Safety bolt

Claim 2

A safety bolt comprising: an element having a shank with an axis and an unthreaded portion, the element having a first headed end and a second threaded end, an axial passage opening onto said second end, and a laterally extending passage opening onto the shank and intersecting the axial passage; a dog slideably mounted between extended and retracted positions in said laterally extending passage whereby the dog extends beyond the maximum diameter of the shank in the extended position and retracts entirely within said shank in the retracted position, said dog including a planar restraint surface which lies normal to the said axis and faces the headed end, whereby it is adapted to abut the back side of a body into which the shank is inserted, a retraction surface facing toward the threaded end and sloping inwardly toward it, both of said surfaces being adapted to project beyond the radius of the unthreaded portion of the shank, whereby the restraint surface, when extended, prevents the removal of the bolt by a force exerted in shear, and the retraction surface is adapted to engage the said body in order for the dog to be retracted into the bolt while the shank is being pressed into a hole in the body, the dog fully occupying the laterally extending passage in cross section to create such shear relationship; a cam member movable in said axial passage and reactive with said dog to retract the same; and bias means forcing the dog toward its extended position independently of the position of the cam member.

Claim 3

A safety bolt according to claim 1 in which said dog and cam member each has a camming surface mutually reactive to retract the dog.

Claim 4

A safety bolt according to claim 2 in which the cam member is axially movable, and in which the camming surfaces are slanted relative to said axis.

Claim 5

A safety bolt according to claim 2 in which the cam member is rotatable, and in which at least one of the cam surfaces has a plurality of regions at different radial spacings from the axis.

Claim 6

A safety bolt according to claim 2 in which safetying means is provided to secure the cam member against movement.

Claim 7

In combination: a safety bolt comprising an element having a shank with an axis and an unthreaded portion, the element having a first headed end and a second threaded end, an axial passage opening onto said second end, a laterally extending passage opening onto the shank and intersecting the axial passage, a dog slideably mounted between extended and retracted positions in said laterally extending passage whereby the dog extends beyond the maximum diameter of the shank in the extended position and retracts entirely within said shank in the retracted position, said dog including a planar restraint surface which lies normal to the said axis and faces the headed end, whereby it is adapted to abut the back side of a body into which the shank is inserted, a retraction surface facing toward the threaded end and sloping inwardly toward it, both of said surfaces being adapted to project beyond the radius of the unthreaded portion of the shank, whereby the restraint surface, when extended, prevents the removal of the bolt by a force exerted in shear and the retraction surface is adapted to engage the said body in order for the dog to be retracted into the bolt while the shank is being pressed into a hole in the body, the dog fully occupying the laterally extending passage in cross section to create such shear relationship, said dog including a ratchet face and a sloping retraction face, and a cam member movable in said axial passage and reactive with said dog to retract the same, bias means forcing the dog toward its extended position, and a nut threadable onto the threaded end having a plurality of ratchet faces in a counterbore, whereby tightening the nut onto the threads causes the dog to ratchet along the ratchet faces of the nut, and the ratchet faces to engage and resist unthreading of the nut from the bolt.

Claim 8

In combination: a safety bolt comprising an element having a shank with an axis and an unthreaded portion, the element having a first headed end and a second threaded end, an axial passage opening onto said second end, a laterally extending passage opening onto the shank and intersecting the axial passage, a dog slideably mounted between extended and retracted positions in said laterally extending passage whereby the dog extends beyond the maximum diameter of the shank in the extended position and retracts entirely within said shank in the retracted position, said dog including a planar restraint surface which lies normal to the said axis and faces the headed end, whereby it is adapted to abut the back side of a body into which the shank is inserted, a retraction surface facing toward the threaded end and sloping inwardly toward it, both of said surfaces being adapted to project beyond the radius of the unthreaded portion of the shank, whereby the restraint surface, when extended, prevents the removal of the bolt by a force exerted in shear and the retraction surface is adapted to engage the said body in order for the dog to be retracted into the bolt while the shank is being pressed into a hole in the body, the dog fully occupying the laterally extending passage in cross section to create such shear relationship, said dog including a ratchet face and a sloping retraction face, and a cam member movable in said axial passage and reactive with said dog to retract the same, bias means forcing the dog toward its extended position, and a nut threadable onto the threaded end having a plurality of ratchet faces in a counterbore, whereby tightening the nut onto the threads causes the dog to ratchet along the ratchet faces of the nut, and the ratchet faces to engage and resist unthreading of the nut from the bolt.

Claim 9

A combination according to claim 6 in which said dog and cam member each has a camming surface mutually reactive to retract the dog.

Claim 10

A combination according to claim 7 in which the cam member is axially movable, and in which the camming surfaces are slanted relative to said axis.

Claim 11

A combination according to claim 7 in which the cam member is rotatable, and in which at least one of the cam surfaces has a plurality of regions at different radial spacings from the axis.