A button back which makes it possible to form the front surface of a button to be a circular shape; a shell cap hard to be rotated; and an umbrella part hard to be deformed. The button back is made of metal, including a cylindrical part and an umbrella part extending radially outward from one axial end of the cylindrical part. The umbrella part includes a first bending part which extends radially outward from the one axial end of the cylindrical part and then bends on the opposite side of the cylindrical part. An outer periphery, including a radially outer end, of the first bending part has a polygonal shape including at least three corners and sides which extend between two circumferentially adjacent corners. The umbrella part includes flat plates extending radially outward from the radially outer end, corresponding to the sides, of the first bending part.

A button back which makes it possible to form the front surface of a button to be a circular shape; a shell cap hard to be rotated; and an umbrella part hard to be deformed. The button back is made of metal, including a cylindrical part and an umbrella part extending radially outward from one axial end of the cylindrical part. The umbrella part includes a first bending part which extends radially outward from the one axial end of the cylindrical part and then bends on the opposite side of the cylindrical part. An outer periphery, including a radially outer end, of the first bending part has a polygonal shape including at least three corners and sides which extend between two circumferentially adjacent corners. The umbrella part includes flat plates extending radially outward from the radially outer end, corresponding to the sides, of the first bending part.

A rivet is applied from a rear surface of a fabric for mounting a burr on a front surface of the fabric. The rivet comprises a disk-shaped base, and a shank projecting from and concentrically with the base. The base includes an annular recess around a proximal end of the shank, which is depressed in a direction opposite to the shank-projecting direction, and a flange radially outward from the recess. The flange includes a plurality of bumps which are raised from an upper surface in the shank-projecting direction. The bumps may be provided on the upper surface of the flange at equal circumferential intervals, and a top of each of the bumps may be a curved face. The recess may have an inclined outer surface adjacent to the flange. Each of the bumps may have an inclined inner surface extending continuously from the inclined outer surface of the recess.

A rivet is applied from a rear surface of a fabric for mounting a burr on a front surface of the fabric. The rivet comprises a disk-shaped base, and a shank projecting from and concentrically with the base. The base includes an annular recess around a proximal end of the shank, which is depressed in a direction opposite to the shank-projecting direction, and a flange radially outward from the recess. The flange includes a plurality of bumps which are raised from an upper surface in the shank-projecting direction. The bumps may be provided on the upper surface of the flange at equal circumferential intervals, and a top of each of the bumps may be a curved face. The recess may have an inclined outer surface adjacent to the flange. Each of the bumps may have an inclined inner surface extending continuously from the inclined outer surface of the recess.

A connection assembly includes a first attachment strap, a first mating assembly, a second attachment strap, a second mating assembly, and a tool key, which connection assembly is used to releasable couple a first article to a second article. The first attachment strap is inserted through a loop in the first article then folded around the loop. The first mating assembly is positioned on opposing ends of the first attachment strap. The second attachment strap is inserted through a loop in the second article and then folded around the loop. The second mating assembly is positioned on opposing ends of the second attachment strap. The tool key is used to rotate a rotatable portion of each of the first mating assembly and the second mating assembly to secure them in place on their respective attachment straps. The first and second mating assemblies are then releasably coupled together.

A connection assembly includes a first attachment strap, a first mating assembly, a second attachment strap, a second mating assembly, and a tool key, which connection assembly is used to releasable couple a first article to a second article. The first attachment strap is inserted through a loop in the first article then folded around the loop. The first mating assembly is positioned on opposing ends of the first attachment strap. The second attachment strap is inserted through a loop in the second article and then folded around the loop. The second mating assembly is positioned on opposing ends of the second attachment strap. The tool key is used to rotate a rotatable portion of each of the first mating assembly and the second mating assembly to secure them in place on their respective attachment straps. The first and second mating assemblies are then releasably coupled together.

A female fastener that holds a resin ring spring accommodated in an accommodation housing of the female fastener, wherein the resin ring spring accommodated in the accommodation housing locks a male fastener inserted therein. The resin ring spring includes a plurality of outwardly projecting convex portions provided at a predetermined interval, in such a manner that, when the resin ring spring is in a natural state accommodated in the accommodation housing, a diametrical gap between an inner circumferential wall of the accommodation housing and an outer circumference of the ring spring increases and decreases alternately. A difference between an outer diameter of the resin ring spring and an inner diameter of the accommodation housing is 0.2 mm or less.

A button assembly configured for fast button attachment to a cloth. The assembly includes button attached to a spacer attached to a pole attached to a terminal element and a separate cone. This configuration is retained by a ring with multiplicity of resilient gates. The terminal element has holding cavity at its bottom end. The cone has a pointed end pointing downwards and a wide upper side with an attached holding pole which facilitates temporary attachment to the terminal element. Piercing the cloth downwards, by the cone followed by the terminal element and the pole bends downwards the resilient gates which are situated beneath the cloth. When the terminal element is inserted below the bent ends of the resilient gates, the gates are released, unbend, and trap the terminal element in the ring. This attaches the button on top of the cloth and the cone is detached and discarded.

A button assembly configured for fast button attachment to a cloth. The assembly includes button attached to a spacer attached to a pole attached to a terminal element and a separate cone. This configuration is retained by a ring with multiplicity of resilient gates. The terminal element has holding cavity at its bottom end. The cone has a pointed end pointing downwards and a wide upper side with an attached holding pole which facilitates temporary attachment to the terminal element. Piercing the cloth downwards, by the cone followed by the terminal element and the pole bends downwards the resilient gates which are situated beneath the cloth. When the terminal element is inserted below the bent ends of the resilient gates, the gates are released, unbend, and trap the terminal element in the ring. This attaches the button on top of the cloth and the cone is detached and discarded.