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The new passive restraint system comprises a pad or cushion automatically retained in place against the chest of a car occupant, and a knee restraint. In normal circumstances, the chest restraint is held in contact with the occupant by light spring pressure so that he is free to lean forward to reach door handles and the like; in an accident, the arm supporting the pad is locked in position, and forward movement of the chest is then controlled by the force exerted by the pad. Variation of this force with distance is determined by the characteristics of an energy absorber, which governs the movement of the arm. The forward movement of the lower part of the body is controlled by the knee restraint which must be capable of considerable deformation.

The geometry and behavior of several front-seat passive belt configurations have been studied and evaluated. General design criteria are discussed. The preferred solution is a three-point belt with two ends attached to the door. The belt straps automatically, and for comfortable exit, the occupant may make a slight manual operation. Crash tests indicate that the belt performs approximately as a standard three-point belt. Door strength, retractor strength, strap strength and tension, seat influence, etc., have been tested. Curves are given for recorded and computed data, including old and new severity index.

The principles of seatbelts for the VW-vehicles with a retractor which is sensitive to vehicle deceleration and to webbing acceleration is described. In addition possibilities are shown to reduce the Severity Index with energy absorbing devices in the seat belt retractor or in the B-pillar-ring. The results show that the requirements from the NHTSA up to Notice No. 16 of Docket 69-7 cannot be fulfilled in relation to the Severity Index (SI).

Safety belt restraint systems can be improved by using semipassive and full passive devices which lead to a high and increasing utilization without a considerable decrease on the user's comfort. Improvements for increased injury protection are given by introducing belt force limiters and devices which eliminate the belt slack at the moment of crash beginning and, furthermore, give a certain preload to the belts, enabling the passenger to take part in the vehicle deceleration almost from crash onset. Results of sled tests complete the description. A final comparison with the airbag shows the higher protection possibilities of belt restraint systems against injuries.

Automatic seat belts are presented as a method of complying with proposed government regulations requiring passive protection against occupant injury from vehicle collisions. Operational models have been installed in current model cars. The proven field performance of belt systems now in cars reducing fatalities and injuries is the fundamental basis for considering the automatic seat belt. Several design approaches for automatic seat belts are explored and described. Webbing and hardware modifications to adapt the configuration of the belt systems to present car interiors are described in detail. Dynamic testing results are presented to compare crash performance to current production belt systems now in cars.

This paper describes a semipassive seat belt system that was one of a series developed during a program to examine the possibilities of modifying seat belt designs to meet the passive occupant restraint requirements in the original proposed amendment to FMVSS 208. As such, many features are prohibited by the interlock ignition option of the latest amended 208. This semipassive seat belt installation utilizes a system of electrical interlocks to achieve an improved seat belt wearing rate. It is estimated that a usage rate of 95% would be achieved, making it more effective than an air bag.

The determination of the impact load capability of vehicle brake system components is necessary to verify product design requirements. Testing methods and procedures must minimize the variables inherent in vehicle “spike stop” applications to assure the acquisition of accurate, meaningful test data. This paper describes the design, development, and characteristics of a device currently in use for “spike stop” brake applications at a vehicle test facility.

This paper presents the results of an investigation into the thermal performance characteristics of solid rotor disc brakes. Using the results of mathematical and computer analyses, as well as road test experiments, relationships for predicting the temperature and thermal stress response of the rotor are developed for braking in a single stop. Special emphasis is given to determining the onset of surface cracking as a result of different braking conditions. A design criterion for avoidance of surface rupture in a single stop is developed. Results obtained in the analytical and experimental study indicate that acceptable correlation between temperature prediction and measurement require an exact assessment of the distribution of braking energy between tire and brake and rotor and pad. Thermally induced surface rupture was found to occur when the theoretical compressive surface stress exceeded the yield strength of the material.

Studies have been conducted for determining the distribution of the lubricant in a crankcase scavenged two-stroke cycle engine. Presently, it is not obvious how newly supplied oil reaches each engine part and how it leaves the engine through the exhaust gas. Furthermore, it is desirable to know what percent of the supplied oil is exhausted during the scavenging period and what percent is burned in the combustion chamber with the gasoline. Three different lubrication systems were studied utilizing radioisotopes: premixed fuel and oil; manifold supply system for the oil; and crankcase supply system for the oil. The lubricating oil was tagged with tritium. The lubricating oil behavior in the crankcase scavenged two-stroke engine has been investigated within the limited operating condition of these tests. The tests show that almost all supplied oil was exhausted within one hour, and the remainder was exhausted gradually.

The effects of surface roughness of brake drums on coefficient of friction (brake torque) and lining wear were investigated using typical commercial grey cast iron drums and typical commercial linings. Sample and inertia dynamometers were used. The surface roughness is found to significantly affect the coefficient of friction (brake torque) and lining wear, though the effect is dependent upon the lining compositions. The significance and implications of these findings are discussed.

This paper describes experiments involving airbag systems. Because there is the least amount of data on the tolerance of children to impact, the out-of-position child was used in the experiments. After careful consideration it was decided that a primate of approximately the same weight as a child be used, which would provide the most realistic evaluation of potential injuries. The animal chosen for the experimental program was the baboon. Five distinct positions were chosen and this paper describes in detail the experimental physiological conditions and results.

This paper discusses some of the very serious problems associated with the use of anthropomorphic dummies in crash testing of automobiles. These problems arise primarily from the non-repeatable behavior of the dummy and from the unknown correlation between it's behavior and that of the human. The combination of these factors leads to scatter in test results and in their interpretation which are well beyond the usual range of engineering practice. The systems approach to crash testing can only be placed on a true scientific basis by increasing our understanding of the dummy/human relationship and by decreasing test scatter. Test programs relating to these problem areas are described. These tests demonstrate that the results obtained are heavily dependent on the data analysis scheme employed. Results obtained by use of the mathematical analog technique are compared to other methods.

From November 1970 through August 1971 an extensive program of static and dynamic air cushion inflation tests utilizing human volunteers was conducted at Holloman Air Force Base, New Mexico, sponsored by the Department of Transportation. Forty-one full cushion deployment static firings were made, with air cushion hardware and seating buck environment designed by General Motors. The static series was followed by 35 dynamic sled firings of human volunteers, beginning at 8.6 g (15.1 mph) and culminating at 21.7 g (31.5 mph). A major objective of both the static and dynamic test series was to identify changes in air-cushion design found necessary to improve its protective capability for human beings. Because of the severity of cushion deployment, one modification was made following the initial static tests: The orifice diameter size of the bag inlet was reduced from 1.0 to 0.6 in to diminish the rapidity of bag inflation. This modification proved effective in the dynamic series.

This paper examines the engineering and economic feasibility of inflatable restraint systems and structural modifications required to achieve passive protection for occupants in passenger car frontal collisions at 50 mph equivalent barrier speed. Vehicle structural modifications, already proved in prototype tests, are examined for compatibility in car-to-car crashes. The special aspects of inflatable restraint systems capable of 50 mph protection are also discussed, taking into account the improvements in system behavior made possible by structural modifications. Costs and benefits are also projected. It is concluded that cost-effective 50 mph protection can be achieved.

Exhaust emission tests run on an engine dynamometer are compared with those run on a chassis dynamometer. The worst case average difference between the chassis and engine dynamometer mass emissions, obtained over a period of 6 months, was less than 7%. The elimination of the driver, vehicle, and chassis dynamometer yielded significant improvement in test reproducibility with respect to carbon monoxide and oxides of nitrogen. A digital computer was used to control speed and throttle position of the engine dynamometer experiments. No transmission was used. The computer and engine dynamometer duplicated transient effects of transmission, vehicle, and chassis dynamometer.

Successful computer monitoring and control applications require careful problem and system definition, especially if a system integrator is used for a turn key type installation. The concepts of interactive design and vendor involvement are presented as fundamental to writing specifications and defining system requirements for successfully solving the problem.

Mainframe vendors generally are very recent entrants into the systems management marketplace. Customer demands for complete service and support of their application development and implementation, particularly in the sensor-based areas, were responsible for their entry. This paper discusses the life cycle of a typical systems management contract from preproposal analysis to Phase 1 (design) to Phase 2 (implementation) to customer turnover. Also presented is a typical statement of work from a typical proposal.

Multicylinder 2-cycle, water-cooled outboard motors were modified to allow testing of up to three different fuel-oil blends simultaneously. A special “floating laboratory” test barge was designed and constructed for operation of the outboards. Engine protection and metering facilities were provided in the control room on the barge. Repeatability studies were then carried out to determine the precision of the test using multiple references in four outboard motors. Results indicated that a high degree of precision was attainable. Some results from fuel and lubricant evaluations, which followed, are included.

In Japan, test methods for evaluating the performance of 2-cycle engine oils have been developed separately by each 2-cycle engine manufacturer. The reason for this is that there are are many differences in engine performance and in lubrication methods. Evaluation through bench tests is used as a valid method for screening engine oils prior to field tests. Field tests are conducted eventually as the most reliable test method for evaluating the performance of engine oils. Yamaha Motor, one of the leading Japanese 2-cycle engine manufacturers, developed a “70 min engine test method” in 1963, which can be conducted in a relatively short period of time with good reproducibility. In this paper, several problems regarding Yamaha's 70 min engine test method are discussed.

The application of automation to dynamometer testing of engines has led to the development of specialized circuits and techniques to compensate for limitations inherent within the electromechanical systems used to implement automation theory. Stable, quick response to a programmed speed change has been achieved for engine-automatic transmission testing by the use of a parallel feedback technique. Vehicle simulation using analog computer circuitry and road test data is used to calculate torque requirements from programmed acceleration-time and velocity-time curves. Similar circuitry is used to calculate engine-transmission output torque from dynamometer parameters.