Abstract: A retractable turn-over type rearview door mirror in which angular adjustment of the mirror member can be effected by manually operating an actuation lever. By using a certain linkage mechanism, a favorable correspondence is achieved between the direction of movement of the actuation lever and the direction of movement the mirror member. The use of a clutch unit permits the adjusted state of the mirror member to be conserved, even when the rearview door mirror is retracted and restored, by minimizing the influences of the retracting movement upon the linkage mechanism. This can be accomplished by applying a suitable amount of friction to the linkage mechanism, but, by using a lock lever which fixes the angular orientation of the mirror member when the rearview door mirror is retracted, the angular orientation of the mirror member may be kept fixed without requiring such a friction and it allows the operation of the actuation lever to be performed with a small force.

Abstract: A valve mechanism for a poppet valve of an internal combustion engine having a conventional cam and rocker arm control mechanism. Valve springs are positioned and compressed between the poppet valve and a valve spring retainer. The valve spring retainer moves relative to the engine head responsive to engine speed to further compress the valve springs with increased engine speed. A hydraulic controller operates through linkage employing a detent mechanism such that step-wise advancement of the valve spring retainer results to approximate an ideal engine speed versus valve spring force curve.

Abstract: An apparatus for controlling an exhaust system of an internal-combustion engine includes a resonance chamber having its terminating end closed and communicating with an intermediate portion of an exhaust passage of the engine, and a stop valve provided at the inlet of the resonance chamber for opening or closing the inlet in a predetermined operation region of the engine. The stop valve is actuated to effect its opening/closing operation in accordance with a predetermined operation region of the engine by means of a governor mechanism actuated in response to the rotation of a crankshaft of the engine. Through the opening/closing control effected by the stop valve, the natural frequency of the exhaust system is controlled in accordance with the operating conditions of the engine, thereby allowing the intake efficiency of the engine to be raised over a wide operation range, from low speed to high speed. Accordingly, a high output is maintained at all times.