US3849864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making bellows
Assignee: Individual
•
Filing: 1973-05-22
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Granted: 1974-11-26
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Expires: 1993-05-22
Abstract
Abstract An axially contractable and expandable resilient bellows and a simple method of making the same from flexible heat reactive thermoplastic sheet material. The bellows may include a separable seam formed of interlocking tongue and groove plastic tapes permitting the installation and removal of the bellows without need for access to the opposite ends of the structure embraced. The processing of the bellows includes heating the material while supported on a coil or the like to shrink the same and form a deep spiralling convolution therealong. Any of a wide variety of shapes can be formed by selecting an appropriate form.
Inventors
- 👤 W Plummer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:36
CPC Classifications
B; B29; B29C; B29C53/00; B29C53/22; B29C53/30; B29C61/00; B29C61/02; B29C61/025; B29L; B29L2023/00; B29L2023/18; B29L2031/00; B29L2031/703; Y; Y10; Y10S; Y10S174/00; Y10S174/08; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49863; Y10T29/49865; Y10T29/49877
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
126 words
That method of making a flexible axially extendable and contractable bellows having a readily opened and reclosed seam extending lengthwise thereof which comprises securing a pair of seam-forming thermoplastic tapes having interlocking but separable tongues and grooves along the opposite lateral edges of an elongated impervious non-woven sheet of homogenous heat reactive thermoplastic material having a high shrinkage coefficient, closing said seam and telescoping the resulting tubular assembly about a form having a generally annular axially spaced apart ridge forming means with the exterior thereof fully exposed and free of any encircling contractile means, heating said tubular assembly sufficiently to release the internal stresses therein causing said sheet material to heat shrink and contract against said form to form corrugation convolutions thereabout, and removing said form.
Claim 2
Dependent Claim
126 words
That method of making a flexible axially extendable and contractable bellows having a readily opened and reclosed seam extending lengthwise thereof which comprises securing a pair of seam-forming thermoplastic tapes having interlocking but separable tongues and grooves along the opposite lateral edges of an elongated impervious non-woven sheet of homogenous heat reactive thermoplastic material having a high shrinkage coefficient, closing said seam and telescoping the resulting tubular assembly about a form having a generally annular axially spaced apart ridge forming means with the exterior thereof fully exposed and free of any encircling contractile means, heating said tubular assembly sufficiently to release the internal stresses therein causing said sheet material to heat shrink and contract against said form to form corrugation convolutions thereabout, and removing said form.
Claim 3
Dependent Claim
38 words
That method defined in claim 1 characterized in the step of using a flexible wire-like coil as the supporting form and having a pitch corresponding to the pitch of the spiral corrugation desired in the finished tubular product.
Claim 4
Dependent Claim
63 words
That method defined in claim 1 characterized in the steps of securing said seam-forming thermoplastic tapes along the opposite converging edges of a sheet of said heat reactive thermoplastic material shaped to form a conical bellows, closing said seam, and assembling the resulting conical tube coaxially of a tapering wire helix before heating and shrinking said conical tube to form a conical bellows.
Claim 5
Dependent Claim
31 words
That method defined in claim 1 characterized in the step of removing the completed bellows from said ridge forming means by opening said seam from end to end of said bellows.
Claim 6
Dependent Claim
55 words
That method defined in claim 1 characterized in that said wire-like coil has a normal relaxed size and shape fitting generally snugly against the interior surface of said tubular member after said seam is closed and before said member is heated to release the internal stresses therein and responsible for shrinking said member when heated.
Claim 7
Dependent Claim
38 words
That method defined in claim 1 characterized in the step of using a generally conically shaped ridge forming means telescopically assembled into said tubular assembly prior to heating the latter to shrink it against said ridge forming means.
Claim 8
Dependent Claim
23 words
That method defined in claim 1 characterized in the step of providing said bellows with separable reclosable interlocking seam means extending lengthwise thereof.
Claim 9
Dependent Claim
20 words
That method defined in claim 7 characterized in the step of using seam means comprising a pair of thermoplastic tapes.
References Cited (Backward Citations)
US3223565A
Cited
GB862795A
Cited
US3245852A
Cited
US3532571A
Cited
US3568308A
Cited
US3467761A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |