The Wonder Book Of Knowledge Part 65

In following the final a.s.sembly line from the point where the chain conveyor engages the frame and axles, the visitor is impressed with the dispatch with which every movement is executed. The gasoline tank, for example, comes down from the fourth floor on a conveyor outside of the building, and drops through a chute onto a bridge over the a.s.sembly line. On this bridge is located a gasoline pump, from which each tank receives one gallon of gasoline before it is installed in the car.

After the gasoline tank is a.s.sembled, a number of small units are added, such as the hand brake control lever, gasoline feed pipe, and fender irons, until the point is reached at which the motor is placed in the frame.

Ordinarily the setting of a motor in the frame is a long operation, but in this a.s.sembly the motor is elevated by a hoist, and lowered into place while the cha.s.sis is moving along the conveyor track. From this point, other small parts are added, and bolts tightened, until the growing cha.s.sis reaches the bridge on which the dash unit is deposited by a chute from the second floor, where it is a.s.sembled. The dash unit includes the dash, complete steering gear, coil, horn, and all wiring ready to be attached to the motor, so that its installation is rapid.

Further along, such parts as the exhaust pipe, m.u.f.fler, and side pans for the motor are quickly fastened in place, and the wheels are brought into the a.s.sembly.

There will be noticed the vertical chutes, extending through the ceiling. Down through these, from the third floor, come the wheels, with the tires mounted and inflated to the proper pressure. From this point the cha.s.sis moves under the bridge upon which are stored the radiators, which have been delivered by a belt conveyor.

At the end of the a.s.sembly line, the rear wheels on the finished cha.s.sis drop into a set of revolving grooved wheels, sunk into the concrete floor, and driven by an overhead motor. Two ends are accomplished by this operation. First, when the wheels of the car revolve with the grooved wheels, this motion is transmitted to the differential, through the drive shaft to the motor, limbering up all these parts. The second is that while the parts are being limbered up, the switch is turned on and the motor started.

[Ill.u.s.tration: INSPECTION OF FRONT AXLE AFTER MACHINING]

At the end of the line the complete cha.s.sis is driven out into the yard under its own power. Guided by practiced hands it moves swiftly out into the yard, turns sharply and enters the final inspection line. A corps of inspectors at this point takes charge of the cha.s.sis, and the responsibility for each part is a.s.signed to some one man.

From the final testing line the cha.s.sis is driven to the body chutes, which extend into the factory yard from the third floor of the new six-story building, and are so constructed that the cha.s.sis may be driven under them. The bodies are let down the chutes on belt conveyors, picked up by small derricks and swung over onto the cha.s.sis.

The bodies are at this time placed on the cha.s.sis merely as a means of a rapid transportation to the freight cars, for in ordinary transportation the bodies are packed in the cars separate from the cha.s.sis.

In the rear of the main plant are two six-story buildings each 60 feet wide by 845 feet long, built parallel to each other and connected by a crane-way 40 feet wide the full length and height of the buildings.

The boiler house, which furnishes the steam for heating the entire plant, is located in the rear of these buildings. The method of heating is worthy of particular interest, as the air is forced over coils of steam pipes located in pent houses on the roofs, and from this point is driven down into the various rooms through the hollow columns which support the floors. In the summer, cool washed air is forced down through these same columns, maintaining a normal, even temperature, compatible with the state of the weather.

[Ill.u.s.tration: INSTALLING MOTOR ON FINAL a.s.sEMBLY LINE]

Various unit a.s.semblies, small machine departments, and store rooms are located here in addition to all the body work.

Practically the entire first floors are used as a receiving department, where all the material consigned to the company is checked and inspected. Railway tracks run the full length of both crane-ways, facilitating the unloading and loading of supplies and parts.

The body department occupies the greatest amount of s.p.a.ce, requiring, with the upholstering department, most of the three upper floors. In addition to this work the construction of tops, curtains and radiators is carried on, and a large s.p.a.ce is used for the storage of equipment and parts, such as lamps, horns, tires, etc. A part of the second floor is devoted to the storage and the shipping of parts to branches and agents.

Having seen the body placed upon the cha.s.sis, the visitor pa.s.ses along toward the north. In succession are the chutes on which the crates of fenders are sent down from the fourth floor of the main factory building to the shipping platform. Here is also a chain elevator, which raises the wheels out of the freight cars to a runaway on which they travel by gravity to the third floor of the main factory. With this device it is possible for three or four men to unload about 6,000 wheels each day.

[Ill.u.s.tration: MECHANICAL STARTER--END OF FINAL a.s.sEMBLY]

One pa.s.ses the loading docks, where crews of six to eight men each, working as a unit, remove the bodies and wheels from the cha.s.sis, and load them into freight cars. So proficient are these loaders that a freight car is loaded in twenty minutes. Approximately 150 loaded freight cars are sent out every day. Besides these factory shipments there are more than 300 loaded freight cars in transit each day from branch factories.

The bodies are shipped separate from the cha.s.sis, being stood on end in one-half of the car and protected from dust by coverings.

The cha.s.sis are put in the other end of the car, the first one being carried in, minus the wheels, and placed in a diagonal position.

Brackets of cast iron, for holding the axle to the floor, are made in the foundry. The front axle rests on the floor, and the rear axle rests against the opposite wall near the top of the car. A block, with a hole which just fits the axle, holds it against the wall.

[Ill.u.s.tration: THE BODY CHUTE, WHERE BODIES ARE PLACED ON EACH CHa.s.sIS]

The next cha.s.sis is brought in and placed with its front axle opposite the first one. In this way the cha.s.sis alternate until the car is full.

The s.p.a.ce in the center of the car contains the fenders, and other removable parts of the equipment.

Just beyond the loading docks is the foundry.

The foundry is one of the most interesting divisions of the entire plant, and ranks, perhaps, as one of the most unique in the country, as far as practice and equipment are concerned. As a general rule, foundry practice has not shown the changes in an increase of production that machine departments have, but in this foundry, due to standardization of parts and specialization on the one car, it has been possible to devise and install the unique equipment now used, which brings this department down to the plane of expense and up in the labor-saving efficiency prevailing throughout the entire plant.

[Ill.u.s.tration: CRANEWAY, SHOWING LOADING PLATFORMS]

This department works twenty-four hours a day, in three shifts of eight hours each; iron is being melted and poured continuously during the day and first night shifts. An average of over 400 tons of iron is poured daily, and 426 tons of gray iron have been poured in a single day. This tonnage is especially interesting, as it is produced on a floor s.p.a.ce of only 36,324 square feet.

All this iron is poured on overhead power-driven mold carriers, which travel about twelve feet per minute. These mold carriers have suspended from them pendulum-like arms, on the lower end of which is a shelf. The molders who make the molds for the castings are stationed alongside of these conveyors; the molding sand with which they fill the flasks is stored overhead in a hopper, the gate of which discharges directly onto the molding machine. There are two molders for each part, one making the "drag," or lower part of the mold, the other making the "cope," or the upper half. When these two halves of the mold are finished they are put together, or "closed" on the shelf of the conveyor, which carries the finished mold to the man who pours the molten metal. The molten metal is brought to this man's station by means of large ladles, suspended on a trolley on an I-beam track, running from the cupola through the entire length of the foundry. This does away with the necessity of carrying the ladle of iron a long distance, thus saving much time and lessening the liability to accidents.

[Ill.u.s.tration: CONTINUOUS CORE-OVEN]

[Ill.u.s.tration: QUENCHING STEEL FORGINGS IN HEAT-TREATMENT OPERATION]

While the mold is being poured it is in constant motion, and continues so from the pouring station to the end of the conveyor, where the casting is shaken out of the sand. The casting is thrown to one side to cool, the flasks are hung upon hooks on the arm of the conveyor, to be returned to the molder, and the sand drops through a grating in the floor onto a belt conveyor; on this conveyor it is dropped on an elevator, raised overhead and "cut," or mixed with new sand, and pa.s.sed on to another conveyor, which deposits it in the hoppers above referred to, ready for the molder's use. In all this journey the sand is never shoveled.

In casting cylinders, on account of their size and the care needed in setting the cores, a different style conveyor is used. The molder, instead of putting the mold on a pendulum conveyor, places it upon a track, where it is moved by means of a chain. During this travel the various cores are set, and the molds closed, moving to the point where the men with large ladles pour the mold. From this point it is transferred to another track. As it travels down this track, the casting is given an opportunity to "set," or cool. At the end of this line it is shaken out over a grating, and the sand handled in the same manner as on the smaller conveyors.

[Ill.u.s.tration: STRAIGHTENING CRANK SHAFTS ON STEAM HAMMERS]

As soon as the castings have cooled sufficiently they are put into great horizontal cylinders, called tumblers. Small metal stars are placed in these tumblers with the castings, and when the tumbler is full it is started revolving. This shakes all the sand from the castings and they come out clean and bright. This process continues for some time, depending on the size of the castings. Near the tumblers are the grinding wheels, upon which are ground off the rough edges and the castings put into shape for the machine shop. They are sorted, inspected and counted before removing from the foundry.

Another interesting feature is the handling of sand in the core room.

The sand is handled entirely in a gallery built above the room, equipped with storage bins and sand mixers. Over each core-maker's bench is a hopper, connected with the floor of the gallery. When the sand is mixed it is dropped through holes in the floor into the hoppers, which deposit the sand on the bench convenient for the core-maker.

This core room contains perhaps the only endless chain core oven in this country in which are two endless chain conveyors. These have hanging upon them large sets of shelves, upon which the cores are placed for baking. It is impossible to over-bake or under-bake a core, as the rate of travel of the conveyor is fixed at a speed which leaves the core in the oven the correct length of time.

All the aluminum parts as well as a large proportion of the bra.s.s, are also cast in this foundry.

The process of heat-treating steel forgings before they are machined is one of the most scientific and accurate features in the manufacture of this car. Vanadium steel is used throughout the construction of the car.

It has been found from long and deep experimental work by engineers, that the structural condition of steel may be changed by the application of heat, and with certain conditions ascertained, by bringing a piece of steel to a certain temperature, and then setting the molecular condition in the steel by sudden cooling, or quenching, that the steel of a crank shaft can be made to stand impact, that the steel of a front axle can be made a most efficient agent to withstand vibration. Practically every forging in the car is made of a special steel, for which a special formula of heat-treating has been worked out, in accordance with the work, or strain, the part must stand in the finished car.

It is by the use of this high-grade, scientifically heat-treated vanadium steel that it is possible for the company to manufacture a light-weight car, which has the ability to stand up under severe usage, and to sell at the low price at which it is sold today.

The heat-treating department contains about seventy-five large furnaces, which consume from 5,000 to 6,000 gallons of fuel oil per day. It is into these furnaces that the various forgings are placed for heat-treating. In each one is introduced a pyrometer, connected electrically with a switchboard located in a separate building. This switchboard is very similar to those used in telephone exchanges. The operator takes the temperature reading of every furnace on his board about every minute. The furnace foreman is notified by the operator as to the temperature by means of small colored electric lights, located above the furnace. The lighting of all the colors at the same time is the signal to pull the heat or, in other words, extinguish the fires and empty the furnace. After the required heat has been reached, the forgings are allowed to either cool in the air, be covered with pulverized mica, or quenched in a special solution, as the case may require.

[Ill.u.s.tration: PYROMETERS BY WHICH THE TEMPERATURE OF THE FURNACES IS REGULATED]

In this department are also located many grinding wheels and tumbling barrels, similar to those used in the foundry, so that the various forgings may be put in first-cla.s.s condition before they are laid down in the machine shop.

[Ill.u.s.tration: THIS BELT CARRIES THE FINISHED PARTS AND Sc.r.a.pS FROM THE PUNCH PRESSES]

The operations in the manufacture of the crank case, or engine pan, of the motor is of interest for several reasons, and the visitor has the opportunity of viewing these processes.

The crank case in itself is interesting because it is made from drawn sheet steel, instead of cast aluminum, as was once thought necessary.

[Ill.u.s.tration: TAKING INDUSTRIAL MOTION PICTURES

Operator suspended from traveling crane.]

The presses on which these crank cases are drawn are especially worthy of note, for they weigh about fifty tons each, and exert a downward pressure of about 900 tons. It is necessary that this drawing be made in four operations; the first and second are particularly interesting, on account of their depths, which are 5-1/2 and 9-3/16 inches, respectively. After each drawing operation it has been found necessary that the case be annealed, to restore the strained or calloused surface produced at certain points by contact with the dies, to a soft, ductile condition, to conform to the balance of the case, or, in other words, to produce a h.o.m.ogeneous condition of the surface.

This annealing is accomplished by a furnace through which the cases are moved by a chain conveyor onto an elevator which raises them up through the roof, and down again, depositing them near the press which is to perform the next drawing operation. While moving on this elevator the cases are cooled so that they can be handled as soon as they are lowered.