US2847894A - Socketed screw head with uniformly offset grooves - Google Patents

Socketed screw head with uniformly offset grooves Download PDF

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Publication number
US2847894A
US2847894A US494726A US49472655A US2847894A US 2847894 A US2847894 A US 2847894A US 494726 A US494726 A US 494726A US 49472655 A US49472655 A US 49472655A US 2847894 A US2847894 A US 2847894A
Authority
US
United States
Prior art keywords
recess
screw
walls
grooves
driving
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
US494726A
Other languages
English (en)
Inventor
Ian A Smith
Herman G Muenchinger
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.)
AMERICAN SCREW CO
Original Assignee
AMERICAN SCREW 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
Priority to BE546137D priority Critical patent/BE546137A/xx
Priority to NL100665D priority patent/NL100665C/xx
Priority to US24878D priority patent/USRE24878E/en
Priority to NL205416D priority patent/NL205416A/xx
Priority to US494726A priority patent/US2847894A/en
Application filed by AMERICAN SCREW CO filed Critical AMERICAN SCREW CO
Priority to DEA24425A priority patent/DE1055887B/de
Priority to GB8204/56A priority patent/GB789272A/en
Priority to FR1148891D priority patent/FR1148891A/fr
Application granted granted Critical
Publication of US2847894A publication Critical patent/US2847894A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • 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
    • F16B23/0023—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 substantially cross-shaped
    • 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 threaded fasteners, and more particularly to recessed head screws, bolts and thelike.
  • the recess of the Phillipstype cannot be increased in size or penetration beyond a certain proportion with respect to the size of the fastener, because of the relative proportions of the recessitse'lf. That is, when the overall size of the recess is increased beyond a certain extent, the central portion-of the recess penetrates below the depth of the fastener head and intoth'e shank, thus undesirably weakening the screw at an already critical point, namely, the junction of-the head and shank.
  • Driver wing deflection takes the form of a spiral deformation of the wings. That is, since the upper edges of the'wings are integral with the shank of the driver bit the wing deflection, measured in degrees, increases downwardly toward the'tip of the driver bit. The result is a spiral deformation of the wings, causing a reaction the axial component of which is a force tending to throw the driver out of the recess, and which also enhances the rock-out eifect.
  • T he torque capacityof the screw and driver combinations heretofore has alsobeen subject to limitation by reason of the design of the driver tip, which is of course substantially complementary to the screw recess. If the recess has a sufficiently high torque capacity, the overallcapacity of the combination may depend upon the capacity of the driver, failure ofthe latter frequently occurring due to an inadequate strength through the'central portion of the driver'tip, corresponding to the central portion of the screw head recess.
  • Thegeneral object of the present invention is the provision of .athreaded fastenerhaving a tool-receiving recess designed to impart a maximum torque capacity to the screw itself, while atthe same'time eliminating the aforesaid rock-out characteristic, and also permitting the use of a stronger driving tool, 'all of which factors result in asu'bstant'ial increase in the overall torque capacity of the "screw and driver combination, and increase its usefulness.
  • 7 ,A :further object of Lthe invention is the provision of .a zthreaded-fastener having a recessed head, the recess of which is designed so that for a given torque capacity of the fastener, a tool having larger torque capacity is accommodated, thus increasing the overall capacity of the screw and driver combination.
  • the physical diameter of the central portion is increased, so that a stronger driver may be used.
  • Another object is the provision of a threaded fastener having a recess of the type described above, the substantially radial grooves being arranged in angularly spaced, oppositely directed pairs, the grooves of each pair being staggered ordisplaced with respect to each other so as to eliminate rock-out and permit the use of a driver having a larger central portion.
  • Another object is the provision of a fastener having a recess such as described above, and provided also with a pilot recess at thebottom of the driving recess, as a further insurance against rock-out.
  • Figure 1 is a plan view of the head of a fastener provided with a recess according to the present invention
  • Figure 2 is a vertical section on line 2-2 of ure 1;
  • Figure 3 is a view similar to Figure 2, but illustrating a modification containing an additional feature
  • Figures 4, 5 and 6 are partial plan views illustrating further modifications of the recess of Figure 1.
  • the screw head 10 is provided, centrally thereof, with a recess designated generally by the reference numeral 11, which Figrecess consists of a central portion 12 and four gen erally radially extending grooves 13 which terminate substantially inwardly of the outer periphery of the screw head.
  • Each groove 13 is bounded by a bottom wall 14 and side walls 15 and 16.
  • the side wall 15 disposed on the clockwise side of the groove will be hereinafter called the driving wall of the groove.
  • the driving wall of each groove is connected with the wall 16 of the adjacent groove through the intermediary of walls 17 and 18 which bound the central portion 12 of the recess and which intersect each other, and the adjacent groove walls, at obtuse angles.
  • the bottom walls 14 of the respective grooves 13 intersect the shallow conical bottom wall 19 of the central portion 12 along arcuate lines 20, while the walls 17 and 18 of the central portion 12 also intersect the bottom wall 19 along their lower edges.
  • the groove walls 15 and 16 have been illustrated as vertical, that is as occupying planes parallel to the longitudinal axis of the screw, while the walls 17 and 18 of the central recess portion 12 have been illustrated as having a slight vertical taper or upward flare.
  • This particular characteristic or arrangement is not critical, the presence or absence of slight amounts of vertical taper in the walls of the grooves, or of the central portion of the screw recess, depending upon the design of the header punch used in producing the recess, the composition and temper of the metal stock of which the screw or other fastener is formed and other factors not necessary to detail.
  • the recess produced by the punch at least in certain materials, will have some degree of vertical taper. Also, this vertical taper may be somewhat reduced, or perhaps eliminated, by the impact of the end surface of the punch, surrounding the punch nib, upon the head of the fastener at the end of the forward movement of the punch.
  • the groove side walls 15 and 16, as well as the walls 17 and 18 of the central recess portion 12 should be substantially vertical, but not necessarily entirely without vertical taper.
  • the groove side walls 15 and 16, and particularly the driving walls 15, are substantially without horizontal taper. That is, the walls 15 and 16 are preferably parallel to each other and to a true radial plane extend- .ing into the groove or coinciding with the driving wall 15 ( Figure 6).
  • a tool of complementary shape may easily be rocked or inclined laterally, in the direction of either pair of grooves, or at 45 thereto, until the tool is unseated from the recess. If power is applied while the tool is in a position substantially inclined to the screw axis, the tool may jump out of the recess, injuring the recess and marring the work, or the recess may be reamed, or the tool may be broken. These damaging results cannot occur with the recess of the present invention.
  • the wall 15 is of somewhat less area than the corresponding wall of a conventional recess 21 having the same overall width, the driving torque which can be transmitted through the walls 15 is as great as, or greater than, the torque which can be transmitted through the corresponding wall of a conventional recess 21, the force being largely concentrated, in the latter case, toward the outer boundary of the driving wall and of the corresponding wing wall of the driver. It is therefore evident that a smaller crushing force, per unit of area, is acting upon the driving walls 15 of the present recess than that which J acts upon the outer areas of the drivingwalls ofthe conventional recess 21, when the same total torque is applied in each case.
  • the anti-rock-out characteristic of the recess may be further enhanced by providing a cylindrical extension 24 at the bottom of the recess 11, to receive and closely engage a complementary projection formed on the end of the driving tool.
  • Figure 6 illustrates an embodiment in which the driving walls 15 lie on true radial planes, which is the preferred arrangement insofar as the driving walls are concerned.
  • the walls of the central recess portion may be arranged in either of the several ways illustrated in Figures 1, 4 and 5, and the cylindrical extension or pilot recess 24 may be employed or not, as desired.
  • the recess of the present invention has been illustrated as bearing the same proportion to the screw size, in width, as the conventional recess 21, obviously the recess of the invention can be made considerably wider in proportion to the screw head, since it is shallower in design. That is, it is possible to increase the overall size of the improved recess, relative to the fastener in which it is used, without penetrating the shank of the fastener and thus weakening the fastener at the junction of the head and shank.
  • vertical medial plane is intended to signify a plane which is substantially parallel to the screw axis and contains (1) the midpoint of a line joining the intersections of the respective groove walls 15 and 16 with the outer edge of the bottom wall 14, and (2) the midpoint of a line joining the intersections of the respective groove walls with the inner edge of the bottom wall.
  • the vertical medial plane of each groove will be exactly parallel to some radial plane (i. e. a plane containing the screw axis). If the respective walls 15 and 16 differ in vertical taper the vertical medial plane will have a slight inclination to the screw axis and thus to any radial plane, while if the walls 15 and 16 differ in horizontal taper, but not in vertical taper, the vertical medial plane will nevertheless be parallel to a true radial plane.
  • the true radial plane to which the side walls of each groove are referred is that radial plane to which the vertical medial plane is most nearly parallel.
  • a screw having a recess extending into its upper end along its longitudinal axis and comprising a central portion having a concave bottom in the general form of an inverted cone and at least three angularly equidistant grooves extending outwardly therefrom and terminating substantially inwardly of the outer periphery of said upper end, each said groove having a substantially vertical driving side wall, an opposite substantially vertical side wall, and a bottom wall intersecting said respective side walls, said grooves extending generally radially and having their bottoms inclined upwardly and outwardly,
  • said grooves having their vertical medial planes substantially parallel to, but displaced from, true radial planes, the driving wall of each said groove lying closer to said 8 respective substantially parallel true radial plane than does the opposite wall of the same groove.
  • a screw having a recess as defined in claim 1, said driving walls lying in planes parallel to said true radial planes.
  • a screw having a recess as defined in claim 1, said groove walls lying in planes parallel to said true radial planes.
  • a screw having a recess as defined in claim 1, said driving walls lying in said radial planes.
  • a screw having a recess as defined in claim 1, adjacent walls of adjacent grooves being connected by surfaces of said central portion which surfaces are arranged asymmetrically with respect to any plane containing said screw axis.
  • a screw having a recess as defined in claim 5, said central portion surfaces comprising a single curved surface between each two grooves.
  • a screw having a recess as defined in claim 1, said central portion having a cylindrical extension at the bottom, said cylindrical extension being concentric with said longitudinal screw axis.
  • a screw having a recess as defined in claim 1, said driving walls lying substantially in said radial planes, and said opposite groove walls being substantially parallel to said radial planes.
  • a screw having a recess extending into its upper end along its longitudinal axis and comprising a central portion having a concave bottom in the general form of an inverted cone and grooves extending outwardly therefrom and terminating substantially inwardly of the outer periphery of said upper end, each said groove having a substantially vertical driving side wall, an opposite substantially vertical side wall, and a bottom wall intersecting said respective side walls, said grooves extending generally radially and having their bottoms inclined up wardly and outwardly, said grooves having their vertical medial planes substantially parallel to, but displaced from, true radial planes, the driving wall of each said groove lying closer to said respective substantially parallel true radial plane than does the opposite wall of the same groove, said grooves being arranged in angularly spaced, oppositely directed pairs.
  • a screw having a recess as defined in claim 11, said driving walls lying in planes parallel to said true radial planes.
  • a screw having a recess as defined in claini 11, said groove walls lying in planes parallel to said true radial planes.
  • a screw having a recess as defined in claim 11, said driving walls lying in said radial planes.
  • a screw having a recess as defined in claim 11, adjacent walls of adjacent grooves being connected by surfaces of said central portion which surfaces are arranged asymmetrically with respect to any plane containing said screw axis.
  • a screw having a recess as defined in claim 15, said central portion surfaces comprising a single plane surface between each two grooves.
  • a screw having a recess as defined in claim 15, said central portion surfaces comprising a single curved surface between each two grooves.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
  • Surgical Instruments (AREA)
  • Portable Nailing Machines And Staplers (AREA)
  • Joining Of Building Structures In Genera (AREA)
US494726A 1955-03-16 1955-03-16 Socketed screw head with uniformly offset grooves Expired - Lifetime US2847894A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
US24878D USRE24878E (en) 1955-03-16 Socketed screw head with uniformly offset grooves
NL205416D NL205416A (ko) 1955-03-16
BE546137D BE546137A (ko) 1955-03-16
NL100665D NL100665C (ko) 1955-03-16
US494726A US2847894A (en) 1955-03-16 1955-03-16 Socketed screw head with uniformly offset grooves
DEA24425A DE1055887B (de) 1955-03-16 1956-03-05 Schraube mit einem Kopfteil, der eine zentrale Ausnehmung und eine Anzahl radial davon ausgehender Nuten aufweist
GB8204/56A GB789272A (en) 1955-03-16 1956-03-15 Improvements in and relating to screws
FR1148891D FR1148891A (fr) 1955-03-16 1956-03-16 Vis à tête évidée

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US494726A US2847894A (en) 1955-03-16 1955-03-16 Socketed screw head with uniformly offset grooves

Publications (1)

Publication Number Publication Date
US2847894A true US2847894A (en) 1958-08-19

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Family Applications (2)

Application Number Title Priority Date Filing Date
US24878D Expired USRE24878E (en) 1955-03-16 Socketed screw head with uniformly offset grooves
US494726A Expired - Lifetime US2847894A (en) 1955-03-16 1955-03-16 Socketed screw head with uniformly offset grooves

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US24878D Expired USRE24878E (en) 1955-03-16 Socketed screw head with uniformly offset grooves

Country Status (6)

Country Link
US (2) US2847894A (ko)
BE (1) BE546137A (ko)
DE (1) DE1055887B (ko)
FR (1) FR1148891A (ko)
GB (1) GB789272A (ko)
NL (2) NL100665C (ko)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1172904B (de) * 1961-01-26 1964-06-25 Aer O Terq Inc Kreuzschlitz fuer Kopfschrauben
US3187790A (en) * 1959-05-18 1965-06-08 Hi Shear Rivet Tool Company Screw and screw driver coupling
US3288190A (en) * 1964-09-21 1966-11-29 John F Holmes Self-locking screw with friction reducing driving means
US3494243A (en) * 1967-06-28 1970-02-10 Standard Pressed Steel Co Sealing fastener
US4084478A (en) * 1974-09-12 1978-04-18 Phillips Screw Company Screw heads
EP0038031A1 (en) * 1980-04-14 1981-10-21 Technofast, Inc. Recessed head screw
USD270229S (en) 1980-10-22 1983-08-23 The Eastern Company Tool and operator head for tool-operated lock
USD270424S (en) 1980-10-22 1983-09-06 The Eastern Company Tool operator for tool-operated locks
US4998454A (en) * 1988-11-14 1991-03-12 Black & Decker Inc. Screwdriver bit for phillips-head fasteners
US6164171A (en) * 1998-03-13 2000-12-26 Max Co., Ltd. Screwdriver used for screw tightener and screw suitably tightened by the screwdriver
US6199455B1 (en) 1999-03-08 2001-03-13 Jjct Enterprises, Inc. Driver, fastener and forming tool
US6520055B1 (en) * 1996-12-05 2003-02-18 Wera Werk Hermann Werner Gmbh & Co. Screwdriver or screwdriver attachment

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3170364A (en) * 1963-05-06 1965-02-23 Robert K Johnson Recessed head screw
US6223634B1 (en) * 1997-10-03 2001-05-01 Phillips Screw Company Recessed head fastener and driver systems
US5957645A (en) 1997-10-31 1999-09-28 Phillips Screw Company Spiral drive system for threaded fasteners
US7293949B2 (en) * 2004-04-15 2007-11-13 Phillips Screw Company Spiral drive fastener with friction engageable surface
US7316535B2 (en) * 2005-11-14 2008-01-08 Ling-Fang Chen Screw with a convenient screw head
EP2283241A4 (en) * 2008-04-21 2012-04-04 Asia Fastening Us Inc TRAINING SYSTEM
US8291795B2 (en) 2010-03-02 2012-10-23 Phillips Screw Company Fastener system with stable engagement and stick fit
US11466720B2 (en) 2017-12-15 2022-10-11 Phillips Screw Company Stick fit fastener recess system
US10995788B2 (en) 2017-12-15 2021-05-04 Phillips Screw Company Stick fit fastener recess system

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US101207A (en) * 1870-03-29 Improvement in screw and screw-driver
USRE15483E (en) * 1922-10-31 stirling
US1797390A (en) * 1929-02-04 1931-03-24 Frederick H Wood Screw driver designed to be keyed on a screw
US1956963A (en) * 1931-05-09 1934-05-01 Jr Fred Salmen One way screw
US2216382A (en) * 1939-11-01 1940-10-01 W H Holmes Screw
US2304704A (en) * 1939-12-04 1942-12-08 Winslow Foster Screw
US2445978A (en) * 1945-05-07 1948-07-27 Domnic V Stellin Socket head screw

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT175424B (de) * 1942-12-30 1953-07-10 Guest Keen & Nettlefolds Ltd Schraube, deren Kopf für den Angriff eines Schraubenziehers eine Ausnehmung aufweist
US2592462A (en) * 1951-09-11 1952-04-08 Res Eng & Mfg Recessed head fastener

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US101207A (en) * 1870-03-29 Improvement in screw and screw-driver
USRE15483E (en) * 1922-10-31 stirling
US1797390A (en) * 1929-02-04 1931-03-24 Frederick H Wood Screw driver designed to be keyed on a screw
US1956963A (en) * 1931-05-09 1934-05-01 Jr Fred Salmen One way screw
US2216382A (en) * 1939-11-01 1940-10-01 W H Holmes Screw
US2304704A (en) * 1939-12-04 1942-12-08 Winslow Foster Screw
US2445978A (en) * 1945-05-07 1948-07-27 Domnic V Stellin Socket head screw

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3187790A (en) * 1959-05-18 1965-06-08 Hi Shear Rivet Tool Company Screw and screw driver coupling
DE1172904B (de) * 1961-01-26 1964-06-25 Aer O Terq Inc Kreuzschlitz fuer Kopfschrauben
US3288190A (en) * 1964-09-21 1966-11-29 John F Holmes Self-locking screw with friction reducing driving means
US3494243A (en) * 1967-06-28 1970-02-10 Standard Pressed Steel Co Sealing fastener
US4084478A (en) * 1974-09-12 1978-04-18 Phillips Screw Company Screw heads
EP0038031A1 (en) * 1980-04-14 1981-10-21 Technofast, Inc. Recessed head screw
USD270229S (en) 1980-10-22 1983-08-23 The Eastern Company Tool and operator head for tool-operated lock
USD270424S (en) 1980-10-22 1983-09-06 The Eastern Company Tool operator for tool-operated locks
US4998454A (en) * 1988-11-14 1991-03-12 Black & Decker Inc. Screwdriver bit for phillips-head fasteners
US6520055B1 (en) * 1996-12-05 2003-02-18 Wera Werk Hermann Werner Gmbh & Co. Screwdriver or screwdriver attachment
US6164171A (en) * 1998-03-13 2000-12-26 Max Co., Ltd. Screwdriver used for screw tightener and screw suitably tightened by the screwdriver
US6199455B1 (en) 1999-03-08 2001-03-13 Jjct Enterprises, Inc. Driver, fastener and forming tool
US6575061B2 (en) 1999-03-08 2003-06-10 John B. Wagner Driver, fastener and forming tool

Also Published As

Publication number Publication date
NL100665C (ko)
USRE24878E (en) 1960-09-27
GB789272A (en) 1958-01-15
DE1055887B (de) 1959-04-23
BE546137A (ko)
FR1148891A (fr) 1957-12-17
NL205416A (ko)

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