US4387507A — Method and apparatus for radially expanding tubes

Claim 1

Independent Claim 115 words

An apparatus for generating selected radially expansive pressures with axially separate regions of a tube, said apparatus comprising: at least one primary expander adapted to be inserted in said tube; at least one secondary expander adapted to be inserted in said tube and axially positioned therein with respect to said primary expander, said secondary expander having a larger cross section than said primary expander when considered with reference to a plane passing transversely through said tube; and means for compressing said expanders axially with respect to said tube, thereby producing outwardly directed radial pressure against the interior of said tube and causing said primary expander to produce greater pressure due to its smaller cross-sectional area.

Claim 2

Independent Claim 115 words

An apparatus for generating selected radially expansive pressures with axially separate regions of a tube, said apparatus comprising: at least one primary expander adapted to be inserted in said tube; at least one secondary expander adapted to be inserted in said tube and axially positioned therein with respect to said primary expander, said secondary expander having a larger cross section than said primary expander when considered with reference to a plane passing transversely through said tube; and means for compressing said expanders axially with respect to said tube, thereby producing outwardly directed radial pressure against the interior of said tube and causing said primary expander to produce greater pressure due to its smaller cross-sectional area.

Claim 3

Dependent Claim 25 words

The apparatus of claim 1 wherein: said expanders are ring-shaped; and said means for compressing said expanders includes a draw bar extending through said rings.

Claim 4

Dependent Claim 28 words

The apparatus of claim 2 wherein said means for compressing said means for compressing said expanders further includes a hydraulic cylinder and piston connected to said draw bar.

Claim 5

Dependent Claim 67 words

The apparatus of claim 1 wherein: said expanders are ring-shaped; and said means for compressing said expanders comprises an anvil member adapted to position said apparatus relative to said tube, a hydraulic cylinder connected to said anvil member and fixed in position with respect thereto, a piston movable within said cylinder, and a draw bar connected to said piston for movement therewith extending axially through said expanders.

Claim 6

Dependent Claim 24 words

The apparatus of claim 2 further comprising a sleeve encircled by said primary expander, said draw bar extending through said sleeve and slidable thereon.

Claim 7

Dependent Claim 19 words

The apparatus of claim 1 wherein said expanders are formed of polyurethane and behave as liquid at high pressure.

Claim 8

Independent Claim 86 words

An apparatus for generating radially expansive pressures within axially separated regions of a tube, said apparatus comprising: a draw bar adapted to be inserted in said tube; at least one primary expander encircling said draw bar; at least one secondary expander encircling said draw bar, said secondary expander having a larger cross section than said primary expander when considered with reference to a plane passing transversely there through; and means for actuating said draw bar to thereby compress said expanders axially and expand said expanders radially.

Claim 9

Independent Claim 86 words

An apparatus for generating radially expansive pressures within axially separated regions of a tube, said apparatus comprising: a draw bar adapted to be inserted in said tube; at least one primary expander encircling said draw bar; at least one secondary expander encircling said draw bar, said secondary expander having a larger cross section than said primary expander when considered with reference to a plane passing transversely there through; and means for actuating said draw bar to thereby compress said expanders axially and expand said expanders radially.

Claim 10

Dependent Claim 19 words

The apparatus of claim 7 wherein said means for actuating said draw bar includes a hydraulic cylinder and piston.

Claim 11

Dependent Claim 24 words

The apparatus of claim 7 further comprising a sleeve encircled by said primary expander, said draw bar extending through said sleeve and slidable therein.

Claim 12

Dependent Claim 19 words

The apparatus of claim 7 wherein said expanders are formed of polyurethane and behave as liquid at high pressure.

Claim 13

Independent Claim 159 words

An apparatus for anchoring a tube within a tube sheet in preparation for a subsequent swaging operation, said apparatus comprising: an anvil adapted to engage a surface of said tube sheet and thereby position said apparatus; a hydraulic cylinder connected to said anvil and immovable with respect thereto; a piston movable within said cylinder; a draw bar connected to said piston for movement therewith and adapted to be inserted in said tube; a sleeve in which said draw bar is slidable; a primary expander encircling said sleeve and adapted to be positioned within said tube adjacent to said tube sheet surface; a segmented secondary expander encircling said draw bar, said secondary expander having a larger cross section than said primary expander when considered with respect to a plane passing transversely through said tube; and a head carried by said draw bar to compress said expanders radially and thereby expand said expanders radially upon axial movement of said draw bar.

Claim 14

Independent Claim 159 words

An apparatus for anchoring a tube within a tube sheet in preparation for a subsequent swaging operation, said apparatus comprising: an anvil adapted to engage a surface of said tube sheet and thereby position said apparatus; a hydraulic cylinder connected to said anvil and immovable with respect thereto; a piston movable within said cylinder; a draw bar connected to said piston for movement therewith and adapted to be inserted in said tube; a sleeve in which said draw bar is slidable; a primary expander encircling said sleeve and adapted to be positioned within said tube adjacent to said tube sheet surface; a segmented secondary expander encircling said draw bar, said secondary expander having a larger cross section than said primary expander when considered with respect to a plane passing transversely through said tube; and a head carried by said draw bar to compress said expanders radially and thereby expand said expanders radially upon axial movement of said draw bar.

Claim 15

Dependent Claim 12 words

The apparatus of claim 11 wherein said expanders are made of polyurethane.

Claim 16

Dependent Claim 18 words

The apparatus of claim 11 further comprising a spacer disposed between said primary expander and said secondary expander.

Claim 17

Dependent Claim 28 words

The apparatus of claim 1, 7 or 11 wherein said secondary expander and said primary expander have cylindrical external configurations and are of substantially the same external diameter.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-06-13	1986-12-13	1987-06-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-06-13	1990-12-13	1991-06-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-06-13	1994-12-13	1995-06-14	$7700.00	Window Closed / Lapsed

Method and apparatus for radially expanding tubes

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