Apparatus for the fastening together of sheet materials

Apparatus for the fastening together of two superimposed sheets of material using an integral fastener comprising:

• an apparatus body,
• a punch member mounted by the body for movement along a longitudinal axis toward and away from a sheet receiving station,
• an extrusion die member of segmented form surrounding the said longitudinal axis for cooperation with the punch member upon engagement of the latter with sheet material at the sheet receiving station to form the engaged portion of the sheet material to a cylindrical formation,
• a curl die member mounted by the body for movement along the said longitudinal axis toward and away from the sheet receiving station and engageable with the said cylindrical formation to curl the sheet portions back toward the adjacent sheet and thereby form a fastening between them,
• movement of the curl die member to curl the cylindrical formation being accompanied by movement of the extrusion die member to an inoperative position, and
• means for moving the punch member into engagement with the sheet material and for moving the curl die member into engagement with the cylindrical formation subsequent to the said engagement of the punch member,
• wherein the extrusion die member is operative in a bore in the apparatus body, the die member segments and the bore having cooperating radially-acting cam faces to move the segments radially inwards to an operative position as the punch member moves along the longitudinal axis toward the sheet receiving station.

Apparatus for the fastening together of two superimposed sheets of material using an integral fastener comprising:

• an apparatus body,
• a punch member mounted by the body for movement along a longitudinal axis toward and away from a sheet receiving station,
• an extrusion die member surrounding the said longitudinal axis for cooperation with the punch member to lance registering portions from the superimposed sheets upon engagement of the latter with sheet material at the sheet receiving station to form the engaged lanced portion of the sheet material to a depressed formation, the extrusion die member being engageable thereafter with the sheet material adjacent the said lanced depressed portion to extrude the said adjacent portions over the lanced depressed portions and thereby form a fastening between them, and
• means for moving the punched member into engagement with the sheet material and for moving the extrusion die member into engagement with the sheet material subsequent to the said engagement of the punch member,
• wherein the said moving means move the punch and extrusion die members simultaneously, the moving means moving the extrusion die member away from the sheet receiving station as it moves the punch member toward the station, and vice versa, and wherein the said moving means moves the punch member toward and away from the sheet receiving station at a faster rate and with a greater excursion than it moves the extrusion die member toward and away from the sheet receiving station.