Drive spindle for tape reels

Claim 2

A drive spindle for internally ridged winding reels, comprising: a shaft member; at least two ridge-forming portions on the outer periphery of said member, each extending radially outward substantially the same distance from the axis thereof; and curved cam surfaces extending between and circumferentially bridging said ridge portions along a substantial portion of their length.

Claim 3

The drive spindle of claim 1, wherein said shaft member is tapered along at least a portion of its length to form an insertion end of reduced diametral proportions.

Claim 4

The drive spindle of claim 2, wherein said shaft member is tapered along a curve.

Claim 5

The drive spindle of claim 1, wherein said ridge portions converge toward one end of said shaft member.

Claim 6

The drive spindle of claim 4, wherein said ridge portions follow a curve as they converge.

Claim 7

The drive spindle of claim 1, wherein said cam surfaces are circumferentially curved between said ridge portions.

Claim 8

The drive spindle of claim 6, wherein each of said cam surfaces is curved along a substantially constant radius in a plane transverselY intersecting said shaft, said cam surfaces each being circumferentially circular in cross section.

Claim 9

The drive spindle of claim 7, wherein the radius of curvature of said cam surfaces is greater than the radially outward projection of said ridge portions from the axis of said shaft at corresponding points along the length of the shaft.

Claim 10

The drive spindle of claim 7, wherein the curvature of said cam surfaces is such that each has a different center of curvature.

Claim 11

The drive spindle of claim 6, wherein said shaft member is tapered along at least a portion of its length to form an insertion end of reduced diametral proportions.

Claim 12

The drive spindle of claim 6, wherein said cam surfaces are double-curved at least in part, each having said circumferential curve and also having a longitudinal curve in a plane intersecting the axis of said shaft along its length.

Claim 13

The drive spindle of claim 11, wherein said cam surfaces are mutually convergent along the length of said shaft and form a shaft end extremity of reduced diametral proportions.

Claim 14

The drive spindle of claim 12, wherein said ridge portions are mutually convergent along said shaft and toward the said end extremity thereof.

Claim 15

The drive spindle of claim 13, wherein each of said cam surfaces is curved along a substantially constant radius in a plane transversely intersecting said shaft, said cam surfaces each being circumferentially circular in cross section.

Claim 16

The drive spindle of claim 14, wherein the radius of curvature of said cam surfaces is greater than the radially outward projection of said ridge portions from the axis of said shaft at corresponding points along the length of the shaft.

Claim 17

The drive spindle of claim 15, including at least three of said ridge-forming portions, each equidistant from the two laterally closest to it around the circumferential periphery of said shaft.

Claim 18

A drive spindle for internally ridged winding reels, comprising: a shaft member; at least three ridge-forming portions on the outer periphery of said member, each extending radially outward substantially the same distance from the axis of said shaft; and cam surfaces extending between and circumferentially bridging said ridge portions along a substantial portion of their length; said cam surfaces being mutually convergent along at least a portion of the length of said shaft means, in a direction toward a free end thereof.

Claim 19

A drive spindle for internally ridged winding reels, comprising: a shaft member; at least three ridge-forming portions on the outer periphery of said member, each extending radially outward substantially the same distance from the axis of said shaft; and cam surfaces extending between and circumferentially bridging said ridge portions along a substantial portion of their length; said cam surfaces being mutually convergent along at least a portion of the length of said shaft means, in a direction toward a free end thereof.

Claim 20

In combination: a cassette-type magnetic tape cartridge having internally ridged winding spool means, and a drive spindle for insertion into and rotation of such spool means; said drive spindle having a plurality of adjacent axially elongated side surfaces which converge circumferentially to form spaced longitudinal ridges on said spindle and which converge longitudinally to taper said spindle; said ridges having a size and being spaced such that they fit between certain adjacent pairs of said spool means ridges; and said side surfaces having a size and shape such that they contact at least portions of the spool means ridges between which said spindle ridges fit, such that said spindle when inserted through said cassette spool means will drive the same rotationally by the contacting spool means ridges and spindle side surfaces.

Claim 21

In combination: a cassette-type magnetic tape cartridge having internally ridged winding spool means, and a drive spindle for insertion into and rotation of such spool means; said drive spindle having a plurality of adjacent axially elongated side surfaces which converge circumferentially to form spaced longitudinal ridges on said spindle and which converge longitudinally to taper said spindle; said ridges having a size and being spaced such that they fit between certain adjacent pairs of said spool means ridges; and said side surfaces having a size and shape such that they contact at least portions of the spool means ridges between which said spindle ridges fit, such that said spindle when inserted through said cassette spool means will drive the same rotationally by the contacting spool means ridges and spindle side surfaces.