Detailed explanation of the AUTOPULSE fuel pump, its operation, and specifications.
| Identifier | ExFiles\Box 41\1\ Scan009 | |
| Date | 23th September 1925 guessed | |
| Page 8 slightly with the increase in voltage. Two-thirds of the rated voltage will deliver 85% capacity, and one-third of the rated voltage will produce operation and supply sufficient fuel for a good strong engine idle. THE VARIATION IN LIFT, represented by the variation in height of the pump over the fuel level, has only a slight effect upon the capacity for any condition encountered upon a vehicle. A change from 1 1/2 feet to 5 feet will reduce the capacity about 1/2 gallon per hour. The variation in lift, due to grade in the case of an automobile, does not affect the delivery pressure. The suction stroke is magnetic and an increase in suction, due to increased elevation or other causes, is compensated for by an increase in electrical power. [Image of a five-unit fuel pump assembly] "Quintette" (1/4 size) Height, 3 1/2"; width, 5 3/4"; length, 11". Bracket holes, 1/4"; center distance, approximately 8 3/4". Pump centers, 2 1/8". All openings 1/8" pipe tap The capacity is directly affected by the CHANGE IN PRESSURE UPON THE DELIVERY SIDE of the AUTOPULSE. The delivery stroke is spring-actuated and adjusted to raise a column of gasoline to a maximum height of 50" to 60" above the pump outlet. This “head” represents the pressure at which the electrical contacts will be held apart and, therefore, no current is used or fuel pumped. This pressure condition is instantly attained upon the closing of the carburetor float valve when the pump is installed at the same level as the carburetor. The calibration pressure will be directly increased or diminished as the pump is raised or lowered in respect to the carburetor, with change in capacity resulting. When the fuel is flowing, the delivery pressure is governed by the restriction at carburetor valve and the pressure is less than when at rest. It requires a gasoline head of about 40" to force gasoline at a rate of 8 gallons an hour through a round orifice 1/8" in diameter. FOR GREATER CAPACITY than the UNIT rating, additional units are required. Any number of units can be used in multiple or manifolded. The illustration below shows a five combination. When connected in this manner each unit operates independently of every other unit and each will deliver its proportion of the fuel used at all times to the extent of the full capacity of each, and be governed by the same pressure conditions as is each unit. That is, the maximum pressure attained does not increase with the increase in the number of units, but, for any given quantity, the delivery pressure will be maintained at more nearly the maximum, the greater the number of units. The rated capacity of a five-unit pump is 40 gallons of gasoline per hour with an unrestricted delivery of 50 to 60 gallons per hour. This "quintette" is suitable for a “Liberty Twelve” engine. (450 H.P.). The AUTOPULSE CAPACITY FOR PUMPING AIR is greater than for fuel. When pumping air alone the stroke lengthens and doubles in speed. Because of this characteristic, a considerable air leakage into the suction line can be overcome and a quick pick up, from an empty system, obtained. There is no time lag in the delivery of fuel from the AUTOPULSE. It will instantly change from zero to full capacity upon demand. Full delivery pressure at the carburetor will usually be attained. Page 9 before the engine is cranked. The ignition switch being operated in the customary manner. LIFE The life of the AUTOPULSE is MEASURED BY THE NUMBER OF GALLONS OF FUEL PUMPED and is practically independent of the time period required. When there are no air or gasoline leaks, there is no waste pumping. Laboratory tests indicate that the life of AUTOPULSE UNIT, when pumping gasoline, is from 10,000 to 20,000 gallons, and a single unit should, therefore, outwear most engines of corresponding capacity. The tests also show that the average duty, without need of adjustment, should be the pumping of more than 6,000 gallons. Few automobiles use more than 1,000 gallons per year and the average is less than 500 gallons. The wearing away of the contact points is compensated for by other characteristics to a great extent. In some cases, however, there may be a capacity loss of 10% during the first 6,000 gallons pumped. Should AIR BE ALLOWED (See Operation Tests and Checks) to enter the suction line, waste pumping will be caused to an extent represented by the proportion of air entering and the useful life will be reduced in a like proportion. The total air pumping in the life of a vehicle would probably not be an hour. It occurs only for a short period when the system is first supplied with fuel and upon other occasions more or less accidental. The AUTOPULSE operates at a high rate of speed and under a severe strain when upon air alone; but it will withstand several hundred hours of continuous air pumping at its rated voltage before rupture of the pumping element occurs. The pumping element or bellows was especially developed for the AUTOPULSE. It is strengthened by overlapping and soldering at the bends, where the greatest strain occurs, thereby causing the flexing to occur at the proper place—in the diaphragms. The process used in producing this bellows has resulted in greater uniformity and several times the life of the usual bellows product. The AUTOPULSE is GUARANTEED AGAINST DEFECTS IN MATERIAL AND WORKMANSHIP. EFFICIENCY The AUTOPULSE requires so little power that its amount need not be taken into account in respect to battery capacity. It requires about one ampere to pull the stroke, but, on account of the intermittent action, the ammeter reading or average flow at rated capacity is only 1/4 to 1/2 ampere. About 50 ampere hours are required for pumping 1,000 gallons, or less than 1/2 a small battery charge for a year or more of hard automobile driving. The values given are for six-volt rating. For twelve volts the current values are reduced nearly one-half. The best operation is obtained in winter weather when the need is greater. The lower the temperature, the higher the efficiency and the lower the voltage value at which operation will take place. TECHNICAL EXPLANATION The AUTOPULSE is the result of more than two years of intensive experimental and research work. It has been perfected with the invaluable assistance and enthusiastic co-operation of the engineers of many of the principal automobile factories. A novel type of ELECTRICAL MOTOR has been devised EMBODYING TWO NEW MAGNETIC OPERATION PRINCIPLES and several new construction details. Its action is reciprocating, the armature being angularly oscillated upon two steel balls, located near its edge and embedded in hardened steel sockets. A third ball completes the assembly and is located over the axis of the other balls in a spring socket. This bearing holds the armature rigidly against unbalanced magnetic side pull, and prevents lost motion due to wear. The stroke, which is controlled by the new magnetically operated breaker principle, is positive and timed as to length and speed (not a vibration). The ARCING OF CONTACTS is reduced to the vanishing point by means of a “short-circuited secondary magnet winding.” This is another new magnetic principle. It replaces, and is cheaper than, a condenser. It is much more effective than any condenser which could be installed in so small a container, and functions as follows: The current in the “working” coil is rising rapidly at the time of break and its magnetic field has induced a current in the closed circuit secondary, which is in the reverse direction to it. This current, being demagnetizing, neutralizes the effect of self-induction at time of break. [handwritten note: Incorrect E.P.P.] A SUB-ATMOSPHERIC CHAMBER is provided upon the suction side of the pumping element. The stretching of the air in this chamber allows the armature to complete its stroke without drawing an excessive current, which would otherwise be caused by the inertia effect of a long column of liquid in the suction pipe. It provides a more uniform flow of liquid in this pipe. The operation is explained by reference to the “cut-away prospective” drawing. Before the current is | ||
From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).