US3852016A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Retractable mandrel for bulging out and forming an annular peripheral groove in plastic tubes
Assignee: SEPEREF TMP SOC EQUIPEMENT
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Filing: 1973-09-12
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Granted: 1974-12-03
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Expires: 1993-09-12
Abstract
Abstract A retractable mandrel enables bulging out and groove forming of tubes of plastic material having large diameters, for exaple 100500 mm. The mandrel is mounted for axial displacement on a carriage and comprises a conical end piece with a frusto-conical tip for receiving a preheated plastic tube. The tube in bulged out on the cylindrical portion of the mandrel and the groove is formed by means of four sector members which in their forming position create complete circular forming rim which is trapezoidal in cross section. When the preheated tube is slid on to the mandrel the sector members are in their retracted position in which the sector members are folded over one another in pairs to each side of a line defined by a first pair of pivot pins displaceable in radial slots. A second pair of pivot pins are received in generally straight parallel slots along with the radial slots are milled in the bottom of a drum. A drive disc is driven by suitable means and mounted for rotation in the end piece and has an S-shaped groove which receives the ends of the second part of pivot pins for sliding movement therein. A spring biases the sector members to their retracted position. Abutment pins and finger cooperate for driving the sector members between retracted and operative positions.
Inventors
- 👤 R Delauzun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:47
CPC Classifications
B; B29; B29C; B29C57/00; B29C57/02; B29C57/04; Y; Y10; Y10S; Y10S425/00; Y10S425/218
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
241 words
A retractable mandrel for bulging out and forming an annular peripheral groove in plastic tubes, comprising a shaft mounted on a carriage, said carriage being displaceable for translatory movement along the longitudinal axis of the shaft, the shaft having a cylindrical end piece with a frusto-conical tip adapted to be inserted in a plastic tube, a drum keyed to the shaft, the shaft passing through the bottom of the drum, four rim-forming sector members adapted to form a complete circular rim, said sector members being pivoted in pairs about a first pair of slidable pivot pins arranged diametrically opposite each other for sliding movement in radial slots in the bottom of the drum, a second pair of slidable pivot pins fixed to diametrically opposed extremities of two of the sector members and passing through parallel slots also in the bottom of the drum, said second pair of pivot pins being received in grooves, said grooves forming together an S with portions extending from the axis of the shaft in a drive disc mounted for rotation, said grooves cooperating with said parallel slots for effecting the outward or expansive movement of the sector members in order to form an annular peripheral groove in the tube in a first direction of rotation of the disc and for retracting or folding the sector members over one another to each side of the line drawn between the axes of said first pair of pivot pins.
Claim 2
Dependent Claim
241 words
A retractable mandrel for bulging out and forming an annular peripheral groove in plastic tubes, comprising a shaft mounted on a carriage, said carriage being displaceable for translatory movement along the longitudinal axis of the shaft, the shaft having a cylindrical end piece with a frusto-conical tip adapted to be inserted in a plastic tube, a drum keyed to the shaft, the shaft passing through the bottom of the drum, four rim-forming sector members adapted to form a complete circular rim, said sector members being pivoted in pairs about a first pair of slidable pivot pins arranged diametrically opposite each other for sliding movement in radial slots in the bottom of the drum, a second pair of slidable pivot pins fixed to diametrically opposed extremities of two of the sector members and passing through parallel slots also in the bottom of the drum, said second pair of pivot pins being received in grooves, said grooves forming together an S with portions extending from the axis of the shaft in a drive disc mounted for rotation, said grooves cooperating with said parallel slots for effecting the outward or expansive movement of the sector members in order to form an annular peripheral groove in the tube in a first direction of rotation of the disc and for retracting or folding the sector members over one another to each side of the line drawn between the axes of said first pair of pivot pins.
Claim 3
Dependent Claim
95 words
A retractable mandrel according to claim 1, wherein two sector members have projections in the vicinity of their respective pivot pins, said drive disc being housed in the end piece for rotation therein and having abutments mounted thereon, the projections bearing against the abutments, a coil spring being received on the shaft, one end of the coil spring bearing against one of the abutments (abutment pins), the other end of the coil spring being received in a hole in the end piece, whereby the coil spring biases the four sector members to the retracted position.
Claim 4
Dependent Claim
47 words
A mandrel according to claim 1, further comprising drive means for the drive disc including a gear wheel mounted for rotation on a sleeve, the sleeve being arranged around the shaft, and a gear rack adapted to be driven by a jack meshing with the gear wheel.
Claim 5
Dependent Claim
30 words
A mandrel according to claim 1, further comprising a jack for effecting the translatory movement of the shaft for inserting and withdrawing the mandrel into and out of the tube.
Claim 6
Dependent Claim
27 words
A retractable mandrel according to claim 1, wherein the cross section of the sector members forming a complete circular rim in their expanded position have trapezoidal cross-sections.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |