Method of making a riveted jointure

Claim 1

A method of joining an apertured tab of sheet material to a container wall wherein the container wall has a line of weakness forming a tear portion and a hollow rivet with a peripheral wall and a transverse end wall is attached to the container wall and projects through the aperture of the tab, said method comprising: providing a punch having a working surface with the working surface having a first region and a bead forming region with the bead forming region at least substantially circumscribing the first region and tapering axially of the first region toward the container wall as it extends radially outwardly; supporting the rivet against inward collapse by inserting a support member into the hollow rivet with the support member being spaced from the transverse end wall; relatively advancing said punch and the rivet toward each other to impact the first region of the working surface against the transverse end wall to axially collapse said hollow rivet with consequent radial outward flow of material to form a bead integrally joining the peripheral wall and the transverse end wall with the relative advance of the punch and rivet causing said bead forming region to force the bead against the region of the tab immediately surrounding the aperture; said step of relatively advancing being carried out without substantially deforming said support member; relatively moving the support member and the rivet to withdraw the support member from the rivet without destroying the rivet, the withdrawal of the support member occurring after the formation of the bead.

Claim 2

A method of joining an apertured tab of sheet material to a container wall wherein the container wall has a line of weakness forming a tear portion and a hollow rivet with a peripheral wall and a transverse end wall is attached to the container wall and projects through the aperture of the tab, said method comprising: providing a punch having a working surface with the working surface having a first region and a bead forming region with the bead forming region at least substantially circumscribing the first region and tapering axially of the first region toward the container wall as it extends radially outwardly; supporting the rivet against inward collapse by inserting a support member into the hollow rivet with the support member being spaced from the transverse end wall; relatively advancing said punch and the rivet toward each other to impact the first region of the working surface against the transverse end wall to axially collapse said hollow rivet with consequent radial outward flow of material to form a bead integrally joining the peripheral wall and the transverse end wall with the relative advance of the punch and rivet causing said bead forming region to force the bead against the region of the tab immediately surrounding the aperture; said step of relatively advancing being carried out without substantially deforming said support member; relatively moving the support member and the rivet to withdraw the support member from the rivet without destroying the rivet, the withdrawal of the support member occurring after the formation of the bead.

Claim 8

A method of joining an apertured tab of sheet material to a container wall wherein the container wall has a line of weakness forming a tear portion and a hollow rivet with a peripheral wall and a transverse end wall is attached to the container wall and projects through the aperture of the tab, said method comprising: providing a punch having a working surface defining a cavity having an inner end and sloping sides which slope radially outwardly as they extend away from the inner end, said working surface having a first region defining at least a portion of the inner end of the cavity and a bead forming region defining at least a portion of the sides of said cavity, said bead forming region at least substantially circumscribing the first region; relatively positioning the punch and the container wall so that the cavity opens toward the transverse end wall; supporting the rivet against radial inward collapse by inserting a support member into the hollow rivet with the support member being spaced from the transverse end wall; relatively advancing said punch and the rivet toward each other to impact the first region of the working surface against the transverse end wall to initiate axial collapse of said hollow rivet with consequent radial outward movement of material to at least initiate formation of a bead with the relative advance of the punch and rivet causing said bead forming region to engage some of the material of the bead and shaping the surface of the material so engaged so that said surface tapers axially away from the first region as it extends radially outwardly whereby said surface has a configuration which mates with the sides of said cavity; and relatively moving the support member and the rivet to withdraw the support member from the rivet without destroying the rivet, the withdrawal of the support member occurring after the formation of the bead.

Claim 9

A method of joining an apertured tab of sheet material to a container wall wherein the container wall has a line of weakness forming a tear portion and a hollow rivet with a peripheral wall and a transverse end wall is attached to the container wall and projects through the aperture of the tab, said method comprising: providing a punch having a working surface defining a cavity having an inner end and sloping sides which slope radially outwardly as they extend away from the inner end, said working surface having a first region defining at least a portion of the inner end of the cavity and a bead forming region defining at least a portion of the sides of said cavity, said bead forming region at least substantially circumscribing the first region; relatively positioning the punch and the container wall so that the cavity opens toward the transverse end wall; supporting the rivet against radial inward collapse by inserting a support member into the hollow rivet with the support member being spaced from the transverse end wall; relatively advancing said punch and the rivet toward each other to impact the first region of the working surface against the transverse end wall to initiate axial collapse of said hollow rivet with consequent radial outward movement of material to at least initiate formation of a bead with the relative advance of the punch and rivet causing said bead forming region to engage some of the material of the bead and shaping the surface of the material so engaged so that said surface tapers axially away from the first region as it extends radially outwardly whereby said surface has a configuration which mates with the sides of said cavity; and relatively moving the support member and the rivet to withdraw the support member from the rivet without destroying the rivet, the withdrawal of the support member occurring after the formation of the bead.

Claim 10

A method of joining an apertured tab of sheet material to a container wall wherein the container wall has a sealant coating on the inner surface thereof and a line of weakness forming a tear portion and wherein a hollow rivet with a peripheral wall and a transverse end wall is attached to the container wall and projects through the aperture of the tab, said method comprising: providing a punch having a working surface with the working surface having a first region and a bead forming region with the bead forming region at least substantially circumscribing the first region and tapering radially outwardly whereby said regions define a cavity which opens toward the rivet; supporting the container wall; supporting the rivet against radial inward collapse by inserting a support member into the hollow rivet with the support member being spaced from the transverse end wall; relatively advancing said punch and the rivet to impact the first region of the working surface against the transverse end wall to initiate axial collapse of said hollow rivet with consequent radial outward flow of material to initiate formation of a bead with the relative advance of the punch and rivet causing said bead forming region to engage the bead and force the portion so engaged axially of the outer surface of the transverse end wall whereby the bead is forced against the region of the tab immediately surrounding the aperture; said step of relatively advancing being carried out without extruding the material of the transverse end wall; and relatively moving the support member and the rivet to withdraw the support member from the rivet without destroying the rivet, the withdrawal of the support member occurring after the formation of the bead.

Claim 11

A method of joining an apertured tab of sheet material to a container wall wherein the container wall has a sealant coating on the inner surface thereof and a line of weakness forming a tear portion and wherein a hollow rivet with a peripheral wall and a transverse end wall is attached to the container wall and projects through the aperture of the tab, said method comprising: providing a punch having a working surface with the working surface having a first region and a bead forming region with the bead forming region at least substantially circumscribing the first region and tapering radially outwardly whereby said regions define a cavity which opens toward the rivet; supporting the container wall; supporting the rivet against radial inward collapse by inserting a support member into the hollow rivet with the support member being spaced from the transverse end wall; relatively advancing said punch and the rivet to impact the first region of the working surface against the transverse end wall to initiate axial collapse of said hollow rivet with consequent radial outward flow of material to initiate formation of a bead with the relative advance of the punch and rivet causing said bead forming region to engage the bead and force the portion so engaged axially of the outer surface of the transverse end wall whereby the bead is forced against the region of the tab immediately surrounding the aperture; said step of relatively advancing being carried out without extruding the material of the transverse end wall; and relatively moving the support member and the rivet to withdraw the support member from the rivet without destroying the rivet, the withdrawal of the support member occurring after the formation of the bead.