US2744269A - Pipe threading die head assembly - Google Patents

Pipe threading die head assembly Download PDF

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Publication number
US2744269A
US2744269A US257232A US25723251A US2744269A US 2744269 A US2744269 A US 2744269A US 257232 A US257232 A US 257232A US 25723251 A US25723251 A US 25723251A US 2744269 A US2744269 A US 2744269A
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United States
Prior art keywords
die head
pipe
thread
head assembly
mandrel
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US257232A
Inventor
Karl K Kerr
Jr Edward J Kleber
Samuel H S Raub
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Union Carbide Corp
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Union Carbide and Carbon Corp
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Publication date
Application filed by Union Carbide and Carbon Corp filed Critical Union Carbide and Carbon Corp
Priority to US257232A priority Critical patent/US2744269A/en
Priority to US555090A priority patent/US2808599A/en
Application granted granted Critical
Publication of US2744269A publication Critical patent/US2744269A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23G—THREAD CUTTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTION THEREWITH
    • B23G1/00—Thread cutting; Automatic machines specially designed therefor
    • B23G1/22—Machines specially designed for operating on pipes or tubes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T408/00—Cutting by use of rotating axially moving tool
    • Y10T408/55—Cutting by use of rotating axially moving tool with work-engaging structure other than Tool or tool-support
    • Y10T408/557—Frictionally engaging sides of opening in work
    • Y10T408/558—Opening coaxial with Tool
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T408/00—Cutting by use of rotating axially moving tool
    • Y10T408/89—Tool or Tool with support
    • Y10T408/904—Tool or Tool with support with pitch-stabilizing ridge
    • Y10T408/9044—Tool or Tool with support with pitch-stabilizing ridge including cutting teeth of different width
    • Y10T408/9045—Tool or Tool with support with pitch-stabilizing ridge including cutting teeth of different width and different root circles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T408/00—Cutting by use of rotating axially moving tool
    • Y10T408/89—Tool or Tool with support
    • Y10T408/909—Having peripherally spaced cutting edges
    • Y10T408/9095—Having peripherally spaced cutting edges with axially extending relief channel
    • Y10T408/9097—Spiral channel

Definitions

  • This invention relates to die heads for pipe threading, and, more particularly, to die heads for threading carbon and graphite pipe.
  • pipe threading has been accomplished by use of standard dies wherein the cutting teeth have a constant pitch and pitch diameter.
  • the first few teeth of each chaser of the standard die heads are truncated to form a throat, so that the thread is generated by a series of teeth of the same pitch diameter, each tooth cutting by that amount which it projects inwardly further than the preceding tooth.
  • the threads generated are scratched, scored and ragged due to the fact that each succeeding tooth cuts deeper without cleaning up any of the thread-surface generated by the preceding tooth.
  • Another object is to provide a die head that will generate a pipe thread having a gradually stepped runout of decreasing pitch diameter in the region of furthest threading.
  • a further object is to provide for a die head assembly that will generate pipe threads without requiring an external force to hold the assembly to the pipe once it has been set thereon preparatory to the commencement of the threading operation.
  • a still further object is to provide a die head that will generate smooth threads on pipe made of highly abrasive material, such as impervious carbon and graphite.
  • Fig. 1 is a perspective view of a die head assembly for hand threading embodying the present invention, part being broken away;
  • Fig. 2 is a perspective view of a chaser removed from the die head of Fig. 1;
  • Fig. 3 is a partial sectional view of a partly threaded pipe illustrating the effect of variations in cutting tooth pitch diameter
  • Fig. 4 is a longitudinal sectional view of a pipe showing the depth and shape of cut obtained by successive cutting teeth of a die head embodying the present invention
  • Fig. 5 is a developed view of a pipe thread cut by a die head of the present invention, illustrating the depths of thread generated as the chasers pass over a given section of pipe;
  • Fig. 6 is a longitudinal sectional view of the hand die head of Fig. l. with. mandrel inserted into a pipe and the expanding arbor securely holding the die head to the pipe in readiness for the commencement of the threading operation;
  • Fig. 7 is a partial longitudinal sectional view of the hand die head of Fig. 1 and engaged pipe, wherein said die head has completed the threading operation and is in the fully threaded position.
  • a die head assembly embodying the present invention is shown in Figs. 1, 6 and 7, and comprises a steppeddiameter cylindrical mandrel 1, having at one end a relatively large diameter knurled handle 2, a relatively reduced diameter pipe-grasping arbor section 3 at the opposite end, and a threaded section 4 of relatively intermediate diameter between them.
  • the pipe-grasping arbor carries a sleeve of rubber or other suitable material 5 which expands to grasp the internal surface of pipe P as wing nut 6 is tightened causing a retraction of the front plug of mandrel 1.
  • the hollow cylindrical die head 7 is mounted axially on the mandrel sothat the die head moves along mandrel threads 8 as it is rotated.
  • the die head 7 supports four radially-positioned chasers 10 which are v maintain the proper thread pitch for the cutting teeth as the cutting teeth generate threads on the work.
  • a front plate 14 holds the chasers in the die head.
  • the chasers are so constructed that the sizing nibs .turn down the outside diameter of pipe P to the proper major diameter for threading before the commencement of the threading operation. Then, as the head is further advanced along the mandrel, the first cutting tooth cuts approximately twenty-five per cent full thread depth.
  • All cutting teeth on the chasers of the die head of the present invention are of full tooth shape but of varying pitch diameters. Of the total of eight cutting teeth on the embodiment of the present invention shown in the drawings, only five actually out when the die head is new. Asthese teeth become dull with use and are sharpened, the pitch diameters are increased and teeth six, seven and eight take on work progressively.
  • the pipe to be threaded is suitably secured in a vise.
  • the die head 7 is threaded back against the rear shoulder 15 of the mandrel 1.
  • the arbor section 3 is then inserted into the pipe up to the front shoulder 16 of the mandrel, and, while the knurled handle 2 of the mandrel 1 is held stationary, the wing nut 6 on the end of the knurled handle is tightened. This causes an expansion of the rubber arbor section 3 and securely holds the die head assembly to the pipe, as is shown in Fig. 6.
  • the actual threading operation is then begun by turning the knobbed handle 9 in a clockwise direction. This is continued until the head 7 contacts stop 17 which resists further turning. When it is desired to generate greater lengths of thread the stop 17 is removed so that the die head 7 may move oil mandrel 1 and continue threading the pipe to any desired point.
  • the die head assembly may be removed after the threading operation is completed by backing die head 7 oil? the pipe with a counterclockwise motion, loosening the wing nut 6 on the handle end of mandrel 1 and removing the mandrel from the pipe.
  • the thread generated by the die head of the present invention has a gradually stepped runout and not a relief of full depth such as on a standard lathe-chased thread and is, therefore, considerably stronger than a standard lathe-chased thread.
  • Patented May 8, 1956 3 such as impervious carbon or graphite pipe, it has been found advantageous to employ nibs and cutting teeth of sintered carbide, silver soldered, brazed, or otherwise secured into position on the chaser.
  • a die head assembly for threading impervious carbon and graphite pipe to any desired length comprising a stepped-diameter cylindrical mandrel having .a threaded portion near the rear end thereof, a reduced diameter expandable arbor section at the front end thereof for insertion into said pipe, and means for expanding said arbor section to engage the interior of said pipe; 21 die head having at least four chasers symmetrically and circumferentially disposed and rigidly secured thereto, and a plurality of pusher teeth von each of said chasers for rotatably engaging said threaded portion of said mandrel; at least one individually-mounted single cutting tooth rigidly secured to each of said .chasers and projecting inwardly immediatelytin advance of said pusher teeth to cut said pipe, there being a total of at least five such cutting teeth positioned to cut symmetrically to full thread profile and successive cutting teeth arranged to cut progressively deeper whereby a thread of full depth is developed on said pipe in less than one-and-one-half revolutions of said die head; said die head

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Metal Extraction Processes (AREA)

Description

y 8 1956 K. K. KERR ET AL 2,744,269
PIPE THREADING DIE HEAD ASSEMBLY Filed Nov. 20, 1951 2 he 2 INVENTORS KARL K. KERR EDWARD J. KLEBER,JR. BSYAMUEL H. S. RAUB ATTORNEY United States Patent PIPE THREADING DIE HEAD ASSEMBLY Karl K. Kerr, Lakewood, Ohio,,Edward J. Kleber, Jr.,
Niagara Falls, N. Y., and Samuel H. S. Raub, Cleveland, Ohio, assignors to Union Carbide and Carbon Corporation, a corporation of New York Application November 20, 1951, Serial No. 257,232
1 Claim. (Cl. 10-123) This invention relates to die heads for pipe threading, and, more particularly, to die heads for threading carbon and graphite pipe. Heretofore, pipe threading has been accomplished by use of standard dies wherein the cutting teeth have a constant pitch and pitch diameter. The first few teeth of each chaser of the standard die heads are truncated to form a throat, so that the thread is generated by a series of teeth of the same pitch diameter, each tooth cutting by that amount which it projects inwardly further than the preceding tooth. When such dies are used to thread carbon and graphite pipe the threads generated are scratched, scored and ragged due to the fact that each succeeding tooth cuts deeper without cleaning up any of the thread-surface generated by the preceding tooth.
It is an object of the present invention to provide a die head that will generate threads on pipe without crushing, scratching, or damaging the thread surface.
Another object is to provide a die head that will generate a pipe thread having a gradually stepped runout of decreasing pitch diameter in the region of furthest threading.
A further object is to provide for a die head assembly that will generate pipe threads without requiring an external force to hold the assembly to the pipe once it has been set thereon preparatory to the commencement of the threading operation.
A still further object is to provide a die head that will generate smooth threads on pipe made of highly abrasive material, such as impervious carbon and graphite.
Other objects and advantages of this invention will be apparent during the course of the following description.
In the accompanying drawings:
Fig. 1 is a perspective view of a die head assembly for hand threading embodying the present invention, part being broken away;
Fig. 2 is a perspective view of a chaser removed from the die head of Fig. 1;
Fig. 3 is a partial sectional view of a partly threaded pipe illustrating the effect of variations in cutting tooth pitch diameter;
Fig. 4 is a longitudinal sectional view of a pipe showing the depth and shape of cut obtained by successive cutting teeth of a die head embodying the present invention;
Fig. 5 is a developed view of a pipe thread cut by a die head of the present invention, illustrating the depths of thread generated as the chasers pass over a given section of pipe;
Fig. 6 is a longitudinal sectional view of the hand die head of Fig. l. with. mandrel inserted into a pipe and the expanding arbor securely holding the die head to the pipe in readiness for the commencement of the threading operation;
Fig. 7 is a partial longitudinal sectional view of the hand die head of Fig. 1 and engaged pipe, wherein said die head has completed the threading operation and is in the fully threaded position.
A die head assembly embodying the present invention is shown in Figs. 1, 6 and 7, and comprises a steppeddiameter cylindrical mandrel 1, having at one end a relatively large diameter knurled handle 2, a relatively reduced diameter pipe-grasping arbor section 3 at the opposite end, and a threaded section 4 of relatively intermediate diameter between them. The pipe-grasping arbor carries a sleeve of rubber or other suitable material 5 which expands to grasp the internal surface of pipe P as wing nut 6 is tightened causing a retraction of the front plug of mandrel 1. The hollow cylindrical die head 7 is mounted axially on the mandrel sothat the die head moves along mandrel threads 8 as it is rotated. In manual operation this rotation of the head may be accomplished by means of handle 9. The die head 7 supports four radially-positioned chasers 10 which are v maintain the proper thread pitch for the cutting teeth as the cutting teeth generate threads on the work. A front plate 14 holds the chasers in the die head.
The chasers are so constructed that the sizing nibs .turn down the outside diameter of pipe P to the proper major diameter for threading before the commencement of the threading operation. Then, as the head is further advanced along the mandrel, the first cutting tooth cuts approximately twenty-five per cent full thread depth.
Subsequent teeth, following at -degree intervals, cut 7 to a progressively greater thread depth with the fifth tooth in sequence cutting to full depth, as shown in Figs. 3, 4, and 5. This means that, when using the embodiment shown in the drawings, full thread depth is attained in one and a quarter turns of the die head after the first tooth has engaged the pipe.
All cutting teeth on the chasers of the die head of the present invention are of full tooth shape but of varying pitch diameters. Of the total of eight cutting teeth on the embodiment of the present invention shown in the drawings, only five actually out when the die head is new. Asthese teeth become dull with use and are sharpened, the pitch diameters are increased and teeth six, seven and eight take on work progressively.
In operation, the pipe to be threaded is suitably secured in a vise. Before using the illustrated assembly, the die head 7 is threaded back against the rear shoulder 15 of the mandrel 1. The arbor section 3 is then inserted into the pipe up to the front shoulder 16 of the mandrel, and, while the knurled handle 2 of the mandrel 1 is held stationary, the wing nut 6 on the end of the knurled handle is tightened. This causes an expansion of the rubber arbor section 3 and securely holds the die head assembly to the pipe, as is shown in Fig. 6. I
The actual threading operation is then begun by turning the knobbed handle 9 in a clockwise direction. This is continued until the head 7 contacts stop 17 which resists further turning. When it is desired to generate greater lengths of thread the stop 17 is removed so that the die head 7 may move oil mandrel 1 and continue threading the pipe to any desired point. The die head assembly may be removed after the threading operation is completed by backing die head 7 oil? the pipe with a counterclockwise motion, loosening the wing nut 6 on the handle end of mandrel 1 and removing the mandrel from the pipe.
The thread generated by the die head of the present invention has a gradually stepped runout and not a relief of full depth such as on a standard lathe-chased thread and is, therefore, considerably stronger than a standard lathe-chased thread. When the die head of the present invention is used for threadinghighly abrasive materials,
Patented May 8, 1956 3 such as impervious carbon or graphite pipe, it has been found advantageous to employ nibs and cutting teeth of sintered carbide, silver soldered, brazed, or otherwise secured into position on the chaser.
What is claimed is:
A die head assembly for threading impervious carbon and graphite pipe to any desired length comprising a stepped-diameter cylindrical mandrel having .a threaded portion near the rear end thereof, a reduced diameter expandable arbor section at the front end thereof for insertion into said pipe, and means for expanding said arbor section to engage the interior of said pipe; 21 die head having at least four chasers symmetrically and circumferentially disposed and rigidly secured thereto, and a plurality of pusher teeth von each of said chasers for rotatably engaging said threaded portion of said mandrel; at least one individually-mounted single cutting tooth rigidly secured to each of said .chasers and projecting inwardly immediatelytin advance of said pusher teeth to cut said pipe, there being a total of at least five such cutting teeth positioned to cut symmetrically to full thread profile and successive cutting teeth arranged to cut progressively deeper whereby a thread of full depth is developed on said pipe in less than one-and-one-half revolutions of said die head; said die head pusher teeth having the same pitch as said cutting teeth and a pitch diameter equal to the pitch diameter of said cutting teeth positioned to cut said pipe to full depth.
References Cited in the file of this patent UNITED STATES PATENTS 196,710 Seigfried Oct. 30, 1877 269,981 Woodbridge Jan. 2, 1883 1,610,087 Hanson Dec. 7, 1926 1,892,904 Robinson et a1. Jan. 3, 1933 2,096,810 Judge Oct. 26, 1937 2,280,013 Stultz Apr. 14, 1942 FOREIGN PATENTS 469,143 Germany Dec. 3, 1928
US257232A 1951-11-20 1951-11-20 Pipe threading die head assembly Expired - Lifetime US2744269A (en)

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US257232A US2744269A (en) 1951-11-20 1951-11-20 Pipe threading die head assembly
US555090A US2808599A (en) 1951-11-20 1955-12-23 Pipe threading die head assembly

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2808599A (en) * 1951-11-20 1957-10-08 Union Carbide Corp Pipe threading die head assembly
US3021538A (en) * 1956-04-16 1962-02-20 Universal Thread Grinding Comp Thread cutting tool with dulled edges on the guide teeth portion
US3093850A (en) * 1959-10-30 1963-06-18 United States Steel Corp Thread chasers having the last tooth free of flank contact rearwardly of the thread crest cut thereby
US3220032A (en) * 1962-04-27 1965-11-30 Balax Inc Thread cutting tap
US3255473A (en) * 1964-01-06 1966-06-14 Joseph J Csiszar Rethreading tool
US3629887A (en) * 1969-12-22 1971-12-28 Pipe Machinery Co The Carbide thread chaser set
US4409868A (en) * 1981-04-13 1983-10-18 The Valeron Corporation Threading tool and method
US20110078897A1 (en) * 2009-10-02 2011-04-07 Christopher John Shahin Stabilizer device for through-hole electrical jacks
US20170028489A1 (en) * 2014-04-08 2017-02-02 Snecma A shaft machining anti-vibration device

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US196710A (en) * 1877-10-30 Improvement in machines for cutting screw-threads
US269981A (en) * 1883-01-02 Self and feedeeick n
US1610097A (en) * 1924-08-25 1926-12-07 Edmond C Joseph Shade and curtain adjusting and supporting means
DE469143C (en) * 1925-12-30 1928-12-03 Hugo Reisiger Fa Thread cutting stock
US1892904A (en) * 1931-11-06 1933-01-03 Robinson Quint Orval Pipe threading device
US2096810A (en) * 1935-09-25 1937-10-26 Greenfield Tap And Dic Corp Thread cutting device
US2280013A (en) * 1941-07-17 1942-04-14 Alfred M Stultz Adjustable pipe threader

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US196710A (en) * 1877-10-30 Improvement in machines for cutting screw-threads
US269981A (en) * 1883-01-02 Self and feedeeick n
US1610097A (en) * 1924-08-25 1926-12-07 Edmond C Joseph Shade and curtain adjusting and supporting means
DE469143C (en) * 1925-12-30 1928-12-03 Hugo Reisiger Fa Thread cutting stock
US1892904A (en) * 1931-11-06 1933-01-03 Robinson Quint Orval Pipe threading device
US2096810A (en) * 1935-09-25 1937-10-26 Greenfield Tap And Dic Corp Thread cutting device
US2280013A (en) * 1941-07-17 1942-04-14 Alfred M Stultz Adjustable pipe threader

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2808599A (en) * 1951-11-20 1957-10-08 Union Carbide Corp Pipe threading die head assembly
US3021538A (en) * 1956-04-16 1962-02-20 Universal Thread Grinding Comp Thread cutting tool with dulled edges on the guide teeth portion
US3093850A (en) * 1959-10-30 1963-06-18 United States Steel Corp Thread chasers having the last tooth free of flank contact rearwardly of the thread crest cut thereby
US3220032A (en) * 1962-04-27 1965-11-30 Balax Inc Thread cutting tap
US3255473A (en) * 1964-01-06 1966-06-14 Joseph J Csiszar Rethreading tool
US3629887A (en) * 1969-12-22 1971-12-28 Pipe Machinery Co The Carbide thread chaser set
US4409868A (en) * 1981-04-13 1983-10-18 The Valeron Corporation Threading tool and method
US20110078897A1 (en) * 2009-10-02 2011-04-07 Christopher John Shahin Stabilizer device for through-hole electrical jacks
US8312621B2 (en) * 2009-10-02 2012-11-20 Christopher John Shahin Stabilizer device for through-hole electrical jacks
US20170028489A1 (en) * 2014-04-08 2017-02-02 Snecma A shaft machining anti-vibration device
US10195680B2 (en) * 2014-04-08 2019-02-05 Safran Aircraft Engines Shaft machining anti-vibration device

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