Special machines and fixtures
Three years ago, I heard a story about the Ford Tool Designing Department. I have not attempted to verify the incident, but judging from observations, made during the past few months, I am satisfied that it could have easily happened. It seems that one of the representatives of an eastern concern had been called into conference with the Ford engineers, regarding the design and building of a machine for a certain purpose. In going over the drawings, the Eastern Manufacturer suddenly pointed to the blueprint and said, "This is evidently a mistake. You specify an output of 200 per hour—this, obviously, is wrong; you mean per day." "No, I think that is right," said the Ford man. "The designer of this machine rarely makes a mistake, and if he says 200 per hour, I believe he must have figured out some way to do it. You know we check things up pretty carefully here." A heated discussion ensued, in which the Eastern Manufacturer pointed out that 40 per day was considered a fair production on such a part. "Well, it is easy enough to find out," said one of the Ford officials; "just tell the man who designed this machine to come in here a minute." The man came. The output specification was called to his attention. His only comment was, "Well, what about it?" "You can't do it," said the Eastern Manufacturer. "There is no machine built that will do it.
Two hundred an hour! Why, it is out of the question." "Well," said the engineer, "if you will go down into the machine-shop on the main floor, you will find a machine doing it—we built one to try it out, and it is doing what we thought it would." Needless to say, the discussion ended there.
The Ford factory is filled with such machines. During the course of the last three years, over 140 special machines and several thousand special dies, tools, jigs and fixtures have been made. Fifty machines and 2,500 to 3,000 jigs and fixtures are not considered an unusual output for the 55 men employed in this department.
Improvements are constantly being introduced. Hardly a week passes when some radical change is not made in the various departments.
The less efficient machine is displaced by the better one. Not only the Ford engineers, but the men in the shop, are constantly trying to do things in an easier and better way. Like most great inventions, their best machines are often the simplest —so simple that when one sees them for the first time, the same old
question arises—"Why didn't I think of that way before?" Of course some of the machines are complicated. They can't help but be. They are required automatically to do several different things; cam motions, toggle joints, links, automatic trips, intermittent motions, all these demand complicated looking machines, at least. In some machines the action is so complicated that wooden models are made before the design itself is completed, to test out all the motions and see that there is no locking point or other interfering element. The machines are frequently laid out full size, sometimes on a black-board, sometimes on a floor with chalk of different colors, sometimes merely a perspective drawing is sufficient.
Painting the Rear-Axle Assembly
On page 308 is shown such a sketch of a machine, just designed for automatically painting the rear-axle assembly. As explained in the chapter on painting, the rear axle was formerly dipped in a tank of enamel, by hand. It had to be handled several times and two men were required to do the work. With this new machine, it will be possible for one man to hang the rear-axle assembly on a moving chain which will carry it up over the tank. When it has reached this point, two levers will automatically thrust protecting thimbles over both ends of the axle shaft, the paint tank will travel up six feet, completely immersing the rear axle in the painting liquid, immediately returning to its former position, after which the part will proceed on its way down the track to the baking oven, as before. A complete cycle of operations will be performed in thirteen seconds; so it can be readily seen how easily and rapidly this work can be done with the new machine.
A New Cooling Tower
Every minute that a part is not in process, it is taking up space and costing money. Therefore, the Ford engineers have, in a very commonsense way, tried to eliminate all breaks in a process line, and handle the material in such a way that it will be undergoing some needful operation at all times. For instance, immediately after the drawing operation on the crank case, it is necessary for this part to be annealed to relieve the strain set up by the very considerable draw required to form this piece.
While these annealing ovens have been located near these draw presses for some time, yet a considerable amount of handling has been necessary even with this favorable arrangement. Not content with this condition , the Ford Company now proposes to erect a combination annealing furnace, cooling tower, and endless-belt conveyor which will receive the part immediately after its drawing operation, anneal it, cool it under the most favorable of slowly decreasing temperatures, and deliver it to the next press in proper condition and at a low enough temperature for its next drawing operation. Briefly, this innovation will consist of an annealing furnace with a charging door at one end and an upright chimney tower at the other.
In this tower, which acts in a dual capacity (as a means of carrying off some of the gases, and also as a slow cooling chamber for the part being annealed) is an endless-chain conveyor provided with carriers, onto which the heated crank cases are shoved through the rear opening of the furnace. The part travels up one side and down the other, where at a suitable point near the bottom, it is automatically released and slides down to its place in the pile near the next draw press. The illustration on page 309 shows the construction of this new labor-saving combination.
Some Special Radiator Machines
Up in the radiator department in the new building on Manchester Avenue, will be found another good example of the manner in which work in progress is carried through a furnace. Here, the operation is one of soldering. In the immediate back-ground of the upper illustration on page 311 will be seen a furnace with two transverse openings, an endless-chain conveyor equipped with hanging frames, and the necessary mechanism for driving it. This conveyor travels an equal distance from each end of the furnace. The work is fed in at both ends and taken out at both ends, the operation is practically continuous.
The radiators, consisting of fins and tubes, are built up, as will be described later, supplied with solder and inserted in the traveling frames. Carried along by the conveyer, they traverse the furnace which is kept at a temperature of 750 degrees. In this way, more than 1,900 radiators can be soldered every 8 hours.
The making of a radiator was formerly considered a very diffi cult operation, but Ford ingenuity has made it a very simple operation.
As is generally known, a Ford radiator is made up of a large number of transverse brass fins, intersected by 95 vertical tubes.
The problem that now arises is, how to get these parts together in the shortest possible time. If you have ever tried to put 95 tubes through even one strip of thin brass, and then fit these same 95 tubes through the holes in several dozen more, you will realize how difficult it is to accomplish this operation successfully in a short length of time. Putting the pages in a loose-leaf ledger is bad enough—this is a thousand times worse. In the early stages of the automobile industry, this work was done by hand. Gradually, of course, other methods were adopted. But, while the fins are racked, the tubes are still put in by hand in some of the radiator factories.
Therefore, to see a radiator made in the Ford factory is an interesting experience; one that will not soon be forgotten. The photograph on this page shows how this is done. Two types of racks are used—one like that shown in the left fore-ground of the picture, for stacking up the fins ready for the insertion of the tubes; the other, bearing a marked resemblance to an old-time candle mold, receives the tubes. Now comes the interesting part—after these two racks have been filled, the one containing the fins is placed on the metal table in the center; the one containing the rods is positioned opposite it, so that the tube holes in the fin-frame are in direct line with those of the tube mold. Mounted in the center of this table and moving under power in either direction, at the will of the operator, is a ram, on both ends of which are 95 projecting rods located and spaced in accordance with the holes in the radiator molds. Therefore, after the work is all in place, the operator simply starts the machine and the tubes are shoved out of one mold into the other, completing the whole job in one operation and in a remarkably short time. The machine works in both directions so that when the ram is being withdrawn from one set of molds, it is forcing the tubes into the corresponding one on the other side. This machine has a capacity of 1,200 radiator cores every 8 hours.
In the same department is an other very interesting Ford machine , or rather an attachment which is fitted to a standard press.
It is shown in the lower illustration on page 311. It will turn out 25,000 radiator fins every eight hours. Ribbon brass is fed in from a reel on the left side of the machine . The edges are rolled up and turned over, 95 holes punched and the piece cut off automatically.
It runs with an intermittent motion , affected by the use of a "Geneva cam movement." Entirely automatic, it will run continuously, with very little supervision. This machine has increased the output of fins from six to seven thousand per day, over the hand-operated machine formerly used. This is a characteristic example of Ford policy in increasing output and reducing labor cost.
Making the Ford Gasoline Tank
In the gasoline-tank department there are two machines and several fixtures which are well worthy of extended mention. Not only the machines employed in forming, but the method used in soldering are unusual. The galvanized iron is first blanked out on a press shown on page 314, that turns up the sides, punches the filler and sediment-cup holes, and embosses the ribs. It then goes through a set of rolls that hems the edge and shapes the barrel on rollers, shown above, at the left, on this page.
It is then delivered to a machine designed and built by the Ford Motor Company for the purpose of "rolling in" the ends, shown in the right-hand picture on page 315. In action, it is simplicity itself, but the mechanism operating the rollers is rather complicated. Briefly, it consists of two sets of revolving spindles, upper and lower, the latter provided with a link motion which enables them to be raised or lowered at will, by means of the lever shown at the left in the illustration on page 315. This lever controls the left-hand spindle, a similar one on the other side operating the right-hand one. The machine is designed to roll in the ends of the gasoline tank.
The operation is as follows: the workman picks up a circular disc forming one end of the tank and places it on the lower horizontal revolving plate; he then places the cylindrical body of the tank on top of this, adding another disc which serves as the other end. A swing of the floor lever elevates the whole assembly until it is securely clamped between the two rotating face plates; the power is then turned on and the upper and lower rolls, mounted on the swinging frame, gradually begin to approach the ends of the cylindrical tank. As the top and bottom discs are greater in diameter than the tank-body flange, they begin to curl over as the rollers travel toward the body, until finally both end joints are securely made.
At this point the rollers are automatically withdrawn and resume their former position; the power is turned off, the floor lever thrown back, and the tank lifted out. This result is accomplished by means of a very ingenious system of cam motions. As the splash plates have been soldered in, previous to this operation , the tanks are now practically complete and ready for final soldering.
The circular joints are soldered by hand (page 315), by means of a gas torch. After the filler plugs and sediment cups are added, the tanks are tested under air pressure in water.
The longitudinal seam is soldered in a novel manner on a special Ford soldering conveyer shown on page 316. A strip of solder wire cut to size is laid along the seam, soldering fluid is brushed on, and the tank, in a moving-chain trough, is carries under a six-jet gas flame which melts the solder and completes the job.
In this same department are two rather interesting die fixtures used for making tie-straps for the tanks. The left-hand picture on page 318 shows one with its finished product, performed in one operation . The right-hand picture on the same page shows the other, which carries two dies required for the forming and perforating of this piece.
Special Machine and Cutters for Filleting Crank-Shaft Bearings of Cylinder
Located just off the main aisle on the east side of the main craneway, are two interesting filleting machines, one of which is shown on page 317.
Simple in operation and very efficient, they play an important part in the rapid production work of the Ford cylinders. As will be noted in the accompanying photograph, the cutters are mounted on rapidly rotating shafts controlled by a hand lever which moves the cutters to the right or left. The cylinder casting, upside down, is deposited on a receiving table. When the lever is in neutral position, cutters are equidistant from the bearings on either side. A movement of the lever to the right, fillets the left-hand side of the bearings; a movement to the left fillets the right-hand side of the bearings. The operation is performed in less time than it takes to tell about it and little care is required to perform the operation perfectly, because the movement of the lever is limited in both directions so that only the proper amount of metal can be removed.
While in other factories the various testing machines for trying out minor assemblies are usually grouped by themselves, in the Ford factory they are placed in the process line if possible.
The upper figure on page 317 shows the special machine designed by the Ford engineers for testing the transmission. Mounted on a suitable connecting shaft, the transmission assembly is caused to revolve and the planetary gears which make up this unit are tested out separately.
The three lever brakes, each of which can be applied separately, make it possible to operate and test the "reverse," "slow speed," and "brake," in a very short time. This machine is located in the transmission -assembly line. The elements of the machine are clearly shown.
Spindle Punch-Drilling Machine for Making Wood-Screw Holes in Floor Boards
On page 319 is shown a special attachment which has been added to an ordinary press, for the purpose of rapidly "punch-drilling" holes in wooden floor-boards. This machine requires no extended explanation, as its operation is readily understood.
Power Filing and Burring Machines
Scattered through the Ford factory are a number of power filing and burring machines for cleaning up the edges of gears and taking the burrs off the edges of small parts. The cut on page 320 shows such a machine. Only the rotating spindle projects above the work table.
Sometimes the rotating spindle is set in a horizontal position and carries a circular file face-plate against which the work is held. These machines present no unusual features, but like many others machines of like nature, add very materially to the capacity of the shop.
Forming and Hardening Spring Leaves
Down in the north-east corner of the machine shop, a very interesting machine is being installed, which is to be used for forming, and quenching spring leaves. See the upper figure on page 321. It is entirely of Ford design and presents many novel features. It is made up of two main parts—a large steel box acting as a tank for holding the quenching oil, and a rotating frame shaped very much like the paddlewheel on a Mississippi steamer. This rotating member, controlled by a rather complicated cam motion, has six projecting arms revolving from the front to the rear of the photograph. On each one of the "paddles," two jaws are carried; the outer one stationary, the inner moving in and out automatically. A hot spring leaf is taken from the furnace and inserted between one of these sets of jaws. Pressure on a trip pedal near the floor closes the jaws automatically, squeezing the steel to shape and causing the mechanism to rotate through an angle of 60 degrees. It stops automatically in a position so that the next set of jaws is ready to receive another spring leaf. Simultaneously with these actions, the leaves are allowed to drop out on the other side, which is the front of the picture, as shown. A tilting shelf swinging through an angle of 90 degrees automatically places itself in the proper position and at the proper time to receive the quenched leaf as the jaws release it. A further movement of the machine causes this shelf to rise to a vertical position and the spring leaf tumbles to the floor.
Cam-Shaft Grinding Machine
On page 321 is shown a cam-grinding attachment which has been designed to fit a regulation grinder. Mounted on trunnions so that it will swing back and forth in order to follow the outline of the master cams, this fixture holds the cam shaft in position in front of the grinding wheel.
By moving the carriage back and forth it is possible for the workman to bring the successive cams opposite the grinding wheel. Inasmuch as the cam shaft virtually forms an extension of the shaft carrying the master cams, any movement of the latter is duplicated by the former. It is only necessary for the operator to move the carriage longitudinally from one cam to the other. A middle bearing prevents the cam shaft from springing out of line.
This machine has a capacity of about 115 cam shafts every eight hours, an increase of about 25 more than that secured with the former method of grinding.
Special, Ford Fly-Wheel Balancing Machine with Drilling Attachment
The drawing on page 324 shows a special machine designed for balancing fly-wheels. A combination of an electrically driven drill and a wheel-balancing mechanism is unusual. It will easily be seen how such a combination of two operations, making it unnecessary for the fly-wheel to be lifted out and taken to a drill press for each drilling operation, makes for increased production.
Cam-Shaft Shaping Machine
Page 325 shows the most unusual and interesting machine to be found in the Ford shops. It is entirely of Ford design. Cam shafts were formerly cut on milling machines. It was a slow process and rather expensive. The cutters cost $8.50 apiece and one man was required to operate each machine. Therefore when it is known that this machine has increased the capacity from 90 to 275 and that one man can supervise three of these machines, it can be readily seen what a wonderful increase in production has been made by the utilization of this entirely new method of cutting cams.
In action, this machine is essentially a shaper. It carries, however, eight cutters, so that work is done on all cams at the same time. The tools are controlled by a system of master cams which bear down on the top of the cutting tools and insure a positive cut on the work. The cam shaft is driven from both ends and supported by a bearing in the center.
The machine is electrically operated and the cut is controlled by means of a stop regulated by the hand wheel shown on the right-hand side of the picture. The cutters, which are held against the master cams by means of springs, move up and down in accordance with the cam outline.
This machine has a capacity of 275 cam shafts per day of eight hours. It takes about twenty seconds to load, and less than two minutes to complete a shaft.
Needless to say, in this chapter attempts to describe only a few of the many interesting machines and fixtures to be found in the Ford shops, but those selected illustrate the simplicity and directness which always characterizes Ford design.