US3271288A - Electrolytic drilling and tapping apparatus - Google Patents

Electrolytic drilling and tapping apparatus Download PDF

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Publication number
US3271288A
US3271288A US72890A US7289060A US3271288A US 3271288 A US3271288 A US 3271288A US 72890 A US72890 A US 72890A US 7289060 A US7289060 A US 7289060A US 3271288 A US3271288 A US 3271288A
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US
United States
Prior art keywords
cathode
drilling
workpiece
electrolyte
tapping
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
US72890A
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English (en)
Inventor
Joseph H Crawford
William H Peters
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.)
General Electric Co
Original Assignee
General Electric Co
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 General Electric Co filed Critical General Electric Co
Priority to US72890A priority Critical patent/US3271288A/en
Priority to GB42640/61A priority patent/GB938516A/en
Priority to CH1395461A priority patent/CH422188A/de
Priority to FR880460A priority patent/FR1307441A/fr
Application granted granted Critical
Publication of US3271288A publication Critical patent/US3271288A/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
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H9/00—Machining specially adapted for treating particular metal objects or for obtaining special effects or results on metal objects
    • B23H9/003—Making screw-threads or gears

Definitions

  • This invention relates to a method and apparatus for electrolytically drilling and/ or simultaneously tapping holes in conducting materials including very hard metal alloys.
  • one of the objects of this invention is to provide a method and apparatus for the simultaneous drilling and tapping of holes in conducting materials.
  • Another object of the invention is to provide a method and apparatus for electrolytically drilling and tapping holes in very hard metal alloys.
  • a further object is to provide a method for tapping stress-free threads in metals and alloys.
  • FIG. 1 illustrates in schematic form partially sectioned apparatus for electrolytically drilling tapped holes in accordance with this invention
  • FIG. 2 is an enlarged perspective view of the cathode tip of the apparatus illustrated in FIG. 1;
  • FIG. 3 illustrates apparatus for electrolytically drilling tapped holes wherein electrolyte is introduced to the workpiece through the cathode
  • FIG. 4 is an enlarged perspective view of an alternative cathode tip wherein annular threads of increasing thread depth are used to effect the tapping;
  • FIGS. 57 are perspective views of alternative cathode tips for cutting various types of thread.
  • this invention enables the simultaneous drilling and tapping of holes in a workpiece by the passage of electric current through an electrolyte between the apparatus and the workpiece by using an elongated cathode member having a radially extending thread-forming projection at the tip thereof and by moving the cathode along its longitudinal axis and rotating the cathode about this axis in order to bring the rotating cathode to the surface of a workpiece over which electrolyte is flowing.
  • a supporting base is equipped with a threaded aperture with which a feed screw 11 is threadably engaged.
  • the feed screw 11 may be slowly rotated by means of a pulley 12 mounted there on, which is driven by an arrangement consisting of an electric motor 13 and its pulley 14, and a belt 15 or other suitable driving means.
  • electrolyte is constantly introduced to the work surface of the workpiece 21 through a tube 23.
  • the nature of the electrolyte solution is not critical, an example of a satisfactory electrolyte for many applications being ordinary sea water.
  • Power is provided by a D.C. source, as indicated at 24, which is normally at a potential of about 20 volts.
  • the D.C. source is not critical and may vary within a range of 5 to 50 volts, depending on the composition, age, and temperature of the electrolyte as well as the anode-cathode gap.
  • the positive side of the D.C. source is connected to the workpiece 21 and the negative to a bus bar 25 electrically connected to a head portion 26 of the feed screw 11 through a pool of mercury 27 or other conducting media in a cup-shaped hollow of the head portion 26.
  • the apparatus shown in FIG. 3 is similar to that illustrated in FIG. 1 except that the cathode 16 is hollow and the electrolyte is introduced through a swivel connection 23a on the head portion of the feed screw 11.
  • Noncorrosive electrolytes can be used at pressures of the order of 200 p.s.i.g. and the swivel connection allows such pressure to be maintained.
  • the electrical circuit in the embodiment of FIG. 3 is made by means of a brush 29 in contact with a pickup ring 31 around the perimeter of the head portion 26.
  • the tip portion of the cathode of FIG. 3 is equipped with an anode shield 20 which is a floating conducting sleeve overlying the outer insulation layer 17.
  • the anode shield 20 neutralizes any charged flow passing over the cathode that otherwise might cause uncontrolled metal removal from the threads already cut.
  • the extending tip end of the cathode 16 is shown with the thread-forming member in the form of an annular projection in which the radial depth increases as the distance from the tip increases.
  • This construction is particularly advantageous for deep-cut threads as the thread cutting continues around the entire perimeter of the cathode 16 as it is being advanced into the workpiece.
  • FIGS. 58 illustrate cathode tips having alternative shapes of projections 18 for cutting Wittworth, square, and acme threads. Obviously, eccentric thread contours are easily obtainable by means of the present invention.
  • the drilling rate can be increased by leaving a central core in place. This core can be removed to provide a rod of hard metal which can be threaded by providing the cathode with an internal threadcutting projection during the metal-removal operation.
  • the aforementioned Crawford and Halverstadt appli cation described the drilling of holes in highly refractory alloys at rates as high as sixteen inches per hour at current densities of the order of 10,000 amps. per square inch. Similar feed rates and current densities can be maintained in the present invention and long, thin tapped holes can be produced by a simultaneous drilling and tapping operation. The tap threads are not worn by this operation since they do not come into contact with the workpiece.
  • an elongated cathode having a radially extending threadforming projection at a tip end thereof, a layer of insulation over the portions of said cathode exposed to electrolyte except for the tip surface and thread-forming projection, a conducting sleeve overlying said layer of insulation, means for moving said cathode along its longitudinal axis and rotating said cathode around said axis, and means for introducing electrolyte to the tip portion of said cathode.

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  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
US72890A 1960-12-01 1960-12-01 Electrolytic drilling and tapping apparatus Expired - Lifetime US3271288A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US72890A US3271288A (en) 1960-12-01 1960-12-01 Electrolytic drilling and tapping apparatus
GB42640/61A GB938516A (en) 1960-12-01 1961-11-29 Improvements in electrolytic tapping method and apparatus
CH1395461A CH422188A (de) 1960-12-01 1961-11-30 Verfahren und Einrichtung zur Herstellung eines Gewindes oder einer Bohrung und eines Gewindes mittels elektrolytischer Materialabtragung
FR880460A FR1307441A (fr) 1960-12-01 1961-11-30 Procédé et appareil électrolytiques pour tarauder une pièce électroconductrice

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US72890A US3271288A (en) 1960-12-01 1960-12-01 Electrolytic drilling and tapping apparatus

Publications (1)

Publication Number Publication Date
US3271288A true US3271288A (en) 1966-09-06

Family

ID=22110362

Family Applications (1)

Application Number Title Priority Date Filing Date
US72890A Expired - Lifetime US3271288A (en) 1960-12-01 1960-12-01 Electrolytic drilling and tapping apparatus

Country Status (3)

Country Link
US (1) US3271288A (de)
CH (1) CH422188A (de)
GB (1) GB938516A (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4144936A (en) * 1977-06-16 1979-03-20 Smith International, Inc. Down hole milling or grinding system
US6264822B1 (en) * 1998-11-05 2001-07-24 General Electric Company Method for electrochemical machining
CN106808038A (zh) * 2015-12-02 2017-06-09 财团法人金属工业研究发展中心 电化学加工装置及加工方法
CN108714722A (zh) * 2018-04-28 2018-10-30 南京航空航天大学 齿高渐变电解铣削系统及其加工大型钛合金工件外圆方法
CN109551066A (zh) * 2018-11-20 2019-04-02 广东轻工职业技术学院 一种空间螺旋孔电火花加工装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3336213A (en) * 1963-06-19 1967-08-15 Gen Electric Cathode for electrolytic machining

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB335003A (en) * 1929-07-24 1930-09-18 Wladimir Gusseff Method and apparatus for the electrolytic treatment of metals
US2526423A (en) * 1947-04-10 1950-10-17 Rudorff Dagobert William Apparatus and method for cutting materials
GB661273A (en) * 1948-03-17 1951-11-21 Monochrome Ltd Improvements in and relating to the electrolytic treatment of metallic surfaces
US2650979A (en) * 1950-06-21 1953-09-01 Method X Company Method and apparatus for electrically disintegrating metallic material
US2739935A (en) * 1952-09-30 1956-03-27 George L Kehl Electrolytic cutting of metals
US2773968A (en) * 1956-01-10 1956-12-11 Cincinnati Milling Machine Co Electro discharge machine
GB789293A (en) * 1952-11-14 1958-01-15 Sparcatron Ltd Improvements in and relating to methods and means for removal of material from solid bodies
US2902584A (en) * 1955-12-30 1959-09-01 Agie Ag Ind Elektronik Method of detaching material by electric erosion
FR1241349A (fr) * 1958-11-10 1960-09-16 Anocut Eng Co Procédé et appareil pour façonner des pièces
US2982842A (en) * 1957-03-21 1961-05-02 Tuscher Jean Edouard Method for automatically executing cutters and the like shaped parts of revolution through electric erosion
US3051638A (en) * 1959-03-12 1962-08-28 United States Steel Corp Method and apparatus for making a tapered thread
US3120482A (en) * 1959-11-16 1964-02-04 Anocut Eng Co Apparatus for electrolytic hole sinking

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB335003A (en) * 1929-07-24 1930-09-18 Wladimir Gusseff Method and apparatus for the electrolytic treatment of metals
US2526423A (en) * 1947-04-10 1950-10-17 Rudorff Dagobert William Apparatus and method for cutting materials
GB661273A (en) * 1948-03-17 1951-11-21 Monochrome Ltd Improvements in and relating to the electrolytic treatment of metallic surfaces
US2650979A (en) * 1950-06-21 1953-09-01 Method X Company Method and apparatus for electrically disintegrating metallic material
US2739935A (en) * 1952-09-30 1956-03-27 George L Kehl Electrolytic cutting of metals
GB789293A (en) * 1952-11-14 1958-01-15 Sparcatron Ltd Improvements in and relating to methods and means for removal of material from solid bodies
US2902584A (en) * 1955-12-30 1959-09-01 Agie Ag Ind Elektronik Method of detaching material by electric erosion
US2773968A (en) * 1956-01-10 1956-12-11 Cincinnati Milling Machine Co Electro discharge machine
US2982842A (en) * 1957-03-21 1961-05-02 Tuscher Jean Edouard Method for automatically executing cutters and the like shaped parts of revolution through electric erosion
FR1241349A (fr) * 1958-11-10 1960-09-16 Anocut Eng Co Procédé et appareil pour façonner des pièces
US3051638A (en) * 1959-03-12 1962-08-28 United States Steel Corp Method and apparatus for making a tapered thread
US3120482A (en) * 1959-11-16 1964-02-04 Anocut Eng Co Apparatus for electrolytic hole sinking

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4144936A (en) * 1977-06-16 1979-03-20 Smith International, Inc. Down hole milling or grinding system
US6264822B1 (en) * 1998-11-05 2001-07-24 General Electric Company Method for electrochemical machining
CN106808038A (zh) * 2015-12-02 2017-06-09 财团法人金属工业研究发展中心 电化学加工装置及加工方法
CN108714722A (zh) * 2018-04-28 2018-10-30 南京航空航天大学 齿高渐变电解铣削系统及其加工大型钛合金工件外圆方法
CN109551066A (zh) * 2018-11-20 2019-04-02 广东轻工职业技术学院 一种空间螺旋孔电火花加工装置
CN109551066B (zh) * 2018-11-20 2020-09-11 广东轻工职业技术学院 一种空间螺旋孔电火花加工装置

Also Published As

Publication number Publication date
CH422188A (de) 1966-10-15
GB938516A (en) 1963-10-02

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