Please select the most similar patent number from A, B, C and D. Which number is?
Disclosed is a collapsible storage fan, which pushes one end of a slide-limiting press plate to pass through a locking through-slot (52A) during normal usage of the fan by a locking mechanism (5), which comprises a downward pressing component (52), a limiting seat (53) and the slide-limiting press plate (51), so that the slide-limiting press plate is located at all the top faces of a movable front supporting seat (42), a fixed left and right supporting seat (41) and a movable rear supporting seat (43). Then, a pressure is applied to the slide-limiting press plate by the downward pressing component, so as to simultaneously abut the slide-limiting press plate against the movable front supporting seat, the fixed left and right supporting seat and the movable rear supporting seat. By using the present fan, the overall occupied space is greatly reduced, package and transportation are facilitated, transportation costs are saved and labour intensity is reduced. Furthermore, assembly procedure is effectively simplified, which facilitates the storage and the usage for the user, and is very safe and practical.
A: An electric spindle and a machine tool, comprising: a machine body assembly (1), provided with an air inlet (11) and a stator (12); a spindle core assembly (2), supported on the machine body assembly (1) by means of an upper bearing assembly (4) and a lower bearing assembly (5), the spindle core assembly (2) comprising a spindle core (21), a rotor (22), a pull rod assembly (24), and a chuck (23); and a push rod (3), extending into a spindle core inner hole from the upper end of the spindle core (21); the upper bearing assembly (4) comprises an upper bearing seat (41), an upper bearing (42), and a bearing pre-tensioning component (43), a closed inner cavity (44) being defined inside the upper bearing seat (41), the spindle core inner hole being in communication with the inner cavity (44), the upper bearing (42) and the bearing pre-tensioning component (43) being arranged in the inner cavity (44), the bearing pre-tensioning component (43) being supported between the upper bearing (42) and the upper bearing seat (41), the upper bearing seat (41) being provided with a piston chamber (46), the piston chamber (46) being in communication with the air inlet (11), a floating component (47) being disposed in the piston chamber (46), the floating component (47) abutting the bearing pre-tensioning component (43), and the spindle core inner hole and/or the pull rod assembly (24) and/or the push rod (3) being provided with a helical structure, in order to discharge the air in the inner cavity (44) outside via the spindle core inner hole after the spindle core assembly (2) is rotated.
B: A foldable electric fan, comprising a fan body (1), a turnover mechanism (2), a telescopic locking mechanism (3), and a base disc (4). The upper end of the base disc (4) is open and forms an accommodating space (41), and a mounting boss (42) is provided in the accommodating space (41); one end of the telescopic locking mechanism (3) is connected to the turnover mechanism (2), and the other end thereof is rotatably connected to the mounting boss (42); the fan body (1) is connected to the turnover mechanism (2), and the fan body (1) can be turned over and folded with respect to the telescopic locking mechanism (3); when the fan body (1) is stored, the fan body (1) can be folded on the end face of the upper end of the base disc (4) by means of the turnover mechanism (2) and the telescopic locking mechanism (3) while the turnover mechanism (2) and the telescopic locking mechanism (3) can be accommodated in the accommodating space (41). The fan is simple and compact in structure, small in size after being folded, space-saving, easy to store and convenient to carry.
C: A valve disc limiting shaft assembly, and a valve disc structure and a valve comprising same. The valve disc limiting shaft assembly comprises: a valve disc limiting shaft (9); at least one support seat (4), said support seat (4) having a first mounting aperture (41) provided thereon, a horizontal through channel (43) that communicates with the first mounting aperture (41) being provided on a lateral surface of a side of the support seat (4) which faces the valve disc limiting shaft (9), and an end part of the valve disc limiting shaft (9) moving into the first mounting aperture (41) via the horizontal through channel (43); and a stopper (3), which is arranged at the end part of the valve disc limiting shaft (9), comprising a main body part and at least two oppositely mounted extending parts, said extending parts having a first state in which the projection thereof onto the valve disc limiting shaft (9) falls on the side of the support seat (4) which faces the valve disc limiting shaft (9), and a second state in which the projection thereof onto the valve disc limiting shaft (9) at least partially falls into the horizontal through channel (43). This structure decreases difficulty of installation, the structure of the assembly parts is simplified, manufacturing is simplified, and costs are lower.
D: An adjustable intelligent digital display type device for positioning and punching an inclined hole in a sheet, comprising a base (1), a movable pressing plate (2), fixed pressing plates (3), an adjusting plate (4) and a supporting device (5). The base (1) is provided thereon with a cavity (11), an electric cylinder (14), a rack (13) and a first T-shaped sliding groove (12). Two stretching-out plates (28) are provided on the movable pressing plate (2), and a ratchet mechanism (21) is provided between the stretching-out plates (28) and is engaged with the rack (13). Two ends of the adjusting plate (4) are provided with arc plates (41), and the adjusting plate (4) is in sliding connection to the fixed pressing plates (3). The supporting device (5) comprises a first supporting plate (51) which has an arc structure, a second supporting plate (52) provided with a through hole (521), and a supporting rod (53). The present adjustable intelligent digital display type device for positioning and punching an inclined hole in a sheet has a reasonable structure, has the beneficial effects of the structure being simple, being convenient to use, having a high degree of intelligence, and universality being high, and effectively solves the problems of existing sheet hole punching equipment having low precision and being inconvenient for adjusting a punching angle.
Answer: B