Patent GB-190422879-A (GB)
Title: Improved Mechanical Movement for Converting Rotary into Reciprocating Motion
Inventor: JOHNSTON ROBERT TAYLOR
Filed: 1904-10-24
Granted: 1904-12-01
Abstract: 22,879. Johnston, R. T. Oct. 24. Cylinder machines with plane printing- surfaces.-In a mechanical movement, especially adapted for reciprocating the bed of a printing-press, a complete reciprocation of one element is effected during two revolutions of a crank element. In the arrangement shown in Figs. 1 and 3, parallel racks, mounted on a frame secured to the reciprocating bed 6, are adapted to be alternately engaged by a wheel 52 fixed to a shaft 53 journalled in an eccentric bushing 54. The driving- shaft 15 carries a pinion 51 in gear with the wheel 52, and also a pinion 50 gearing with a wheel 41, which carries a crank-pin 43 engaging a block 42 working in a slot in a reciprocating yoke 31. A rack 32 on the yoke gears with a wheel 33, loosely mounted on the shaft 15, such wheel being arranged to engage, at one end of the travel, a rack 12 fixed to the bed 6 for the purpose of reversing the same. A toothed flange 56 on the bushing 54 engages teeth on the end of a lever 57, which is operated by a yoke 61, provided with rollers in engagement with a cam 80. A block 62 on the cam shaft slides in the fork of the yoke. A pinion 70 on the shaft of the wheel 41 engages a wheel 71 on the cam sbaft. The motion of the yoke imparts an oscillating movement to the bushing 54 so as to bring the wheel 52 alternately into gear with each of the racks. To reverse the direction of motion of the bed at the other end of the travel, the bed is directly connected to an arm 30 of the reciprocating yoke 31 by a pin 88 adapted to engage a hole 85 in the arm. The pin is mounted in a bracket carried by the bed, and is connected to arms 89,90 carrying rollers adapted to engage stationary cams or projections 93, 94 carried by the frame. The pin is retained, normally, in a retracted position by a spring, and is actuated to lock the bed to the yoke by the engagement of the arms 89, 90 with the cams 93, 94. In operation, the bed is moved in one direction during one half a revolution of the crank wheel 41 and is then slowed down, brought to rest, and reversed during the second halfrevolution, due to the action of the crank working in the yoke 31 and the connections comprising the racks. 32, 12 and the wheel 33 ; during the third half-revolution, the bed is moved in the reverse direction, and it is then reversed during the last half-revolution, by the direct connection between the bed and the yoke. In a modification, the direct connection of the yoke and bed is dispensed with, and the reversal is effected by another wheel, gearing with the wheel 33 and with a rack similar to the rack 12 but at the opposite end of the bed. In another modification, shown in Fig. 10, the reversal of the bed at one end of the travel is obtained by locking the yoke 31 to the bed by a cam-latch 102, the crank element then effecting the reversal. Teeth on the arm 30 of the yoke actuate, through a pinion 109, another arm 106 carrying a slider 107 similar to the yoke 31 ; this slider is locked to the bed by a cam -latch 108 for the purpose of effecting the reversal of the bed at the other end of the travel.