Fastener wrenching means

Claim 2

A fastener comprising: a member having a shank and a hEad; said head having an axially outer end surface remote from said shank; and being provided with a recess extending axially inwardly of said outer end surface; said recess having a central portion at the axis of said member and a plurality of pockets communicating with said central portion and extending radially outwardly therefrom so as to leave intermediate portions of said head between adjacent ones of said pockets; said pockets and said intermediate portions being of substantially the same width; said pockets having substantially radial sidewalls; said central portion of said recess and radially inner portions of said pockets having a first axially inner end wall defined by a segment of a sphere; the radially outer portions of said pockets having second axially inner end walls connecting to said first axially inner end wall and smoothly faired relative thereto, said second axially inner end walls being defined by segments of a cone; said intermediate portions having radially inner faces around said central portion of said recess substantially parallel to the axis of said member.

Claim 3

A device as in claim 1 in which the maximum radial dimension of said recess at said outer end surface is equal to approximately 1.18 times the diameter of said shank.

Claim 4

A device as recited in claim 1 in which said inner faces of said intermediate portions are spaced from said axis by a distance equal to approximately 1.18 times the diameter of said shank divided by 8.

Claim 5

A device as recited in claim 1 in which the maximum depth of said recess is equal to approximately 0.88 times the axial length of said head.

Claim 6

A device as recited in claim 1 in which said first axially inner end wall has a radius equal to approximately 2.31 times the distance said inner faces are spaced from said axis.

Claim 7

A fastener comprising: a member having a portion adapted for connection to another element upon relative rotation of said member and said element; said member having a recess therein; said recess having a central portion and a plurality of pockets communicating with said central portion and extending outwardly therefrom; said pockets being of substantially the same width and being substantially equally spaced-apart angularly; said pockets defining intermediate portions of said member therebetween which are substantially equal in widths to the widths of said pockets; each of said pockets including two side edges for engagement for a driving tool for applying torque to said member; said two side edges of each of said pockets being in opposed relationship; said two side edges of each of said pockets being planar and positioned such that projections thereof would intersect at the longitudinal axis of said member; said intermediate portions including inner surface portion around central portion of said recess; said inner surface portions being substantially parallel to said longitudinal axis; said pockets having radially outer and axially inner end surface portions defined by conical segments; said central portion of said recess having an axially inner end surface defined by a segment of a sphere.

Claim 8

A fastener comprising: a member having a portion adapted for connection to another element upon relative rotation of said member and said element; said member having a recess therein; said recess having a central portion and a plurality of pockets communicating with said central portion and extending outwardly therefrom; said pockets being of substantially the same width and being substantially equally spaced-apart angularly; said pockets defining intermediate portions of said member therebetween which are substantially equal in widths to the widths of said pockets; each of said pockets including two side edges for engagement for a driving tool for applying torque to said member; said two side edges of each of said pockets being in opposed relationship; said two side edges of each of said pockets being planar and positioned such that projections thereof would intersect at the longitudinal axis of said member; said intermediate portions including inner surface portion around central portion of said recess; said inner surface portions being substantially parallel to said longitudinal axis; said pockets having radially outer and axially inner end surface portions defined by conical segments; said central portion of said recess having an axially inner end surface defined by a segment of a sphere.

Claim 9

A device as recited in claim 6 in which said conical segments are substantially tangent to said inner end surface of said central portion.

Claim 10

A fastener comprising: a member having a portion adapted for connection to another element upon relative rotation of said member and said element; said member having a recess therein; said recess having a central portion and a plurality of pockets communicating with said central portion and extending outwardly therefrom; said pockets being of substantially the same width and being substantially equally spaced-apart angularly; said pockets defining intermediate portions of said member therebetween which are substantially equal in widths to the widths of said pockets; each of said pockets hAving two side edges for engagement with a driving tool for applying torque to said member; said two side edges being in opposed relationship said recess including first radially outer and axially inner surfaces intermediate side edges; said first surfaces being defined by conical segments; said recess including a second arcuate radially and axially inner surface connected to said first surfaces and smoothly faired relative thereto; said intermediate portions including generally axially directed inner surface portions around said central portion of said recess; said inner surface portions being substantially equal in widths to the widths of the inner ends of said pockets.

Claim 11

A fastener comprising: a member having a portion adapted for connection to another element upon relative rotation of said member and said element; said member having a recess therein; said recess having a central portion and a plurality of pockets communicating with said central portion and extending outwardly therefrom; said pockets being of substantially the same width and being substantially equally spaced-apart angularly; said pockets defining intermediate portions of said member therebetween which are substantially equal in widths to the widths of said pockets; each of said pockets hAving two side edges for engagement with a driving tool for applying torque to said member; said two side edges being in opposed relationship said recess including first radially outer and axially inner surfaces intermediate side edges; said first surfaces being defined by conical segments; said recess including a second arcuate radially and axially inner surface connected to said first surfaces and smoothly faired relative thereto; said intermediate portions including generally axially directed inner surface portions around said central portion of said recess; said inner surface portions being substantially equal in widths to the widths of the inner ends of said pockets.

Claim 12

A driving tool for a rotatable fastener comprising: an elongated member having a plurality of substantially longitudinally extending flutes separated by substantially longitudinally extending recesses; said flutes being of substantially the same width and being substantially longitudinally extending recesses; said flutes being of substantially the same width and being substantially equally spaced angularly; said recesses being of substantially the same widths as the widths of said flutes; said flutes having substantially radial sidewalls defining the sidewalls of said recesses such that each of said recesses includes a pair of said sidewalls in opposed relationship; said flutes being joined in the axial portion of said member and presenting surfaces interconnecting said sidewalls at the radially inner portions of said recesses; said interconnecting surfaces being relatively narrow with respect to said sidewalls and substantially parallel to the axis of said member; said flutes and recess terminating at an axially outer end wall of said member; said end wall along at least portions of said flutes being defined by outer substantially conical segments connected and faired smoothly with a convex arcuate central portion of said end wall.

Claim 13

A driving tool for a rotatable fastener comprising: an elongated member having a plurality of substantially longitudinally extending flutes separated by substantially longitudinally extending recesses; said flutes being of substantially the same width and being substantially longitudinally extending recesses; said flutes being of substantially the same width and being substantially equally spaced angularly; said recesses being of substantially the same widths as the widths of said flutes; said flutes having substantially radial sidewalls defining the sidewalls of said recesses such that each of said recesses includes a pair of said sidewalls in opposed relationship; said flutes being joined in the axial portion of said member and presenting surfaces interconnecting said sidewalls at the radially inner portions of said recesses; said interconnecting surfaces being relatively narrow with respect to said sidewalls and substantially parallel to the axis of said member; said flutes and recess terminating at an axially outer end wall of said member; said end wall along at least portions of said flutes being defined by outer substantially conical segments connected and faired smoothly with a convex arcuate central portion of said end wall.

Claim 14

A device as recited in claim 9 in which said central portion of said end wall is substantially spherical.