Arrangement comprising a shaft, a hub mounted on the shaft by means of an elastically expansible clamping member, and an expansion device for expanding the clamping member

A clamping member, comprising:

• a symmetrical, planar, annular member defining an axis of symmetry, said annular member including
• at least three inwardly directed clamping zones circumferentially equispaced and extending in the plane defined by said annular member,
• an application zone associated with each of said clamping zones for receiving an expansion device,
• the annular member being (i) substantially non-deformable in circumferential areas each including a said clamping zone and (ii) elastically deformable in circumferential regions between said circumferential areas for biasing each of said application zones in the radial direction relative to the axis of symmetry, the application zones being located in said elastically deformable zones so that inward movement in the radial direction of said application zones by the expansion device causes radial outward movement of said clamping zones.

An arrangement, comprising:

• a) a shaft having an axis of rotation;
• b) a part having a hub mounted on said shaft and including a tubular portion, said tubular portion being coaxial with said shaft and elastically deformable in radial directions;
• and
• c) an annular, planar clamping member for clamping the tubular portion on said shaft, said clamping member being clamped on said shaft and including
• at least three inwardly directed coplanar clamping zones equispaced in the circumferential direction of said clamping member for clamping said tubular portion, said clamping zones extending perpendicular to said shaft axis of rotation, and
• an application zone associated with each of said clamping zones for receiving an associated mandril of an expansion device,
• the clamping member being (i) substantially non-deformable in circumferential areas each including a said application zone and (ii) elastically deformable in circumferential regions between said circumferential areas for biasing each of said application zones in the radial direction relative to said axis of rotation, and
• said part mounted on said shaft further including passages, each associated with a said application zone, extending in the axial direction of said shaft and through which a mandril of the expansion device is insertable to engage a respective application zone.

A rotary scanning device for scanning a magnetic tape, comprising:

• a) a stationary drum section;
• b) a rotatable shaft having an axis of rotation;
• c) a rotary drum section mounted on said rotatable shaft and rotatable relative to said stationary drum section, said rotary drum section having a hub mounted on said shaft and including a tubular portion coaxial with said shaft and elastically deformable in radial directions;
• and
• d) an annular, planar clamping member for clamping the tubular portion on said shaft, said clamping member being clamped on said shaft and including
• at least three inwardly directed coplanar clamping zones equispaced in the circumferential direction of said clamping member for clamping said tubular portion, said clamping zones extending perpendicular to said shaft axis of rotation, and
• an application zone associated with each of said clamping zones for receiving an associated mandril of an expansion device,
• the clamping member being (i) substantially non-deformable in circumferential areas each including a said application zone and (ii) elastically deformable in circumferential regions between said circumferential areas for biasing each of said application zones in the radial direction relative to said axis of rotation, and
• said rotary drum further including passages, each associated with a said application zone, extending in the axial direction of said shaft and through which a mandril of the expansion device is insertable to engage a respective application zone of said clamping member.

A rotary scanning device for scanning a magnetic tape, comprising:

• a) a stationary drum section;
• b) a rotatable shaft having an axis of rotation;
• c) a rotary drum section mounted on said rotatable shaft and rotatable relative to said stationary drum section, said rotary drum section having a hub mounted on said shaft, said hub including a substantially non-deformable central portion and first and second tubular portions projecting from said central portion in opposite axial directions, said tubular portions each being coaxial with said shaft and elastically deformable in radial directions;
• and
• d) first and second annular, planar clamping members each for clamping a respective said tubular portion on said shaft, each clamping member being clamped on the respective tubular portion and including
• at least three inwardly directed coplanar clamping zones equispaced in the circumferential direction of said clamping member for clamping the respective said tubular portion, said clamping zones extending perpendicular to said shaft axis of rotation, and
• an application zone associated with each of said clamping zones for receiving an associated mandril of an expansion device,
• the clamping member being (i) substantially non-deformable in circumferential areas each including a said application zone and (ii) elastically deformable in circumferential regions between said circumferential areas for biasing each of said application zones in the radial direction relative to said axis of rotation, and
• said first clamping member exerting a first clamping force on said first tubular portion and said second clamping member exerting a second, substantially different clamping force on said second tubular portion, said first clamping force being selected to provide radial positioning of said rotary drum section on said shaft while permitting axial movement along said shaft and said second clamping force being selected to axially fix said rotary drum section on said shaft.