US3234982A - Driver for recessed head fasteners - Google Patents

Driver for recessed head fasteners Download PDF

Info

Publication number
US3234982A
US3234982A US289996A US28999663A US3234982A US 3234982 A US3234982 A US 3234982A US 289996 A US289996 A US 289996A US 28999663 A US28999663 A US 28999663A US 3234982 A US3234982 A US 3234982A
Authority
US
United States
Prior art keywords
driving
wings
tip
bit
recess
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
US289996A
Other languages
English (en)
Inventor
Jr George B Stillwagon
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.)
Gardner Denver Inc
Original Assignee
Gardner Denver Inc
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 Gardner Denver Inc filed Critical Gardner Denver Inc
Priority to US289996A priority Critical patent/US3234982A/en
Priority to DE19641478789 priority patent/DE1478789A1/de
Priority to GB25982/64A priority patent/GB1074206A/en
Application granted granted Critical
Publication of US3234982A publication Critical patent/US3234982A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B15/00—Screwdrivers
    • B25B15/001—Screwdrivers characterised by material or shape of the tool bit
    • B25B15/004—Screwdrivers characterised by material or shape of the tool bit characterised by cross-section
    • B25B15/005—Screwdrivers characterised by material or shape of the tool bit characterised by cross-section with cross- or star-shaped cross-section

Definitions

  • Recessed head threaded fastener devices have become generally used throughout the industry in manufacturing and assembling operations since they are readily adapted for use with power driving devices.
  • the bits used with such power driving devices often break long before they are worn out. Such breakage may occur at one of the driving wings of the tool or it may occur completely across the lower or small end of the tool. It has been found that such breakage is the result of either concentration of the driving load at any one or two of the driving wings, or a concentration of torque at the tip of the bit rather than further up on the wings.
  • the tip of the bit is the point which is most vulnerable to breaking and, at the same time, has the poorest driving efiiciency in that it provides the least amount of driving leverage and s tear strength.
  • One of the important objects and advantages of this invention is the provision of a tool for driving recessed threaded fasteners which is configured so that the driving contact of the wings is concentrated at an area of highest strength of the bit, which is also the area of greatest mechanical advantage.
  • a further advantage which accrues is that the driving force is applied to the threaded fastener head at a region of its greatest strength.
  • the above object and advantages of this invention are achieved by suitably forming, such as by milling, coining, or relieving, the driving wings so that driving contact between the wings and the adjacent driven surface of the recess is limited to a region adjacent the top or the outer surface of the screw recess.
  • the invention provides a bit which has wings configured such that the major portion of the torque is applied to the screw recess by the portion of the driving wings nearest the top opening of the recess. In this manner, the invention assures that none of the driving torque is applied to the threaded fasteners through the tip of the bit or through the portion of the wings nearest the tip, when properly entered in the recess.
  • a further object of this invention is to provide a more eflicient driving tool for cruciform-slotted fasteners.
  • a still further object of this invention is to provide a driver having relieved wings which provides easy entry into the slot and which assures that the driving torque is transmitted through the Wings adjacent the top of the screw recess.
  • a further object of the invention is to provide an improved driving bit of the character described for use with screw slots having a negative lead angle on the driving side and which does not materially increase the cam out between the driver and the driven elements.
  • FIG. 1 is an elevation of a driver constructed according to this invention shown as being received in the head of a typical threaded fastener shown in section;
  • FIG. 2 is a horizontal section through the driver and fastener taken generally along the line 2-2 of FIG. 1 showing the driving contact between the wings and the driven recess surfaces;
  • FIG. 3 is a further horizontal section taken generally along the line 3-3 of FIG. 1 showing the relief of the driving wings and the absence of driving contact;
  • FIG. 4 is a section similar to that of FIG. 3- but taken further down in the recess toward the tip of the driver generally along the line 4-4 of FIG. 1;
  • FIG. 5 is an enlarged fragmentary elevational view of one of the driving wings of the driver of FIG. 1;
  • FIG. 6 shows a modified form of the wing of FIG. 5
  • FIG. 7 is an elevational view of a modified form of the invention particularly adapted for use with screw recesses having a positive lead angle or undercut formed in the driven surface of the slot;
  • FIG. 8 is a partially broken away elcvational view of the head of a threaded fastener having such an undercut
  • FIG. 9 is a partially broken away elevational view showing the driver tool of FIG. 7 inserted in the socket of FIG. 8;
  • FIG. 10 is a transverse section taken generally along the line 1010 of FIG. 9;
  • FIG. 11 is an enlarged elevational view of one of the driving wings of the embodiment of FIGS. 7-10.
  • the bit 20 may have an upper end adapted for attachment to a driving handle, but is preferably formed in such a manner as to be received within a suitable chuck or bit holder on a power tool.
  • the material of the body of the tool 20 may be constructed from stock material such as from a length of hexagonal bar stock which has had the driving end tapered toward a point. While cylindrical stock may be used, 'the hexagonal or other flat-sided stock material is preferred since it provides a secure mounting for use with power tools and the like.
  • the driving end of the bit 2a is formed with a plurality of equally spaced driving blades or wings 22 which are separated by flutes 23.
  • the wings 22 can he formed initially by milling material from the body of the tool to form the fiutes 23 between the wings, or they may also be formed by any other suitable machining or forming operation, such as coining, grinding and the like.
  • the outer surfaces 25 of each of the wings 20 decrease in radial height from the shank of the bit 2-? toward the lower end or tip 26, due to the previously-mentioned taper.
  • Each of the wings 22 is formed with a driving face or surface on one side thereof for engagement with the driven surface 32 of the cruciform-slot or recess 33 of a threaded fastener 34.
  • the slot 33 may be of the common Phillips type as shown in the patent to Phillips 2,046,839 of 1936, which has substantially symmetrically wing receiving slots.
  • the bit 20 of FIGS. l5 is provided with means for confining the major portion of the driving torque to the portion of the wings 22 in the slots 33 adjacent the upper surface 35 of the screw head 35.
  • the means of this embodiment may be seen at FIG. 5 as including a relief 4which is formed in the driving face 30 over the lower axial portion thereof adjacent the tip 26 and preferably uniform over the axial extent thereof, leaving an unrelieved driving zone 42 which conforms to the adjacent driven face 32 of the recess 33 at the region of greatest diameter of the head 36, which is also the region of great est strength and radial dimension of the driving wings
  • the relief may be formed by grinding, coining,
  • the vertical or xial extent of relief 49 on the wings 22 may vary within e lii..'ts, but peferably it extends between fifty and cignty percent of the effective axial extent of the wings 22, leaving a driving zone 42 of from twenty to fifty percent of the effective axial extent of the wings 22 within the scr w slots 33.
  • FIG. 2 The section of FIG. 2 is taken through the zone 42 and shows the driving contact between the driving surface 36* of the wings 22 and the driven faces 32 of the head 3-5.
  • FIGS. 3 and 4 are taken through the portions of the wings forming the relief 43 and show, in slightly exaggerated form, a clearance space 59 between the wings 22 and the face 32 and a lack of effective driving contact throughout the relief zone 4t It will therefore be seen that the relief assures that the driving contact between the wings 22 and the adjacent driven surfaces 32 of the recess 33 is confined to the regions nearest the upper surface 35. This is the region of the greatest mass and strength of the screw head.
  • the modification shown in FIG. 6 is one in which a relief 4% has been formed on both the driving and the reverse driving faces of a wing 22.
  • This embodiment may be of advantage where the tool is to be used for both driving and removing, or where it is more convenient to form the relief 42') uniformly throughout the radial epth of the wings in the walls forming the flutes 23.
  • FIGS. 7-11 The embodiment of the invention shown in FIGS. 7-11 is particularly adapted for use with recesses which are formed with an undercut or a positive lead angle on the driving face.
  • One such recess is shown in enlarged detail in FIG. 8 in which the driving face 68 of the slot 61 is undercut at a lead angle 62.
  • the reverse driving face 64 of the slot 61 may be provided with a normal negative lead angle 65, as shown in United States Patents 2,800,829 and 2,592,462.
  • the bit 70 is formed with four generally equally spaced driving wings 72 separated by smoothly curved flutes 73, which flutes each form a clearance space 72 with the screw slot (FIG. 10).
  • the bit 70 also includes relief means formed on the driving face of each of the wings 72 for limiting the driving contact to regions adjacent the top of the slots 61 and defining a clearance space 76 (FIG. 9) between an inner portion of the wings and the adjacent surface of slot 61.
  • the relief on the driving face 75 of the wings 72 takes the form of either an axially strai it or slightly negative lead angle 80, as shown in exaggerated form in FIG. 11.
  • the relief which is ac cordingly formed in each of the driving faces 75 of the wings 72 is more prominent near the tip 81 of the bit than at locations which are axially remote from the tip for confining the driving contact of the driving surfaces or faces 75 to regions of the greatest radial dimensions of the wings within the fastener recess.
  • undercut angle 62 of the slotted recess be the order of onehalf to one degree, and the lead angle 86 on the driving wing may be in the order of Zero to one degree.
  • the effective relief formed thereby is sufficient when used with undercut screw recesses to assure that the major portion of the driving contact is connned to the area of the screw recess adjacent the upper surface S2 of the fastener.
  • the invention also has the advantage of permitting easy entry into the screw recess and easy removal at the conclusion of the driving, as us better initial fit without experiencing sticking of 4- tlte bit in the recess after the screw fastener is driven, especially when impact type tooling is used.
  • FIGS. 7-11 does not hang up. Also it does not i the effect of increasing the cam out since the total diffcrenence in angle between the driving surface of the wing 72 and the driven face 69 may be in the order of one degree, and the component of force tending to cause the bit to slip out of the recess is considerably less than the coeificient of friction between the bit and the walls of the recess. Also, as shown in FIG. 9, the wings 72 are configured at the reverse driving surfaces for confining contact to the regions that are closely adiacent the common point or tip 81 of the bit, as shown at 95 in FIG. 9, to provide stability of the bit within the recess.
  • a further advantage of the construction of the bit of FIG. 7 resides in the fact that the recesses in screw eads are formed by punches. When the punch enters the material of the screw head there results a falling away of the material of the screw head and when it leaves the recess, it is not always possible in production to assure that an undercut does, in fact, exist .in the recess.
  • Drivers having similarly undercut driving wings when used in such recesses drive at the bottoms of the wings.
  • the relief formed on the driving wings of the bit 70 assures that the driving force is confined on the wings at the areas of greatest strength, over a wide variation in screw recesses between the achievement of an actual undercut and recesses in which this is not fully achieved.
  • this invention provides driver bits formed with a relief at least on the driving surfaces of the wings, with the relief being more prominent near the tip of the bits than at locations axially removed from the tip for confining the driving contact of the wings to regions axially remote from the tips.
  • a driver tool adapted for driving screw threaded fasteners characterized by a cruciform-slot comprising a body, a plurality of driving wings on said body extending axially from a tip of said body separated by flutes, each of said wings having a driving surface formed on one face thereof and extending generally uniformly radially thereof, arTd relief means formed in each of said wings on said driving face between an axially inner portion of each of said wings adjacent said tip and the adjacent driven surface of such a fastener slot confining driving contact to an axial region on said wings remote from said tip.
  • a driver tool adapted for driving screw threaded fasteners characterized by a cruciform slot comprising a body, a plurality of generally comically tapered driving wings on said body-separated by flutes extending axially of said body and terminating in a tip, each of said wings having a driving surface formed on one face thereof ex-- tending generally uniformly radially thereof, and means in each of said wings at said driving surface forming a relief adjacent said tip and positioned axially inwardly of the top of such a fastener slot limiting driving contact of each of said wings to a region of greatest radial diameter of said wings within the screw slot.
  • a driver tool adapted for driving screw threaded fasteners characterized by a cruciform recess comprising a driver body, a plurality of driving wings on said body terminating in a tip and separated from each other by flutes, each of said wings having a driving surface formed on one face thereof and extending generally uniformly radially thereof, and means on each of said wings defining a relief on each of said faces which is more prominent near said tip of said bit than at locations axially removed from said tip for confining the driving contact of said wngs with such a recess to regions axially spaced from said tip.
  • a driver bit for use with power tools adapted for driving screw threaded fasteners characterized by a cruciform recess comprising a driver body, a plurality of equally spaced driving wings in said body extending axially and terminating in a common tip, each of said wings having a forward driving surface and a reverse driving surface formed on opposite faces thereof, and means on each of said wings forming a relief in each of said forward driving surfaces with said relief being more prominent near the tip of said bit than at locations axially removed from said tip for confining the driving contacts of said forward driving surfaces to regions on said wings which are axially spaced from said bit tip.
  • a bit for use with power tools and the like adapted for driving threaded fastencrshaving a cruciform driving recess comprising a bit body, means on said body defining a plurality of generally equally spaced driving wings extending axially thereof and terminating in a common bit point, each of said wings having a forward driving surfacev on one face thereof and a reverse driving surface formed on the opposite face thereof, means on each of said wings forming a relief in said forward driving surfaces with said relief being more prominent near the said common point of said wings than at locations which are axially spaced from said point for confining the driving contacts of said forward driving surfaces to regions on said wings which are axially spaced from said common point, and said wings being further configured at said reverse driving surfaces confining contact of said reverse surfaces to regions closely adjacent said bit common point providing stability of the bit within such recess.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
  • Percussive Tools And Related Accessories (AREA)
  • Portable Nailing Machines And Staplers (AREA)
US289996A 1963-06-24 1963-06-24 Driver for recessed head fasteners Expired - Lifetime US3234982A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US289996A US3234982A (en) 1963-06-24 1963-06-24 Driver for recessed head fasteners
DE19641478789 DE1478789A1 (de) 1963-06-24 1964-06-23 Mitnehmer fuer Befestigungsmittel mit einem mit Nuten versehenen Kopfstueck
GB25982/64A GB1074206A (en) 1963-06-24 1964-06-23 Driver for recessed head screw threaded fasteners

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US289996A US3234982A (en) 1963-06-24 1963-06-24 Driver for recessed head fasteners

Publications (1)

Publication Number Publication Date
US3234982A true US3234982A (en) 1966-02-15

Family

ID=23114082

Family Applications (1)

Application Number Title Priority Date Filing Date
US289996A Expired - Lifetime US3234982A (en) 1963-06-24 1963-06-24 Driver for recessed head fasteners

Country Status (3)

Country Link
US (1) US3234982A (de)
DE (1) DE1478789A1 (de)
GB (1) GB1074206A (de)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3654974A (en) * 1970-04-08 1972-04-11 Bertron Otis Barnes Screw drivers
FR2319046A1 (fr) * 1975-07-19 1977-02-18 Gkn Fasteners Ltd Vis a empreinte cruciforme
EP0006139A1 (de) * 1978-06-20 1980-01-09 Anton Gerhard Zur Aufnahme einer Abdeckkappe geeignete Kreuzschlitz-Schraube und Verfahren zu ihrer Herstellung
US4998454A (en) * 1988-11-14 1991-03-12 Black & Decker Inc. Screwdriver bit for phillips-head fasteners
AU665621B2 (en) * 1988-11-14 1996-01-11 Black & Decker Incorporated Improved screwdriver bit for phillips-head fasteners
WO1998024597A1 (de) * 1996-12-05 1998-06-11 Wera Werk Hermann Werner Gmbh & Co. Schraubendreher oder schraubendrehereinsatz
US6378406B1 (en) * 1998-02-24 2002-04-30 Katsuyuki Totsu Combination of driver bit and screw
US20070028728A1 (en) * 2005-08-03 2007-02-08 Bryan Griffiths Screw-retaining screwdriver
US20100104397A1 (en) * 2007-06-27 2010-04-29 Terufumi Nojikawa Screw and driver bit
WO2013028656A1 (en) * 2011-08-25 2013-02-28 Infastech Intellectual Properties Pte. Ltd. Negative drive angle
CN102995504A (zh) * 2012-12-07 2013-03-27 宁波金鼎紧固件有限公司 一种铁路轨道用螺栓
US8955418B2 (en) 2013-03-08 2015-02-17 Black & Decker Inc. Threaded fastener driving tool

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2800829A (en) * 1954-08-30 1957-07-30 Wesloc Screw Inc Cruciform recessed screw

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2800829A (en) * 1954-08-30 1957-07-30 Wesloc Screw Inc Cruciform recessed screw

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3654974A (en) * 1970-04-08 1972-04-11 Bertron Otis Barnes Screw drivers
FR2319046A1 (fr) * 1975-07-19 1977-02-18 Gkn Fasteners Ltd Vis a empreinte cruciforme
EP0006139A1 (de) * 1978-06-20 1980-01-09 Anton Gerhard Zur Aufnahme einer Abdeckkappe geeignete Kreuzschlitz-Schraube und Verfahren zu ihrer Herstellung
US4998454A (en) * 1988-11-14 1991-03-12 Black & Decker Inc. Screwdriver bit for phillips-head fasteners
AU665621B2 (en) * 1988-11-14 1996-01-11 Black & Decker Incorporated Improved screwdriver bit for phillips-head fasteners
WO1998024597A1 (de) * 1996-12-05 1998-06-11 Wera Werk Hermann Werner Gmbh & Co. Schraubendreher oder schraubendrehereinsatz
US6520055B1 (en) 1996-12-05 2003-02-18 Wera Werk Hermann Werner Gmbh & Co. Screwdriver or screwdriver attachment
US6378406B1 (en) * 1998-02-24 2002-04-30 Katsuyuki Totsu Combination of driver bit and screw
US20070028728A1 (en) * 2005-08-03 2007-02-08 Bryan Griffiths Screw-retaining screwdriver
US7690282B2 (en) * 2005-08-03 2010-04-06 Synthes Usa, Llc Screw-retaining screwdriver
US20100104397A1 (en) * 2007-06-27 2010-04-29 Terufumi Nojikawa Screw and driver bit
US8261641B2 (en) * 2007-06-27 2012-09-11 Terufumi Nojikawa Screw and driver bit
WO2013028656A1 (en) * 2011-08-25 2013-02-28 Infastech Intellectual Properties Pte. Ltd. Negative drive angle
JP2014529044A (ja) * 2011-08-25 2014-10-30 インファステック インテレクチュアル プロパティーズ ピーティーイー．リミテッド 負の駆動角度
KR20170135995A (ko) * 2011-08-25 2017-12-08 인파스텍 인텔렉츄얼 프로퍼티즈 피티이. 엘티디. 음의 구동 각도
CN102995504A (zh) * 2012-12-07 2013-03-27 宁波金鼎紧固件有限公司 一种铁路轨道用螺栓
US8955418B2 (en) 2013-03-08 2015-02-17 Black & Decker Inc. Threaded fastener driving tool

Also Published As

Publication number Publication date
GB1074206A (en) 1967-06-28
DE1478789A1 (de) 1969-03-13

Similar Documents

Publication Publication Date Title
US4671141A (en) Rotary torque device
US3234982A (en) Driver for recessed head fasteners
US4607547A (en) Stripped hex head drive socket
US4269246A (en) Fastener and driver assembly
EP2747944B1 (de) Konischer wälzkolbentreiber und befestigungselement
JP5536163B2 (ja) ネジ山付留め具のための渦巻型駆動システム
US2147343A (en) Friction joint
US4126063A (en) Wrench sockets
AU625266B2 (en) Improved winged drill screw
US2474994A (en) Screw socket
US6098499A (en) Bolt extraction tool
EP3337644B1 (de) Konischer wälzkolbentreiber und befestigungselement
US2601453A (en) Driving tool for socket head fasteners
US4480514A (en) Driving tool for tamper resistant screw
US2046840A (en) Screw driver
EP0046010B1 (de) Schrauben und Schraubenzieher-Kombination
US2182568A (en) Screw
US4429599A (en) One way screwdriver
JPH11173315A (ja) ねじ及びドライバービットまたはレンチとの組合せ
US2121197A (en) Screw extractor
US3093028A (en) Self-drilling and self-tapping threaded fastener
US10968939B2 (en) Tapered lobular driver and fastener
EP3191260B1 (de) Konischer wälzkolbentreiber und befestigungselement
US6152000A (en) Driver bit and driver
US4151621A (en) Tools for punching fastener heads