1. Field of the Invention
The present invention relates to an apparatus for connecting and locking structural panels, and more particularly to a locking structure of floor panels and a method of locking floor panels using the locking structure.
2. Background Description
Locking mechanism for floor panels are known, for example, DE 100 08 108. In such floor panels, a groove forms an upper lip and a lower lip over the entire length of at least one lateral border, and a tongue is formed on the opposite lateral border which corresponds to the groove. To lock panels that have been connected, the tongue is provided with at least one projection and the groove exhibits at least one indentation on the lip that faces the projection. The locking mechanism created by the corresponding profiling of the tongue and the groove forms a so-called “click profile”. Two panels are connected by inserting the tongue of one panel into the groove of the other panel, until the projection on the lower side of the tongue clicks into the recess formed in the lower lip of the groove.
In addition, panels are known from U.S. Pat. No. 4,426,820 or CH 562 377 A5 which are connected in the laying process by inserting the tongue of a new panel in an angular fashion into the groove of an already laid panel, and then lowering the panel to the floor. The tongue and groove of the two panels engage with each other so that panels are locked both in the transverse direction and perpendicular to the upper panel surface. These types of floor panels, as well as others, can be manufactured from diverse materials such as, for example, from a wood material, particularly MDF or HDF. The upper side is formed with a decorative layer applied to the core.
Panels that are combined to form a floor cover must be tight at the area of connection in the top surface to prevent moisture from penetrating the connection and to prevent the core material of the panels from swelling. For this reason the “clicking” mechanisms are designed in such a way that two panels inserted into each other are in a state of tension and the connected points are solidly pressed together at the surface. However, the core material of known panels is relatively sensitive, which is often not realized, particularly by those engaged in home repair. If care is not taken when laying the panels and if strong forces are exerted when a new panel is inserted or swung downwards there is the danger that the lower lip of the groove will buckle. This results in the required stress not being able to be applied to the floor panels during installation since the position of the interlocking mechanism has changed. Accordingly, it will become impossible to firmly join the panels. Also, if the lower lip buckles too much it is possible that the groove will be broken, a circumstance that cannot be identified from the outside.
It is further noted that the production of the click profiles is rather involved, since maintaining the given tolerances requires careful milling of the core material and demands continuous quality control. If, for example, tool wear results in the projection on the tongue being insufficiently high, the two panels will not lock together in solid fashion, and the danger will arise of the panels separating or of surface gaps forming at the connecting points. If the projection is too high it will not fit the lower lip of the panel provided with the groove. The danger may also arise of the lower lip buckling and being broken or the projection being damaged (ground down), making a solid connection of the panels impossible.