Abstract: The invention relates to a hollow board material comprising a first sheet and a second sheet. A first and a second lath are arranged in parallel between the first sheet and the second sheet along opposite edges of the hollow board material. The first lath and the first sheet are attached to each other by means of a first metal gripping lamina which at least partly covers the first lath. The second lath and the first sheet are attached to each other by means of a second metal gripping lamina which at least partly covers the first lath. Optionally, the first lath and the second sheet are attached to each other by means of a third metal gripping lamina and optionally the second lath and the second sheet are attached to each other by means of a fourth metal gripping lamina. The metal gripping laminas have a first face and a second face which are opposed to each other. Each face comprises a plurality of sharp projections extending substantially perpendicular therefrom and into the laths or the sheets respectively.

Abstract: A method for joining two objects by anchoring an insert portion provided on a first object in an opening provided on a second object. The anchorage is achieved by liquefaction of a thermoplastic material and interpenetration of the liquefied material and a penetrable material, the two materials being arranged on opposite surfaces of the insert portion and the wall of the opening. During the step of inserting the insert portion in the opening and/or during anchorage a clamping force is applied to opposing surfaces of the second object to prevent the second object from cracking or bulging.

Abstract: A device for joining material by anchoring an insert comprising a first material in a structure comprising a second material is provided. The first material is solid and comprises thermoplastic properties and the second material is solid and is penetrable by the first material when in a liquefied state. The device comprises a vibration device being configured to transmit vibrations to said insert to cause at least partial liquefaction thereof and being arranged to move, relative to said structure, along an insertion direction (ID) to insert said insert at least partly into said structure, a contact sensor being connected to the vibration device and being adapted to move together with the vibration device along the insertion direction (ID), the contact sensor having a sensor body being adapted to detect contact with said structure.

Abstract: A method for joining two objects by anchoring an insert portion provided on a first object in an opening provided on a second object. The anchorage is achieved by liquefaction of a thermoplastic material and interpenetration of the liquefied material and a penetrable material, the two materials being arranged on opposite surfaces of the insert portion and the wall of the opening. During the step of inserting the insert portion in the opening and/or during anchorage a clamping force is applied to opposing surfaces of the second object to prevent the second object from cracking or bulging.

Abstract: A device for joining material by anchoring an insert comprising a first material in a structure comprising a second material is provided. The first material is solid and comprises thermoplastic properties and the second material is solid and is penetrable by the first material when in a liquefied state. The device comprises a vibration device being configured to transmit vibrations to said insert to cause at least partial liquefaction thereof and being arranged to move, relative to said structure, along an insertion direction (ID) to insert said insert at least partly into said structure, a contact sensor being connected to the vibration device and being adapted to move together with the vibration device along the insertion direction (ID), the contact sensor having a sensor body being adapted to detect contact with said structure.

Abstract: A method for joining two objects by anchoring an insert portion provided on a first object in an opening provided on a second object. The anchorage is achieved by liquefaction of a thermoplastic material and interpenetration of the liquefied material and a penetrable material, the two materials being arranged on opposite surfaces of the insert portion and the wall of the opening. During the step of inserting the insert portion in the opening and/or during anchorage a clamping force is applied to opposing surfaces of the second object to prevent the second object from cracking or bulging.

Abstract: A joining element has an anchoring portion for in-depth anchoring in the object and a head portion arranged proximally of the anchoring portion with respect to an insertion axis. The head portion has a lateral outer surface that has a structure that is well-defined, especially within tight tolerances. The joining element is positioned relative to an object of a non-liquefiable material such that the anchoring portion reaches into an opening of the object or is placed adjacent a mouth thereof. Then, the joining element is pressed towards a distal direction, to press the anchoring portion into the opening, while mechanical vibration energy is coupled into the joining element by a tool, in an amount and for a time sufficient for liquefaction of a portion of the thermoplastic material to cause interpenetration of the thermoplastic material into structures of the object.

Abstract: A first object is anchored in a second object. The first object has a material with thermoplastic properties, and the second material has a material that is solid and is penetrable by the first material when in a liquefied state. The second object has an insertion face with an opening having a mouth in the insertion face, and the first object has an insert portion that for anchoring is placed in the opening or about the mouth thereof. For anchoring, energy suitable for liquefaction of the first material impinges in an amount and for a time sufficient for at least partial liquefaction of the first material and interpenetration of the first and second materials. The second object, around the opening, has an anisotropic strength with respect to forces perpendicular to the opening axis.

Abstract: A first object is anchored in a second object. The first object has a material with thermoplastic properties, and the second material has a material that is solid and is penetrable by the first material when in a liquefied state. The second object has an insertion face with an opening having a mouth in the insertion face, and the first object has an insert portion that for anchoring is placed in the opening or about the mouth thereof. For anchoring, energy suitable for liquefaction of the first material impinges in an amount and for a time sufficient for at least partial liquefaction of the first material and interpenetration of the first and second materials. The second object, around the opening, has an anisotropic strength with respect to forces perpendicular to the opening axis.

Abstract: A joining element has an anchoring portion for in-depth anchoring in the object and a head portion arranged proximally of the anchoring portion with respect to an insertion axis. The head portion has a lateral outer surface that has a structure that is well-defined, especially within tight tolerances. The joining element is positioned relative to an object of a non-liquefiable material such that the anchoring portion reaches into an opening of the object or is placed adjacent a mouth thereof. Then, the joining element is pressed towards a distal direction, to press the anchoring portion into the opening, while mechanical vibration energy is coupled into the joining element by a tool, in an amount and for a time sufficient for liquefaction of a portion of the thermoplastic material to cause interpenetration of the thermoplastic material into structures of the object.

Abstract: A method for joining two objects by anchoring an insert portion provided on a first object in an opening provided on a second object. The anchorage is achieved by liquefaction of a thermoplastic material and interpenetration of the liquefied material and a penetrable material, the two materials being arranged on opposite surfaces of the insert portion and the wall of the opening. During the step of inserting the insert portion in the opening and/or during anchorage a clamping force is applied to opposing surfaces of the second object to prevent the second object from cracking or bulging.