Patent classifications
B27B9/00
Handheld work apparatus
A handheld work apparatus has a drive motor which drives a work tool in rotation via a belt drive. The belt drive has at least one first, driving pulley and at least one second, driven pulley. Between the first pulley and the second pulley there acts at least one drive belt for transmitting the drive torque. A second pulley is connected to the tool for conjoint rotation. The rotational speed of the second pulley is less than the rotational speed of the first pulley during operation. The work apparatus has a brake unit which acts on the first pulley. The belt drive includes at least one redirection roll. During braking, at least one redirection roll bears on the tight side of each drive belt which acts between the first pulley and the second pulley. This allows a simple structure and safe braking of the work tool.
Handheld work apparatus
A handheld work apparatus has a drive motor which drives a work tool in rotation via a belt drive. The belt drive has at least one first, driving pulley and at least one second, driven pulley. Between the first pulley and the second pulley there acts at least one drive belt for transmitting the drive torque. A second pulley is connected to the tool for conjoint rotation. The rotational speed of the second pulley is less than the rotational speed of the first pulley during operation. The work apparatus has a brake unit which acts on the first pulley. The belt drive includes at least one redirection roll. During braking, at least one redirection roll bears on the tight side of each drive belt which acts between the first pulley and the second pulley. This allows a simple structure and safe braking of the work tool.
PORTABLE CUTTING MACHINE
A portable cutting machine allows a large battery pack to be attached on the rear of a handle unit without largely increasing the height of the handle unit. A portable cutting machine to which a battery pack having a connecting surface is attachable includes a base that comes in contact with a workpiece, a cutting machine body supported on an upper surface of the base and including a cutting blade protruding from a lower surface of the base to cut the workpiece, an electric motor that drives the cutting blade, and a handle unit grippable by a user, and a battery attachment portion located opposite to the cutting blade with respect to the handle unit to receive the battery pack attachable by sliding in a posture with the connecting surface facing sideward.
ELECTRIC WORKING MACHINE
An electric working machine in one aspect of the present disclosure includes: a motor; a driver to drive the motor; a first control circuit; and a second control circuit. The first control circuit controls the driver such that the motor rotates in a set rotation direction. The second control circuit is provided separately from the first control circuit. The second control circuit detects a rotation direction of the motor and performs an abnormality handling process to stop rotation of the motor in response to a situation where the detected rotation direction is reverse to the set rotation direction.
Electric power tool and method for manufacturing the same
A covering member made of a resin is integrally molded with a sensor substrate of a brushless motor in a circular saw by low-temperature, low-pressure injection molding. The covering member covers rotation detecting elements, a thermistor, resistors, and connecting portions (terminals) of lead wires that serve as electrically conductive portions conducting electric currents.
Electric power tool and method for manufacturing the same
A covering member made of a resin is integrally molded with a sensor substrate of a brushless motor in a circular saw by low-temperature, low-pressure injection molding. The covering member covers rotation detecting elements, a thermistor, resistors, and connecting portions (terminals) of lead wires that serve as electrically conductive portions conducting electric currents.
Electric working machine
An electric working machine of an example of the present disclosure includes: a motor; a power supply portion; a controller; and a voltage detector. The power supply portion generates a DC voltage to drive the motor by rectifying an AC voltage supplied from an AC power source and smoothing by a capacitor. The controller controls energization of the motor. The voltage detector detects the AC voltage. The controller is configured to interrupt the energization when the voltage detector does not detect the AC voltage.
CONTROLLER AND POWER TOOL INCLUDING THE SAME
A controller 50 that controls a power tool such as, for example, a portable circular saw includes a controller case 70 that houses an electric circuit board 60. Electric elements 61, 62 that generate heat and/or are to be cooled on the electric circuit board 60 contact a thick wall portion 73b of the controller case 70, resulting in heat dissipation resulting in effective cooling of the controller 50.
CUTTING TOOL
A cutting tool includes a rotary blade driven by a motor, a fixed blade disposed opposing the rotary blade, a housing holding the motor, and a battery mount part on a rear portion of the housing. The battery mount part has a guide groove that slidably receives a rail of a power tool battery pack. A blade cover is disposed partially around the rotary blade, and a portion or all of the blade cover has a shape in which the farther forward it goes the more it goes toward the side that has the fixed blade, viewed from the rotary blade. A base holds the fixed blade, and a portion or all of the base has a shape in which the farther forward it goes the more it goes toward the side that has the fixed blade, viewed from the rotary blade.
Technique for measuring electric current flowing in electric powered work machine
An electric powered work machine according to one aspect of the present disclosure includes: a tool; a motor; a manual switch; an electric current path; a shunt resistor; a reference voltage generation circuit; and an electric current measurement circuit. The reference voltage generation circuit (i) generates a reference voltage having a first magnitude in response to a first condition being established, and (ii) generates the reference voltage having a second magnitude in response to the first condition not being established. The electric current measurement circuit (i) receives the reference voltage and a measured voltage, and (ii) outputs an output voltage based on the reference voltage and the measured voltage.