joint plane vertical joining of the first and second joint edge portions wherein the tongue the tongue groove the locking element and the locking groove have a configuration that allows insertion of the locking element into the locking groove by inward angling of the second floorboard towards the first floorboard while maintaining contact between the joint edge portions and wherein the tongue the tongue grove the locking element and the locking groove have a configuration that allows insertion of the locking element into the locking groove by a substantially vertical snap action application_number US 62797107 A description prior to the description of preferred embodiments with reference to fig5 a detailed explanation will first be given of the most important parts in a strip lock system the invention can be applied in joint systems with a worked strip which is made in one piece with the core of the board or with a strip which is integrated with the core of the board but which has been made of a separate material for instance aluminium since the worked embodiment where strip and core are made of the same material constitutes the greatest problem owing to higher friction and poorer flexibility the following description will focus on this field of application the cross sections shown in fig5 are hypothetical not published cross sections but they are fairly similar.