The linotype keyboard is power driven and mechanically operated, the operator merely touching the keybutton lightly to get a matrix. The keyboard and escapement mechanism consists of ninety-one mechanical units, or series of levers, escapements, and cams—one series for each key on the keyboard.
The keyboard consists of the frame; the keylevers, extending through the slots to the back of the keyboard frame; the keylever fulcrum rods, which are the pivot rods for the keylevers; the keybars, that groove into the rear end of the keylevers; the keybar banking bar, (fastened to the right- and left-hand keyboard posts), holding the keybars in place; and the keyboard locking bar. The various parts of the keyboard are held in their respective places by the keyboard frame.
Mounted on the top, at the rear of the keyboard, are the two cam yoke frames. The keyboard cam yoke frames contain the cams and the cam yokes, assembled; the cam yoke triggers; the cam stop strips; the hinge rods; the keyboard cam rubber roll shafts, with the pulleys or the gears and friction springs; and the rubber rolls, assembled. The frames are fastened to the keyboard posts by a screw at each end of the frame, which extends through the rubber roll shaft brackets. Both the frames are equipped with cover pans.
The keyboard action for releasing a matrix from the magazine is as follows: When the keybutton is depressed it lowers the outer end of the keylever, raising the back end. The keylever raises the keybar. The keybar raises the lower end of the trigger, causing the upper end to tilt. This allows the free end of the cam yoke to drop, causing the cam to engage the revolving rubber roll. The cam is revolved by the rubber roll, and as it reaches the high point it raises the free end of the cam yoke. This end of the cam yoke engages the keyrod and causes it to be raised. The keyrod operates the escapement mechanism in the magazine and releases the matrix.
Keyboard Parts
The keylevers extend through slots in the keyboard frame and are pivoted near their center by the fulcrum rods. The front end of the keylevers carry the keybuttons and the back ends fit into notches in the keybars.
The keybars are held in place on the back of the keyboard by the banking bar and the upper and lower keybar guides. The keybars have notches on the upper end into which the triggers set. Also there are notches into which the keylevers extend. These notches are cut at different points on each six keybars, to correspond with the point at which the keylever protrudes through the frame.
On the late model machines the keybars are made with notches so they will fit in any alternate position, each bar having three notches, any one of which will register with the keylever. In removing the bars for cleaning, always take them off in groups of six and keep them in order so that no difficulty will be experienced in replacing them. It is always better to replace each bar in its original place after having them off.
The keyboard locking bar extends across the back of the keyboard, just above a shoulder on the keybars. When this bar is forced down it prevents the keybar from being raised, thus locking the keyboard.