Patent US3581548A successfully refreshed from Google Patents.
US3581548A
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US
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Machine and method for expanding sheet metal pipe to noncircular cross section
Assignee: United Mcgill Corp
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Filing: 1968-10-03
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Granted: 1971-06-01
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Expires: 1988-10-03
Abstract
Abstract A method of expanding or stretching and a machine to expand or stretch sheet metal pipe into flat oval cross section pipe as well as the resulting length of small diameter expanded, noncircular cross section pipe. The machine has a vertical operating wedge reciprocably disposed between inclined expansion track and mandrel assemblies over which sections of initially round pipe are placed. Power components for the machine are under the working parts and are preferably located below ground level. The method of operation results in expansion of a length of sheet metal pipe up to twice the length of the expansion mandrels into flat oval cross section. The pipe is placed over the mandrels and at least one-half its length stretched, the pipe then being reversed with its other end placed over the mandrels, properly located and stretched in coextensive relationship to the other previously stretched portion of the pipe. The wedge is reciprocated by a hydraulic motor (ram), the inclined tracks are guided for lateral displacement at their lower ends and, by cooperating linkage, will be positively slid back into juxtaposition when the wedge is withdrawn to a retracted position.
Inventors
- 👤 Evan Lilygren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:07
CPC Classifications
B; B21; B21D; B21D22/00; B21D22/02; B21D22/025; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12333
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
200 words
A method of making noncircular cross section tubing by converting a length of circular cross section sheet metal tubing into noncircular cross section tubing comprising the steps of: locating the length of tubing upon a shorter length expansible mandrel assembly extending inside one end of the tubing for a distance greater than half the length of the tubing; deforming said more than half the length of the tubing into the desired noncircular cross section by expanding the mandrel assembly uniformly throughout its length; restoring the mandrel assembly from its expandeD condition to release the tubing; removing and reversing the length of tubing and locating its nonexpanded end upon the mandrel assembly with the mandrel assembly extending inside the other end of the length of tubing for a distance greater than the nonexpanded portion of the length of the tubing with the previously expanded portion of the tubing properly aligned with the direction in which the mandrel assembly expands; deforming the remaining undeformed portion of the length of tubing by again expanding the mandrel assembly uniformly through out its length; again restoring the mandrel assembly from its expanded condition; and removing the completely deformed length of tubing from the mandrel assembly.
Claim 2
Independent Claim
200 words
A method of making noncircular cross section tubing by converting a length of circular cross section sheet metal tubing into noncircular cross section tubing comprising the steps of: locating the length of tubing upon a shorter length expansible mandrel assembly extending inside one end of the tubing for a distance greater than half the length of the tubing; deforming said more than half the length of the tubing into the desired noncircular cross section by expanding the mandrel assembly uniformly throughout its length; restoring the mandrel assembly from its expandeD condition to release the tubing; removing and reversing the length of tubing and locating its nonexpanded end upon the mandrel assembly with the mandrel assembly extending inside the other end of the length of tubing for a distance greater than the nonexpanded portion of the length of the tubing with the previously expanded portion of the tubing properly aligned with the direction in which the mandrel assembly expands; deforming the remaining undeformed portion of the length of tubing by again expanding the mandrel assembly uniformly through out its length; again restoring the mandrel assembly from its expanded condition; and removing the completely deformed length of tubing from the mandrel assembly.
Claim 3
Dependent Claim
42 words
A method of making noncircular cross section tubing as claimed in claim 1 wherein the final noncircular cross section is flat oval and wherein the circular cross section tubing initially is selected from standard diameter sheet metal tubing 5 inches and larger.
Claim 4
Dependent Claim
30 words
A method of making noncircular cross section tubing as claimed in claim 1, wherein the length of tubing is placed on the mandrel assembly with its elongated axis disposed vertically.
Claim 5
Dependent Claim
26 words
A method of making noncircular cross section tubing as claimed in claim 1, wherein the tubing is initially partially flattened from its original circular cross section.
Claim 6
Dependent Claim
39 words
A length of internally, expansion deformed, flat oval cross section spiral tubing, having two substantially parallel flat wall portions and curved end wall portions made from helical seam, initially round tubing having an initial diameter less than 14 inches.
Claim 7
Dependent Claim
39 words
A length of internally, expansion deformed, flat oval cross section spiral tubing, having two substantially parallel flat wall portions and curved end wall portions made from helical seam, initially round tubing having an initial diameter less than 14 inches.
Claim 8
Dependent Claim
123 words
An expansible mandrel machine for converting sheet metal tubing having an initial diameter which may be as small as 6 inches by cross section expansion into noncircular cross section tubing comprising: a pair of elongated vertically disposed parallel tube former means having a length greater than half the length of the tubing to be converted; and force applying means including a vertically shiftable means disposed between said parallel former means and adapted to apply uniform pressure transverse to the elongate axis of and throughout the length of said parallel former means to move said former means apart while maintaining their parallelism when said shiftable means is shifted in one direction and including means to retract said two parallel former means toward each other.
Claim 9
Dependent Claim
123 words
An expansible mandrel machine for converting sheet metal tubing having an initial diameter which may be as small as 6 inches by cross section expansion into noncircular cross section tubing comprising: a pair of elongated vertically disposed parallel tube former means having a length greater than half the length of the tubing to be converted; and force applying means including a vertically shiftable means disposed between said parallel former means and adapted to apply uniform pressure transverse to the elongate axis of and throughout the length of said parallel former means to move said former means apart while maintaining their parallelism when said shiftable means is shifted in one direction and including means to retract said two parallel former means toward each other.
Claim 10
Dependent Claim
65 words
An expansible mandrel machine as defined in claim 6, wherein each of said pair of former means includes a side rail, said side rails having vertically converging track surfaces extending from adjacent their lowermost ends to adjacent their upper ends; and said vertically shiftable means comprises a wedge longer than said side rails having converging side faces complementary to and engaging said facing track surfaces.
Claim 11
Dependent Claim
48 words
An expansible mandrel machine as defined in claim 6, wherein means on said former means and means on said vertically shiftable means are interconnected to provide said means for retracting said former means toward each other upon movement of said vertically shiftable means in its said other direction.
Claim 12
Dependent Claim
45 words
An expansible mandrel machine as defined in claim 8, wherein said means for retracting said former means comprise pin and slot connections with pins mounted on said former means and convergent slots provided in said vertically shiftable means and into which slots said pins project.
Claim 13
Dependent Claim
37 words
An expansible mandrel machine as defined in claim 6, wherein said force applying means includes a dual acting reciprocating piston motor with an upwardly projecting piston rod secured to the lower end of said vertically shiftable means.
Claim 14
Dependent Claim
74 words
An expansible mandrel machine as defined in claim 6, including a main support means at the lower end of said former means; and means connecting said former means to said support means in a manner preventing movement of said former means in the direction of movement of said vertically shiftable means and permitting controlled movement of said former means in A predetermined path normal to the direction of movement of said vertically shiftable means.
Claim 15
Dependent Claim
39 words
An expansible mandrel machine as defined in claim 11, wherein said support means has a central passage and both of said former means and said vertically shiftable means project from below said support means up through said central passage.
Claim 16
Dependent Claim
78 words
An expansible mandrel machine as defined in claim 12, wherein said means which connect said former means to said support means comprises an end bracket means secured to the lower end of each of said pair of former means and disposed against the under surface of said support means, and guide ways secured under said support means in embracing and guiding relationship with said end bracket means to maintain them against the under surface of said support means.
Claim 17
Dependent Claim
30 words
An expansible mandrel machine as defined in claim 13, wherein means are provided for injection lubrication of the relatively shiftable surfaces of said brackets, said ways and said support means.
Claim 18
Dependent Claim
37 words
An expansible mandrel machine as defined in claim 11, wherein said force applying means includes a vertically reciprocating piston motor and a rigid suspension assembly secures said motor in depending relationship under and to said support means.
Claim 19
Dependent Claim
23 words
An expansible mandrel machine as defined in claim 11, including means for variably controlling the length of work stroke of said force-applying means.
Claim 20
Dependent Claim
61 words
An expansible mandrel machine as defined in claim 6, wherein each of said pair of former means comprises a vertical side rail engaged on its inner side by said vertically shiftable means, at least one mandrel form member disposed parallel to and at the outer side of each said rail and means interconnecting said form members with their associated side rails.
Claim 21
Dependent Claim
39 words
An expansible mandrel machine as defined in claim 17, wherein at least one of the pair of former means comprises more than one interconnected form member, in laterally stacked arrangement, interconnected with each other and the associated side rail.
Claim 22
Dependent Claim
96 words
An expansible mandrel machine as defined in claim 17, wherein at least the outermost of said form members have an outer half cylindrical surface the axes of which are disposed vertical and parallel when all form members are interconnected with their associated side rail, and said outermost of said form members on the pair of side rails constitute a matched pair selected from a group of matched pairs of half cylindrical form members, each matched pair having a different diameter corresponding to the inside diameter of the minor axis of a standard size flat oval tubing.
Claim 23
Dependent Claim
175 words
An expansible mandrel machine for converting sheet metal tubing by cross section expansion into noncircular cross section tubing comprising: support structure; a pair of elongate parallel tube former means having a length greater than half the length of the tubing to be converted; and force-applying means including a reciprocably shiftable means disposed between said parallel former means and adapted to apply uniform pressure transverse to the elongate axis of and throughout the length of said parallel former means to move said former means apart while maintaining their parallelism when said shiftable means is shifted in one direction and including means to retract said two parallel former means toward each other; each of said pair of former means including a side rail, said side rails being mounted adjacent one of their ends on said support structure and having converging track surfaces extending from adjacent their mounted ends to adjacent their other ends; and said shiftable means comprises a wedge longer than said side rails having converging side faces complementary to and engaging said facing track surfaces.
Claim 24
Dependent Claim
175 words
An expansible mandrel machine for converting sheet metal tubing by cross section expansion into noncircular cross section tubing comprising: support structure; a pair of elongate parallel tube former means having a length greater than half the length of the tubing to be converted; and force-applying means including a reciprocably shiftable means disposed between said parallel former means and adapted to apply uniform pressure transverse to the elongate axis of and throughout the length of said parallel former means to move said former means apart while maintaining their parallelism when said shiftable means is shifted in one direction and including means to retract said two parallel former means toward each other; each of said pair of former means including a side rail, said side rails being mounted adjacent one of their ends on said support structure and having converging track surfaces extending from adjacent their mounted ends to adjacent their other ends; and said shiftable means comprises a wedge longer than said side rails having converging side faces complementary to and engaging said facing track surfaces.
References Cited (Backward Citations)
US1493502A
Cited
US3266285A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |