The present invention relates generally to the field of flooring including wood laminate flooring, such as high density fiberboard (HDF) laminate flooring and medium density fiberboard (MDF) laminate flooring, solid wood flooring and engineered wood flooring, which includes a plurality of wood layers. More particularly, the present invention relates flooring having locking edge profiles
Floor covering panels, including wood laminate flooring, solid wood flooring and engineered wood flooring are well known in the prior art. To increase the ease of installation by removing the need for glues or adhesives, these floor coverings have been made with locking edges having a tongue with a projection and a groove with a corresponding depression in the core of the floor covering panel that together form coupling parts or means, which prevents substantial movement perpendicular to the major surfaces of the laminate flooring and perpendicular to the locking edges. In some embodiments the projection may be in the groove and the corresponding depression in the tongue.
Earlier locking laminates had locking edges on all four sides of the laminate. While installation of these laminates was easier than prior laminates that required the edges to be glued, installation was somewhat cumbersome since previously laid laminate panels had to be angled away from the subfloor on which the laminate was laid to permit and an additional panel to lock into place.
To overcome this problem, a lock and fold or lock and drop laminate was developed in which two of the opposite long edges had the standard locking profile in the core and the other two short opposite edges had a profile in the core, such as shown in
This worked well for laminate panels of about 3½ inches in width. However, due to the surfaces of the short lock and fold edges which engage each other being vertical, the flooring elements not being substantially urged together, the dimensions of panels, particularly the thickness of the panel, the depth of the depression and the height of the projection, and the cushion effect of the underlayment between the laminate and the substrate, the joints at the short lock and drop edges of wider panels, such as 5 inch wide and greater widths, tend to disengage when the laminate was stepped upon near the short edge. This causes ridges to form in the upper horizontal surface between the laminate panels resulting in an uneven walking surface.
Palsson et al. U.S. Pat. No. 7,121,058 discloses a flooring material with conventional locking profiles on two opposite edges. The other two opposite edges are a male vertical assembly joining member and a female vertical assembly joining member which mate by only vertical motion. The male vertical assembly joining member includes an inclined lower cheek surface and at least one snapping hook. The female vertical assembly joining member includes an inclined upper cheek surface and at least one under cut.
On assembly, the snapping hook and under cut interact to prevent the floor elements from disengaging vertically. The lower and upper inclined cheek surfaces engage to prevent the elements from disengaging horizontally. The inclined cheek surfaces also urge the floor elements together, which prohibit disengagement of the snapping hook and under cut without substantial damage to the snapping hook and/or under cut.
The present invention overcomes this problem by controlling the friction between the short edges of adjacent installed laminate panels. The friction is small enough to permit easy installation, i.e. requiring a minimum of pressure near the short edge during installation to engage the coupling parts, while being sufficiently great to deter disengagement during normal use when the installed panel is step on near the short end. However, the structure of the present lock and fold edge permits the laminate panels to be disengaged and reassembled, at least a number of times, without permanent damage to the lock and fold edges resulting in the loss of the desired friction.
Various embodiments are shown in the enclosed drawings. These include a small projection and groove feature on one or two vertical surfaces (perpendicular to the major, or upper and lower, surfaces of the laminate panel) of the second opposed side edges that are folded into engagement. The profile of the small projection and groove can be rectangular or rounded or an elongated projection. The projection can be formed as one panel from the coupling projection or groove, or be adhered to the vertical surface of the second opposed side edges.
In another embodiment, the projection can have a flat surface parallel to the upper surface of the laminate on the side of the projection toward the upper decorative surface and a curved surface opposite the flat surface. The curved surface reduces the pressure necessary to engage the short ends of the laminate panels and the flat surface, which engages a corresponding flat surface in the surface of the corresponding second side edge, increases the pressure necessary to disengage the panels.
Rather that a small projection and groove, the vertical or perpendicular surfaces of the second opposed side edges can be roughened, such as by a saw tooth profile or the application of a particulate containing composition. In another embodiment, a pressure sensitive adhesive can be applied to one or both of the adjacent perpendicular surfaces of the second opposed side edges.
The disengaging pressure can also be increased by modifying the horizontal surfaces (surfaces parallel to the upper surface of the laminate). A hook material can be adhered to one horizontal surface on one of the second opposed side edges and a loop material adhered to the corresponding adjacent side edge.
In another embodiment, the hook and loop material can be replaced with a pressure sensitive adhesive on one or both of the surfaces parallel to the upper surface of the laminate panel. In still another embodiment, one parallel surface may have a wedge projecting from the surface with the distal portion of the wedge having a greater cross-section than the portion adjacent the surface, and the adjacent parallel surface may have a correspondingly shaped groove. In yet another embodiment, the projection from the parallel surface can be in the shape of an arrowhead and the corresponding groove may have a simple rectangular cross-section.
In one embodiment, one or more of the surfaces perpendicular to the upper surface of the laminate panel may have an “S-shaped” or double-curved profile. If the double-curved profile intersects the upper or lower surfaces of the laminate, it may be beveled to deter damages as the panels are engaged.
Other profiles are also shown. The key features in some embodiments are that at least one pair of the corresponding surfaces of second two opposed edges are perpendicular to the upper surface and the corresponding perpendicular surfaces are non-planar, whereby one of the corresponding surfaces engages the other corresponding surface and the pressure to engage and disengage the laminate panel is increased slightly. In other embodiments corresponding surfaces parallel to the upper decorative surface have features that increase the force to disengage the panels. One of ordinary skill in the art can determine, without undue experimentation, the dimensions and tolerances necessary to permit easy installation, while deterring disengagement during normal use.
The upper lip locking projection 6 is formed on the upper lip 8 of the short side of panel 4 between the distal end 9 and the upper lip proximal groove 10. The upper lip proximal groove 10 is formed between the upper lip locking projection 6 and the body of the panel 4 adjacent the lower surface 11. The upper lip 8 includes an upper lip distal contact surface 12 and an upper lip proximal contact surface 14. The upper lip distal contact surface 12 is adjacent the upper decorative surface 13. The upper lip proximal contact surface 14 is between the lower surface 15 of the upper lip locking projection 6 and the upper surface 10″ of the upper lip proximal groove 10. The upper lip contact surfaces 12 and 14 are substantially perpendicular to the upper decorative surface 13.
The lower lip locking groove 7 is formed on the lower lip 16 of the short side of panel 3 between the lower lip distal projection 17 and the body of the panel 3 adjacent the upper decorative surface 13. The lower lip 16 includes a lower lip proximal contact surface 18 and a lower lip distal contact surface 19. The lower lip proximal contact surface 18 is adjacent the upper decorative surface 13. The lower lip distal contact surface 19 is between the lower surface 20 of the lower lip locking groove 7 and the upper surface 21 of the lower lip distal projection 17. The lower lip contact surfaces 18 and 19 are substantially perpendicular to the upper decorative surface 13.
The fold joint on the short side of panels 3 and 4 can be freely engaged, disengaged and reengaged. However, if the panels 3 and 4 are greater then 3.5 inches in width, they tend to disengage when the laminate was stepped upon near the short edge, particularly if the panels are laminate panels. This causes ridges to form in the upper horizontal surface between the laminate panels resulting in an uneven walking surface.
The slanted contact surfaces 10′ and 19′ urge the panels 3′ and 4′ together. This ensures locking of the snapping hook 22 and under cut 23, but makes disengagement of the short side fold joint prohibitive without damaging the snapping hook 22 and/or under cut 23. Therefore, if the panels 3′ and 4′ are disengaged, they cannot be reengaged without loss of the desired force which deters ridges forming in the upper horizontal surface between the panels when one panel is stepped on near the fold joint. Therefore, if the panels are disengaged and reengaged an uneven walking surface results.
This problem is overcome in the present invention by keeping the contact surfaces substantially perpendicular to the upper decorative surface, while increasing and controlling the friction between the contact surfaces as the panels are engaged, disengaged and reengaged. The increased friction results from a number of different force increasing means shown in FIGS. 4 to 20.
In
The embodiment shown in
The locations of the small projections and small grooves in
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In
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The embodiment shown in
In the embodiments in which the force increasing means is located on the upper surface of the locking groove and the lower surface of the locking projection (
Number | Date | Country | |
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60748526 | Dec 2005 | US |