US4601689A — Method and apparatus for folding polymeric sheet …

Claim 1

Independent Claim 168 words

A method for folding polymeric sheet material, in steps comprising: (a) Positioning the sheet material in a firmly held position; (b) Positioning a mandrel plate such that an edge of said mandrel plate is aligned with a preselected fold line on the interior side of the sheet; (c) Positioning an exterior heater element against the exterior portion of the sheet along said fold line; (d) Positioning an interior heater element against the interior portion of the sheet along said fold line; (e) Applying a preselected amount of heat by conduction to the fold line area of the sheet through said exterior heater element; (f) Applying a preselected amount of heat by conduction to the fold line area of the sheet through said interior heater element; (g) Retracting said upper heater element from the vicinity of the sheet; (h) Folding the sheet along said fold line about said mandrel plate; and (i) Annealing the fold area by applying a further preselected amount of heat through said exterior heater element.

Claim 2

Independent Claim 168 words

A method for folding polymeric sheet material, in steps comprising: (a) Positioning the sheet material in a firmly held position; (b) Positioning a mandrel plate such that an edge of said mandrel plate is aligned with a preselected fold line on the interior side of the sheet; (c) Positioning an exterior heater element against the exterior portion of the sheet along said fold line; (d) Positioning an interior heater element against the interior portion of the sheet along said fold line; (e) Applying a preselected amount of heat by conduction to the fold line area of the sheet through said exterior heater element; (f) Applying a preselected amount of heat by conduction to the fold line area of the sheet through said interior heater element; (g) Retracting said upper heater element from the vicinity of the sheet; (h) Folding the sheet along said fold line about said mandrel plate; and (i) Annealing the fold area by applying a further preselected amount of heat through said exterior heater element.

Claim 3

Dependent Claim 13 words

The method of claim 1 wherein steps (c) and (d) are performed simultaneously.

Claim 4

Dependent Claim 30 words

The method of claim 1 wherein, subsequent to step (e), a further preselected amount of heat, greater than the amount of step (e), is applied through said exterior heater element.

Claim 5

Dependent Claim 39 words

The method of claim 1 wherein the folding of step (h) is accomplished by applying a rotary folding head apparatus to the exterior of the sheet and forcing the sheet to fold about the edge of said mandrel plate.

Claim 6

Dependent Claim 31 words

The method of claim 4 wherein said folding head continues to force the sheet into the folded position about the mandrel plate until the annealing process of step (i) is completed.

Claim 7

Dependent Claim 44 words

The method of claim 1 wherein, prior to step (c), a preselected portion of adhesive is applied to the portion of the sheet which is to be folded, such that said adhesive will cause adherence of the folded sheet to another portion of itself.

Claim 8

Dependent Claim 28 words

The method of claim 1 and further including: (j) Removing said mandrel plate from the vicinity of said fold, and transporting the folded sheet from the fold area.

Claim 9

Dependent Claim 38 words

The method of claim 1 wherein the sheet material includes a flap to be folded along said fold line such that the interior side of a portion of said flap abuts against an additional portion of said sheet.

Claim 10

Dependent Claim 26 words

The method of claim 8 wherein, subsequent to step (h), said flap is welded to said additional portion of said sheet by a heat stake mechanism.

Claim 11

Dependent Claim 47 words

The method of claim 1 further including, subsequent to step (f), a step of delivering said exterior heating element to an extended position against the polymeric material for a short distance so as to urge the material to deform slightly about the edge of said mandrel plate.

Claim 12

Dependent Claim 47 words

The method of claim 5 further including, subsequent to step (f) a step of delivering said exterior heating element to an extended position against the polymeric material for a short distance, so as to urge the material to deform slightly about the edge of said mandrel plate.

Claim 13

Dependent Claim 30 words

The method of claim 11 wherein said exterior heating element is maintained in said extended position throughout said folding and annealing steps and then is reset to its original position.

Claim 14

Dependent Claim 172 words

Flexible disk jackets formed from precut sheets of polymeric material by process including steps comprising; (a) positioning a sheet of material in a firmly held position; (b) Positioning a mandrel plate such that an edge of said mandrel plate is aligned with a preselected fold line on the interior side of the sheet; (c) Positioning an exterior heater element against the interior portion of the sheet along said fold line; (d) Positioning an interior heater element against the interior portion of the sheet along said fold line; (e) Applying a preselected amount of heat to the fold line area of the sheet through said exterior heater element; (f) Applying a preselected amount of heat by conduction to the fold line area of the sheet through said interior heater element; (g) Retracting said upper heater element from the vicinity of the sheet; (h) Folding the sheet along said fold line about said mandrel plate; and (i) Annealing the fold area by applying a further preselected amount of heat through said exterior heater element.

Claim 15

Dependent Claim 172 words

Flexible disk jackets formed from precut sheets of polymeric material by process including steps comprising; (a) positioning a sheet of material in a firmly held position; (b) Positioning a mandrel plate such that an edge of said mandrel plate is aligned with a preselected fold line on the interior side of the sheet; (c) Positioning an exterior heater element against the interior portion of the sheet along said fold line; (d) Positioning an interior heater element against the interior portion of the sheet along said fold line; (e) Applying a preselected amount of heat to the fold line area of the sheet through said exterior heater element; (f) Applying a preselected amount of heat by conduction to the fold line area of the sheet through said interior heater element; (g) Retracting said upper heater element from the vicinity of the sheet; (h) Folding the sheet along said fold line about said mandrel plate; and (i) Annealing the fold area by applying a further preselected amount of heat through said exterior heater element.

Claim 16

Dependent Claim 33 words

The jackets of claim 13 wherein said process further includes, subsequent to step (e), application of further preselected amount of heat, greater than the amount of step (e), through said exterior heater element.

Claim 17

Dependent Claim 39 words

The jackets of claim 13 wherein the folding of step (h) is accomplished by applying a rotary folding head apparatus to the exterior of the sheet and forcing the sheet to fold about the edge of said mandrel plate.

Claim 18

Dependent Claim 31 words

The jackets of claim 15 wherein said folding head continues to force the sheet into the folded position about the mandrel plate until the annealing process of step (i) is completed.

Claim 19

Dependent Claim 44 words

The jackets of claim 13 wherein, prior to step (c), a preselected portion of adhesive is applied to the portion of the sheet which is to be folded, such that said adhesive will cause adherence of the folded sheet to another portion of itself.

Claim 20

Dependent Claim 43 words

The jackets of claim 13 wherein the sheet material includes a flap to be folded along said fold line such that the interior side of a portion of said flap abuts against an additional portion of said sheet when the fold is completed.

Claim 21

Dependent Claim 26 words

The jackets of claim 18 wherein, subsequent to step (h), said flap is welded to said additional portion of said sheet by a heat stake mechanism.

Claim 22

Dependent Claim 48 words

The jackets of claim 13 and further including, subsequent to step (f), a step of delivering said exterior heating element to an extended position against the polymeric material for a short distance so as to urge the material to deform slightly about the edge of said mandrel plate.

Claim 23

Dependent Claim 50 words

The jackets of claim 16 and further including, subsequent to step (f), a step of delivering said exterior heater element to an extended position against the polymeric material so as to force the polymeric material to deform about the edge of said mandrel plate and to be partially folded thereabout.

Claim 24

Dependent Claim 29 words

The jackets of claim 21 wherein said exterior heating element is maintained in said extended position throughout said folding and annealing steps and then reset to its original position.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1989-07-21	1990-01-20	1990-07-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1993-07-21	1994-01-20	1994-07-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1997-07-21	1998-01-20	1998-07-22	$7700.00	Window Closed / Lapsed

Method and apparatus for folding polymeric sheet material and flexible disk jackets made thereby

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