Chapter 2

Beneath the flywheel was mounted the friction transmission of Charles' design. This consisted of a large drum, perhaps 12 inches in diameter, equal in length to the diameter of the flywheel and keyed to a shaft directly under the center of the crankshaft and parallel to the axles. (Diameter of drum estimated by examination of existing features.) In view of the four projections of the frame extending downward and just in front of the jackshaft position, it is likely that these supported the four jackshaft bearings. Being a bicycle manufacturer, Charles saw the need for a differential or balance gear. Accordingly, he purchased from the Pope Manufacturing Company a very light unit of the type formerly used on Columbia tricycles, and installed it somewhere on the jackshaft. A small sprocket on each end of the shaft carried a chain from the larger sprockets clamped to the spokes of each rear wheel. The lower surface of the flywheel had been machined so as to form a friction disc, with a one-quarter inch depression 3 inches in diameter turned in the center. The drum was positioned so that its upper surface was one-quarter inch below the face of the flywheel. Hanging loosely around the drum was an endless belt, one and one-half inches wide, first made of rather soft rubber packing material. The belt lay on the drum surface between the fingers of a shipper fork. While it lay under the 3-inch depression in the center of the flywheel, the belt and the drum were at rest, but when it was moved away from that depression the belt wedged itself tightly between the drum and flywheel, the resulting friction causing the drum to turn and setting the vehicle into motion. The farther the belt was moved toward the outer edge of the wheel, the faster the drum and the vehicle moved.

In September 1892, Charles, who had contracted with a Peoria, Illinois, firm to have bicycle parts manufactured, decided to move to that city. Departing on the 22d of September, he did not return to Springfield for over two years, and thus was not able to participate in the completion and testing of the carriage. At the time of his departure several units on the carriage were incomplete. A carburetor had not been built, nor had a satisfactory burner or belt-shifting device. Charles had experimented with various shifting levers just before leaving Springfield: however, as he reported later, he did not succeed in designing a workable mechanism.[15] Frank Duryea, now left to finish the work unassisted, continued the experiments with the belt shifter. He finally worked out a fork mounted on a carriage that was supported by two rods, each of which slid in two bearings. Although the short distance between the two bearings caused the shifter carriage to bind occasionally, the device was thought to be sufficient and was installed just in front of the frame. Connected to a system of cables, arms, and rods, possibly similar to the present cam-bar shifter, the shipper-fork carriage was moved from side to side by raising or lowering the tiller.

Turning now to an efficient burner for heating the ignition tube, Frank started with an ordinary wick-type kerosene lamp with a small metal tank. Wishing to use gasoline in the lamp, he found it necessary to fabricate a number of burner units before he found a type that gave him a clean blue flame. He then found the flame to be very sensitive to drafts and easily extinguished, and devised a small shield or chimney to afford it some protection.

Early in October, while still working with the burner, Frank developed a severe headache. He felt the fumes of the lamp had probably caused it, and went to his room in the home of a Mr. and Mrs. Patrick on Front Street in Chicopee. After he noticed no improvement, a doctor's examination showed he had typhoid fever, and on October 5 he was admitted to the Springfield Hospital. Here he remained for one month, being discharged on November 5. Returning to his room he was informed that because of the fear that he might be a typhoid carrier, the Patricks preferred him to find other lodgings. He readily accepted the invitation of Mr. and Mrs. D. H. Nesbitt of Chicopee to take a room with them. After several weeks recuperation in their home, he left Springfield to visit his mother in Wyoming, Illinois.

After a restful visit at home Frank Duryea returned to Springfield and finished the work on his burner. Now only the lack of a carburetor prevented a trial of the vehicle. He recalls that he studied several gasoline-engine catalogs and in one of them, a Fairbanks catalog he believes,[16] he saw a design that seemed to suit his needs. He decided to simplify the construction and operation of his carburetor and had a small bronze casting made to form the body of it. Inside was a gasoline chamber with two tapped openings, one to receive a pipe from the 2-gallon gasoline tank mounted above the engine, the other taking a pipe to the overflow tank underneath the engine, thus maintaining the gasoline level without the use of a float valve. This latter tank had a hand pump on one end so that the overflow gasoline could at times be pumped again into the main tank. Gasoline passed from the carburetor chamber through a needle valve, adjusted by a knob on top, then through a tiny tube that entered the pipe leading to the intake valve. It is not certain whether this intake pipe was at first fitted with the choke arrangement later used with the second engine.

Frank, hoping at last to be rewarded for his efforts by the sound of explosions from the engine, was ready to give the carriage an indoor trial. Standing astraddle of the reach and facing to the rear, he spun the flywheel with both hands, taking care not to get his hands caught between the wheel and the frame. His efforts were in vain, as there was complete failure to obtain ignition. He then made a new ignition tube, nearly twice as long as the original 4-1/2-inch tube, and turned down its wall as thin as he thought safety allowed. The thinner wall did not conduct the heat off so rapidly and thus kept the tube hot enough to permit ignition. After this slight change, he was able to get a few occasional explosions but he does not now believe that the engine ever operated continuously. Each explosion was accompanied by a loud knock, due, undoubtedly, to the movement of the free piston. Had the engine operated continuously, it is likely that the action of the free piston would have shortly wrecked the engine. Further efforts appeared unwarranted until alterations could be made.

= ALL AGREEMENTS CONTINGENT UPON STRIKES, ACCIDENTS AND OTHER CAUSES BEYOND OUR CONTROL

CABL ADDRESS "MOTODURYEA," PHILADELPHIA WESTINGHOUSE AND W. U. CODES

DURYEA LABORATORIES CHAS. E. DURYEA, CONSULTING ENG'R WE SOLV MECHANICAL AND OTHER PROBLEMS TESTS, SEARCHES, OPINIONS, EXPERT IN PATENT SUITS. DEVELOP INVENTIONS, ASSIST INVENTORS 35 YRS EXPERIENS. HEATING, GAS ENGIN, AUTO, ETC. FOR THINGS TO MAKE OR SEL CONSULT US A PRIDEWORTHY RECORD OF THINGS ACCOMPLISHT

PHILADELPHIA, PA. 3528 N. 18TH ST.

Dear Mr Mitman 24 Nov 1920

On the train I had some time to puzzle over that car. Been working nights to make up time lost in the day so did not hav much.

I made a sketch for you but did not show the spring that holds the circuit breaker in contact with the spark point. That thin finger was part of it. A spring was wound spirally--not helically--around the projecting end of the breaker pivot and the end of the spring hookt over the thin finger. See sketch herwith.

Just how the central end of the spring wire was fastened to the square of the pivot I do not kno. We did in some cases bore a hole thru and simply stick the spring thru but this put most of the action right at the bend in the wire and it broke quickly. So in other cases we fitted a light grooved spool or pulley and wound the spring around this and so avoided a sharp bend. If this was used it has been lost with the spring. A couple generations of boys playing in that barn was too many.

The Haynes steering sketch also worries me. If that vertical post came up thru that slot in the floor the crank had to be long as the sketch shows in order to get over to the driver conveniently. Then if he tried to make a complete circle with it he could not reach far enuf forward to do it easily. And he had to make a turn or two be cause H shows bevel gears of about same size so the post had to make same number of turns the worm made. Sketch herewith to illustrate my thought.

Yrs for the historical facts Chas. E. Duryea=

The two pistons were first pinned together into a single unit which was probably ringless, since it is believed the walls of the outer piston were too thin to admit rings. Because the piston no longer struck the exhaust valve, a short rod had to be screwed into the pistonhead; this pushed the valve shut at the completion of the exhaust stroke. The remaining problem, the opening of the exhaust valve, was solved by screwing a device to the side of the cylinder which operated from the sidewise motion of the connecting rod. This device shifted a small spacer between the piston and the striker arm of the exhaust-valve rod, permitting the piston to push open the exhaust valve. On alternating strokes the spacer shifted back out of the cylinder; therefore, no contact was made between piston and striker arm. Sometime in February 1893, the altered engine was successfully started.

At last the transmission could be tested. Will Russell had come upstairs to watch the trial, and according to a statement by him, given April 30, 1926, Frank, standing to the right of the engine and behind the rear axle, reached forward and with the combination tiller-belt-shifter, moved the belt into driving position. The carriage started forward, but as it approached the wall of the building Frank discovered that he could not get the belt back into the neutral position. In desperation, he grasped the rear axle with both hands and was dragged a short distance, attempting to stop the machine, before it struck the wall. He had, however, sufficiently retarded it so that no damage was done.

This short trial demonstrated some of the weaknesses in the friction transmission. Since the speed of the surface of the flywheel, in feet per second, increased in proportion to the distance of the point of contact from the center, the outer edge of the belt attempted to run faster than the inner edge. This conflict of forces not only put an undue load on the motor causing a great loss of power, but it also created a tendency for the belt to work towards the outer edge of the flywheel. Conversely, when the operator desired to return the belt to neutral, it strongly resisted any efforts to slide it toward the center of the wheel, as Frank had learned from the wall-bumping incident. Furthermore, the rubber belt on the friction drum had worn so badly that it had to be replaced at least once during the brief experiments.

At this point, Frank and Markham felt that the carriage was anything but satisfactory. While they were trying to decide what steps should be taken next, Frank added one last improvement to the engine. Fearing that the uncooled cylinder might suffer damage from the excessive heat, he constructed a copper water jacket in two halves, drew them together around the cylinder with clamping rings and soldered the seams. Asbestos packing sealed the end joints where the jacket contacted the cylinder. Thinking back, Frank does not recall that he ever used a water tank with this engine, though he does remember adding water through the upper jacket opening. The engine was run only for a few brief periods following this addition.

Obviously this collection of patchwork could not fulfill their needs for an engine. First, it would be next to impossible to start if the body was placed on the running gear, as the flywheel then would be practically inaccessible. The absence of rings on the piston caused a further loss of power to the already overloaded engine. The flywheel was too light. The absence of any form of governor left the operator with no control over the engine speed. Ignition was poor, partly owing to the hot-tube arrangement, and partly to the excessive distance between the engine and the carburetor. Frank wrote his brother Charles on February 6[17] that in his opinion the mixing chamber was so far from the engine that the gasoline could not be drawn into the cylinder as liquid, and it was too cold to vaporize and go in as gas. Thus he had difficulty in getting the engine started. When it did start the explosions were unmuffled. Less important to him than these defects, however, was the awkward and unsightly wooden engine mount.

Description of the Automobile

Sometime in the early part of March, Frank convinced Markham that he could construct a new and practical engine, using only previously tried mechanical principles.[18] Drawing up new plans for this engine, he took them to Charles Marshall who began work on the patterns for the new engine castings. After the patterns had been delivered to the foundry, Frank left Springfield for a short vacation in Groton, Connecticut, where he visited with his fiancée. On May 17, 1893, several weeks after his return to Springfield, they were married.

The engine castings were undoubtedly received from the foundry prior to Frank Duryea's marriage, and the work of machining and assembling the parts went on through the spring and summer. This engine, still on the carriage in the Museum of History and Technology, is cased with a water jacket, and has bases on top to support the front and rear bearings of the starting crankshaft, and a base with port on the upper right side where the exhaust-valve housing was to be bolted. On the underside are two flanges, forming a base for seating the engine on the axle. A separate combustion chamber is cast and bolted to the head. Inside this chamber are located the igniter parts of Frank's electric ignition system. The fixed part, an insulated electrode, is screwed into the right side of the chamber and is connected with the ignition switch outside, to which one of the ignition wires is attached. A breaker arm inside is pinned to a small shaft extending through the top of the chamber. Around the breaker-arm shaft is a small coil spring (originally a spiral spring, according to the letter of Charles Duryea shown in fig. 17), anchored below to a thin brass finger extending toward the right side of the car, and above to a nut screwed tightly onto the shaft. This nut is also the terminal for the other ignition wire. The action of the spring keeps the breaker arm and the electrode in constant contact until the push rod on the end of the piston strikes the arm and separates the two parts. Breaking contact then produces the ignition spark. Since the mechanism would spark at the end of both the exhaust and compression strokes, the battery current is conserved by a contact strip, on the underside of the larger exhaust-valve gear, by means of which the flow of current is cut off during the greater part of the cycle.

On the left side of the combustion chamber is bolted the housing containing the tiny intake valve. A comparatively weak spring seats this valve in order that the suction created by the piston can easily pull it open. Clamped onto the valve housing is the intake pipe, enclosing the choke and carrying the carburetor on its forward side. The choke consists of two discs which block the pipe, each with four holes at the edges and one in the center. Turning one disc by means of a small handle outside, so that the four outer holes cannot coincide with those in the other disc, decreases the flow of air and causes all air to rush through the center hole, where the tiny carburetor tube passes through. The present carburetor was transferred over from the first engine. When Frank later installed the engine on the carriage he noticed the close proximity of the intake pipe to the open end of the muffler. Believing that the fumes might choke the engine, he attached a long sheet-metal tube to the intake pipe so that fresh air would be drawn in from a point farther forward on the vehicle.

Moving to the right side of the engine brings the exhaust-valve assembly into view. This valve is contained in a casting bolted over the exhaust port in the side of the cylinder, and from the casting a pipe leads to the muffler underneath. The valve is pushed open by a rod connected to a crank which is pinned to the lower end of a shaft carrying an iron gear on top. This gear is in mesh with a fiber gear, keyed to the upper end of the crankshaft, with half the number of teeth. This ratio permits the opening of the exhaust valve on every other revolution.

The crankshaft of the first engine was retained for the new engine, thus giving the two engines the same stroke of 5-3/8 inches, but the bore was increased slightly to 4-3/8 inches. With this larger bore and with the engine speed increased to 500 rpm, Frank rated this engine at 4 hp.[19] A heavier flywheel, with a governor resting in the upper recess, was pressed onto the crankshaft. As the operator of the vehicle had no control over the carburetor once he climbed into the seat, this governor was necessary to maintain regular engine speed. Its function was to move a slide on the exhaust-valve unit to prevent the valve from closing. Thus the engine, with the suction broken, could not draw a charge on the next revolution. During the recent restoration of this carriage it was found that while most parts are still intact, nearly all of the governor parts are missing. A description of them must therefore be based on the recollections of Frank Duryea, along with certain evidences seen on the engine.

Just on top of the flywheel, and surrounding the crankshaft, rest two rings, 3-7/8 inches in diameter. Into the opposing surfaces of these rings are cut a series of small inclined planes, appertinent to each other. On the outer circumference of the upper ring two pins pass through a pair of lugs mounted in the flywheel, causing the ring to rotate with the flywheel, yet permitting vertical movement. Underneath, the other ring is allowed to turn slightly when, by means of two connecting links, the arms of the governor push against them. These two arms, each constructed like a right angle and pivoted at the apex, are arranged directly opposite each other far out in the flywheel recess. As a weight on one angle of the arm presses outward by centrifugal force against a spring, the other angle presses inward against the connecting link mentioned above. The turning of the lower set of inclined planes against the fixed set above raises the upper ring and the fork resting on it. The upward movement of this fork, which is a continuation of an arm pivoted to a bracket midway between the crankshaft and the slide carrying the exhaust valve stop, causes the other end of the arm to drop, pulling the slide down with it. In this manner the closing of the exhaust valve is blocked, preventing the intake of the next charge, and therefore the engine misses one or more explosions until it slows to its normal speed.

A starting shaft is mounted above the engine casting by a cast-iron bracket on either end. The front end of the shaft has a bevel gear which is held by a coil spring behind the front bracket, just out of contact with a bevel gear pressed onto the upper end of the crankshaft. The short rear portion of the shaft is a tube which slides over the main shaft. Fitting the removable handcrank to the squared end of the hollow shaft and turning the crank clockwise, will advance the forward section of shaft through the medium of a pair of inclined collars. With the bevel gears now engaged the engine may be cranked. When ignition begins, the inclined collars slide back down each other's surfaces, the shaft is again shortened, and its bevel gear springs free of the one on the crankshaft.

While Frank worked on his engine, he realized that certain parts of the old running gear would need to be altered or replaced. In view of the heavier and more powerful engine, he felt the old wheels, probably having compressed band hubs, were inadequate. He procured a set of new, heavier wheels[20] with Warner-type, cast-iron reinforced hubs. The angle iron frame, apparently sturdy enough to carry the added weight, was retained, but it was decided to install a heavier rear axle.[21] The front axle assembly was at first allowed to remain unchanged, as was the steering apparatus. A short time later when the engine and friction transmission were bolted in place on the running gear, Frank saw that the rigidity of the framework had an undesirable effect. When the vehicle passed over any unevenness in the shop floor, the framework was distorted and caused the jackshaft bearings to bind tightly enough on the shaft to prevent its being turned by hand. In order to provide the 3-point suspension necessary to eliminate this distortion, Frank attached the forward parts of the framework to an extra wooden spring bar, installing between this bar and the front axle a vertical fifth wheel of the type ordinarily used in a horizontal position in any light carriage.

Frank next calculated that with the faster running engine the speed of the vehicle would be about 15 miles an hour, too much for the heavily loaded wheels. As he intended to make use of the original transmission, he decided to decrease the speed by increasing the size of the friction drum. He accomplished this by sliding a heavy fiber tube over the original drum, bringing its diameter to approximately 14 inches. The original shipper fork carriage was improved by separating the original bearings to a greater distance, and eliminating one of the two bearings on one end. This permitted a smooth and free operation of the small sliding carriage.