| 摘要 |
There is provided a lift cam mechanism for an electronic parts-mounting apparatus including a vertical shaft and at least one mounting head arranged around the vertical shaft. The lift cam mechanism operates to lift and lower an associated one of the at least one mounting head as each mounting head is moved about the vertical shaft. A cylindrical cam is concentrically disposed with respect to the vertical shaft. The cylindrical cam has a protruding portion formed on a peripheral surface thereof in a manner such that the protruding portion has a generally annular shape and provides upper and lower cam surfaces. A pair of upper and lower cam followers are arranged respectively on the upper and lower cam surfaces of the protruding portion in a manner such that the pair of upper and lower cam followers sandwich the protruding portion therebetween in a manner rollable thereon. One end of the support member has one of the pair of upper and lower cam followers fitted therethrough and the other end of the same has the associated one of the at least one mounting head connected thereto. One end of the leaf spring is fixed to the support member and the other end of the same has the other of the pair of upper and lower cam followers fitted therethrough, for urging the other of the pair of upper and lower cam followers toward the protruding portion of the cylindrical cam. |
