Part 5

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.

METAL POT ADJUSTMENTS

There are two pot leg bushings which fit over the vise frame shaft and project up into the fork of the pot leg. These support the metal pot and hold it in position to lock up with the mold. The position of the pot in relation to the mouthpiece is determined by four adjusting screws in each pot leg and bearing against the bushings. These screws permit the proper alignment of the mold and mouthpiece.

The holes in the mouthpiece, through which the metal passes to the mold cell, should align with the smooth or constant side of the slug, as this side of the mold always remains in the same position. When using the mold liners for the different points of thickness of slugs, the position of the mold cap changes. If the holes should align with the rib side of a slug of large size, when changing to 6-point slug the mold cap would cover the holes, thus shutting off the flow of metal and causing an imperfect lockup or imperfect slugs.

The two screws at the top and bottom of each pot leg are for the purpose of aligning the holes in the mouthpiece with the constant side of the mold.

To make this adjustment, remove the mold and take it apart. Clean thoroughly the mold and mold pocket. Leave the cap off and place the constant part of the mold back in the pocket with a 30-em left-hand liner and a constant right-hand liner in the mold. Remove the plunger pin for safety. Turn the machine until the first elevator rests on the vise cap. The mold should now be in front of the mouthpiece. Raise the first elevator, holding it up with a piece of wood, one end under the head of the slide and the other on the upper end of the vise automatic stop rod. Close the vise. Unlock the mold cam lever, move the mold disk forward by hand so the locking studs can enter the bushings. Turn the machine by hand until the mouthpiece advances against the mold. Release the two front adjusting screws a trifle so the pot legs can move freely while making the adjustment. Release the lock nuts and move the top and bottom screws until the bottom of the holes in the mouthpiece are in line with the constant part of the mold, and the two end holes are showing within the liners. Tighten the lock nuts and the front adjusting screws after finishing the adjustment.

A great amount of lockup trouble is caused by the mouthpiece on the metal pot not locking up squarely against the mold, due to the front and back pot leg screws being out of adjustment or the mouthpiece being warped.

To adjust the pot legs so the mouthpiece will lock up squarely with the mold, place the machine and the mold (without the cap) and the 30-em liners in the same position as when adjusting the height, but have the mold cam lever connected to the mold slide. Leave a little space between the mold and the mouthpiece. Place a piece of tissue paper at each end of the mold between the mold and the mouthpiece. Have the paper just inside the ends of the liners. Turn the machine forward until the pump lever is ready to go down for the cast. Be sure the plunger pin has been removed, to prevent accidentally forcing the metal out of the pot.

If the left-hand paper should be tight and the right-hand paper loose, loosen the front pot screw at the left and turn in on the back screw. This will move the left end of the mouthpiece farther back. Adjust with the front and back screws in this manner until both papers are held tightly.

After completing the adjustment, replace the cap on the mold and turn the machine to normal position.

Another method of testing the pot lockup is to let the machine make the quarter revolution which brings the mold in front of the mouthpiece. Disconnect the mold lever and pull the mold slide forward. Apply a thin even coating of a mixture of red lead and oil, or printers’ ink, to the back of the mold. Be sure to have the mold clean. Hold out the mold disk driving pinion, so the disk will not revolve, and let the machine run around without casting. The mixture will transfer from the mold to the mouthpiece. If the mouthpiece is touching only on one end of the mold it can be adjusted by the screws in the sides of the pot legs. Adjust them to swing the crucible to bring about a tight fit, repeating the above test until the transfer is registering evenly the full length of the mouthpiece. After each test wipe off the mouthpiece and mold, for any oil or too much red lead or ink would give a false impression.

If the mouthpiece touches at both ends and not in the center or in the center and not on the ends, it indicates that the mouthpiece is warped and the above adjustments would not be satisfactory.

When the mouthpiece is warped or high, it is necessary to take out the high spots with a fine file or an oil stone. Take off a very little of the surface at a time and repeat the tests with the red lead until a proper lockup is secured all the way across the mouthpiece.

After fitting up a mouthpiece in this manner, the vents should be cut to their original depth.

After making the pot adjustments, test the mold slide adjustment to make sure that it brings the face of the mold to within .010 of an inch from the face of the matrices. See that the pot lever has the 1/16 of an inch play needed during lockup.

Be sure the washers on the pot lever shaft are so placed that the sides of the lever do not bear on the cams.

POT LEVER

The pot lever is located directly back of the metal pot and, through cam No. 8 and the pot cam roller, gives the pot its forward and backward action. There is a cushion spring on the pot lever eyebolt that connects the lower end of the pot lever to the pot jacket. This spring gives the lockup of the pot and mold and takes up all excess motion of the lever during the lockup.

There is a short piece of pipe pinned to the eyebolt inside of the spring, which prevents having too much tension on the spring. The nut on the front is the adjusting nut. This nut has a washer next to the spring, to keep the spring from being forced over the head of the nut. This nut should be tight against the pipe. With the end of the rear nut against the pipe on the bolt, there should be 1/16 of an inch from the back of the pot lever to the head of the nut when the machine is in casting position. This 1/16 of an inch adjustment gives the correct lockup to the pot and also prevents breaking the lever by too much pressure.

The pot lever spring should be examined frequently, as back squirts will be caused by a spring which is broken or worn. This trouble is caused by not giving pressure enough to the mouthpiece when it is being locked against the mold for the cast.

A lever spring weak, worn, or out of adjustment will also cause an uneven height of the matrices, due to the lack of pressure during the cast.

When it is necessary to remove a pot lever spring, pull the pot forward by hand, place a support beneath the pot jacket to hold the pot lever roll off the cam. Remove the pot balancing spring, take off the rear nut on the eyebolt and push back on the lever. The spring can then be removed.

The roller in the pot lever has nine anti-friction roller bearings. These rollers should frequently be examined for wear, and if found worn should be renewed, because a set of worn anti-friction rollers will also cause an imperfect lockup. When renewing these rollers, put in all nine new ones. If a roller is worn or broken, or the bearing pin or pot lever roller worn, there will be play between the lever and cam, which will prevent a tight lockup.

To take out the pot lever: Pull the pot forward by hand, place a support beneath the pot jacket, remove the balancing spring, loosen the screw in the upper shaft bearing, and pull the shaft out. On the upper shaft bearing on each side of the pot lever, are washers of varying thickness. These washers are for the purpose of adjusting the pot lever sidewise so it will not bind on the main cams. When taking out this shaft be careful that the washers are not lost or mixed.

Take out the wing pin that holds the eyebolt to the pot jacket. Place the lever on the bench and take out roller bearings by releasing the set screw and pulling out the roller pin. Before replacing the bearings, in the lower roller, coat them with vaseline or hard grease. By placing a small piece of an old keyboard rubber roll in the hole, so the bearings fit around it, they will be held in place until the pin is slipped through. The pin will force the rubber out.

Fastened to the back of the pot lever, at the right-hand side, is the pot return cam shoe. As the main cams revolve, the pot return cam, fastened to cam No. 9, comes in contact with the shoe, pulling the pot away from the mold after the slug has been cast.

REMOVING A POT

To remove a pot from a machine: Remove the plunger, dip as much metal out of the pot as possible. Lower the first elevator to the vise cap, and let vise down to second position. Remove the mold slide. Take off the pot leg caps. Loosen the front adjusting screws in the pot legs. Loosen the nut on the pot lever eyebolt, to release the spring tension. Take out the pot lever shaft, and remove the pot lever. Take off the mold disk shield and pump stop bracket. The pot can then be lifted out by placing a rope through the supports on the jacket for the pot lever shaft, so that the pot can be raised up while it is being guided out of the machine by taking hold of the bottom of the pot legs.

SLUG TROUBLES

An imperfect face on slugs could be caused by any of the following: Holes in the mouthpiece not inside the slug line, holes in the mouthpiece closed, or partly so; vents in the mouthpiece filled up, or insufficient ventage; dross in the throat of the pot back of the mouthpiece, mold cell rough inside, due to being damaged; mold cell dirty or oily, inferior metal, holes from the pot to the well stopped up, plunger not clearing the well holes, plunger or pot well dirty, governor not working properly, temperature of the metal not adapted to the size of slug being cast, cold metal. Too large a hole in the mouthpiece will give a small slug an imperfect face.

When the slug is cold, the body of the slug may be solid and have a stringy or flaky appearance, and the face may be imperfect, some of the letters being poorly cast or blurred. The base of the slug usually will be good.

When the slug is too hot the face is good, but the body is hollow and spongy and the slug is light. It is imperfectly formed, due to the heat of the metal.

A bright bottom on a slug shows that the mold knife has trimmed a thin layer of metal from the bottom of the slug, due to an imperfect lockup, the excess metal running over the bottom of the mold. If the mouthpiece makes a perfect contact with the mold at the moment of casting, there will be no excess metal and the slug will show a clean bottom.

An imperfect lockup can be caused by any of the following: Cold metal due to low gas pressure, dirty burners, gas burning in mixer, improper packing around the mouthpiece, or improperly packed metal pot; hot metal, too much metal in the pot, dirty plunger or well, air vents cut too deep, air vents cut too high above holes, dull mold knife, pot cam lever roller or bearing pin worn, pot lever not working freely on the lever shaft, due to gum or lack of oil; metal on the bottom of the mold, mold knife out of adjustment, mold disk guide out of adjustment, leaky mouthpiece, warped mold, pot lever spring weak or broken, accumulation of metal back of the mold disk, mold cap guides bent, loose stay bolt, loose adjusting screws on pot legs.

GASOLINE BURNER

There are three methods commonly used to heat a metal pot: Gasoline burner, gas burner, and electric heater.

The gasoline burner in most cases is undesirable on account of cost, time, and fire hazard; but through the lack of electrical current or gas it must sometimes be used.

There is a burner designed for either gasoline or kerosene by the Linotype Company. This burner will give complete combustion in burning either gasoline or kerosene. It has no threaded joints and, therefore, no joints to leak. It is equipped with a positive mouthpiece burner and control. This burner can be taken apart for cleaning without removing any screws. The fuel is forced to the burner from a pressure tank. With this improved mouthpiece burner control, the burner may be adjusted for a slug of any size. The best results can be obtained from a gasoline or kerosene burner by keeping it clean.

GAS BURNERS

The gas burner used to heat the metal pot is made up of three sections. The largest burner heats the main part of the pot. Another pipe leads up to heat the throat, and a small burner heats the mouthpiece. The pot and throat burners are held near the pot by a rod which passes through the pot jacket and under the pot burner. The mouthpiece burner is held in place by a support and a screw which extends into the pot jacket.

The gas enters the burners through the pot gas burner cocks. The gas cock that feeds the pot burner has a larger inlet hole than those of the throat or the mouthpiece burners, because more gas is required for the pot burner. The inlet holes must be kept open and free from soot and metal, but should never be drilled larger at any time. Should you find a burner tip that has been drilled, a new tip should be applied by driving out the old tip and inserting a new one.

As the gas leaves the gas cock it passes through the air mixer. The air mixer is open on the bottom side and allows a flow of air to mix with the gas. Unless the gas is mixed with the proper amount of air it will not make sufficient heat under the pot. Do not at any time allow the gas to burn in the mixer. Sometimes when lighting the gas or when the pressure is low the flame may light in the mixer. It should then be turned out and relighted, holding a flame near the burner. Should the gas be allowed to burn in the mixer the heat will be lost before it reaches the burner; and furthermore, the burner will soon become clogged with soot.

From the mixer, the gas passes upward into the pot burner. The pot burner consists of a circular shaped chamber which is covered with a flat plate. The top rim of the chamber is notched, which allows the gas to flow out around the top plate, forming a very hot flame. The flame from the burner should be of a bluish appearance. A dirty burner will cause a yellow flame. There is very little heat in a yellow flame, and when the burner shows a yellow flame, it usually indicates a dirty burner or a fire in the mixer. A very important part of the burner is the top plate. When this plate becomes warped or badly burned it should be replaced with a new one.

Two pipes lead out from the front end of the pot burner to carry a flame up under the crucible throat. These pipes are fed through the front gas cock. The gas passes through a separate chamber in the front side of the pot burner. It is very essential that these burners are working properly as they keep the metal hot in the throat of the crucible.

The mouthpiece burner consists of a small pipe into which holes have been drilled to allow the gas to escape. This burner extends underneath the mouth of the crucible the full length of the mouthpiece. There are two extra holes on the right-hand end to give a little more flow of gas at that point. The holes should never be reamed out larger, but should be kept clean and free from soot or metal. Metal sometimes gets through the holes and partly fills the pipe. This retards the free flow of gas and causes loss of heat to the mouthpiece.

Good slugs from a machine are to a great extent dependent on good, clean burners. Only experience on various machines will enable one to tell just how much flame to carry in each burner on a machine. The governor should regulate the pot and throat burners, when once adjusted. However, it is better for the operator to regulate the mouthpiece burner with the gas cock, according to the size of the slug being cast.

GAS POT HINTS

Keep gas tips clean and round. A blue flame is the heating flame. Watch the mouthpiece burner. Clean out metal and dross which forms there due to metal dripping from the mouthpiece.

If the mouthpiece burner does not give a long, blue flame after cleaning, procure a new mouthpiece burner and replace the old one.

A yellow flame indicates too little air in the mixture. This can be caused from too large a hole in the gas tip, air inlet partly closed, dirty burners, or gas burning in the mixer. Sometimes the hole in the tip of the gas cock is too large. The hole can be paned with a small hammer and reamed out with a small broach to the proper size.

The pot burner top plate is fastened by four stove bolts. These bolts become charred and brittle from the heat, and the nuts will be very hard to start. Have a few of these bolts on hand when changing the plates, because the plate must fit tightly to the burner to obtain the best results.

Good slugs can not be produced with dirty burners. Keep them clean. It is better to spend ten or fifteen minutes cleaning the burners than to lose an hour trying to regulate the temperature of the metal.

TO REMOVE THE GAS BURNERS

Disconnect the hose on the older styles or the gas pipe union on the newer styles. Separate the mouthpiece burner from the crucible at the sleeve. (This operation is not necessary on the thermostat connections.) Pull out the rod which holds the burners in place and lift them out.

To remove the mouthpiece burner, take out the screw which holds the support to the jacket of the pot, slip the connecting sleeve back, and pull the burner to the left.

PRESSURE GOVERNOR

The pressure governor is used to control the flow of gas to the machine and to keep it at an even pressure. The governor is placed on the main gas line so the gas must pass through it before flowing to the machine. It is not necessary to have a pressure governor on each machine, for where there is more than one machine, a governor large enough to supply any amount may be secured.

The gas enters through a valve in the bottom of the governor and passes up into the supply chamber. From the supply chamber the gas flows out to the machine burner. The pressure in the supply chamber is regulated by an inverted cup float. The lower rim of the float is immersed in mercury, which causes the cup to float and also acts as a seal to prevent the gas escaping through the top of the governor. Weights are placed on top of the float to counterbalance the gas pressure. Fastened to the float is a rod which passes through the gas chamber. This rod connects to and operates the valve in the inlet opening. When the gas pressure is increased it raises the float by its pressure. When the float raises, it at the same time raises the valve in the intake, which decreases the opening through which the gas enters. Should the pressure in the main fall off, the float sinks deeper into the mercury, and the opening in the valve is opened, permitting a greater flow of gas. Thus the pressure in the gas chamber is held uniform, because the greater the pressure on the float, the smaller the opening for the gas to enter.

To regulate the pressure, place weights on the float until sufficient gas flows to the burners to give a good flame.

MERCURY GAS GOVERNOR

In a governor of this style, the gas from the main line passes through the upper pipe, down through the internal tube, and escapes between the end of this tube and a column of mercury in the mercury tube, passing up behind the internal tube, and out through the lower pipe to the burners.

To prepare the governor for use, remove the adjusting rod and pour in mercury until it rises in the mercury tube almost to the lower end of the internal tube, which can be seen through the glass disk at the side of the governor. When the metal in the pot reaches the proper temperature, the surface of the mercury stands at the lower end of the internal tube, but a notch in the side of this tube above the mercury permits a flow of gas sufficient to prevent shutting the gas entirely off underneath the pot. When the temperature falls, the mercury in the holder and column will be cooled, and its surface lowered in the tube. This will allow an increased flow of gas to the burner until the temperature of the pot is raised to the proper point.