A lock mechanism configured to be changeable between locked and unlocked conditions responsive to engagement of a proper key therewith,
- wherein the proper key includes
- a generally cylindrical shank, wherein the shank includes an outer cylindrical surface,
- wherein the outer cylindrical surface includes an arrangement of decoding elements, wherein the arrangement of decoding elements corresponds to the lock mechanism, and wherein the decoding elements include a plurality of encoding recesses,
- wherein the lock mechanism is configured to allow the shank of the proper key to be removed from engagement with the lock mechanism only in one particular angular position of the shank,
- the lock mechanism comprising:
- a cylindrical inner sleeve, wherein the inner sleeve includes a cylinder bore that extends along a central cylinder axis,
- a cylindrical outer sleeve,
- wherein the outer sleeve is in adjacent concentric relation about the cylinder axis with the inner sleeve,
- wherein the inner sleeve and the outer sleeve are relatively rotatably movable with respect to one another,
- a plurality of channels,
- wherein each of the plurality of channels extends radially with respect to the cylinder axis,
- wherein each of the plurality of channels extends in both the inner and the outer sleeve,
- wherein a plurality of channels extend in a plurality of axially spaced radial rows,
- wherein each radial row extends in a plane perpendicular of the cylinder axis,
- wherein each of the plurality of radial rows includes a plurality of channels, wherein each channel in a radial row is angularly spaced from each immediately angularly adjacent channel,
- and wherein each channel in each radial row is axially aligned in an axial row with a corresponding channel in each of the other radial rows of channels,
- at least one additional radial row of channels, wherein the at least one additional radial row of channels is axially disposed from at least one radial row of channels of the plurality of radial rows,
- wherein the at least one additional radial row includes a plurality of channels, each of which channels in the at least one additional radial row extend radially relative to the cylinder axis and are aligned in an axial row with channels in each of the plurality of radial rows of channels, with the exception that one channel that would otherwise cause all the channels of the at least one additional row to correspond with all the channels in the plurality of other radial rows, is not present in the at least one additional radial row,
- a plurality of pins, wherein each pin extends in and is radially movable with respect to a respective channel,
- wherein each pin includes two separable portions,
- wherein the two portions are separable from one another at a division line
- wherein the lock mechanism is configured so that when no key or an improper key is in the cylinder bore, at least some portions of the pins extend in the channels radially intermediate of the inner and outer sleeves such that the inner and outer sleeves are not relatively rotatably movable with respect to one another,
- and wherein when the shank of the proper key is in the cylinder bore, the encoding recesses are operative to cause the division lines of all the pins to be positioned generally radially intermediate of the inner sleeve and the outer sleeve, wherein the sleeves are relatively radially movable with respect to one another,
- and wherein the shank of the proper key is disengageable from the cylinder bore only in the one particular angular position in which all of the plurality of channels in the inner and outer sleeves in all of the radial rows are in radial alignment.