Devices for aligning racks and pinions for assembly, namely, testing instruments for the alignment of racks of rack and pinion gears for machines and rack and pinion drives for machines; mechanical devices and apparatus for adjusting the distance of toothed racks arranged behind one another, namely, testing instruments for the alignment of racks of rack and pinion gears for machines and rack and pinion drives for machines; mechanical devices for adjusting the backlash between gearing parts an...