set, cover the back of the mold with a thin coating of red lead; turn
the disk and mold until the mold passes the knife. If the knife is
adjusted properly, it should scrape the lead from the mold. It is
not always an easy matter to set a mold knife, taking considerable
patience and care because the knife must be set to thousandths of
an inch. Cast a slug and measure with the micrometers to make sure
the slug is trimmed to the proper height. When measuring the slug
for height with micrometers, use a slug 15 picas in length, or one
that fills half of the capacity of the mold. Have the regular letter
characters cast on the slug.
Metal will adhere to the bottom of the mold if the mold knife is not
sharp or properly adjusted. To keep a perfect lockup the bottom of
the mold must be kept clean. Mold knives can be resharpened, but
as they are shaped to set just so the edge of the knife touches
the mold and must not vary, for even .001 of an inch will spoil
the adjustment, they should be shipped to the nearest agency to be
resharpened.
Be sure the knife is at fault before starting to adjust it.
MOLD BANKING STRIPS
The mold banking strips are fastened on the vise, one above the
parallel knives and the other one below the bottom end of the knives.
These strips prevent the mold from coming in contact with the knives
and holds the disk rigid when ejecting the slug, assisting the knives
in trimming the slug parallel. The mold slide should advance the
proper distance so the mold will just bank against the banking strips
when forward for ejecting the slug.
KNIFE BLOCK
At the present time there are two styles of knife blocks in common
use, namely: The wedge adjustment block, which allows for a range
from 5 to 12 points, inclusive; and the universal knife block which
allows for a range from 5 to 36 points, inclusive. These blocks
are fastened to the vise frame by two hexagon head machine screws
and held rigid by four dowel pins. To remove the block it is only
necessary to take out the two machine screws and work the block out
of the dowel pin holes. A certain amount of care is necessary not to
drop the block or bend the pins.
TRIMMING KNIVES
The purpose of the trimming knives is to trim the slugs to the proper
size and the sides parallel.
The measurement of a type-founders point is .0138-⅓ of an inch. The
measurement of a linotype point is .014 of an inch.
The point unit now used on the matrices is the one used by the
type-founders. The linotype point is still being used when adjusting
the trimming knives. A 10-point slug, when trimmed correctly, should
measure .140 of an inch, or 10 times .014 of an inch.
The left-hand knife trims the overhang from the smooth side of the
slug and is held to the vise by two square head screws that pass
through the front, and is adjusted by two screws, at the top and
bottom of the knife block and bearing against the knife. This knife
should be adjusted to be in line with the left side of the mold; it
is only intended to remove the fins which form at the top of the
slug. It is not intended to remove metal from the smooth side of the
slug.
If the left-hand knife does not trim the overhang off the slug, it
will cause the slugs to be thicker at the top than at the bottom, and
be off their feet. This will cause trouble in the lockup of the form,
the columns having a tendency to raise up in the center.
Always loosen the two screws which hold the knife to the vise when
making any adjustment of the left-hand knife. Turning in on the
adjusting screws without loosening the two lock screws may cause the
knife to spring and trim the slugs more in the center than on the
ends.
The right-hand knife trims the slug to thickness and is held to
the slide bracket on the universal knife block, by two round head
screws. It is forced to the right against the adjusting screws by
two springs. The screws that hold the knife to the bracket should be
loose when moving the adjusting screws outward, as the spring should
force the knife against the adjusting screws in this movement. It
is not necessary to release the screws that hold the knife to the
bracket when turning the screws inward as the screws are forced
against the knife in this adjustment.
The screws in the sector are set to step from one point size to
another and should not be changed except when necessary to trim any
body size to a special thickness.
Beneath the bracket to which the knife is fastened are two spiral
springs that force the bracket and knob button against the sector
screws. Moving the lever operates the sector, and the screw coming
in contact with the button on the slide causes the knife to move in
or out one point or as many as the lever is moved. When casting a
10-point slug, have the pointer on figure 10.
After having the knives adjusted to trim one size slug, the knife
block is constructed so as to trim all others, by merely moving the
handle on the knife block. When changing the universal knife block,
be sure that one of the lever detent pins has entered the hole in the
sector.
To adjust the trimming knives, first set the right-hand knife by
turning the two adjusting screws that are in the knife block slide
bracket and touching the side of the knife, so it will trim the
ribs of a slug; then adjust the knife that trims the overhang from
the smooth side of the slug; then re-adjust the right-hand knife to
thickness and parallel. Do not attempt to adjust the knife that trims
the overhang from the smooth side of the slug unless the right-hand
knife is trimming the ribs.
WEDGE STYLE KNIFE BLOCK
The wedge style knife block is the old style quick-change block
and is held to the vise in the same manner as the universal block.
The left-hand knife is mounted and adjusted the same as with the
universal block. The right-hand knife is held to the block by two
shoulder screws which pass through the two friction springs and
washers from the front of the block. This assembly holds the knife
tight against the block, but permits the two strong springs to force
the knife against the wedge.
The wedge is operated by a small hand lever and is graduated from 5
to 12 points, inclusive. By pulling the lever up or down the wedge
moves and the knife follows the wedge.
KNIFE, RIGHT HAND, SPRING PLATE
There is a steel plate assembled in the right side of the knife block
which keeps the slugs upright as they travel through the knife block
into the chase. This plate is called the knife spring plate and is
held in place by two lugs at the back of the plate extending into
the base of the right-hand knife. It is forced toward the left by a
flat bronze spring, called the spring plate spring. There should be
just enough tension on this spring to force the plate up against the
outgoing slug with an even pressure so the slug will be held upright
as it is being pushed into the chase by the ejector blade. The flat
spring is so shaped that the ends fit behind rivet heads, to hold the
plate in place. If the spring becomes bent so it will not stay behind
the rivets, the lugs will work out of their seat and the gate will
obstruct the passageway of the slug. This will oftentimes smash the
face of the slugs.
FACTS AND SUGGESTIONS ABOUT TRIMMING KNIVES
The right-hand knife must be adjusted so that its edge is exactly
parallel with the left-hand knife in order to make the slug of equal
thickness throughout its entire length. The faces of the two knives
separate slightly toward the front of the machine, which allows the
slug to pass freely forward from the cutting edges. The right-hand
knife must be shaped so there is a cutting edge of about 1/64 of an
inch on the side that stands next to the slug. By having this edge
the “gouging” of the knife into the slug is prevented, and slugs are
trimmed to equal thickness at the top and bottom. This cutting edge
must never be more than 1/64 of an inch.
Always remember that the knives can be set to trim the slugs
perfectly from one point-size to another with accuracy, but it
requires patience, as the knives must be adjusted to a thousandth
part of an inch.
Keep the knife block and the knives clean. The seat of the knives
should also be clean. It will be impossible to get an accurate
adjustment if dirt or gum interferes with the movement of the knives.
The trimming knives should have exceedingly sharp or thin edges to
work satisfactorily. If the knives become very dull or the cutting
edge rounded or nicked, they should be taken off the machine and
reground. Send them to the nearest agency as they are equipped with
grinders and other fixtures to do this regrinding and maintain
the correct angles and shape of the knives. Always send both the
right-hand and left-hand knives, as they should be reground in pairs,
and the cutting edges should exactly match each other in order to
obtain good results.
Use a full measure slug when adjusting the trimming knives. Cast a
full line of capital letters on the slug and hold the matrices for
recast. Measure the slug on the ribs at the top and near the bottom.
The slug should measure the same at the top edge and near the bottom
if the knife which trims the smooth side is correctly set. The slug
should measure the same at the top edge of both ends if the knife
which trims the rib side of the slug is correctly set.
Before setting the trimming knives, make sure that the mold is
properly seated in the mold disk and that there is no metal between
the liners and the mold.
When the trimming knives become dull it is practically impossible to
set them to trim accurately. Even when they are set nearly accurate,
they will hold the adjustment only a short time.
Dull knives also cause trouble by making it difficult to eject the
slug. This will often cause the clutch to slip.
When a long slug measures thicker or thinner at the ends than in the
center, it is usually due to dull knives, but may be caused by the
knives being forced in a twist or strain by the adjusting screws or
some foreign substance behind the knives.
KNIFE WIPER
The knife wiper is a very important part of the Linotype. Its
function is to wipe the burrs or slug trimmings from the face of the
parallel knives after a slug is ejected. If the knife wiper is not
working, the face of the line of type will have an accumulation of
shavings from the previous line on it.
The knife wiper in use on all machines of very recent manufacture
is operated by a small roller, fastened to a bracket on the first
elevator slide, which comes in contact with a lever connected to the
knife wiper bar. When the elevator goes from normal to the lower, or
casting, position, the knife wiper bar is forced upward. On the upper
end of the knife wiper bar is a small brass wiper which is forced
upward with the bar. This wiper rubs against the trimming knives,
cleaning them of the metal shavings which may have lodged from the
previous slug trimmed.
There are no adjustments on this type of wiper, except to have the
brass lightly touching the knives.
OLD STYLE KNIFE WIPER
There are quite a number of the old style knife wipers still in use.
This knife wiper is operated by a latch rod on the first elevator
lever. This rod comes in contact with a latch on the knife wiper
bar, on its downward stroke, and pushes the bar upward by coming in
contact with the bottom of wiper bar on the upward stroke of the
first elevator lever. The wiper bar should be free to move up and
down in the guides, moving the brass wiper lightly over the face of
the trimming knives. On the upper part of the wiper bar are two pins
which prevent the bar from going too far below the knives and too
high above them. A flat spring riding over the top of the bar holds
it to the bottom of the guide so the brass wiper can operate properly.
The brass wiper is held to the bar with two flat head screws, and the
constant passing of the wiper over the face of the sharp knives soon
wears the wiper so it will break off. A new wiper must be applied or
the shavings will hang to the slugs.
Never have the wiper bearing too hard on the face of the knife as
the constant rubbing up and down will dull the trimming edge of the
knives and wear the wiper in a short time.
Keep the knife wiper in good working condition all the time and save
proofreader’s marks.
Do not forget that the knife wiper is operated by the first elevator
slide. Therefore anything that prevents the free action of the wiper
will interfere with the movement of the first elevator.
MOLD TURNING CAM, SQUARE BLOCK, AND PINION
The mold turning cam, known as cam No. 3, has attached to its side
the long and short gear segments which impart rotation to the mold
turning pinion and square block as the cam revolves. The square block
and pinion are found on the inside of the mold gear arm. The gear
segments on the mold turning cam turns the pinion, the pinion turns
the mold turning shaft, and the mold turning shaft turns the mold
disk, through the mold disk pinion which meshes with the mold disk.
The short segment turns the mold disk one-quarter of a revolution so
as to bring the mold disk into casting position. The long segment
turns the disk three-quarters of a revolution, bringing the mold
and disk in ejecting position. The mold disk makes one complete
revolution in one revolution of the cams.
When the disk makes one-quarter revolution, it is advanced so as
to lock the stud block on the vise with the studs on the mold
disk, and the slug is cast; the mold then is withdrawn and makes
a three-quarter revolution, advancing again and locking to eject
the slug. When the mold disk makes the quarter and three-quarter
revolutions, all lost motion must be taken up by the square block on
the pinion. If there is any lost motion, the studs on the mold disk
would not be parallel with the stud blocks on the vise so that they
could not enter them without coming in contact with the rim of the
stud block.
ADJUSTING SHOES
On the mold turning cam are two adjustable steel shoes for the
purpose of taking up the play between the shoes and the square block
when in the casting and ejecting position. These shoes are adjusted
by screwing in on the bushing screws that extend through the cam and
bank against the shoes. Each shoe is held in place by two machine
screws that extend through the bushing screw into the shoe. When
adjusting the shoes care must be taken to make them parallel. The
distance from the front end of each shoe to the outside of the cam
must be the same as it is from the back end of the shoe to the
outside of the cam. If these shoes are adjusted wider at the back
than at the front they act as wedges as they go down by the square
pinion, and may break the cam at the weakest point. If a shoe is
set too tight against the square pinion it will break the cam.
All that is necessary is to adjust them so as to take up the lost
motion between the shoes and the square pinion. It is better to use
a micrometer to measure the shoes to make sure they are parallel.
Allow a trifle lost motion between the square block and the shoes,
because it is better for them to have a little play than to be too
tight and perhaps break the cam.
The square block and pinion are held in position on the shaft by a
set screw, and there is no adjustment except to have this screw on
the top when the machine is in normal position. The screw passes
through the square block to the shaft and must enter the spot drilled
on the shaft for the point of the screw so as to hold the pinion
tight. On the two sides of the square block are two steel shoes,
which are held to it by screws. These shoes can be renewed when they
become worn.
MOLD DRIVING SHAFT FRICTION CLAMP
The object of the friction clamp is to prevent the mold disk from
vibrating when advancing to the casting or ejecting position, and is
found attached to the mold driving shaft and held by a pin in the
mold gear arm. The lost motion in several pinions from which the mold
disk gets its action, will cause the disk to vibrate when stopping
ready to advance on the vise stud blocks, unless it is held by the
clamp which acts as a brake.
When the mold disk has made the one-quarter and three-quarter
revolutions it must remain in that position, or the locking studs,
coming in contact with the rims of the stud block, would wear.
The friction clamp which overcomes the vibration is made in two
sections, with a leather lining, and connected to the mold turning
shaft. A spring, washer, and lock nut add to its construction. The
pin in the mold gear arm to which it is also connected prevents
it from turning with the shaft. Do not have more friction than
necessary, for if there is too much, the main clutch could not drive
the machine, as the strong friction on the clamp would overcome the
pull of the clutch spring.
RETIMING MOLD GEARS
There are various methods of retiming the gears of the mold disk
drive in case it is necessary to pull the disk forward while the
machine is out of normal.
One method is to observe the position of the mold turning segments.
Remember that the short segment causes the mold to revolve
one-quarter revolution, or from normal to casting position. The long
segment causes the mold to revolve three-quarters revolution, or from
casting to ejecting position. The mold disk turns counter-clockwise.
Place the gears in mesh so the punch marks on the gears register.
Lock the mold slide in position. The drive pinion makes one complete
revolution for each quarter revolution of the mold disk, and it goes
on the connection pin at any complete revolution. Hold out on the
drive pinion and turn the disk and drive pinion by hand the distance
indicated by the amount of the segments which have passed the square
block drive pinion. When the connecting pin enters the hole in the
drive pinion, with the mold in the estimated position, the disk
should be in time. Be sure the mold which is being used is the one
which is placed in this position. For example, if the short segment
and half of the long segment have passed the square block drive
pinion, the mold should be turned one-half the distance from casting
to ejection position. To observe what part of the segment is past
the pinion, look directly underneath the frame of the machine which
supports the mold turning shaft.
Another method of putting the disk in time is to disregard the
position of the cams, connect the mold slide, and bring the disk,
with the mold that is being used, into ejecting position. Hold the
mold turning pinion away from the pin that connects it to the shaft,
so that the disk will not revolve as the machine is set in motion.
Pull out on the starting and stopping lever, thus letting the machine
run around to normal position. Be sure that the disk locking studs
are parallel with the stud blocks before starting the machine.
It is only necessary to let the vise down, disconnect the mold lever
from the slide, and put the disk and drive pinion in time.
THE JUSTIFICATION LEVERS AND VISE JUSTIFICATION
The two justification levers are located under the metal pot and main
cams, extend forward from the back of the machine, and connect with
the vise justification rods. These levers operate the justification
rods and bar, assembled on the vise, and the vise closing lever. The
levers get their motion from rollers which follow the contour of cams
No. 4 and 5, and are held against the cams by two strong springs
in the rear of the machine. The justification bar rests on top of
two rods that are forced up and down by the justification levers in
guides in the frame of the vise. The rods are connected together by
the justification bar and a diagonal brace rod, the various parts
being connected by wing pins. The function of the justification bar
is to drive the spacebands upward to justify the line just before the
line is cast.
The right-hand lever is called the first justification lever and is
operated by cam No. 5. There are two upward movements of this lever:
The preliminary, which justifies the line lightly; and the final,
which justifies the line tightly for the cast.
When the justification lever forces the rods upward for the first
justification, the rod block moves upward at a slight angle, striking
the spaceband at the right-hand end of the line first, and the others
in quick succession. This action is so rapid that all the spacebands
appear to move upward simultaneously. This causes the line to spread
from right to left. After the first justification the spacebands
stand at an uneven height, those at the right of the line being a
trifle higher than those at the left. Since the line of matrices
must fill the entire space between the jaws in order to cast, it
is apparent that in order to get the greatest possible freedom
of action it is necessary that the matrices be pushed toward the
left gradually. Should the rod block come up perfectly horizontal,
the spacebands would move to the left at the same time they are
moving upward. This would cause them to drag on the rod block and
prevent a good lockup and alignment and a possibility of bending the
spacebands. By coming up on a slight angle, each band is practically
justified separately in its particular part of the line, and the
dragging of the bands on the rod block is greatly reduced.
The justification lever also makes a slight upward movement after the
slug has been ejected. This movement operates the slug lever, through
a roller, and pushes the slugs forward in the stick.
The spring which operates the first justification lever should be
strong enough to justify the line properly, regardless of the number
of spacebands in the line. Before changing the tension at any time,
be sure that the mold slide is properly adjusted. If the mold should
lock too tight against the line it would bind the matrices and
prevent proper justification. This would give the appearance of weak
justification springs.
The left-hand lever is called the vise closing lever, and is U-shaped
on the forward end. One arm is connected by a hinge pin to the
left-hand vise closing wedge and block. The other arm grooves around
the left-hand justification rod, beneath a lug on the rod.
After the line is brought to the casting position, the vise closing
lever moves upward, immediately followed by the justification lever.
The vise closing lever locks the left-hand vise jaw against the line
and assists the justification lever on its second movement upward.
While these two levers move almost in unison, their functions are
different. On second justification, the vise closing lever moves
upward slightly in advance of the first justification lever and
supports the left-hand end of the spaceband driving block, so that
the spacebands are all driven to an equal height. On the first
justification, the vise closing lever does not come in contact with
the spaceband driving block.
The justification spring is stronger than the vise closing spring. If
for any reason the justification springs are removed, care should be
taken that they are not changed while replacing them.
THE VISE
The vise is that part of the machine which carries, as its main
parts, the first elevator slide, the vise justification rods, the
trimming knives, the vise automatic, the vise jaws, the slug lever,
the mold disk locking stud blocks, the mold banking blocks, and the
knife wiper.
The bottom end of the vise is hinged to the base of the machine by
a shaft. The top part is locked to the machine by the vise locking
screws, which interlock with the vise locking studs on the frame.
To open the vise to first position, push the control lever all the
way in, and turn the handles of the locking screws in a vertical
position, in which position they will be disengaged from the vise
locking studs.
The vise may be opened to first position at any time when the mold
disk is not forward on the locking studs, or the first elevator
is not in the top guide. The vise should never be opened to first
position when the mold disk is forward on the locking studs because
it is difficult to get it relocked on the studs against the lockup
pressure; also there is danger of getting the ends of justification
levers out of position under the collars on the justification rods.
To open the vise to second position, let the machine turn forward
until the first elevator is resting on the vise cap, just before the
mold disk advances. Then lower to first position. Hold the vise up
with the left hand, release pawl at the extreme bottom end of vise
frame and let the vise down easily, pulling up on the first elevator
slide with the right hand. This keeps the link from being damaged.
Never let the vise down to second position unless the first elevator
is in the lower position. To do so would throw the weight of the vise
on the first elevator lever, with danger of breaking the lever.