Expandable pulley
View Patent ↗An expandable pulley. The expandable pulley comprises a plurality of belt blocks arranged about an axis of rotation. Each belt block bears upon a radial surface extending normally to the axis of rotation. Another surface of each belt block bears upon a conical member surface which is moveable coaxially with the axis of rotation. A spring bears upon the conical member which urges the conical member in an axial direction, which in turn urges the belt blocks radially outward to compensate for a belt length change and to maintain a belt tension. An elastic member holds the belt blocks in contact with the conical member.
1. An expandable pulley comprising:
a radial surface extending normally with respect to an axis A—A;
a conical surface moveable relative to the radail surface;
a plurality of blocks arranged in a substantially circular form, a block first surface slidingly engaged with the radial surface and a block second surface slidingly engaged with the conical surface;
an elastic member engaged with each block whereby each block is held in contact with the conical surface; and
a single spring member co-axial with axis A—A axially urging the conical member whereby each block is radially moveable upon an axial movement of the conical member.
2. The pulley as in claim 1 , wherein each block further comprises a belt engaging surface.
3. The pulley as in claim 1 , further comprising a second radial surface disposed substantially parallel to the radial surface and each block being engagable with said second radial surface.
4. The pulley as in claim 1 further comprising;
a bearing; and
the bearing engagable with a fastener whereby the pulley rotates about the fastener.
5. An expandable pulley comprising:
a radially extending surface;
a conical surface moveable relative to the radially extending surface;
a plurality of blocks arranged in a substantially circular form, a block first surface slidingly engaged with the radially extending surface and a block second surface slidingly engaged with the conical surface;
a single biasing member co-axial with axis A—A axially urging the conical member whereby each block is radially moveable upon an axial movement of the conical member; and
a removable member for temporarily retaining the conical surface in a predetermined position with respect to the radially extending surface.
6. The expandable pulley as in claim 5 further comprising;
an elastic member engaged with each block whereby each block is held in contact with the conical surface.