Linotype mechanism

by Alvin Garfield Swank; Raymond Means

To Remove a Mouthpiece

When it is necessary to remove a mouthpiece for cleaning out the throat of the crucible, mark a line on the face of the crucible to align with the first hole on the right end of the mouthpiece. When replacing the mouthpiece the line will be your guide. By so adjusting there will be a full hole on each end of the slug when casting the different lengths, with the exception of half-pica measures. A hole on the adjustable or left end being partly covered by the liner in the mold would cause no trouble. If part of the first hole should be covered by the constant liner, the first letter on the right end of the slug would be blurred, or would not cast sharply, because the metal cools quickly on the ends of the mold, and a full, free flow is necessary.

The mouthpiece should always be removed when the metal is hot. If removed when cold there would be danger of breaking the pot crucible.

When removing the wedge style mouthpiece, place the vise in second position, lift out the mold slide, place a block of wood between the right side of the pot jacket and the slideway, drive the mouthpiece toward the keyboard, using a piece of brass as a drift. The above operation is necessary to loosen the wedge. The instant the mouthpiece moves, the wedge will become loose and can be lifted out.

Another method of removal is to grip the left-hand end of the gib with a pair of pliers, pulling the end of the gib forward and wrapping it around the pliers, prying against a piece of brass rule placed along the face of the mouthpiece. Care must be used in this method to hold the pliers at such an angle that the lip of the crucible will not be damaged while removing the gib.

Always have a new gib on hand before removing a mouthpiece, for it is difficult to use an old one in replacing a mouthpiece.

In replacing an old mouthpiece, extreme care must be taken to see that it is perfectly clean and straight. Clean the mouthpiece thoroughly and with a straight-edge test the mouthpiece to see that it is straight. If not, straighten it, being careful not to damage. This need not be done with a new mouthpiece.

Before placing the mouthpiece in the crucible, remove the left-hand vise locking stud nut and pull out the stud. Be careful not to lose the small brass washer which is on the stud. The removal of the stud permits the sliding in of the mouthpiece easily. The lips and the slot of the crucible, which are the seat for the mouthpiece, must be entirely free from all dirt and dross or the mouthpiece can not seat properly.

It is best to fit a mouthpiece to its seat by placing a very thin coating of fine emery and oil (fine valve grinding compound is good) on the back and top part of the mouthpiece. This method cleans the seat of all the accumulated dross and dirt. Place the mouthpiece in position in the pot so the top of mouthpiece is against the top seat and move back and forth, bearing lightly against the mouthpiece, until the high spots are ground down, so as to have the seat straight. When doing this, care must be taken not to get the paste on any other part of the machine, as it might cause trouble. The metal should be at casting temperature while fitting a mouthpiece. To hold the mouthpiece for this operation, procure a piece of wood furniture the same width and length of the mouthpiece, fasten this to the mouthpiece by driving a headless brad in each end of the wood directly in line with the last hole on each end of the mouthpiece. By placing the wood on the mouthpiece the brads pass through the two holes and make a very serviceable holder.

After fitting the mouthpiece, thoroughly clean all parts of the crucible lip, slot, and mouthpiece. The least particle of grit may cause trouble.

Fit the gib by dressing it, so that it will drive far enough to the right to make a tight fit. Cover the top and bottom with a thin coating of red lead and oil. Place the mouthpiece in position, the first hole in line with the mark on the crucible. Insert the wedge in the lower side and push it in as far as possible with a pair of pliers. Then drive in the gib so as to secure the mouthpiece firmly. Be careful that the mouthpiece does not move as the gib is being driven in. Lay a brass rule against the whole length of the gib and tap lightly with a hammer to firmly locate the gib on the seat, and at the same time, bring the outer edge of the gib slightly below the face of the mouthpiece.

After driving the mouthpiece to its proper position see that the ends are not burred; if so, file them off, as they might prevent the mouthpiece from locking up properly against the mold, and cause a back squirt.

The screw mouthpiece is held to the crucible by 13 screws. The screw holes in the mouthpiece are counter-sunk so the heads of these screws will not extend beyond the face of the mouthpiece.

To remove the screw style mouthpiece from the crucible, use the pot mouth screw loosener obtainable from the Linotype Company. Fit the loosener in the groove of the screw and tap the head with a hammer. As the screws will be tight, due to the heat and dross, this tapping will loosen them without damaging the screw heads. The screws can then be removed with a screw-driver.

Some features of the new mouthpiece are: There is no danger of breaking the lips of the crucible by driving the wedge in too far; it also eliminates the possibilities of battering the ends of the mouthpiece, as with the wedge style; leaking around the mouthpiece and improper setting when taken off and replaced is less likely to occur.

Due to the width of the face, one mouthpiece is sufficient for a slug of any size. This eliminates the necessity for a special mouthpiece for display, which was necessary with the older models.

Before replacing a screw mouthpiece be sure to thoroughly clean the surface of the crucible and the back of the mouthpiece of all dirt and dross. Place a thin coating of red lead and oil on the back of the mouthpiece and place it in position. Tighten the screws gradually, beginning at the ends and working toward the center.