Patent Description:
Subfloors are known comprising wood based panels, such as particle boards, comprising tongue and groove joints which are configured to be glued.

<CIT> discloses a set of subfloor panels according to the preamble of claim <NUM>. Further sets of panels are known from <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

Embodiments of the present invention address a need to provide an improved subfloor and joint.

A set of subfloor panels in accordance with the invention is set out in claim <NUM>. Preferable features thereof are specified in the dependent claims.

Accordingly, embodiments of the present invention preferably seek to mitigate, alleviate or eliminate one or more deficiencies, disadvantages or issues in the art, such as the above-identified, singly or in any combination by providing subfloor panels comprising a joint which enables a faster assembling of the subfloor panels. Another embodiment of the invention is to provide subfloor panels with a joint with increased strength.

At least some of these and other objects and advantages that will become apparent from the description have been achieved by an aspect of the invention that includes a set of essentially identical subfloor panels comprising a joint configured to be glued. The joint comprising a tongue at a first edge of a first panel and a tongue groove at a second edge of a second panel. The tongue and the tongue groove are configured for positioning of the first panel relative the second panel in a vertical direction. A lower lip of the tongue groove extends beyond an upper lip of the tongue groove. An element protrudes from the lower lip and an underside of the first edge comprising an element groove. The element and the element groove are configured for positioning of the first panel relative to the second panel in a horizontal direction. An outer edge of the lower lip comprises a first impact surface, which is downward facing, and the first edge comprises a second impact surface, which is upward facing. The first impact surface is configured to cooperate with the second impact surface for partly absorbing a force applied at an upper surface of the first panel and/or at an upper surface of a second panel when the first and the second panel are joined by the joint and assembled on joists.

Thus, the joint solves the problem of positioning the first panel relative to the second panel before the glue dries or cures and bonds the first panel to the second panel.

The impact surfaces may have the effect that the strength of the joint is improved.

A lower surface of the tongue may be configured to be positioned at a distance from an upper surface of the lower lip, in a joined position of the first and the second panel such that a glue space is obtained.

The glue space may extend essentially from the element to an outer part of the tongue.

The distance between the lower surface of the tongue and the upper surface of the lower lip may be in the range of about <NUM>,<NUM> to about <NUM>,<NUM>, preferably about <NUM>,<NUM>.

An angle between the second impact surface and a lower surface of the first panel may be in the range of about <NUM>° to about <NUM>°, preferably about <NUM>°.

The first impact surface may be essentially parallel to the second impact surface.

The panels may be wood based panels, such as particleboard, OSB, plywood, HDF or MDF.

The first and the second panel may each comprise outer layers and a core layer, wherein the core layer comprises particles that are coarser than the outer layers, wherein the lower surface of the tongue and the upper surface of the lower lip are within the core layer, such that a stronger glue connection is obtained.

The first and the second panel may each comprise outer layers and a core layer, wherein the core layer comprises particles that are coarser than the outer layers, wherein an upper surface of the tongue is configured to be glued to a lower surface of the upper lip, wherein the upper surface of the tongue and lower surface of the upper lip, are within the core layer, such that a stronger glue connection is obtained.

The first impact surface and the second impact surface may be configured to be glued together.

The joint may be configured for a joining of the first edge and the second edge by an angling motion of the first panel relative to the second panel.

These and other aspects, features and advantages of which embodiments of the invention are capable of, will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which.

This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete.

The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to limit the invention. When the word "about" is used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of +/- <NUM>% around the stated numerical value.

An embodiment of the invention is shown in <FIG> in a 3D-view during assembling of a set of subfloor panels. The subfloor panels are essentially identical. An embodiment of a panel <NUM> in the set is shown in <FIG>. The panel <NUM> is of a rectangular shape and comprises a first edge 5a and an opposite second edge 5b. The panel <NUM> further comprises a third edge 4a and an opposite fourth edge 4b which extend between the first edge 5a and the opposite second edge 5b. The first and the second edge may be long edges and the third and the fourth edge may be short edges. The panel <NUM> comprises an upper surface <NUM> and at least two opposite edges comprise a joint for joining the panel <NUM> to an adjacent panel. <FIG> shows that a first edge 5a of a first panel <NUM>' may be joined to a second edge 5b of a second panel <NUM>" by an angling motion <NUM> and a third edge 4a of the first panel <NUM>' may be joined by the same angling motion to a fourth edge 4b of a third panel <NUM>. <FIG> shows a crosscut in a side view of an embodiment of the set of subfloor panels during joining and <FIG> shows the embodiment in a joined position. The set comprises a joint configured to be glued. The joint comprises a tongue <NUM> at a first edge 5a of a first panel <NUM>' and a tongue groove <NUM> at a second edge 5b of a second panel <NUM>". The tongue <NUM> and the tongue groove <NUM> are configured for positioning of the first panel <NUM>' relative to the second panel <NUM>" in a vertical direction.

A lower lip <NUM> of the tongue groove <NUM> extends beyond an upper lip <NUM> of the tongue groove <NUM>. An element <NUM> protrudes from the lower lip <NUM> and an underside of the first edge 5a comprises an element groove <NUM>, wherein the element and the element groove are configured for positioning of the first panel <NUM>' relative to the second panel <NUM>" in a horizontal direction. An outer edge of the lower lip <NUM> comprises a first impact surface <NUM>, which is downward facing, and the first edge 5a comprises a second impact surface <NUM>, which is upward facing. The first impact surface <NUM> is configured to cooperate with the second impact surface <NUM> for partly absorbing a force F applied at an upper surface <NUM>' of the first panel <NUM>' and/or at an upper surface <NUM>" of the second panel <NUM>" when the first and the second panel are joined by the joint and assembled on joists <NUM>, <NUM>' as shown in <FIG>.

<FIG> shows that glue <NUM>, <NUM>' may be applied on an upper surface <NUM> of the tongue <NUM> and on an upper surface <NUM> of the lower lip <NUM> before the first and the second panel are joined. Furthermore, glue may be applied on the first impact surface <NUM> and/or on the second impact surface <NUM> (not shown) before the first and the second panel are joined. The glue is, during the joining, distributed in parts of the joint. A portion of the glue may be positioned, in the joined positioned, at the upper surface <NUM>' of the first panel <NUM>' and/or second panel. That portion of the glue is preferably removed before the glue has dried or hardened.

The glue <NUM>' applied on the upper surface <NUM> of the tongue <NUM> may be distributed from an inner part <NUM> at the tip of the tongue <NUM> to an outer part <NUM> at the upper surface <NUM>',<NUM>" of the first panel <NUM>' and/or second panel <NUM>".

The joint may comprise a first joint surface <NUM> at the first edge 5a and an opposite second joint surface <NUM> at the second edge 5b. The first joint surface <NUM> extends from the upper surface <NUM>' of the first panel <NUM>' towards the tongue <NUM>. The second joint surface <NUM> extends from the upper surface <NUM>" of the second panel <NUM>' towards the tongue groove <NUM>. The first joint surface <NUM> and the opposite second joint surface <NUM> are configured to be glued to each other. The glue <NUM>' applied on the upper surface <NUM> of the tongue <NUM> may be distributed between the first joint surface <NUM> and the opposite second joint surface <NUM>.

A distance <NUM> between the first joint surface <NUM> and the second joint surface <NUM> may be in the range of about <NUM>,<NUM> to about <NUM>,<NUM>, or in the range of about <NUM>,<NUM> to about <NUM>,<NUM>, or about <NUM>,<NUM>.

The glue <NUM> applied on the upper surface <NUM> of the lower lip <NUM> may be distributed from an inner part <NUM> at the tip of the tongue <NUM> to an outer part <NUM> at the element <NUM>.

The glue may be a resin, preferably cross-linked, hot melt glue, white glue or glue comprising polyvinyl acetate or polyurethane.

A lower surface <NUM> of the tongue <NUM> may be configured to be positioned at a distance <NUM> from an upper surface <NUM> of the lower lip <NUM>, in a joined position of the first and the second panel <NUM>', <NUM>", such that a glue space is obtained. The glue space may extend essentially from the element <NUM> to an outer part of the tongue <NUM>. The distance <NUM> between the lower surface <NUM> of the tongue <NUM> and the upper surface <NUM> of the lower lip <NUM>, may be in the range of about <NUM>,<NUM> to about <NUM>,<NUM>, preferably about <NUM>,<NUM>.

A distance between the upper surface <NUM> of the tongue <NUM> and the lower surface <NUM> of the upper lip <NUM>, may be shorter than the distance <NUM> between the lower surface <NUM> of the tongue <NUM> and the upper surface <NUM> of the lower lip <NUM>.

An angle <NUM> between the second impact surface and a lower surface <NUM>' of the first panel <NUM>' may be in the range of about <NUM>° to about <NUM>°, preferably about <NUM>°.

The first impact surface <NUM> may be essentially parallel to the second impact surface <NUM>.

The first impact surface <NUM> and the second impact surface <NUM> may have a planar and/or curved shape.

The first impact surface <NUM> and the second impact surface <NUM> may have the same shape.

A distance <NUM> between the first impact surface <NUM> and the second impact surface <NUM> may be in the range of about <NUM>,<NUM> to about <NUM>,<NUM>, or in the range of about <NUM>,<NUM> to about <NUM>,<NUM>, or about <NUM>,<NUM>.

<FIG> shows that the first and the second panel <NUM>', <NUM>" each may comprise outer layers <NUM>, <NUM> and a core layer <NUM>, wherein the core layer <NUM> comprises coarser particles than the outer layers, wherein the lower surface <NUM> of the tongue and the upper surface <NUM> of the lower lip <NUM> is within the core layer, such that a stronger glue connection is obtained.

An upper surface <NUM> of the tongue <NUM> is configured to be glued to a lower surface <NUM> of the upper lip <NUM>, wherein the upper surface <NUM> of the tongue <NUM> and lower surface <NUM> of the upper lip <NUM>, is within the core layer <NUM>, such that a stronger glue connection is obtained.

The first impact surface <NUM> may be configured to be glued to the second impact surface <NUM>. The first impact surface <NUM> and the second impact surface <NUM> may be positioned at least partly in the core layer <NUM>. The glue <NUM>" between the first impact surface <NUM> and the second impact surface <NUM> may be distributed from a lower portion <NUM> at the lower surface <NUM>', <NUM>" of the first and the second panel, respectively, to an upper portion <NUM> adjacent to an upper surface of the element groove <NUM>.

Each of the panels may comprise a decorative layer attached to at least one of said outer layers.

<FIG> shows an embodiment of the first panel <NUM>', the second panel <NUM>" and the third panel <NUM> during assembling on joists <NUM>, <NUM>', <NUM>", <NUM>‴. The first panel <NUM>', the second panel <NUM>" and the third panel <NUM> may also be glued to the joists <NUM>, <NUM>', <NUM>", <NUM>‴. The joists <NUM>, <NUM>', <NUM>", <NUM>‴ may be wood based. The first panel <NUM>', the second panel <NUM>" and the third panel <NUM> may be identical.

<FIG> shows an embodiment of the joint for joining a third edge of the first panel <NUM>' to a fourth edge of a third panel <NUM>. The joint comprises a flexible tongue <NUM> at the fourth edge configured to cooperate with a tongue groove <NUM> at a third edge for positioning of the first panel <NUM>' relative to the third panel <NUM> in a vertical direction. The flexible tongue <NUM> may be positioned in a displacement groove <NUM>. The flexible tongue may be configured to be compressed during assembling and spring back towards and partly into the tongue groove <NUM>. The joint may comprise a strip <NUM> that protrudes from the fourth edge. An outer part of the strip <NUM> may comprise an element <NUM> and an underside of the third edge may comprise an element groove <NUM>, wherein the element and the element groove are configured for positioning of the first panel <NUM>' relative to the third panel <NUM> in a horizontal direction. <FIG> shows an embodiment of the joint comprising an embodiment of the displacement groove <NUM> which extends in an angled direction relative to an upper surface of the third panel. The joint is shown in a joined position. Glue may be applied in the joint before the fourth edge and the third edge are joined.

Embodiments of the flexible tongue <NUM>, which is displaceable in the insertion groove <NUM>, are shown in <FIG> show the flexible tongue <NUM> in a joined position and <FIG> show the flexible tongue <NUM> during assembling of a panel and an adjacent panel. <FIG> shows a cross section of the flexible tongue <NUM> in <FIG>, which shows a top view. <FIG> shows a cross section of the flexile tongue <NUM> in <FIG>, which shows a top view. The flexible tongue <NUM> comprises bendable protruding parts <NUM>. A space <NUM> is provided between the flexible tongue <NUM> and a bottom wall of the insertion groove <NUM>. <FIG> shows that the flexible tongue <NUM> is pushed into the insertion groove <NUM> and towards the bottom wall of the insertion groove <NUM> during an assembly of a panel with an adjacent panel. The flexible tongue <NUM> springs back towards its initial position when the panel has reached a joined position. A recess <NUM> is preferably arranged at each bendable protruding part.

The flexible tongue <NUM> may have a first displacement surface <NUM> and an opposite second displacement surface <NUM>, configured to be displaced along a third displacement surface <NUM> and a fourth displacement surface <NUM>, respectively, of the insertion groove <NUM>.

Another embodiment of the flexible tongue <NUM>, without the protruding bendable parts <NUM>, is shown in <FIG> shows a cross section of the flexible tongue <NUM> shown in <FIG>, which shows a top view. The alternative embodiment is bendable in the length direction of the flexible tongue <NUM> in order to accomplish a similar function as the embodiment shown in <FIG>.

Another embodiment of the flexible tongue <NUM> is shown in <FIG> in a top view. The tongue <NUM> comprises an inner part <NUM> and an outer part <NUM>. The inner part <NUM> and the outer part <NUM> are preferably made of two different materials, wherein the inner part <NUM> is more flexible than the outer part <NUM>. The inner part <NUM> is configured to be inserted into the insertion groove <NUM> and the outer part <NUM> is configured to extend into the tongue groove <NUM>.

<FIG> show cross section embodiments of the tongue <NUM> comprising an inner part <NUM> and a pivoting outer part <NUM>. The inner part <NUM> is configured to be inserted into the insertion groove <NUM> and the outer part <NUM> is configured to extend into the tongue groove <NUM> and pivot during assembly of a panel and an adjacent panel. The embodiments in <FIG> are preferably produced in one material, such as a polymer, by extruding. The embodiment in <FIG> is preferably produced by coextruding and comprises at least two different polymer materials. The embodiment comprises a hinge portion <NUM> which connects the inner part <NUM> and the outer part <NUM>. The material of the hinge portion <NUM> is preferably more flexible than the inner part <NUM> and the outer part <NUM>.

Claim 1:
A set of essentially identical subfloor panels (<NUM>, <NUM>', <NUM>") of a rectangular shape comprising a first edge (5a) and an opposite second edge (5b), a third edge (4a) and an opposite fourth edge (4b) which extend between the first edge (5a) and the opposite second edge (5b), and a joint configured to be glued, wherein the joint comprises a tongue (<NUM>) at a first edge (5a) of a first panel (<NUM>') and a tongue groove (<NUM>) at a second edge (5b) of a second panel (<NUM>"), wherein the tongue (<NUM>) and the tongue groove (<NUM>) are configured for positioning of the first panel (<NUM>') relative to the second panel (<NUM>") in a vertical direction, wherein a lower lip (<NUM>) of the tongue groove (<NUM>) extends beyond an upper lip (<NUM>) of the tongue groove (<NUM>),
wherein an outer edge of the lower lip (<NUM>) comprises a first impact surface (<NUM>), wherein the first impact surface is downward facing, and the first edge (5a) comprises a second impact surface (<NUM>), wherein the second impact surface is upward facing,
wherein the first impact surface (<NUM>) is configured to cooperate with the second impact surface (<NUM>) for partly absorbing a force (F) applied at an upper surface (<NUM>') of the first panel (<NUM>') and/or at an upper surface (<NUM>") of a second panel (<NUM>") when the first and the second panel are joined by the joint and assembled on joists (<NUM>, <NUM>'),
characterized in
that an element (<NUM>) protrudes from the lower lip (<NUM>) and an underside of the first edge (5a) comprises an element groove (<NUM>), wherein the element and the element groove are configured for positioning of the first panel (<NUM>') relative to the second panel (<NUM>") in a horizontal direction,
and that
the first edge (5a) of the first panel (<NUM>') is configured to be joined to the second edge (5b) of the second panel (<NUM>") by an angling motion (<NUM>) and the third edge (4a) of the first panel (<NUM>') is configured to be joined by the same angling motion to a fourth edge (4b) of a third panel (<NUM>),
wherein the joint for joining the third edge (4a) of the first panel (<NUM>') to a fourth edge (4b) of a third panel (<NUM>) comprises a flexible tongue (<NUM>) at the fourth edge, said flexible tongue being configured to cooperate with a tongue groove (<NUM>) at a third edge (4a) for positioning of the first panel (<NUM>') relative to the third panel (<NUM>) in a vertical direction.