Stop-Cylinder Presses

Drive and Bed Motion ( for bottom cylinder feeders)
The drive of a stop-cylinder is effected by a motor driving a shaft situated at the fountain end of the machine. Near the centre of the shaft and fastened to it are two spur gears which run in mesh with two large driving gears. These large driving gears are joined by a crank pin to which one end of a connecting rod is attached. At the other end of the connecting rod, two smaller gears are attached by their centre axle and travel back and forth on two lower racks. These are called traverse racks. Above the traverse gears are two corresponding racks on the underside of the bed carriage. The traverse gears running in the upper and lower racks are the means of making the bed move back and forth. The best known of these presses was the Wharfedale, introduced by William Dawson and David Payne during the late 1850's in the Yorkshire town of Otley, U.K.

The Movement and Control of the Cylinder
The racks on the bed (topside), driving the loose and fixed gears cause the cylinder to revolve. The fixed gear, which has a flat on one side is also called the register gear. The loose gear is called the contact or starting gear. This gear revolves freely back and forth, independent of the cylinder until the impression lever is placed in the 'printing' position. Placing the impression lever in this position allows the cylinder catch, which is fastened to the loose gear, to drop behind the abutment ring on the cylinder thereby causing the cylinder to revolve. The impression lever in this position brings into action another mechanism which causes the feedboard to lift and the grippers to close prior to the cylinder turning. If the cylinder takes with a bump, the adjustment is made by moving the traverse rack in the right direction.
Control and Adjustment of the Push-Rod
To obtain positive operation of the cylinder together with accurate register it is essential to make sure that the impression cylinder is pushed "home" after every revolution. To test if the cylinder is pushing "home" place a strip of thin paper between the register stop and the lug on the brake wheel. Turn the flywheel until the pushrod cam roller is on the highest point of the pushrod cam. In this position the strip of paper should be firmly held in position. If it is not, the pushrod must be adjusted by means of the adjusting nuts near the cam roller. Care must be taken with this adjustment or undue wear will occur on the cam.
Cylinder Brake
This controls the cylinder at the completion of every revolution. If the brake is too loose the cylinder will bump after every turn, but if it is too tight the machine will slow down (labour) near the end of the printing stroke. The method of adjustment is to turn the flywheel until the brake cam roller is on the highest point of the brake cam. In this position the cylinder is almost home and the brake should be fully on. If it is not then adjust the tension by lengthening the brake rod by the adjusting nuts.
Duct Roller Setting
Turn the machine over until the duct roller is at its lowest point of travel. In this position the duct roller should firmly grip strips of thin paper placed between it and the ink table. If it does not, then the adjustment is made by moving the duct roller actuating rod in the slotted arc to the required position.
To set the duct roller to the duct cylinder, turn the machine over until the duct roller is in its highest position. In this position the duct roller should firmly grip strips of thin paper between it and the duct cylinder. If it does not, then adjust to its required position by lengthening or shortening the duct roller actuating nuts. This adjustment may be at either the top or bottom of the roller. Check and recheck all adjustments!

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