GB526257A - Improvements in bed motions particularly for printing presses - Google Patents

Abstract

526,257. Printing - machines. AMERICAN TYPE FOUNDERS, Inc. March 10, 1939, No. 7866. Convention date, July 7, 1938. [Class 100 (ii)] Bed-reciprocating apparatus.-In a bed-reciprocating apparatus which is especially applicable to printing- machines, the bed is reciprocated by a compound travelling gear 67, Fig. 1, carried by a crosshead 60 which is reciprocated on guides 62, 64 by means of a crank operated by variable planetary gearing which is so constructed that the bed moves during its printing stroke at a substantially constant speed but is returned at a variable and higher speed. The mechanism is similar to that described in Specification 526,256, but the gear ratios of the. gears of the planetary gearing are different, and the compound travelling gear multiplies the movement of the crosshead by a larger ratio. The crosshead 60 is reciprocated by a crank-pin 40 on a planetary gear 36 which is carried by a crank 32 to rotate around a sun wheel 42 free upon the main driving shaft 26 which carries the crank 32. The sun wheel is given an oscillating motion by a crank, driven from the main drive gear 24, which oscillates the rock shaft 44 connected to the sun-wheel. The compound gear 67 has one pinion 69 in engagement with teeth 70 on the guide rod 62, and a further pinion 68 engaging a rack 16 on the bed, the bed having a motion equal to 2 2/3 of that of the crosshead. The rod 62 can be finely adjusted by a screw to vary the setting of the gear 62 at the commencement of the printing operation. The sun-wheel may be external to the planet gear, and the planet gear in this case is the diameter of the sun-wheel. The path of the driving-crank is that of a modified prolate epitrochoid in one case, and a modified prolate hypotrochoid in the other. Specification 476,239 also is referred to.