Abstract: A trim operating lever device is disclosed which can downwardly or vertically swing a nozzle capable of adjusting the jet direction of jet water. When the trim operating lever is gripped with a finger of the hand which is gripping the steering handle, a lever of the lever lock means can be substantially simultaneously operated with the finger, to effect locking. Therefore, the number of operations by the left hand necessary for swinging the nozzle is reduced. Also, because the trim operating lever makes it possible to enlarge the operating force, the nozzle can be swung quickly.

Abstract: A temperature sensor circuit which includes: an adjustment circuit which generates a first divided voltage obtained by dividing a reference voltage; a current generation circuit which has a transistor element and generates a current corresponding to a gate voltage of the transistor element, the first divided voltage being supplied to a gate terminal of the transistor element; a voltage generation circuit which includes a diode element to which the current is supplied, an analog voltage being generated between both ends of the diode element; and an analog/digital (A/D) conversion circuit which compares a second divided voltage obtained by dividing the reference voltage with the analog voltage and converts the analog voltage into a digital value.

Abstract: An impeller drive shaft in a vessel is supported on a vessel body at a midsection thereof by a bearing member. A driven side coupler to be coupled with a drive side coupler on the side of an engine output shaft is mounted on a front end of the impeller driving shaft, a collar having a diameter larger than the maximum diameter D of the shaft is detachably mounted on the rear of the mounting portion for the driven side coupler on the impeller driving shaft, and the driven side coupler is fixed with respect to the shaft so as not to be capable of movement from axial thrust by an abutment between the collar and the driven side coupler. The collar may also be divided into two or more pieces with respect to the circumferential direction. The aforementioned arrangement improves durability of the shaft at the mounting portion for the driven side coupler and facilitates ease of maintenance.

Abstract: In a personal watercraft with an engine 17 disposed at a central portion of a craft body and a water jet propeller 18 disposed at a stem of the watercraft, a propeller shaft 33 of the water jet propeller is connected to an end 31 of a crankshaft of the engine by a shaft coupling 32. The shaft coupling as well as the ends of the crankshaft and propeller shaft are covered from the top and from both sides with a cover apparatus 22, including a first cover section 35 for removable attachment to the engine or the hull, and a second cover section section 36 for removable attachment to the first cover section. When the cover is removed, it only of the second cover section section, and even if the space for working is small, not much time is required for removal and re-attachment thereof.

Abstract: A bearing member for rotatably supporting a drive shaft for driving an impeller on a boat body configured to prevent wearing of an outside circumferential surface of a drive shaft and/or an inside circumferential surface of an inner lace. An inner lace makes contact with an outside circumferential surface of the drive shaft, and an outer lace is disposed on the outside of the inner lace with a rotary body dsiposed therebetween. A connecting member for rotating both the drive shaft and the inner lace is provided between the outside circumferential surface of the drive shaft and the inner lace. The connecting member is a ring-shaped elastic body pressed against the outside circumferential surface of the drive shaft and a side surface of the inner lace. Two bearing members are provided at an interval therebetween, and the connecting member is disposed between the bearing members.

Abstract: A power supply circuit for generating potentials used to drive a liquid crystal, has first to fourth switches (101 to 104) connected in series between a high potential line (105) and a low potential line (106). The first to fourth switches are turned on and off by a switch drive circuit (107) so that the period of time in which the first and third switches are on and the period of time in which the second and fourth switches are on alternate. The power'supply circuit also has the first to third capacitors (111 to 113) of which the state of connection is switched alternately between serial and parallel by the switching operation of the switches. The potential between the second and third switches converges the middle potential between the potentials of the high and low potential lines by the alternate switching between series and parallel connections of the third capacitor (113) to the first and second capacitors (111, 112).

Abstract: A drive shaft support structure for a boat for preventing water from penetrating a boat body via a cylindrical portion through which the drive shaft passes. The cylindrical portion extends inwardly from outside the boat toward the engine. A support portion for supports a rubber dampered bearing body, which rotatably supports the drive shaft on the engine side. The rubber dampered bearing body includes a rubber damper portion and a rubber cylindrical portion formed integrally with the rubber damper portion and extending toward the cylindrical portion. The rubber cylindrical portion and the cylindrical portion are directly connected. The rubber dampered bearing body supports the rear end of a cover for a coupler for connecting an output shaft of the engine and the drive shaft.

Abstract: To provide an exhaust structure for a jet propulsion watercraft which can simply achieve a reduction of the exhaust noise. In the exhaust structure for a jet propulsion watercraft, a water jet propeller is provided in a pump room of a watercraft body. An engine for driving the watercraft is connected to the water jet propeller. An exhaust opening of an exhaust pipe is attached to the engine and is exposed to a pump room. A resonator for sound deadening is provided for the exhaust pipe. Further, in the exhaust structure for a jet propulsion watercraft, the resonator is bent in a meandering state such that bent portions thereof are positioned adjacent to each other so that the entire resonator has a substantially flat plate-like configuration. The resonator having a plate-like configuration is laid along a ceiling wall of the pump room.

Abstract: A water jet propulsion apparatus is provided with an impeller rotatably disposed in a duct forming a channel. A waterproof seal is provided between a collar provided around an impeller shaft rotatably supported within the duct and coupled to the impeller and the stator. The collar is coupled to the impeller via the waterproof seal. The impeller shaft is screwed to the rear part of the impeller, and a drive shaft is spline-connected to the front part of the impeller. A rubber buffer for the rear end of the drive shaft is provided between the front end of the impeller shaft in the impeller and the rear end of the drive shaft. The peripheral portion of the buffer is formed in a shape such that air escapes from the impeller shaft side toward the drive shaft side when the impeller shaft is secured for preventing contact of water with the impeller shaft.

Abstract: A first and second circuits are connected in parallel between a first supply line supplying a first potential and a second supply line supplying a second potential. Each of the first and second circuits has first and second P-type transistors and an N-type transistor connected in series in order from the first-supply-line side. The gate of the first P-type transistor in the first circuit is connected to the drain of the N-type transistor in the second circuit. The gate of the first P-type transistor in the second circuit is connected to the drain of the N-type transistor in the first circuit. Input potentials opposite to each other are applied to the gates of the N-type transistors in the first and second circuits respectively and output potentials level-shifted from the input potentials are output from the drains of the N-type transistors in the first and second circuits respectively.

Abstract: A differential amplifier comprises first and second differential amplifier circuits. The first differential amplifier circuit includes a first N-type transistor and a second N-type transistor for constituting a differential pair, and operates based on a first input voltage VIN1. The second differential amplifier circuit includes a first P-type transistor and a second P-type transistor making up a differential pair, and operates based on a second input voltage VIN2. There is also provided a third P-type transistor operable based on a first signal S1 coming from the first differential amplifier circuit and a third N-type transistor operable based on a second signal S2 from the second differential amplifier circuit, wherein a voltage between these third P- and N-type transistors becomes an output voltage VOUT.

Abstract: An oil feed pump for feeding oil in an oil tank to an engine, an oil recovery pump for feeding oil in a crankcase into the oil tank, an oil drain pipe connected to the lower portion of the crankcase and extending upward, and an opening provided on top of the oil tank are provided in a lubrication system. An opening of the oil drain pipe opens at the position upward of the oil level in the crankcase at a moment when the oil in the oil tank is returned into the crankcase. A cap is provided with a dip stick. The engine can be mounted on a small planing boat with the crankshaft oriented in the fore-and-aft direction. The oil tank is integrally formed with the front portion of the engine so as to be elongated in the vertical direction and is formed with the opening on top. The aforementioned lubrication system enables oil changes to be performed easily.

Abstract: A water jet propulsion apparatus is provided with an impeller rotatably disposed in a duct forming a channel. A waterproof seal is provided between a collar provided around an impeller shaft rotatably supported within the duct and coupled to the impeller and the stator. The collar is coupled to the impeller via the waterproof seal. The impeller shaft is screwed to the rear part of the impeller, and a drive shaft is spline-connected to the front part of the impeller. A rubber buffer for the rear end of the drive shaft is provided between the front end of the impeller shaft in the impeller and the rear end of the drive shaft. The peripheral portion of the buffer is formed in a shape such that air escapes from the impeller shaft side toward the drive shaft side when the impeller shaft is secured for preventing contact of water with the impeller shaft.

Abstract: An impeller drive shaft in a vessel is supported on a vessel body at a midsection thereof by a bearing member. A driven side coupler to be coupled with a drive side coupler on the side of an engine output shaft is mounted on a front end of the impeller driving shaft, a collar having a diameter larger than the maximum diameter D of the shaft is detachably mounted on the rear of the mounting portion for the driven side coupler on the impeller driving shaft, and the driven side coupler is fixed with respect to the shaft so as not to be capable of movement from axial thrust by an abutment between the collar and the driven side coupler. The collar may also be divided into two or more pieces with respect to the circumferential direction. The aforementioned arrangement improves durability of the shaft at the mounting portion for the driven side coupler and facilitates ease of maintenance.

Abstract: A bearing body for rotatably supporting a drive shaft for driving an impeller on a watercraft body includes a bearing chamber containing bearing members rotatably supporting the drive shaft. Seal members are disposed on both sides of the bearing members and partition the bearing chamber by making contact with an outside circumferential surface of the drive shaft. The seal members are disposed so that grease in the bearing chamber does not leak out through the contact portions between the seal members and the outside circumferential surface of the drive shaft, and a breather passage is communicated with the bearing chamber. Two bearing members within the bearing chamber have a space formed between the bearing members, e.g., to form a grease reservoir between the bearing members. The aforementioned bearing structure reduces the necessity of maintenance, e.g., supplying grease to a drive shaft bearing portion, or at least the reduces the required frequency of maintenance.

Abstract: A bearing member for rotatably supporting a drive shaft for driving an impeller on a boat body configured to prevent wearing of an outside circumferential surface of a drive shaft and/or an inside circumferential surface of an inner lace. An inner lace makes contact with an outside circumferential surface of the drive shaft, and an outer lace is disposed on the outside of the inner lace with a rotary body dsiposed therebetween. A connecting member for rotating both the drive shaft and the inner lace is provided between the outside circumferential surface of the drive shaft and the inner lace. The connecting member is a ring-shaped elastic body pressed against the outside circumferential surface of the drive shaft and a side surface of the inner lace. Two bearing members are provided at an interval therebetween, and the connecting member is disposed between the bearing members.

Abstract: A semiconductor device comprises: a first resistor which has a plurality of first connection points to be selectively connected to an input terminal of an amplifier and has both ends to which a voltage is applied; and a second resistor which has one end to be connected to an output terminal of the amplifier and has a plurality of second connection points to be selectively connected to a feedback input terminal of the amplifier. One of the first connection points and one of the second connection points are selected in such a manner that a voltage at the output terminal of the amplifier becomes constant. Each of the first and second resistors is formed of first reference resistors having a first reference length and second reference resistors having a second reference length as many as needed, both of which are connected by an interconnect layer. The first and second reference resistors for forming the first and second resistors are provided in an effective resistor region and are regularly arranged.

Abstract: A drive shaft support structure for a boat for preventing water from penetrating a boat body via a cylindrical portion through which the drive shaft passes. The cylindrical portion extends inwardly from outside the boat toward the engine. A support portion for supports a rubber dampered bearing body, which rotatably supports the drive shaft on the engine side. The rubber dampered bearing body includes a rubber damper portion and a rubber cylindrical portion formed integrally with the rubber damper portion and extending toward the cylindrical portion. The rubber cylindrical portion and the cylindrical portion are directly connected. The rubber dampered bearing body supports the rear end of a cover for a coupler for connecting an output shaft of the engine and the drive shaft.

Abstract: A water jet propulsion apparatus having a duct forming a channel, an impeller disposed in the duct, a bearing of the impeller provided in the duct, and a cap closing the rear end of the bearing. In addition, at least one stream-straightening groove is formed in an external face of the cap. In the internal face of the duct, a stationary vane is formed in a portion facing toward the cap. Accordingly, a rotational component of a water stream close to the external face of a cap the bearing is substantially reduced, the size of the cap may be reduced, and cap position is not controlled by the position of the stationary vane.

Abstract: To provide an exhaust structure for a jet propulsion watercraft which can simply achieve a reduction of the exhaust noise. In the exhaust structure for a jet propulsion watercraft, a water jet propeller is provided in a pump room of a watercraft body. An engine for driving the watercraft is connected to the water jet propeller. An exhaust opening of an exhaust pipe is attached to the engine and is exposed to a pump room. A resonator for sound deadening is provided for the exhaust pipe. Further, in the exhaust structure for a jet propulsion watercraft, the resonator is bent in a meandering state such that bent portions thereof are positioned adjacent to each other so that the entire resonator has a substantially flat plate-like configuration. The resonator having a plate-like configuration is laid along a ceiling wall of the pump room.