US3604305A - Recessed screw - Google Patents

Recessed screw Download PDF

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Publication number
US3604305A
US3604305A US835518A US3604305DA US3604305A US 3604305 A US3604305 A US 3604305A US 835518 A US835518 A US 835518A US 3604305D A US3604305D A US 3604305DA US 3604305 A US3604305 A US 3604305A
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US
United States
Prior art keywords
recess
square
corners
fastener
angle
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
US835518A
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English (en)
Inventor
Geoffrey Dreger
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.)
PL Robertson Manufacturing Co Ltd
Original Assignee
PL Robertson Manufacturing Co Ltd
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 PL Robertson Manufacturing Co Ltd filed Critical PL Robertson Manufacturing Co Ltd
Application granted granted Critical
Publication of US3604305A publication Critical patent/US3604305A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B23/00—Specially shaped nuts or heads of bolts or screws for rotations by a tool
    • F16B23/0007—Specially shaped nuts or heads of bolts or screws for rotations by a tool characterised by the shape of the recess or the protrusion engaging the tool
    • F16B23/003—Specially shaped nuts or heads of bolts or screws for rotations by a tool characterised by the shape of the recess or the protrusion engaging the tool star-shaped or multi-lobular, e.g. Torx-type, twelve-point star
    • 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
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S411/00—Expanded, threaded, driven, headed, tool-deformed, or locked-threaded fastener
    • Y10S411/919—Screw having driving contacts

Definitions

  • This invention relates to improvements in screws or the like and more particularly to an improved recess formation for screws or similar fasteners.
  • RELATED INVENTIONS Related inventions comprise a punch to produce the improved recess formation of this invention and a driver bit for driving screws provided with the improved recess formation of this invention.
  • the advantageous driving characteristics of the square recess screw stem from the fact that the corners of the square are defined between right angularly meeting wall portions of appreciable depth which are substantially vertical and there are no fine sections in the recess formation to fracture or ream out and no fine sections in either the punch or driver bit to break off.
  • the mating driver bit which is of corresponding square cross section imparts torque positively to the screw through such right angularly disposed essentially vertical recess wall portions, the torque being transferred essentially at or adjacent to the corners of the recess although the additional wall area is, of course, available to resist reaming.
  • the essentially vertical walls preclude any appreciable upward camming force tending to eject the driver so that full torque transfer is effected without requiring any excessive or even appreciable downward pressure on the driver thus reducing operator fatigue while essentially eliminating tool slippage.
  • this verticality of the walls provides a clinging action between the surfaces of the recess and opposite sides of the driver bit which enables the screw to be placed on and carried firmly by the driver bit to the point of application.
  • the square configuration of the socket also involves the concentration of wear on the forming punch at a limited number of critical points particularly at the four corners of the recess so that while punch life is acceptable it would be highly advantageous to enable punch life to be extended.
  • Another important object is to provide a recessed screw which will not only accept the present square recess bit in proper driving fit but will accept such bit while moving at high speed as the driving gun is continued to be operated in moving from screw to screw where for example, a series of screws are preoriented for driving in rapid succession.
  • the improved recess formation comprises a symmetrical readily formed recess having eight corners or points disposed in 45 angularly spaced relation around the recess and defined by right angularly disposed downwardly extending adjoining recess wall portions, the recess presenting two sets of four alternate corners defined by eight recess wall portions with each such set of comers and wall portions outlining a square whereby the recess is adapted to receive a square-driving bit in two 45 angularly displaced positions of fit.
  • FIG. 1 is a broken away elevational view of a punch for forming a recess according to the invention in a flat head screw.
  • FIG. 2 is a mid vertical sectional view of the head of a screw in which the recess formation of the invention has been punched by the punch of FIG. 1.
  • FIG. 3 is a top plan view of the screw of FIG. 1.
  • FIG, 4 is a view similar to FIG. 1 but showing a punch for forming a recess according to the invention and for the same time providing a heading operation to produce a roundheaded screw.
  • FIG. 5 is a midvertical sectional view of the head-of a screw produced by the punch of FIG. 4.
  • FIG. 6 is a top plan view of the screw of FIG. 5.
  • FIG. 7 is an enlarged schematic view showing the outline in top plan view of the recess formation according to the invention and illustrating in horizontal section one position of fit for a square driver bit received in the recess and in dotted line the alternative 45 displaced position of driver bit fit.
  • FIG. 8 is an enlarged part plan, part diagrammatic view comparing the displacement of the metal of the screwhead to provide a recess according in the present invention and the displacement of the metal of a screwhead to provide a square recess.
  • FIG. 9 is an enlarged part vertical sectional view of a screwhead embodying a recess according to the invention.
  • the recess formation of the present invention is formed to present eight symmetrically disposed points or comers 1 each defined by right angularly disposed adjoining wall portions 2 and 3 which define an internal angle x of 90 at each of the corners.
  • the points or corners 1 starting from the top and moving clockwise are designated ia, 1b 1c, 1d, 1e, 1f, lg and lit and the defining wall portions are designated 21: 3a, 2b 3b, 20 3c, 2d 3d, 223e, 2f 3f, 2g 3g, 2h 3h.
  • corners la, 1c, 1e, and 13 in conjunction with wall portions 2a 3a, 2c 30, 2e 3 e, and 2g 3g define one square adapted to receive a square-driving bit or tool 4.
  • the alternative sequence of corners and wall portions lb, 1d, 1 f and lb and 2b 3b, 2d 3d, 2 ⁇ " 3f and 2k 311 also define a square and similarly are adapted to receive the square bit 4.
  • Adjoining wall portions such as 2a and 3h meet to define an included angle y of 135 and an internal angle of 225.
  • the wall portions 2 and 3 all of which are identical in shape and area preferably deviate slightly from the vertical and incline inwardly at an angle of from 3 to 3 towards the bottom wall 5 of the recess which preferably is of conical form having an angle from 50 to 56 to the horizontal.
  • the entrance 6 to the recess is also preferably bevelled at an angle of 45.
  • the juncture of the conical bottom wall 5 and the sidewalls 2 and 3 are defined by arcuate juncture lines 7 and 28.
  • This preferred recess construction with the above taper and the appropriate depth and conical bottom wall are selected to conform the recess to receive in accurate fit the existing drivers now employed with recesses of the square configuration of U.S. Pat. No. 2,914,984 in either of the two positions illustrated in FIG. 7 so that the screw may be driven by existing drivers.
  • the eight pointed or eight cornered recess of the present invention provides an increased area of entrance to the screw over the present square recess socket.
  • the inner circle 8 represents the area available for entrance of the driving bit 4 into a square recess.
  • the second inner circle 9 represents the area available for entrance of the bit 4 into the recess of the present invention.
  • the area between the two circles 8 and 9 represents increased area for entrance, i.e., the increased ease of entrance.
  • a square recess involves the displacement out of circular form of four times the mass of metal lying between the inner circle 8 and the outer circle between say corner la and corner 1c and represented by the shaded areas l2, l3, 14.
  • the amount of metal displaced out of circular form is represented only by four times the shaded areas 12 and 14 and all of this mass lies between the second inner circle 9 and the outer circle 10.
  • a highly important advantage flowing from the precisely circular configuration of the head is the uniformity of stress distribution in the head essentially eliminating weakened or crystallized areas which might fracture under high torque stress. Because of the uniformity of the stressing it has been found that a socket formation according to the present invention can readily be formed in stainless steel or other hard to work with metals without splitting, fracturing or weakening the screwhead.
  • the recess of the present invention is formed for example by the punch 15 of FIG. 1 which is used to produce the flat head screw 16 of FIG. 2.
  • One of the critical points of wear in a punch occurs at a corner such as the corners I7 which form the points or corners l of the recess. This wear is particularly concentrated at the juncture points 18 with the bottom wall formation 19.
  • the impact blow of the punch is absorbed at only four corners and when these corners wear the recess will not be sufficiently accurate to allow the driving bit to seat firmly and properly in the recess.
  • This problem is compounded when the sidewalls of the recess are tapered because of the mismatch of the driver bit taper with the recess taper if the bit cannot seat fully home.
  • FIG. 4 illustrates a modified form of punch 20 used to produce the screw 21.
  • This punch includes a recessed block 22 having a recess 23 which is adapted to shape the rounded head 24 of the screw at the same time that it forms the screw recess.
  • the recess forming portion 25 of the punch is identical with the punch 15.
  • screws provided with a recess formation according to the invention may be hardened, plated, or otherwise treated with the same facility as present square recess screws.
  • a threaded fastener having a shank and an enlarged head meeting at a first line of juncture, and enclosing a substantially circular area centered on the longitudinal axis of the fastener, said head having a tool-engaging socket extending into its upper end, said socket being centered on and symmetrical relative to the longitudinal axis of the fastener and presenting in plan eight symmetrically disposed comers, each corner being defined by a pair of identical downwardly extending sidewall portions which intersect at a right angle, any series of four alternate corners and their defining sidewall portions outlining a square, the remaining series of four alternate corners and their defining sidewall portions outlining a second square in 45 angular relation to said first-mentioned square, each sidewall portion defining a part of an included angle of 135 with a sidewall portion defining a part of the next adjacent comer along an intersection equally spaced from such corners to provide a total of 16 identical sidewall portions, each of said sidewall portions being inclined inwardly significantly

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Food-Manufacturing Devices (AREA)
  • Forging (AREA)
  • Connection Of Plates (AREA)
US835518A 1969-06-23 1969-06-23 Recessed screw Expired - Lifetime US3604305A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US83551869A 1969-06-23 1969-06-23
CA55523 1969-06-27

Publications (1)

Publication Number Publication Date
US3604305A true US3604305A (en) 1971-09-14

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ID=25666106

Family Applications (1)

Application Number Title Priority Date Filing Date
US835518A Expired - Lifetime US3604305A (en) 1969-06-23 1969-06-23 Recessed screw

Country Status (6)

Country Link
US (1) US3604305A (fr)
BE (1) BE752228A (fr)
CA (1) CA898016A (fr)
DE (1) DE2031024A1 (fr)
FR (1) FR2052847A5 (fr)
GB (1) GB1294765A (fr)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4151621A (en) * 1974-09-12 1979-05-01 Phillips Screw Company Tools for punching fastener heads
US4384812A (en) * 1979-04-03 1983-05-24 Miyagawa Kinzoku Kogyo Company Limited Screw and screw forming tool
US4712586A (en) * 1985-05-10 1987-12-15 Mcgard, Inc. Pipe plug and centering construction for centering ridged key in mating groove in pipe plug
EP0488541A1 (fr) * 1990-11-26 1992-06-03 Yugenkaisha Shinjo Seisakusho Vis à empreinte et embout de tournevis pour celle-ci
US5366330A (en) * 1993-07-26 1994-11-22 Vsi Corporation Fastener head with internal recess having a radial slot configuration and installation tool therefor
US5641258A (en) * 1994-04-14 1997-06-24 Sala; Carlo Recessed screw head
EP1035336A3 (fr) * 1999-03-08 2002-04-03 JJCT Enterprises, Inc. Outil de fixation, dispositif de fixation et outil de formage
US6848907B2 (en) * 2002-06-24 2005-02-01 Osstem Implant Co., Ltd. Screw for dental implants
US20050135898A1 (en) * 2003-03-10 2005-06-23 Jory Bell Screw and screw driver
US20060110237A1 (en) * 2004-11-23 2006-05-25 Richard Belinda Spline drive fastener system
CN103185055A (zh) * 2011-12-29 2013-07-03 鸿富锦精密工业（深圳）有限公司 紧固件、与其配合的驱动件及成型该紧固件的冲子
CN103599985A (zh) * 2013-11-14 2014-02-26 桂林福达全州高强度螺栓有限公司 螺栓加工过程中棒料倒角冲孔的装置
CN104384306A (zh) * 2014-11-25 2015-03-04 河南航天精工制造有限公司 一种反冲方模具
US20160115988A1 (en) * 2013-06-05 2016-04-28 Ejot Gmbh & Co. Kg Screw with a screw head which has a drive
US20160361947A1 (en) * 2015-06-12 2016-12-15 Hyundai Motor Company Antitheft nut
USD812460S1 (en) * 2016-08-19 2018-03-13 Katsuyuki Totsu Screw
US11071574B2 (en) 2012-12-17 2021-07-27 Depuy Ireland Unlimited Company Twist-drivable pin assembly
CN114396422A (zh) * 2022-01-28 2022-04-26 航天精工股份有限公司 一种加强型十二角头螺栓及加工方法
US11572914B2 (en) * 2020-02-27 2023-02-07 Essence Method Refine Co., Ltd. Screw having a head with different sockets

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3337535A1 (de) * 1983-10-14 1985-05-02 Alfons 5758 Fröndenberg Knoche Schraube mit verbesserten innenantrieb, praegestempel zum pressen des innenantriebs einer derartigen schraube und schraubendreher fuer diese schraube
IT8452845V0 (it) * 1984-01-17 1984-01-17 Fossati Onorina Vite adatta a coppie di serraggio di precisione

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH250449A (de) * 1945-09-18 1947-08-31 Schiatti Emilio Ein Gewinde aufweisendes Verbindungsorgan.
US2914984A (en) * 1956-09-20 1959-12-01 Robertson Mfg Co Screw socket of pyramidal cross section terminating in a conical bottom wall

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH250449A (de) * 1945-09-18 1947-08-31 Schiatti Emilio Ein Gewinde aufweisendes Verbindungsorgan.
US2914984A (en) * 1956-09-20 1959-12-01 Robertson Mfg Co Screw socket of pyramidal cross section terminating in a conical bottom wall

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4151621A (en) * 1974-09-12 1979-05-01 Phillips Screw Company Tools for punching fastener heads
US4384812A (en) * 1979-04-03 1983-05-24 Miyagawa Kinzoku Kogyo Company Limited Screw and screw forming tool
US4712586A (en) * 1985-05-10 1987-12-15 Mcgard, Inc. Pipe plug and centering construction for centering ridged key in mating groove in pipe plug
EP0488541A1 (fr) * 1990-11-26 1992-06-03 Yugenkaisha Shinjo Seisakusho Vis à empreinte et embout de tournevis pour celle-ci
US5219253A (en) * 1990-11-26 1993-06-15 Yugenkaisha Shinjo Seisakusho Recessed screw and a driver bit engageable therewith
US5366330A (en) * 1993-07-26 1994-11-22 Vsi Corporation Fastener head with internal recess having a radial slot configuration and installation tool therefor
US5641258A (en) * 1994-04-14 1997-06-24 Sala; Carlo Recessed screw head
EP1035336A3 (fr) * 1999-03-08 2002-04-03 JJCT Enterprises, Inc. Outil de fixation, dispositif de fixation et outil de formage
US6575061B2 (en) 1999-03-08 2003-06-10 John B. Wagner Driver, fastener and forming tool
US6848907B2 (en) * 2002-06-24 2005-02-01 Osstem Implant Co., Ltd. Screw for dental implants
US20050135898A1 (en) * 2003-03-10 2005-06-23 Jory Bell Screw and screw driver
US20060110237A1 (en) * 2004-11-23 2006-05-25 Richard Belinda Spline drive fastener system
CN103185055A (zh) * 2011-12-29 2013-07-03 鸿富锦精密工业（深圳）有限公司 紧固件、与其配合的驱动件及成型该紧固件的冲子
US11071574B2 (en) 2012-12-17 2021-07-27 Depuy Ireland Unlimited Company Twist-drivable pin assembly
US20160115988A1 (en) * 2013-06-05 2016-04-28 Ejot Gmbh & Co. Kg Screw with a screw head which has a drive
US9702392B2 (en) * 2013-06-05 2017-07-11 Ejot Gmbh & Co., Kg Screw with a screw head which has a drive
CN103599985A (zh) * 2013-11-14 2014-02-26 桂林福达全州高强度螺栓有限公司 螺栓加工过程中棒料倒角冲孔的装置
CN104384306A (zh) * 2014-11-25 2015-03-04 河南航天精工制造有限公司 一种反冲方模具
US20160361947A1 (en) * 2015-06-12 2016-12-15 Hyundai Motor Company Antitheft nut
US9815324B2 (en) * 2015-06-12 2017-11-14 Hyundai Motor Company Antitheft nut
USD812460S1 (en) * 2016-08-19 2018-03-13 Katsuyuki Totsu Screw
US11572914B2 (en) * 2020-02-27 2023-02-07 Essence Method Refine Co., Ltd. Screw having a head with different sockets
CN114396422A (zh) * 2022-01-28 2022-04-26 航天精工股份有限公司 一种加强型十二角头螺栓及加工方法

Also Published As

Publication number Publication date
GB1294765A (en) 1972-11-01
CA898016A (en) 1972-04-18
BE752228A (fr) 1970-12-21
FR2052847A5 (fr) 1971-04-09
DE2031024A1 (de) 1971-01-21

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