Patent US3753635A successfully refreshed from Google Patents.
← Back to Patent Explorer
US3753635A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for precision bending of plastic pipe

Assignee: Individual
•
Filing: 1971-03-25
•
Granted: 1973-08-21
•
Expires: 1991-03-25
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract The specification discloses a process and system for bending plastic pipe to form a desired elbow. In one embodiment there is imposed a super atmospheric pressure within the interior of a segment of the pipe by applying a fluid pressure to the interior of the pipe. The segment of the pipe is heated to its softening temperature and then bent to a predetermined degree of bend while maintaining the fluid pressure on the interior wall to form an elbow with a minimum of distortion of the side walls. Bending is carried out in conformance with a jig. With the formed elbow in the jig, it is cooled while maintaining the fluid pressure on the interior walls. The fluid pressure then is removed and the elbow is released from the jig.

Inventors

  • 👤 L Barnett

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 20:01
CPC Classifications
B; B29; B29C; B29C53/00; B29C53/02; B29C53/08; B29C53/083; B29C33/00; B29C33/34; B29C33/36; B29C53/80; B29L; B29L2023/00; B29L2023/22; Y; Y10; Y10S; Y10S425/00; Y10S425/218

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 549 words
Apparatus for precision bending of plastic conduit comprising: a. a rotatable means for moving a segment of conduit through a plurality of locations for carrying out a variety of cooperating functions, said rotatable means having a plurality of sections, the plurality being at least as great as the number of locations; each section including: i. pressurizing means for establishing a super atmospheric pressure within a segment of conduit, said pressurizing means being connected with a pressurized source of fluid having a pressure regulating means and including cap means for emplacement at each end of said segment of conduit for controlling flow of fluid at each end of said segment of conduit; said pressurizing means being operable to maintain the super atmospheric pressure throughout said plurality of locations as said rotatable means is rotated therethrough; ii. clamping means for clamping each end of said segment of conduit, said clamping means having a fixed portion that is fixedly carried by said section, and a movable portion that is movable along a predetermined arcuate path so as to effect a desired degree of bend and desired shape of said segment of conduit; iii. jig means having an interior wall of a desired finish for effecting an elbow having a desired finished surface, and comprising at least an interior jig means having a desired degree of bend disposed intermediate said fixed portion and said movable portion of said clamp means; iv. automatic bending means connected with said movable portion of said clamping means for bending said segment of conduit responsive to an actuation means, said bending means having holding means for holding a desired degree of bend once attained; and v. stop means for limiting the degree of bending that is automatically effected by said bending means; b. loading and unloading location for emplacing said segment of conduit within said clamping means in a section and connecting said pressurizing means and for releasing said pressurizing means and taking a formed elbow from said clamping means; said loading and unloading location in combination with each said section including: i. means for releasing the pressure from within said conduit and disconnecting said pressurizing means therefrom; ii. means for releasing, respectively, said holding means, said bending means, and said clamping means for taking a formed elbow therefrom; and iii. means for reconnecting said pressurizing means with a subsequent conduit and establishing pressure therewithin; c. heating location including heating means and temperature controlling means disposed peripherally downstream of said loading and unloading location for heating said segment of conduit intermediate its ends to its softening temperature; d. heating and bending location disposed peripherally downstream of said heating location for bending the segment of conduit at its softening temperature to form a precision elbow; said heating and bending location including: i. a heating means for maintaining said segment of conduit at its softening temperature; and ii. actuation means for automatically actuating said bending means to bend the softened segment of conduit into conformance with said jig means and said stop means and into a precise degree of bend and shape; and e. at least one cooling location having means for subjecting said precision elbow to a cooling fluid to cool it below its softening temperature and into an inflexible state before it reaches said loading and unloading locations.
Claim 2
Dependent Claim 549 words
Apparatus for precision bending of plastic conduit comprising: a. a rotatable means for moving a segment of conduit through a plurality of locations for carrying out a variety of cooperating functions, said rotatable means having a plurality of sections, the plurality being at least as great as the number of locations; each section including: i. pressurizing means for establishing a super atmospheric pressure within a segment of conduit, said pressurizing means being connected with a pressurized source of fluid having a pressure regulating means and including cap means for emplacement at each end of said segment of conduit for controlling flow of fluid at each end of said segment of conduit; said pressurizing means being operable to maintain the super atmospheric pressure throughout said plurality of locations as said rotatable means is rotated therethrough; ii. clamping means for clamping each end of said segment of conduit, said clamping means having a fixed portion that is fixedly carried by said section, and a movable portion that is movable along a predetermined arcuate path so as to effect a desired degree of bend and desired shape of said segment of conduit; iii. jig means having an interior wall of a desired finish for effecting an elbow having a desired finished surface, and comprising at least an interior jig means having a desired degree of bend disposed intermediate said fixed portion and said movable portion of said clamp means; iv. automatic bending means connected with said movable portion of said clamping means for bending said segment of conduit responsive to an actuation means, said bending means having holding means for holding a desired degree of bend once attained; and v. stop means for limiting the degree of bending that is automatically effected by said bending means; b. loading and unloading location for emplacing said segment of conduit within said clamping means in a section and connecting said pressurizing means and for releasing said pressurizing means and taking a formed elbow from said clamping means; said loading and unloading location in combination with each said section including: i. means for releasing the pressure from within said conduit and disconnecting said pressurizing means therefrom; ii. means for releasing, respectively, said holding means, said bending means, and said clamping means for taking a formed elbow therefrom; and iii. means for reconnecting said pressurizing means with a subsequent conduit and establishing pressure therewithin; c. heating location including heating means and temperature controlling means disposed peripherally downstream of said loading and unloading location for heating said segment of conduit intermediate its ends to its softening temperature; d. heating and bending location disposed peripherally downstream of said heating location for bending the segment of conduit at its softening temperature to form a precision elbow; said heating and bending location including: i. a heating means for maintaining said segment of conduit at its softening temperature; and ii. actuation means for automatically actuating said bending means to bend the softened segment of conduit into conformance with said jig means and said stop means and into a precise degree of bend and shape; and e. at least one cooling location having means for subjecting said precision elbow to a cooling fluid to cool it below its softening temperature and into an inflexible state before it reaches said loading and unloading locations.
Claim 3
Dependent Claim 20 words
The apparatus of claim 1 wherein said cooling location comprises a gaseous cooling location and a chilled liquid cooling location.
Claim 4
Dependent Claim 44 words
The apparatus of claim 2 wherein said gaseous cooling location includes a second actuation means for permitting flow of gas through the interior of said conduit at super atmospheric pressure; and includes means for circulating cooling gas on the exterior of said precision elbow.
Claim 5
Dependent Claim 16 words
The apparatus of claim 2 wherein said chilled liquid cooling location includes a chilled liquid bath.
Claim 6
Dependent Claim 16 words
The apparatus of claim 2 wherein said chilled liquid cooling location includes a chilled liquid spray.
Claim 7
Dependent Claim 33 words
The apparatus of claim 1 wherein said pressurizing means is connected with said source of fluid via a universal coupling means so as to be rotatably connected therewith throughout said plurality of locations.
Claim 8
Dependent Claim 72 words
The apparatus of claim 1 wherein said section of said rotatable means contains an exterior jig means and a fitting means for fitting said exterior jig means about said segment of softened conduit and in conforming relationship with said interior jig means to form an enclosing mold against which said super atmospheric pressure can conformingly press the walls of said softened precision elbow for more nearly exact definition of said precision elbow.
Claim 9
Dependent Claim 43 words
The apparatus of claim 1 wherein said rotatable means is rotatable about a horizontal axis to rotate said plurality of sections in a vertical plane through said loading and unloading location, said heating location, said heating and bending location, and said cooling location.
Claim 10
Dependent Claim 43 words
The apparatus of claim 1 wherein said rotatable means is rotatable about a vertical axis to rotate said plurality of sections in a horizontal plane through said loading and unloading location, said heating location, said heating and bending location, and said cooling location.
Claim 11
Dependent Claim 40 words
The apparatus of claim 1 comprising means for removably supporting said jig means whereby said jig means may be readily interchanged with different jig means to allow conduits of different sizes to be bent and at different degrees of bend.

References Cited (Backward Citations)

US1877629A Cited
US2433055A Cited
US3362860A Cited
US3184796A Cited
US3352960A Cited
US3671161A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-08-20 1977-02-19 1977-08-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-08-20 1981-02-19 1981-08-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-08-20 1985-02-19 1985-08-21 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag