Patent ID: 8430000

Claim:
A cam indexer, comprising: a driving assembly; a driving plate driven by the driving assembly, the driving plate defining an arc-groove on a periphery of the driving plate and a cam surface at a bottom of the arc-groove, the driving plate further comprising a receiving end and a resisting end positioned at opposite ends of the cam surface, a distance between the receiving end and a center of the driving plate being less than a distance between the resisting end and the center of the driving plate; a multi-task dial defining a plurality of positioning grooves along a periphery of the multi-task dial, an angle subtended at a center of the multi-task dial by every adjacent two of the plurality of positioning grooves being equal to an angle subtended at a center of the driving plate by the receiving end and the resisting end; a latching assembly fixed to the driving plate and elastically engaging in a first one of the plurality of positioning grooves, a positioning assembly elastically engaging in a second one of the plurality of positioning grooves and resisting on the receiving end of the driving plate, the first one and the second one of the plurality of positioning grooves are separated from each other by at least two of the plurality of positioning grooves, wherein the latching assembly is adapted to detach from the first one of the plurality of positioning grooves when the driving plate rotates toward the positioning assembly along a first direction, such that when the resisting end of the driving plate reaches the positing assembly and resists the positioning assembly to slide out of the second one of the plurality of positioning grooves, the latching assembly synchronously engages into one of the plurality of positioning grooves next to the first one of the plurality of the position grooves; and when the driving assembly drives the driving plate to rotate along a second direction opposite to the first direction, the latching assembly is adapted to drive the multi-task dial to rotate along the second direction until the positioning assembly reaches and engages into one of the plurality of positioning grooves next to the second one of the plurality of positioning grooves.