Please select the most similar patent number from A, B, C and D. Which number is?
The present invention relates to a portable case for an electronic cigarette and a cartridge thereof. The portable case comprises: a top cover, a bottom cover pivotally connected to the top cover, at least two magnets provided in the top cover, and at least two magnets provided in the bottom cover, wherein the magnets provided in the top cover and close to a pivoted place of the top cover and the bottom cover are mutually attracted to the magnets provided in the bottom cover and far away from the pivoted place of the top cover and the bottom cover, and the magnets provided in the top cover and far away from the pivoted place of the top cover and the bottom cover are mutually exclusive to the magnets provided in the bottom cover and close to the pivoted place of the top cover and the bottom cover, so that the top cover is easy to open and close with respect to the bottom cover.
A: A cartridge (10) and an electronic cigarette (100). The cartridge (10) comprises: a main body (11) having a liquid storage cavity (110), a semi-closed end, and an open end opposite of the semi-closed end; a cartridge base cover (13) engaged with the open end of the main body (11), and provided with a liquid injection opening (130) and a pressure relief opening (132) in communication with the liquid storage cavity (110); and a rotating liquid injection cover (15) engaged with the cartridge base cover (13), and provided with a first communication opening (150) and a second communication opening (152). The rotating liquid injection cover (15) is rotatable about an axis relative to the cartridge base cover (13), and can be rotated to a position in which the first communication opening (150) is not aligned with the liquid injection opening (130), or a position in which the first communication opening (150) is in communication with the liquid injection opening (130) and the second communication opening (152) is in communication with the pressure relief opening (132). In the cartridge and the electronic cigarette, the rotating liquid injection cover disposed at a cartridge base is rotatable relative to the cartridge base cover when driven by an external force, such that liquid injection can be achieved simply by rotating and separating the position of the two to expose the liquid injection opening. The pressure relief opening is further provided at the cartridge base cover, and communicates with the exterior when the liquid injection opening is exposed, thereby preventing spilling of an injected liquid.
B: Provided is an electric balance scooter, comprising a top cover, a bottom cover, an inner cover, a rotating mechanism, two wheels, two wheel hub motors, a plurality of sensors, a power supply and a controller, wherein the top cover comprises a first top cover and a second top cover which are symmetrically arranged and can mutually rotate; the bottom cover is fixed to the top cover, and the bottom cover comprises a first bottom cover and a second bottom cover which are symmetrically arranged and can mutually rotate; the inner cover is fixed between the top cover and the bottom cover, and the inner cover comprises a first inner cover and a second cover which are symmetrically arranged and can mutually rotate; the rotating mechanism is fixed between the first inner cover and the second cover; the two wheels are rotatably fixed to two sides of the inner cover respectively; the two wheel hub motors are fixed in the two wheels respectively; the plurality of sensors are arranged between the bottom cover and the inner cover respectively; the power supply is fixed between the first bottom cover and the first inner cover; and the controller is fixed between the second bottom cover and the second inner cover, the controller is electrically connected to the plurality of sensors, the power supply and the wheel hub motors, and the controller controls the corresponding wheel hub motors to drive the corresponding wheels to rotate according to the sensed signals transmitted by the sensors.
C: A light connector, comprising a bottom cover, a top cover, and a pivot connection body located between the top cover and the lower cover. The pivot connection body comprises one or more concentric and stacked pivot connection units. Each pivot connection unit comprises a pivot connection ring and a male connection member provided on the side wall of the pivot connection ring. The top cover, the bottom cover, and the pivot connection rings enclose to form an accommodating cavity. A connection rod is provided inside the accommodating body. One end of the connection rod is connected to the bottom cover by means of a first screw, and the other end of the connection rod is connected to the top cover by means of a second screw. The male connection member matches a female connection member provided at an end portion of a light. The connector of the present invention enables a light to be adjusted within a range of 360°. When the angle of the light is determined, the second screw is re-screwed. In this case, the top cover and the bottom cover get close to each other and clamp the pivot connection body. Under the action of the clamping force, the rotation of the pivot connection units is limited.
D: Disclosed is a quick-change-type double-layer-piston three-dimensional cooled air cylinder, comprising an air cylinder top cover (1) and an upper-layer piston (2). The upper-layer piston (2) is arranged in the interior below the air cylinder top cover (1), a partition plate (3) is arranged below the upper-layer piston (2), a piston connection screw (4) is inserted in the partition plate (3) at the middle position, a lower-layer piston (5) is arranged below the partition plate (3), an air cylinder bottom cover (6) is arranged at an outer end of the bottom of the lower-layer piston (5), an air cylinder rotary fixing plate assembly (7) is arranged at the bottom of the air cylinder bottom cover (6), air cylinder fixing screws (202) are arranged at four corners of the bottom of the air cylinder rotary fixing plate assembly (7), air cylinder fixing plate fixing screws (201) are circumferentially arranged at the middle of the air cylinder rotary fixing plate assembly (7), outer walls of the left sides and right sides of the air cylinder top cover (1) and the air cylinder bottom cover (6) are respectively provided with water path inlet/outlet connection ports (203) and air path inlet/outlet connection ports (204), an air cylinder top cover water path structure (205) is inserted in the air cylinder top cover (1), and an air cylinder bottom cover water path structure (206) is inserted in the air cylinder bottom cover (6). The air cylinder has a compact structure and a small size, and is easy to mount and dismount, air cylinder top cover water paths and bottom cover water paths internally communicate to form a three-dimensional water cooling circulation system, a water path cooling plate is omitted, the height of a cylinder body is reduced, the optimal angle of a cylinder body assembly can be selected from a range of 360 degrees according to a mold structure and a hot nozzle, and angle adjustment is convenient and rapid.
Answer: A