Abstract: The present invention provides a handheld power tool and an operation method thereof. The handheld power tool comprises a housing, a handle, a switch, a motor, an output shaft and a working component; the working component comprises at least two working chucks; the at least two working chucks respectively comprise a working shaft, the handheld power tool further comprises a control mechanism locking the working component relative to the position of the housing, the control mechanism comprises a control part adjacent to the switch and movably disposed relative to the housing, and the control part operably removes the position locking of the working component and controls the output shaft to be dis-matched and disconnected with one of the working shafts; and the position conversion of the working chucks can be finished by means of other body parts of an operator through one hand, and the operation is convenient and reliable.

Abstract: An apparatus for delivering a fuel-air mixture to an engine is provided. The apparatus includes: a carburetor having one or more passages and one or more chambers, wherein at least some of the passages and chambers are in communication with one another; and a fluid pump communicated with the carburetor and pumping fluid into or out of the carburetor to influence an fuel-to-air ratio of a fuel and air mixture delivered from the carburetor.

Abstract: A carburetor for a two-stroke internal combustion engine whereby airtightness is maintained and intake of uncombusted fuel into an air path is prevented. The carburetor includes a circular cylindrical valve hole and a rotary valve fitted into the valve hole such that it can rotate and is disposed perpendicularly across a fuel intake path and an air intake path which are formed substantially parallel with respect to each other, and a fuel supply-side bore which controls the flow rate along the fuel intake path and the air supply-side bore which controls the air capacity along the air path pass through part of the cylindrical portion perpendicularly to the axial direction of the rotary valve, and annular recesses formed in part of a circumferential wall of an outer circumference of the rotary valve so as not to correspond to at least the fuel supply-side bore and the air supply-side bore.

Abstract: A carburetor comprises a rotation-typed control valve which opens or closes a second bleed air passage according to an opening degree of the throttle valve. The control valve includes an upper end portion of a valve stem, and in a projection plane orthogonal to an axis of an aspirating channel, a first bleed air passage is arranged on one side of the valve stem, an upstream-side passage portion starting from the control valve of the second bleed air passage is arranged on an upper side of the aspirating channel, a downstream-side passage portion starting from the control valve of the second bleed air passage is arranged on the one side of the valve stem, and a downstream end of the downstream-side passage portion is connected to a midway portion of the first bleed air passage.

Abstract: A carburetor includes a body with an air intake path, a fuel pump and a fuel pressure regulator. The fuel pump and fuel pressure regulator are positioned on the same side of the body. A fuel pump and metering chamber diaphragm is sandwiched between the body of the carburetor and a pump body and cover. The diaphragm separates a pump chamber from a pulse chamber of the fuel pump and separates a fuel chamber from an air chamber in the fuel pressure regulator. Inlet and outlet flapper valves are part of the diaphragm or a separate flapper valve member positioned between the body and the diaphragm.

Abstract: In at least one implementation a carburetor includes an intake bore with a port opening into the intake bore, a fuel chamber from which fuel is supplied to the intake bore, and an accelerator device including a fuel reservoir. A fuel flow control valve is provided between the fuel chamber and the port to control the flow rate of fuel to the port and at least one passage communicates the fuel reservoir with the port and fuel in the fuel reservoir is supplied to the port therethrough. The passage also communicates the fuel reservoir with the fuel chamber. The fuel flow control valve is located between the fuel reservoir and the port and between the fuel chamber and the port, and the passage includes a portion extending between the fuel reservoir and the fuel chamber independently of the fuel flow control valve.

Abstract: A carburetor includes a main fuel path connected to a main nozzle and a slow fuel path connected to a slow port. The main fuel path and the slow fuel path are separated from each other and are independently communicated to a constant fuel chamber below a fuel level of the fuel chamber. The slow fuel path includes a first slow jet located above the fuel level and a second slow jet located in the downstream of the first slow jet. A opening size of the second slow jet is smaller than that of the first slow jet, and the first and second slow jets are arranged in series.

Abstract: In at least some implementations, a valve for a carburetor that is moveable between open and closed positions includes a first valve portion adapted to at least substantially inhibit a first fluid flow in the carburetor when the valve is closed and a second valve portion associated with the first valve portion to at least substantially inhibit a second fluid flow in the carburetor when the valve is closed. In this way, two fluid flows may be at least substantially inhibited at the same time by the valve. In some forms, the fluid flows may include a primary fluid flow to an engine and a secondary fluid flow, such as from an accelerator pump, to the engine.

Abstract: Disclosed is an engine fuel supply apparatus which can be made smaller in size and in which the amount of fuel in an air-fuel mixture can be increased with a fast response in correspondence with the operation of a throttle valve when the engine is accelerated rapidly. The fuel supply apparatus is provided with a fuel booster pump. A portion of an air-fuel mixture is introduced into a negative-pressure chamber of the fuel booster pump via a negative-pressure chamber channel, and the fuel booster pump is actuated. The actuation forces air in a pump chamber to flow into a pressure chamber, and fuel in a fuel storage chamber is temporarily supplied to a carburetor.

Abstract: In the carburetor 1A with the acceleration pump of the present embodiment, when a plunger 16 is stopped at the position of a top dead center in a cylinder 10 and the acceleration pump mechanism is not operated as in an idle operation or the like, a gap w having a predetermined width is formed between the tip of a rod 14A and a rod abutment face 16a of the plunger 16, whereby an operational error generated in a link system which transmits the opening/closing operation of a throttle valve to the rod is eliminated through this gap.

Abstract: According to one implementation, a carburetor includes an intake bore, a throttle valve, a main fuel nozzle, an accelerator device and a fuel passage. The throttle valve is movable between an idle and wide open positions and includes a shaft rotatably supported around an axial line extending across the intake bore. The accelerator device may be operable to increase an amount of fuel that flows through the main fuel nozzle when the throttle valve is moved toward its wide open position, and may include a fuel reservoir constructed and arranged to store fuel. The fuel passage communicates with the main fuel nozzle and the fuel reservoir is provided upstream of the main fuel nozzle such that fuel flows through the fuel reservoir before being delivered to the main fuel nozzle.

Abstract: A straight bore butterfly valve carburetor with accelerator assist module includes a butterfly valve carburetor with a straight bore and a vacuum accelerator assist module. The butterfly valve carburetor with a straight bore includes a substantially straight bore intake chamber. The venturi in the intake chamber is eliminated. The vacuum accelerator assist module includes two housing halves, a diaphragm and means for biasing the diaphragm into the fuel chamber. The diaphragm creates a vacuum chamber and a fuel chamber. The vacuum chamber communicates with the substantially straight bore intake chamber and the fuel chamber communicates with a fuel metering chamber of the carburetor. A vacuum is applied to the diaphragm at engine idle, which overcomes the means for biasing. When the butterfly valve is opened, the vacuum collapses and fuel is feed into the substantially straight bore intake chamber to increase engine speed.

Abstract: An accelerator pump cap for an accelerator pump assembly of a carburetor, such as a motorcycle or ATV carburetor, has a cap body with a base and a sidewall projecting from the base defining a fuel chamber within the cap body beneath an open top. Preferably, one or more ports extend through the sidewall closely-spaced to the open top of the cap body to ensure that any vapor or gas residing within the fuel chamber is flushed out of the fuel chamber through the port or ports when the accelerator pump assembly is actuated to supply fuel to the carburetor. Accelerator pump assemblies and the use of a separate collector ring within an accelerator pump cap are also provided.

Abstract: A carburetor of an internal combustion engine for operating a manually-guided implement, including an intake channel having a venturi section for combustion air, a fuel channel that opens into the intake channel via a fuel opening, and an accelerator pump that is in flow-conducting communication with the fuel opening. During operation of the carburetor, the fuel channel is adapted to have fuel flow continuously therethrough. The fuel channel is guided through a pump chamber of the accelerator pump.

Abstract: A carburetor includes a fuel and air mixing passage with a throttle valve therein, and a bore with a valve therein defining in part a valve actuation chamber and a separate fuel and air mixing chamber in communication with the fuel and air mixing passage at a location downstream of the throttle valve. A fuel passage and an air passage are in communication with the fuel and air mixing chamber. A purge apparatus is in communication with the valve actuation chamber and is operable to move the valve to an open position to open the fuel and air passages to the fuel and air mixing chamber such that a fuel and air mixture may flow from the fuel and air mixing chamber to the fuel and air mixing passage downstream of the throttle valve.

Abstract: According to one implementation, carburetor includes an intake bore, a throttle valve, a main fuel nozzle, an accelerator device and a fuel passage. The throttle valve is movable between an idle and wide open positions and includes a shaft rotatably supported around an axial line extending across the intake bore. The accelerator device may be operable to increase an amount of fuel that flows through the main fuel nozzle when the throttle valve is moved toward its wide open position, and may include a fuel reservoir constructed and arranged to store fuel. The fuel passage communicates with the main fuel nozzle and the fuel reservoir is provided upstream of the main fuel nozzle such that fuel flows through the fuel reservoir before being delivered to the main fuel nozzle.

Abstract: An accelerator assist module for carburetors includes two housing halves, a diaphragm and means for biasing the diaphragm. Each housing half includes a peripheral flange, a cavity and a pipe extension. The peripheral flange of each housing half preferably includes means for securing thereof to the opposing housing half. The diaphragm creates a vacuum chamber and a fuel chamber. The means for biasing forces the diaphragm into the fuel chamber. The vacuum chamber communicates with an intake chamber of a carburetor and the fuel chamber communicates with a fuel metering chamber of the carburetor. A vacuum is applied to the diaphragm at engine idle, which overcomes the means for biasing. When a butterfly valve of the carburetor is opened, the vacuum collapses and air inside the fuel cavity is displaced into the fuel metering chamber and fuel into the intake chamber to increase engine speed.

Abstract: A priming and purging fuel system for an internal combustion engine purges a diaphragm carburetor of the engine of stale liquid fuel and accumulated fuel vapor and air while simultaneously priming the carburetor and/or engine with liquid fuel for starting. A start pump of the fuel system supplies at least liquid fuel to a priming circuit and preferably at least fuel vapor and air to a purging circuit of the fuel system. The priming circuit delivers the priming fuel to the engine via a conduit that leads to an isolation chamber located between an inlet jet and preferably an outlet jet. The cross sectional flow area of the jets are appropriately sized to flow a needed amount of priming fuel to the carburetor and/or engine for starting without flooding the engine. The combination of the enlarged isolation chamber and jets, at least substantially prevents fuel dribble from the priming circuit and into the engine while running.

Abstract: To optimize an accelerator pump while maintaining serviceability of a carburetor. A drive lever includes an operating portion that slides in abutment along a cam projection formed on a cam and a transmitting portion for transmitting a swinging force in an increased magnitude by being provided in the vicinity of a spindle as a lever swing axis in comparison with the operating portion. A driven lever includes a receiving portion being capable of a swinging motion together with the drive lever about the spindle and receiving the swinging force by being in abutment with the transmitting portion and a connecting portion connected to an accelerator pump as a control unit thereof for controlling the flow amount of fuel are provided and the transmitting portion includes a screw mechanism for adjusting the angle formed between the drive lever and the driven lever and a cylindrical cover for covering the screw mechanism.

Abstract: A membrane carburetor (1) has a control chamber (13) which is connected via at least one fuel opening (9, 10) to an intake channel (3). The control chamber (13) is delimited by a control membrane (14). A fuel line (54) opens into the control chamber (13) via an inlet valve (15). The inlet valve (15) opens in dependence upon the deflection of the control membrane (14). The membrane carburetor (1) has an acceleration pump (30) which is actuated in dependence upon the position of a throttle element held in the intake channel (3). A good acceleration enrichment and a stable running of the internal combustion engine are achieved when the acceleration pump (30) operates hydraulically on at least one actuating member in the control chamber (13).

Abstract: A membrane carburetor (1) has a control chamber (13) which is connected via at least one fuel opening (9, 10) to an intake channel (3). The control chamber (13) is delimited by a control membrane (14). A fuel line (54) opens into the control chamber (13) via an inlet valve (15). The inlet valve (15) opens in dependence upon the deflection of the control membrane (14). The membrane carburetor (1) has an acceleration pump (30) which is actuated in dependence upon the position of a throttle element held in the intake channel (3). A good acceleration enrichment and a stable running of the internal combustion engine are achieved when the acceleration pump (30) operates hydraulically on at least one actuating member in the control chamber (13).

Abstract: The accelerator apparatus prevents air from remaining within a pump chamber and discharged fuel vapor from causing a pumping effect so as to a destabilize engine operation and increase of an exhaust gas content of harmful material, in an accelerator apparatus in which an accelerated fuel passage draws and discharges fuel to the pump chamber of an accelerator pump, which is connected to a main fuel passage. The pump chamber of the accelerator pump is mechanically coupled with a throttle valve and is connected to a fixed fuel chamber storing a fuel delivered to an intake passage at a fixed pressure by the accelerated fuel passage. Air remaining within the pump chamber and a fuel vapor generated within the pump chamber are discharged to the fixed fuel chamber, and fuel extruded from the pump chamber due to a pumping effect of the remaining air and the fuel vapor enters into the fixed fuel chamber, thereby preventing the alteration of a rate of the fuel flowing through a main fuel passage.

Abstract: An accelerated fuel passage of an accelerator pump operatively connected with a throttle shaft having a throttle valve. The accelerated fuel passage is connected to an upstream side of a needle orifice, which orifice is coupled to a main nozzle. Consequently, the fuel is discharged by the accelerator pump into an area before the needle orifice. By the addition of a one-way check valve system in a fuel pick up at a metering chamber for a fuel circuit, the fuel driven by the accelerator pump piston is discharged to a venturi tube of an intake passage through the main nozzle. A self pumping effect caused by an engine pulsation is dampened or eliminated by the needle orifice. Further, a check valve is provided within a fuel pick up at a metering chamber for a fuel circuit, whereby the fuel driven by the accelerator pump piston is discharged to a venturi tube through a main nozzle without returning to the fixed fuel chamber.

Abstract: A combustion engine carburetor with a fuel-and-air mixing passage extending through a body and a float bowl engaged sealably to the body. A vacuum actuated acceleration fuel pump is preferably carried by the float bowl and has a hose-less vacuum channel communicating between the fuel-and-air mixing passage downstream of a throttle valve and a vacuum chamber of the acceleration pump. A hose-less fuel discharge channel communicates between a supplemental fuel chamber of the acceleration pump and the fuel-and-air mixing passage between a venturi and a choke valve in the mixing passage. Preferably, the fuel discharge channel has an injecting bore portion defined by the body and being angled to direct fuel in a downstream direction toward the venturi to promote mixing with air.

Abstract: To inhibit an after burn phenomenon, an accelerating apparatus (P) is sectioned into a pump chamber (23) and a pressure receiving chamber (24) by a partition body (20), an acceleration fuel intake path (25) and an acceleration fuel discharge path (28) are open to the pump chamber (23), and a fuel discharge path (30b) is open to a float chamber (8), a negative pressure introducing path (30a) is open to the pressure receiving chamber (24), a pump spring (31) is provided compressedly in the pressure receiving chamber (24), and a valve body (34) is formed by a jet opening and closing valve portion (34a) opening and closing an opening portion (6a) of a main fuel jet (6) when an engine operates and stops respectively by a solenoid apparatus (S), and a discharge path opening and closing valve portion (34b) opening and closing the fuel discharge path (30b) when an engine stops and operates respectively, and synchronously moves with a movable core (17) of the solenoid apparatus (S).

Abstract: A carburetor for an internal combustion engine includes an intake channel section (2) as well as a throttle element journalled in the intake channel section (2). The throttle element is adjustable between a full-load position (25) and an idle position (26). A pump (20, 30) is provided for additional fuel metering and this pump includes a pumping chamber (24, 34) and a pump piston (21, 31) guided in the pumping chamber (24, 34). The position of the pump piston (21, 31) is coupled to the position of the throttle element. To ensure an optimal supply of the internal combustion engine with fuel in each operating state, the pump piston (21, 31) is so coupled to the throttle element that fuel is pumped from the pumping chamber (24, 34) into the intake channel section (2) when there is a displacement of the throttle element from the full throttle position (25) into the idle position (26).

Abstract: An accelerator for a carburetor that is linked to a throttle valve and allows a piston-type accelerator pump to be operated in a simple configuration that dispenses with a link mechanism and does not greatly enlarge the carburetor. The lower surface of a throttle valve lever (10) is provided with a cam (33) that has a circular shape centered about a throttle valve stem (8) and is configured such that the cam surface (33A) thereof faces a carburetor main body (1). An accelerator pump (25) is placed parallel to the throttle valve stem (8) and the upper end of a piston rod (28) thereof is brought into contact with the cam surface (33A). The cam (33) pushes the piston rod (28) down as the throttle valve lever (10) swings in the opening direction of the throttle valve, and the acceleration fuel in the pump chamber (29) is delivered and supplied to the suction channel (2).

Abstract: The invention relates to a carburetor arrangement of a portable handheld work apparatus and includes a carburetor (1), an accelerator pump (2) and a venting pump (3). The venting pump (3) acts on the accelerator pump (2) via a venting line (4). A check valve (5) is mounted in the venting line (4) in such a manner that its outlet end (6) is directed in the direction of the venting pump (3). A pretensioning device (7) is provided which holds a valve body (8) of the check valve (5) closed below a selected difference pressure between the outflow end (6) and an opposite-lying inflow end (9). A support device (10) which acts on the valve body (8) and is actuable, at one end, by pressure at the outflow end (6) without considering pressure at the other end (9) or by pressure on the inflow end (9) without considering the pressure on the other end (6).

Abstract: An accelerator for a carburetor that is linked to a throttle valve and allows a piston-type accelerator pump to be operated in a simple configuration that dispenses with a link mechanism and does not greatly enlarge the carburetor. The lower surface of a throttle valve lever 10 is provided with a cam 33 that has a circular shape centered about a throttle valve stem 8 and is configured such that the cam surface 33A thereof faces a carburetor main body 1. An accelerator pump 25 is placed parallel to the throttle valve stem 8 and the upper end of a piston rod 28 thereof is brought into contact with the cam surface 33A. The cam 33 pushes the piston rod 28 down as the throttle valve lever 10 swings in the opening direction of the throttle valve, and the acceleration fuel in the pump chamber 29 is delivered and supplied to the suction channel 2.

Abstract: A carburetor arrangement is provided for an internal combustion engine of a manually guided implement, and includes a carburetor that is embodied in particular as a diaphragm carburetor. A butterfly valve is pivotably mounted in an air channel that is disposed in the carburetor and leads to the internal combustion engine. Also provided is an accelerator pump that includes a pump chamber and an accelerator piston that is guided in the pump chamber. The accelerator piston is coupled with the butterfly valve. The pump chamber can be connected with a fuel tank via a pump line. A first pressure-controlled check valve is provided in the pump line.

Abstract: A membrane carburetor for an internal combustion engine in a portable handheld work apparatus includes a control chamber (3) delimited by a membrane (2). The control chamber (3) is connected via a feed line (4) to a fuel tank (5). The feed line (4) is cleared via a valve body (6) when there is a deflection of the membrane (2) because of an underpressure in the control chamber (3). The control chamber (3) is connected to an air channel (10) via at least one fuel nozzle (7) and at least one ancillary chamber (9). The air channel (10) passes through the membrane carburetor (1) and leads to the internal combustion engine. A purge pump (11) is provided in a fuel line (12) connecting the control chamber (3) to the fuel tank (5). The fuel path between the control chamber (3) and the purge pump (11) is guided through at least one ancillary chamber (9).

Abstract: An acceleration device of a carburetor for a two cycle engine with a rotary dual valve which controls air flow through both a scavenging passage and a separate air intake passage each extending through a carburetor body. The carburetor body houses a metering fuel chamber and an air reference chamber defined by a diaphragm between them. Fuel in the metering fuel chamber is discharged through a port into the air intake passage. An acceleration pump has an actuation chamber which communicates with the scavenging passage and a pump chamber which communicates with the air reference chamber and a membrane between them. During engine acceleration the membrane is displaced by a pressure introduced into the actuation chamber to forcibly send air into the air reference chamber from the pump chamber to move, the diaphragm into the metering fuel chamber, and thereby increase the fuel delivered to the air intake passage.

Abstract: This invention is directed to a dual barrel carburetor for a motorcycle. The preferred carburetor includes a novel combination of a fuel bowl assembly, a metering assembly, a main body assembly, and an air plenum assembly. The dual barrel carburetor includes annular discharge booster venturis associated with a main fuel delivery circuit. An idle circuit opens downstream of the throttle plates. A transfer circuit discharge port is positioned across the throttle plates. The combination of the idle, transfer and main fuel circuits ensures the smooth delivery of fuel throughout all operating conditions of the motorcycle engine. The plenum manifold assembly includes a pair of air passages in fluid communication with one another to permit a final opportunity to optimize the fuel delivery to the respective combustion chambers.

Abstract: A carburetor arrangement is provided for an internal combustion engine of a manually guided implement, and includes a carburetor that is embodied in particular as a diaphragm carburetor. A butterfly valve is pivotably mounted in an air channel that is disposed in the carburetor and leads to the internal combustion engine. Also provided is an accelerator pump that includes a pump chamber and an accelerator piston that is guided in the pump chamber. The accelerator piston is coupled with the butterfly valve. The pump chamber can be connected with a fuel tank via a pump line. A first pressure-controlled check valve is provided in the pump line.

Abstract: A membrane carburetor for an internal combustion in a portable handheld work apparatus includes a control chamber (3) delimited by a membrane (2). The control chamber (3) is connected via a feed line (4) to a fuel tank (5). The feed line (4) is cleared via a valve body (6) when there is a deflection of the membrane (2) because of an underpressure in the control chamber (3). The control chamber (3) is connected to an air channel (10) via at least one fuel nozzle (7) and at least one ancillary chamber (9). The air channel (10) passes through the membrane carburetor (1) and leads to the internal combustion engine. A purge pump (11) is provided in a fuel line (12) connecting the control chamber (3) to the fuel tank (5). The fuel path between the control chamber (3) and the purge pump (11) is guided through at least one ancillary chamber (9).

Abstract: The invention provides an inexpensive acceleration apparatus of a carburetor which can stably supply a fuel for acceleration for a long time. In the acceleration apparatus of the carburetor, a cam lever (8) provided with a cam surface (8A) is fixed to a throttle valve operating shaft (4A) disposed between a throttle lever (5) and an end portion (3A) of a supporting boss (3). A first lever (10) is brought into contact with the cam surface (8A) of the cam lever by a first spring (12) for urging in a first rotational direction (A). A second lever (11) is brought into contact with a restriction portion (10C) of the first lever (10) by a second spring (13) for urging in a second rotational direction (B), and is arranged in such a manner as to be brought into contact with a pump rod (6H) for pressing a pump diaphragm (7) of a pump apparatus (P).

Abstract: A carburetor for an internal combustion engine with an accelerator fuel pump in the carburetor having a piston actuated by a cam on a throttle valve shaft and a ball between them. The axis of a pump chamber in which the piston is slidably received is offset from and eccentric to the axis of rotation of the throttle shaft so that little fuel is supplied to the operating engine by the accelerator pump as the shaft is rotated to move the throttle valve from its idle position to an intermediate position and most of the fuel supplied by the accelerator pump to the engine is delivered as the shaft is rotated to move the throttle valve from the intermediate position to its wide open throttle position.