Abstract: A locking apparatus for locking the rotational position of a fastener component which is rotatable about an axis relative to a structure. The locking apparatus includes a collar and a rigid arm. The collar is configured to engage with the fastener component such that relative rotation of the collar and the fastener component is substantially prevented. The arm has a first end configured to engage with the collar such that rotation of the collar relative to the first end is substantially prevented, and a second end configured to engage with the structure such that rotation of the arm relative to the structure is substantially prevented. The collar has an inner surface having a first finite order of rotational symmetry about the axis, and an outer surface having a second, larger, finite order of rotational symmetry about the axis.

Abstract: A locking apparatus for locking the rotational position of a fastener component which is rotatable about an axis relative to a structure. The locking apparatus includes a collar and a rigid arm. The collar is configured to engage with the fastener component such that relative rotation of the collar and the fastener component is substantially prevented. The arm has a first end configured to engage with the collar such that rotation of the collar relative to the first end is substantially prevented, and a second end configured to engage with the structure such that rotation of the arm relative to the structure is substantially prevented. The collar has an inner surface having a first finite order of rotational symmetry about the axis, and an outer surface having a second, larger, finite order of rotational symmetry about the axis.

Abstract: A plurality of staking die sets is provided, each adapted to crimp an iron fence rail onto a picket where the latter passes through an aperture in the former. Each die set comprises a staking die matching the cross sectional shape of the picket and adapted to embrace one half of the picket on one side of the rail. A corresponding anvil die opposes the staking die on the opposite side of the rail. Mechanically leveraged, powered jaws force the staking die toward the anvil and against the rail to squeeze the rail in the immediate vicinity of the picket, causing rail metal around the aperture to flow toward the picket, reducing the aperture until the picket becomes immobilized. A plurality of such jaws and dies, adjustably arrayed at selected spacings and coupled to a common power source, allows a single staking operation to affix simultaneously all pickets in a given length of rail.