초록 ▼

A machine for heat sealing articles between two continuous webs of plastic material comprises two parallel synchronously driven shafts, each of which has a pair of wheels on it which are brought into pressure relationship for heat sealing. One shaft is mounted for yielding perpendicularly to its rot

A machine for heat sealing articles between two continuous webs of plastic material comprises two parallel synchronously driven shafts, each of which has a pair of wheels on it which are brought into pressure relationship for heat sealing. One shaft is mounted for yielding perpendicularly to its rotational axis and carries a cam follower disc. The follower disc is raised intermittently and the seal wheels are thereby separated, to relieve pressure and omit sealing, with a cam that is on the other shaft and is engaged periodically for rotation by means of a clutch.

대표청구항 ▼

A device for producing pressure effected longitudinally extending seals and for periodically omitting seals between continuously longitudinally moving webs, comprising: first and second shaft means having their rotational axes in parallel, at least one of said shaft means being movable toward and aw

A device for producing pressure effected longitudinally extending seals and for periodically omitting seals between continuously longitudinally moving webs, comprising: first and second shaft means having their rotational axes in parallel, at least one of said shaft means being movable toward and away from the other, sealing wheel means on said respective shaft means for said webs to pass between them to effect a seal of predetermined length when the preipheries of said wheels are close to each other and to omit a seal when said peripheries are away from each other, means for biasing said first shaft means toward said second shaft means, a circular cam follower fixed coaxially on said first shaft means, a cam on said second shaft means for cooperating with said follower, said cam having a plurality of angularly spaced apart radially extending lobe means each of which has a circular peripheral surface having a radius from the axis of said second shaft means substantially equal to the radius of said follower means, said lobes defining angularly spaced apart recesses between them, clutch means operative to couple said second shaft means in driving relation with said cam to thereby rotate said lobe means successively into contact with said cam follower to cause said first shaft means to move away from said second shaft means and separate said wheel means to effect omission of a seal and operative to uncouple said cam means from said second shaft means when said cam means has rotated to the angle of a recess to thereby permit said first shaft means to move toward the second shaft means to effect a Seal, and means for operating said clutch means.