Abstract: A circuit for controlling a solenoid clutch wherein a gap is present between an electromagnet and an associated attracted member when in the disengaged state. The circuit controls the level of exciting current supplied to an exciting coil of the solenoid clutch in such a way that the width of the gap is first reduced to zero and then the slip rate of the solenoid clutch is gradually changed from 1 to 0, whereby the solenoid clutch gradually reaches the completely engaged state, making it possible to smoothly engage the solenoid clutch without the occurrence of mechanical shock.

Abstract: A vehicle fuel-efficiency warning device for use in a vehicle driven by an internal combustion engine, which device comprises elements for producing a first detecting signal when an engine speed exceeds a predetermined upper limit, elements for generating a limit signal corresponding to an upper limit characteristic of the position of a member for adjusting the amount of fuel supplied to an internal combustion engine, the upper limit characteristic including a portion having a drop-off tendency in accordance with the increase of the engine speed, elements for producing a second detecting signal when the position of the member exceeds the upper limit of the member as determined by the limit signal; and elements for issuing a warning in response to the occurrence of the first or the second or both detecting signals.

Abstract: An apparatus for obtaining a signal relative to rotational speed of a rotary element is disclosed. The apparatus comprises a permanent magnet and a magnetic body which relatively approaches or moves away from the permanent magnet according to the rotational speed of a rotary member. A magneto-sensitive switch is operated in response to the change in intensity of the magnetic field produced by the relative motion between the permanent magnet and the magnetic body. Therefore, there can be obtained an apparatus which is small in size and high reliability.

Abstract: The present invention is a plunger-type electro-magnetic actuator which produces a constant attracting force regardless of the position of the plunger. A tip portion of the plunger is tapered and a magnetic pole piece of the solenoid adapted to electro-magnetically attract the tip portion is provided with a tapered hole having a diameter larger than the outer diameter of the plunger. An additional magnetic pole piece is substantially displaced from the magnetic pole piece along the advancing direction of the plunger so as to increase the operational range of the plunger.

Abstract: A governor for use in a diesel engine which comprises an integral combination of a centrifugal governing mechanism mainly constituted of a flyweight unit connected to the driving shaft of the diesel engine and an electronic governing mechanism mainly constituted of an electromagnetic actuator including an electromagnetic coil and a plunger connected to a fuel control rack. In said electronic governing mechanism, the plunger is connected to the fuel control rack via a coupling means with a built-in Angleichung spring for adjusting the rate of fuel supply to a proper value in response to a change in the engine speed, while at high engine speeds said centrifugal governing mechanism is adapted for connection to said fuel control rack via a lever-rod coupling means to transmit the opening motion of the flyweight unit via said lever-rod coupling means to the fuel control rack thereby to move the fuel control rack in the fuel supply-decreasing direction.

Abstract: An anti-stall device for an internal combustion engine provided with a fuel injection pump having a fuel control rack and a governor mechanism connected to the fuel control rack and which has a speed control lever, comprising:a circuit for generating a dc voltage in proportion to the rotational speed of the engine;a circuit for comparing and amplifying an output voltage of the dc voltage generating circuit and a reference voltage corresponding to the idling speed of the engine;a timer circuit for receiving outputs of the comparing and amplifying circuit as inputs to generate outputs for a predetermined period of time; andan electromagnetic actuator for utilizing the outputs of the timer circuit to drive said fuel control rack in a fuel quantity increasing direction.