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US 2003/0154588 A1Published application
Fastening of sheet material
AssigneeHenrob Limited
InventorsStuart Edmund Blacket, Nicholas Richard Clew
Life of this patent
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AssigneeHenrob Limited
InventorsStuart Edmund Blacket, Nicholas Richard Clew
Estimating the term…
A fastener such as a self piercing rivet is inserted into sheet material without full penetration such that the deformed end of the rivet remains encapsulated by an upset annulus of the sheet material. The sheet material is disposed between a nose and a die of fastening apparatus. The rivet is inserted into the sheet material by means of a plunger that is reciprocal relative to the nose. Prior to rivet insertion no significant clamping force is applied to the sheet material and material immediately around the rivet insertion location is allowed to flow towards the rivet as to rivet is inserted. Thereafter during a second stage (being after said first stage) of rivet insertion a clamping force of sufficient magnitude is applied between the nose and the die in the region around the rivet insertion location so as substantially to prevent flow of displaced sheet material away from the rivet. The invention may also be applied to panel clinching. The resulting joints are of improved mechanical strength and fatigue life. Certain components of the apparatus of the present invention have an improved life expectancy.
A method for inserting a fastener into sheet material comprising inserting the fastener into at least one sheet without full penetration such that a deformed end of the fastener remains encapsulated by an upset annulus of the sheet material, the sheet material being disposed between a nose and a die of fastening apparatus and the fastener being inserted into the sheet material by means of a plunger that is reciprocal relative to the nose, characterised in that, during a first stage of fastener insertion the sheet material around the fastener insertion location is displaced towards the fastener by virtue of its insertion, and thereafter during a second stage (being after said first stage) of fastener insertion a clamping force of sufficient magnitude is applied between the nose and the die in the region around fastener insertion location so as substantially to prevent flow of displaced sheet material away from the fastener.
Apparatus for inserting a fastener into sheet material without full penetration such that a deformed end of the fastener remains encapsulated by an upset annulus of the sheet material, said apparatus comprising a nose in which is disposed a reciprocal plunger, means for feeding fasteners successively to the nose for insertion by the plunger into the sheet material, a die aligned with the plunger for deforming the fastener being inserted, the sheet material being disposed between the nose and die during the fastening operation, characterised in that there is provided means for applying a clamping force at a predetermined point during insertion of the fastener, said means for applying the clamping force allowing the sheet material around the fastener insertion location to be displaced by the fastener towards the fastener during a first stage of fastener insertion, and thereafter during a second stage (being after said first stage) of fastener insertion applies a clamping force of sufficient magnitude between the nose and the die in the region around fastener insertion location so as substantially to prevent flow of displaced sheet material away from the fastener.
A panel clinching method wherein two or more sheets of material are deformed into locking engagement, the sheet material being disposed between a nose and a die of fastening apparatus, the sheet material being deformed by means of a plunger that is reciprocal relative to the nose, characterised in that, during a first stage of deformation, the sheet material around the deformation region is displaced towards the towards the plunger by virtue of its insertion into the material, and thereafter during a second stage (being after said first stages) of deformation a clamping force of sufficient magnitude is applied between the nose and the die in the region around the deformation so as substantially to prevent flow of displaced sheet material away from the plunger.
Dependencies are inferred from the claim text.