Indexing drive having a cam-positioning mechanism

An indexing drive comprising:

• a housing having upper and lower parts, said upper part having opposed first and second side walls, and said lower part having opposed third and fourth side walls;
• an output shaft rotatably supported in said upper part of the housing via output-shaft bearings that are held in two bearing holders secured to said opposed first and second side walls, respectively, of said housing, said output shaft including a positioning reference surface outside of said housing, said reference surface being perpendicular to the axis of said shaft, and a follower wheel mounted on said shaft between said output-shaft bearings, said follower wheel having a plurality of rotatable roller followers disposed on and along an outer periphery thereof;
• a cam shaft rotatably supported in said lower part of the housing via cam bearings that are held in two cam-bearing holders secured to said opposed third and fourth side walls, respectively, of said housing, said third and fourth walls extending substantially at right angles to said first and second side walls in such a way that said cam shaft is disposed substantially at right angles to said output shaft;
• and
• a cam mounted on said cam shaft between said cam-bearing holders, said cam shaft being mounted relative to said output shaft so that said cam is engageable with respective ones of said roller followers of said follower wheel,
• wherein said two cam-bearing holders are bolted to said third and fourth side walls of said housing in such a way that respective positions of said cam-bearing holders are adjustable within a plane perpendicular to an axial direction of said cam shaft along said third and fourth side walls, each of said cam-bearing holders having first peripheral portions defining a first reference surface engageable with co-planar surfaces for positioning said cam-bearing holder relative to said positioning reference surface of said output shaft in an axial direction of said output shaft and second peripheral portions defining a second reference surface engageable with co-planar surfaces for positioning said cam-bearing holder in a direction orthogonal to the axial direction of said output shaft.