Keyed adapter sleeve

In an internal combustion engine having an engine driven shaft with a tapered surface portion, and a shaft supported wheel for rotatably supporting a portion of the engine ignition system, an improved arrangement for coupling the shaft and wheel at a selectable relative angular orientation to determine the engine ignition timing comprising:

• a wheel hub integral with the wheel and having a tapered central opening;
• at least one keyway in the shaft tapered surface;
• at least one keyway in the wheel hub tapered central opening;
• and
• key means effective only when the hub and shaft are joined with their respective tapers in spaced alignment to join a hub keyway and a shaft keyway locking the wheel to the shaft in any selected one of a plurality of relative angular positions;
• the shaft tapered surface and the wheel hub tapered opening each including but a single keyway, the key means comprising a plurality of differing keys any one of which may join the hub keyway and the shaft keyway and each of which provides a different relative angular orientation between the wheel and the shaft with each key comprising a generally frusto-conical sleeve having an outer protuberance for engaging the wheel hub keyway and an inner protuberance for engaging the shaft keyway.

In an internal combustion engine having an engine driven shaft with a tapered surface portion, and a shaft supported wheel for rotatably supporting a portion of the engine ignition system, an improved arrangement for coupling the shaft and wheel at a selectable relative angular orientation to determine the engine ignition timing comprising:

• a wheel hub integral with the wheel and having a tapered central opening;
• at least one keyway in the shaft tapered surface;
• at least one keyway in the wheel hub tapered central opening;
• and
• key means effective only when the hub and shaft are joined with their respective tapers in spaced alignment to join a hub keyway and a shaft keyway locking the wheel to the shaft in any selected one of a plurality of relative angular positions;
• the key means comprising a generally frusto-conical sleeve having an outer protuberance for engaging the wheel hub keyway and an inner protuberance for engaging the shaft keyway, the spacing between the inner and outer protuberances determining the particular selected one of the plurality of relative angular positions.

In an internal combustion engine having an engine driven shaft with a tapered surface portion, and a shaft supported wheel for rotatably supporting a portion of the engine ignition system, an improved arrangement for coupling the shaft and wheel at a selectable relative angular orientation to determine the engine ignition timing comprising:

• a wheel hub integral with the wheel and having a tapered central opening;
• at least one keyway in the shaft tapered surface;
• at least one keyway in the wheel hub tapered central opening, the shaft keyway and the wheel hub keyway each being of a generally uniform depth relative to their respective tapered surface;
• and
• key means effective only when the hub and shaft are joined with their respective tapers in spaced alignment to join a hub keyway and a shaft keyway locking the wheel to the shaft in any selected one of a plurality of relative angular positions.

The method of presetting the ignition timing of an internal combustion engine having a rotatable shaft and a wheel supported on the shaft for rotation therewith wherein the wheel is a standardized flywheel designed to fit a number of different engines including engines of at least two different sizes of rotatable shafts the largest of which fits the flywheel inner hub and wherein the engine ignition system includes a relatively fixed portion supported by the engine and a movable portion sup ported on the wheel for rotation therewith, the method comprising the steps of:

• providing a slot in the shaft surface extending generally in the direction of the axis of rotation of the shaft;
• providing a slot in the wheel along an inner hub thereof;
• selecting one of a plurality of spacer keys having differing offset amounts, the step of selecting including choosing a spacer key of the appropriate offset amount having a dimension to provide a uniform separation just sufficient to compensate for the difference in size between the largest size shaft and the particular shaft to which the wheel is to be assembled;
• assembling the wheel to the shaft with the selected spacer key intermediate the wheel and shaft forming a generally uniform separation therebetween by moving the larger open end of the wheel inner hub toward the smaller outer end of a tapered portion of the shaft until the selected spacer key firmly engages both the shaft and the inner hub, and with one part of the selected spacer key occupying the shaft slot and another part of the selected spacer key occupying the wheel slot to thereby fix the angular relationship between the shaft and wheel at the angular offset determined by the particular spacer key selected.