Abstract: A dynamometer including a housing comprised of first and second parts relatively rotatable about an axis and defining a chamber, at least one brake element within the chamber carried by each part, the brake elements being in adjacency and relatively movable within the chamber, a motor and spring for moving the elements to frictionally engage and disengage the same, coolant inlet and outlet ports to the chamber, and a base mounting the housing for rotation about the axis, a transducer connected to one of the housing parts and the base, and a coupling device connected to the other of the parts and including a chuck for driven engagement with a mechanical power source, the coupling being axially extendable and allowing limited play in the radial direction.

Abstract: A dynamometer including a housing comprised of first and second parts relatively rotatable about an axis and defining a chamber, at least one brake element within the chamber carried by each part, the brake elements being in adjacency and relatively movable within the chamber, a motor and spring for moving the elements to frictionally engage and disengage the same, coolant inlet and outlet ports to the chamber, and a base mounting the housing for rotation about the axis, a transducer connected to one of the housing parts and the base, and a coupling device connected to the other of the parts and including a chuck for driven engagement with a mechanical power source, the coupling being axially extendable and allowing limited play in the radial direction.

Abstract: A test stand for vehicles having opposed motive drive outputs including a stand for supporting the vehicle to be tested in a predetermined position with its motive drive outputs free from engagement with surrounding structure, a pair of dynamometers, one on each side of the stand, a pair of releasable couplings, one drivingly associated with each of the dynamometers, and adapted to be engaged with a corresponding one of the motive drive outputs of a vehicle on the supporting stand and a movable mount for at least the releasable couplings so that they may be moved toward and away from each other and the supporting stand. Also disclosed is an improved dynamometer construction, an improved self-aligning coupling and an improved method of testing a mobile mechanical power source such as a vehicle.