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US2033557A - Tap - Google Patents

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Publication number
US2033557A
US2033557A US708847A US70884734A US2033557A US 2033557 A US2033557 A US 2033557A US 708847 A US708847 A US 708847A US 70884734 A US70884734 A US 70884734A US 2033557 A US2033557 A US 2033557A
Authority
US
United States
Prior art keywords
tap
flute
threads
cut
edge
Prior art date
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
US708847A
Other languages
English (en)
Inventor
Jesse D Tucker
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.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US708847A priority Critical patent/US2033557A/en
Priority to FR805360D priority patent/FR805360A/fr
Application granted granted Critical
Publication of US2033557A publication Critical patent/US2033557A/en
Priority to GB7897/36A priority patent/GB459689A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • B23G5/00—Thread-cutting tools; Die-heads
    • B23G5/02—Thread-cutting tools; Die-heads without means for adjustment
    • B23G5/06—Taps
    • 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
    • Y10T408/9048—Extending outwardly from tool-axis

Definitions

  • This invention relates to thread cutting taps of the general type shown in ,my Patent No.
  • A. further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for which it is designed.
  • Figure 1 is a longitudinal elevation of the tap.
  • Figure 2 is a similar view partly in section taken on the line 2-2 of Figure 1.
  • Figure 3 is an enlarged cross section on the of Figure l.
  • 4 is a similar view on the line 4-4 of 5 is a fragmentary enlarged longitudinal section of the tip end of a tap,.showing a modified cutting of the endmost threads.
  • the tap comprises a body l squared at one end as at 2 as .usual for engagement with a holding chuck.
  • the body from its outer end to a point short of the end 2 is provided with longitudinal flutes 3 forming a rib 4 .therebetween; the circumferential .extent of the continuous ungrooved portion of the body being preferably somewhat greater than 180 or approximating three-fifths of the circumference.
  • the bottoms of the grooves preferably slope below the edges .of the said unbroken portion relative to a straight line permited thereacross, so as to insure the sharpness of said edges.
  • This unbroken body portion is formed with threads 5, the body at its outer end being provided with a reducing taper as at 6 to reduce the depth of the adjacent threads as is customary.
  • I provide another flute l intermediate the flutes 3.
  • This flute 1 extends from the outer end of the body and for approximately onehalf the length of the threaded portion thereof; terminating at the outer periphery of the rib 4.
  • Said flute 1 is formed with a longitudinal concave curvature and increases in width toward the outer end of the body; and is also of increasingly concave curvature transversely in the direction of the outer end of the tap.
  • 10 said flute 1 extends across the end portions of the groove 3 and cuts away and obliterates the corresponding portion of the rib 4.
  • This cutting away of the rib with the curvature and of the general form above mentioned provides a flute of gradually increasing width toward the outer end of the tap and forms a shallow trough 8 at said end, the. bottom of which is below the plane of the bottom of the grooves 3.
  • Said outer end of the tap is therefore of crescent shaped form as clearly indicated in Figure 2.
  • the transverse cut of the flute l is so offset or tilted relative to the plane in which the opposed edges of the threads lie, that it makes a sharp angle with the periphery of the tap at the leading edge L of the same, while terminating inwardly of said periphery at the trailing edge; and said leading edge L is made lower than the trailing edge as shown in Figure 3.
  • This provides a very free cutting lip for initial engagement with the hole to be tapped, a feature which is enhanced by the fact that the adjacent longitudinal edge of the threaded portion at the lip on the leading side assumes a slope as indi cated at 9 on account of the intersection of the cut of the flute l with said longitudinal edge. Also of course this edge 9 of the lip is actually a short portion of a spiral of long pitch, due to the angular intersection of the cancave flute with the cylindrical body of the tap.
  • This offsetting of the flute out also allows the groove 3 on the trailing side of the tap to extend undisturbed to the end of the tap, as shown in Figure 1.
  • the edges of the threads at the lip are therefore relatively blunt in the transverse plane of the tap, as indicated at M. This prevents said threads at the trailing edge and which are used as a steady rest, from possibly chipping .oif when under a heavy cut.
  • the free cutting lip forms in effect a chisel edge making turning of the tap into the metal very easy.
  • the shavings out by the top threads and entering the main flute space are definitely directed down or toward the bottom of the hole by reason of the slope of the bottom of the flute I, while the size of the flute space due to its hollow ground form provides adequate room for the collection of the shavings as the tap approaches the bottom of the hole (if the latter is blind) without danger of choking the hole.
  • the other flutes 3, apart from forming sharp edges of the ends of the threads, only serve to scrape up any fine shavings which might otherwise work under the thread.
  • the tap therefore runs twice as easy as do ordinary taps, besides having far greater strength owing to the use of the one rib 4.
  • the point of the tap does all-the actual cutting and its form renders it very easy to sharpen in case it becomes dull.
  • Atap comprising a body, threads cut in the body from one end and extending continuously thereabout for at least 180 of the circumference of the body, and a flute cut lengthwise in the body and disposed substantially central of that portion of the body lying between the threads and having a converging slope to said end of the body to reduce the cross sectional area of the body at said end to a size less than one-half the circumferential area of the body, said flute having a transverse concave curvature and flaring laterally toward said end of the tap to intersect the terminations of the threads only on the leading side of the tap.
  • a tap comprising a body, threads cut in the body from one end and extending continuously thereabout for at least 180 of the circumference of the body for the major portion of such extent, and a flute cut lengthwise in the body and disposed substantially central of that portion of the body lying between the threads and having a converging slope to said end of the body to reduce the cross sectional area of the body at that end to a size less than one half the circumferential area of the body; said flute having a transverse concave curvature and flaring laterally toward the outer end of the tap to meet the opposed terminations of the threads at said end, and said flute being canted transversely and relative to the transverse plane in which the opposed terminations of the threads lie so that the bottom of the flute at said end of the tap forms a sharper angle with the adjacent periphery of the tap at the leading end of the threads than at the following end thereof.
  • a tap comprising a body, threads cut in the body from one end and extending continuously thereabout for at least 180 of the circumference of the body, a pair of spaced flutes cut lengthwise in the body along the opposed terminations of the threads and forming a radial rib between said flutes, and a third flute cut substantially central of said first named flutes and extending from said end of the tap and the adjacent opposed terminations of the threads in longitudinally diverging relation to the axis of the tap toward the opposite end of the same to merge along its edge portions into the first named flutes and eliminating the endmost portion of the rib.
  • a tap comprising a body, threads cut in the body from one end and extending continuously thereabout for at least 180 of the circumference of the body, and a flute formed in the body and extending lengthwise thereof from said end; said flute at its outer end projecting below the transverse plane of the opposed terminations of the adjacent threads and arranged to meet the leading thread terminations at an acute angle, but leaving the opposed thread terminations blunt.
  • a tap comprising a body, threads cut in the body from one end and extending continuously thereabout for at least 180 of the circumference of the body, and a flute formed in the body and extending lengthwise thereof from said end; said flute at its outer end projecting below the transverse plane of the opposed terminations of the adjacent threads, said flute being cut so that it intersects the leading thread terminations at and for some distance from said end of the tap, to form a substantially wedgeshaped cutting lip; the out of the flute on the opposite side terminating inwardly of the corresponding thread terminations to leave the same relatively blunt edged.
  • a hole-working tool comprising a cylindrical body and a concave flute extending lengthwise of the body from one end thereof and arranged at said end to reduce the cross sectional area thereof to a size less than one half the circumferential area of the body and merging into the circumferential surface of the body at acute angles therewith to form leading and following edges; the flute at said end of the body being formed with a lateral flare in the direction of the leading edge so as to intersect the normal line of said edge for a predetermined distance from and to said end of the body and to provide a cutting lip whose edge is relatively sharp compared to the opposed following edge.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Food-Manufacturing Devices (AREA)
US708847A 1934-01-29 1934-01-29 Tap Expired - Lifetime US2033557A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US708847A US2033557A (en) 1934-01-29 1934-01-29 Tap
FR805360D FR805360A (fr) 1934-01-29 1936-02-24 Taraud
GB7897/36A GB459689A (en) 1934-01-29 1936-03-16 Improvements in and relating to screw-cutting taps

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US708847A US2033557A (en) 1934-01-29 1934-01-29 Tap

Publications (1)

Publication Number Publication Date
US2033557A true US2033557A (en) 1936-03-10

Family

ID=9841903

Family Applications (1)

Application Number Title Priority Date Filing Date
US708847A Expired - Lifetime US2033557A (en) 1934-01-29 1934-01-29 Tap

Country Status (3)

Country Link
US (1) US2033557A (fr)
FR (1) FR805360A (fr)
GB (1) GB459689A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4316683A (en) * 1979-08-24 1982-02-23 Roger A. Schott Semi-circular thread tap
JP2013043265A (ja) * 2011-08-26 2013-03-04 Hitachi Industrial Equipment Systems Co Ltd 管用テーパタップ
US20150016911A1 (en) * 2012-03-09 2015-01-15 Osg Corporation Spiral tap
JP6420515B1 (ja) * 2018-05-18 2018-11-07 株式会社三秀 タップ

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3458882A (en) * 1967-03-27 1969-08-05 Gerald W Kelly Thread-cutting device
FR2542653B1 (fr) * 1983-03-14 1987-02-20 Gavelle Dominique Taraud a goujure convexe

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4316683A (en) * 1979-08-24 1982-02-23 Roger A. Schott Semi-circular thread tap
JP2013043265A (ja) * 2011-08-26 2013-03-04 Hitachi Industrial Equipment Systems Co Ltd 管用テーパタップ
US20150016911A1 (en) * 2012-03-09 2015-01-15 Osg Corporation Spiral tap
JP6420515B1 (ja) * 2018-05-18 2018-11-07 株式会社三秀 タップ
JP2019198942A (ja) * 2018-05-18 2019-11-21 株式会社三秀 タップ

Also Published As

Publication number Publication date
GB459689A (en) 1937-01-13
FR805360A (fr) 1936-11-18

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