Work indexing mechanism with a height adjustment for a pair of transfer bars

An apparatus wherein a pair of transfer bars, extending horizontally in parallel spaced relation to each other, are reciprocated longitudinally and moved up and down and toward and away from each other for transporting work through a succession of processing stations, a mechanism for imparting the up-and-down motion to the pair of transfer bars, comprising:

• (a) lift carrier means for carrying the transfer bars to as to allow their longitudinal reciprocation and movement toward and away from each other;
• (b) a lift cam mechanism;
• (c) a rack-and-pinion linkage between the lift cam mechanism and the lift carrier means for moving the latter, and therefore the transfer bars, up and down in response to the operation of the lift cam mechanism;
• (d) a cylinder actuated height adjustment mechanism providing a variable length of connection between the lift cam mechanism and the rack-and-pinion linkage for adjustably varying the upper and lower limits between which the transfer bars are moved up and down and wherein the apparatus further includes means for yieldably urging the transfer bars upwardly, and wherein the cylinder actuated height adjustment mechanism includes:
• (i) a first link operatively connected at one end to the lift cam mechanism thereby to be reciprocated longitudinally,
• (ii) an abutment housing rotatably engaged with another end of the first link and constrained to joint reciprocation therewith, the abutment housing generally extending away from the first link in co-linear relation thereto;
• (iii) a hollow, multiple abutment member fixedly mounted in the abutment housing and providing a plurality of abutments in various angular positions about the axis of rotation of the abutment housing relative to the first link and at various distances from the first link;
• (iv) a second link slidably extending through the multiple abutment member for both relative rotation and lonitudinal displacement and coupled at one end to the rack-and-pinion linkage, the second link being longitudinally biased away from the first link by the yieldably urging means;
• (v) hook means on another end of the second link for selective engagement with the abutments of the multiple abutment member depending upon the angular position of the latter relative to the second link;
• and
• (vi) drive means acting on the abutment housing to vary the angular position of the multiple abutment member relative to the second link and said hook.