|Publication number||US1494128 A|
|Publication date||May 13, 1924|
|Filing date||Jun 11, 1921|
|Priority date||Jun 11, 1921|
|Publication number||US 1494128 A, US 1494128A, US-A-1494128, US1494128 A, US1494128A|
|Original Assignee||Power Specialty Co|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (135), Classifications (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
J. PRHMROSE METHOD AND APPARATUS FOR EXPANDING TUBES Filed June 11 1921 0 8% v n I A v A 7 W awwa wcoz N w i w Patented May 13, 1924.
UNITED STATES 1,494,128 PATENT OFFICE.
JOHN PRIMROSE, OF NEW YORK, N. Y., ASSIGNOR TO POWER SPECIALTY COMPANY, OF NEW YORK, N. Y., A CORPORATION 05F NEW YORK.
unrnon AND arramrus r03, nxrmnme Tunas.
Application filed June 11, 1921. Serial No. 476,761.
' To all whom it may concern Be it known that I, Join: PRIMROSE, a citizen of the United States of America, residing at New York, in the county and State of New York, have invented certain new and useful Improvements in Methods and Apparatus for Expanding Tubes, of which the following is a full, clear, and exact descri tion.
The su ject of this application for Letters Patent is an improvement in tube expanders. The invention is applicable generally for the purpose of expanding or enlarging the internal diameter of metal tubes, but it has and is primarily designed to have a special function in expanding boiler, superheater or other tubes into close contact with the surrounding cast iron rings which are now so largely used to form a casing around such tubes. I shall describe the improvement as adapted and applied to this special purpose.
. In all cases where Wrought steel tubes are enclosed ina corrugated casing of cast iron rings or sections, it is of the first importance to secure and to maintain between the base tube and eatfli of the surrounding rings a perfectly tight fit or union in order to facilitate the proper transfer of heat. This fit is not easy to secure. A slight difference in the internal diameter of the rings, equally slight variations in the thick ness of the walls of the tubes or any inequalities in the surfaces of either leave spaces which very seriously impair the proper heat transfer. Various devices have been constructed and used to correct this objection, but none has met all re uirements, so far as I am aware, because of t e variable pressure between the ex anding surfaces and the inner surface of t e tube which inevitably results from v the conditions of structure and function of the means which have heretofore been used for this purpose.
To overcome these and other objections I have devised a new method and means for expanding the tubes which, broadly stated, involves the ap lication of a constant pressure between t e expanding surfaces and the tubes. This I secure by hydraulic pressure, but the use or application of such pressure for the purpose involves a somewhat difficult problem, which, however, I have solved by the use of a rigid support for the expander which carries movable expanding jaws or surfaces which are forced outwardly by bydraulic pressure and which are designed and adapted to yield, when necessary, against such pressure while always exerting the same or substantially the same expansive force against the tube.
The means which I propose for carrying out this invention are illustrated in the accompanying drawings:
Fig. 1 is a general illustration of the complete apparatus, a tube section which is supposed to be undergoing expansion. being shown in section.
Fig. 2 is a central longitudinal section on an enlarged scale of the expander, and
Fig. 3 is a cross section ofthe same on the line 3-3 of Fig. 2.
For a general understanding of the invention, reference may be had to Fig. 1. In this figure, a section '1 of tube to be expanded has rings or corrugated. sections of cast iron 2 strung over it, which, due to the improvements hereinafter described need not be machined. This tube is then properly supported and the expander 3 drawn through it by means of a hollow rod 4, connected to a cross-head 5, connected by rods 6 to any suitable source of power.
A pneumatic ump or pressureapparatus 7 is connected y a flexible tube 8 to the hollow rod 4, and the fluid under regulated pressure from the (pum is carried to means in or on the expan er or forcing outwardly the jaws which move ove: the internal sur face of the tube 1.
The expander comprises a head or ring 9 screwed or otherwise securely fastened to the end of the rod 4, and a hydraulic cham ber 10 fixed a proper distance back from the head of the rod.- Within the head are a plurality, preferably four, of jaws 11, with suitably rounded ends that fit in sockets in the said head, and are held in place by a slightly elastic band, such as a split steel ring 12, in said head.
A piston 13 is fitted in the chamber 10 and is properly packed in any manner so as to be perfectly fluid tight. Attached to this iston in any proper manner, preferably by screwing into it is a sleeve 14, which slides over the rod 4. The end of this sleeve is conical and provided with raceways for balls 15 which run therein between the sleeve and corresponding Ways in the conical inner surfaces of the jaws 11.
, face of the tube 1 withthe pro er and pres determined pressure. When t e expander as a whole is thus adjusted and drawn through the tube in the direction indicated by the arrows, this pressure forces out the walls of the tube into close union with the inner walls of the rings 2.
I have shown these rings as of dilferent lengths and of varying internal diameters, but this has no effect upon the degree of exansion. When the jaws pass a ring of en arged diameter, the pressure, remaining constant, forces the tube outwardly a sufli-' cient amount to make a close fit. Should the ring be of normal or reduced diameter the amount of expansion is correspondingly decreased, and,the jaws, still under the same pressure, yield to accommodate such reduced diameter. Should a dent or irregularity occure at any point in the tube, as shown, for example, at 16, it will be smoothed out by the expander.
One of thechie merits of this device resides in the fact that the tube is neither cut nor injured, whatever the conditions may be. In other'words, with the means heretofore employed, great care had to be exercised when irregularities in the rings or tube made necessary more than the least amount of expansion to prevent cutting or injuring the tube, but with this device this danger is entirely eliminated.
While the drawing, for purposes of illustration, shows abnormal irregularities in the rings, it shows how by the means herein described even such irregularities may be fully compensated for and overcome.
The specific construction of the means for carrying out this invention may be greatly varied, and I do not regard them as of the essence of the invention.
What I claim is:
1. The method herein described of expanding metal tubes which consists in drawing through the same an expander having movable parts, and maintaining the movable expanding surfaces of the same against the inner surface of the tube by uniform hydraulic pressure said pressure being maintained uniform during any movement of the movable parts of the expander.
2. A tube expander having movable expanding sur aces, in combination with means for forcing them into contact with the inner surface of the tube, and means for maintaining said contact under a uniform predetermined hydraulic pressure while "the tube is being expanded.
3. A tube expander. comprisin an element for drawing an ex ander t rou h a tube, an expander carrie thereby and aving movable expanding surfaces, a hydraulic pressure device carried by said element, a piston in said device, and means connected to said piston for forcing said expandin surfaces against the tube to be expande and maintaining the same constantly a ainst the inner wall of the tube substantially as described.
4. A tube expander having movable expandin surfaces, in combination with a hydrau ic pressure device carried by said expander, a piston in said device, a mechanical device connected with the piston thereof and en aging the expanding surfaces and adapter? to-force the same into contact with the inner surface of the tube and maintain such contact with a constant pressure predetermined by the pressure inthe hydraulic pressure devlce.
In testimony whereof I hereto affix my signature. 1
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US2877822 *||Aug 24, 1953||Mar 17, 1959||Phillips Petroleum Co||Hydraulically operable reciprocating motor driven swage for restoring collapsed pipe|
|US3280608 *||Jul 28, 1959||Oct 25, 1966||Parilla Arthur R||Incremental tube or vessel expander|
|US3785193 *||Apr 10, 1971||Jan 15, 1974||Kinley J||Liner expanding apparatus|
|US3868754 *||Dec 14, 1973||Mar 4, 1975||Hatsuo Kawano||Method of manufacturing a finned-tube heat exchanger|
|US4581801 *||Dec 9, 1983||Apr 15, 1986||Westinghouse Electric Corp.||Sleeving method|
|US4813262 *||Oct 26, 1987||Mar 21, 1989||Kabushiki Kaisha Mihama Seisakusho||Method for forming loop-shaped starting pieces such as metallic binding bands into prescribed final shapes|
|US4831863 *||Mar 25, 1987||May 23, 1989||Kabushiki Kaisha Mihama Seisakusho||Apparatus for forming loop-shaped starting pieces such as metallic binding bands into prescribed final shapes|
|US4866966 *||Aug 29, 1988||Sep 19, 1989||Monroe Auto Equipment Company||Method and apparatus for producing bypass grooves|
|US5502997 *||Dec 19, 1994||Apr 2, 1996||Carrier Corporation||Gripper and mandrel assembly for tube bender|
|US5794702 *||Aug 16, 1996||Aug 18, 1998||Nobileau; Philippe C.||Method for casing a wellbore|
|US6012523 *||Nov 25, 1996||Jan 11, 2000||Petroline Wellsystems Limited||Downhole apparatus and method for expanding a tubing|
|US6823943||Apr 15, 2003||Nov 30, 2004||Bemton F. Baugh||Strippable collapsed well liner|
|US6976541||Jan 22, 2003||Dec 20, 2005||Shell Oil Company||Liner hanger with sliding sleeve valve|
|US7011161||Oct 1, 2002||Mar 14, 2006||Shell Oil Company||Structural support|
|US7021390||Apr 18, 2003||Apr 4, 2006||Shell Oil Company||Tubular liner for wellbore casing|
|US7028770 *||Sep 30, 2002||Apr 18, 2006||Baker Hughes, Incorporated||Tubular expansion apparatus and method|
|US7036582||Oct 1, 2002||May 2, 2006||Shell Oil Company||Expansion cone for radially expanding tubular members|
|US7040396||Feb 20, 2002||May 9, 2006||Shell Oil Company||Apparatus for releasably coupling two elements|
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|US7044221 *||Feb 20, 2002||May 16, 2006||Shell Oil Company||Apparatus for coupling a tubular member to a preexisting structure|
|US7048062||Oct 1, 2002||May 23, 2006||Shell Oil Company||Method of selecting tubular members|
|US7048067||Oct 31, 2000||May 23, 2006||Shell Oil Company||Wellbore casing repair|
|US7055608||Apr 18, 2003||Jun 6, 2006||Shell Oil Company||Forming a wellbore casing while simultaneously drilling a wellbore|
|US7077211||Jan 29, 2004||Jul 18, 2006||Shell Oil Company||Method of creating a casing in a borehole|
|US7077213||Oct 1, 2002||Jul 18, 2006||Shell Oil Company||Expansion cone for radially expanding tubular members|
|US7086475||Oct 1, 2002||Aug 8, 2006||Shell Oil Company||Method of inserting a tubular member into a wellbore|
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|US7100685||Jun 13, 2003||Sep 5, 2006||Enventure Global Technology||Mono-diameter wellbore casing|
|US7117940||Mar 8, 2004||Oct 10, 2006||Shell Oil Company||Expander for expanding a tubular element|
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|US7147053||Aug 13, 2004||Dec 12, 2006||Shell Oil Company||Wellhead|
|US7159665||Jul 19, 2002||Jan 9, 2007||Shell Oil Company||Wellbore casing|
|US7159667||Feb 2, 2004||Jan 9, 2007||Shell Oil Company||Method of coupling a tubular member to a preexisting structure|
|US7168496||Jun 26, 2002||Jan 30, 2007||Eventure Global Technology||Liner hanger|
|US7168499||Sep 10, 2004||Jan 30, 2007||Shell Oil Company||Radial expansion of tubular members|
|US7172019||Mar 7, 2005||Feb 6, 2007||Shell Oil Company||Method and apparatus for forming a mono-diameter wellbore casing|
|US7172021||Nov 3, 2004||Feb 6, 2007||Shell Oil Company||Liner hanger with sliding sleeve valve|
|US7172024||Mar 31, 2003||Feb 6, 2007||Shell Oil Company||Mono-diameter wellbore casing|
|US7174964||Jul 22, 2003||Feb 13, 2007||Shell Oil Company||Wellhead with radially expanded tubulars|
|US7185710||Jun 13, 2003||Mar 6, 2007||Enventure Global Technology||Mono-diameter wellbore casing|
|US7195061||Jun 2, 2005||Mar 27, 2007||Shell Oil Company||Apparatus for expanding a tubular member|
|US7195064||Aug 13, 2003||Mar 27, 2007||Enventure Global Technology||Mono-diameter wellbore casing|
|US7198100||Jun 2, 2005||Apr 3, 2007||Shell Oil Company||Apparatus for expanding a tubular member|
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|US7204007||Mar 4, 2005||Apr 17, 2007||Shell Oil Company||Method and apparatus for forming a mono-diameter wellbore casing|
|US7216701||Jun 1, 2005||May 15, 2007||Shell Oil Company||Apparatus for expanding a tubular member|
|US7225660 *||May 13, 2005||Jun 5, 2007||Kw Industries, Inc.||Apparatus and method for expanding a tube diameter and a pole formed thereby|
|US7231985||Sep 10, 2004||Jun 19, 2007||Shell Oil Company||Radial expansion of tubular members|
|US7234531||Sep 19, 2002||Jun 26, 2007||Enventure Global Technology, Llc||Mono-diameter wellbore casing|
|US7240728||Sep 25, 2001||Jul 10, 2007||Shell Oil Company||Expandable tubulars with a radial passage and wall portions with different wall thicknesses|
|US7240729||Jan 30, 2004||Jul 10, 2007||Shell Oil Company||Apparatus for expanding a tubular member|
|US7243731 *||Aug 1, 2002||Jul 17, 2007||Enventure Global Technology||Apparatus for radially expanding tubular members including a segmented expansion cone|
|US7246667||Sep 27, 2004||Jul 24, 2007||Shell Oil Company||Radial expansion of tubular members|
|US7258168||Jul 27, 2001||Aug 21, 2007||Enventure Global Technology L.L.C.||Liner hanger with slip joint sealing members and method of use|
|US7270188||Nov 22, 2002||Sep 18, 2007||Shell Oil Company||Radial expansion of tubular members|
|US7275601||Sep 28, 2004||Oct 2, 2007||Shell Oil Company||Radial expansion of tubular members|
|US7290605||Dec 10, 2002||Nov 6, 2007||Enventure Global Technology||Seal receptacle using expandable liner hanger|
|US7290616||Jun 26, 2002||Nov 6, 2007||Enventure Global Technology, L.L.C.||Liner hanger|
|US7299881||Sep 27, 2004||Nov 27, 2007||Shell Oil Company||Radial expansion of tubular members|
|US7308755||Mar 4, 2005||Dec 18, 2007||Shell Oil Company||Apparatus for forming a mono-diameter wellbore casing|
|US7325602||Sep 28, 2006||Feb 5, 2008||Shell Oil Company||Method and apparatus for forming a mono-diameter wellbore casing|
|US7350563||Aug 14, 2002||Apr 1, 2008||Enventure Global Technology, L.L.C.||System for lining a wellbore casing|
|US7350564||May 20, 2005||Apr 1, 2008||Enventure Global Technology, L.L.C.||Mono-diameter wellbore casing|
|US7350584 *||Jul 7, 2003||Apr 1, 2008||Weatherford/Lamb, Inc.||Formed tubulars|
|US7357188||Feb 23, 2000||Apr 15, 2008||Shell Oil Company||Mono-diameter wellbore casing|
|US7357190||Sep 28, 2004||Apr 15, 2008||Shell Oil Company||Radial expansion of tubular members|
|US7360591||Apr 17, 2003||Apr 22, 2008||Enventure Global Technology, Llc||System for radially expanding a tubular member|
|US7363690||Mar 2, 2005||Apr 29, 2008||Shell Oil Company||Method and apparatus for forming a mono-diameter wellbore casing|
|US7363691||Mar 3, 2005||Apr 29, 2008||Shell Oil Company||Method and apparatus for forming a mono-diameter wellbore casing|
|US7363984||May 12, 2003||Apr 29, 2008||Enventure Global Technology, Llc||System for radially expanding a tubular member|
|US7377326||Aug 18, 2003||May 27, 2008||Enventure Global Technology, L.L.C.||Magnetic impulse applied sleeve method of forming a wellbore casing|
|US7380593||Nov 27, 2002||Jun 3, 2008||Shell Oil Company||Expandable tubes with overlapping end portions|
|US7398832||May 5, 2003||Jul 15, 2008||Enventure Global Technology, Llc||Mono-diameter wellbore casing|
|US7404444||Aug 18, 2003||Jul 29, 2008||Enventure Global Technology||Protective sleeve for expandable tubulars|
|US7410000||May 20, 2005||Aug 12, 2008||Enventure Global Technology, Llc.||Mono-diameter wellbore casing|
|US7416027 *||Aug 13, 2002||Aug 26, 2008||Enventure Global Technology, Llc||Adjustable expansion cone assembly|
|US7419009||Mar 18, 2005||Sep 2, 2008||Shell Oil Company||Apparatus for radially expanding and plastically deforming a tubular member|
|US7424918||Aug 18, 2003||Sep 16, 2008||Enventure Global Technology, L.L.C.||Interposed joint sealing layer method of forming a wellbore casing|
|US7434618||Jun 1, 2005||Oct 14, 2008||Shell Oil Company||Apparatus for expanding a tubular member|
|US7438132||Apr 23, 2003||Oct 21, 2008||Shell Oil Company||Concentric pipes expanded at the pipe ends and method of forming|
|US7438133||Feb 26, 2004||Oct 21, 2008||Enventure Global Technology, Llc||Apparatus and method for radially expanding and plastically deforming a tubular member|
|US7503393||Jan 26, 2004||Mar 17, 2009||Enventure Global Technology, Inc.||Lubrication system for radially expanding tubular members|
|US7513313||Sep 22, 2003||Apr 7, 2009||Enventure Global Technology, Llc||Bottom plug for forming a mono diameter wellbore casing|
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|US7571774||Aug 18, 2003||Aug 11, 2009||Eventure Global Technology||Self-lubricating expansion mandrel for expandable tubular|
|US7597140||May 3, 2004||Oct 6, 2009||Shell Oil Company||Expansion device for expanding a pipe|
|US7603758||Feb 14, 2001||Oct 20, 2009||Shell Oil Company||Method of coupling a tubular member|
|US7665532||Feb 23, 2010||Shell Oil Company||Pipeline|
|US7712522||Apr 3, 2007||May 11, 2010||Enventure Global Technology, Llc||Expansion cone and system|
|US7739917||Aug 18, 2003||Jun 22, 2010||Enventure Global Technology, Llc||Pipe formability evaluation for expandable tubulars|
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|US7819185||Aug 12, 2005||Oct 26, 2010||Enventure Global Technology, Llc||Expandable tubular|
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|US7918284||Mar 31, 2003||Apr 5, 2011||Enventure Global Technology, L.L.C.||Protective sleeve for threaded connections for expandable liner hanger|
|US9044802 *||Mar 26, 2010||Jun 2, 2015||Weatherford Technology Holdings, Llc||Dynamic load expansion test bench and method of expanding a tubular|
|US20020189816 *||Jul 19, 2002||Dec 19, 2002||Shell Oil Co.||Wellbore casing|
|US20030066655 *||Feb 20, 2002||Apr 10, 2003||Shell Oil Co.||Apparatus for coupling a tubular member to a preexisting structure|
|US20030094277 *||Oct 1, 2002||May 22, 2003||Shell Oil Co.||Expansion cone for radially expanding tubular members|
|US20030094278 *||Oct 1, 2002||May 22, 2003||Shell Oil Co.||Expansion cone for radially expanding tubular members|
|US20030094279 *||Oct 1, 2002||May 22, 2003||Shell Oil Co.||Method of selecting tubular members|
|US20030098162 *||Oct 1, 2002||May 29, 2003||Shell Oil Company||Method of inserting a tubular member into a wellbore|
|US20030116325 *||Dec 18, 2002||Jun 26, 2003||Cook Robert Lance||Liner hanger with standoffs|
|US20030121669 *||Feb 20, 2002||Jul 3, 2003||Shell Oil Co.||Apparatus for releasably coupling two elements|
|US20030150608 *||Sep 30, 2002||Aug 14, 2003||Smith Sidney K.||Tubular expansion apparatus and method|
|US20040045616 *||Apr 18, 2003||Mar 11, 2004||Shell Oil Co.||Tubular liner for wellbore casing|
|US20040045718 *||Jan 22, 2003||Mar 11, 2004||Brisco David Paul||Liner hanger with sliding sleeve valve|
|US20040069499 *||Mar 31, 2003||Apr 15, 2004||Cook Robert Lance||Mono-diameter wellbore casing|
|US20040112589 *||Jun 13, 2003||Jun 17, 2004||Cook Robert Lance||Mono-diameter wellbore casing|
|US20040118574 *||Jun 13, 2003||Jun 24, 2004||Cook Robert Lance||Mono-diameter wellbore casing|
|US20040123983 *||Jul 14, 2003||Jul 1, 2004||Enventure Global Technology L.L.C.||Isolation of subterranean zones|
|US20040123988 *||Jul 22, 2003||Jul 1, 2004||Shell Oil Co.||Wellhead|
|US20040184088 *||Jan 30, 2004||Sep 23, 2004||Panasonic Communications Co., Ltd.||Image data communication device and method|
|US20040188099 *||Jan 29, 2004||Sep 30, 2004||Shell Oil Co.||Method of creating a casing in a borehole|
|US20050000697 *||Jul 7, 2003||Jan 6, 2005||Abercrombie Simpson Neil Andrew||Formed tubulars|
|US20050039910 *||Nov 27, 2002||Feb 24, 2005||Lohbeck Wilhelmus Christianus Maria||Expandable tubes with overlapping end portions|
|US20050098323 *||Apr 18, 2003||May 12, 2005||Shell Oil Co.||Forming a wellbore casing while simultaneously drilling a wellbore|
|US20050144777 *||Mar 4, 2005||Jul 7, 2005||Cook Robert L.||Method and apparatus for forming a mono-diameter wellbore casing|
|US20050194127 *||Mar 8, 2004||Sep 8, 2005||Campo Donald B.||Expander for expanding a tubular element|
|US20050194128 *||Mar 8, 2004||Sep 8, 2005||Campo Donald B.||Expander for expanding a tubular element|
|US20050194129 *||Mar 8, 2004||Sep 8, 2005||Campo Donald B.||Expander for expanding a tubular element|
|US20050194152 *||Mar 8, 2004||Sep 8, 2005||Campo Donald B.||Expander for expanding a tubular element|
|US20060137877 *||Sep 22, 2003||Jun 29, 2006||Watson Brock W||Cutter for wellbore casing|
|US20060260802 *||May 3, 2004||Nov 23, 2006||Filippov Andrei G||Expansion device for expanding a pipe|
|US20070131431 *||Aug 18, 2003||Jun 14, 2007||Mark Shuster||Self-Lubricating expansion mandrel for expandable tubular|
|US20110232355 *||Sep 29, 2011||Evans Merle E||Dynamic load expansion test bench|
|DE4008642A1 *||Mar 17, 1990||Nov 15, 1990||Daimler Benz Ag||Tube expander or dent remover - has mandrel with hinged jaws which are forced apart by nut and screwed spindle|
|U.S. Classification||72/370.8, 72/393, 29/890.46, 29/523|