Abstract: A chain saw may include a saw chain, a guide bar to which the saw chain is attached, a sprocket configured to run the saw chain along a periphery of the guide bar, a prime mover configured to rotate the sprocket, an oil tank configured to store oil to be supplied to the saw chain, a housing that houses the prime mover and the oil tank, a bolt protruding from the housing and penetrating a hole disposed in the guide bar, a nut screwed onto the bolt to fix the guide bar to the housing, and a heat dissipating structure configured to dissipate heat from the bolt to the oil in the oil tank.

Abstract: A cam member includes an intermediate disk, a first eccentric cam disposed on an upper surface of the intermediate disk and connected to a first blade and a second eccentric cam disposed on a lower surface of the intermediate disk and connected to a second blade. A center of gravity of the first eccentric is positioned in a first direction from a rotation axis of the cam member. A center of gravity of the second eccentric cam is positioned in a second direction opposite to the first direction from the rotation axis. A center of gravity of an upper half of the intermediate disk is positioned in the second direction from the rotation axis. A center of gravity of lower half of the intermediate disk is positioned in the first direction from the rotation axis.

Abstract: A gardening trimmer may include: a first blade connected to a first cam member and configured to reciprocate in response to rotation of the first cam member; and a second com connected to a second cam member and configured to reciprocate in opposite phase to the first blade in response to rotation of the second cam member. The first cam member includes a first eccentric cam configured to revolve around a first rotation axis and is connected to the first blade at the first eccentric cam. The second cam member includes a second eccentric cam configured to revolve around a second rotation axis and is connected to the second blade at the second eccentric cam. Each of the first and second blades is configured to reciprocate along a plane including the first and second rotation axis.

Abstract: A chain saw may include a saw chain, a guide bar to which the saw chain is attached, a sprocket configured to run the saw chain along a periphery of the guide bar, a prime mover configured to rotate the sprocket, an oil tank configured to store oil to be supplied to the saw chain, a housing that houses the prime mover and the oil tank, a bolt protruding from the housing and penetrating a hole disposed in the guide bar, a nut screwed onto the bolt to fix the guide bar to the housing, and a heat dissipating structure configured to dissipate heat from the bolt to the oil in the oil tank.

Abstract: A handcart may include: a front wheel; a rear wheel; a support frame supporting the front wheel and the rear wheel; a receptacle pivotable relative to the support frame; a load sensor configured to detect a load applied to the rear wheel; and a control unit. When the load detected by the load sensor is less than or equal to a predetermined load, the control unit may be configured to determine that the rear wheel is predicted to lift from a ground.

Abstract: A gardening trimmer may include: a first blade connected to a first cam member and configured to reciprocate in response to rotation of the first cam member; and a second com connected to a second cam member and configured to reciprocate in opposite phase to the first blade in response to rotation of the second cam member. The first cam member includes a first eccentric cam configured to revolve around a first rotation axis and is connected to the first blade at the first eccentric cam. The second cam member includes a second eccentric cam configured to revolve around a second rotation axis and is connected to the second blade at the second eccentric cam. Each of the first and second blades is configured to reciprocate along a plane including the first and second rotation axis.

Abstract: To provide a handle that is effective at achieving both vibration resistance and usability. A handle attached to a tool body of a power tool has: a grip portion; a connecting portion that connects to the tool body; elastic element interposing regions that are formed between the grip portion and the connecting portion; elastic elements disposed in the elastic element interposing regions; a powder filling region formed between the grip portion and connecting portion; and a plurality of powder bodies that fill the powder filling region.

Abstract: A working machine according to one aspect of the present disclosure includes a main body portion, a driving device, a working tool, a grip portion and a determiner. The grip portion is attached to the main body portion and configured to be held by a user of the working machine. The determiner is configured to determine an abnormal state of the working machine when a couple moment received by the user through the grip portion exceeds a couple threshold. The couple threshold is 200 N·m per 50 ms.

Abstract: To provide a handle that is effective at achieving both vibration resistance and usability. A handle attached to a tool body of a power tool has: a grip portion; a connecting portion that connects to the tool body; elastic element interposing regions that are formed between the grip portion and the connecting portion; elastic elements disposed in the elastic element interposing regions; a powder filling region formed between the grip portion and connecting portion; and a plurality of powder bodies that fill the powder filling region.

Abstract: An improved hand-held power tool is provided which can effectively reduce whirling vibration caused by imbalance of a rotating element. The power tool has a grip that is connected to a tool body and designed to be held by a user and a self-synchronous mechanism that reduces whirling vibration caused in the tool body or the grip when the tool bit is driven. The self-synchronous mechanism is of a phase variable type, having a rotating body which serves as a vibrator and is rotationally driven by a driving source different from a driving source for the tool bit. The self-synchronous mechanism is disposed in the tool body or the grip in which whirling vibration is caused, and arranged such that a phase of vibration of the rotating body is automatically tuned to a phase of the whirling vibration, thereby reducing the whirling vibration.

Abstract: It is an object of the invention to provide an effective technique for a motor support structure of a power tool to reduce vibration. A representative reciprocating power tool may include a tool body, a tool bit, a grip, a motor, a tool bit side bearing, a grip side bearing, a tool bit side bearing housing, a grip and an elastic element. The tool bit side bearing housing houses the tool bit side bearing, while the grip side bearing housing houses the grip side bearing. The elastic element is disposed between the grip side bearing housing and the grip wherein the grip side bearing housing is elastically supported by the grip via the elastic element. According to the invention, because the grip is adapted to support the grip side bearing housing via the elastic element and the rigidity of the grip side bearing housing can be increased and vibration of the grip side bearing housing can be reduced.

Abstract: An improved hand-held power tool is provided which can effectively reduce whirling vibration caused by imbalance of a rotating element. The power tool has a grip that is connected to a tool body and designed to be held by a user and a self-synchronous mechanism that reduces whirling vibration caused in the tool body or the grip when the tool bit is driven. The self-synchronous mechanism is of a phase variable type, having a rotating body which serves as a vibrator and is rotationally driven by a driving source different from a driving source for the tool bit. The self-synchronous mechanism is disposed in the tool body or the grip in which whirling vibration is caused, and arranged such that a phase of vibration of the rotating body is automatically tuned to a phase of the whirling vibration, thereby reducing the whirling vibration.

Abstract: It is an object of the invention to provide an effective technique for a motor support structure of a power tool to reduce vibration. A representative reciprocating power tool may include a tool body, a tool bit, a grip, a motor, a tool bit side bearing, a grip side bearing, a tool bit side bearing housing, a grip and an elastic element. The tool bit side bearing housing houses the tool bit side bearing, while the grip side bearing housing houses the grip side bearing. The elastic element is disposed between the grip side bearing housing and the grip wherein the grip side bearing housing is elastically supported by the grip via the elastic element. According to the invention, because the grip is adapted to support the grip side bearing housing via the elastic element and the rigidity of the grip side bearing housing can be increased and vibration of the grip side bearing housing can be reduced.

Abstract: A vibration proofing property is provided in a backpack power tool. A backpack power tool has a backpack carrying part 103 which can be carried on user's back, and a tool body 105 mounted on the backpack carrying part 103. Elastic members 133, 135 are provided which connect the tool body 105 and a body support region 113 of the backpack carrying part 103. The elastic members 133, 135 deform by receiving the weight of the tool body 105 and vibration which is caused in the tool body 105 by rotation of the rotator 123, and thereby reduce transmission of the vibration from the tool body 105 to the backpack carrying part 103.

Abstract: It is an object of the invention to provide an effective technique for a motor support structure of a power tool to reduce vibration. A representative reciprocating power tool may include a tool body, a tool bit, a grip, a motor, a tool bit side bearing, a grip side bearing, a tool bit side bearing housing, a grip and an elastic element. The tool bit side bearing housing houses the tool bit side bearing, while the grip side bearing housing houses the grip side bearing. The elastic element is disposed between the grip side bearing housing and the grip wherein the grip side bearing housing is elastically supported by the grip via the elastic element. According to the invention, because the grip is adapted to support the grip side bearing housing via the elastic element and the rigidity of the grip side bearing housing can be increased and vibration of the grip side bearing housing can be reduced.

Abstract: It is accordingly an object of the invention to provide a technique of cooling a power tool which further improves cooling effectiveness of the power tool. According to the invention, a power tool is provided that includes a driving motor, a tool bit, a power transmitting mechanism, a tool body and a cooling fan. The power tool further includes first and second cooling air passages. The first cooling air passage is disposed within the tool body and flows cooling air into the tool body by using the cooling fan. The second cooling air passage is provided within the tool body and takes outside air into the tool body by using the flow of the cooling air through the first cooling air passage. The cooling air within the first cooling air passage can be cooled by mixing outside air taken into the tool body via the second cooling air passage and therefore, the cooling air can further effectively cool components within the power tool. As a result, cooling effectiveness of the power tool can be improved.

Abstract: It is an object of the invention to provide an effective technique for a motor support structure of a power tool to reduce vibration. A representative reciprocating power tool may include a tool body, a tool bit, a grip, a motor, a tool bit side bearing, a grip side bearing, a tool bit side bearing housing, a grip and an elastic element. The tool bit side bearing housing houses the tool bit side bearing, while the grip side bearing housing houses the grip side bearing. The elastic element is disposed between the grip side bearing housing and the grip wherein the grip side bearing housing is elastically supported by the grip via the elastic element. According to the invention, because the grip is adapted to support the grip side bearing housing via the elastic element and the rigidity of the grip side bearing housing can be increased and vibration of the grip side bearing housing can be reduced.

Abstract: It is accordingly an object of the invention to provide a technique of cooling a power tool which further improves cooling effectiveness of the power tool. According to the invention, a power tool is provided that includes a driving motor, a tool bit, a power transmitting mechanism, a tool body and a cooling fan. The power tool further includes first and second cooling air passages. The first cooling air passage is disposed within the tool body and flows cooling air into the tool body by using the cooling fan. The second cooling air passage is provided within the tool body and takes outside air into the tool body by using the flow of the cooling air through the first cooling air passage. The cooling air within the first cooling air passage can be cooled by mixing outside air taken into the tool body via the second cooling air passage and therefore, the cooling air can further effectively cool components within the power tool. As a result, cooling effectiveness of the power tool can be improved.