Floor structure

Abstract: A floor structure comprises a flooring (1) arranged on top of a lower and an upper layer of parallel joists (3-8 and 9-13, respectively) with a uniform mutual distance, the joists (3-8, 9-13) of one layer extending substantially perpendicular to the joists (3-8, 9- 13) of the second layer.The lower layer of joists (3-8) are arranged on chocking means (23, 24), at least one of said chocking means everywhere being provided below the centre between the upper joists (9-13) arranged thereabove. Resilient spring elements (14, 22) are provided at the intersections between the two layers of joists (3-8, 9-13). The layers of joists (3-8, 9-13) include prefabricated identical members (2) fitting in one another, and where each member comprises a predetermined number of joists. The joists (3-8) of the lower layer are equally long and project by half the joist distance of the upper layer of joists beyond the outermost joist (9,13) at the adjacent end of the upper layer of joists (9-13). The joists (9-13) of the upper layer are also equally long, but interconnected in such a manner that one end of some of the upper joists (9-13) ends substantially at the centre of a spring element (22) on the adjacent outermost joist (9-13) in the lower layer of joists (3- 8), and furthermore in such a manner that the corresponding end of the remaining upper joists (9-13) project beyond the adjacent outermost joist (3, 8) by a length substantially corresponding to the sum of the joist distance of the lower layer of joists and half the width of a lower joist (3-8) measured in the longitudinal direction of the upper joist.

Description: The invention relates to a floor structure comprising a flooring arranged on top of a first lower and a second upper layer of parallel joists, the joists of each layer being uniformly spaced and the joists of one layer extending substantially perpendicular to the joists of the second layer, and further the lower layers of joists being interconnected and arranged on top of chocking means, where at least one of said chocking means everywhere is provided substantially below the centre between the superposed joists of the upper layer, and where resilient spring elements are accommodated at the intersections between the two layers of joists. It is known from DK-A-168 453 to manufacture floor structures with a flooring of for instance parquet arranged on top of two layers of parallel joists, whereby the joists of one layer extend perpendicular to the joists of the other layer, and where resilient spring elements are provided between the two layers of joists at the intersections. The two layers of joists are supported on chocking means. Such a flooring is used for instance for the manufacture of sports floors. The object of the invention is to provide a floor structure which can be put down in a fast and easy manner. The floor structure according to the invention is characterised in that the two layers of joists are composed of prefabricated identical and mating members, and where each member comprises a predetermined number of joists, the joists of the lower layer being equally long and projecting by half the joist distance of the upper layer of joists beyond the outer joist at each adjacent end of the upper layer of joists, and the joists of the upper layer of joists being equally long, but staggered relative to one another in such a manner that one end of some of the upper joists ends substantially at the centre of a spring element on the adjacent outer joist in the lower layer of joists and further such that the corresponding end of the remaining upper joists projects beyond the adjacent outer joist by a length substantially equal to the sum of the joist distance of the lower layer of joists and half the width of a lowermost joist, measured in the longitudinal direction of an uppermost joist. The resulting floor structure is relatively easy to put down. The latter is especially due to the fact that the individual members are easily prefabricated and then put down in situ merely by joining the members with the joists of each layer extending in extension of one another, and without necessitating a direct fastening of the members to one another. According to the invention it is particularly preferred that the said at least one chocking means below the lower joists has been fastened in advance to the joists of each member, a chocking means also being fastened to the ends of the lower joists of each member. In order to ensure a particularly good resilience in the floor structure, the top side of the joists of the lower layer of joists of each member may be provided with a vertical, transverse slot substantially centrally between each pair of adjacent joists in the upper layer of joists. A particularly good resilience is obtained when the joists are formed by layers of spruce plywood glued together in parallel. According to the invention the spring elements may be solid blocks of a rubber material of a rectangular shape when seen from the top as said spring elements are of a width substantially corresponding to half the joist width in the lower layer of joists at all the intersections apart from the intersections where the upper joists of each member end, while the remaining rubber blocks are of a substantially twice as large width. In this manner a good, resilient support is ensured of all the upper joists. Finally according to the invention, each rubber block may on the top side comprise a recess at each end for the fastening to the lower joists, and at least each of the narrow rubber blocks may comprise a central through opening allowing passage of a screw during the fastening of the remaining joists on the lower joists, whereby a particularly easy and fast manufacture of the prefabricated members is obtained. The invention is explained in greater detail below with reference to the accompanying drawing, in which Figure 1 is a vertical sectional view through a floor structure according to the invention, whereby only a single member of joists is shown, seen from the side, Figure 2 is a top view of a joist member, Figure 3 is a side view of an embodiment of a spring element, Figure 4 is a top view of the same embodiment, Figure 5 shows a screw for the securing of the joists at the intersections. The floor structure shown in Figure 1 comprises a flooring 1, which is secured in a conventionally known manner on top of two layers of joists. The layers of joists comprise a plurality of identical joist members designated the general reference numeral 2 and of which only a single member appears from Figure 1. These joist members are arranged either directly on a sub-floor or spaced from said sub-floor by chocking means known per se and not shown in greater detail. As illustrated in Figure 2, a joist member 2 comprises a first lower layer of parallel joists 3, 4, 5, 6, 7 and 8 with the same mutual distance I 1 . These lower joists 3-8 are of the same length and arranged with aligned ends in such a manner that together they cover a surface formed as a rectilinear rectangle. A second, upper layer of joists 9, 10, 1 1, 12, and 13 is placed on top of the lower layer of joists 3-8. These upper joists 9-13 are also arranged in parallel and with the same mutual distance 12, said upper joists 9-13 extending perpendicular to the lower layer of joists 3-8. The outermost arranged joists 9 and 13 of the upper layer are arranged at a distance corresponding to half 12/2 their mutual distance from the respective ends of the lower joists 3-8. All the joists in the lower layer of joists are of a width a, and all the joists of the upper layer of joists are of a width b. In the illustrated embodiment of the invention, the width a and the width b are identical. The outermost joists 9 and 13 of the upper layer of joists 9-13, are, as mentioned, arranged at a distance from the respective ends of the lower joists 3-8 which corresponds to half their joist distance 12, and thus the projecting ends of the lower joists 3-8 are of a length I 2 /2. The upper layer of joists -9-13 are furthermore staggered relative to one another in such a manner that adjacent one outermost joist 3 of the lower layer of joists 3-8 they are positioned alternately immediately above the centre of the joist 3 therebelow and project beyond said joist by a length corresponding to the sum of the joist distance I 1 in the lower layer of joists 3-8 and half the joist width a/2 of the lower joists 3-8. A spring element 14 of the type shown in Figures 3 and 4 is provided at the intersections between all the joists 3-8 and 9-13 apart from at the sites where the uppermost joists 9-13 end directly above a lowermost joist 3 and 8, respectively. These spring elements are indicated in black colour both in Figure 1 and in Figure 2. They comprise a rubber block, which in the preferred embodiment is made of a rubber material sold under the Trade Mark SYLOMER V-grey and of a density of 650 kg/m 3 . This rubber material is formed as a mat, and the members shown in Figures 3 and 4 are cut out thereof in the desired shape. At the ends a recess 15, 16 formed as a step is provided for the fastening of the spring members to the lowermost joists 3-8 by means of clamps or other fastening means. A through opening 17 is provided in the centre of the spring element, said opening be used during the fastening of the upper joists 9-13 to the lower joists 3-8. This fastening is suitably performed by means of screws 18 of the type shown in Figure 5. These screws comprise a head 19 and a thread 20 spaced by a smooth intermediary shaft 21. The fastening of the upper joists 9-13 to the lower joists 3-18 involves a drilling of through holes for the screws 18 in the upper joists 9-13. Subsequently, the screws 18 are inserted through these holes (not shown) and the openings 17 in the spring elements 14 and screwed into the lower joists 3-8, the thread 20 being positioned within the area of the lower joists 3-8 after the final mounting. Spring elements 22 are provided at the intersections where the ends of the upper joists 9-13 are positioned centrally on top of one of the outermost joists 3 and 8 in the lower layer of joists 3-8. The spring elements 22 are also indicated in black colour in Figures 1 and 2 and correspond completely to the elements 14 shown in Figures 1 and 2 apart from the fact that they do not comprise a through hole for the receiving of a screw. In addition, they are shaped with a width slightly exceeding the width of the spring elements 14 as they are of a width mating the width a of the lower joists 3-8. A chocking means 23 is provided everywhere on the bottom side of the lower joists 3-8 centrally between the upper joists 9-13. This chocking means is made of chipboard material and secured by means of clamps. Corresponding chocking means 24 are fastened at the ends of the lower joists 3-8. The chocking means 24 are here rather long in the longitudinal direction of the joist 3-8 in question. A transverse slot 25 is shaped everywhere at the centre between the upper joists 9-13 and directly above the chocking means 23, said slot extending downwards from the top side of the lower joists 3-8. The latter applies to all joists of a coefficient of rigidity E x I in the range of 250 x 10 6 to 1200 x 10 6 Nmm 2 , where E is the modulus of elasticity and I is the moment of inertia. In use, the joist members 2 are arranged so as to abut one another in such a manner that the lower layers of joists 3-8 extend in extension of one another, and such that the upper layers of joists 9- 13 also extend in extension of one another. As a result, the projecting ends of the upper joists 9-13 are resting on top of the spring elements 22 of the adjacent members, and the projecting ends of the abutting joist members are arranged on top of the spring elements 22 on the joist member 2 shown. The joist members are retained in position without further fastening to one another by being completely adjusted along the sides of the area on which the floor is to be put down. It can be necessary to cut off parts of the joist members 2. According to a preferred embodiment, the lower joists are of a length of 2,055.5 mm, while the upper joists are of a length of 1,800 mm. The number of lower joists is six while the number of upper joists is five. All the joists are of a cross section with a width of 51 mm and a height of 21 mm. The joists are made of spruce plywood glued in parallel and including seven layers of a thickness of 3 mm each. The joists are manufactured by cutting out prefabricated plates in the desired dimensions. The spring elements 14 are of a width of 25 mm, a length of 76 mm and a height of 12 mm. The remaining spring elements 22 are of the same length and height, but of a width of 51 mm which corresponds to the width of the joists. The slots 25 in the lower joists 3-8 are of a depth of 12 mm. The chocking means 23 in the area between the upper joists 9-13 present the dimensions 9 x 35 x 51 mm, whereas the chocking means provided at the ends present the dimensions 9 x 51 x 51 mm. By placing a flooring of boards of beech of the dimensions 22 x 129 mm on top of such means and nailing them to the joist members, it is possible to manufacture a floor structure meeting the required DIN-stand-ard 18032, part II. presented to sports floors. The invention has been described with reference to a preferred embodiment. Many modifications can be carried out without thereby deviating from the scope of the invention as described by the appended claims. The number of joists in each layer can for instance be changed, and the dimensions indicated can be changed as well.

Claims: A floor stucture comprising a flooring (1) arranged on top of a first lower (3-8) and a second upper layer (9-13) of joist, the joist (3-8, 9-13) of each layer being parallel and uniformly spaced and the joist (3-8, 9-13) of one layer extending subtantially perpendicular to the joist (3-8, 9-13) of the second layer, and further the lower layers of joists (3-8) being interconnected and arranged on top of chocking means (23, 24), where at least one said chocking means everywhere is provided subtantially below the centre between the superposed joists (9-13) of the upper layer, and where resilient spring elements (14, 22) are accommodated at the intersections between two layers of joists (3, 8 and 9-13), characterised in that the two layers are composed of prefabricated identical and mating members (2), and where each member (2) comprises a predetermined number of said joists, the joists (3-8) of the lower layer being equally long and projecting by half the joist distance (I 2 ) of the upper layer of joists beyond the outermost joist (9, 13) ar each adjacent end of the upper layer of joist (9- 13), and the joists (9-13) of the upper layer of joists being equally long, but staggered relative to one another in such a manner that one end of some of the upper joists (9-13) ends substantially at the centre of a spring element on the adjacent outer joist (3, 8) in the lower layer of joists (3-8) and further such that the corresponding end of the remaining upper joists (9-13) projects beyond the adjacent outer joist (3, 8) by a length subtantially equal to the sum of the joist distance (I 1 ) of the lower layer of joists and half the width (a) of a lowermost joist (3-8), measured in the longitudinal direction of an uppermost joist (9-13). A floor structure as claimed in claim 1, characterised in that the said at least one chocking means (23, 24) below the lower joists (3-8) is fastened to the joists (3-8) of each member (2), a chocking means (24) also being fastened at the ends of the lowermost joists of the each member. A floor structure as claimed in claim 1 or 2, characterised in that a vertical transverse slot (25) is provided on the top side of the joist (3-8) in the lower layer of joists of each member(2), such a slot being substantially centrally provided between each pair of adjacent joists (9-13) in the upper layer of joists. A floor structure as claimed in claim 1, 2, or 3, characterised in that the joists (3-13) are made of layers of spruce plywood glued together in parallel. A floor structure as claimed in claim 1, 2, 3, or 4, characterised in that the spring elements (14, 22) are solid blocks of a ruber material of a rectangular shape when seen from the top, as said spring elements (14) are of a width substantially corresponding to half the joist width (a/2) in the lower layer of joists at all the intersections apart from the intersections where the upper joists (9-13) of each member (2) end, while the remaining rubber blocks (22) are of a substantially twice as large width. A floor structure as claimed in claim 5, characterised in that on the top side each rubber block (14, 22) comprises a recess at each end to be used for the fastening to the lower joists, and that at least each of the narrow rubber blocks comprises a central through opening (17) for allowing passage of a screw during the fastening of the uppermost joists (9-13) to the lowermost joists.

Inventors: JORGENSEN CARL JORGEN SKOVBO, SLOTT OLE, JORGENSEN, CARL JORGEN SKOVBO, SLOTT, OLE
Applicants: JUNCKERS AS, JUNCKERS INDUSTRIER A/S
Application year: 1995
Main classification: E04F15
IPC codes: E04F15