Please select the most similar patent number from A, B, C and D. Which number is?
A power tool (10), comprising a working head (15), a motor (11), a casing (13), and a handle (12). The motor comprises a motor shaft defined with a central axis, and the motor shaft drives the working head to effect the functions of the power tool. The casing is used to contain or secure the motor. The handle is held by a user and comprises a handle housing. The handle housing is made of a first material and is provided with a receiving cavity. The power tool further comprises a handle self-vibration absorption device (16). The handle self-vibration absorption device comprises one handle self-vibration absorber. The handle self-vibration absorber is made of a second material different from the first material. The weight of the handle self-vibration absorber is less than the weight of the handle housing. The density of the handle self-vibration absorber is greater than or equal to 1 g/cm3 or is greater than the density of the handle housing. The size of the handle self-vibration absorber in the direction of the central axis is less than the size of the handle housing in the direction of the central axis, and the handle self-vibration absorber is at least partially located in the receiving cavity. The power tool has minimal vibration and is comfortable to hold.
A: A master manipulator manipulation device for a robot. The master manipulator manipulation device comprises: a puncture assembly (110), the puncture assembly (110) comprising a handle housing, a puncture execution mechanism movably arranged on the handle housing, and a force feedback mechanism arranged at the bottom of the handle housing, the force feedback mechanism being connected to the puncture execution mechanism, and the force feedback mechanism applying resistance to the puncture assembly on the basis of puncture force feedback information; and a posture adjustment component (120) and a base (130). Further disclosed is a robot, comprising a puncture needle arranged at a terminal end of a mechanical arm, and the master manipulator manipulation device. The master manipulator manipulation device can control the needle insertion operation of the terminal end of the mechanical arm and feed back the needle insertion resistance at the terminal end of the mechanical arm.
B: A blower (100), comprising: a motor (110); a fan (120), being driven by the motor (110) to rotate about a central axis (101); a battery pack (130), for supplying power to the motor (110); an air duct assembly (140), forming an air inlet (141) for air intake and an air outlet (142) for air outlet; and further comprising: a first handle (150), forming a first holding portion (151) for holding; and a second handle (160), forming a second holding portion (161) for holding. At least part of projection of the battery pack (130), in the radial direction of the central axis (101), on a plane (102) passing through the central axis (101) is located between the first handle (150) and the second handle (160). The blower (100) facilitates reducing the burden when a user uses the blower (100).
C: Provided is a back-traveling self-propelled work machine, comprising: a main machine (12), comprising a travel assembly (121) and a drive motor (122) for driving the travel assembly (121); an operation switch (112c), connected to the drive motor (122); a handle apparatus (11), connected to the main machine (12); the handle apparatus comprises: an operation member (112), comprising a grip part for a user to grip; a connecting rod (111), connected to the main machine (12); a sensing module (14), used for sensing the pushing force applied to the handle apparatus (11) to drive the back-traveling self-propelled work machine; the sensing module (14) also comprises: a pressure sensor (141a), arranged between the operation member (112) and the connecting rod (111); a pressing member (146); when the grip part is subjected to a pushing force, the pressing member (146) applies a force along a preset linear direction to the pressure sensor (141a) so as to drive the pressure sensor (141a) to deform.
D: A power tool and an operation method therefor for fast locking and releasing a working accessory. The power tool comprises a housing (2), a motor (18) disposed in the housing, a main shaft (16) driven by the motor to output rotary power, and a chuck (3) used for locking and releasing a working accessory. The chunk comprises a core body (12) connected to the main shaft, multiple claws (14) movably disposed relative to the core body, and a jacket (13) sleeved on an outer side of the core body. Driven by relative movement between the jacket and the core body, the multiple claws are folded and unfolded relative to the core body. The power tool also comprises a control apparatus. The control apparatus can operably lock a position of the jacket or the core body relative to the housing, or can control the motor to be started according to a preset rotation direction and accordingly, relative movement is generated between the jacket and the core body.
Answer: D