US3923952A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for shaping a normally rigid plastic pipe
Assignee: SIMPSON EXTRUDED PLASTICS Co 900 FOURTH AVE SEATTLE WA 98164 A CORP OF WA
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Filing: 1973-05-23
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Granted: 1975-12-02
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Expires: 1993-05-23
Abstract
Abstract A normally rigid plastic pipe is shaped by softening a selected zone of the pipe, inserting into the softened zone a resiliently deformable mandrel and pressing axially on opposite sides of the mandrel. This expands the mandrel radially into frictional engagement with the softened pipe zone. Contemporaneously the mandrel is shortened axially, thereby correspondingly expanding radially and shortening axially the softened portion of the pipe while proportionately thickening its side walls.
Inventors
- 👤 Branche Harvey W La
- 👤 John C Dimmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:27
CPC Classifications
B; B29; B29C; B29C57/00; B29C57/02; B29C57/04; B29C57/06; Y; Y10; Y10S; Y10S425/00; Y10S425/218
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
135 words
THE METHOD OF SHAPING A NORMALLY RIGID PLASTIC TUBE COMPRISING: A. SOFTENING A SELECTED ZONE OF THE TUBE ADJACENT A RIGID ZONE, B. SURROUNDING THE SOFTENED ZONE WITH A DIE, C. INSERTING A RESILIENTLY DEFORMABLE MANDREL INTO THE SOFTENED ZONE AND THE ADJACENT RIGID ZONE, D. PRESSING AXIALLY AND SIMULTANEOUSLY ON THE OPPOSITE SIDES OF THE MANDREL SUFFICIENTLY TO EXPAND THE MANDREL RADIALLY INTO FRICTIONAL ENGAGEMENT WITH THE SOFTENED ZONE AND WITH THE ADJACENT RIGID ZNE AND, WHILE IN SUCH ENGAGEMENT TO SHORTEN THE MANDREL AXIALLY TO RADIALLY EXPAND THE SOFTENED ZONE INTO FORMING CONTACT WITH THE DIE, THEREBY CORRESPONDINGLY EXPANDING RADIALLY AND SHORTENING AXIALLY SAID SOFTENED ZONE WHILE PROPORTIONATELY THICKENING ITS SIDE WALLS, E. RIGIDIFYING SAID SOFTENED ZONE WHILE IN ITS DIMENSIONALTERED CONDITION, AND F. RELAXING THE MANDREL AND EXTRACTING IT FROM THE TUBE.
Claim 2
Independent Claim
135 words
THE METHOD OF SHAPING A NORMALLY RIGID PLASTIC TUBE COMPRISING: A. SOFTENING A SELECTED ZONE OF THE TUBE ADJACENT A RIGID ZONE, B. SURROUNDING THE SOFTENED ZONE WITH A DIE, C. INSERTING A RESILIENTLY DEFORMABLE MANDREL INTO THE SOFTENED ZONE AND THE ADJACENT RIGID ZONE, D. PRESSING AXIALLY AND SIMULTANEOUSLY ON THE OPPOSITE SIDES OF THE MANDREL SUFFICIENTLY TO EXPAND THE MANDREL RADIALLY INTO FRICTIONAL ENGAGEMENT WITH THE SOFTENED ZONE AND WITH THE ADJACENT RIGID ZNE AND, WHILE IN SUCH ENGAGEMENT TO SHORTEN THE MANDREL AXIALLY TO RADIALLY EXPAND THE SOFTENED ZONE INTO FORMING CONTACT WITH THE DIE, THEREBY CORRESPONDINGLY EXPANDING RADIALLY AND SHORTENING AXIALLY SAID SOFTENED ZONE WHILE PROPORTIONATELY THICKENING ITS SIDE WALLS, E. RIGIDIFYING SAID SOFTENED ZONE WHILE IN ITS DIMENSIONALTERED CONDITION, AND F. RELAXING THE MANDREL AND EXTRACTING IT FROM THE TUBE.
Claim 3
Dependent Claim
30 words
The method of claim 1 wherein the plastic tube comprises a thermoplastic tube and wherein the selected zone of the tube is softened by heating it to a predetermined temperature.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein the selected zone of the tube comprises a tube end and the resultant shaped plastic tube product comprises a plastic tube Having a belled end.
Claim 5
Dependent Claim
51 words
The method of claim 1, including the step of pressing against the end face of the tube remote from the rigid zone, contemporaneously with pressing axially on the opposite sides of the mandrel, to urge said end face toward said rigid zone to augment the axial shortening of said softened zone.
Claim 6
Dependent Claim
37 words
The method of claim 4 wherein the inner end of the mandrel is outwardly flared and including the step of outwardly flaring the softened end zone of the tube upon insertion of the mandrel into the same.
Claim 7
Dependent Claim
35 words
The method of claim 4 wherein the die is provided with an annular recess and including the step of expanding the softened tube into the annular recess to form an annular groove in the tube.
Claim 8
Dependent Claim
99 words
The method of claim 1 wherein the mandrel is in the form of a hollow cylinder and includes a shaft mounting the cylinder, the shaft having in a predetermined location a relieved segment of reduced diameter which in the uncompressed condition of the mandrel is spaced from the mandrel, thereby forming a cavity, and including the step of pressing on the mandrel sufficiently to expand it radially into the cavity, thereby selectively shortening that part of the mandrel which lies opposite the relieved shaft segment, and correspondingly thickening that part of the tube wall engaged by said mandrel part.
Claim 9
Independent Claim
193 words
The method of shaping a normally rigid plastic tube comprising: a. softening an end zone of the tube immediately adjcent a rigid zone, b. surrounding the softened end zone with a die, c. inserting into the softened end zone and the adjacent rigid zone a resiliently deformable mandrel, d. pressing axially and simultaneously on the opposite sides of the mandrel by an amount predetermined to expand the mandrel radially into frictional engagement with the softened tube end zone and with the adjacent rigid zone and while in such engagement to shorten the mandrel axially, e. the mandrel portion in contact witht the said immediately adjacent rigid zone releasably gripping the same and the mandrel portion in contact with the softened end zone expanding the same radially into forming contact with the die, thereby correspondingly expanding radially and shortening axially the softened tube zone while proportionately thickening its side wall, f. while pressing on the opposite sides of the mandrel abutting the end face of the softened end zone against an abutment, g. rigidifying said softened end zone while in its dimensioned-altered condition and h. relaxing the mandrel and removing it from the tube.
Claim 10
Independent Claim
193 words
The method of shaping a normally rigid plastic tube comprising: a. softening an end zone of the tube immediately adjcent a rigid zone, b. surrounding the softened end zone with a die, c. inserting into the softened end zone and the adjacent rigid zone a resiliently deformable mandrel, d. pressing axially and simultaneously on the opposite sides of the mandrel by an amount predetermined to expand the mandrel radially into frictional engagement with the softened tube end zone and with the adjacent rigid zone and while in such engagement to shorten the mandrel axially, e. the mandrel portion in contact witht the said immediately adjacent rigid zone releasably gripping the same and the mandrel portion in contact with the softened end zone expanding the same radially into forming contact with the die, thereby correspondingly expanding radially and shortening axially the softened tube zone while proportionately thickening its side wall, f. while pressing on the opposite sides of the mandrel abutting the end face of the softened end zone against an abutment, g. rigidifying said softened end zone while in its dimensioned-altered condition and h. relaxing the mandrel and removing it from the tube.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |