Machine for closuring containers

Claim 1

Apparatus for heat-sealing thin flexible closure material to the periphery of one end of the container, comprising a base, means on the base for guiding an indexable web of the closure material and leaving free of access on one surface thereof an area greater than the area of the said one end of the container, means on the base for locating a container with its said one end facing towards the said area of the material, means operative to move the locating means and the web guiding means towards each other so as to bring the said one end of the container on the locating means into contact with the said area of the closure material, the web guiding means including first and second clamping plates which have aligned apertures greater in area than the area of the said one end of the container, the said plates being mounted on the base to be movable relatively towards each other and to define a gap between them for receiving and guiding the said web, and means for arresting movement of one said plate as the container locating means and the web guiding means move towards each other, whereby the other plate clamps the web to the said one plate along a line outside the said area as the container locating means and the web guiding means move towards each other, a heatable cylindrically shaped sealing tool mounted on the base on the opposite side of the web guiding means to the container locating means with its cylindrical axis substantially perpendicular to and centrally of the said apertures, means for causing relative movement, in a direction perpendicular to the direction of web movement, between the web guiding means and the locating means on the one hand and the tool on the other hand so as to bring the tool into contact with the opposite surface of the closure material with a controlled pressure, after the closure material is supported by the end of the container, the tool having an end sized to match the periphery of the said end of the container whereby the tool applies heat to seal the closure material to the periphery of the said end of the container, a tubular shaped knife blade mounted on the said base around the outside of the said tool for limited reciprocable movement relative thereto to contact the closure material through the said apertures and around the outside of the periphery of the container as the said relative movement continues in the said perpendicular direction, whereby the knife blade is operative to sever the closure material on the end of the container from the remainder of the web, and tubular wipe-down means mounted between and to space apart the said tool and the knife blade and fixed to the latter to move therewith, the wipe-down means having an end surface which forms down around the container the annular region of the said closure material between the outer periphery of the Container and the knife blade.