 5 and the inner edge 3 of the first foot 2.
Preferably, the second side member 11 has a bottom edge 12, an inner side edge 13 facing the inner side edge 7 of the first side member 5, an outer side edge 14 facing away from the outer side edge 8 of the first side member 5, and a top edge 15. The second side member 11 preferably is integrally joined to the first side member 5 by a plurality of arched rib bands 16. Preferably, the second foot 17 has an inner edge 18 and an outer edge 19. The second foot 17 preferably is integrally joined to the second side member 11 along a second bend 20 at least partially coincident with the bottom edge 12 of the second side member 11 and the inner edge 18 of the second foot 17.
The arched rib bands 16 preferably each have a first end 21 and a second end 22, an upper edge 23 and a lower edge 24, a generally concave inner side 25 and a generally convex outer side 26. Preferably, the upper edge 23 and second lower edge 24 both extend from the first end 21 to the second end 22. The first end 21 preferably is integrally joined to the inner side edge 7 of the first side member 5 and the second end 22 being integrally joined to the inner side edge 13 of the second side member 11. Preferably, the arched rib bands 16 alternately arch in opposite directions to define an anchor-receiving space 27 encompassed by the generally concave inner sides 25. The anchor bolt 102 preferably has a first end portion 103 inserted in the anchor-receiving space 27 so that the anchor bolt 102 interfaces with the generally concave inner sides 25 of the arched rib bands 16.
Preferably, the first end portion 103 of the anchor bolt 102 is threaded. A first nut 104 preferably is threaded onto the first end portion 103 so that it contacts the sheet metal anchor bolt holder 1. The nut 104 increases the pullout resistance of the anchor bolt 102.
The outer faces 33 of the first foot 5 and the second foot 17 preferably interface with a structural support surface 105.
Preferably, the anchor bolt holder 1, the anchor bolt 102 and the nut 104 are embedded in a concrete structural member 106.
Preferably, the maximum width between the outer edge 4 of the first foot 2 and the outer edge 19 of the second foot 17 is 3 3/32 inches. The maximum height between the upward-facing inner faces 32 of the first and second feet 2 and 17 to the top edges 9 and 15 of the first and second side members 5 and 11 is preferably 3¼ inches. Preferably, the distance between the inner face 32 of the second foot 17 and the lower edge 24 of the nearest rib band 16 is 1¼ inches. The distance between the upper edge 23 and the lower edge 24 of each rib band preferably is ½ inch. Preferably, the anchor-receiving space 27 is generally cylindrical, with a diameter of approximately 1.125 inches. The distance between the outer side edges 8 and 14 of the first and second side member 5 and 11 to the middle of the nearest gusset 29 preferably is 11/16 inches. Preferably, the maximum distance from the inner edge 3 to the outer edge 4 of the first foot 2 is 1½ inches. Preferably, the maximum distance from the inner edge 18 to the outer edge 19 of the second foot 17 is also 1½ inches. The distance from the outer side edge 8 of the first side member 5 to the outer side edge 14 of the second side member 11 preferably is 3⅛ inches. Preferably, the distance from the outer side edges 8 and 14 of the first and second side members 5 and 11 to the middle of the adjacent stiffening embossments 28 is 5/16 inches. The distance from the outer side edges 8 and 14 of the first and second side members 5 and 11 to the inner side edges 7 and 13 where the rib bands 16 attach preferably is 27/32 inches. The inner side edges 7 and 13 are preferably parallel and relatively distantly spaced where the rib bands 16 attach, then colinear, than relatively closely spaced as they approach the bottom edges 6 and 12 of the first and second side members 5 and 11. The embossments 28 preferably begin at the top edges 9 and 15 of the first and second side members 5 and 11, and extend straight down 3.031 inches.
