Apparatus for stretching plastic filaments

Claim 2

Apparatus for stretching a filament having a head on each end comprising first and second pairs of abutments engageable with said heads respectively, the abutments of each pair being disposed on opposite sides of the filament with a space therebetween less than the corresponding dimension of the head so that the pairs of abutments engage behind the heads respectively, means for moving the individual abutments of each pair away from each other a distance at least equal to the corresponding dimension of the heads so that the heads may be fed between the abutments, means for moving one pair of abutments away from the other pair along a path to stretch the filament, and means for feeding the filament in the direction of said path into engagement with said abutments, said pairs comprise abutments disposed on one side of the filament at first and second locations along said path, and means for conjointly actuating said moving means and feeding means including a bolster movable in the direction of said path, the bolster carrying the abutments on the other side of the filament and carrying means for moving the second pair of abutments away from the first pair after engagement with said heads.

Claim 3

Apparatus for stretching filaments extending away from a runner in opposite directions, each filament having an inner head at its inner end adjacent the runner and an outer head at its outer end, apparatus comprising a plate for supporting the runner and filaments, said plate having a first opening under the runner with first abutments on opposite sides thereof for engagement under said outer heads, a lower platen having a second opening under said first opening with second abutments on opposite sides thereof for engagement over said inner heads, a bolster being movable downwardly and having an upper platen, a plunger extending downwardly from the bolster in alignment with said openings for pushing the runner through the openings, third abutments on said upper platen for holding the outer heads over the first abutments, fourth abutments for holding the inner heads under said second abutments, the fourth abutments being slidable on the plunger between a retracted position in which the inner heads may pass the second abutments and an advanced position in which the inner heads are held under the second abutments, and means for holding the fourth abutments in said retracted position until the inner heads have passed the second abutments and for then advancing the fourth abutments relatively to the plunger into opposition to the second abutments and for then causing the second and fourth abutments to advance together to stretch the filaments.

Claim 4

Apparatus for stretching filaments extending away from a runner in opposite directions, each filament having an inner head at its inner end adjacent the runner and an outer head at its outer end, apparatus comprising a plate for supporting the runner and filaments, said plate having a first opening under the runner with first abutments on opposite sides thereof for engagement under said outer heads, a lower platen having a second opening under said first opening with second abutments on opposite sides thereof for engagement over said inner heads, a bolster being movable downwardly and having an upper platen, a plunger extending downwardly from the bolster in alignment with said openings for pushing the runner through the openings, third abutments on said upper platen for holding the outer heads over the first abutments, fourth abutments for holding the inner heads under said second abutments, the fourth abutments being slidable on the plunger between a retracted position in which the inner heads may pass the second abutments and an advanced position in which the inner heads are held under the second abutments, and means for holding the fourth abutments in said retracted position until the inner heads have passed the second abutments and for then advancing the fourth abutments relatively to the plunger into opposition to the second abutments and for then causing the second and fourth abutments to advance together to stretch the filaments.

Claim 5

Apparatus according to claim 2 further characterized by a depending stem on said bolster and wherein said upper platen is slidably mounted on said stem, the third abutments being disposed on said upper platen so that their downward movement is stopped by engagement with said outer heads.

Claim 6

Apparatus according to claim 3 wherein said stem has a shoulder to limit the downward movement of the upper platen.

Claim 7

Apparatus according to claim 3 further characterized by means for yieldingly supporting said lower platen and means on said stem for pushing the lower platen downwardly against the yielding means after the fourth abutments have moved into opposition to the second abutments.

Claim 8

Apparatus according to claim 2 further characterized by means for severing and ejecting the runner after the fourth abutments have reached the second abutments.

Claim 9

Apparatus according to claim 6 further characterized by a hopper below said openings to catch the stretched filaments, and means to move the hopper from beneath the openings while the runner is being ejected.