Patent US3644696A successfully refreshed from Google Patents.
US3644696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for smoothing the inside surface of plastic hose
Assignee: Aerojet Rocketdyne Holdings Inc
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Filing: 1970-08-28
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Granted: 1972-02-22
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Expires: 1990-08-28
Abstract
Abstract The interior surface of thermoplastic hose may contain small crevices, patterns and undercuts which serve to increase the frictional resistance to flow of material through the hose, and which provide sites for the accumulation of material transported therethrough. This is particularly true of plastic hose that is sized and calibrated on a mandrel covered with thin moving tapes which leave tape impressions and ridges on the inside of the hose. This problem is solved by the present invention which utilizes a radiation body which is supported inside of an axially moving hose and which is heated by electrical induction. The heat radiated from the body softens the inside of the hose and allows the surface tension of the plastic to smooth the interior of the hose. Various means are described for anchoring or supporting the radiation body within the hose.
Inventors
- 👤 Philip G Magner Jr
- 👤 Robert W Mitten
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:20
CPC Classifications
B; B29; B29C; B29C59/00; B29C59/16; B29C59/165; B29B; B29B13/00; B29B13/02; B29B13/023; B29B13/024; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/0822; B29C48/00; B29C48/03; B29C48/09; B29K; B29K2995/00; B29K2995/0037; B29K2995/0072; B29L; B29L2023/00; B29L2023/22
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
117 words
An apparatus for smoothing the inner surface of an extruded hollow, substantially tubular thermoplastic product comprising: A. a heating device consisting essentially of 1. a radiant heating unit having an exterior surface a. of a shape to conform to the inner surface of said product and b. of a size less than the inner surface of said product, and 2. an induction coil disposed around said heating unit and spaced therefrom a distance greater than the thickness of said product and B. means to support said heating unit concentrically within said product, and C. means to effect relative movement between said product and said heating unit in a direction parallel to the longitudinal axis of said product.
Claim 2
Independent Claim
117 words
An apparatus for smoothing the inner surface of an extruded hollow, substantially tubular thermoplastic product comprising: A. a heating device consisting essentially of 1. a radiant heating unit having an exterior surface a. of a shape to conform to the inner surface of said product and b. of a size less than the inner surface of said product, and 2. an induction coil disposed around said heating unit and spaced therefrom a distance greater than the thickness of said product and B. means to support said heating unit concentrically within said product, and C. means to effect relative movement between said product and said heating unit in a direction parallel to the longitudinal axis of said product.
Claim 3
Dependent Claim
57 words
an induction coil disposed around said heating unit and spaced therefrom a distance greater than the thickness of said product and B. means to support said heating unit concentrically within said product, and C. means to effect relative movement between said product and said heating unit in a direction parallel to the longitudinal axis of said product.
Claim 4
Dependent Claim
57 words
an induction coil disposed around said heating unit and spaced therefrom a distance greater than the thickness of said product and B. means to support said heating unit concentrically within said product, and C. means to effect relative movement between said product and said heating unit in a direction parallel to the longitudinal axis of said product.
Claim 5
Dependent Claim
16 words
The apparatus of claim 1 wherein the exterior surface of said heating unit is generally cylindrical.
Claim 6
Dependent Claim
17 words
The apparatus of claim 1 wherein said heating unit is joined in axial alignment to a support.
Claim 7
Dependent Claim
18 words
The apparatus of claim 3 wherein the support is anchored against axial movement with respect to the product.
Claim 8
Dependent Claim
42 words
The apparatus of claim 4 wherein said support includes at least two contact rings that are spaced from one another and that are adapted to frictionally contact the inside wall of the hose to maintain the heating unit centered within the product.
Claim 9
Dependent Claim
12 words
The apparatus of claim 3 wherein said support comprises a thermal insulator.
Claim 10
Dependent Claim
18 words
The apparatus of claim 6 wherein said insulator comprises a plurality of axially aligned, spaced apart, ceramic cylinders.
Claim 11
Dependent Claim
109 words
In an apparatus for extruding a hollow thermoplastic substantially tubular product which includes a calibration mandrel having a surface defining the inner contour of the product, said surface composed of a plurality of thin flexible movable tapes and a means for moving the product axially along the mandrel, the improvement comprising: A. a radiant heating unit axially aligned with and spaced from said mandrel said unit being smaller in cross section than the cross section of the mandrel and capable of being heated by induction, and B. an induction coil concentric with the heating unit having an inner diameter that is larger than the outer diameter of the product.
Claim 12
Dependent Claim
109 words
In an apparatus for extruding a hollow thermoplastic substantially tubular product which includes a calibration mandrel having a surface defining the inner contour of the product, said surface composed of a plurality of thin flexible movable tapes and a means for moving the product axially along the mandrel, the improvement comprising: A. a radiant heating unit axially aligned with and spaced from said mandrel said unit being smaller in cross section than the cross section of the mandrel and capable of being heated by induction, and B. an induction coil concentric with the heating unit having an inner diameter that is larger than the outer diameter of the product.
Claim 13
Dependent Claim
18 words
The apparatus of claim 8 wherein the mandrel is separated from the heating unit by a thermal insulator.
Claim 14
Dependent Claim
25 words
The apparatus of claim 9 wherein the thermal insulator comprises a plurality of spaced ceramic cylinders axially aligned with the heating mandrel and the unit.
Claim 15
Dependent Claim
55 words
The apparatus of claim 8 wherein the heating unit is joined to a cylindrical support, which is tethered to the letoff end of the calibration mandrel by a cable, said support including at least two spaced contact rings adapted to frictionally contact the interior wall of the product to maintain the heating unit centered therein.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |