Abstract: An internal combustion engine with two crankshafts which are parallel to each other and are installed in a common casing. One of the crankshafts is driven whenever the engine is running and the other crankshaft is driven only when the engine is operated at maximum load. Prior to starting of the cylinders which rotate the other crankshaft, the other crankshaft is gradually accelerated to the speed of the one crankshaft by a friction clutch which is coaxial with the one crankshaft. Once the acceleration of the other crankshaft to the speed of the one crankshaft is completed, and the other crankshaft assumes a predetermined angular position with reference to the one crankshaft, the friction clutch is disengaged and such disengagement entails activation of a positive-engagement clutch between the two crankshafts. The friction clutch can constitute a component part of or it can be integrated into the positive-engagement clutch.

Abstract: An internal combustion engine wherein a first group of cylinders rotates a first crankshaft and a second group of cylinders can rotate a second crankshaft which can be separably coupled to the first crankshaft by an accelerating friction clutch. The clutch permits slippage of a first clutch member which is driven by one of the crankshafts relative to a second clutch member which drives the other crankshaft while the other crankshaft undergoes gradual acceleration to the speed of the one crankshaft. Once the speed of the other crankshaft matches or closely approximates the speed of the one crankshaft, and the other crankshaft assumes a predetermined angular position relative to the one crankshaft, the first clutch member ceases to slip relative to the second clutch member. The accelerating clutch can be interposed between two camshafts one of which is driven by the one crankshaft and the other of which drives the other crankshaft during acceleration of the other crankshaft.

Abstract: The combination, including a flywheel couplable to and uncouplable from an internal-combustion engine, depending upon specific circumstances, and a clutch for coupling the flywheel to and for uncoupling the flywheel from the internal-combustion engine, the clutch comprising an entrainer disc secured to a rotatable part of the internal-combustion engine against axial and rotary displacement relative thereto, the entrainer disc having two friction surfaces, a pair of pressure plates each having a respective opposing friction surface located on opposite sides of the entrainer disc, a cup spring actuatable for positively moving the pressure plates in opposite directions, the cup spring having a radially outer region operatively engageable with one of the pressure plates, and a radially inner region operatively engageable with the other of the pressure plates, an axially fixed tilting support being disposed on an axially fixed part of the flywheel, the flywheel part being mounted for relative rotation with the rot